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Communications in Computer and Information Science
244
Chunfeng Liu Jincai Chang Aimin Yang (Eds.)
Information Computing and Applications Second International Conference, ICICA 2011 Qinhuangdao, China, October 28-31, 2011 Proceedings, Part II
13
Volume Editors Chunfeng Liu College of Sciences Hebei United University Tangshan 063000, Hebei, China E-mail: [email protected] Jincai Chang College of Sciences Hebei United University Tangshan 063000, Hebei, China E-mail: [email protected] Aimin Yang College of Sciences Hebei United University Tangshan 063000, Hebei, China E-mail: [email protected]
ISSN 1865-0929 e-ISSN 1865-0937 ISBN 978-3-642-27451-0 e-ISBN 978-3-642-27452-7 DOI 10.1007/978-3-642-27452-7 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: Applied for CR Subject Classification (1998): C.2, D.2, C.2.4, I.2.11, C.1.4, D.4.7, H.3-4
Welcome to the proceedings of the International Conference on Information Computing and Applications (ICICA 2011), which was held in Qinhuangdao, China, October 28-30, 2011. As future-generation information technology, information computing and applications become specialized, information computing and applications including hardware, software, communications and networks are growing with ever increasing scale and heterogeneity, and becoming overly complex. The complexity is getting more critical along with the growing applications. To cope with the growing and computing complexity, information computing and applications focus on intelligent, self-manageable, scalable computing systems and applications to the maximum extent possible without human intervention or guidance. With the rapid development of information science and technology, information computing has become the third approach for scientific research. Information computing and applications is the field of study concerned with constructing intelligent computing, mathematical models, numerical solution techniques and using computers to analyze and solve natural scientific, social scientific and engineering problems. In practical use, it is typically the application of computer simulation, intelligent computing, Internet computing, pervasive computing, scalable computing, trusted computing, autonomy-oriented computing, evolutionary computing, mobile computing, applications and other forms of computation to problems in various scientific disciplines and engineering. Information computing and applications is an important underpinning for techniques used in information and computational science and there are many unresolved problems worth studying. The ICICA 2011 conference provided a forum for engineers and scientists in academia, industry, and government to address the most innovative research and development issues including technical challenges and social, legal, political, and economic issues, and to present and discuss their ideas, results, work in progress and experience on all aspects of information computing and applications. There was a very large number of paper submissions (865), representing six countries and regions. All submissions were reviewed by at least three Program or Technical Committee members or external reviewers. It was extremely difficult to select the presentations for the conference because there were so many excellent and interesting submissions. In order to allocate as many papers as possible and keep the high quality of the conference, we finally decided to accept 289 papers for presentation, reflecting a 33.2% acceptance rate. And 96 papers are included in this volume. We believe that all of these papers and topics not only provided novel ideas, new results, work in progress and state-of-the-art techniques in this field, but also stimulated future research activities in the area of information computing and applications.
VI
Preface
The exciting program of this conference was the result of the hard and excellent work of many individuals, such as the Program and Technical Committee members, external reviewers and Publication Chairs, all working under a very tight schedule. We are also grateful to the members of the local Organizing Committee for supporting us in handling so many organizational tasks, and to the keynote speakers for accepting to come to the conference with enthusiasm. Last but not least, we hope you enjoy the conference proceedings. October 2011
Chunfeng Liu Jincai Chang Aimin Yang
Organization
ICICA2011 was organized by the Hebei Applied Statistical Society (HASS), College of Science of Hebei United University, and sponsored by the National Natural Science Foundation of China, Northeastern University at Qinhuangdao, Yanshan University and Nanyang Technological University. It was held in cooperation with Communications in Computer and Information Science (CCIS) of Springer.
Executive Committee Honorary Chair Qun Lin
Chinese Academy of Sciences, China
General Chairs Yanchun Zhang Baoxiang Liu Yiming Chen
Victoria University, Australia Hebei United University, China Yanshan University, China
Program Chairs Chunfeng Liu Leizhen Wang Chunlai Chai
Hebei United University, China Northeastern University at Qinhuangdao, China Zhejiang Gongshang University, China
Local Arrangements Chairs Jincai Chang Aimin Yang
Hebei United University, China Hebei United University, China
Steering Committee Qun Lin Yuhang Yang MaodeMa Nadia Nedjah Lorna Uden Xingjie Hui Xiaoqi Li
Chinese Academy of Sciences, China Shanghai Jiao Tong University, China Nanyang Technological University, Singapore State University of Rio de Janeiro, Brazil Staffordshire University, UK Northeastern University at Qinhuangdao, China Northeastern University at Qinhuangdao, China
VIII
Organization
Xiaomin Wang Yiming Chen Maohui Xia Chunxiao Yu Yajuan Hao Dianxuan Gong Yajun Zhang
Northeastern University at Qinhuangdao, China Yanshan University, China Yanshan University, China Yanshan University, China Yanshan University, China Hebei United University, China Northeastern University, China
Publicity Chairs Aimin Yang Chunlai Chai
Hebei United University, China Zhejiang Gongshang University, China
Publication Chairs Yuhang Yang
Shanghai Jiao Tong University, China
Financial Chair Chunfeng Liu Jincai Chang
Hebei United University, China Hebei United University, China
Local Arrangements Committee Li Feng Songzhu Zhang
Yamian Peng Lichao Feng Dianxuan Gong Yuhuan Cui
Hebei United University, China Northeastern University at Qinhuangdao, China Northeastern University at Qinhuangdao, China Hebei United University, China Hebei United University, China Hebei United University, China Hebei United University, China
Secretaries Jingguo Qu Huancheng Zhang Yafeng Yang
Hebei United University, China Hebei United University, China Hebei United University, China
Jiao Gao
Program/Technical Committee Yuan Lin Yajun Li Yanliang Jin Mingyi Gao
Norwegian University of Science and Technology, Norway Shanghai Jiao Tong University, China Shanghai University, China National Institute of AIST, Japan
Organization
Yajun Guo Haibing Yin Jianxin Chen Miche Rossi Ven Prasad Mina Gui Nils Asc Ragip Kur On Altintas Suresh Subra Xiyin Wang Dianxuan Gong Chunxiao Yu Yanbin Sun Guofu Gui Haiyong Bao Xiwen Hu Mengze Liao Yangwen Zou Liang Zhou Zhanguo Wei Hao Chen Lilei Wang Xilong Qu Duolin Liu Xiaozhu Liu Yanbing Sun Yiming Chen Hui Wang Shuang Cong Haining Wang Zengqiang Chen Dumisa Wellington Ngwenya Hu Changhua Juntao Fei Zhao-Hui Jiang Michael Watts Tai-hon Kim
Huazhong Normal University, China Peking University, China University of Vigo, Spain University of Padova, Italy Delft University of Technology, The Netherlands Texas State University, USA University of Bonn, Germany Nokia Research, USA Toyota InfoTechnology Center, Japan George Washington University, USA Hebei United University, China Hebei United University, China Yanshan University, China Beijing University of Posts and Telecommunications, China CMC Corporation, China NTT Co., Ltd., Japan Wuhan University of Technology, China Cisco China R&D Center, China Apple China Co., Ltd., China ENSTA-ParisTech, France Beijing Forestry University, China Hu’nan University, China Beijing University of Posts and Telecommunications, China Hunan Institute of Engineering, China ShenYang Ligong University, China Wuhan University, China Beijing University of Posts and Telecommunications, China Yanshan University, China University of Evry, France University of Science and Technology of China, China College of William and Mary, USA Nankai University, China Illinois State University, USA Xi’an Research Insti. of Hi-Tech, China Hohai University, China Hiroshima Institute of Technology, Japan Lincoln University, New Zealand Defense Security Command, Korea
IX
X
Organization
Muhammad Khan Seong Kong Worap Kreesuradej Uwe Kuger Xiao Li Stefa Lindstaedt Paolo Li Tashi Kuremoto Chun Lee Zheng Liu Michiharu Kurume Sean McLoo R. McMenemy Xiang Mei Cheol Moon Veli Mumcu Nin Pang Jian-Xin Peng Lui Piroddi Girij Prasad Cent Leung Jams Li Liang Li Hai Qi Wi Richert Meh shafiei Sa Sharma Dong Yue YongSheng Ding Yuezhi Zhou Yongning Tang Jun Cai Sunil Maharaj Sentech Mei Yu Gui-Rong Xue Zhichun Li Lisong Xu Wang Bin Yan Zhang
Southwest Jiaotong University, China The University of Tennessee, USA King Mongkuts Institute of Technology Ladkrabang, Thailand Queen’s University Belfast, UK CINVESTAV-IPN, Mexico Division Manager, Knowledge Management, Austria Polytechnic of Bari, Italy Yamaguchi University, Japan Howon University, Korea Nagasaki Institute of Applied Science, Japan National College of Technology, Japan National University of Ireland, Ireland Queens, University Belfast, UK The University of Leeds, UK Gwangju University, Korea Technical University of Yildiz, Turkey Auckland University of Technology, New Zealand Queens University of Belfast, UK Technical University of Milan, Italy University of Ulster, UK Victoria University of Technology, Australia University of Birmingham, UK University of Sheffield, UK University of Tennessee, USA University of Paderborn, Germany Dalhousie University, Canada University of Plymouth, UK Huazhong University of Science and Technology, China Donghua University, China Tsinghua University, China Illinois State University, USA University of Manitoba, Canada University of Pretoria, South Africa Simula Research Laboratory, Norway Shanghai Jiao Tong University, China Northwestern University, China University of Nebraska-Lincoln, USA Chinese Academy of Sciences, China Simula Research Laboratory and University of Oslo, Norway
Ocean University of China, China Huazhong University of Science and Technology, China Nanyang Normal University, China University of Memphis, USA University of Versailles, France
Teaching Computer Graphics in Digital Game Specialty . . . . . . . . . . . . . . Hui Du and Lianqing Shu
91
XIV
Table of Contents – Part II
Discussion of Some Problems in Statistical Teaching . . . . . . . . . . . . . . . . . . Yan Gao, Xiuhuan Ding, and Linfan Li
98
Bio-inspired and DNA Computing The Existence and Simulations of Periodic Solutions of a Leslie-Gower Predator-Prey Model with Impulsive Perturbations . . . . . . . . . . . . . . . . . . . Kaihua Wang and Zhanji Gui
104
The Existence and Simulations of Periodic Solution of Leslie Predator-Prey Model with Impulsive Perturbations . . . . . . . . . . . . . . . . . . . Kaihua Wang, Wenxiang Zhang, and Zhanji Gui
113
Solutions Research of Ill-Posed Problem and Its Implementation . . . . . . . Yamian Peng, Taotao Yu, and Yali He
121
In Vitro Evaluation on the Effect of Radiation Sterilizion on Blood Compatibility and Genotoxicity of a Femoral Prosthesis . . . . . . . . . . . . . . . Guochong Chen, Qingfang Liu, and Wen Liu
129
Evaluation of the Effects of Sterilization by Irradiation on Biocompatibility and Adaption of a Coronary Artery Stent . . . . . . . . . . . . Wen Liu, Qingfang Liu, and Guochong Chen
138
Evaluation of the Effects of Sterilization by Irradiation on Histocompatibility and Adaption of a Central Vein Catheter . . . . . . . . . . . Wen Liu, Qingfang Liu, and Guochong Chen
147
Study of Environment Maintenance Feasibility of Polyvinyl Alcohol . . . . Juan Guo and Jin Zhang
156
Effectiveness Study of Agriculture Listed Corporation Based on BC2 . . . Lei Chen
163
The Evolution Analysis of Resistance Genes in Sorghum . . . . . . . . . . . . . . Ling Jin, Li Wang, Yakun Wang, Shuai Zhang, and Dianchuan Jin
171
Evolutionary Analysis of Cellulose Gene Family in Grasses . . . . . . . . . . . . Yakun Wang, Li Wang, Ling Jin, Jinpeng Wang, and Dianchuan Jin
178
Evolutionary Computing and Applications Application of Attributes Reduction Based on Rough Set in Electricity Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dajiang Ren
Synchronization of Uncertain Chaotic Systems with Different Structure in Driven and Response Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Junwei Lei, Aiqiang Xu, Yuliang Chen, and Guoqiang Liang
273
Information Education and Application Study on Innovative Culture Construction in Newly Established Local Undergraduate Course Academies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yanchun Shen, Yinpu Zhang, and Zhihua Hao
280
The Problems of Work Placements in Application-Oriented Undergraduate Colleges and Its Countermeasure Research . . . . . . . . . . . . . Yanchun Shen, Yinpu Zhang, and Minglin Yao
286
XVI
Table of Contents – Part II
Using PERT/CPM Technology for the Development of College Graduates Seeking Employment in Project Planning . . . . . . . . . . . . . . . . . . Xiaoqing Lu, Shuming Guan, Ruyu Tian, and Wenyi Zhang The Research for Effecting to Basic Mathematic Based on PCA . . . . . . . . Junna Jiang, Linlin Liu, and Xinchun Wang Research and Application of Five Rings Model in Mathematics Courses Reformation for Engineering Students in Independent College . . . . . . . . . Nan Ji, Qiuna Zhang, and Weili Chen Practices and the Reflections on the Bilingual Education . . . . . . . . . . . . . . Hai-chao Luo, Kai Zhou, Teng Chen, and Wei Cao
Information Specialty Experiment Remote Tutor System Development and Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Xiu Hui Fu, Li Ping Fan, and Shu Li Ouyang
338
Research on the Model of Practice Teaching Base on Project Driven Teaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Xiu Hui Fu and Li Ping Fan
344
The Discussion on the Teaching Reform of the “Electromagnetic Fields and Electromagnetic Waves” Based on “Field Techniques” . . . . . . . . . . . . Yinpu Zhang, Yanchun Shen, and Minglin Yao
350
Fuzzy Comprehensive Evaluation Model in Work of Teacher Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Xiaoling Liu, Haijun Chen, and Feng Yan
358
Application of Simple Examples in Experiment Teaching about Complex Function and Integral Transform . . . . . . . . . . . . . . . . . . . . . . . . . . Yan Yan, Dianchuan Jin, Yankun Li, Huijuan Zhao, and Xining Li
Dynamic Construction of Power Voronoi Diagram . . . . . . . . . . . . . . . . . . . . Yili Tan, Lihong Li, and Yourong Wang
660
XX
Table of Contents – Part II
The Research for Effecting to Traffic Congestion of Tangshan Based on PCA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Junna Jiang, Caidonng Bian, Yili Tan, and Xueyu Mi Study on Distribution Route Choice for Explosive . . . . . . . . . . . . . . . . . . . . Xue-yu Mi, Peng Zhang, Zheng Li, Bo Dong, and Li-fen Yi
668 676
Research on the Component Description Method of General Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yan-pei Liu, Jun Chen, and Yan-cui Li
683
The Existence and Simulations of Periodic Solution of a Two-Species Cooperative System with Impulsive Perturbations . . . . . . . . . . . . . . . . . . . . Kaihua Wang, Yan Yan, and Zhanji Gui
Social Networking and Computing Empirical Analysis on Relation between Domestic Tourism Industry and Economic Growth in China . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wang Liangju, Li Wanlian, and Wang Yongpei
102
Study of Coordinated Development between Urban Human Settlement and Economy Based on Entropy Weight Method . . . . . . . . . . . . . . . . . . . . . Wenyi Zhang, Cuilan Mi, and Shuming Guan
Mining the Concise Patterns for Service Reliability Prediction . . . . . . . . . Ying Yin, Xizhe Zhang, and Bin Zhang
167
Table of Contents – Part I
Study on the Current Situation and Coordination Policies Concerning the Regional Differences in Tourism Investment Environment of Hebei Province . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wei Guo, Fang Lv, and Na Song
XXIII
174
The Mathematical Model of the College Students’ Employment and Analytical from the Perspective of Economy . . . . . . . . . . . . . . . . . . . . . . . . . Cheng Lijun, Kou Yilei, and Zhao Haiyan
181
The Foundation of the Mathematical Model of Economic Impact and the Analysis of the Effect on the Economy of Shanghai World Expo . . . . Lijun Cheng and Lina Wang
The Research and Application of Fuzzy EntropyWeight Comprehensive Evaluation Method in Paper Quality Evaluation . . . . . . . . . . . . . . . . . . . . . Cuilan Mi and Baoxiang Liu
277
Global Exponential Stability Analysis for Uncertain Stochastic Neural Networks with Discrete and Distributed Time-Varying Delays . . . . . . . . . Guan Wei and Zeng Hui
Internet and Web Computing Mathematical Formula Design Based on Mobile Learning Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yanan Li, Hao Zhang, Yanling Meng, and Honghui Wang Network-Based Construction of Open Virtual Laboratory Teaching Platform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dong Lu, Chen Lian Qing, Xian Yu Dan Qian, Cui Ying Shan, Kan Lian He, and Song Li Chuan An Adaptive Routing Algorithm for Ad Hoc Network . . . . . . . . . . . . . . . . . Sihai Zheng, Layuan Li, and Yong Li
421
427
434
XXVI
Table of Contents – Part I
An Efficient Clustering Algorithm for Mobile Ad Hoc Networks . . . . . . . . Sihai Zheng, Layuan Li, Yong Li, and Junchun Yuan
442
Research on Semantic Web Service Composition Based on Ontology Reasoning and Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Jianfeng Zhang, Piyuan Lin, Peijie Huang, and Guangfa Wu
450
A Study of Indoor Distributed Calculation Model of Mobile Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yinpu Zhang, Fang Wang, Yanchun Shen, and Wenfeng Huo
458
Research of Semantic Web Model and Reasoning Based on F-Logic . . . . . Guorong Qin, Tao He, and Liping Li Design and Implementation of Educational Administration System on the Basis of C/S and B/S Heterogeneous Architecture . . . . . . . . . . . . . . . . Yan Jiang Strategic Measures of Network Marketing of SME Brand . . . . . . . . . . . . . . Zhou Zhigang
466
473 482
Design and Accomplishment of Campus WebGIS Based on B/S Model—A Case-Study of Hebei Polytechnic University . . . . . . . . . . . . . . . . Xiaoguang Li, Fenghua Wu, and Shunxi Yan
On the Development of Engineering Management and the Education of Such Personnel in This Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Jiefang Tian, Xingguo Wang, and Wei Ming
568
Research on the Urban Ecological Bearing Capacity of Resource-Based Cities—Tangshan as an Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ma Jingzhong
Prediction Based on Wavelet Transform and Support Vector Machine . . . Xiaohong Liu, Yanwei Zhu, Yongli Zhang, and Xinchun Wang
618
Schur Convexity for a Class of Symmetric Functions . . . . . . . . . . . . . . . . . . Shu-hong Wang, Tian-yu Zhang, and Bo-yan Xi
626
The Study on Clutch Shift Control Based on Sliding-Mode . . . . . . . . . . . . Zhang Guang Hui
635
XXVIII
Table of Contents – Part I
Numerical Simulation Program of an Elastic Membrane Considering the Fluid-Structure Interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Liu Jian-Min and Cai Zhen-Xiong
643
Green Theory Research and Practice on Indoor Air Pollution by Overall Process Controlling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Liu Jun and Zhuo Yuguo
651
Regularization Method Combined with Parameter Competitive Criterion for Model-Plant Performance Matching of Aircraft Engine . . . . Lifeng Wang and Datian Zhong
657
Study of Flow Control System Model Based on Bypass Protocol Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sujuan Zhang, Yanli Zhang, and Zhijie Fan
A*H over Weak Hopf Algebras Yan Yan1, Xinghua Ma1, Dongmei Li2, Liping Du1, and Yankun Li1 1
2
College of Sciences, Hebei United University, Department of Automation Engineering, Tangshan Industrial Vocational Technical College, Tangshan, Hebei, China {Yan Yan,yanjxky}@126.com
Abstract. The notion of a Hopf algebra was developed by algebraic topologists abstracting the work of H.Hopf on manifolds in 1941.In this paper, we mainly study a right twisted smash product A*H over weak Hopf algebras and investigate their properties.The concet of a right twisted smash product algebras over weak Hopf akgebras is constructed. Let H be a weak Hopf algebra and A an H-module algebra,we give a sufficient and necessary condition for a right twisted smash product A*H to be a weak bialgebra . Simultaneously,we also give a sufficient condition for A*H to be a weak Hopf algebra. Keywords: Right twisted smash product algebra, weak Hopf algebra, module algebra.
For the foundations of weak Hopf algebra theory we refer the reader to[1]. Throughout this paper, k denotes a field. We use Sweedler’s notation for the comultiplication: Δ( x) = x1 ⊗ x2 .[2] Definition 2.1. Let K be a field and H =< μ, η, , ε > be both an associative algebra over K and a coalgebra over K. If H satisfies the following conditions1) − 3) , it is
caller a weak bialgebra. If it satisfies the following conditions1) − 4) , it is caller a weak Hopf algebra with a weak antipode S. 1) (xy) = (x) ⊗ (y), 2)11 ⊗ 12 ⊗ 13 = 11 ⊗ 1112 ⊗ 12 = 11 ⊗ 12 11 ⊗ 12 , 3)ε(xyz) = ε(xy1 )ε(y 2 z) = ε(xy 2 )ε(y1z), 4)x1S(x 2 ) = ε(11 x)12 ,S(x1 )x 2 = 11 ε(x12 ),S(x1 )x 2S(x 3 ) = S(x). For any weak Hopf algebra H, the following conditions are equivalent
1)H is a Hopf a lg ebra, 2) (1) = 1 ⊗ 1, 3)ε(xy) = ε(x)ε(y), ∀x, y ∈ H 4)ε(11 x)12 = 11 ε(x12 ) = ε(x), ∀x ∈ H. Let H be a weak bialgebra, the linear maps Π L , Π R : H → H is defined by the formulas Π L (x) = ε(11 x)12 , Π R (x) = 11 ε(x12 ) and we denote their images by H L = Π L (H) and H R = Π R (H) . Clealy, they are the subalgebras of H. G.Bohm and F.Nill[1] proved that in a weak Hopf algebra H, for all x, y ∈ H , we have Π L (x) = ε(11 x)12 = x1S(x 2 ) = ε(S(x11 ))12 = S(11 )ε(12 x) Π R (x) = 11 ε(x12 ) = S(x1 )x 2 = 11 ε(12 S(x)) = ε(x11 )S(12 ) And for all x ∈ H , we have the following relations
S(Π L (x)) = Π R (S(x)), x1 ⊗ x 2S(x 3 ) = 11 x ⊗ 12 ,
S(Π R (x)) = Π L (S(x)) S(x1 )x 2 ⊗ x 3 = 11 ⊗ x12
x1 ⊗ S(x 2 )x 3 = x11 ⊗ S(12 ), x1S(x 2 ) ⊗ x 3 = S(11 ) ⊗ 12 x Moreover, the relation[4] x1S(x 2 )x 3 = x also holds. In fact, x1S(x 2 )x 3 = Π L (x1 )x 2 = ε(11 x1 )12 x 2 = x
A*H over Weak Hopf Algebras
3
If H is a weak Hopf algebra, its weak antipode S is both an anti-multiplicative map and an anti-comultiplicative map, that is, for all x, y ∈ H S(xy) = S(y)S(x),S(1) = 1,S(x)1 ⊗ S(x) 2 = S(x 2 ) ⊗ S(x1 ), ε(S(x)) = ε(x) Definition 2.2. Let A be an H-bimodule algebra[5]. A right twisted weak smash product A*H is defined on the vector space A ⊗ H . Define a multiplication[6]
(a ⊗ h)(b ⊗ g ) = a (h1 → b ← S (h3 )) ⊗ h2 g on tensor space A ⊗ H , for all a, b ∈ A, h, l ∈ H . Let a*x denote the class of a ⊗ x in A ⊗ H ,the multiplication in A*H is given by the familiar formula ∧
∧
∧
∧
11 → a ⊗ 12 h = a ⊗ h , a ← S (12 ) ⊗ 11 h = a ⊗ h
3
Right Twisted Smash Prodouct Algebras over Weak Hopf Algebras
In this section,let H be a weak Hopf algebra with a bijective weak antipode S and A a H-module algebra.[12][13] Lemma 3.1. Let A be an H-module algebra and A*H the right twisted smash product algebta ,then ∀a, b ∈ A,g, h ∈ H, the following conditions hold[7]
1)(1* h)(1* g) = 1* hg ˆ *1) ˆ = ab *1ˆ 2)(a *1)(b ˆ 3)(a *1)(1* h) = a * h ˆ = h → a ← S(h ) * h 4)(1* h)(a *1) 1 3 2 Proof: By the definition of multiplication of A*H , the 4th condition is clearly true . Let ∀a, b ∈ A,g, h ∈ H, we have
(1* h)(1*g) = (h1 → 1 ← S(h 3 )) * h 2 g = (Π L (h1 ) → 1 ← S(h 3 )) * h 2 g = 1 ← S(1ˆ ) * ε(S(h )1ˆ )h g 2
2
1
1
= 1* hg ˆ *1) ˆ = a(1ˆ → b ← S(1ˆ )) *1ˆ (a *1)(b 1 3 2 = ab *1ˆ ˆ (a *1)(1* h) = a(1ˆ1 → 1 ← S(1ˆ3 )) *1ˆ2 h = a*h
4
Y. Yan et al.
Therefore, we may write : ha = (h1 → a ← S(h 3 )) * h 2 , ah = a * h . Lemma 3.2. The right twisted smash product A*H is a tensor product coalgebra as a coalgebra[8],whose comultiplication is given by Δ* (a * h) = (a1 * h1 ) ⊗ (a 2 * h 2 ) ,and
whose counit is given by ε* (a * h) = ε A (a)ε H (h) , for all ∀a ∈ A, h ∈ H. Proof (id ⊗ Δ* )Δ* (a * h) = (id ⊗ Δ* )((a1 * h1 ) ⊗ (a 2 * h 2 )) = (a1 * h1 ) ⊗ (a 2 * h 2 ) ⊗ (a 3 * h 3 ) = (Δ* ⊗ id)Δ* (a * h) (ε* ⊗ Δ* )Δ* (a * h) = (ε* ⊗ Δ* )((a1 * h1 ) ⊗ (a 2 * h 2 )) = εA (a1 )a 2 * ε H (h1 )h 2 = a *h Similarly,we have (id ⊗ ε* )Δ* (a * h) = a * h . So (A*H,Δ* , ε* ) is a coalgebra. Next, we give the condition for a right twisted smash product A*H to be a weak bialgebra and a weak Hopf algebra. Let A be a weak H-double module and H left regular module. Lemma 3.3. Let A be a weak bialgebra. Then Δ* is a multiplication map, that is
∀a * h, b * g ∈ A * H, Δ* ((a * h)(b * g)) = Δ* (a * h)Δ* (b * g) if and only if the following condition holds: ((h1 → a ← S(h 4 ))1 * h 2 ) ⊗ ((h1 → a ← S(h 4 ))2 * h 3 ) = (11 (h1 → a1 ← S(h 3 )) * h 2 1ˆ1 ) ⊗ (12 (h 4 → a 2 ← S(h 6 )) * h 5 1ˆ2 ) Proof
Δ* ((a * h)(b * g)) = Δ* (a(h1 → b ← S(h 3 )) * h 2 g) = (a1 (h1 → b ← S(h 4 ))1 * h 2 g1 ) ⊗ (a 2 (h1 → b ← S(h 4 ))2 * h 2 g 2 ) = (a1 (h1 → b1 ← S(h 3 )) * h 2 g1 ) ⊗ (a 2 (h 4 → b 2 ← S(h 6 )) * h 5 g 2 ) = ((a1 * h1 )(b1 * g1 )) ⊗ ((a 2 * h 2 )(b 2 * g 2 )) = Δ* (a * h)Δ* (b * g) ˆ = Δ (1* h)Δ (a *1) ˆ ⇐ Δ* ((1* h)(a *1)) * * That is : ((h1 → a ← S(h 4 ))1 * h 2 ) ⊗ ((h1 → a ← S(h 4 ))2 * h 3 ) = (11 (h1 → a1 ← S(h 3 )) * h 2 1ˆ1 ) ⊗ (12 (h 4 → a 2 ← S(h 6 )) * h 5 1ˆ2 )
ˆ = ((1*1) ˆ ⊗ Δ (1*1))( ˆ Δ (1*1) ˆ ⊗ (1*1)) ˆ . Similarly,we have Δ*2 (1*1) * * Lemma 3.5. Let A be a weak bialgebra. Assume that:[9]
a ← S(h1 ) * h 2 = a ← S(h 2 ) * h1 Then the following relations hold in A*H: (1)ε* ((a * x)(b * y)(c * p)) = ε* ((a * x)(b1 * y1 ))ε* ((b 2 * y 2 )(c * p)) ⇔ ε A (a(x1 → b ← S(x 5 ))(x 2 y1 → c ← S(x 4 y3 )))ε H (x 3 y 2 ) = ε A (a(x1 → b1 ← S(x 3 )))ε A (b 2 (y 2 → c ← S(y 4 )))ε H (x 2 y1 )ε H (y3 ) (2)ε* ((a * x)(b * y)(c * p)) = ε* ((a * x)(b 2 * y 2 ))ε* ((b1 * y1 )(c * p)) ⇔ ε A (a(x1 → b ← S(x 5 ))(x 2 y1 → c ← S(x 4 y3 )))ε H (x 3 y 2 ) = ε A (a(x1 → b 2 ← S(x 3 )))ε A (b1 (y1 → c ← S(y 3 )))ε H (x 2 y 4 )ε H (y 2 ) Proof: (1) ε* ((a * x)(b * y)(c * p)) = ε A (a(x1 → b ← S(x 5 ))(x 2 y1 → c ← S(x 4 y3 )))ε H (x 3 y 2 p) ε* ((a * x)(b1 * y1 ))ε* ((b 2 * y 2 )(c * p)) = ε A (a(x1 → b1 ← S(x 3 )))ε A (b 2 (y 2 → c ← S(y 4 )))ε H (x 2 y1 )ε H (y3 p)
∵ ε* ((a * x)(b * y)(c * p)) = ε* ((a * x)(b1 * y1 ))ε* ((b 2 * y 2 )(c * p)) ∴ε A (a(x1 → b ← S(x 5 ))(x 2 y1 → c ← S(x 4 y3 )))ε H (x 3 y 2 p) = ε A (a(x1 → b1 ← S(x 3 )))ε A (b 2 (y 2 → c ← S(y 4 ))) ε H (x 2 y1 )ε H (y 3 p)
5
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Y. Yan et al.
Let p = 1 , then we have: ε A (a(x1 → b ← S(x 5 ))(x 2 y1 → c ← S(x 4 y3 )))ε H (x 3 y 2 ) = ε A (a(x1 → b1 ← S(x 3 )))ε A (b 2 (y 2 → c ← S(y 4 ))) ε H (x 2 y1 )ε H (y3 ) ⇐ ε* ((a * x)(b * y)(c * p)) = ε A (a(x1 → b ← S(x 5 ))(x 2 y1 → c ← S(x 4 y3 )))εH (x 3 y2 p) = ε A (a(x1 → b ← S(x 5 ))(x 2 y1 → c ← S(x 4 y3 )))εH (x 3 y2 )εH (y4 p) = ε A (a(x1 → b1 ← S(x 3 )))ε A (b2 (y2 → c ← S(y5 ))) ε H (x 2 y1 )ε H (y3 )ε H (y 4 p) = ε A (a(x1 → b1 ← S(x 3 )))ε A (b2 (y2 → c ← S(y 4 ))) ε H (x 2 y1 )ε H (y 3 p) = ε* ((a * x)(b1 * y1 ))ε* ((b 2 * y 2 )(c * p)) Similarly, we have (2)ε* ((a * x)(b * y)(c * p)) = ε* ((a * x)(b 2 * y2 ))ε* ((b1 * y1 )(c * p)) ⇔ ε A (a(x1 → b ← S(x 5 ))(x 2 y1 → c ← S(x 4 y3 )))εH (x 3 y 2 ) = ε A (a(x1 → b 2 ← S(x 3 )))ε A (b1 (y1 → c ← S(y3 ))) ε H (x 2 y 4 )ε H (y 2 ) Definition 3.6. For all a * h ∈ A * H , we have Π *L (a * h) = ε* ((11 *1ˆ1 )(a * h))(12 *1ˆ2 ) , Π *R (a * h) = (11 *1ˆ1 )ε* ((a * h)(12 *1ˆ 2 )) . Theorem 3.7. Let A be a weak bialgebra. Assume that: a ← S(h1 ) * h 2 = a ← S(h 2 ) * h1 Then A*H is a weak bialgebra if and only if lemma 3.3 and lemma 3.5 hold. In this situation[10][11],if (A,SA ), (H,SH ) are weak Hopf algebra, and satisfy the following conditions: (1)a1 (Π LH (h) → SA (a 2 )) = Π AL (a)ε H (h)
ˆ . then A*H is a weak Hopf algebra with a weak antipode S* (a * h) = (1*S(h))(SA (a) *1) Proof: Clearly, A*H is a weak bialgebra if and only if lemma3.3 and lemma3.5 hold. Next, we proof that A*H is a weak Hopf algebra.
∵ ∀a ∈ A, ∀h ∈ H, ˆ S* (a * h) = (1*S(h))(SA (a) *1) = (S(h 3 ) → SA (a) ← S2 (h1 )) *S(h 2 )
A*H over Weak Hopf Algebras
7
So, we get
(a1 * h1 )S* (a 2 * h 2 ) = (a1 * h1 )(S(h 4 ) → SA (a 2 ) ← S2 (h 2 )*S(h 3 )) = a (Π L (h) → S (a )) *1ˆ 1
A
2
= Π (a)ε H (h) *1ˆ ˆ * h)(1 *1)) ˆ ε* ((11 *1)(a 2 ˆ = ε* (11 (1ˆ1 → a ← S(1ˆ3 )) *1ˆ2 h)(12 *1) ˆ = ε (1 a * h)(1 *1) L A
*
1
2
= Π LA (a)ε H (h) *1ˆ ˆ * h)(1 *1)) ˆ ∴ (a1 * h1 )S* (a 2 * h 2 ) = ε* ((11 *1)(a 2 Similarly, we have
ˆ ε ((a * h)(1 *1)) ˆ ∴ S* (a1 * h1 )(a 2 * h 2 ) = (11 *1) * 2 Finally, we have S* (a1 * h1 )(a 2 * h 2 )S* (a 3 * h 3 ) = S* (a1 * h1 )Π *L (a 2 * h 2 ) = (S(h 3 ) → S(a1 ) ← S2 (h1 ) *S(h 2 ))Π*L (a 2 * h 4 ) ˆ = (S(h 3 ) → S(a1 ) ← S2 (h1 ) *S(h 2 ))ε* (11 a 2 * h 4 )(12 *1) = S* (a * h) Thus, A*H is a weak Hopf algebra. The proof is completed.
References 1. Bohm, G., Nill, F., Szlachanyi, K.: Weak Hopf Algebras I: Integral Theory and C* structure. J. Algebra, 385 (1999) 2. Sweedler, M.E.: Hopf Algebras, Berjamin, New York (1969) 3. Hirata, K., Sugano, K.: On Semisimple extensions and separable extensions over non commutative rings. J.Math. Soc. Japan 18(4), 360–373 (1966) 4. Cohen, M., Fishman, D.: Hopf algebra actions. J. Algebra 10, 363–379 (1986)
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5. Wang, S., Li, J.q.: On Twisted Smash Products for Bimodules Algebras and the Drinfel‘d Double. Comm. Algebra 26, 2435–2444 (1998) 6. Zheng, N.: Smash Biproduct Over Weak Hopf Algebras. Advances in Mathematics (05) (2009) 7. Shi, M.: The Complexity of Smash product. Advances in Mathematics (05) (2008) 8. Jiao, Z., Li, J.: The L-R Weak Smash Product over Weak Hopf Algbras, vol. (01) (2009) 9. Ling, J.: Maschke-Type Therems for Weak Smash Coproducts. Journal of Mathematical Re-Search and Exposition (04) (2009) 10. Yin, Y., Zhang, M.: The Structure Theorem for Weak Hopf Algebras. Advances in Mathematics (06) (2009) 11. Ju, T.: Cocyclic Module Constructed By The Right Adjoint Action Of Hopf Algebras. Journal of Mathematics (02) (2010) 12. Ju, T.: Cocyclic Module Constructed By The Right Adjoint Action of Hopf Algebras. Journal of Mathematics (02) (2010) 13. Ju, T.: The cotwists for Hopf algebras. Journal of Natural Science of Heilongjiang University (01) (2010)
Study on the Establishment of Mathematical Model for Male’s Foot Taisheng Gong1, Quane Wei1, Rui Fei2, Yunqi Tang1, Gaoyong Liang3, and Jun Lai3 1
School of Resource and Environment, Shaanxi University of Science and Technology, Shaanxi 710021, P.R. China 2 The Research Institute of China Leather and Footwear Industry, Beijing 100015, P.R. China 3 The Quartermaster Equipment Institute of the General Logistics Department, Beijing 100010, P.R. China
Abstract. Footwear design is based on the foot shape, in order to meet people’s requirement of wearing comfortable shoes, it should match the shoes and the feet as much as possible when we design shoes. Through using manual measurement, it obtained the data of fifteen major controlling parts from 654 adult males, SPSS (Statistical Product and Service Solutions) softwear was applied to establish the mathematical model of the relationship between the size of each foot part, meanwhile the value of other related parts was estimated by the measured value of basic parts. The experimental results show that the predictive value of this model is accurate. Keywords: male, foot shape rule, mathematical model, manual measurement, fitness.
1
Introduction
The footwear design concept of “human-oriented” can not be separated from the basis of the analysis of human foot, foot measuring is the necessary means to grasp the foot features, meanwhile it provides the scientific basis for the design of comfortable shoes[1]. However, in the process of foot measuring, for the measuring site which choosing the bones as reference points, there is a non-contact measurement method that is difficult to determine the bone points accurately resulting in the inaccurate measurement precision, meanwhile it costs very much[2]. Contact measurement results are accurate, but it needs a heavy workload. In this paper, SPSS softwear is used to process a large number of foot data, meanwhile it is applied to establish the mathematical model of the relationship between the size of each foot part, the value of other related parts is estimated by the measured value of basic parts. It not only provides the certain precision but also reduces body measurement site, and it greatly reduces the workload measurement.
Research Object: Total samples are 654 adult males whose age is from 18 to 50. Measurement Method: The related measuring points are marked on the characteristics parts of foot by pen, and the relevant data of all parts of foot are measured directly by measuring tools such as tape, high volume sampler. Meanwhile foot contour line is drawn through the footprint which made by the footprint devices, finally we measure and analyze the data. Measuring Site: According to GB/3293.1-1998[3, 4], 15 basic indicators are chosen, the name of the specific measuring site can be seen in table 1. Table 1. Measuring site of foot shape No. J1
Measuring site Length of Foot
No. J6
Measuring site Width of Foot
No. J11
J2
The Position of the 1st Metatarsophalangeal Joint The Position of the 5th Metatarsophalangeal Joint The Position of Flank
J7
Ball Girth
J12
J8
Front Tarsal Girth
J13
The Height of Outer Ankle Down-edge
J9
The Inside-width of the 1st Metatarsophalangeal Joint Silhouette The Outside-width of the 5th Metatarsophalangeal Joint Silhouette
J14
The Height of Thumb
J15
The Height of Heel Site-directed
J3
J4
J5
The Position of Heel Heart
J10
3
Measurement Results and Analysis
3.1
Correlation Tests
Measuring site The Outsidewidth of the Flank Silhouette Overall Width of Heel Heart
There are two relationship between variables: One is the deterministic relation, the other is the uncertainty relation. The relations between length of foot and ball girth in the size of human foot shape are as follows: the people with different length of foot, their ball girth are not necessarily the same; the people with the same ball girth, their
Study on the Establishment of Mathematical Model for Male’s Foot
11
Table 2. Correlation coefficient matrix
Length of Foot J1 Ball Girth J7
Correlation coefficient P value Correlation coefficient
Width of Foot J6 The Height of Outer Ankle Down-edge J13 The Height of Heel Site-directed J15 The Height of Thumb J14 Front Tarsal Girth J8 The Position of the 1st Metatarsophalangeal Joint J2 The Inside-width of the 1st Metatarsophalangeal Joint Silhouette J9 The Position of the 5th Metatarsophalangeal Joint J3 The Outside-width of the 5th Metatarsophalangeal Joint Silhouette J10 Overall Width of Heel Heart J12 The Outside-width of the Flank Silhouette J11 The Position of Flank J4 The Position of Heel Heart J5
ff
d b ll i h
Length of foot J1 1.000
Ball girth J7
Width of foot J6 0.019 0.632 0.012
0.240
0.240 0.071 1.000
P value Correlation coefficient
0.071 0.019
0.012
0.767 1.000
P value Correlation coefficient
0.632 0.289
0.767 0.312
0.011
P value
0.0005
0.0003
0.800
Correlation coefficient
0.241
0.218
-0.028
P value Correlation coefficient
0.0001 0.241
0.002 0.294
0.473 -0.044
P value Correlation coefficient
0.0004 0.545
0.0002 0.827
0.263 -0.03
P value Correlation coefficient
0.0009 0.057
0.002 -0.018
0.393 0.625
P value
0.147
0.642
0.0004
Correlation coefficient
0.057
-0.014
0.875
P value
0.142
0.721
0.001
Correlation coefficient
0.155
-0.057
0.478
P value
0.0008
0.144
0.0001
Correlation coefficient
0.013
-0.008
0.931
P value
0.743
0.835
0.0006
Correlation coefficient
0.083
0.094
0.605
P value Correlation coefficient
0.033 0.038
0.016 0.023
0.0002 0.085
P value
0.336
0.416
0.005
Correlation coefficient
0.993
0.573
0.002
P value Correlation coefficient
0.0003 0.354
0.003 -0.021
0.578 0.615
P value
0.009
h d
i df
i
0.588
b
i
l
0.002
l
ih h
12
T. Gong et al.
length of foot are not the same all the time. It shows that the relations between length of foot and ball girth are not the determined function, but in general, people with the longer feet, the longer ball girth they have, their relationship is related correlation. Generally speaking, in the condition of large sample capacity, it requires the significant level of P value is not more than 0.05, then the linear relationship between two variables is remarkable, meanwhile the linear regression equation is meaningful. Table 2 shows that the correlation between J1 and J2,J6,J7,J9,J10,J11 is not significant; the correlation between J7 and J1,J2,J3,J6,J9,J10,J11 is not significant; the correlation between J6 and J1,J4,J7,J8,J13,J14,J15 is not significant; meanwhile the correlation between J1,J6 and J7 is not significant either. Therefore, there is simple regression equation and binary regression equation in foot regression analysis. 3.2
Regression Model Based on SPSS Softwear
3.2.1 Determination of Variables Regression analysis is a statistical method that studying whether there is a linear relationship or non-linear relationship between a dependent variable or multiple dependent variables and a dependent variable. Basic parts of the selected feet (dependent variable) should be followed: the basic parts are the important parts; the human feet which determined by the basic parts must cover the crowd as many as possible the number of basic parts must be as little as possible; basic parts should be easy to measure, familiar and easy for the public to accept. At the same time, combining with 2.1’s analysis, we will select J1,J6,J7 as the basic parts to establish the regression equation of controlling parts.
①
③
④
②
3.2.2 Establishment of Regression Model [5, 6] We select front tarsal girth as dependent variable in order to establilsh the detailed regression equation, and the analysis results are as follows: Table 3. Model comprehensive analysis d Mode
R
R2
Adjusted R2
1 2 3
0.827a 0.835b 0.835c
0.684 0.698 0.700
0.684 0.697 0.698
Estimate standard error 6.10489 5.97796 5.96269
Note: a Predictors: (Constant), Ball Girth; b Predictors: (Constant), Ball Girth, Length of Foot; c Predictors: (Constant), Ball Girth, Length of Foot, Width of Foot; d Dependent Variable: Front Tarsal Girth.
Study on the Establishment of Mathematical Model for Male’s Foot
13
Table 3 is the comprehensive analysis form for 3 kinds of models, R is multiple correlation coefficient of models, R2 is the coefficient of determination. R2 reflects the ratio that explained by the dependent variable in total variation of variable through regression relation. As shown in table 3, R2 is 0.7 in mode 1, it is shown that the regression relation under mode 1 can explain 70% of the variation of the dependent variable. As can be seen from the adjusted R2 in table 3, with the introduction of new variables from top to bottom, the ratio that the variation explained by the model in the total variation becomes bigger and bigger, especially, model 2 increases by 1.4 percentage points than model 1. Table 4 is the significant test results of regression coefficient of three kinds of models, statistics of three models can be seen from table 4: F1=1413.8; F2=751.731; F3=505.172. Its significance is less than 0.05, therefore 3 kinds of regression models are statistically significant. Table 4. Analysis of variance number d Mode 1 2 3
F value 1413.8 751.7 505.2
Significant Sig. 0.0002 a 0.0007 b 0.0002 c
Note: a Predictors: (Constant), Ball Girth; b Predictors: (Constant), Ball Girth, Length of Foot; c Predictors: (Constant), Ball Girth, Length of Foot, Width of Foot; d Dependent Variable: Front Tarsal Girth.
Table 5 contains the coefficient of regression equation and the test results of the regression equation coefficient, coefficient significant test is using t-test. The results of standardized and not standardized were given by the coefficient of regression equation, after the equation is standardized, there is no constant. In mode 1, the constant of not standardized regression equation is 39.98, the variable coefficient is 0.848; however the variable coefficient of standardized equation is 0.827, the corresponding confidence level is 0.0000, 0.0000 is significantly less than common cinfidence level 0.01, so we can regard these coefficient as remarkable. However, in model 3, the confidence level of the coefficient of width of foot is 0.0380 which is more than 0.01. As can be seen from the analysis of table 3, variation degree of variable which are interpretable in mode 2 is larger than in mode 1. Variation degree of variable which is interpretable in the mode 3 is larger 0.1 percentage point than in the mode 2, so let us take comprehensive consideration, we will choose the regression coefficients in mode 2 as the coefficients of binary regression equation of the dependent variable front tarsal girth, that is J8=0.152J1+0.771 J7+20.709. One of the common indicators to measure the merits of the equation is the residual analysis. From Figure 1, we can know that the residual distribution is even, and it obeys the normal distribution roughly. Std. Dev (residual standard deviation) is used
14
T. Gong et al.
to reflect the precision of regression equation, its value are the smaller the better, as can be seen from figure 1, the residual standard deviation of front tarsal girth is 0.998 which is so small. Table 5. Regression coefficient d Model
Not coefficient coefficient
1 Constant Ball Girth 2 Constant Ball Girth Length of Foot 3 Constant Ball Girth Length of Foot Width of Foot
standardized coefficient standard error 5.554 0.023 6.511 0.026 0.028
39.98 0.848 20.709 0.771 0.152
Standardized coefficient coefficient
t Value
P Value
0.753 0.138
7.198 37.601 3.181 29.399 5.383
0.0000 0.0000 0.0020 0.0000 0.0000
0.827
30.900 0.771 0.152
8.131 0.026 0.028
0.753 0.139
3.800 29.478 5.427
0.0001 0.0000 0.0000
-0.106
0.051
-0.045
-2.083
0.0380
Note: d Dependent Variable: Front Tarsal Girth.
100
80
y c n eu qe r F
60
40
20
0 -4
-2
0
2
4
6
Mean = 3.35E-15 Std. Dev. = 0.998 N = 654
Regression S tandardized Residual Fig. 1. The histogram of standardized residuals of front tarsal girth
Similarly, with the above method, we can obtain the regression equation of the other details of foot and make the paired samples T test between the actual value and predicted value. We can see the specific results in table 6.
Study on the Establishment of Mathematical Model for Male’s Foot
15
Table 6. Regression model coefficients, correlation coefficient and associated probability Detailed site Ji
The Position of the 1st Metatarsopha langeal Joint J2 The Position of the 5th Metatarsopha langeal Joint J3 The Position of Flank J4 The Position of Heel Heart J5 Front Tarsal Girth J8 The Insidewidth of the 1st Metatarsopha langeal Joint Silhouette J9 The Outsidewidth of the 5th Metatarsopha langeal Joint Silhouette J10 The Outsidewidth of the Flank Silhouette J11 Overall idth of Heel Heart J12
a
b
-0.045
c
0.026
Paired data T test
79.233
r 0.625
Sig. 0.000
t -0.013
Sig. 1.000
0.733
85.465
0.483
0.000
0.023
0.999
1.555
0.993
0.000
-0.045
0.999
19.378
0.615
0.000
-0.089
1.000
20.709
0.836
0.000
-0.002
0.998
0.875
0.876
0.000
-0.084
1.000
0.563
0.931
0.000
0.019
1.000
0.241
0.771
0.013
Correlation inspection
0.965
0.404
0.151
k
0.449
-1.675
0.852
0.000
-0.042
1.000
0.468
15.505
0.609
0.000
-0.064
1.000
16
T. Gong et al. Table 6. (Continued)
The Height of Outer Ankle Downedge J13 The Height of Thumb J14 The Height of Heel Sitedirected J15
0.067
0.074
13.526
0.344
0.000
-0.007
1.000
0.039
0.068
-4.728
0.310
0.000
0
1.000
0.012
0.047
5.629
0.242
0.000
-0.05
0.996
In table 6, index Ji represent detail sizes; a,b,c represent length of foot, ball girth, width of foot respectively, k represents constant. Therefore the equation of foot regression model is: Ji= a×length of foot+b×ball girth+c×width of foot+k. As can be seen from table 6, in the process of correlation inspection, critical confidence level of corresponding parts are less than the critical confidence level 0.05 which are set, it means that we will not accept the original hypothesis, we think that there is significant correlations between the sample values and measured values. There are several parts whose correlation coefficient are more than 0.80 such as the position of flank, front tarsal girth, the inside-width of the 1st Metatarsophalangeal Joint Silhouette ,the outside-width of the 5th Metatarsophalangeal Joint Silhouette and the outside-width of the flank silhouette. It shows that the forecasting effect of regression equation of these parts have achieved a higher level. Paired data T test which research difference between measured and predicted values carries out the single-sample test, even if d = x − x ( i =1,2,…,654), and i
1i
2i
then di was implemented by single-sample T test.T statistic is as follows:
t=
d sd2 n
Among them: the mean of difference variables
(1)
di is d , the variance of margin di
is s 2 , n is the number of samples. d
Table 6 shows the T test results of paired samples between the sample values and predicted values. From the table, we can know critical confidence level of corresponding statistic t is more than the critical confidence level 0.05 which are set, so we will accept the original hypothesis. It means that there is no significant diference between sampled values and predicted values.
4
Conclusions
(1) we establish the mathematical modeling for adult male’s foot shape by using multiple regression theory, its predicted model values are accurate, and the correlation tests are significant, compared to the actual values, the difference is so small.
Study on the Establishment of Mathematical Model for Male’s Foot
17
(2) The mathematical model which is established can estimate the variable of human foot effectively, during 15 variables, in addition to the variables of three basic parts, the correlation coefficient of the remaining 11 variable estimated values and the original values are above 0.75. We can make use of the basic parts of mathematical models to calculate the value of the remaining 11 variables, it not only reduces body measurement site but also greatly reduces the workload measurement. (3) Human foot variable which can not be effectively estimated with the model should use the original variable values in the future’s research. (4) Regression model can be used in shoe design and the production of footwear.
References 1. 2. 3. 4. 5. 6.
Chen, X.M., Zhang, X.: Discuss the Wearing Comfort of Sports Shoes for Young People. J. Textile and Design 3, 103–104 (2005) Li, S.L.: China Shoe Size and the Design of Last. The Light Industry Press, Beijing (1998) Wang, X.X.: Measuring Technology and Methods of the Foot. China’s Individual Protective Equipment 8, 56–72 (2009) Xiong, S.P., Zhao, J.H., Jiang, Z.H.: A Computer-aided Design System for Foot-featurebased Shoe Last Customization. Int. J. Adv. Manuf. Techol. 46, 1–19 (2010) Zhang, W.B., Chen, H.Y.: Statistical Analysis of Practical Data and the Application of SPSS. People’s Posts and Telecommunications Press, Beijing (2006) Li, H., Zhang, X.: The Research on 3d Feature Index Based on the Amount of Feet Shoe. Xian Engineering University of Science and Technology Journal 18, 24–30 (2004)
Strong Law of Large Numbers for Negatively Associated Random Variables Yourong Wang1,*, Yili Tan2, and Yanli Liu3 1
2
Department of Basic, Tangshan College, Hebei Tangshan 063000, China College of Science, Hebei United University, Hebei Tangshan 063009, China 3 Department of Basic, Tangshan College, Hebei Tangshan 063000, China {yourong1214,tanyili_2002}@163.com, [email protected]
Abstract. The classical theorem concerns the arithmetic means which is a regular method of summability. In this paper, under a large class of summability methods, a result for strong law of large numbers for negatively associated random variables is obtained. To investigate this result, this paper establishes a moment inequality for negatively associated random variables. Then, by restricting the moment conditions and use the method of summability, the result is extended for negatively associated random variables, which is closely related to classical theorems. Namely, it links in some sense the strong law of large numbers of Kolmogorov and that of Marcinkiewicz. Keywords: Strong law of large numbers, Negatively associated random variables, Moment condition, Moment inequality.
1 Let
Introduction { X n , n ≥ 1} be a sequence of random variables and let S n = i =1 X i . n
X 1 , X 2 , , X n are said to be negatively associated if for every pair of disjoint subsets A, B of {1,2, n} , Definition 1. The random variables
Cov ( f ( X i , i ∈ A), g ( X j , j ∈ B )) ≤ 0 whenever f and g are coordinate-wise increasing and the covariance exists.[1] Since the definition of negatively associated be presented, some strong law of large numbers has been studied by many authors [2],[3],[4]. In this paper, a large class of summability methods are considered. Definition 2. Let g be a positive increasing function and h a positive function such that φ ( y ) ≡ g ( y ) h( y ) satisfies the following conditions: *
Strong Law of Large Numbers for Negatively Associated Random Variables
(i) for some d ≥ 0 ,
φ
19
is strictly increasing on [ d ,+∞) with range [0,+∞ ) ,
(ii) there exist C and a positive integer k0 such that
φ ( y + 1) / φ ( y ) ≤ C
,
y ≥ k0 , (iii) there exist constants a and b such that
φ ( s) 2
+∞
s
1 dx ≤ as + b , s > d φ ( x) 2
For h and g as above , the (h,g)- transform of sequence
σ n ( x) = If
n
1 1 ξk , g (n) k =1 h(k )
σ n ( x ) → ξ (n → ∞) , then
we say that
{ξ n } is given by
n = 1,2, .
{ξ n } summable (limitable) to ξ
by the
method (h,g), and write ( h, g ) − lim ξ k = ξ . Definition 2 is presented by Ryszard Jajte [5]. It should be stressed here that the above class of sequence transformations includes several summability methods such as arithmetic means [ h ( y ) = 1 ,
g ( y ) = y ] or logarithmic means [ h( y ) = y , g ( y ) = log y ] which also embraces nonregular transformations.
2
Main Result
Theorem. let h and g be as above and let
{X , X n , n ≥ 1}
be a sequence of
negatively associated random variables with identically distribution, let
mk = E[ X k I ( X k ≤ φ ( k ))] if
E[φ −1 ( X )] < ∞
(1)
then
(h, g ) − lim( X k − mk ) = 0 a.s. To prove the theorem , first to give the following lemmas. Lemma 1. let {bn , n ≥ 1} be a nondecreasing, unbounded sequence of positive numbers. Let
{α n , n ≥ 1} be nonnegative sequence, let r be a fixed positive number.
Assume that for each n ≥ 1 , n
E (max Si ) r ≤ α i , 1≤ i ≤ n
n
if
αi
b i =1
i
< ∞ , then
i =1
20
Y. Wang, Y. Tan, and Y. Liu
Sn =0 n→∞ b n
lim
a.s.
n →∞.
Some inequalities for negatively associated random variables are already discussed such as [6],[7],[8],[9]. Here, a new inequality for negatively associated random variables is obtained. Lemma 2. let {X n , n ≥ 1} be a sequence of negatively associated random variables with finite fourth moments and zero means. Then, for every n
n
E (max Si )4 ≤ 24 ( EX i + 6 EX i 1≤ i ≤ n
i =1
4
i=2
2
ε >0,
i −1
EX
2 j
).
j =1
Proof. Since
max( S1 , S 2 , , S n ) ≤ max(0, S1 , S 2 , , S n ) + max(0,− S1 ,− S 2 , ,− S n ) So that
{
}
E (max Si ) 4 ≤ 23 E[max(S1 , S 2 , , S n )]4 + E[max(0,− S1 ,− S 2 , ,− S n )]4 . 1≤i ≤n
Let
M n = max(S1 ,, S n ) = X 1 + max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n ) It is obviously that
X 1 and max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n ) are
negatively associated. thus
EM n = EX 1 + 4 E[ X 1 max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n )] 4
4
3
+ 6 E{ X 1 [max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n )]2 } 2
+ 4 E{ X 1[max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n )]3} + E[max(0, X 2 , X 2 + X 3 ,, X 2 + X 3 + X n )]4
≤ EX 1 + 4 EX 1 E[max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n )] 4
3
+ 6 EX 1 E[max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n )]2 2
+ 4 EX 1 E[max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n )]3 + E[max(0, X 2 , X 2 + X 3 ,, X 2 + X 3 + X n )]4
≤ EX 1 + 6 EX 1 E[max(0, X 2 , X 2 + X 3 , , X 2 + X 3 + X n )]2 4
2
+ E[max(0, X 2 , X 2 + X 3 ,, X 2 + X 3 + X n )]4
≤ EX 1 + 6 EX 1 E[ X 2 + max(0, X 3 , X 3 + X 4 , , X 3 + X 4 + X n )]2 4
2
Strong Law of Large Numbers for Negatively Associated Random Variables
21
+ E[ X 2 + max(0, X 3 , X 3 + X 4 , , X 3 + X 4 + X n )]4
≤ EX 1 + 6 EX 1 {EX 2 + E[max( X 3 , X 3 + X 4 , , X 3 + X 4 + X n )]2 } 4
2
2
+ EX 2 + 6 EX 2 E[max( X 3 , X 3 + X 4 ,, X 3 + X 4 + X n )]2 4
2
+ E[max( X 3 , X 3 + X 4 , , X 3 + X 4 + X n )]4 then by induction,
EM n ≤ 4
n
( EX
4 i
+ 6 EX i
2
i =1 n
i −1
EX
2 j
)
j =i +1 n
= EX i + 6 EX i 4
i =1
2
i =2
i −1
EX j =1
2 j
X n ’s by − X n ’s, it is Suitable for E[max(0,− S1 ,− S 2 , ,− S n )]4 .
Replacing
And taking into account inequality, the result is obtained. In the further consideration to prove the theorem we also need the following concept of the equivalence in the sense of Khinchin [10].
{
}
Definition 3. The sequences {X n , n ≥ 1} and X n , n ≥ 1 are said to be equivalent ∞
in the sense of Khinchin, if
P[ X n =1
{
n
*
≠ X n* ] < ∞ .
} be two sequences of random variables
Lemma 3. Let {X n , n ≥ 1} and X n , n ≥ 1 *
equivalent in the sense of Khinchin, and let {an , n ≥ 1} be a sequence of real numbers. If
1 n X i − an → 0 a.s. n → ∞ n i=1 Then
1 n * X i − an → 0 a.s. n → ∞ . n i =1 Proof of Theorem. Let
X n′ = X n I ( X n ≤ φ (n)) , Yn = X n′ − EX n′ ,
n
n Xk Y , S n′ = k k =1 h ( k ) k =1 h( k )
Sn =
By definition 2, it is enough to show that
1 n X k − mk → 0 a.s. n → ∞ g ( n) k =1 h( k )
22
Y. Wang, Y. Tan, and Y. Liu
Since ∞
P[ n =1
∞ X n′ X ≠ n ] = P[ X n ≥ φ (n)] h( n ) h( n) n =1
∞
= P[φ −1 ( X n ) ≥ n] n=1
≤ E[φ −1 ( X )] < ∞ X′ Xn , n ≥ 1 and n , n ≥ 1 are equivalent in the sense of h(n) h(n)
By definition 3,
Khinchin. Thus by lemma 3, we only need to prove
1 n X k′ − mk → 0 a.s. n → ∞ g ( n) k =1 h( k ) That is
Note that
S′ 1 n Yk = n → 0 a.s. n → ∞ g (n) k =1 h(k ) g (n)
(2)
Xk , k ≥ 1 is a sequence of negatively associated random variables. h(k )
By lemma 2, n
E (max Si′ ) 4 ≤ 24 [ E 1≤i≤ n
i =1
4 2 n X′ X i′ X i′ i−1 + 6 E E 2j ] 4 2 h (i ) h (i) j =1 h ( j ) i =2 2
4 4 2 n X 1′i X i′ X i′ i −1 X ′j ≤ 2 {6[ E 4 + ( E 4 + E 2 E 2 )]} h (1) i = 2 h (i ) h (i ) j =1 h ( j ) 2
4
By lemma 1, just need to prove ∞
g n =1
1 X′ E 4n <∞ (n) h (n)
4
(3)
and
X ′j 2 1 X n′ 2 n−1 <∞ E E 4 h 2 ( n) j =1 h 2 ( j ) n = 2 g ( n) ∞
First to prove (3). ∞
g n =1
∞ 1 1 X n′ = EX n′4 E 4 4 4 ( n) h ( n) n=1 φ (n)
(4)
Strong Law of Large Numbers for Negatively Associated Random Variables
23
E[ X n4 I ( X n ≤ φ (n))] = φ 4 ( n) n =1 ∞
E[ X n2φ 2 (n) I ( X n ≤ φ (n))] ≤ φ 4 (n) n =1 ∞
E[ X n2 I ( X n ≤ φ (n))] = φ 2 ( n) n =1 ∞
E[ X 2 I ( X ≤ φ (n)) = φ 2 (n) n =1 ∞
X 2 I ( X ≤ φ ( n) ≤ E φ 2 ( n) n =1 ∞
Since
X = φ (φ −1 ( X )) , by (ii),(iii), there exist C and k0 > 0 , such that
φ ( y + 1) φ ( y ) ≤ C , y > k0 , then ∞ X 2 I ( X ≤ φ (k ) X 2 I ( X ≤ φ ( n) 2 ≤ k0 + C φ 2 (n) φ 2 (k ) n =1 k =k0 +1 ∞
∞
1 dx φ (X ) ≤ k0 + C 2 aφ −1 ( X ) + C 2b
≤ k0 + C 2 X 2 −1
φ (X )
2
By (1), ∞
E n =1
X 2 I ( X ≤ φ ( n) <∞ φ 2 ( n)
(5)
EX n′4 < ∞ , (3) is proved. 4 n =1 g ( n) ∞
So
Next to prove (4), 2 2 ∞ 1 EX n′2 n−1 EX ′j X n′2 n−1 X ′j ≤ E 2 E 2 4 h (n) j =1 h ( j ) n=2 φ 2 (n) j =1 φ 2 ( j ) n =2 g ( n ) ∞
2 EX n′2 ∞ EX ′j ≤ 2 2 n = 2 φ ( n) j =1 φ ( j ) ∞
∞ EX n′2 ≤ 2 n=1 φ ( n)
2
24
Y. Wang, Y. Tan, and Y. Liu
∞ X 2 I ( X ≤ φ ( n)) ≤ E φ 2 (n) n=1
2
Hence the result (4) follows by (5). The theorem is proved. Remarks. (1) It is clear that the theorem essentially gives the classical result of Marcinkiewicz [ for φ ( x) = x ] or that of Kolmogorov [ for h(n)=1, g(n)=n]. (2) Our theorem seems to be also for a particular case of logarithmic means 1/ α
1 n 1 ( X k − mk ) , log n k =1 k That is for φ ( x ) = x log x . (3) It is also worth noting that in the case α
E ( X ) ≤ E (ϕ −1 ( X )) ≤ E ( X ) , for 0 < α < 1 , Thus, the moment conditions is situated between that of Marcinkiewicz and Kolmogorov.
References 1. Joag-Dev, K., Proschan, F.: Negative association of random variables with applications. Ann. Statistic. 11, 286–295 (1983) 2. Liu, L., Sheng, S.: On Sufficient and Necessary Condition of a Strong Law of Large Numbers for Negatively Associated Random Variables. Chinese Journal of Applied Probability and Statistics 24(4) (2008) 3. Zhou, S.-n., Ming, R.-x., Huang, L.: Complete Convergence for Randomly Weighted Sums of Negatively Associated Random Variables. Journal of Jiangxi Normal University(natural sciences edition) 33(6) (2009) 4. Liang, H., Zhang, J.: Strong Convergence for Weighted Sums of Negatively Associated Arrays. Chinese Annals of Mathematics, Series B 31(2) (2010) 5. Jajte, R.: On the strong law of large numbers. Ann. Probab. 31(01), 409–412 (2003) 6. Kuczmaszewska, A.: The strong law large numbers for dependent random variables. Statis. Probab. Lett. 73, 305–314 (2005) 7. Xing, G., Yang, S.: Exponential Inequalities for Negatively Associated Random Variables. Acta Mathematica Scientia 29(6) (2009) 8. Christofides, T.C., Hadjikyriakou, M.: Exponential inequalities for N-demimartingales and negatively associated random variables. Statistics & Probability Letters 79(19) (2009) 9. Xing, G.D.: On the exponential inequalities for strictly stationary and negatively associated random variables. Journal of Statistical Planning and Inference 139(10) (2009) 10. Révész, P.: The Laws of Large Numbers. Academic Press (1968)
Schur-Convexity of Generalized Heronian Mean Tian-yu Zhang and Ai-ping Ji College of Mathematics, Inner Mongolia University for Nationalities, Tongliao, 028043 Inner Mongolia China {Tian-yu Zhang,zhangtianyu7010}@126.com
Abstract. In this paper, the generalized Heronian mean of n -tuple positive real valued function was defined which was the extension of the generalized Heronian mean of n -tuple positive real variable. By so-called Schur's condition, the Schur-convexity and Schur-geometric convexity and Schur-harmonic convexity are studied for the generalized Heronian mean of n -tuple positive real valued function, and derive some results. Then the Schur-convexity also was discussed for its quotient, and as applications, a inequality is derived. Keywords: Generalized Heronian Mean, Schur-convex, Schur-geometric convex, Schur-harmonic convex, Symmetric function.
1
Introduction
Throughout this paper, let
，
{
}
R+ = (0, +∞) R+n = x = ( x1 , x2 , , xn ) xi ∈ R+n , i = 1, 2, n . For Ω ⊆ R+n , set ln Ω = {(ln x1 , ln x2 , , ln xn ) x = ( x1 , x2 , , xn ) ∈ Ω} ,
for a, b ∈ R+ . W. Janous improved Heronian mean H e (a, b) , defined the Generalized Heronian mean H e (a, b) as follows[3]:
a + ω ab + b , 0 ≤ ω < ∞, H ω ( a, b) = ω+2 ω = ∞. ab ,
(2)
and discussed the comparability between power mean, exponential mean, logarithmic mean and Heronian mean. The Generalized Heronian mean H1, p (a, b) is as p a p + (ab) 2 + b p H1, p (a, b) = 3 ab ,
1
p ,
p ∈ R , p ≠ 0,
(3)
p = 0,
and the monotony and Schur-convex of H1, p (a, b) was studied on ( a, b) in [6]. Then, some properties for H1, p (a, b) was discussed in [5-13]. In [14], the general type of the Generalized Heronian mean (3) is defined as p a p + ω (ab) 2 + b p H ω , p ( a, b) = ω +2 ab ,
1
p , p ∈ R, p ≠ 0, ω ∈ R , 0
(4)
p = 0, or ω = +∞.
and Schur-convex of H ω , p (a, b) is discussed. In[15], the Generalized Heronian mean Hω ( x1 , x2 , xn ) for n -tuple of the Generalized Heronian mean (2) was introduced by Guan as nAn ( x) + ω Gn ( x) , 0 ≤ ω < ∞, H ω ( x) = H ω ( x1 , x2 , xn ) = x ∈ R+n . (5) ω+n G ( x), ω = ∞ . n and the Schur-convexity of Hω ( x1 , x2 , xn ) was discussed. Now, we further improved Generalized Heronian mean H ω ( x1 , x2 , xn ) as follows: nAn ( f ( x)) + ω Gn ( f ( x)) , 0 ≤ ω < +∞, H n,ω ( x; f ) = n +ω G ( f ( x)), ω = +∞. n
(6)
Schur-Convexity of Generalized Heronian Mean
27
The purpose of this paper is discussing Schur-convexity and Schur-geometric convexity and Schur-harmonic convexity of H n ,ω ( x; f ) .
2
Conceptions and Lemmas
In order to prove our main results, we introduce several concepts and lemmas, which we present in this section. Definition 2.1[4,17-21]. Let x = ( x1 , x2 , , xn ), y = ( y1, y2 , , yn ) ∈ R n . x is said to be
majorized by y (in symbols x y ) if k
k
i =1
i =1
x[i ] ≤ y[i ] , k = 1, 2, , n − 1 ,and
n
n
i =1
i =1
x[i ] = y[i ] ,
where x[1] ≥ x[2] ≥ ≥ x[ n ] ,and y[1] ≥ y[2] ≥ ≥ y[ n ] are rearrangements of and in descending order. Definition 2.2[4,17-21]. Let Ω ⊂ R n be a symmetric convex set. A real-valued function ϕ: Ω → R is said to be Schur-convex on Ω if
ϕ ( x) ≤ ϕ ( y ) for all x, y ∈ Ω and x y . ϕ is said to be Schur-concave on Ω if −ϕ is Schur-convex. Definition 2.3[4,17-21]. Let Ω ⊆ R+n be a symmetric geometric convex set. The
function ϕ is said to be Schur-geometrically convex on Ω if the function ϕ (e x ) is Schur-convex on ln Ω . ϕ is said to be Schur-geometrically concave on Ω if −ϕ is Schur-geometrically convex. Definition 2.4[4,17-21]. Let Ω ⊆ R+n be a symmetric harmonic convex set. The func-
tion ϕ is said to be Schur-harmonic convex on Ω if the function φ (1 x ) is Schurconvex on
1 Ω
. ϕ is said to be Schur-harmonic concave on Ω if −ϕ is Schur-harmonic
convex. Lemma 1[16]. Let I ⊂ R+ is a interval, and f : x → R+ is a positive real-valued function.
(1) f is called GA - convex function if f is GG - convex function on I . (2) f is called HG - convex function if f is HH - convex function on I , and f is called HA - convex function if f is HG - convex function on I . The above implication relations are reverse for the concavity. Lemma 2. Let I ⊂ R+ is a interval. If f : x → R+ is a differentiable and logarithmic convex function, then f ′( x) and f ′( x) f ( x) are increasing on I . If f : x → R+ is a
28
T.-y. Zhang and A.-p. Ji
differentiable and logarithmic concave function, then f ′( x) and f ′( x) f ( x) are decreasing on I . Lemma 3[16]. Let I ⊂ R+ is a interval, and f : x → R+ is a positive real-valued function, then the following propositions are equivalent.
(1) f is GA - convex ( GA - concave) function on I . (2) f (e x ) is convex (concave) function on ln I . (3) xf ′( x) is increasing(decreasing) on I . Lemma 4[16]. Let I ⊂ R+ is a interval, and f : x → R+ is a positive real-valued function, then the following propositions are equivalent.
(1) f is HA - convex ( HA - concave) function on I . (2) f (1 x) is convex (concave) function on 1 I . (3) x 2 f ′( x) is increasing (decreasing) on I . Lemma 5. Let I ⊂ R+ is a interval, and f : x → R+ is a positive real-valued function, then the following propositions are equivalent.
(1) f is GG - convex ( GG - concave) function on I . (2) ln f (e x ) is convex (concave) function on ln I . (3) x 2 f ′( x) is increasing (decreasing) on I . The following so-called Schur’s condition is very useful for determining whether or not a given function is Schur-convex or concave. Lemma 6(Schur-Ostrowski Theorem)[5,6]. Let Ω ⊂ R n be a symmetric convex set with nonempty interior, and φ : Ω → R be a continuous symmetric function on Ω .If
φ is differentiable in ΩD , then φ is Schur-convex( concave) on Ω if and only if ∂φ ∂φ − ( x1 − x2 ) ≥ 0(≤ 0), ∂x1 ∂x2 for all x ∈ ΩD . Lemma 7[15]. Let xi ≥ 0 , i = 1, 2, , n,
n
x i=
i
= s, and c ≥ s, then
c−x c − s c − x1 c − x2 = nc , nc , , nc n , ( x1 , x2 , , xn ) = x. nc s −1 s −1 s −1 s −1
3
Main Results
In this section, we discuss the Schur-convexity and the Schur-geometric convexity and the Schur-harmonic convexity of H n,ω ( x; f ) , our main results are the following.
Schur-Convexity of Generalized Heronian Mean
29
Theorem 1. Let I ⊂ R+ is a interval, and f : x → R+ is a positive real-valued function.
(1) If f ( x) is a differentiable and logarithmic convex function on I , then H n ,ω ( x; f ) is Schur-convex function on I n . (2)If f ( x) is a differentiable and logarithmic concave function on I , then H n ,ω ( x; f ) is Schur-concave function on I n . Proof. (1) For
∂H n ,ω ( x; f ) ∂xi
f ′( xi )(nf ( xi ) + ωGn ( f ( x))) , i = 1, 2 , n(n + ω ) f ( xi )
=
then
∂H ∂H ( x1 − x2 ) − ∂x1 ∂x2 (x − x ) ( x − x )( f ( x2 ) f ′( x1 ) − f ( x1 ) f ′( x2 )) = 1 2 ( f ( x1 ) − f ( x2 )) + 1 2 Gn ( f ( x)), (n + ω ) n( n + ω ) f ( x1 ) f ( x2 ) According to Lemma 2, we have
∂H ∂H − ( x1 − x2 ) ∂x1 ∂x2
≥ 0,
So H n ,ω ( x; f ) is Schur-convex function on I n by Lemma7. (2) Similarly, H n,ω ( x; f ) is Schur-concave function on I n . Thus the proof of Theorem 1 is complete. Theorem 2. Let I ⊂ R+ is a interval, and f : x → R+ is a positive real-valued function. (1) If f ( x) is a GG convex function on I , then H n,ω ( x; f ) is Schur-geometric con-
vex function on I n . (2) If f ( x) is a GA concave function on I , then H n,ω ( x; f ) is Schur-geometric concave function on I n . Proof. (1) According to Definition1.4, we only need to prove that
nAn ( f (e x )) + ωGn ( f (e x )) 0 ≤ ω < ∞, H n,ω (e ; f ) = ω+n G ( f (e x )) , ω = ∞. n x
is Schur-convex function on ln( I n ) = (ln I ) n .
30
T.-y. Zhang and A.-p. Ji
For ∂H n,ω (e xi ; f ) ∂xi
=
e xi f ′(e xi )( nf (e xi ) + ω Gn ( f (e x ))) , i = 1, 2, , n, n( n + ω ) f (e xi )
then ( x1 − x2 )( =
∂H n ,ω (e x , f ) ∂x1
−
∂H n ,ω (e x , f ) ∂x2
)
( x1 − x2 ) (nf (e x1 ) f (e x2 )(e x1 f ′(e x1 ) − e x2 f ′(e x2 )) n(n + ω ) f (e x1 ) f (e x2 ) + ωGn ( f (e x ))(e x1 f (e x2 ) f ′(e x1 ) − e x2 f (e x1 ) f ′(e x2 )).
According to Lemma1 , Lemma 3 and Lemma 5, we have ( x1 − x2 )(e x1 f ′(e x1 ) − e x2 f ′(e x2 )) ≥ 0, ( x1 − x2 )(e x1 f ′(e x1 ) f (e x2 ) − e x2 f ′(e x2 ) f (e x1 )) ≥ 0, By Lemma 6, H ωn (e x ; f ) is Schur-convex function on ln( I n ) = (ln I ) n , and so H ωn ( x; f ) is Schur-geometric convex function on I n . (2) According to Lemma 3 and Lemma5, we have ( x1 − x2 )(e x1 f ′(e x1 ) − e x2 f ′(e x2 )) ≤ 0, ( x1 − x2 )(e x1 f ′(e x1 ) f (e x2 ) − e x2 f ′(e x2 ) f (e x1 )) ≤ 0, By Lemma 6, H ωn (e x ; f ) is Schur-concave function on ln( I n ) = (ln I ) n , and so H ωn ( x; f ) is Schur-geometric concave function on I n . Thus the proof of Theorem 2 is complete. Theorem 3. Let I ⊂ R+ is a interval, and f : x → R+ is a positive real-valued function.
(1) If f ( x) is a HG convex function on I , then H n,ω ( x; f ) is Schur-harmonic convex function on I n . (2) If f ( x) is a HA concave function on I , then H n,ω ( x; f ) is Schur-harmonic concave function on I n . Proof. (1) According to Definition1.5, we only need to prove that
nAn ( f (1 x)) + ω Gn ( f (1 x)) , 0 ≤ ω < ∞, H n ,ω (1 x ; f ) = ω+n ω = ∞. Gn ( f (1 x )) , is Schur-convex function on 1 I n = (1 I ) . n
Schur-Convexity of Generalized Heronian Mean
31
For
∂H n,ω (1 x ; f ∂xi
)
=
) ( nf (1 x ) + ωG ( f (1 x)) ) , i = 1, 2, , n, n(n + ω ) f (1 x )
− 1 xi2 f ′ (1 xi
i
n
i
then ∂H ∂H ( x1 − x2 ) − ∂x1 ∂x2 −( x1 − x2 ) = (1 x1 f ′ (1 x1 ) − 1 x2 f ′ (1 x2 ) ) (n + ω ) −( x1 − x2 )ωGn ( f (1 x)) + (1 x12 f (1 x2 ) f ′ (1 x1 ) − 1 x22 f (1 x1 ) f ′ (1 x2 ) ) . n( n + ω ) f (1 x1 ) f (1 x2 ) According to Lemma1, and Lemma 4, we have −( x1 − x2 ) (1 x1 f ′ (1 x1 ) − 1 x2 f ′ (1 x2 ) ) ≥ 0,
−( x1 − x2 ) (1 x12 f (1 x2 ) f ′ (1 x1 ) − 1 x22 f (1 x1 ) f ′ (1 x2 ) ) ≥ 0, By Lemma 6, H n,ω (1 x ; f ) is Schur-convex function on 1 I n = (1 I ) , and so n
H n,ω ( x; f ) is Schur-harmonic convex function on I n . (2) According to Lemma1, and Lemma 4, we have −( x1 − x2 ) (1 x1 f ′ (1 x1 ) − 1 x2 f ′ (1 x2 ) ) ≤ 0,
−( x1 − x2 ) (1 x12 f (1 x2 ) f ′ (1 x1 ) − 1 x22 f (1 x1 ) f ′ (1 x2 ) ) ≤ 0,
By Lemma 6, H n,ω (1 x ; f ) is Schur-concave function on 1 I n = (1 I ) , and so n
H n,ω ( x; f ) is Schur-harmonic concave function on I n . Thus the proof of Theorem 3 is complete.
（ ）
Theorem 4. Let I ⊂ R is a interval, and f : x → R+ ω ≥ 1 is a positive real-valued function. If f ( x) is a differentiable convex function, also is a logarithmic concave
function on I , then H n,ω ( x; f ) H n,ω -1 ( x; f ) is Schur-concave function on I n . Proof. Let ϕ ( x ) = H n ,ω ( x; f ) H n ,ω -1 ( x; f ) . For
∂ϕ Gn ( f ( x)) f ′( xi )( An ( f ( x)) − f ( xi )) = , ∂xi (n + ω )(n + ω − 1) H n2,ω −1 ( x; f ) f ( xi ) then ∂ϕ ∂ϕ Gn ( f ( x ))( x1 − x2 ) − ( x1 − x2 ) = 2 ∂x1 ∂x2 (n + ω )(n + ω − 1) H n ,ω −1 ( x; f ) An ( f ( x)) ( ( f ′( x1 ) f ( x1 ) − f ′( x2 ) f ( x2 ) ) − ( f ′( x1 ) − f ′( x2 )) ) .
32
T.-y. Zhang and A.-p. Ji
By f ( x) is a differentiable convex function, also is a logarithmic concave function on I , we have ( x1 − x2 ) ( f ′( x1 ) f ( x1 ) − f ′( x2 ) f ( x2 ) ) ≤ 0, ( x1 − x2 )( f ′( x1 ) − f ′( x2 )) ≥ 0, By lemma 6, H n,ω ( x; f ) H n,ω -1 ( x; f ) is Schur-concave function on I n . Corollary 5. Let I ⊂ R is a interval, and f : x → R+ is a positive real-valued func-
tion. If f ( x) is a differentiable convex function, also is a logarithmic concave function on I , then H n ,ω ( x , f ) H n ,ω (1 − x, f )
≤
H n ,ω −1 ( x, f ) H n ,ω −1 (1 − x, f )
,
n
for
f ( x ) = 1, and ω ≥ 1 . i=
i
Proof. By lemma 7, we have
c − f ( xn ) c − f ( x1 ) c − f ( x2 ) n − 1 , n − 1 , , n − 1 , ( f ( x1 ), f ( x2 ), , f ( xn )). then by lemma 4, we complete the proof of Corollary 5.
References 1. Alzer, H., Janous, W.: Solution of Problem 8*. Crux. Math. 13, 173–178 (1987) 2. Bullen, P.S., Mitrinvić, D.S., Vasić, P.M.: Means and Their Inequalities. Kluwer Academic Publishers, Dordrecht (1988) 3. Janous, W.: A Note on Generalized Heronian Means. Math. Inequal. Appl. 4, 369–375 (2001) 4. Shi, H.-N., Jiang, Y.-M., Jiang, W.-D.: Schur-Convexity and Schur-Geometrically Con-cavity of Gini Mean. Comput. Math. Appl. 57, 266–274 (2009) 5. Guan, K.-Z., Zhu, H.T.: The Generalized Heronian Mean and Its Inequalities. Univ. Beograd, Publ. Elektrotehn. Fak. Ser. Mat. 17, 60–75 (2006) 6. Jia, G., Cao, J.: A New Upper Bound of the Logarithmic Mean. J. Inequal. Pure Appl. Math. 4(4) Art. 80 (2003) 7. Liu, Z.: Comparison of Some Means. J. Math. Res. Exp. 22(40), 583–588 (2002) 8. Yang, Z.-H.: ON the Homogeneous Functions With Two Parameters and Its Monotonicity. J. Inequal. Pure Appl. Math. 6(4) Art. 101 (2005) 9. Yang, Z.-H.: ON the Log-convexity of Two-parameter Homogeneous Functions. Math. Inequal. Appl. 10(3), 499–516 (2007) 10. Yang, Z.-H.: On the Monotonicity and Log-convexity of a Four-parameter Homogeneous Mean. J. Inequal. Appl. Art. ID 149286, 12 pages (2008) 11. Yang, Z.-H.: Some Monotonictiy Results for the Ratio of Two-parameter Symmetric Homogeneous Functions. Int. J. Math. Math. Sci. Art. ID 591382, 12 pages (2009)
Schur-Convexity of Generalized Heronian Mean
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12. Zhang, Z.-H., Wu, Y.-D.: The Generalized Heron Mean and Its Dual Form. Appl. Math. E-Notes 5, 16–23 (2005) 13. Zhang, Z.-H., Wu, Y.-D.: The Properties of the Generalized Heron Means and Its Dual Form. RGMIA Res. Rep. Col l. 7(2) Art. 1 (2004) 14. Shi, H.-N., Bencze, M., Wu, S.-H., Li, D.-M.: Schur-Convexity of Generalized Heronian Means Involving Two Parameters. Journal of Inequalities and Applications, Article ID 879273, 9 page (2008) 15. Guan, K.-z.: Schur-Convexity of Generalized Heron means. Journal of Heng Yang Normal University 6, 1–3 (2006) 16. Guan, K.-z.: Some Properties of a Generalized Hamy Symmetric Function and Its Applications. J. Math. Anal. 376, 494–505 (2011) 17. Wang, B.-Y.: Foundations of Majorization Inequalities. Beijing Normal Univ. Press, Beijing (1990) 18. Marshall, A.M., Olkin, I.: Inequalities: Theory of Majorization and Its Application. Academies Press, New York (1979) 19. Zhang, X.-M.: Schur-Convex Functions and Isoperimetric Inequalities. Proc. Amer. Math. Soc. 2, 461–470 (1998) 20. Xia, W.-F., Chu, Y.-M.: Schur-Convexity for a Class of Symmetric Functions and Its Applications. Journal of Inequalities and Applications, Article ID 493759, 15 pages (2009) 21. Shi, H.-N.: Schur-Geometric Convexity for Differences of Means. Applied Mathematics E-Notes 10, 275–284 (2010)
Design of Virtual Oscilloscope Based LabVIEW Dong ShengLi1, Han JunFeng2, Pan ShengHui1, and Deng JianFeng3 2
1 Guangxi university of technology, LiuZhou, 545006 Guangxi college of electromechanical vocational, NanNing, 530117 3 GuiLin University of electronic technology, GuiLin, 541004 [email protected], [email protected]
Abstract. The virtual instrument is the main content of instrument technology nowadays. This article details the implementation process of the virtual oscilloscope. It is designed by LabVIEW graphical programming language. The virtual oscilloscope can achieve waveform display, channel selection, data collection, data reading, writing and storage, spectrum analysis, printing and waveform parameters measurement. It also has a friendly user interface and can be operated conveniently. Keywords: Oscilloscope, Virtual instrument, Data acquisition, LabVIEW.
1
Introduction
In recent years, with the rapid development of computer technology, virtual instrument technology in data acquisition, automated test and measurement instrumentation is widely used to promote and facilitate the testing system and measuring equipment design and implementation of technology. "Software is the instrument" becomes a test and measurement technology important symbol. This development platform LabVIEW virtual instrument developed a virtual oscilloscope, not only reduces the price of the instrument, but also extends the scope of the analysis and computing capacity, and enhance the versatility of the instrument [1].
The overall structure of the virtual oscilloscope shown in Fig.1, mainly by the data acquisition card, communication interface and user interface components and virtual instruments. Data collection card is mainly responsible for acquiring the signals which are controlled by the MCU after the analog to digital conversion and read, at the same time, the read data by the USB communication interface are transferred into the computer. However, the user interface of virtual instrument mainly completes receiving and processing SCM signals to display on the instrument panel, in order to achieve the system's instruments measure function. 2.2
Data Acquisition Card
However considering real-time, economy and flexibility, the system of uses EZ-USBFX2 series USB controller to design data acquisition card. To CY7C68013 singlechip as control core of data acquisition system, including signal regulate circuit and single-chip microcomputer peripheral circuit, USB peripheral circuit 4 most, mainly accomplish the field signal collection, transformation and read, then And the data to read from the USB communication interface into a computer. 2.3
Functional Design of Virtual Digital Oscilloscope
The design of virtual oscilloscope refers to the function of traditional oscilloscope, and combines with the characteristics of virtual instrument and computer powerful information processing capability, expand on the function to realize the waveform display, storage and the time domain and frequency domain parameters of automatic measurement as well as display and inquires. Virtual oscilloscope function such as main technical indices: Sampling rate: 100kb / s; Sampling accuracy: 0.390625%; Waveform Display Mode: double channel A, B; Data Storage: hard drive, U disk.
3
Instrument Software Design
3.1
Virtual Oscilloscope Development Tools
Virtual oscilloscope software design using the virtual instrument development tools LabVIEW of NI Company. Using of LabVIEW virtual instrument development platform programs which is VI includes three parts: program the front panel, block diagram and icon/connector. Program the front panel used to set the input value and observing output, and generate imitation of traditional instrument control panel [2], every program is corresponding to the front panel for a block diagram. With the LabVIEW graphical block diagram programming language, similar to the traditional program's source code. Icon/connector is subroutines SubVI is other VI invoked the interface.
36
3.2
D. ShengLi et al.
Software Design of Virtual Oscilloscope
Modular software design with the preparation, implementation of each functional module consists of a complete system software generally, including data acquisition, waveform display, spectrum analysis, waveform data read and write and save and print waveforms such as modules, and ultimately Data acquisition, processing, recording and display functions. 3.3
Oscilloscope Front Panel Design
Virtual oscilloscope control and display function all through the front panel object to realize, design the front panel is note should both comply with the style of traditional instruments, and to use habit, the advantages of LabVIEW platform of double channel the front panel of virtual oscilloscope is shown in fig.2.
Fig. 2. Dual-channel virtual oscilloscope front panel
Soft panel programs provide interface which is between the user and a virtual oscilloscope .Users could use switch buttons of the soft panel to simulate the operation of traditional instruments, and then through keyboard and mouse control of the virtual oscilloscope. When the users press the "collection" button and then run the programs, so signals could be collected. Users could undertake single channel and double channel arbitrary switching; various functions on the panel of the module of buttons, there should be a corresponding press this button can mix this module subroutines. Pressing return or close button on sub module interface, users can go back to the main program interface. 3.4
The Main Modules
3.4.1 Signal Acquisition Module Data acquisition module is the core of the virtual oscilloscope software, mainly to complete data collection, including trigger control, access control and time base
Design of Virtual Oscilloscope Based LabVIEW
37
control. Trigger control mainly control that a channel measurement analysis; the time base control main control acquisition card scanning rate, each channel acquisition sample number. LabVIEW does not own EZ-USBFX2 Series USB controller driver used in the program box NI VISA in LabVIEW module design, implementation, and communication interface on the USB configuration [4]. Configuration of the steps: NI VISA
① ② ③
Using Driver Development Wizard (Driver Development Wizard) to create INF document; INF installation document and the USB device based on the INF document; Using NI VISA Interactive Control (NI VISA Interactive Control tool) to test the equipment to confirm that USB device is properly installed, and access USB devices in the property value. After completing the configuration, again carries on the combined with VI VISA ViOpen, ViProperty LabVIEW templates ViWrite, ViClose ViRead, and all nodes to set can complete the communication interface device configuration USB. Then set LabVIEW with NI VISA matching template ViOpen, ViProperty, ViWrite, ViRead, ViClose set various nodes on the USB interface device to complete the communication configuration.
Fig. 3. Acquisition block diagram
38
D. ShengLi et al.
Acquisition module part of the block diagram as follows Fig.3. Passage of A and B can directly acquisition USB interface transmission of data can also be collecting system since fitting data. 3.4.2 Oscilloscope Display Module The main channel through the control panel, select the button "A", "B" and A & B, you can display any one channel or dual channel signal waveform. 3.4.3 Spectrum Analysis Module The signals of collection selection of spectral analysis, Windows have HanMing window, flat-roofed window, HaNing Windows, etc 9 kinds. Log / Linear choose to provide two kinds of coordinate display mode. Display unit provides 8 units selected, this option can be controlled through the main panel. Spectral analysis front panel shows in Fig.4.
Fig. 4. Spectrum analysis the front panel
3.4.4 Measuring the Parameters of the Waveform Data Module When you press the main panel on the "measure" button, adjusting the parameters of routine measurement of the panel, the module can measure many parameters and display, AC voltage, DC voltage, RMS voltage, sampling frequency, sampling period, accounting for Air ratio, positive pulse, negative pulse width, rise time, fall time, average voltage, maximum voltage, maximum voltage, low voltage, differential pressure, peak voltage and so on. Front panel of the waveform data parameters measured as shown in Fig.5.
Design of Virtual Oscilloscope Based LabVIEW
39
Fig. 5. Measurement waveforms parameters the front panel
3.4.5 Waveform Storage and Read-Write Module Users press Lord panel "write dish" button to collect data and then saved the data, when pressing "read dish" buttons at same time users could read the preservation of the data. The data can be read automatically displayed on parameter measurement and waveform.
4
Experimental Results
Design test signals from YB1602 type selection signal generator (2Hz~2Mz), the simultaneous determination YB43020 oscilloscope input signal frequency and amplitude, were compared. Compare with the measurements of frequency and amplitude between Virtual oscilloscope and traditional oscilloscope such as shown in table1. Table 1. Virtual oscilloscope measurement range and contrast of traditional oscilloscope
Oscilloscope type Traditional oscilloscope Virtual oscilloscope
Frequency(kH z) Min Max 0.02 21 0.1 100
Width (V) Min Max 0.001 20.0 0.001 5.0
Fig.5 is a voltage of 1.5V, a frequency of 10Hz sine wave signal to the oscilloscope display. Fig.6 is a sine wave voltage and time parameter measurement results.
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Fig. 6. Voltage of 1.5V, a frequency of 10Hz sinusoidal waveform
Fig. 7. Sine wave of voltage and time parameter measurement results
The results show that in the LabVIEW graphical programming language environment to achieve a convenient, flexible and virtual oscilloscope.
5
Conclusions
This paper designs a virtual oscilloscope waveform of the automatic measurement, analysis, processing, saving time and increasing accuracy of measurement of
Design of Virtual Oscilloscope Based LabVIEW
41
parameters to achieve the waveform data storage and display, with waveform filtering and display. Virtual oscilloscope waveform simulation, and pause the instrument using for the advantage. The practical application showed the virtual oscilloscope with high integration, strong function, simple operation, ease of use. Oscilloscope function in the realization of the traditional software design based on the increase, can easily achieve spectral analysis, multimeter, frequency counter and other functions, to achieve a multi-purpose instrument.
References 1. Li, Z., Ke, X., Wang, Y.: History of the development of virtual instruments to study the current situation and prospects. Anhui University of Technology Institute of Technology 18(4), 104 (2003) 2. Zhang, A.: With virtual instrument LabVIEW introduction. Electronic Industry Press, Beijing (2004) 3. Yang, L., Li, H., Zhao, Y., et al.: LabVIEW Advanced Programming. Tsinghua University Press, Beijing (2003) 4. Yang, L., Li, H., Yang, L.: LabVIEW program design and application, vol. 7, pp. 424–4301. Electronic Industry Press (2006) 5. National Inst rument Crop.LabVIEW7 express User Manual. National Instrument Crop, Texas (1999) 6. Gustavsson, I.: Remote laboratory experiment select rical engineering education. In: Fourth IEEE International Caracas Conference on Devices,Circuits and Systems.Aruba:[s.n.] (2002) 7. Mao, D., Guo, Q.: Using DataSocket techniques to realize the LabVIEW networked application. Modern Electronic Technology 3, 70071 (2003) 8. de Yun, Y., Wei, C.: Based on the measurement and control system of the LabVIEW and its application in teaching. Electronics Industry Press (2005) 9. Tang, Q., Teng, S., Huang, H.: The Design of Multifunctional Virtual Os cillos cope based on LabVIEW. Computer 23(1-1), 151–152 (2007) 10. Cai, J., Chen, J.: The application of Engineering Software based on LabVIEW. ChongQing University Press (2006)
Verifiable Rational Multi-secret Sharing Scheme* Yongquan Cai, Zhanhai Luo, and Yi Yang College of Computer Science and Technology, Beijing University of Technology, Beijing 100022, China [email protected], [email protected], [email protected]
Abstract. In this paper we mainly focus on the cheating problem and the incapability problem existed in rational secret sharing schemes. Based on current schemes and the related knowledge of bit commitment agreement, we proposed a verifiable rational multi-secret sharing scheme in which players can verify the identity of the dealer. In this way, it is feasible to prevent the forger from cheating. The correctness of the secret share is also guaranteed by discrete logarithm problem. The secret shares are divided into groups so that the distribution phase is well designed. The game theory model is also adopted to realize the rational multi secret sharing. The efficient of our scheme has remarkably improved in this protocol as well as the security and feasibility. Keywords: secret sharing, verifiable, bit commitment, rational, multi-secret.
1
Introduction
After Diffie and Hellman first raised the concept of Public key cryptography [1] in 1976, key management becomes a main focus of the study among scholars. Shamir [2] and Blakely [3] separately proposed the threshold secret sharing theory, so that the key management and key storage problem have been well plotted in their schemes. From then on this mechanism becomes the design basis in many security protocols. However, with the development of recent research, it turns out to be many security and feasibility disadvantage in their schemes. Under that circumstance, improvement should be raised aiming at dealing with the cheating problem. B.Chor and S.Goldwasser raised the first VSS scheme in which user can verify the correctness of the secret share [4]. After then a PVSS scheme is raised by Stadler without the strict channel condition in VSS [5]. It means any users in the protocol are capable of publicly verifying the sub secret share. Nevertheless, his scheme demands a comparably large amount of time and space which makes it very complicated and low efficient. So in order to combine high efficiency and high security, many schemes have been raised such as [6] and [7] to meet real practical application. To share multi secret at one time, Dawson brought about a one-way hash function that one-time implementation ensures multi secrets sharing [8]. Harn proposed an efficient VSS scheme that is greatly improved in the aspect of security [9]. In 2004, Halpern and Teague combined the game theory with secret sharing then proposed a first rational secret sharing. In rational secret sharing, it’s assumed that the players are *
This work was supported by Beijing municipal natural science foundation (NO. 1102003).
rational which means they follow the protocol in order to maximize their incomes. Their scheme has a great practical use and significance. And their scheme can prevent the backward induction [10]. Abraham raised an anti-coalition scheme in which sharing secret is distributed with a certain probability [11]. With the probability being well chosen, the nash equilibrium can be reached and k players’ coalition can be prevented. In 2008, Gordon-Kartz analyzed H-J’s scheme. A new scheme was raised that has the feature of communicating with a probability. The players are not aware of the current round so they won’t deviate. With mutual verification, it doesn’t have to rely on the dealer like former schemes [12]. Maleka related repeated games to rational secret sharing to make sure the secret are distributed randomly [13]. Besides, Kol gave a theory of implementing game theory into the analysis of the cryptographic research and they gave a guide to latter analysis [14]. After a great job done by the scholars, rational secret sharing has many achievements. Such as references [15], [16] and [17].
2
Related Theory
2.1
One-Way Hash Function
The one-way hash function H(x) satisfies the following properties: (1) Given the any length of string x, the function can mapped it to fixed length bit stream. (2) Given the value H(x), it’s hard to compute the value x in random polynomial time algorithm. (3) Give the value x, it’s hard to find another function F(x) that satisfies F(x) =H(x). (4) Select two different number x and y, for the hash function that finding an equation that satisfies H(x) =H(y) is impossible. 2.2
Bit Commitment Protocol
As the basis for many cryptographic protocols, the bit commitment protocol has a large range of scenarios, such as electronic voting and e-commerce applications. In our scheme, we improve the bit commitment protocol based on a one-way hash function [18] and ensure that the identity of the dealer is detected by the improved protocol during the distribution phase. The original protocol as follows: (1) First select two strings s1 and s2 randomly. Then select a collision-free one way hash function H , assume that the message to be commitment is s . (2) The player A computes the message H ( s1 || s2 || s ) , and sends s1 to player B.
Publishes the data H ( s1 || s2 || s) . (3) In the commitment phase, player A sends the message ( s1 || s2 || s ) to player B. (4) When player B has received the message, he hashes the message using the function H , and then makes a comparison with the published data based on the received message. If they are the same, then the message be commitment is valid.
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Y. Cai, Z. Luo, and Y. Yang
(5) The player A can not change the commitment message, also he can not find any s2 ' and s ' that satisfies the following equation: H ( s1 || s2 || s) = H ( s1 || s2 ' || s ') . 2.3
(1)
Game Theory Model
Given the set of players A = A1 × A2 × ..... An , the nash equilibrium strategy set is
σ (σ 1 , σ 2 ...σ n ) , σ i ' is the deviate strategy for player Ai , U i + is the income of player Ai when he deviate from the nash equilibrium strategy and also get the secret, the probability is β . In contrast, U i − is the income for player when the player didn’t get the secret. U i is the income for player Ai when the player follow the nash equilibrium strategy. The mixed strategy of nash equilibrium satisfies the following inequality:
β × U i + (σ i ', σ − i ) + (1 − β ) × U i − (σ i ', σ − i ) < U i (σ i , σ − i ) .
The Dealer first selects two strings si1 and si 2 randomly for each player Pi . Then selects the collision-free one way hash function H . Computes the message ( si1 || si 2 || ID ) and H ( si1 || si 2 || ID) . Send the si1 and si 2 to the player Pi . Published the data H ( si1 || si 2 || ID) . When the player Pi had received the above message, based on the identity information of the dealer negotiated in the initial phase, he hashes the message and the negotiated identity information with hash function H . Make a comparison with the published data. If they are not the same, then the player can conclude that the commitment message is not valid and waiting for the correct commitment message from the dealer, otherwise, the protocol go to the distribution phase. 3.2
Distribution Phase
Select two lager prime numbers p and q that meets q | p − 1 . Select finite field Z p , *
the generator g and satisfies g q = 1mod p , Select other two large prime numbers z , s , compute N = zs ,in which it is difficult to decomposition the large number N . Assume that the secrets to be shared are S1 , S2 ,......S k , the number of the secrets is k . The set of the players is {P1 , P2 ,.....Pn } . The number of players is n , select the threshold value t . Select the round R which send the correct secret share with probability η , based on the hash function H , compute the data H ( R || S1 || S 2 || ...Sk ) , published the following data:
Verifiable Rational Multi-secret Sharing Scheme
45
G = g S1 + S2 +......+ Sk mod p .
(3)
G1 = g H ( R||S1 || S2 ||...Sk ) mod p .
(4)
In every round L , the implementation of the protocol is as following: Compute the data r = max(k , t ) , the depth of the polynomial the protocol to construct is r − 1 . The data l = k / t is the number of secret share that the each player Pi should receive. If the current round L is the correct round that send the valid secret shares, and then select the correct secrets as the coefficient of the polynomial. Otherwise, select invalid secrets in finite field randomly as the coefficient of the polynomial. Assume that the secrets to be shared in current round are S1 ', S 2 ',....S k ' . The polynomial satisfies ai = Si +1 'mod p . Generate the polynomial as follows: F ( x) = a0 + a1 x + a2 x 2 + ....... + ar −1 x r −1 mod p .
(5)
The sequence number of the secret shares of the player Pi is IDl×i−l+1, IDl×i−l+2......IDl×i . Select the key pair ( xi , yi ) of RSA encryption system for each player Pi , then encrypt the secret share and published the data C j as the following equations : Eencrypt ( F ( IDi )) = F ( IDi ) yi mod p .
(6)
C j = g j mod p ( j = 0,1, 2....r − 1) .
(7)
a
Send the cipher text of the secret shares and the private key xi of RSA encryption system to the corresponding players. 3.3
Verification Phase
When player receive the secret shares after be encrypted which number of l , first decrypt the cipher text with the following equation: Ddecrypt ( Eencrypy ( F ( IDi ))) = F ( IDi )
yjxj
= F ( IDi ) mod p .
(8)
Verify the correctness of the secret share with following equation: t −1
g F ( IDi ) = ∏ (C j ) IDi mod p . j
(9)
j =0
In equation (8), the player uses the private key xi of RSA encryption system decrypt the cipher text. If the above equation (9) holds on, then the secret shares is correct, the protocol go to the reconstruction phase, otherwise, it is incorrect, and stop the protocol.
46
3.4
Y. Cai, Z. Luo, and Y. Yang
Reconstruction Phase
Any set of players more than t can reconstruct the secrets to be shared with cooperation. The player Pj send secret shares to other players Pi , then Pi use the following equation to verify the correctness of the secret shares with the equation (10). If the equation holds on, the secret shares are correct, use the following Lagrange equation to construct the secrets: r
r
x − IDj
i =1
j =1, j ≠i
IDi − IDj
F(x) = F(IDi ) ∏
= a0 + a1 x + a2 x2 + ....... + ar −1xr −1 mod p .
(10)
The polynomial satisfies a0 = S1 ' mod p , a1 = S2 'mod p ,….. ar −1 = S r ' mod p .Use the following equations to verify the validity of the secrets: G = g S1 '+ S2 '+......Sk ' mod p .
(11)
G1 = H ( L || S1 ' || S 2 ' || ...S k ') mod p
(12)
If the above equations hold on, then the current round is the round that send the real secret, stop the protocol. Otherwise, the protocol goes to the next round.
4
Analysis of the Scheme
(1) We improve the bit-commitment protocol which is based on one-way hash function. The improved protocol ensures that during the secret distribution phase, every player can verify the dealer’s identity as well as other players. The problem that some attackers may forge the identification information of the dealer or other players is successfully solved. The bit-commitment protocol based on one-way hash function has robust security. It is impossible for attackers to forge identification information such as H ( si1 || si 2 || ID) = H ( si1 || si 2 || ID ') in random polynomial time. (2) In this scheme, the dealer encrypts the secret shares to be sent to players using RSA public-key encryption algorithm. Based on the impossibility of factoring large numbers, It is difficult for attackers to forge valid encryption information. Compared with the previous multi-secret sharing scheme, the transmission security of secret shares is greatly improved. (3) Based on discrete logarithm problem, players can identify the correctness of the t −1
secret shares sent by dealer using g F ( IDi ) = ∏ (C j ) IDi . In the secret reconstruction j
j =0
phase, players can identify the correctness of the secret shares sent by other players t −1
using g F ( IDi ) = ∏ (C j ) IDi . Based on discrete logarithm problem, it is computably j =0
j
Verifiable Rational Multi-secret Sharing Scheme
47
infeasible for malicious players to forge valid authentication information. The public information dose not contains any information that can deduce the secret shares. This scheme can provide computably security for the shared secrets and is resistant to coalition attacks up to (n − 1) / 2 players including the dealer. (4) Through one-way hash function and discrete logarithm problem, this scheme successfully seals the number of the rounds that distribute the secret shares correctly. This makes players are not aware of whether the current round is the round in which correct secret shares are sent. By setting the probability η , the strategy set of players can reach nash equilibrium.. The η is set as follows:
η<
U i (σ i , σ − i ) − U i − (σ i ', σ − i ) . U i + (σ i ', σ − i ) − U i − (σ i ', σ − i )
(13)
That is, the strategy set that the player follows the protocol correctly σ (σ 1 , σ 2 ...σ n ) is a nash equilibrium strategy set. According to nash equilibrium, the players’ expect utility of deviating protocol is less than that of following the protocol honestly. And it satisfies the following inequality:
η × U i + (σ i ', σ −i ) + (1 − η ) × U i − (σ i ', σ −i ) < U i (σ i , σ − i ) .
(14)
In the above inequality, the left side is the players’ expect utility of deviation and the right side is players’ utility of follow the nash equilibrium strategy set.
5
Conclusion
In this paper, we analyze the existing rational secret sharing scheme in which there are many security problems, and then give a new verifiable rational secret sharing scheme that can realize multi secret sharing simultaneously. In distribution phase the dealer’s identity has been authenticated by the players based on improved one-way hash function’s bit commitment agreement. It can successfully prevent the attacker from forging the fake secret share by means of RSA public key encryption system. The integrity and confidentiality of the secret share are secured while the dependence of the communication channel is decreased. By taking group distribution of the secret share into consideration, we manage to descend the complexity and low efficiency in former schemes. Meanwhile, the player can verify their share using discrete Logarithm and the parameters published by the dealer. In reconstruction phase, players are capable of mutual verification of each others’ secret share without any leak of the information. In conclusion, compared with former schemes, our scheme has a great improvement in aspects of security, generality and execution efficiency.
References 1. Diffie, W., Hellman, M.: New Directions in Cryptography. J. IEEE Transaction on Information Theory 22(6), 644–654 (1976) 2. Shamir, A.: How to share a secret. J. Communications of the ACM 22(11), 612–613 (1979)
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3. Blakely, G.R.: Safeguarding Cryptographic Keys. In: Proc. AFIPS 1979 National Computer Conference, New York, NY, pp. 313–317 (1979) 4. Chor, B., Goldwasser, S., Micali, S., Awerbuch, B.: Verifiable secret sharing and achieving simultaneity in the presence of faults. In: Proceedings of the 26th IEEE Symposium on the Foundations of Computer Science, pp. 383–395 (1985) 5. Stadler, M.: Publicly Verifiable Secret Sharing. In: Maurer, U.M. (ed.) EUROCRYPT 1996. LNCS, vol. 1070, pp. 190–199. Springer, Heidelberg (1996) 6. Schoenmakers, B.: A Simple Publicly Verifiable Secret Sharing Scheme and its Application to Electronic Voting. In: Wiener, M. (ed.) CRYPTO 1999. LNCS, vol. 1666, pp. 148–164. Springer, Heidelberg (1999) 7. LiaoJun, P., QingQi, P., LiCheng, J., Yu-Min, W.: An Identity (ID)-Based Threshold Multi-Secret Sharing Scheme. Journal of Software 19(10), 2739–2745 (2008) 8. Dawson, H.J., Dawson, E.: Multisecret-sharing Scheme Based on One-way Function. J. Electronic Letters 31(2), 93–95 (1995) 9. Harn, L.: Efficient sharing (broadcasting) of multiple secrets. J. IEE Proc. Comput. Digit. Tech. 142(3), 237–240 (1995) 10. Halpern, J., Teague, V.: Rational Secret Sharing and Multiparty Computation. In: Proceedings of the 36th Annual ACM Symposium on Theory of Computing (STOC), pp. 623–632 (2004) 11. Abraham, I., Dolev, D., Gonen, R.: Distributed computing meets game theory. Robust mechanisms for rational secret sharing and multiparty computation. In: Proc. of 25th ACM PODC, pp. 53–62. ACM Press, Denver (2006) 12. Gordon, S.D., Katz, J.: Rational Secret Sharing. In: De Prisco, R., Yung, M. (eds.) SCN 2006. LNCS, vol. 4116, pp. 229–241. Springer, Heidelberg (2006) 13. Maleka, S., Shareef, A., Pandu, R.C.: Rational Secret Sharing with Repeated Games. J. Information Security Practice and Experience, 334–346 (2008) 14. Kol, G., Naor, M.: Cryptography and Game Theory: Designing Protocols for Exchanging Information. In: Canetti, R. (ed.) TCC 2008. LNCS, vol. 4948, pp. 320–339. Springer, Heidelberg (2008) 15. Zhang, E., Cai, Y.Q.: A New Rational Secret Sharing Scheme. J. China Communications 7(4), 18–22 (2010) 16. Li, D.-w., Yang, G., Yu, C.-g.: A Survey of Rational Secret Sharing schemes. Journal of Nanjing University of Posts and Telecommunications (Natural Science) 30(2), 89–94 (2010) 17. Shareef, A.: Brief Announcement: Collusion Free Protocol for Rational Secret Sharing. In: 29th ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing, Zurich, Switzerland, July 25-28, pp. 402–403 (2010) 18. Halevi, S., Micali, S.: Practical and Provably-Secure Commitment Schemes from Collision-Free Hashing. In: Koblitz, N. (ed.) CRYPTO 1996. LNCS, vol. 1109, pp. 22–24. Springer, Heidelberg (1996)
Limit Theorems and Converse Comparison Theorems for Generators of BSDEs Shiqiu Zheng, Yali He, Aimin Yang, Xiaoqiang Guo, and Ling Wang College of Sciences, Hebei United University, Tangshan 063009, P.R. China [email protected]
Abstract. In this paper, we establishes a limit theorem of backward stochastic differential equations (BSDEs) where the coefficient is independent of y and uniformly continuous in z. With this limit theorem, some converse comparison theorems of this kind of BSDEs are established. Keywords: Backward stochastic converse comparison theorem.
1
differential
equation, generator,
Introduction
Nonlinear BSDEs were first introduced by Pardoux and Peng [10], who proved the existence and uniqueness of a solution under suitable assumptions on g and ξ , the most standard of which g is Lipschitz continuous with respect to (y, z) and ξ is the square integrability. There are many works published to find weaker conditions rather than the Lipschitz condition, such as Lepeltier and Martin [7], and Jia [6], etc. For studying the converse comparison theorem, a limit theorem for generator of BSDEs is established, which shows a relation between generator and solution of BSDE in limit form. Limit theorem is first established by Briand et al.[1], and then generalized by Jiang [4,5], Fan and Hu [3] and Liu Jiang and Xu [8]. In fact, many problems on BSDEs theory and nonlinear expectation theory are related to the limit theorem. For example, with the limit theorem, many important results have been obtained in Briand et al. [1] and Jiang [4,5], etc. Recently, Jia [6] show the uniqueness of solution to a class of BSDEs whose coefficient is independent of y and uniformly continuous in z. The existence of solution to this equation is the result of Lepeltier and Martin [7]. A nature problem is: can we establish a limit theorem for this kind of BSDEs? the answer is positive. In this paper, we mainly establish a limit theorem of BSDEs under the conditions in Jia [6], we also study converse comparison problems for this kind of BSDEs, some interesting results are obtained.
C. Liu, J. Chang, and A. Yang (Eds.): ICICA 2011, Part II, CCIS 244, pp. 49–56, 2011. c Springer-Verlag Berlin Heidelberg 2011
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Preliminaries
Let (Bt )t≥0 be a d -dimensional standard Brownian motion defined on a complete probability space (Ω, F , P ), starting from B0 = 0, let (Ft )t≥0 be the filtration generated by the Brownian motion (Bt )t≥0 and augmented by the set of all P -null subsets. For any positive integer n, we use | · | to denote the norm of the Euclidean space Rn . Let T > 0 be a given real number. Without loss of generality, in this paper, we only consider processes indexed by t ∈ [0, T ]. We define the following usual spaces: Lp (Ft ) := {ξ R-valued, Ft -measurable random variable; E [|ξ|p ] < ∞}, ∀t ∈ [0, T ], p ≥ 1; d d 2 (0, T ; R ) := {ψ R -valued, progressively measurable process; H T E 0 |ψt |2 dt < ∞}. We consider a function g: g (ω, t, z) : Ω × [0, T ] × Rd −→ R such that (g(t, z))t∈[0,T ] is progressively measurable for each z ∈ Rd . For the function g, in this paper, we will use the following assumption: (A1). There exists a continuous, non-decreasing, subadditive function φ such that |g (t, z1 ) − g (t, z2 ) | ≤ φ (|z1 − z2 |) , P − a.s., ∀t ∈ [0, T ], z1, z2 ∈ Rd . where φ : R+ −→ R+ , φ(0) = 0, and there exists a positive real number C1 such that φ(x) ≤ C1 (|x| + 1), P − a.s., ∀t ∈ [0, T ], z ∈ Rd . By (A1), there exists a positive real number C2 such that |g (t, z) | ≤ C2 (|z| + 1), P − a.s., ∀t ∈ [0, T ], z ∈ Rd . Let us consider a BSDE of the following type T T yt = ξ + g (s, zs ) ds − zs dBs , 0 ≤ t ≤ T, t
(2.1)
t
where g is said to be generator, (g, T, ξ) are called standard parameters. We denote the solution of BSDE (2.1) with standard parameters (g, T, ξ) by (Yt (g, T, ξ), Zt (g, T, ξ))t∈[0,T ] . When g satisfies assumption (A1), for all ξ ∈ L2 (FT ), Jia (2008) showed that BSDE (2.1) has a unique solution (yt (g, T, ξ), zt(g, T, ξ))t∈[0,T ] in H2 (0, T ; R1 +d ). Under the standard condition (i.e. Lipschitz continuity of g w.r.t (y, z) and the square integrability of ξ ), Jiang [5] established the following limit theorem for BSDEs. Lemma 2.1. Let the generator g satisfy the standard condition and 1 ≤ p < 2, then for any (y, z) ∈ R × Rd , the following equality: 1 g(t, y, z) = Lp − lim+ [yt (g, t + ε, y + z · (Bt+ε − Bt )) − y] ε→0 ε
Limit Theorems and Converse Comparison Theorems
51
holds for almost every t ∈ [0, T [. We end this section by introducing the following lemma 2.2 from Jia (2008, lemma 2). Lemma 2.2. Let g satisfies the assumptions (A1) and K = max{C1 , C2 }, for ∀n ≥ K, we consider the sequence (g n )n≥K and (g n )n≥K defined by g n (t, z) = g n (t, z) =
sup z ∈Q×Q×Qd
inf
z ∈Q×Q×Qd
{g(t, z ) − n|z − z|}, {g(t, z ) + n|z − z|},
respectively, then we have ∀(t, z) ∈ [0, T ] × Rd , (i) |g n (t, z)| ≤ C(|z| + 1), |g n (t, z)| ≤ C(|z| + 1); (ii) g n (t, z) g(t, z), g n (t, z) g(t, z), as n −→ ∞; (iii) |g n (t, z) − g n (t, z )| ≤ n(|z − z |), |g n (t, z) − g n (t, z )| ≤ n(|z − z |); 2c 2c (iv) 0 ≤ gn(t, z) − gn (t, z) ≤ φ( n−c ), 0 ≤ g n (t, z) − gn (t, z) ≤ φ( n−c ).
3
Main Results
3.1
Limit Theorems for Generator
Let ε ∈]0, T − t], for each (t, y, z) ∈ [0, T [×R × Rd , we denote the solution of the following BSDE: t+ε t+ε ε ε ys = y + z · (Bt+ε − Bt ) + g (u, zu ) du − zuε dBu , 0 ≤ s ≤ t + ε. (3.1) s
(ysε
s
zsε )s∈[0,t+ε] .
by Note that if g in BSDE (3.1) is replaced by g n and g n defined in Lemma 2.2, then we denote the solution of BSDE (3.1) by (y n,ε z n,ε s )s∈[0,t+ε] s n,ε n,ε and (y s z s )s∈[0,t+ε] , respectively. Now let us state and prove our limit theorem for generators of BSDE (2.1) under condition A(1). Theorem 3.1. Let the generator g satisfy assumption (A1) and 1 ≤ p < 2, then for any (y, z) ∈ R × Rd , the following equality: g(t, z) = Lp − lim
ε→0+
1 [yt (g, t + ε, y + z · (Bt+ε − Bt )) − y], ε
(3.2)
holds for almost every t ∈ [0, T [. Proof. Let g n and gn are defined associated g as in Lemma 2.2. For every t ∈ [0, T [ and for any (y, z) ∈ R × Rd , we have 1 n,ε (y − yn,ε ) t ε t 1 t+ε 1 t+ε n,ε = [g n (s, zsn,ε ) − g n (s, zsn,ε )]ds − (z s − z n,ε s )dBs . ε t ε t
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Taking condition expectation in both sides, we have 1 n,ε (y − y n,ε ) t ε t t+ε 1 1 t+ε n,ε = E[ [g n (s, zsn,ε ) − g n (s, zsn,ε )]ds − (z s − z n,ε s )dBs |Ft ] ε t ε t 1 t+ε = E[ [g n (s, zsn,ε ) − g n (s, zsn,ε )]ds|Ft ]. ε t Then by lemma 2.2 and (A1), we have 1 lim lim E| (y n,ε − y n,ε )|p t ε t 1 t+ε = lim lim E|E[ [g (s, zsn,ε ) − gn (s, zsn,ε )]ds|Ft ]|p n→∞ ε→0+ ε t 2c ≤ lim E|2φ |p n→∞ n−c = 0. n→∞ ε→0+
(3.3)
For almost every t ∈ [0, T [ and for any (y, z) ∈ R × Rd , by Lemma 2.1 and Lemma 2.2, we have 1 lim E| (y n,ε − y) − gn (t, z)|p = 0. ε t
ε→0+
(3.4)
By lemma 2,2 and Lebesgue’s dominated convergence theorem, we have lim E|g n (t, z) − g(t, z)|p = 0.
n→∞
(3.5)
By the argument in Jia [6], we have y n,ε ≤ ytn,ε ≤ y n,ε t . t Then we have 1 lim E| (ytε − y) − g(t, z)|p ε 1 ε 1 1 lim E| (yt − y) + (y n,ε − y) − (yn,ε − y) + gn (t, z) − g n (t, z) − g(t, z)|p ε ε t ε t ε→0+ 1 1 lim E| (ytε − yn,ε ) + [ (yn,ε − y) − g n (t, z)] + [g n (t, z) − g(t, z)]|p t ε ε t ε→0+ 1 1 3p−1 lim [E| (ytε − yn,ε )|p + E| (ytn,ε − y) − g n (t, z)|p + E|g n (t, z) − g(t, z)|p ] t ε ε ε→0+ 1 n,ε 1 n,ε p−1 n,ε p 3 lim [E |y t − y t | + E| (yt − y) − g n (t, z)|p + E|g n (t, z) − g(t, z)|p ]. ε ε ε→0+ ε→0+
= = ≤ ≤
Let n → ∞, by (3.3), (3.4) and (3.5), we can deduce 1 lim E| (ytε − y) − g(t, z)|p = 0. ε
ε→0+
Limit Theorems and Converse Comparison Theorems
53
The proof is complete. Now we give the following two assumptions: (A2). ∀t ∈ [0, T ], z ∈ Rd , (g(t, z))t∈[0,T ] is deterministic, i.e. g (t, z) : [0, T ] × Rd −→ R; (A3). The process (g(t, 0))t∈[0,T ] ≡ 0. Note that under the standard condition and (A3), Peng [11] introduce a nonlinear expectation: g-expectation. Now we have the following theorem. Theorem 3.2. Let the generator g satisfy assumption (A1), (A2) and 1 ≤ p < 2, then for any (y, z) ∈ R × Rd , the following equality: g(t, z) = lim
ε→0+
1 [yt (g, t + ε, y + z · (Bt+ε − Bt )) − y] ε
(3.6)
holds for almost every t ∈ [0, T [. Moreover if g also satisfy assumption (A3), then for any (y, z) ∈ R × Rd , the following equality: g(t, z) = lim
ε→0+
1 [y0 (g, t + ε, y + z · (Bt+ε − Bt )) − y] ε
(3.7)
holds for almost every t ∈ [0, T [. Proof. Similar argument as the proof of Jiang [5, Theorem 1.3.6]. If g satisfy assumption (A1), (A2), then we have yt (g, t + ε, y + z · (Bt+ε − Bt )) is deterministic, so (3.6) holds. If g satisfy assumption (A1) and (A3), then we can easily check the fact that ys (g, T, c)) = c, s ∈ [0, T ],
(3.8)
for any constant c. Thus we have yt (g, t + ε, y + z · (Bt+ε − Bt )) = y0 (g, t + ε, y + z · (Bt+ε − Bt )). Then by (3.6), we get (3.7). The proof is complete. Remark 3.1. In fact, since the generator g(t, z) is independent of y, we can choose y in (3.2), (3.6) and (3.7) arbitrarily. Remark 3.2. In theorem 3.1, Moreover if we also suppose g satisfy assumption (A3), then (3.2) is equivalent to g(t, z) = Lp − lim
ε→0+
1 yt (g, t + ε, z · (Bt+ε − Bt )), ε
(3.9)
since under assumption (A1) and (A3), we can easily check the fact that ∀s ∈ [0, T ], η ∈ Fs , ξ ∈ L2 (FT ) ys (g, T, ξ + η) = ys (g, T, ξ) + η.
(3.10)
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3.2
Converse Comparison Theorems for Generators
Converse comparison problem for BSDEs under standard condition has been studied by Briand et al. [1], Coquet et al. [2] and Jiang [4,5]. Using the limit theorem, this subsection will study converse comparison problem for generators of BSDE (2.1) under condition (A1). Theorem 3.3. Let two generators g1 and g2 satisfy the assumptions (A1), then the following three statements are equivalent: (i) For each z ∈ Rd , we have g1 (·, z) ≥ g2 (·, z), a.s., a.e.; (ii) For each t ∈ [0, T ], ξ ∈ L2 (Ft ), P − a.s.,
ys (g1 , t, ξ) ≥ ys (g2 , t, ξ),
∀s ∈ [0, t];
(iii) There exists y ∈ R, such that for each (t, z) ∈ [0, T [×Rd , ε ∈]0, T − t], P − a.s.,
yt (g1 , t + ε, y + z · (Bt+ε − Bt )) ≥ yt (g2 , t + ε, y + z · (Bt+ε − Bt )).
Proof. From the comparison theorem of BSDEs with continuous coefficient (see Liu and Ren [9, Theorem 1.1]), it follows that (i) implies (ii); It is clearly that (ii) implies (iii). We now prove (iii) implies (i). For any (y, z) ∈ R × Rd , we set Oiy,z = {t ∈ [0, T [ | gi (t, z) = L1 − lim
ε→0+
1 [yt (gi , t + ε, y + z · (Bt+ε − Bt )) − y]}, i = 1, 2. ε
Then ∀t ∈ Oiy,z , we have gi (t, z) = L1 − lim
ε→0+
1 [yt (gi , t + ε, y + z · (Bt+ε − Bt )) − y], i = 1, 2. ε
∞ Obviously, ∀t ∈ Oiy,z , there exists a subsequence {nk }∞ k=1 of {n}n=1 such that
gi (t, z) = lim nk [yt (gi , t + 1/nk , y + z · (Bt+1/nk − Bt )) − y], i = 1, 2. (3.11) k→∞
Then by (3.11) and condition (iii), there exists y ∈ R, such that ∀t ∈ O1y ,z ∩ O2y ,z , we get g1 (t, z) ≥ g2 (t, z), a.s.. (3.12) From theorem 3.1, it follows that ∀z ∈ Rd , λ [0, T ] \ O1y ,z ∩ O2y ,z = 0,
(3.13)
where λ denote Lebesgue’s measure. Then by (3.12) and (3.13), we have ∀z ∈ Rd , g1 (·, z) ≥ g2 (·, z), a.s., a.e.. Therefore (iii) implies (i). The proof is complete. Theorem 3.4. Let two generators g1 and g2 satisfy the assumptions (A1), (A2) and (A3) , then the following four statements are equivalent: (i) For each z ∈ Rd , we have g1 (·, z) ≥ g2 (·, z), a.s., a.e.; (ii) For each ξ ∈ L2 (FT ),
Limit Theorems and Converse Comparison Theorems
P − a.s.,
55
y0 (g1 , T, ξ) ≥ y0 (g2 , T, ξ);
(iii) There exists y ∈ R, such that for each (t, z) ∈ [0, T [×Rd , ε ∈]0, T − t], P − a.s.,
y0 (g1 , T, y + z · (Bt+ε − Bt )) ≥ y0 (g2 , T, y + z · (Bt+ε − Bt )).
(iv) For each (t, z) ∈ [0, T [×Rd , ε ∈]0, T − t], P − a.s.,
Proof. By comparison theorem of BSDEs with continuous coefficient (see Liu and Ren [9, Theorem 1.1]) , we have (i) implies (ii); It is clearly that (ii) implies (iii); By (3.10), we have (iii) is equivalent to (iv); Now we only need show (iii) implies (i). Indeed, by (A3) and the uniqueness of solution to BSDE (2.1), for i = 1, 2, we can check that ∀t ∈ [0, T ], ξ ∈ L2 (Ft ) ys (g, T, ξ) = ys (g, t, ξ), ∀s ∈ [0, t];
(3.14)
ys (g, T, ξ) = ξ, ∀s ∈]t, T ]. Thus we have y0 (gi , T, y + z · (Bt+ε − Bt )) = y0 (gi , t + ε, y + z · (Bt+ε − Bt )), i = 1, 2. (3.15) by (3.7), (3.15) and the proof of theorem 3.3, we can deduce (iii) implies (i). The proof is complete. Remark 3.3. In fact, the converse comparison theorems for BSDEs in Coquet et al. (2001, Theorem 2.1) and Jiang [5, Theorem 2.2.1, Theorem 2.2.3 and Theorem 2.4.2] can not be obtained by their method, if we replace the Lipschitz condition by condition (A1) in their setting, since their proof are dependent on strict comparison theorem for BSDEs, but which does not hold in general under condition (A1) (see Jia [6, Remark 7]). Remark 3.4. Indeed, (3.8), (3.10) and (3.14) are character of solution of BSDE whose solution is unique and generator satisfies (A3), which also can be found in Peng [7] where they are obtained under the standard condition and (A3).
References 1. Briand, P., Coquet, F., Hu, Y., M´emin, J., Peng, S.: A converse comparison theorem for BSDEs and related properties of g-expectation. Electron. Comm. Probab. 5, 101–117 (2000) 2. Coquet, F., Hu, Y., M´emin, J., Peng, S.: A general converse comparison theorem for backward stochastic differential equations. C. R. Acad. Sci. Paris, S´erie I 333, 577–581 (2001) 3. Fan, S.-J., Hu, J.-H.: A limit theorem for solutions to BSDEs in the space of processes Statist. Probab. Lett. 56, 93–100 (2008)
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4. Jiang, L.: Converse comparison theorems for backward stochastic differential equations. Statist. Probab. Lett. 71, 173–183 (2005) 5. Jiang, L.: Nonlinear expectation g-expectation theory and its applications in finance Ph.D Thesis. ShanDong University, China (2008) 6. Jia, G.: A uniqueness theorem for the solution of Backward Stochastic Differential Equations. C. R. Acad. Sci. Paris, Ser. I 346, 439–444 (2008) 7. Lepeltier, J.P., Martin, J.S.: Backward stochastic differential equations with continuous coefficient Statist. Probab. Lett. 32, 425–430 (1997) 8. Liu, Y., Jiang, L., Xu, Y.: A local limit theorem for solutions of BSDEs with Mao’ non-Lipschitz generator. Acta Math. Appli. Sinica, English Series 24, 329– 336 (2008) 9. Liu, J., Ren, J.: Comparison theorem for solutions of backward stochastic differential equations with continuous coeffcient. Statist. Probab. Lett. 56, 93–100 (2002) 10. Pardoux, E., Peng, S.: Adapted solution of a backward stochastic differential equation. Systems Control Lett. 14, 55–61 (1990) 11. Peng, S.: Backward SDE and related g-expectation. In: Backward Stochastic Differential Equations Pitman Res. Notes Math. Ser., vol. 364, pp. 141–159 (1997)
The Fusion of Mathematics Experiment and Linear Algebra Practice Teaching* Yan Yan1, Biaoxiang Liu1, Xiujuan Xu1, and Dongmei Li2 2
1 College of Sciences, Hebei United University Department of Automation Engineering, Tangshan Industrial Vocational Technical College Tangshan, Hebei, China {Yan Yan,yanjxky}@126.com
Abstract. In this paper, it discusses how to lead the methods of mathematics experiments into linear algebra courses teaching. Proposing that we should weaken theoretical analysis and computing skills, pay attention to the way of thinking and application cases in practice teaching. Finally, it gives us some mathematica’s typical commands and application cases in the practice teaching of the linear algebra, which can develop students’ researching abilities. Keywords: Linear Algebra, mathematical software, mathematics experiment.
1
Introduction
Linear Algebra is a branch of mathematics, which researches vector, vector space linear transformations and finite-dimensional linear equations. Vector space is an important topic in modern mathematics, thus, the linear algebra is widely applied to abstract algebra and functional analysis, and it can be indicated concretely by analytic geometry. Liner algebra theory has been generalized to operation theory. Since we can often approximately regard the nonlinear model as the linear model in the scientific research, we makes the linear algebra be widely applied to natural science and social science, at the same time the non-linear problems in the practical problems be solved on the whole by transforming into the linear model. This requires that students not only master the basic theories and methods of linear algebra, but also be able to apply it to solve practical problems. With the proliferation of computers and mathematics software increasingly powerful, computer- assisted instruction has been a general trend, there are two main aspects of computer-assisted instruction, on one hand , it is the multimedia teaching that includes geometric figures shows and other thing, on the other hand ,it is the mathematics experiment, which in turn includes two aspects, one is apply mathematics software to verify the conclusions learned, numbers calculations and deal with practical problems and so on, another is to apply it to discover new conclusions and theorems by skillful calculations or model processing.[1] At present there are many colleges at home and abroad have already applied mathematics experiments to mathematics teaching process, some colleges regard *
The instruction reform project of Hebei United University Z0906-06.
mathematics experiments as a course to set up independently, but they excessively pay attention to making use of mathematics software as well as procedure commands of all kinds of concrete problem, neglect the perfect combination with the teaching process, and neglect to develop students abilities that get the new conclusions from mathematics experiments.
2
The Necessity Introduction of Mathematics Experiments
With the advance of science technology and the continuous development of society, people more and more need to deal with some large-scale linear equations, large-scale matrix problems, the traditional calculations by themselves has already not adapted to the needs of society, in this new situation ,computers are more an d more popular day by day , and all kinds mathematics software functions is more powerful increasingly, if college students cannot master a mathematical software and can skillfully use it to solve practical problems, that their future study and researches will meet with a lot of difficulties. Therefore, adding mathematics experiments is a inevitable trend which adapts to current education situations and matches the laws of understanding with mathematics software in the teaching process of linear algebra. Linear Algebra experimental course will enrich teaching methods and teaching mutual interaction means, strengthen teacher's teams, stimulate students’ interest in mathematics and improve their overall quality. [2]We integrate mathematics experiments into teaching process, but we also should aware that the design of experiments teaching cases come from practice and be applied to practice, realize the three-dimensional interaction between mathematical experiments, theoretical methods, practical issues and mathematics models, and make students obtain knowledge during interesting experiment process as well as learn to apply knowledge to solve problems at the same time.[3]
3
Teaching Cases of Mathematics Experiments
3.1
Determinants and Matrix
Experiment purpose: We should not only master the input methods of matrix and how to take advantage of mathematica to transpose, add, subtract, number multiply, multiply square and do other operations for matrix, but also be able to get inverse matrix and the determinant of calculating phalanx. Basic commands: In Mathematica, the vector and matrix are given in the table.
① ② ③
Table is a number of expressions between curly brackets, and expressions are separated by commas. The generating function of table: The simplest numerical table can generate function Range, and universal table can generate function table. Table as vector and matrix: in the linear algebra, a level of table means vector, and two levels of table mean matrix.
The Fusion of Mathematics Experiment and Linear Algebra Practice Teaching
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④ Command IdentityMatrix [n] generate n-order united matrix. ⑤ Command DiagonalMatrix [...] generate n-order diagonal matrix. ⑥ Matrix linear operation: A + B means the addition of the matrix A and B, k * A
means the multiplication of the number A and matrix B, A.B or Dot [A, B] means the multiplication of the matrix A and matrix B. Work out the transposition command of matrix A: Transpose [A]. Work out the n square’s command of Phalanx A: MatrixPower [A, n]. Work out the command of the inverse Phalanx A. Inverse [A]. Work out the inner multiplication commands of vectors a and b Dot [a, b].
⑦ ⑧ ⑨ ⑩
3.2
The Rank of Matrix and a Group of Vectors’ Maximum Independence Group
Experiment purpose: we can make use of Mathematica to work out the matrix rank, do the primary transformation of matrix, and work out a group of vectors’ rank as well as maximum independence group.[4] Basic commands:
① ② ③
M matrix with all possible k-matrix consisting of sub-type command: Minors [M, k]. The command of turning the matrix A into the simplest line form RowReduce [A]. The command of Joining list1, list2……into a large number list:Join [list1, list2, ...]. 3.3
Linear Equations
Experiment purpose: we can be familiar with the common commands of solving linear equations, be able to make use of Mathematica commands to work out various types Linear Equations’ answers, and understand practical significance of computers to solve problems. Basic commands:
① ② ③
Command NullSpace, give a base of homogeneous equations AX = 0 space solutions. Command LinearSolve, give a particular solution of non-homogeneous linear equations AX=b. The command of solving a general equation or equations Solve. 3.4
Traffic Model (Integrated Experimental)[5]
Experiment purpose: In the linear algebra we can take advantage of vector and matrix operations, solving linear equations and other knowledge to build traffic flow model , what’s more, we can grasp linear algebra’s applications in transportation planning. Application examples:let us assume that some one-way streets in a city traffic (the number of vehicles per hour through) as following.
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x3 300
x2
300 300
100
x4 x1
500
x5
x6 400
600
200
400
x9
x10
600
200
x7
x8 500
700
Try to build a mathematical model to decide the unknown part of the transportation network’s specific traffic flow. We assume that the above problems match the following two basic assumptions. (1) All traffic into the network is equal to all the network traffic flow. (2) All traffic into a node equals the flow out of this node. Thus, according to plans and the basic two assumptions, we can establish the problem’s linear equations
x 2 − x 3 + x 4 = 300 0 x x 500 4+ 5= 0 − x 6 + x 7 = 200 0 x x 800 + = 1 2 1 x + 1x = 800 1 1 5 → 0 x 7 + x 8 = 1000 0 x 9 = 400 0 − x 9 + x10 = 200 x = 600 0 10 x 3 + x 6 + x 8 = 1000 0
If the above matrix equation is denoted AX = b, then the problem is transformed for the sake of AX = b all solutions. Following we use Mathmatica software to solve problems. Input matrix A, and use command RowReduce [A] to obtain that 8 is the rank of A. Enter RowReduce [A] / / MatrixForm Out [2] / / MatrixForm = Apply the command NullSpace [A] to work out the group of the homogeneous linear equations’ a series of basic solutions. Enter In [3]: = NullSpace [A] / / MatrixForm Out [3] / / MatrixForm = Enter the augmented matrix (A b), obtaining the rank of 8, by r(A) = r(Ab) = 8 < n = 10, we can know equation has infinite solutions. Enter RowReduce [Ab] / / MatrixForm
① ② ③
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Out [5] / / MatrixForm Apply command LinearSolve [A, b] to obtain a particular solution of nonhomogeneous linear equations AX = b. Enter LinearSolve [A, b] Out [9] = {{800}, {0}, {200}, {500}, {0}, {800}, {1000}, {0}, {400}, {600}} Then we obtain a particular solution of non-linear equations asked
④
ξ * = (800 0 200 500 0 800 1000 0 400 600) T
To sum up, we get all of solutions of the non-homogeneous linear equations AX = b as following x = η + ξ* + C1ξ1 + C2 ξ 2 + ξ* This model has actually applied value, working out the solution of the model,we can provide the solution to traffic congestion , traffic problems such as poor run and so on for transportation planning and design departments, at the same time, we can know where to build the overpass ,how to design the width of the roads and so on, which provides scientific guidance for urban transportation planning. However, in this model, we only consider a simple case of such one-way streets, leaving to the reader a more complex situation at a higher level course to study. In addition, the Model can also be extended to circuit analysis’s network nodes flow and other issues. 3.5
Approximation by a Piecewise Linear Function[7]
The power of using binary variables to represent intervals can be more fully appreciated when it is desired to approximate a nonlinear function by a piecewise linear one. Specifically, suppose the nonlinear function represents a cost function and we want to find its minimum value over the interval 0 ≤ x ≤ a 3 .If the function is particularly complicated, it could be approximated by a piecewise linear function .[6] Using the approximation suggested our problem is to find the minimum of the function:
b1 + k1 (x − 0) if 0 ≤ x ≤ a1 c(x) = b 2 + k 2 (x − a1 ) ifa1 ≤ x ≤ a 2 b + k (x − a ) ifa ≤ x ≤ a 3 2 2 3 3 Define the three new variables x1 = (x − 0), x 2 = (x − a1 ) , and x 3 = (x − a 2 ) for each of the three intervals,and use the binary variables y1 , y 2 , and y3 to restrict the x i to the appropriate interval: 0 ≤ x1 ≤ y1a1 , 0 ≤ x 2 ≤ y 2 (a 2 − a1 ), 0 ≤ x 3 ≤ y3 (a 3 − a 2 ) ,where y1 , y 2 ,and y3 equal 0 or 1.Because we want exactly one x i to be active at any time, we impose the following constraint: y1 + y 2 + y3 = 1 . Now that only one of the x i is active at any one time, our objective function becomes: c(x) = y1 (b1 + k1 x1 ) + y 2 (b 2 + k 2 x 2 ) + y3 (b3 + k 3 x 3 )
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Obseve that whenever yi = 0 , the varialbe x i = 0 as well. Thus, products of the form x i yi are redundant, and the objective function can be simplified to give the following model: Minimize k1 x1 + k 2 x 2 + k 3 x 3 + y1b1 + y 2 b 2 + y3 b3 subject to 0 ≤ x1 ≤ y1a1 , 0 ≤ x 2 ≤ y 2 (a 2 − a1 ), 0 ≤ x 3 ≤ y3 (a 3 − a 2 ), y1 + y 2 + y3 = 1 where y1 , y 2 ,and y3 equal 0 or 1. 3.6
An Investment Problem[8]
Consider the following problem: An investor has $40,000 to invest. She is considering investments in savings at 7%, municinal bonds at 9%,and stocks that have been consistently averaging 14%. Because there are varying degrees of risk involved in the various investments, the investor has listed the following goals for her portfolio: 1. A yearly return of at least $5000. 2. An investment of at least $10,000 in stocks. 3. The investment in stocks should not exceed the combined total in bonds and savings. 4. A liquid savings account between $5000 and $15,000. 5. The total investment must not exceed $40,000. We can see from the portfolio that the investor has more than one objective. Unfortunately, as is often the case with real-workd problems, not all goals can be achieved simultaneously. If the investment returning the lowest yield is set as low as possible, the best return possible without violating Goals2-5 is obtained by investing $15,000 in bonds and $20,000 in stocks. However, this portfolio falls short of the desired yearly return of $5000.How are problems with more than one objective reconciled?[9][10] Let’s begin by formulating each objective mathematically: Let x denote the investment in savings, y the investment in bonds, and z the investment in stocks. Then the goals are as follows: Goal 1. 0.07x + 0.09y + 0.14z ≥ 5, 000 Goal 2. z ≥ 10, 000 Goal 3. z ≤ x + y Goal 4. 5, 000 ≤ x ≤ 15,000 Goal 5. x + y + z ≤ 40, 000 We have seen that the investor will have to compromise on one ore more of her goals to find a fessible solution. Suppose the investor feels she must have a return of $5000, at least $10,000 in stocks, and cannot spend more than $40,000 but is willing to compromise on Goal 3 and 4. However, she wants to find a solution that minimizes the
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amounts by which these two goals fail. Let’s formulate these new requirements mathematically and illustrate a method applicable to similar problems. Thus, let G 3 denote the amount by which Goal 3 and G 4 the amount by which Goal 4 fail to be satisfied. Then the model is to Minimize G 3 + G 4 Subject to
0.07x + 0.09y + 0.14z ≥ 5, 000 z ≥ 10, 000 z≤x+y 5, 000 ≤ x ≤ 15, 000 x + y + z ≤ 40, 000 where x, y, and z are positive. This last condition is included to ensure that negative investments do not result. This problem is now a linear program that can be solved by the Simplex Method. If the investor believes that some goals are more important than others, the objective function can be weights in the objective function will identify the breakpoints for the range over which various solutions are optimal. This process generates a number of solutions to be carefully considered by the investor before making her investments. Normally, this is the best that can be accomplished when qualitative decisions are to be made.
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Conclusion
We integrate mathematics experiments into teaching process, it perfectly embodies the "Linear Algebra" actually applied value and achieves the three-dimensional interaction between mathematical experiments, theoretical methods, practical issues and mathematics models, and makes students obtain knowledge during interesting experiment process as well as learn to apply knowledge to solve problems at the same time. On the base of making most use of modern teaching methods, we should give attention to both theory and application, which is useful to train multi-level talents.
References 1. Zhu, M.-y.: Mathematics Experiment of Linear Algebra Study Based on Excel Application. Journal of Changzhou Institute of Technology (2) (2007) 2. Xiang, X., Wu, J., Wang, Y.: Linear Algebra Teaching Experiment Preliminary. Journal of Jiujiang University (3) (2008) 3. Yu, P.: A Brief Discussion on the principle of Object Selection for the Course of Mathematics Experiment. Journal of Liaoning Institute of Science and Technology (02) (2009) 4. Li, X.-l., Zhang, H.-y.: Applications of Linear Algebra in Mathematical Modeling. Journal of Shanxi Datong University (Natural Science Edition) (2) (2010)
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5. Li, S.: Under current circumstances Linear Algebra teaching mode investigate. New West (9) (2010) 6. Liu, P., Fu, J.: Theory Reflecting and Practice Exploring for Mathematics Experiment Teaching in Normal University. Jilin Normal University Journal (Natural Science Edition) (01) (2010) 7. Xu, Z., Li, X.: Integration of Mathematical Modeling and Mathematics Experimental Curriculum. Journal of Shenyang Normal University (Natural Science Edition) (03) (2010) 8. Lin, W., Ji, S.: Mathematics Experiment—The Fusion of Mathematics Method’s Mathematical Sotware and Mathematics Applications. College Mathematics (01) (2011) 9. Ma, J., Ni, K., Wu, Z.: The Practice and Thinking of the Case Teaching Model and Teaching Method in Mathematics Experiment. Journal of Yili Normal University(Natural Science Edition) (02) (2010) 10. Yi, M.: Some thoughts in mathematics study and education. In: 2010 International Conference on Management Science and Engineering, MSE 2010 (2010)
Research on the Teaching Method of Geometry in Linear Algebra Yankun Li1, Shujuan Yuan1, Yan Yan2, and Yanbing Liang2 1
Qinggong College, Hebei United University, Tangshan, Hebei, China 2 Hebei United University, Tangshan, Hebei, China [email protected]
Abstract. The linear algebra is an abstract mathematics course. In this paper, some basic and important concepts in linear algebra are explained from the geometrical point of view. Combining with the teaching practice, we explore the teaching method which unifies the linear algebra and the geometry. In this paper, several aspects are discussed, such as the determinant, the linear equations and the linear correlation of the vectors. Keywords: Linear algebra, Geometry, Determinant, Linear equations, Linear correlation.
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Introduction
Linear algebra is the main content of advanced algebra. It has deep geometric background. While analytic geometry is geometric problems to study spaces using algebra methods, especially using vector methods. For this reason, it has its inherent reasonableness to combine linear algebra and analytic geometry into a course. From a historical point of view, the development of algebra and geometry has always been with each other and promote each other. As professor Chen Zhijie says, “Algebra provide research methods for geometry, and geometry is the direct background”. Geometry and algebra are interlinked; they can learn from each other and expand their range of disciplines. Similarly, as the basic of algebra, linear algebra and analytic geometry are also interlinked; they can benefit from each other in the scientific research. At this level, if we put the geometry thought into the linear algebra course in the actual teaching work, then it will be of important significance on training students to learn and to lifting capacity. It is impossible and unnecessary to give each concept a geometric explanation. In this paper, we try to give the linear correlation of determinant, Linear equations and array vector a geometric explanation. We hope by these explain, not only deepen students to the understanding and the understanding of these concepts, but also introduce some special geometric method in the algebra, thereby improving the students’ mathematical culture.
The combination of linear algebra and analytic geometry has several advantages as follow. 2.1
Combination of Abstract and Image
Linear algebra stresses to the theory and model which are abstract, and space analytic geometry provides iconic geometric intuition. Abstract and image can be combined through the combination of linear algebra and space analytic geometry. It is in line with people to the habit and the rule of learning and knowing something. And it helps students to combine conceptual knowledge and perceptual knowledge. Proof is the standard of testing mathematical truth, but the formal logic is not the mode of thinking that is the most adept for human. Thinking in terms of images which includes the intellect and imagination for the space relation is naturally present at birth. For example, vector can be used for denoting straight line and plane. The theory of matricial rank can be used for judging the relationship between the planes, the straight lines and the relationship between the plane and straight line. The eigenvalue and eigenvector of real symmetric matrices can be used for reducing quadric curve, quadric surface and their invariant and halfinvariant. The former one is more abstract algebra theory, and the later one is applying these algebra theories to visual pattern in geometry. 2.2
Make the Class Richer
Integrating the thought of analytic geometry into the linear algebra also is abstract combines with image, it does not exist the problem that which one is primary in the integration between the higher algebra and the analytic geometry. We can appropriately increase class hours, avoid the adverse conditions that there are only two periods a week. Then not only can we reflect the geometric thought, but also it could be propitious to study. And it is convenient for students to master the knowledge. 2.3
More Conducive to Learn Other Mathematical Courses
It will be clear understand to the vector and the spacial structure of three-dimensional graphics when the students learned the linear algebra and the space analytic geometry. And then it is more useful for learning the higher mathematics. Linear algebra and space analytic geometry are conducive to study these difficulties for the students.
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Geometry of the Teaching in Linear Algebra
The algebra and the geometry combine close on the structure is the exact meaning of geometry of the teaching in linear algebra. In this paper, the linear algebra and the geometry thought fusion method will be elaborated from the following several aspects.
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Geometry Background of Determinant
The determinant is the first difficult point for the students. They will only memorize it mechanical and don't understand its geometric meaning because of the traditional definition. That they will feel too hard for the nth-order determinant. In fact, we can lead the students from the angle of geometry to understand the definition of determinant. Using the geometrical perspective, the second-order determinant area of the parallelogram, and the vector
a11 a 21
a1 = (a11 a 21 ) T
a12 is the a 22 and vector
a 2 = (a12 a 22 ) T are the two adjacent edge of the parallelogram. When the parallelogram is got by vector a1 anticlockwise turn to a 2 , the area is a positive value. And when the parallelogram is got by vector a1 clockwise turn to a 2 , the area is a negative value. Similarly we know that the value of the third-order determinant is the volume of the parallel hexahedron, and the parallel hexahedron is formed by the three vectors of the third-order determinant in the space. When the three vectors are right-handed, the volume is positive. And when the three vectors are left-handed, the volume is negative. Naturally, we can lead the students derive the geometrical meaning of the nth-order determinant. That is the volume of the parallel polyhedron which is composed of n-dimensional vector, and the number is n. So, it could reduce the difficulty of understanding the concept though introducing the geometric intuitive teaching method into the determinant. And the students will feel the determinant is a mathematical measure almost tangible. 3.2
The Geometric Explanation of Determinantal Expansion Theorem
The determinantal expansion theorem is an important theorem in the linear algebra. It has the very important role in the determinant calculation. It is abstract for the students, and it is mastered hardly. In the process of teaching, we can use the geometrical background to understand the theorem. There is the third-order determinant as an example.
a11 D = a 21
a12 a22
a13 a 23 = a31 A31 + a32 A32 + a33 A33 .
a31
a32
a33
The A31 , A32 A33 are three algebra cofactors of this determinant.
α 1 = (a11 , a12 , a13 ) , α 2 = ( a 21 , a 22 , a 23 ) , α 3 = (a 31 , a32 , a 33 ) , β = ( A31 , A32 A33 ) , then β = α 1 × α 1 . If set
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| β | denotes the area of the parallelogram which is edged by α 1 and α 2 . And then
D = ( β , α 3 ) =| β || α 3 | cos θ = [α 1 , α 2 , α 3 ] . Use the geometry figure to denote as figure 1.
Fig. 1. The geometry figure of the determinantal expansion theorem
There will produce an intuitive geometric model of the abstract algebra theorem in the mind of students with this method. And the geometric background of the theorem will be clear understood to the students. Thus, the integration of geometric thought can cultivate the students' application ability of this theorem, and the connotation of the theorem could be experienced in the harmony and unity of numbers and forms at the same time. 3.3
The Connection between Linear Equations and Geometry
The position relation between the straight lines and the planes in the space provides intuitive geometric explanation for the theory of linear equations. At the same time, the theory of linear equations in linear algebra has an important role for a deep understanding of the position relation between lines and planes. Below we will show the linear equations which have three variables and three equations as an example for that.
a11 x1 + a12 x2 + a13 x3 = b1 a21 x1 + a22 x2 + a23 x3 = b2 a x + a x + a x = b 32 2 33 3 3 31 1
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The coefficient matrix is A , and the augmented matrix is B . Then the geometric meaning of linear equations has several cases as follow: (1) Each equation is corresponding to a plane in the three dimensional space. (2) If R ( A) < R ( B ) , the linear equations have no solution. And the three planes have no public intersection. (3) If R ( A) = R( B ) = 3 , the linear equations have the only solution. And the three planes intersect at one point. (4) If R ( A) = R ( B ) < 3 , the linear equations have the solution. And the three planes have the public intersection. When R ( A) = R( B ) = 2 , the linear equations have an infinite number of solutions from the angle of algebra. From the angle of the geometry, the two planes coincide and intersect into a straight line with the third one, and each point on the straight line is corresponding to a solution of the linear equations. When R ( A) = R ( B ) = 1 , the linear equations also have an infinite number of solutions. From the angle of the geometry, the three planes coincide together, and each point on the plane is corresponding to a solution of the linear equations. If the students understand the geometric meaning of the linear equations’ solution, and then the case could be spread to the linear equations with n variables. By applying the geometry thought, students can be hinted as follow in the teaching process: (1) Because three straight lines couldn’t be mutually perpendicular on the plane, three or more different bivariate simple equations have no solution. (2) Because four planes couldn’t be mutually perpendicular in the space, four or more simple equations with three variables have no solution. The students could guess easily the linear equations that the number of equation is greater than the number of unknown quantity have no solution. 3.4
Geometric Meaning of Linear Correlation
In the linear algebra, the concepts of linearly dependent and linearly independent are nodi. By using three-dimensional space of geometry, the abstract concepts will materialize, and it contributes to understand the abstract concepts. Set α , β , γ are vectors in three-dimensional space, then: If α is linearly dependent, then α is the zero vector. If α , β is linearly dependent, then α , β are collinear. If α , β , γ is linearly dependent, then α , β , γ are coplanar. Therefore, the base of one-dimensional space is any nonzero vector in this space. The base of two-dimensional space is two vectors in this space which are not collinear. And the base of three-dimensional space is three vectors in this space which are not coplanar.
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Conclusion
The relationship between linear algebra and analytic geometry is wide. Many theories in the linear algebra can be considered that they are extension from two-dimensional planar space and three-dimensional plastic space. In the course of lesson, we can lead students to understand the concepts and properties in the linear algebra and master the application of conclusion by geometric figure. Then not only can we reach the goal of teaching smoothly, but also we can help students deepen understanding of knowledge and overcome the difficulties of learning linear algebra. So strengthening the intuitive geometry teaching of the linear algebra is an effective method to help students to learn the subject well.
References 1. Min, L., Chen, X.: Researchful Teaching Case on Linear Algebra. Journal of Southwest China Normal University (Natural Science Edition) 35, 206–208 (2010) 2. Liu, J., Wu, M.: Some Ideas on Improving the Teaching Method of Linear Algebra. Studies in College Mathematics 13, 13–15 (2010) 3. Guo, Y.: Merging Geometrical Thought into the Teaching of Linear Algebra. Journal of Yichun College 32, 186–187 (2010) 4. Jaffe, A.: Ordering the universe: The role of mathematics. SIAM Review 26, 473–500 (1984) 5. Yu, Z., Li, Y.: Linear Algebra and Analytic Geometry. Tsinghua University Press, Beijing (1998) 6. Wang, J., Guo, M.: The Cultivation of Geometrical Visual Should Be Strengthened During Linearity Algebra Teaching. Journal Of Xinxiang Teachers College 17(2), 51–53 (2003) 7. Zou, J., Li, G.: Geometrical Methods in Teaching of Linear Algebra. J. North China Univ. of Tech. 10(2), 36–42 (1998) 8. Teng, S.: Research on the Geometrization and Application of Linear Algebra in Teaching. Journal of Adult Education School of Hebei University of Technology 23(3), 23–28 (2008) 9. Xu, D.: Integrating Linear Algebra Teaching with Geometry Interpretation. Journal o f Changzhou Institute of Technology 19(2), 72–75, 86 (2006) 10. How to Inspire the Students Motivation to Learn Mathematics, http://www.studa.net/xueke/070205/13240262-2.html
Exploration the Teaching Method of Linear Algebra Based on Geometric Thought Yankun Li1, Dongmei Li1, Xiaohong Liu1, Jun Xu1, and Linlin Liu2 1
Qinggong College, Hebei United University, Tangshan, Hebei, China 2 Hebei United University, Tangshan, Hebei, China [email protected]
Abstract. Linear algebra is one of the important basic courses for high school. Its abstract course content caused the students have difficulty to accept, and they are lack of motivation to learn. We analyzed the status and inadequate of the course, followed by the necessity and content analysis of the idea, which put geometric thinking into linear algebra teaching practice. It is expected to provide a theoretical reference for linear algebra teaching practice. Keywords: Linear algebra, Geometry, Teaching practice, Determinant, Linear correlation.
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Introduction
Linear algebra is a discipline to study linear spaces and linear transformation. Currently, it has become one of the foundation mathematical course for high school students majoring in engineering, economics, management and other relevant professional. With the popularity of computer science, the importance of course has become increasingly showing. Some of its results and conclusions have been widely applied to probability theory, mathematical statistics, differential equations, discrete mathematics. And it has played a positive role in promoting the development of these disciplines. Linear algebra provide a new approach, which is very helpful in stimulating students logical thinking ability and quality, and improving the ability of students to analyze and solve problems. Therefore, its teaching effect to enhance the overall quality of students is essential. Since linear algebra has features such as strong logic, abstraction and a wide range of applications, there are still some difficulties in teaching, which need to give a more viable option.
linear algebra is abstract content and its independent system. It is this characteristic that makes linear algebra obscure and boring in traditional teaching. Thus, students have difficulty to accept the theory. And it affects enthusiasm for students to study, resulting in the main obstacles of actual teaching.
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Status and Inadequate of the Course
3.1
Vary School Hours and Long Time Interval
Currently, teaching arrangements of linear algebra are different between colleges and universities in China on aspects such as emphasis, teaching content, hours, etc. Hours as an example, there are from twenty hours to sixty hours or more. Generally speaking, most schools set hours from thirty-two to forty, two hours per week on average. As our students are non-math majors, the time interval is too long for them, so that a considerable amount of knowledge has been forgotten. Longer time interval caused it is insufficient to stimulate the excitement of learning. This is another important reason why the students do not learn linear algebra well. 3.2
Rigorous, Abstract Content System and Low Motivation to Learn
The teaching materials we used have been tempered, and are written under the guidance of the principle of combining science and teaching requirements. The background and history of the evolution are abandoned, when many of the concepts and methods formed. Linear algebra is more abstract than higher mathematics. On one hand, strictly logical reasoning develops logical thinking ability of students to some extent. On the other hand, a considerable number of students think linear algebra a dull subject. It is not conducive to stimulate subjective initiative of the students. 3.3
Less Practical Application and Lack of Intuitive Understanding
Liner algebra let the students get in tough with new mathematical tools, such as determinant, matrices, vector spaces, eigenvalues and eigenvectors, which are used in n-linear equations and quadratic simplification. But these uses are still much abstract use. In the actual teaching process, it is not conducive to students’ learning and understanding. Teaching practice shows that in order to effectively improve the effectiveness of linear algebra teaching, so that students truly master this mathematical tool, rather than remembering some of the mechanical procedures, and the abstract definitions and theorems, a countermeasure must be proposed characteristics for linear algebra course.
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Geometry into Linear Algebra
4.1
Relationship between Geometry and Algebra
Linear algebra is the main content of advanced algebra. It has deep geometric background. While analytic geometry is geometric problems to study spaces using algebra
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methods, especially using vector methods. For this reason, it has its inherent reasonableness to combine linear algebra and analytic geometry into a course. From a historical point of view, the development of algebra and geometry has always been with each other and promote each other. As professor Chen Zhijie says, “Algebra provide research methods for geometry, and geometry is the direct background”. Geometry and algebra are interlinked; they can learn from each other and expand their range of disciplines. Similarly, as the basic algebra, linear algebra and analytic geometry are also interlinked; they can benefit from each other in the scientific research. At this level, if we put geometry thinking into linear algebra course in the actual teaching work, then it will be of the important significance on training students to learn and to lifting capacity. 4.2
Necessity Analysis
In order to overcome the abstract linear algebra, the most feasible way is to combine it with analytic geometry, combined teaching. As it is known to all, analytic geometry provides a visual context for linear algebra; while linear algebra provides a research tool for analytic geometry. Actually, in many of the concepts of linear algebra, there is prototype geometry. Some abstract algebra theories become easy to understand after the geometric meaning is given. Conversely, many seemingly complex geometric conclusions, in algebraic point of view, are very simple and clear. Most importantly, linear algebra as an abstract logical system can be discerned rather than blue. That are often able to rise beyond the three-dimensional geometry to high-dimensional space,giving more essential and more extensive results. From this perspective, linear algebra can be regarded as high-dimensional space of analytic geometry. So there is no doubt that the combination of linear algebra and analytic geometry is of high degree of necessity. 4.3
Geometric Meaning of Teaching
The exact meaning of geometry teaching in linear algebra is the two systems of algebra and geometry closely integrated in the structure. As for the tools to deal with algebraic geometry problems, it belongs to the application scope of linear algebra. Certainly, not any linear algebra problems can be implemented geometric. It would not be meaningful pursuit of geometric on one-sided. On the geometry processing of linear algebra, there are two main ways. One way, the domain will be reduced to three-dimensional space, giving the geometric meaning of low-dimensional algebraic problem. For example, when discussing the linear equations, if the unknown variable is limited to three, then solution of equations is equivalent to find the intersection of several planes. While leading into the definition of linearly dependent, it may be noted that it is equivalent to the vector in three-dimensional geometry of collinear or coplanar, and so on. In describing the methods, we often discuss the concept of three-dimensional geometric first, then
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abstract to linear algebra concepts. Obviously, this approach to abstract from the visual is of epistemological and methodological significance. The second way, directly study geometric meaning of algebra problems in the high-dimensional vector space. High-dimensional vector space itself is a set of geometric language. Such as the linear representation, subspace, orthogonal, basis, coordinates, projection, transformation, etc. These are all corresponding representations of three-dimensional geometric concepts in n-dimensional space. Using this high-dimensional geometric language, we can analyze the problem of abstract algebra directly, rather than as a dimension reduction process. In general, to a certain extent, if we seen linear algebra as a high-dimensional geometric, then the essence of the so-called linear algebraic geometry is to establish a relationship with the structure between three-dimensional geometry and highdimensional geometric systems. With this relationship, on the same linear algebra problem, if it can be geometric, then it has geometric meanings both in threedimensional geometry and high-dimensional geometric. The two approaches above are set up for this purpose. For example, “solvability of linear equations” as algebra problem, in the threedimensional geometry could be interpreted as “the intersection of several planes,” while in high-dimensional geometry it would be interpreted as “the intersection of several hyper planes”. But a better explanation is “the right column of the equation falls within the vector space of the coefficient matrix”.
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Examples
5.1
Geometric Meaning of Linear Correlation
In the linear algebra, the concepts of linearly dependent and linearly independent are nodi. By using three-dimensional space of geometry, the abstract concepts will materialize, and it contributes to understand the abstract concepts. Set α , β , γ are vectors in three-dimensional space, then: If α is linearly dependent, then α is the zero vector. If α , β is linearly dependent, then α , β are collinear.
If α , β , γ is linearly dependent, then α , β , γ are coplanar. Therefore, the base of one-dimensional space is any nonzero vector in this space. The base of two-dimensional space is two vectors in this space which are not collinear. And the base of three-dimensional space is three vectors in this space which are not coplanar. 5.2
Geometry Background of Determinant
Set α = ( a1 , a 2 , a 3 ) , β = (b1 , b2 , b3 ) , γ = (c1 , c 2 , c3 ) . The cross product of two vectors can be denoted by the determinant:
Exploration the Teaching Method of Linear Algebra Based on Geometric Thought
i α × β = a1 b1
j a2
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k a3 . b3
b2
It expresses the vector which is both vertical with the vector α and β , and which is right-handed in the geometry. The mixed product of three vectors can be denoted by the determinant:
a1 [α , β , γ ] = (α × β ) ⋅ γ = b1
a2 b2
a3 b3 .
c1
c2
c3
The geometric explanation of this determinant is that, its absolute value equal to the volume of parallel hexahedron which is formed by these three vectors. Particularly, when [α , β , γ ] = 0 , the volume of parallel hexahedron is zero, so
a1 b1
a2 b2
a3 b3 = 0 ⇔ α , β , γ are coplanar.
c1
c2
c3
Then we can get the conclusion that the linear equation which is through two points ( x1 , y1 ) and ( x 2 , y 2 ) on the plane is:
x x
y1 1 y2 1 = 0 .
x
y3 1
Then we can also get the conclusion that the equation of plane which is through three points ( xi , y i , z i ) (i = 1,2,3) not in the same line is:
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x
y
z
1
x1 x2 x3
y1 y2 y3
z1 1 =0 . z2 1 z3 1
Conclusion
Put geometric thinking into linear algebra teaching practice can reduce difficulty in understanding mathematical concepts, properties, and theorems. In the mean time, it helps students to understand their background, to stimulate their interest in learning, which will enhance their confidence to learn linear algebra, to ensure students lay at the university level a solid mathematical foundation.
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References 1. Guo, Y.: Merging Geometrical Thought into the Teaching of Linear Algebra. Journal of Yichun College 32, 186–187 (2010) 2. Yu, Z., Li, Y.: Linear Algebra and Analytic Geometry. Tsinghua University Press, Beijing (1998) 3. Min, L., Chen, X.: Researchful Teaching Case on Linear Algebra. Journal of Southwest China Normal University (Natural Science Edition) 35, 206–208 (2010) 4. How to Inspire the Students Motivation to Learn Mathematics, http://www.studa.net/xueke/070205/13240262-2.html 5. Liu, J., Wu, M.: Some Ideas on Improving the Teaching Method of Linear Algebra. J. Studies in College Mathematics 13, 13–15 (2010) 6. Teng, S.: Research on the Geometrization and Application of Linear Algebra in Teaching. Journal of Adult Education School of Hebei University of Technology 23(3), 23–28 (2008) 7. Xu, D.: Integrating Linear Algebra Teaching with Geometry Interpretation. Journal of Changzhou Institute of Technology 19(2), 72–75 (2006) 8. Wang, J., Guo, M.: The Cultivation of Geometrical Visual Should Be Strengthened During Linearity Algebra Teaching. Journal of Xinxiang Teachers College 17(2), 51–53 (2003) 9. Zou, J., Li, G.: Geometrical Methods in Teaching of Linear Algebra. J. North China Univ. of Tech. 10(2), 36–42 (1998) 10. Jaffe, A.: Ordering the universe: The role of mathematics. SIAM Review 26, 473–500 (1984)
Discussion on the Categorized Teaching of College Mathematics Yongli Zhang1 and Yanwei Zhu2 1
College of Light Industry, Hebei United University Tangshan, China [email protected] 2 Department of Mathematics and Information science Tangshan Normal University, Tangshan, China [email protected]
Abstract. The students are the subject of teaching, they must be divided into different types to train. In order to grasp the actual need of students, teachers must to do two surveys: First, investigation of mathematical basis and mathematics interest; Second, employment of students is analyzed. These different categories set for different courses. In the teaching program, we should open more than one direction and take into account the cluster positions and special positions. In the curriculum, the elective sections will be set in order to meet the individual needs of students. We must inspire students to generate upward of motives and behavior. By categories teaching, quality education was effective implemented and enable students to effectively triage, help students to further study after graduation or employment. On categorized teaching, teachers put forward higher requirements, so it will inspire teachers to raise the level of their business and further promote the teaching and research work. Keywords: Categorized Teaching, College Mathematics, mathematics teaching, practice Teaching.
Theory of Categorized teaching was from Confucius's "individualized". It is effective measures for the development of all students. American psychologist Bloom in the Mastery Learning pointed out that "many students achieved outstanding results in failure, the main problem is not lack of student intellectual ability, but because the conditions have not been appropriate and reasonable to help teaching caused" , "If there are the appropriate conditions for learning, most students will become very similar in the learning ability, learning speed, and further motivation aspects. "Learning conditions mentioned are that student’s learning to master the necessary conditions. "Classification of teaching" is to provide maximize "learning conditions" and "necessary to learn a new opportunity for the different types of students that". Combined with modern teaching philosophy is to teach all students. Math is a scientific, systematic subject and its internal structure and strict system of knowledge. So it must followed principles of the acceptability [3,4] . On chain of knowledge in mathematics, if previous knowledge isn't mastered, knowledge is difficult to accept the back. To resolve the basis of differences in student mathematics major issue that must be implemented classification of teaching.
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Concept and Objectives of Classification of Teaching
Based on requirements of quality education, Classification of teaching is to all students, recognition of student diversity, changing the traditional teaching model. In order to cultivate more specifications, multi-level talent, it takes the necessary measures [5]. Enthusiasm and initiative of learning are transferred by classification of teaching. So that students from "I study" into "I want to learn". Promotion of Learning was promoted from the root; by classification of teaching, quality education is effectively implemented and students are divided. It will help students' further education after graduation or employment. So there are many benefits. It makes all the students learning anything, learn a director, becomes the only available, the student-oriented education purposes are better reflected.
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The Conditions of Classification of Teaching
First of all, there are the full support of the school environment and corresponding system of protection. We are actively organizing classification teaching and implementing education policy and establishing a modern university. The personnel's training is our goal. Its mode will be reform. Strengthen the teaching staff, structure of academic disciplines. We will increase investment in teaching and research and improve school conditions. Our overall requirements are to strengthen the foundation, personality development, improve the quality. The basic objectives are to foster innovation and practice. Optimize the
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structure of courses, update teaching content, teaching methods and teaching methods, and strengthen teaching management, improve teaching quality [6,7,8]. Teaching in the syllabus and teaching programs related to management, teachers, teaching arrangements, the progress of teaching and teaching assessment, classroom management and other aspects, need to multi-coordinated action, therefore, it should be as "systems engineering", do a good job of teaching the supporting category reform. 4.1
Credit and Academic Structure Reform
Complete classification of credit is an ideal vehicle for teaching. On same Semester there are the different categories of students. Elective courses are also different with different access to credit, so that the students, both fair and science, and help mobilize the enthusiasm of the students. Full credit should be combined with flexible education system; students can graduate early because of enough credits. 4.2
Teaching Administration
Teaching will to break the traditional management mode of teaching. The original the teaching of management will be reformed. First, from a unified curriculum for the different categories to determine the curriculum change; second, unification progress of teaching by the progress of teaching to non-uniform change; third, the uniform examination content, uniform appraisal standards to multiple assessment content, assessment standards change, and so on. 4.3
Student Management System Reform
The original static administrative classes are became into dynamic classes, which increased the difficulty of student management, student management will also raise new issues. As same time the assurance measures of teaching are established. They are implemented simultaneously with the classification. The incentives will be introduced to stimulate student interest, curiosity, and curiosity, responsibility, self-motivated in teaching. We are good at finding bits of student progress and provide good learning conditions and the learning environment, conducting block point, the creation of the chance of success and inspire students to produce upwards of motivation and behavior. Secondly, the classification of teachers teaching a higher level of demand In the classification of teaching, teachers should design to adapt better to a certain type of learning activities of students and choose appropriate teaching methods, highlighting the different teaching focus. Classification of teaching requires teachers to pay more than the normal work of teaching. Teachers need develop syllabus and different teaching objectives, according to different types of knowledge, the future direction of development for different teaching objectives. Teachers choose the appropriate degree of difficulty of the materials, prepare of different teaching contents and related information, respectively, to design
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appropriate classroom activities, in the difficulty of teaching content, breadth, etc. to adapt to different types of student learning, needs.
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In the Practical Implementation
Since the actual situation of college students vary widely, college students should be combined with psychological needs, personality, hobbies, etc., a reasonable classification of students and positioning for the future to develop a realistic career direction and channel. Accordance with the syllabus requirements, combined with the study section of the actual needs and our school, science and engineering undergraduate mathematics curriculum points, finance and economics, humanities and law class three categories set up. We should make for different types of training programs to different students. The teaching team must to make for different training objectives and design different training programs to ensure training goals. From the teaching standards, monitoring, teaching and research aspects to consider, specifically targeted at the teaching situation, our higher mathematics is carried out categorized teaching. The higher mathematics into four categories: Advanced Mathematics (a) 190 hours. For professional: physical, telecommunications, computer science and technology, automation, machine since, civil engineering, textile, garment engineering and other professions. Advanced Mathematics (b) 120 hours. For professional: project management, information, business management, international trade, accounting, chemistry, medicine and other professionals. Advanced Mathematics (c) 85 hours. For professional: management of public utilities, scientific management, biological and other professionals. Advanced Mathematics (d) 68 hours. For professional: Sports, care professional [9,10]. Linear algebra is divided into two categories: linear algebra (science and engineering), linear algebra (administered by the class). Probability and Statistics is divided into two categories: probability and statistics (science and engineering), probability and statistics (Economics and Management). If we can smoothly implement the classification teaching, we need innovative teaching organizational model and the reform of teaching methods. Teaching is one of the major contradictions: students of similar ability in learning mathematics are quite different; the requirements of students of mathematics are quite different. To solve this problem, Mathematics teaching in the classification based on the further implementation of different levels of teaching thinking and practice. The overall guiding principle is: in the same category of university mathematics teaching, the principle of voluntary students, divided into higher demand, higher demand and the basic requirements for three levels. Ability to learn and to have a higher demand for math students in our school can receive informative, systematic, more in-depth teaching of mathematics; less capable of learning, there is no high demand for math students in the these students within our school will set the basic requirements for college math.
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Concrete can be used the following approach: (a) we have prepared a syllabus to the course; syllabus (mainly for basic requirements); to materials, according to the syllabus, teaching proposal writing, teaching suggestions in the book to set the basic requirements made necessary basic skills. (b) If students have desire to study, we should active learning opportunities and learning conditions. Such as math-related seminars can be organized in order to improve our students of mathematics. Organization "colonel Mathematical Competition" training for the students to participate in the National Mathematical Contest does counseling. (c) In order to improve the student's ability of use analyzing and solving practical problems, we organized the school of mathematical modeling mathematical modeling training and competition each year. Winners were selected from the national team to participate in the International Mathematical modeling Mathematical modeling competitions and games. Levels of teachers teaching mathematics is to solve the difficult to teach mathematics difficult to learn an effective way, hierarchical teaching needs the support of school leaders and relevant departments, hierarchical teaching is based on a wide range of students. Reform of teaching methods is imperative. Mathematics teachers currently overloaded with work, lectures heavy workload, the workload change jobs more. Teaching contents, class conflicts are very prominent in this small, but the teacher or the equivalent time on topics writing, writing definitions, and theorems on the class blackboard. Repetition operations also occupy a lot of teaching time. This reduces the amount of information teaching. Therefore, computer-aided mathematics teaching is imperative.
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Categories Teaching Mode of Assessment Methods
Good appraisal system will help many types of training qualified personnel, establish a classification of teaching requires a wide range of institutions of higher education evaluation system, the students score and qualitative evaluation of the implementation of both quantitative and theoretical knowledge, expertise and skills assessment test simultaneously to adapt to different types of students of different assessment, truly reflect the student's range of knowledge and skills to adapt to the human resources needs of different markets. 6.1
Design a Variety of Assessment Criteria
Uniform standards of assessment: For all categories of students must master the basic content can be designed uniform standard of assessment methods, assessment of all students must master the skills and knowledge points. Differences in the standard assessment: on different levels, different types of students with different design standards for the assessment.
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Design a Wide Range of Assessment Forms
Writing of assessment: In addition to the traditional written examination papers, but also to take papers, study notes and other written forms of assessment. Research assessment: teachers can be the subject layout technology class, ask students to learn according to technology research and, based on research results and progress of a given value, this method could be integrated in the learning test, the ability to stimulate students to study, so the more appropriate in research talent. Display of assessment: Students participate in math competitions through training, field-grade students participating in school mathematics competition organized and the Mathematical Contest in Modeling, the achievements of the students to give some extra point’s bonus. Process of assessment: the process of learning all aspects of the comprehensive performance assessment: the usual attendance, organize class notes, class discussions, job performance, activities subject results, performance, and so demonstrate learning outcomes, and promote students of all abilities to develop, applies to all types of students assessment.
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Conclusions
In short, classified under the assessment of teaching must be teaching goals, no matter what kind of assessment methods, the objective is to develop students self-confidence, mobilize the enthusiasm of the students, to promote the development of student ability. Note that the classification of teaching is not classified as a category, classification teaching must still implement the "Talent Education" new ideas, the majority of students in the "higher education" on this platform and fully develop their initiative and creativity, their develop training to adapt to modern social and economic development needs of the application type, suitable for high-quality mathematical research and mathematical education of qualified personnel. Acknowledgments. This project was supported by the Science Foundation of Hebei United University (qd201007) and teaching and research to guide the project (qgjg201019).
References 1. Wan, L.: Level-division Education of Mathematics Teaching. Journal of Wuhan University of Science and Engineering (2010) 2. Jiang, C., Wang, F.: Practice and Significance of Level-division Teaching in College Mathematics Teaching. Continue Education Research (2009) 3. Mu, L.-h., Li, Y.: The Research and Study of Gradation Teaching of University Mathematics. Heilongjiang Researches on Higher Education (2005) 4. Wu, B., Han, X.: Research on Stratified Teaching for Higher Mathematics Teaching. Journal of Chongqing University of Science and Technology (Natural Sciences Edition) (2010)
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5. Li, B., Cui, Q.-f.: A Probe into Hierarchical Teaching in Higher Math Course of New Universities—An Example of Anyang Normal College. Theory and Practice of Education (2010) 6. Yang, J.: An Exploration on the Stratified Teaching of the Math Class in the Technical Secondary School. Journal of Tianjin Institute of Financial and Commercial Management (2010) 7. Xiang, H., Wang, J.: Research and Practice of Multi-level Teaching in Basic Mathematics Lessons. Journal of Xiangnan University (2011) 8. Wang, J.-h.: Research and Practice of Mathematics Modeling Thought Integrating Higher Mathematics Teaching. Journal of Xiangnan University (2010) 9. Ren, Y.-l., Chen, Z.-l.: Multi-level practical teaching of the advanced mathematics. Journal of Shijiazhuang Vocational Technology Institute (2011) 10. Liu, T.: Stratified Teaching of Higher Mathematics. Value Engineering (2011)
Block-Based Design ERP Curriculum Teaching Yuesheng Zhang School of Management, Xinxiang University, Xinxiang 453003, China [email protected]
Abstract. ERP (Enterprise Resources Planning) is a new course. This paper analyzes teaching reform and practice of ERP course from the teaching aim, teaching content, teaching organization, teaching methods and evaluation methods. Research that ERP course include of business simulation, software simulation, theory explanation and project training, determine the course points by professional properties and organize the teaching module by concept. It lists the suitable for the ERP course of online discussions, case teaching, experience and open teaching -four kinds of special teaching methods, and summarizes examination through the existing assessment and comprehensive evaluation committee examination of practical experience and ability to experience. It is necessary for enhancing teaching effect to choose suitable course content and teaching methods. Keywords: ERP course, teaching, reform.
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Introduction
ERP is the Enterprise resource Planning system, is the Enterprise informatization means from MRP, MRP , after nearly 30 years development achievements, the 1990 s, to the Enterprise management environment to the economic globalization, market internationalization, agile response information change, the traditional management ideas and methods can't better suited to the requirements of the development of the Enterprise, in such a situation arises, an idea of management and management tools. ERP system is based on the current advanced information technology, network technology, computer technology foundation, the integration of modern management thoughts, involving enterprise management each link a management platform. ERP reflects the age of the knowledge economy enterprise resources to reasonable allocate request, to become the enterprise survival in the information age, the cornerstone of development. ERP system management thinking is being recognized by domestic enterprises, ERP implementation of projects of the informatization of Chinese enterprises has become an important job. With ERP system in the popularity of the enterprise application, some universities economic and management specialty and the computer kind professional will also introduce into the teaching system, as practice teaching reform of the university training course. ERP System is not just a MIS (Management Information System) System, also is not only enterprise Management and information technology, the
simple combination, but contains various Management technologies to standardize enterprise Management of a Management mode, Management thought. Therefore, this course teaching can't simply re-broadcast computer application course, management information system course or enterprise management course teaching model. In this paper the author in teaching in ERP personal experience as the basis, from teaching aim, teaching content, teaching organization, teaching methods and evaluation methods, analyzed the aspects of teaching reform of ERP system and practice.
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Overall Thought and Course Properties
ERP is a set of management thought including the multiple information technology and computer technology. Its teaching and research, not like other course just a teacher, and at most two teachers can independently teaching, it needs a multi-disciplinary, interdisciplinary teaching team can complete the whole of the teaching task. It is our school was established during the staff room, ERP by each of the members of the professional backbone teachers composition, computer software, network, applications of teachers, in a planned way management, financial accounting, e-commerce, logistics supply chain, the production management, the information management of teachers, also hired ERP software vendors and enterprise executives and engineers as our part-time teachers. In the teaching, according to the different requirements for professional training courses, according to the different position and professional, points module, the different on the form of organization and teaching methods. This course is a computer application kind professional practice course, finance, and management specialty is the core of the course and experiment courses.
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Teaching Content
ERP courses include of Enterprise simulation, software simulation, theory explain, project training -four parts. Enterprise simulation refers to the simulation enterprise management, also called ERP simulation, this part of sand table with ERP sand table tool often finish, sand table marked on the main function of the enterprise operation department, work flow and management rules and so on, by the students as the main function of the enterprise management personnel department personally run a virtual entity management enterprise. This part is the main task of the first let students from perceptual knowledge on ERP system, understand the basic structure of ERP brings to the enterprise benefit; Second is to get students to master the basic data of ERP operation environment, such as plan management, materials management, workshop management, procurement management and financial management, etc. Theory is part of the enterprise management in enterprise simulation based on summary ERP related concepts and principle, functions and development, and other basic knowledge, enables the student to master from the reason of ERP, can use the related theory basis "self-study + homework + explanation" instruction method of complete. In the teaching of the course of ERP software usually include financial management, supply chain management (purchasing management, sales management and inventory
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management), production management, human resources management, the main module. Actually, you can choose teaching content according to the nature and professional training requirement. For example: accounting major objective orientation in mastering the operation with ERP financial module analysis; Human resources professional emphasis on human resources module of study and practice. In Xinxiang University, information management specialized ERP teaching goal for: to understand the concept and principles; ERP Skilled operate ERP financial module and supply chain module; master ERP system installation, basic maintenance and simple second development; to be able to deal with enterprise actual business. Project training before study is on the basis of three parts, the staff room provide real enterprise environment, let the students to use sand table and ERP software tools, in view of the different vocational character alone our tasks, and together to reach the enterprise the management goal.
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Teaching Organization
According to the content of the course of four parts ERP teaching requirements are different, can use different organization form. The study of the theory and software, can according to their previous lecture part class set organization teaching. Enterprise simulation and project practice part requires much professional joint participation, group to implement education. In each group, different students in a different role, common management a enterprise. Teaching, students can freedom group, but for a group of students in different composition, cooperate to complete the entire enterprise management, production and management of all work, beginning to financial budget, the final to submit the financial statements. Students in the operation of an enterprise, not only in the process of understanding the ERP of principle and thought, but also from other students learn the professional knowledge and skills of the outside, and improve the students' comprehensive ability and quality management, and to cultivate the students' team consciousness and teamwork spirit. In addition, in the software interpretation and training part, the author suggest project management professional teachers and by computer professional teacher organized teaching, so from each other, cross penetration. Management professional teachers teach ERP principle, management ideas and enterprise working process, the computer professional teachers teach ERP system structure and guidance system application and data maintenance.
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Teaching Method
ERP as a new course, the traditional teaching methods and experimental method has not good to adapt to the teaching requirements. In the course of teaching, as leader of the teachers teaching, must explore suitable for this course teaching method. The author through the long-term teaching practice summarized the following several kinds of teaching methods, combined to better adapt to the need of teaching the course.
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Case Teaching Method
Usually the teaching material is boring ERP course, teachers need in the process of teaching continuously string into related cases to swap, so that the course with strong attraction, let the students to turn a negative accept knowledge for positive to absorb the knowledge. For example, we in the teaching process often to provide students with ERP implementation of the success of the business case and implementation of failure, let them their enterprise case analysis enterprise implement ERP condition, the influence of success and failure. 5.2
Online Discussions and E-Learning System
The teaching method is established for the ERP course learning website, open communication BBS, ERP association was established, opened ERPQQ discussion groups, let the students study the problems existing in the idea and successful experience, sent to the website BBS about, in QQ group of online communication, brainstorm, learn from each other, form a kind of teachers and students of interactive teaching environment. At present, our school has "ERP and information society" and "ERP BBS" and called the "base" of ERP QQ group, etc. In addition, we also held nearly two years successful ERP career event, not only impelled the students obtain employment, but also understand the demand of the enterprise to broaden the channels. 5.3
Experience Teaching Method
The teaching method is mainly used in enterprise management simulation and project practice, part is that let students in the simulation of the enterprise as a different enterprise post role, form a team himself runs a enterprise. Not told, but personally experience how to business enterprise, how to do his own work and how to work in the coordination of true to the requirements of the workplace, with management staff to the success of the theory of "hero". This method has a strong participation, interactive and actual combat sex, competitive, and the experience, let students "studies in the joy", "participate in learning", "in the error of learning", "practice middle school, after learning with". Such teaching way so that the students can experience real in the learning process, as to be in enterprise experience, error correction of enjoyable to learn to management knowledge, management skills, to improve students' management ability, cooperation consciousness are actively significance. Sand has the competitive, simulation of interest, practicability and actual combat sex is other class teaching mode incomparable. 5.4
Open Teaching Method
In 1921 the British Neil advanced the concept of open teaching, he advocated "students learn in the game." The modern "open" teaching, meaning more rich, should be should be comprehensive and perspectives. First it is the opening up of the education content. The new knowledge increases, education content should update mechanism, to adjust the
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supplement, still should focus on front, facing the practice. Second is the opening of the teaching process, to break the starting point and by the end of the enclosed for conclusion teaching process. The teaching purpose can not church solution and master the conclusion, it explores and solves problems in the process of thinking and development ability, exercise is to cultivate the actual ability to deal with problems. Education is the open space again. Instead, the school break instead of the education of the space, the classroom should be extended to the society, to strengthen the teachers and students with practical business units to the communication between contacts. Through the "going out, please come in" means, realize the teachers and students and social practical business department of the interactive cooperation between, so as to improve the quality of teaching and the level, and improve students' comprehensive quality. The so-called "please come in" is to have good ERP knowledge trainers and enterprise management experts and engineers of the related to school to please, give teachers, students do training guidance. The so-called "going out", it is to make teachers to enterprise management software company to further study, to participate in training, update knowledge; Is to make the teachers and students to brother institutions communion and study, a joint project training and leading the ERP sand table, realize in the competition from each other; learning Is that let students to the enterprise to practice, the students to master relevant knowledge and practical business, the associated study achievement verification, do theory knowledge and the organic integration of the specific affairs. 5.5
Assessment Method
Students of the course of ERP, has not a examination papers, an experiment report could solve the question way, to take means overall performance. Enterprise analog part, the proposal by 2 ~ 3 different professional teachers who composed appraisal committee, let the students for the inspection members and tutorials, appraisal committee derived by observing deductive process and students examine defense situation. Examination committee can not only simple derived according to the students' theoretical level and the judge operation ability, to the virtual organization's role and function, as well as the cooperation spirit in the team work attitude and comprehensive evaluation. The traditional theory part can be searched, examination mode. Software operating part can use case, this part of the computer operation test can let students use after school time to finish. We practice is to be on the final exam before 3 weeks to students extend operation data, let the students in 2 weeks after school time to complete, and submit individual account to cover packets. Project practice, we generally on graduation practice training, finished to training reports as assessment basis. The experimental teaching has long been the school as classroom teaching auxiliary and added, but ERP course teaching was different, it composed by subject, the teachers and students in different combination, using kinds of complete teaching method and unique organization form to a door new course. The course of introduction, is to teaching way and the reform of teaching contents and innovation, will become the
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economic management discipline in the practice of teaching reform of university management professional breakthrough talent training mode reform ideas and provide new mode.
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Conclusion
The teaching methods suitable for different teaching content, according to the teaching content and students’ learning choose teaching method. Limited to the limitation of length, some ERP teaching in common use in the traditional teaching method in this no longer tautology. At the same time as the teaching technology and teaching means of development, the future there will be more suitable for more updates method of teaching needs to be we continue to explore.
References 1. Ji, X.: ERP principle, application and practice course. Lixin accountant press (2008) 2. Wang, G., Gui, H.: ERP of principle, implementation and case. Electronic Industry Press (2003) 3. Yanqi, Guo, Y.: ERP course teaching cit. Journal of Jiaxing University (2005) 4. Open Teaching Method, http://www.3edu.net/lw/7/lw_13225.html 5. Yangjin: Computer fault fine solutions, vol. 900. Cases of Ocean Press (2002) 6. Zhang, Y.: Security scanning technology. Tsinghua University Press (2004) 7. The computer assembly and maintenance introductory and improve. Tsinghua University Press (2005) 8. Xiong, Q.: The computer skill training. Beijing Kehai Electronic Publishing House (2005) 9. Chen, Y., Song, P.: ERP tutorial. Tsinghua University Press (2009) 10. ERP online learning, http://www.kingdee.com/ 11. http://learning.ufida.com.cn/ 12. Fan, C., Zhang, P., Liu, Q., Yang, J., Xi, W.: Research on ERP Teaching Model Reform for Application-oriented Talents Education. International Education Studies 4(2) (2011) 13. Hackney, R., McMaster, T., Harris, A.: Using cases as a teaching tool in IS education. Journal of Information Systems Education 14(3), 229–234 (2003) 14. Chen, G.: On the Development of the ERP Sand Table Teaching and Cultivation of Practical Talents. Journal of Changchun University of Science and Technology(Higher Education Edition) (2007) 15. Yu, Y.-q.: Introducing ERP Sand Table Simulation into Economy and Administration Teaching Reform. J. Experiment Science & Technology (2006) 16. Zhu, Z.-q., Wang, Y., Wei, Y.-x.: Application of ERP Implementation Process Board-based Simulations System in Experimental Teaching. J. Research and Exploration in Laboratory (2007) 17. An, F., Sun, H.-x.: ERP sand table simulation training and cultivating students’ comprehensive qualities. Journal of University of Science and Technology Liaoning (2009) 18. Shen, W., Wen, W.-q.: Discussion on Operations Research Curriculum Experimental Teaching Method. J. Research and Exploration in Laboratory (2009) 19. Cheng, S., Zhang, D., Cheng, X.: Exploration and Application of Digital Circuit Course Based on Project-driven Method. J. Computer Study (2010)
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20. Liu, C., Wu, D.: Application of Project Teaching Method in the Course of Analog Electronic Technology. Journal of Changsha Aeronautical Vocational and Technical College (2010) 21. Li, J., Huang, J.: A Practice on Electron CADTeaching Methods. Journal of Guangdong Industry Technical College (2010) 22. Li, Z.-c., Qiao, J.-t.: The Research of Software Engineering Course Teaching Method. J. Computer Knowledge and Technology (2011) 23. Xiao, N.: The Research of Improving Teaching Effect on VB. NET Program Design. J. Computer Study (2011)
Teaching Computer Graphics in Digital Game Specialty Hui Du and Lianqing Shu College of New Media, Zhejiang University of Media and Communications, Hangzhou, China {huidu1129,shulianqing}@163.com
Abstract. Computer graphics is an important specialized course in digital game development. Traditional teaching of computer graphics is not very fit for the students of digital game development specialty. Based on combining the character of digital game specialty with that of computer graphics, in this paper we analyzed some problems existed in daily teaching of computer graphics, discussed some methods to solve the problems.The methods involve in the aspects of teaching contents, teaching means and experiment teaching. One year’s experience of teaching practice shows that these discussed methods produce obvious effects on improving quality of daily teaching. Keywords: Digital game development, computer graphics, teaching practice.
We summarize the existing problems in our daily teaching by using a questionnaire survey. One problem occurs between the teaching objective and students’ expectation. In order to arouse the interest of learning, teachers usually introduce some latest research works from several top international conferences such as SIGGRAPH, and some film effects or game examples that computer graphics is applied in the first lesson. Besides, there are many various color figures in many computer graphics books. Another is the problem of the textbook and the specialty orientation. The contents of most textbooks of computer graphics, which include graphics hardware, 2D raster graphics and realistic graphics, are almost identical and these books usually introduce the mathematic idea of graphics algorithms in detail. Table 1. The contents of computer graphics in game development
Components Geometric modeling 3D graphics display
Realistic graphics
Main contents (1)Geometric modeling and display of plane object (2)Geometric modeling and display of surface object (1)Geometric transformation of 3D graphics (2)3D clipping (3)Projection change of 3D graphics (1)Illumination model (2)Material, texture generation (3)Shadow generation
The final problem we summarized is between the theory teaching and the experiment teaching. In our school, the course before teaching reform includes 54 hours’ theory course and 18 hours’ experiment course. Only few students could implement the experiments such as transformation of 3D graphics, texture mapping and setting lighting in limited experimental course.
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Discussion on Teaching Reform
The new teaching methods are introduced based on above problems to be concerned. The basic idea is that we try to improve the teaching quality of computer graphics course by reforming teaching contents and ways, experiment teaching and evaluation method. 3.1
Teaching Contents Arrangement
We clear the relationship between the contents of computer graphics and digital game development. Then, we modify the important points and teaching contents of traditional teaching to fit the training objectives of digital game specialty. The teaching points of computer graphics course in digital game specialty are 3D computer graphics and realistic graphics, so we reduce the contents of 2D raster graphics in daily teaching.
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We summarize the relationship between the contents of computer graphics and game development. The main teaching contents of computer graphics in digital game specialty are shown in Table 1. In our school, digital game specialty uses Donald Hearn and M. Pailine Baker’s Computer Graphics with OpenGL (Third Edition) as the textbook of computer graphics course. This textbook assumes readers have no prior familiarity with computer graphics which conform to students’ status of digital game specialty and presents basic principles for design, use, and understanding of computer graphics systems. It combines the discussions of three-dimensional and two-dimensional computer graphics methods[3]. More important, it includes an extensive range of programming examples to illustrate the use of OpenGL functions and presents a large number of complete C++ programming examples. Table 2. The investigation result of web course teaching
Evaluation items Very good Attitude toward web teaching 35(68.6%)
Good 9(17.7%)
Ordinary 5(9.8%)
Bad 2(3.9%)
Building of web site 37(72.6%) Teaching resource of web 40(78.4%) course Teaching effects of web course 39(76.5%)
8(15.7%) 6(11.8%)
4(7.8%) 4(7.8%)
2(3.9%) 1(2.0%)
8(15.7%)
2(3.9%)
2(3.9%)
In addition, the fundamental knowledge of some algorithms and related contents closely with digital game development, for instance, collision detection, 3D model animation, kinetics and game scene management, are introduced into our teaching contents. These contents are not involved in most current textbooks of computer graphics. 3.2
Improving Teaching Methods
Single theory teaching can’t draw students’ attention no matter which grade they are in[4]. Zhou et al.[9] propose an teaching approach by presenting a three dimension (3D) tree modeling case. We use the following methods to excite students’ learning interests, make them understand the application value of learning. Indeed, with its intrinsic targeting of images and animated sequences, computer graphics education is ideally suited for applying multimedia[8]. We use multimedia technologies effectively in the theory teaching. Specifically, we make Flash demos of 18 classic graphics algorithms in order to help students to understand the basic concepts of the algorithms. These Flash demos simulate the operation flows of the algorithms. These demos and animations include the contents of raster graphics, hidden-surface elimination and realistic graphics. We usually play these demos for students after the mathematical points of the algorithms are introduced. Besides, we use network technologies to extend traditional teaching. Web course is an important way to improve the quality of teaching. We build a site of computer graphics by using BlackBoard
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platform. This site includes teaching source module, case module of game development, online exam module, work submission module and interaction module and so on. Teachers may prepare their lessons, give assignments, correct students’ online assignments, release notes and discuss with students based on the web teaching platform. Students also may browse the teaching site in their free time and selectively learn the knowledge which they do not master in theory teaching. This web course lightens students’ burden. Meanwhile, students browse the game demos and videos that are the application of computer graphics in game development, which improves students’ learning interest. We carry out some investigations in order to evaluate the effect of our web CAI system in computer graphics teaching, we regard 51 students of digital media technology specialty as respondents and the investigation result is shown in Table 2. The results of investigation show that the attitudes of most students toward web course teaching are positive. Most students think that the contents of web course are plausible, the site extends the knowledge of theory teaching of computer graphics and they may learn some the latest research focuses of computer graphics. Table 3. The contents of computer graphics experiment
Experiments name Graphics programming environment
Main contents (1)The flow of OpenGL programming (2)The use of the GLUT (3)The rendering pipeline of OpenGL 2D graphics filling (1)The flood filling algorithm (2)The scan line polygon filling algorithm Graphics transformation (1)Translation, rotation and scale of 2D and 3D graphics in OpenGL (2)Comprehensive implementation of transformations Rendering of curve and surface (1)The rendering of quadratic curve and quadric (2)The rendering of Bezier curve and surface (3)The rendering of NURBS curve and surface 3D viewing (1)3D projection in OpenGL (2)3D clipping in OpenGL Illumination model (1)Lighting setting in OpenGL (2)Local illumination model (3)Whole illumination model (4)Shadow generation Texture generation (1)Texture setting in OpenGL (2)Loading texture images and texture mapping Practice project (1)Using acquired knowledge to solve a large work
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Case teaching is also introduced into the theory teaching. We leave ten minutes to introduce the current research focus and play related research demos in each lesson. These cases are selected in several top international conferences and journals such as I3D, SIGGRAPH and game developer. Before the teaching of cases we should know where the relevant background and knowledge cases which are mentioned locate in the whole knowledge system[6]. 3.3
Experiment Setting
It is very necessary for the students to consolidate the knowledge through computer graphics experiments. As previous mentioned, 3D computer graphics is one of the important contents of computer graphics in digital game specialty. OpenGL and Direct 3D are two excellent graphics interfaces to be chosen, but the latter is only for Windows systems. Therefore, we introduce OpenGL into our computer graphics experiments, that is, all experiments require the environment of VC++ 2005 and OpenGL. OpenGL is a high-performance 3D graphics standard and have strong power in the 3D aspects. For avoiding the complex windows and input interactive function in windows programming, we choose the OpenGL Utility Toolkit (GLUT) to simplify students’ programming tasks. This allows students to put more effort into the contents of graphics. The experiments include two modules: verification experiments and practice project. The contents of the experiment course are shown in Table 3. The verification experiments are to let students go through basic knowledge and basic skills by programming[5, 10]. Figure 1 and Figure 2 are three experimental results of implementing Z-buffer, scanline z-buffer and raytracing algorithms by our students, respectively.
Fig. 1. Two implementations of Z-buffer algorithms by our students.(a)is the implementation of Z-buffer algorithm. (b) A student’s scanline Z-buffer implementation system. Users can rotate the model in both scene windows interactively by using the keyboard.
The last practice project is a work that requires students to integrate learned knowledge to complete a task. It is a comprehensive programming project that aims to strengthen the ability of students applying learned knowledge comprehensively on solving a new problem and improve students’ programming ability.
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Fig. 2. A student’s experimental example of raytracing algorithm
3.4
Evaluation Method
We use comprehensive evaluation to give the final grade of each student. Comprehensive evaluation includes three portions: final theory exam, experiment and practice project. We increase the proportion of practice portion to emphasize the importance of practical ability.
4
Conclusions
We have presented and practiced teaching reform of computer graphics course in digital game specialty. One year’s experience of teaching computer graphics using new methods shows that the teaching reform has improved the quality of teaching and the students’ ability to understand the basic concepts and solve the related graphics problems. Although we reform the teaching of computer graphics course in digital game specialty, it also has reference value for other related specialties. For the future work, we may incorporate ideas from other computer science disciplines, such as theory of computation, into programming projects[7]. Besides, motivated by the teaching system proposed by Lu et al.[11], we also try to develop a new experimental teaching system for our computer graphics course, which allow the students to design programs, submit the experimental data and pictures to database. Acknowledgments. This work is supported by Scientific Research Fund of Zhejiang Provincial Education Department (Y201016221 and Y200907390) and Experimental Teaching Demonstration Center of Zhejiang Provincial Animation and Digital Technology.
References 1. Jordi, L.P., Pau, M., Javier, E.P.: Computer Graphics: From Desktop to Mobile and Web. IEEE Computer Graphics and Applications 31(4), 94–97 (2011) 2. Jiang, Z.D.: Computer Graphics Teaching and Practice. Computer Education 3, 10–13 (2006)
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3. Donald, H., Baker, M.P.: Computer Graphics with OpenGL, 3rd edn. Prentice Hall (2003) 4. Li, L., Huang, Y., Gu, Y.S.: Research and Discuss in Teaching of Computer Graphics. In: International Workshop on Education Technology and Computer Science, p. 22 (2009) 5. Yuan, G.W., Xu, D.: The Experience and Discussion on The Reform of Computer Graphics Experiment. In: The 2nd International Conference on Education Technology and Computer, pp. 178–181 (2010) 6. Han, H.J., Zhang, C.M., Feng, J.F.: Research on Several Questions in CG Case Teaching System. In: Proceedings of International Symposium on IT Medicine and Education, pp. 193–197 (2008) 7. Gousie, M.B.: Teaching Computer Graphics in A Small Department. The Journal of Computing Sciences in Colleges, 194–202 (2000) 8. Reeth, F.V., Coninx, K.: Using Networked Multimedia in Computer Graphics Education. In: Computer Networks and ISDN Systems, pp. 2065–2073 (1998) 9. Zhou, J., Ye, M., Huang, C.L.: Reform of Computer Graphics Teaching Method. In: International Forum on Information Technology and Applications, pp. 222–225 (2010) 10. Yuan, G.W., Xu, D., Zhao, Y.: Teaching Reform of Computer Graphics Experiments. In: 5th International Conference on Computer Science and Education, pp. 658–662 (2010) 11. Lu, L., Wang, L., Yang, Y., Gui, Y.: Research and Development on Experimental Teaching System for Computer Graphics. In: Second International Conference on Information Technology and Computer Science, pp. 402–404 (2010)
Discussion of Some Problems in Statistical Teaching* Yan Gao1,**, Xiuhuan Ding2, and Linfan Li3 1
School of Science, Hebei United University, Xin Hua Street 46, Tangshan, 063009, Hebei, P.R. China 2 College of Mathematics and Information, Zhejiang Ocean University, Zhoushan 316000, Zhejiang, China 3 People’s Armed College, Hebei University, No. 42 Ping’an South Avenue, Shijiazhuang 050061, Hebei Province, China [email protected]
Abstract. This article mainly discusses some problems encountered in statistical teaching for general institutions of higher learning, which include the consistency for students’ learning and the big difference in level between major courses, some teachers use easy textbooks and some use difficult textbooks. To solve these problems, we give out some advice. First, when we encounter old knowledge in learning new knowledge, we should remind the students of the old knowledge, so the students can remember the knowledge more deeply. Second, we should form a statistical teaching team, discuss the difficult degree and the objectives for statistical teaching. The method will be useful for improving the students’ level in major course, so we can make the statistics subject developing more rapidly. Keywords: mathematical statistics, data analysis, knowledge applied talents.
1
Introduction
I have been a mathematical statistics teacher for nearly four years. Recently I am always thinking about the specific characteristic, development and the application for mathematical statistics subject. For a long time, statistics is mainly in forms for reporting statistics, statements and report in China. When people ask for my occupation, I tell them I am a statistics teacher, they think statistics is nearly the same as accounting, they even don’t know what the statistics is used for, statistics major is not exist in mathematical school in many colleges, some colleges have undergraduate program in statistic but don’t have the graduate students, or some colleges statistics graduate students is enroll as mathematical students, and the number of the Doctor selects stations is very small. Above all, the development of the mathematical statistics is far not enough. *
Supported by the Foundation of Zhejiang Ocean University (No. 21065013009). Corresponding author.
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There are many scholar researching the development of the statistics, Hengtong Zhou discusses the rationality of application of mathematical statistics to analyzing social and economic problems and explains what trans-science analysis across mathematical statistics and economics is and the status of traditional social and economical statistics in the system of statistical subjects. Wei Xue brings forward a framework of statistical application first, and then analyzes the current trend of statistical study and statistical application based on this framework. Finally, she points out that the research of statistical methodology will become one of the important aspects of Statistical Study in the future. In modern society, lots of talents in statistics who can process mass data are need in many fields, e.g.: Market research, securities analysis, Risk management and so on. People rarely think of the graduate students of statistics have the ability and superiority, so what we should do is to make people know that the statistics graduate students can complete the work very well and we must be able to educate the students to have the abilities. We are trying hard to reach the goal, but we often meet with problems, in which some concern to teachers, and some concern to students.
2
The Main Problems in Statistics Teaching
In recent years, the statistics developed very quickly, many school set Statistical Specialities which we can see from table 1. In Hebei province, there are 7 universities which set the major of statistics during the ten years, while Jiangsu increase 15, much more than Hebei. Table 1. The Number of Statistical Specialities for each province in 2002 and 2011
Universities in Some provinces have no Statistical Speciality in 2002, but now they have, we can see from table 2.
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Y. Gao, X. Ding, and L. Li Table 2. Number of Universities which Set Statistical Speciality during Ten Years
Province Guangxi Hainan
2011 5 4
Province Tibet Qinghai
2011 1 1
Province Ningxia
2011 1
Data come from: http://gaoxiao.sooxue.com and: http://www.eol.cn. The universities in eastern area have more Statistical specialities than other area, we can see it from figure 1.
Fig. 1. The Number of Statistical Specialities for each province in 2011
Note: 1 to 11 denote the provinces in eastern area, 12 to 19denote the provinces in middle area, 20 to 31 denote the provinces in western area. Because many Statistical Specialities are set recently, so there must be many problems in statistical teaching. I think statistics is only a methodology, which is the same as English and Computer Technology. It analyzes the data of real background based on mathematical knowledge, and provides the result in accordance with the real background. Economical statistics is
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come from the application of the statistics in economy, so as the enterprise statistics, management statistics and industry statistics. Mathematical statistics is located in mathematical school, which is more emphasis on the application of the mathematical knowledge in the researching the statistical methodology. We also research the real problems by statistical tools, in order to improve the statistical theory. If we want to learn the Mathematical statistics well, we must master the Mathematical knowledge well, especially Mathematical analysis and higher algebra. As we all know, the study of math is very difficult, so the study of Mathematical statistics is more difficult. I found some problems in teaching. First, there is no consistency in the students’ learning process, most of the students in statistics major don’t know that they have to learn mathematics before learning major course, they don’t like the basic mathematics courses, because they think the formulas and theories are too much and too hard to learn. When I teaching them the major course, I found they are interested in the application of the course, but they can’t learn the method and the theory very well because of the weak foundation, so that they can’t analyze the real problems well. Second, many students don’t know how to use the knowledge they learned before to the new knowledge. For example, I used to tell the students that statistic can be described by samples in linearity in their sophomore year, but the next year, when they learn Analysis of regression, we need construct a statistic, the students don’t understand why I use examples to express the statistic, I know, they have forgotten the knowledge learned before. This problems is general faced with students, they will forget the knowledge very soon after the final examination. And they don’t know that they will use the knowledge in the future learning. Third, there is big difference in level between major courses, as we all know, the statistics is divided into mathematical statistics and other statistics, the textbooks is quite different between two fields. In our teaching, some teachers use easy textbooks for other statistics and some use difficult textbooks for mathematics. The relation between courses is very close, for example, the course of regression analysis has big impact on experiment design, and for each course, the textbooks are quite different, if we choose a easy textbook for regression analysis and a difficult textbook for experiment design, we will find it will be difficult for students to learn the course of experiment design.
3
How to Solve the Problems Described above
For the first problem, we should let the students know that the statistics is a tool, which can help you to solve some problems you interested in, if you want to use the tool very proficiently, you have to master some basic mathematical knowledge. So even if you don’t like learning mathematics, you must learn it. I hope when the students begin to learn mathematical course in the first year, teachers should tell them what the relationship between the basic mathematical knowledge (such as Mathematical Analysis and the higher algebra) and the major
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course which they will learn later. Then the students will have a learning target, which will give them courage to learn the difficult knowledge. What the teachers should do to solve this problem? In my opinion, the students are not really forget the knowledge, they just don’t have the conception of the relationship of the old knowledge and the new, if the teacher remind a little, many students will remember them. If necessary, we should repeat the old knowledge again, so that the students can accept the new knowledge quickly and well. Because of the specific characteristic of the statistics, we must treat it specific, How to solve the third question?Shiyong Feng used to conducts preliminary research on some teaching materials published recently, especially since 2000, draws some conclusions and forwards some suggestions with regard to compiling teaching materials of statistics of China. Some people think that the students in mathematical of science school should use the difficult textbooks, and others use the easy textbooks. I don’t think so, for some students in science school, they don’t suit to use the difficult textbooks, because their training objective is not to be research-based talents. Their training objective is to be professional talents. For example, our school is the second class undergraduate Unversity, many students major in statistics may go to work after graduation. Even if some students do graduate study, they will change major, such as economic statistics. But if we only emphasis on the applications, it can’t stand out our major’s characteristic, how to coordinate the contradiction? I think we should set courses and choose textbooks according to the practical situation of our school, which require the teachers for specialized courses to form a teaching team, they should establish a whole teaching system, draw up the teaching program and teaching target, let the textbook at suitable level, which not only reflect the subject character, but also pay attention to the application. Along with the improvement of the teaching level, the teachers can complie teaching materials by themselves, the textbook the write should be suitable for the students major in statistics. I think if we can do this, our major course teaching will have their characteristic of the self. The evaluation of the science students by society is they are able to think things, but they don’t know how to do. Our target is to break the view of the society, train out professional talents which are needed by the development of our society. We will try our best to make a contribution to nation's durable and stable development in statistics subject.
References 1. Zhou, H.: Reflections on establishing the system of statistical subjects. Statistical Research 2 (2005) 2. Li, Z.: The higher education in statistics and the trend of the subject constructing. Journal of Jiangxi University of Finance and Economics 5 (2003) 3. Feng, S.: Some Suggestions on Compiling Teaching Materials of Statistics for the Third Level Education. Statistical Research 6 (2004)
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4. Wei, X.: Discussion of the Development of the Statistical Study from a Framework of the Statistical Application. Statistical Research 8 (2005) 5. Lei, Q.: Where is the direction? Discussion for t the education of statistics at higher level. Statistical Research (3) (2001) 6. Zhou, Y.: The Analyze and Thought of Present Situation of Chinese Statistical Education. Journal of Xianning College 26(6) (December 2006) 7. Dai, T., Zhang, Y.: A comparative study of the Talent Training Models of Statistics Specialty in China. Journal of Hunan Institute of Engineering 20(3) (September 2010) 8. Li, L., Gu, L., Dong, Z.: The reforming and developing of the statistics subject. Journal of Hebei University 19(supp.) (August 1999) 9. Discussion of the Training of the Research Ability in the Undergraduate Period for the statistical subject students. Sun Yatsen University Forum 27(8) (2007) 10. Wei, Y.: The Reviews and Forcast for the Statistical Education of high level in China. Statistical Reasearch (1) (2001)
The Existence and Simulations of Periodic Solutions of a Leslie-Gower Predator-Prey Model with Impulsive Perturbations Kaihua Wang and Zhanji Gui* School of Mathematics and Statistics, Hainan Normal University, Haikou, Hainan, 571158, P.R. China [email protected]
Abstract. The principle aim of this paper is to explore the existence of periodic solution of a Leslie-Gower predator-prey model with impulsive perturbations. Sufficient and realistic conditions are obtained by using Mawhin’s continuation theorem of the coincidence degree. Further, some numerical simulations show that our model can occur in many forms of complexities including periodic oscillation and chaotic strange attractor. Keywords: Periodic Solution, Leslie-Gower System, Impulses, Coincidence degree theory.
1
Introduction
The Leslie-Gower formulation is based on the assumption that reduction in a predator population has a reciprocal relationship with per capita availability of its preferred food [1–3]. Generally, a traditional Leslie-Gower predator-prey model takes the form:
x = x(B (x ) − d ) − cxy y = y s − h y x where x, y stand for prey and predator density respectively, c is a positive constant,
d > 0 is the death rate constant, and B( x ) is a birth rate function. B( x ) satisfies the y p . The term h is called Leslie-Gower following basic assumption B ( x ) = m x q+x
term. Dynamic behaviors of Leslie-Gower predator-prey model have been studied widely [4–7], but the corresponding problems with periodic coefficients and impulsive perturbations have not been fully studied. In this paper, we will study the following impulsive Leslie-Gower system: *
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105
y1 (t ) = y1 (t )[B( y1 (t )) − d (t ) − c(t ) y1 (t )] − a(t ) y1 (t ) y2 (t ), t ≠ t k y (t ) y 2 (t ) = y2 (t ) s(t ) − h(t ) 2 , t ≠ t k y1 (t ) p (t ) B( y1 (t )) = , t ≠ tk q (t ) + y1m (t ) Δy (t ) = x t + − x t − = I i x t − , i = 1,2, t = t , k ∈ Z + i k i k k i k k i k
(1)
( ) ( )
( )
In system (1), we give two hypotheses as follows: (H1). a (t ) , c(t ) ,
d (t ) , p(t ) , q(t ) , s (t ) and h(t ) are all nonnegative ω -periodic functions defined on R . (H2).
1 + I ki > 0 and there exists a positive integer q such that t k + q = t k + ω ,
I ki + q = I ki (i = 1,2 ) . 2
Existence of Positive Periodic Solutions
To prove our results, we need the notion of the Mawhin’s continuation theorem formulated in [8]. Lemma 1. ([8]) Let X and Y be two Banach spaces. Consider an operator equation Lx = λNx where L : Dom L X → Y is a Fredholm operator of index zero and
λ ∈ [0,1]
is a parameter, then there exist two projectors
P : X → X and
Q : Y → Y such that Im P = Ker L and Im L = Ker Q . Assume that N : Ω → Y is L-compact on Ω , where Ω is open bounded in X . Furthermore, assume that (a) for each λ ∈ (0,1) , x ∈ ∂Ω ∩ Dom L , Lx
≠ λNx ;
(b) for each x ∈ ∂Ω ∩ Ker L , QNx
≠ 0; (c) for each deg { JQN , Ω ∩ Ker L , 0} ≠ 0 , where J : Im Q → Ker L is an isomorphism and deg{*} represents the Brouwer degree.
Then the equation Lx = Nx has at least one solution in Ω ∩ Dom L . For the sake of convenience, we shall make some preparation. Let I
(
) the
⊂ R . Denote
x(t ) : I → R which are continuous at 1 ω t ∈ I , t ≠ t k and are left continuous for t = t k ∈ I .Let u = u (t )dt ,
ln 1 + I k1 Φ k ( x(tk )) = , k = 1,2,, q 2 ln 1 + I k 1 ω Define two projectors P and Q as P : X → KerL , Px = x(t )dt and
ω
0
q 1 ω Q : Y → Y , Q( y, c1 , , c q ) = y (s )ds + c k ,0, ,0 0 ω k =1
It can be easily proved that L is a Fredholm operator of index zero, that P, Q are projectors, and that N is L-compact on Ω for any given open and bound subset Ω in X . Now we are in a position to search for an appropriate open bounded subset Ω for the application of Lemma 1 corresponding to operator equation
λ ∈ (0,1]
Lx = λNx Suppose
that
x(t ) = ( x1 (t ), x2 (t ))
T
]
is
a
(4)
periodic
certain λ ∈ (0,1 . By integrating (4) over the interval
s ω ≥ h ω exp{x2 (ξ 2 ) − x1 (η1 )} − ln 1 + I k2 k =1
)
Because of (H3) we have
x1 (η 1 ) ≥ ln
hω sω +
ln (1 + I ) q
k =1
Thus we get
2 k
+ x 2 (ξ 2 ) ≥ ln
h + H3 N
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x1 (t ) ≥ x1 (η 1 ) − ≥ ln
³
ω
0
x&1 (t )dt −
¦ ln (1 + I ) q
2 k
k =1
h + H 3 − 2Mω − N
¦ ( q
k =1
(12)
)
ln 1 + I k2 := H 4
From (9)-(12), it follows that
x1 (t ) ≤ F1 = max{H 1 , H 4 }, x 2 (t ) ≤ F2 = max{H 2 , H 3 } Obviously, F1 and F2 are independent of λ . Thus, there exists a constant F3
{
}
, x 2 } ≤ F3 . Let r > F1 + F2 + F3 , Ω = x ∈ X : x c < r , then it is clear that Ω satisfies condition (a) of the Lemma 1 and N is L-compact on T Ω . When x = ( x1 , x 2 ) ∈ ∂Ω KerL = ∂Ω R 2 , x is a constant vector in
such that max
{x
> 0,
1
R 2 with x = r. Thus QNx ≠ 0 .
J : Im Q → KerL, (d ,0, ,0 ) → d . A direct computation gives deg {JQN , Ω ker L,0} ≠ 0 . By now we have proved that Ω satisfies all the Let
requirements in Mawhin’s continuation theorem. Hence, system (3) has at least one ω-periodic solution. By of (2), we derive that (1) has at least one positive ω-periodic solution.
3
Some Simulations
In this section, we shall discuss an example to demonstrate our main results. In (1), we take (H5): p(t ) = 0.93 + 0.3 sin t , q (t ) = 0.27 + 0.062 cos t ,
d (t ) = 0.46 + 0.1sin t , c(t ) = 0.43 + 0.12 cos t , a(t ) = 0.53 + 0.1sin t , s(t ) = 0.76 + 0.1 cos t , I k1 = 0.3, I k2 = 0.2, h(t ) = 0.38 + 0.13 sin t , m = 2, t k = kT .
If T = 2 π , then obviously all conditions of Theorem 1 are satisfied. Thus system 3
(1) under the conditions (H5) has a unique 2π -periodic solution (See Fig.1-Fig.3, where
[x(t ), y(0)]T = [0.1,0.1]T ). The influence of the period pulses is obvious.
If T = 5 , then (H2) is not satisfied. Periodic oscillation of system (1) under the conditions (H5) will be destroyed by impulsive effect. Numeric results (see Fig.4) show that system (1) under the conditions (H5) has Gui chaotic strange attractors [9, 10].
The Existence and Simulations of Periodic Solutions
Fig. 1. Time-series of system(1)with T
= 2π 3
x(t )
evolved in
2π -periodic solution of system (1) with T = 2π 3
Fig. 3. Phase portrait of
y (t ) system(1) with T = 2π 3 Fig. 2. Time-series of
111
evolved in
Fig. 4. Phase portrait of chaotic strange attractor of system (1) with T = 5
Acknowledgments. This work is supported by the National Natural Science Foundation of China (60963025); Hainan Nature Science Foundation (110007, 609009) in China; Start-up fund of Hainan Normal University (00203020201); Foundation of the Office of Education of Hainan Province (Hj2009-36, Hnjg201111) and the Foundation of Hainan College of Software Technology (Hr200808, HrZD201101).
References 1. Liu, K.Y.: Dynamic behaviors of a Leslie-Gower predator-prey model with birth pulse. Journal of Biomathematics 23(3), 390–398 (2008) 2. Leslie, P.H.: A Stochastic model for studying the properties of certain biological systems by numerical methods. Biometika 45(1), 16–31 (1958) 3. Zhang, J., Wang, K.: On the persistence of a Leslie system in a polluted environment. Journal of Biomathematics 21(4), 501–508 (2006) 4. Liu, H.X.: Dynamic properties analysis of a modified Leslie-Gower type preypredator systems. Journal of Guangdong Ocean University 29(3), 53–58 (2009) 5. Li, Z.: Permanence and global attractivity of a predator-prey model with modified LeslieGower and Holling type II schemes with feedback controls. Mathematics in Practice and Theory 41(7), 126–130 (2011) 6. Zhang, L.M.: Stability and bifurcation in a discrete predator-prey system with LeslieGower type. Sichuan University of Arts and Science Journal 20(2), 13–15 (2010) 7. Aziz-Alaoui, M.A., Daher Okiye, M.: Boundedness and global stability for a predator-prey model with modified Leslie-Gower and Holling type II schemes. Applied Mathematics Letters 16, 1069–1075 (2003)
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8. Gaines, R.E., Mawhin, J.L.: Coincidence degree and nonlinear differential equations. Springer, Berlin (1977) 9. Zhang, J., Gui, Z.J.: Existence and stability of periodic solutions of high-order Hopfield neural networks with impulses and delays. Journal of Computational and Applied Mathematics 224, 602–613 (2009) 10. Zhang, J., Gui, Z.J.: Periodic solutions of nonautonomous cellular neural networks with impulses and delays. Nonlinear Analysis: Real World Applications 10, 1891–1903 (2009)
The Existence and Simulations of Periodic Solution of Leslie Predator-Prey Model with Impulsive Perturbations Kaihua Wang, Wenxiang Zhang, and Zhanji Gui School of Mathematics and Statistics, Hainan Normal University, Haikou, Hainan, 571158, P.R. China [email protected] Abstract. In this paper, we investigate the predator-prey system governed by impulsive differential equation with Leslie functional response. Sufficient conditions are obtained for the existence of periodic solutions. The main approach is based on Mawhin’s continuation theorem of the coincidence degree. Further, some numerical simulations demonstrate that our model can occur in many forms of complexities including periodic oscillation and chaotic strange attractor. Keywords: Periodic Solution, Impulses, Simulation, Coincidence degree theory.
1
Introduction
In recent years, the predator-prey system with Leslie functional response has been studied by many authors[1,2,3,4,5,6,7,8]. The Leslie functional response is based on the assumption that reduction in a predator population has a reciprocal relationship with per capita availability of its preferred food. Paper [1] considers a Leslie model with two predator species to compete against each other. Model is as follows: ⎧ x (t) = rx 1 − xk − m1 xy ⎪ ⎪ 1 − m2 xy2 , ⎨ l1 y1 +αy2 y1 (t) = y1 s1 − , x ⎪ ⎪ ⎩ y (t) = y2 s2 − l2 y2 +βy1 , 2 x where the biological significance of parameters can be seen in [1]. In this paper, we will study the corresponding predator-prey model with periodic coefficients and impulsive perturbations. We obtain the system: ⎧ ⎪ x (t) = r(t)x(t) 1 − x(t) − m1 (t)x(t)y1 (t) − m2 (t)x(t)y2 (t), ⎪ k(t) ⎪ ⎪ ⎪ ⎪ l1 (t)y1 (t)+α1 (t)y2 (t) ⎪ , ⎨ y1 (t) = y1 (t) s1 (t) − x(t) (1) l (t)y (t)+α (t)y (t) y2 (t) = y2 (t) s2 (t) − 2 2 x(t)2 1 , ⎪ ⎪ ⎪
⎪ ⎪ Δx(tk ) = x(t+ ) − x(t− ) = Ik x(t− ) ⎪ k k k ⎪ i = 1, 2, k ∈ Z + . ⎩ − − Δyi (tk ) = yi (t+ k ) − yi (tk ) = Iik yi (tk ) C. Liu, J. Chang, and A. Yang (Eds.): ICICA 2011, Part II, CCIS 244, pp. 113–120, 2011. c Springer-Verlag Berlin Heidelberg 2011
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In system (1), we give two hypotheses as follows: (H1). r(t), k(t), mi (t), si (t), li (t) and αi (t) are all nonnegative ω-periodic functions defined on R. (H2). 1 + Ik > 0, 1 + Iik > 0 and there exists a positive integer q such that tk+q = tk + ω, Ik+q = Ik , Ii(k+q) = Iik . (i = 1, 2, k ∈ Z + )
2
Existence of Positive Periodic Solutions
To prove our results, we need the notion of the Mawhin’s continuation theorem formulated in [9]. Lemma 1. ([9]) Let X and Y be two Banach spaces. Consider an operator equation Lx = λN x where L : DomL ∩ X → Y is a Fredholm operator of index zero and λ ∈ [0, 1] is a parameter, then there exist two projectors P : X → X and ¯ →Y Q : Y → Y such that ImP = KerL and ImL = KerQ. Assume that N : Ω ¯ is L-compact on Ω, where Ω is open bounded in X. Furthermore, assume that (a) for each λ ∈ (0, 1), x ∈ ∂Ω ∩ DomL, Lx = λN x; (b) for each x ∈ ∂Ω ∩ KerL, QN x = 0; (c) deg {JQN, Ω∩ KerL, 0} = 0, where J : ImQ → KerL is an isomorphism and deg{∗} represents the Brouwer degree. ¯ ∩ DomL. Then the equation Lx = N x has at least one solution in Ω For the sake of convenience, we shall make some preparation. Let I ⊂ R. Denote by P C(I, R3 ) the space of functions x(t) : I → R3 which are continuous at ω t ∈ I, t = tk and are left continuous for t = tk ∈ I. Let u ¯ = ω1 0 u(t)dt, u 1 ω u(t) v = ω 0 v(t) dt, where u(t), v(t) are ω-periodic functions. Theorem 1. Suppose (H1) and (H2) hold, furthermore, the following conditions are satisfied. (H3). M − m ¯ 1 exp{H1 } − m ¯ 2 exp{H2 } > 0; (H4). Ni exp{F } − α ¯ i exp{Hj } > 0, Ni exp{F } − l i exp{Hi } > 0. where q Ni exp{F } − l i exp{Hi } > 0, Ni = s¯i + ω1 ln(1 + Iik ), k=1
q q H = ln M + 2M ω + |ln(1 + Ik )|, Hi = Ai + 2Ni ω + | ln(1 + Iik )|, r k=1 k=1
(k) q ¯ 1 exp{H1 }−m ¯ 2 exp{H2 } F = ln M−m − 2M ω − | ln(1 + Ik )|, r (k) k=1 Nj exp{H} , ln , i, j = 1, 2, i = j. Ai = min ln Ni exp{H} α ¯j l i
Then system (1) has at least one positive ω- periodic solution.
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115
Proof. Let exp{x(t)} → x(t),
exp{yi (t)} → yi (t),
(2)
then the system (1) becomes ⎧ ⎪ x (t) = r(t) 1 − exp{x(t)} − m1 (t) exp{y1 (t)} − m2 (t) exp{y2 (t)}, ⎪ k(t) ⎪ ⎪ ⎪ l (t) exp{y (t)}+α 1 1 1 (t) exp{y2 (t)} ⎪ ⎨ y (t) = s (t) − , 1
exp{x(t)} ⎪ ⎪ Δx(tk ) = ln(1 + Ik ) ⎪ ⎪ i = 1, 2, k ∈ Z + . ⎩ Δyi (tk ) = ln(1 + Iik )
In order to use Lemma 1, we set x = (x(t), y1 (t), y2 (t))T , X = {x ∈ P C(R, R3 )| x(t + ω) = x(t)}, Y = X × R3q . Then it is standard to show that both X and Y are Banach space when they are endowed with the norm: ||x||c = sup |x(t)| t∈[0,ω]
and ||(x, c1 , . . . , cq )|| = (||x||2c + |c1 |2 + · · · + |cq |2 )1/2 . Set L : DomL ⊂ X → Y as (Lx)(t) = (x(t), ˙ (Δx(t1 ), . . . , Δx(tq ))), where 3 3 DomL = {x ∈ X|x (t) ∈ P C(R, R )},KerL = R and
At the same time, we denote N : X → Y as (N x)(t) = (f (t, x(t)), (Φ1 (x(t1 )), . . . , Φq (x(tq )))) where ⎛ ⎞ r(t) 1 − exp{x(t)} − m1 (t) exp{y1 (t)} − m2 (t) exp{y2 (t)} k(t) ⎜ ⎟ 1 (t) exp{y2 (t)} ⎟, f (t, x) = ⎜ s1 (t) − l1 (t) exp{y1 (t)}+α ⎝ ⎠ exp{x(t)} l2 (t) exp{y2 (t)}+α2 (t) exp{y1 (t)} s2 (t) − exp{x(t)} ⎛ ⎞ ln(1 + Ik ) Φk (x(tk )) = ⎝ ln(1 + I1k ) ⎠ , k = 1, 2, . . . , q. ln(1 + I2k ) Define two projectors P and Q as ω P : X → KerL, P x = ω1 0 x(t)dt; q ω 1 Q : Y → Y , Q(y, c1 , . . . , cq ) = ω 0 y(s)ds + ck , 0, . . . , 0 . k=1
It can be easily proved that L is a Fredholm operator of index zero, that P , ¯ for any given open and bound Q are projectors, and that N is L-compact on Ω subset Ω in X. Now we are in a position to search for an appropriate open bounded subset Ω for the application of Lemma 1 corresponding to operator equation Lx = λN x, λ ∈ (0, 1].
(4)
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Suppose that x(t) = (x(t), y1 (t), y2 (t))T is a periodic solution of (4) for certain λ ∈ (0, 1]. By integrating (4) over the interval [0, ω], we get ω r¯ω = 0 r(t) exp{x(t)} + m (t) exp{y (t)} + m (t) exp{y (t)} dt 1 1 2 2 k(t) q (5) − ln(1 + Ik ), k=1
s¯i ω =
ω
li (t) exp{yi (t)}+αi (t) exp{yj (t)} dt exp{x(t)} 0
−
i, j = 1, 2, i = j.
q
ln(1 + Iik ),
k=1
(6)
From (4), (5), (6), we can obtain ω ω r(t) exp{x(t)} |x (t)|dt ≤ + m (t) exp{y (t)} + m (t) exp{y (t)} dt 1 1 2 2 0 0 k(t) q +¯ rω + ln(1 + Ik ) (7) k=1 q = 2¯ rω + 2 ln(1 + Ik ) := 2M ω, k=1
Since x(t), yi (t) ∈ P C([0, ω], R), there exist ξ, η, ξi , ηi ∈ [0, ω], such that x(ξ) = inf x(t), x(η) = sup x(t), yi (ξi ) = inf yi (t), yi (ηi ) = sup yi (t). t∈[0,ω]
t∈[0,ω]
t∈[0,ω]
t∈[0,ω]
It follows from (5) that r¯ω ≥ which implies x(ξ) ≤ ln
r k M
( kr )
ω exp{x(ξ)} −
ln(1 + Ik ),
k=1
. Thus we get
x(t) ≤ x(ξ) + ≤ ln
q
M
( kr )
ω 0
|x (t)| dt +
+ 2M ω +
q
q
|ln(1 + Ik )|
k=1
|ln(1 + Ik )| := H.
k=1
It follows from (6) that li ω exp{yi (ξi )} + α ¯i ω exp{yj (ξj )} ≤ Ni ω exp{H}, which implies
Ni exp{H} Nj exp{H} yi (ξi ) ≤ min ln , ln := Ai . α ¯j li
(9)
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Thus we get yi (t) ≤ yi (ξi ) +
ω 0
|yi (t)|dt +
≤ Ai + 2Ni ω +
q
q
| ln(1 + Iik )|
k=1
(10)
| ln(1 + Iik )| := Hi .
k=1
It follows from (5) that r¯ω ≤
r k
q
ω exp{x(η)} + m ¯ 1 ω exp{H1 } + m ¯ 2 exp{H2 } −
ln(1 + Ik ).
k=1
Because of (H3) we have x(η) ≥ ln
¯ 2 exp{H2 } M −m ¯ 1 exp{H1 } − m r
.
k
Thus we get p ω x(t) ≥ x(η) − 0 |x (t)|dt − | ln(1 + Ik )| k=1
q ¯ 1 exp{H1 }−m ¯ 2 exp{H2 } ≥ ln M −m − 2M ω − | ln(1 + Ik )| := F. r (k) k=1
(11)
It follows from (6) that li ω exp{yi (ηi )} + α ¯ i ω exp{yj (ηj )} − ln(1 + Iik ). exp{x(ξ)} q
s¯i ω ≤
k=1
Because of (H4) we have ⎧ ⎫ ⎨ ln Ni exp{F }−α¯ i exp{Hj } , ⎬ li yi (ηi ) ≥ max := Bi . ⎩ ln Nj exp{F }−lj exp{Hj } ⎭ α ¯j Thus we get yi (t) ≥ yi (ηi ) −
ω 0
|yi (t)|dt −
≥ Bi − 2Niω −
q k=1
q k=1
|ln(1 + Iik )|
|ln(1 + Iik )| := Fi .
(12)
From (9)-(12), it follows that |x(t)| ≤ D = max{|H| , |F |}, |yi (t)| ≤ Di = max{|Hi | , |Fi |}, Obviously, D and Di are independent of λ. Thus, there exists a constant D3 > 0, such that max {|x|, |yi |} ≤ D3 . Let r > D + D1 + D2 + D3 , Ω = {x ∈ X : ||x||c < r}, then it is clear that Ω satisfies condition (a) of the Lemma 1 and N is
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¯ When x = (x, y1 , y2 )T ∈ ∂Ω ∩ KerL = ∂Ω ∩ R3 , x is a constant L-compact on Ω. vector in R3 with x = r. Thus QN x = 0. Let J : ImQ → KerL, (d, 0, . . . , 0) → d. A direct computation gives deg{JQN, Ω ∩ ker L, 0} = 0. By now we have proved that Ω satisfies all the requirements in Mawhin’s continuation theorem. Hence, system (3) has at least one ω-periodic solution. By of (2), we derive that (1) has at least one positive ω-periodic solution.
3
Some Simulations
In this section, we shall discuss an example to illustrate the main results. For system (1), we take (H5): tk = kT , r(t) = 1 + 0.5 cos t, k(t) = 1 + 0.5 cos t, m1 (t) = 2 + sin t, m2 (t) = 2 + sin t, s1 (t) = 1 + 0.2 sin t, l1 (t) = 3 + cos t, α1 (t) = 0.6 + 0.4 sin t, s2 (t) = 1 + 0.3 sin t, l2 (t) = 3 + 0.8 cos t, α2 (t) = 0.6 + 0.3 sin t, Ik = −0.2, I1k = −0.2, I2k = −0.2. Obviously, all conditions of Theorem 1 are satisfied. If T = π/2, then system (1) under the conditions (H4) has a unique 2πperiodic solution (In Fig.1-Fig.4, we take [x(t), y1 (0), y2 (0)]T = [0.1, 0.1, 0.1]T ). We find the occurrence of sudden changes in the figures of the time-series and phase portrait. The influence of pulse is obvious. If T = 2, then (H2) is not satisfied. Periodic oscillation of system (1) under the conditions (H5) will be destroyed by impulsive effect. Numeric results (see Fig.5-Fig.6) show that system (1) under the conditions (H5) has Gui chaotic strange attractor [10].
Fig. 1. Time-series of x(t) evolved in system (1) with T = π/2
Fig. 2. Time-series of y1 (t) evolved in system (1) with T = π/2
Periodic Solution of Impulsive Leslie Predator-Prey Model
119
Fig. 3. Time-series of y2 (t) evolved in system (1) with T = π/2
Fig. 4. Phase portrait of 2π-periodic solution of system (1) with T = π/2
Fig. 5. Phase portrait of chaotic strange attractor of system (1) with T = 2
Acknowledgments. This work is supported jointly by the Natural Sciences Foundation of China under Grant No. 60963025; Natural Sciences Foundation of Hainan Province under Grant No. 110007; Start-up fund of Hainan Normal University under Project No. 00203020201; Foundation of the Office of Education of Hainan Province (Hj2009-36, Hnjg2011-11) and the Foundation of Hainan College of Software Technology (Hr200808, HrZD201101).
References 1. Xie, W.X., Wang, W.D.: Qualitative analysis of a Leslie predator-prey system with competition. Journal of Southwest University (Natural Science Edition) 31(3), 18– 21 (2009) 2. Aziz-Alaoui, M.A.: Study of a Leslie-Gower type tritrophic population model. Chaos, Solitons Fractals 14, 1275–1293 (2002) 3. Liang, Z., Pan, H.: Qualitative analysis of a ratio-dependent Holling-Tanner model. J. Math. Anal. Appl. 334, 954–964 (2007) 4. Lu, Z.Q., Liu, X.: Analysis of a predator-prey model with modified Holling-Tanner functional response and time delay. Nonlinear Analysis. Real World Applications 9, 641–650 (2008)
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5. Chen, Y.M., Li, Q.H., Xu, D.G.: Study on dynamics of a modified Leslie predatorprey system. Guangxi Sciences 18(1), 7–10 (2011) 6. Liang, Z.Q., Chen, L.S.: Stability of periodic solution for a discrete Leslie predatorprey system. Acta Mathematica Scientia 26A (2006) 7. Pan, H.W., Liang, Z.Q.: Existence of positive periodic solution for a Leslie system with stage structure. Mathematics in Practice and Theory 40(16), 130–137 (2010) 8. Liu, X., Chen, L.S.: Global dynamics of the periodic logistic system with periodic impulsive perturbations. J. Math. Anal. Appl. 289, 279–291 (2010) 9. Gaines, R.E., Mawhin, J.L.: Coincidence degree and nonlinear differential equations. Springer, Berlin (1977) 10. Zhang, J., Gui, Z.J.: Periodic solutions of nonautonomous cellular neural networks with impulses and delays. Nonlinear Analysis: Real World Applications 10, 1891– 1903 (2009)
Solutions Research of Ill-Posed Problem and Its Implementation Yamian Peng, Taotao Yu, and Yali He Hebei United University, Tangshan, 063009, Hebei, P.R. China [email protected]
Abstract. Problems in mathematics among a class of problems by the way, the solution of the original data it is not the case for change is unstable. It is characterized, no matter how small changes in the original data, but also can cause large changes in any solution. The ill-posed problem of the wide range of applications, but also the development of science and technology play an important role. As ill-posed problems started relatively late, ill-posed problem in the country of very few people. But its role is very big, so the solution of illposed problem is necessary. This paper mainly reviewed the commonly used selection method and regularization algorithm which introduces the regularization algorithm, which is now the most widely used and the most extensive. Keywords: ill-posed problems, first kind of operator equation, regularization method.
existence of the quality of recession, the details of the specific performance of fuzzy or missing images, feature Edge is not clear so that the image quality degradation in the imaging process can be expressed as:
g ( x, y ) = h( x, y ) f ( x ', y ')dxdy + n( x, y ) Where, g ( x, y ) is the image quality deterioration;Q f ( x ', y ') to the original image or surface features; n ( x , y ) said random noise; h ( x, y ) for quality degradation function. It is a function associated with a variety of factors. But in the actual image processing, the application data can generally only the image quality degradation, in dealing with the above equation, we recorded data with random noise, that is, with perturbation. Our most important solution is the original image, if the problem is not fixed, the necessary stability can be obtained to find a way to ensure the image from the true. For some natural phenomena, when we used to study the application of mathematical methods, always first need to do some specific description of the problem, and its modeling. A long period of time that only appropriate people have practical significance given model can only be studied using mathematical methods, that this model exists and the solution is unique, and that the solution of the model input data Is stable. It is also proposed by Hadamard in 1923 posed the famous question the concept. It is also found that many natural phenomena described in the actual model due to certain conditions can not meet the above conditions, the socalled ill-posed problem. The difficulty is ill-posed problems, if the solution stability of the input data does not satisfy, then the observed data might cause a slight change in the great error of solution, so that the result will deviate from the reality. So for an ill-posed problem to obtain a stable solution is very important. Hadmard order to describe the mathematical and physical problems and with a reasonable boundary conditions posed the introduction of a posedness and illposedness of the concept. Let ρ X and ρU are F and U in the metric space, A: F → U is linear or nonlinear mapping. First, the given equation
Fx = y x ∈ X u ∈ U
(1)
We introduce the following definitions Definition1: Equation (1) is posed, and if it also satisfies the following three conditions:
C1 : ∀u ∈ U , z ∈ F exists to meet the equation (1) (Existence); C2 : Let u1,u2 ∈ U , if z1 and z2 are the equation (1) corresponds to the u1 ≠ u2 of the solution; the z1 ≠ z2 (uniqueness of solution); C3 : solutions in terms of relative to the space ( F ,U ) is stable even me (Stability
of Solutions), namely: ∀ε > 0, ∃δ ( ε ) > 0 , as long as
ρU ( u1 , u2 ) ≤ δ ( ε ) (u1 , u2 ∈ U )
(2)
Solutions Research of Ill-Posed Problem and Its Implementation
123
There
ρ F ( z1 , z2 ) ≤ ε ( Az1 = u1 , Az2 = u2 )
(3)
Where ρU ( u1 , u2 ) , ρ F ( z1 , z2 ) , (u1 , u2 ∈ U ) , ( z1 , z2 ∈ F ) that the distance between elements. Conversely, if the above three conditions, at least one is not met, called it ill-posed. Note: The definition of ill-posed problem is even given metric space ( F ,U ) , since the same question in different posedness of metric space may not be the same. Posed above three conditions are of profound practical background. For practical problems, we want to exist and the only solution. More importantly, the actual data obtained are similar to data obtained by observation, and accurate data there is some error, which is our approximation of the actual processing of data ( Ah , uδ ) , rather than accurate data ( A, u ) , because accurate data is often unknown . If the raw data of the small error will result in the approximate solution for a serious deviation from the true solution, the numerical results calculated will be meaningless.
2
The Ill-Posed Problem
Consider a heat conduction problem
ut ( x, t ) = u xx ( x, t ),( x, t ) ∈ (0, π ) × (0, T ) u (0, t ) = 0, u (π , t ) = 0, t ∈ (0, T ) u ( x,0) = f ( x), x ∈ (0, π )
(4)
By the initial temperature f ( x ) requested u ( x, t ) is posed. Separation of variables method can be used. ∞
f ( x ) = u ( x, 0) = Cn sin nx n =1
Cn = ∞
u ( x, t ) = ( n =1
2
2
π
π
0
π
π
0
f ( x ) sin nxds
f ( x) sin nxdx)e− n t sin nx 2
Right end of the series for any continuous function f ( x ) and t > 0 converge. However, if the temperature should be in t > 0 the initial measurement of the temperature distribution of the information seeking f ( x ) is ill-posed. The inverse problem: Set u ( x, T ) known, requested f ( x ) .Satisfy (4) in the equations and boundary conditions u ( x, t ) can be written as:
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∞
u ( x, t ) = Cn e − n T sin nx 2
(5)
n =1
Cn = e n T 2
2
π
π
0
u ( x, T ) sin nxdx
Particularly ∞
f ( x ) = u ( x, 0) = ( n =1
2
π
π
0
2
u ( x, T ) sin nxdx)e n T sin nx
(6)
If u ( x, T ) is u ( x, 0) = f ( x ) of the corresponding temperature field. Then the formula gives the expression of initial solution, and the only solution is easy to know. δ
，
But for any given u ( x, T ) measurements u ( x, T ) Even if the error δ small. The right end of the series may not converge, that solution does not depend continuously on the input data. Problem (2) According to equation (5) can be expressed as a general first integral equation b
( Kx)(t ) = k ( s, t ) x( s )ds = y (t ) a
By the y (t ) ∈ Y request x (t ) ∈ X problems ( X infinite-dimensional space) solving the integral equation
2
π
π
0
∞
, That
( sin nye − n T sin nx ) f ( y ) dy = u ( x, T ) 2
n =1
The exact solution from equation (6) gives. When the kernel function k ( x, t ) Relatively smooth, K is a linear compact operator, K −1 must be unbounded. So the problem must be ill-posed.
3
The Regularization Algorithm for Solving Ill-Posed Problems
Build on the regularization method, the long-standing guiding principle of constructing a suitable stabilization is functional, that is, functional stabilization methods. A more systematic exposition of early in the text is Groetsch spectrum theory-based work, but its methods and maneuverability is not strong, and its failure to achieve a higher regular asymptotic solutions of order. In recent years, Krisch made singular system theory is the mathematical concept of the polaron, which gives the establishment of regularization method provides a new theoretical basis. Construction of this section will give two regularization methods: variational principle based on the stabilization of functional methods and the theory based on singular value system is the annihilator method.
Solutions Research of Ill-Posed Problem and Its Implementation
125
When the selection method. Solutions for our requirements may be too compact case, however, many practical problems; it is not solvable class of compact sets, and with the equation
Fx = y
(7)
The approximate characteristics of the right end of the changes linked to, you can make it beyond the set FM . This problem is called ill-posed nature. −1
Let equation (7) in the operator F is such that the inverse operator F is not continuous within the set of FX, and possible solutions of the X set is not compact. Let elements of xT ∈ X and FxT = yT yT ∈ Y is linked to relationships.
Definition 2: If K ( y, δ ) has the following characteristics of operator time to call in the neighborhood of the equation Fx = y y = yT is regular. (1) the existence of such number of
δ1 > 0 ,
the operator K ( y, δ ) for all
ρY ( yT , yδ ) ≤ δ in any yδ ∈ Y sense;. (2) for all ε > 0 , the existence of δ 0 = δ 0 (ε , yT ) ≤ δ1 , so that inequalities ρY ( yδ , yT ) ≤ δ ≤ δ 0 can be drawn from the inequality ρ X ( xδ , xT ) ≤ ε A, where
δ , 0 ≤ δ ≤ δ1
and
xδ = K ( yδ , δ ) . Note: In this definition, the general said, does not assume that operator K of the single value. Used to represent the set yδ in any of K ( yδ , δ ) the elements. In many cases, the use of regular operator more convenient to other definitions, the above definition is included. Build on the regularization method, the long-standing guiding principle of constructing a suitable stabilization is functional, that is, functional stabilization methods. A more systematic exposition of early in the text is Groetsch spectrum theory-based work, but its methods and maneuverability is not strong, and its failure to achieve a higher regular asymptotic solutions of order. In recent years, Krisch made singular system theory is the mathematical concept of the polaron, which gives the establishment of regularization method provides a new theoretical basis. Construction of this section will give two regularization methods: the variational principle based on the stabilization of functional methods and the theory based on singular value system is the annihilator method.
4
The Ill-Posed Problem
Consider the integral equation is as follows: 1
K ( x) = x( s)ds = y (t ) , t ∈ [0,1] . 0
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Solving the equation y (t ) is the first order derivative, in the practical application of frequency of use as an example to test here. Take X = Y = L (0,1) , by solving 2
，
K * Kx = λ x , easy to get singular system {u j , x j , y j } j =1 Of which: ∞
2 ui = (2i − 1)π 2i − 1 πt xi = 2 cos 2 2i − 1 yi = 2 sin 2 π t
i∈N
When y (t ) = t , x( s ) = 1 .Presentation in front of ill-posed problems have already mentioned, the integral equation is ill-posed, if the traditional methods of numerical solution, the integration process into the results obtained solving equations with the true solution will be very different. Here we use the Tikhonov regularization method, the original singular system of equations
{u , x , y } j
j
j
substituted into the first N
entries formula, we have:
x
α ,δ
N
= j =0
Where,
α
u 2j
α + u 2j
( y δ , y j )x j
is the regularization parameter, δ
(8) is the disturbance error level
y = y + σδ , σ is a random number with values in [−1,1] . δ
Numerical calculations, on the t ∈ [0,1] discrete, taking ti =
i , i = 1,2, M m
by x j (t j ), y j (t j ), j ∈ 1,2, , N , the appropriate choice of regularization parameter T calculated Y is a regular solution. The test we choose δ = 0.01 , M to take 10, N to take 100. Because the randomness of σ test data will bring volatility to some extent, in order to eliminate this fluctuation, for the same α , δ values remain unchanged, Repeat 30 times calculated, and finally averaging the results of these experiments. This method is effective to overcome the σ random fluctuations caused by the experimental data to improve the repeatability of test results. Tests need to explain several issues: (1)Formula (8) in the N option. We take a different test N calculated to observe the spectral truncation of the regular solution of the situation. The results show that large values of N increase the amount of calculation is the solution of little effect; made too small, the program less computation, but with the true solution is the solution to increase the error by comparing the results, value About 100 more appropriate. (2)The selection of the regularization parameter. In order to describe the solution and the true solution is the approximation between the degree of error is defined as follows:
Solutions Research of Ill-Posed Problem and Its Implementation
Err ( x
α ,δ
)=
xα ,δ − x
2
n +1 α ,δ
Where, n is the number of discrete points. We define the Err ( x
α minimum α * , to find α * , the first find in the larger α =1e − 1, 2e − 2, ,1e − 7 , by Err ( xα ,δ ) as shown below:
Fig. 1. Graphical Solution of the different
127
α
) Wis the
context, taking
error comparison of regular
Then in the vicinity of α = 1e − 3 , take the α = 5e − 4,1e − 3,1.5e − 3,,5e − 3 calculated by comparing the error α = 1.5e − 3 is relatively small. Further broken
down in the vicinity of α is calculated and found little change in Err ( xα ,δ ) . α * = 1.5e − 3 is the best time to that organization parameters.
5
Summary
The numerical solution of ill-posed problems which looking for a fast and stable and practical numerical solutions. It is very important theoretical and practical significance. In this paper, the basic theory of ill-posed problems are discussed, based on the most optimal solution ideas, ill-posed problem for the stability of the algorithm and its implementation have been studied and the corresponding numerical examples. Acknowledgement. This paper is supported by the Natural Scientific Fund Project in Hebei Province (A2011209019).
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References 1. 2. 3. 4. 5. 6. 7.
Liu, J.: Ill-posed problems of regularization and application. Science Press, Beijing (2005) Xiao, T., Yu, S., Wang, Y.: Numerical solution of inverse problems. Science Press, Beijing (2003) Bo, H., Li, L.: Nonlinear ill-posed problem solving methods and applications. Science Press, Beijing (2011) Wang, Z.: Measurements is ill-posed problems are resolved method. Science Press, Beijing (2006) Ting, L., Cheng, J.: Numerical methods. Beijing University of Technology Press, Beijing (2005) Wu, M.: Equations of mathematical physics lecture. Higher Education Press, Beijing (2003) Liu, J.: A class of inverse problems and partial differential equations of the regularization method, Postdoctoral Research Report. Nanjing Normal University, Nanjing (2000)
In Vitro Evaluation on the Effect of Radiation Sterilizion on Blood Compatibility and Genotoxicity of a Femoral Prosthesis Guochong Chen, Qingfang Liu*, and Wen Liu School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou, Jiangsu, China 215123 [email protected], [email protected], [email protected]
Abstract. The aim of this study was to assess blood compatibility and genotoxicity of a femoral prosthesis sterilization by radiation, so as to evaluate the safety of radiation as a method of sterilization of these materials. We detected hemolysis rate to preliminarily assess the blood compatibility of the radiation sterilized femoral prosthesis. Genotoxicity were checked by a combined use of chromosome aberration test and Ames test; a series of performance tests of packaging material were also conducted to detecte whether radiation has any effect on physicochemical properties of packaging material. Haemolysis test show that the haemolysis rate of the test samples is 1.4% (<5%), which is coincidence with the criteria of the medical devices.After the irradiation and tests of packaging material, the sample materials and the package remained effective, the device remained sterile, and no adverse responses were detected in genotoxicity tests. Keywords: Femoral prosthesis, radiation sterilization, blood compatibility, genotoxicity.
1
Introduction
The femoral prosthesis has long been used in clinical settings to treat serious joint diseases. Materials of such products used clinically must not only be thoroughly sterilized before they can be used in medical procedures, but also be biologically compatible. It is reported that radiation sterilization with the proper dose is a good method for the sterilization of medical products [1,2]. An advantage of radiation sterilization is the fact that it sterilizes products evenly and thoroughly, and is a cold process .However, it is also reported that radiation induces several types of damage to DNA [3]. Does the radiation sterilized femoral prosthesis have any toxicity that restricting it’s application in clinic? The aim of our study was to assess biocompatibility of the femoral prosthesis after sterilization by exposuring to a set dose of gamma radiation from a cobalt-60 source. *
Ten samples from three product lots (30 total) were obtained, and the bioburden of each sample was estimated with a validated washing technique. The recovery rates were calculated for three random products. Based on the number of initial contaminating bacteria found in the samples, the verification dosage was determined by consulting Table 5 in the ISO11137-2 Standard [4]. The verification dosage at ±10% was used to radiate 100 samples, which were then evaluated for sterility. The verification experiment was considered successful only when less than 2 positive cases were found per 100 products, as assessed by the sterility tests.After radiation sterilization by the set dosage, the femoral prosthesis samples were sent to the lab for those testing. Cobalt source:The cobalt source of the research was provided by Technology Research Institute of Soochow University. Radiation intensity was 2.22X1015Bq. Absorbed dose measurement and regular dose monitoring were conducted according to the requirement of EN552. 1.2
Determination of Hemolysis Rate
The experimental process of hemolysis test was as follows: 1). Testing group: take 3 testing tubes, In each tube, add 2g test samples and 10ml 0.9% NaCl injectable solution. 2). Negative control group: take 3 testing tubes.In each tube, add 10ml 0.9%Nacl injectable solution.3). Positive control group, take 3 testing tubes.In each tube add 10ml distilled water. 4). Keep all above tubes in a constant temperature water bath at 37℃ for 30min.Then add 0.2ml diluted rabbit blood in each tube when they become homogeneous by agitation, keep them again in water bath at 37℃ for 60min. 5). Transfer the bathed blood solution to centrifugal tubes from testing tubes, and have them centrifuged at the speed of 2500rpm for 5min. 6). Use spectrophotometer to measure(545nm)the absorbance of centrifused solution ,by which the average value of each group is obtained. It is required that the absorbance of negative control should not be greater than 0.03, the absorbance of positive control should fall within 0.8±0.3. 7). Calculation of hemolysis rate:The hemolysis rate is calculated by equation (1): HR(%)=(A-B/C-B)×100.
(1)
In the equation, HR is hemolysis rate; A, B, C are absorbances of testing group, negative control group and positive control group respectively. 8). Criteria for result evaluation: The testing sample whose HR is less than 5% is considered as acceptable. 1.3
Chromosome Aberration Test
chromosome aberration test was conducted according to the methods described in literatures [5,6]. 1) Sample and control preparation: Four gram radiation sterilized sample was enclosed in a container and 20 ml sterilized 0.9% NaCl solution was added to the container. Then the container was placed in incubator at 37℃ for 72h to obtain the
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soaked solutoin.The test designs three dose groups (original soaked solution,1/3 soaked solution,1/9 soaked solution ). Negative control: saline. Positive control: a).Mitomycin (MMC) 0.25ug/ml (-S9MIX). b). Cyclophosphamide(Cp), 20ug/ml (+S9MIX). c). Metabolism. Activation: The metabolism activation test in vitro is done through the induction of S9 by polychlorinated biphenyl. 2) Experimental process:Peripheral blood from human subjects was drawn and cultured in 1640 culture (0.5 ml peripheral blood + 4.5 ml medium). After 24 hours of cultivation, the original soaked solution, 1/3 of the soaked solution, 1/9 of the soaked solution or an identical volume of saline was added to each culture flask (0.05 ml test solution/1ml medium). As a positive control, Cyclophosphamide (final concentration of 2.5 µg/ml medium) and S9 were added to a flask for six hours, after which time the cells were washed and the medium changed. After 24 hours of cultivation, the cells were harvested. Four hours before harvest, colchicine was added to the cultures. In the non-activation group, mitomycin was added (final concentration of 25 ng/ml medium), and cultivation was continued. Twenty-four hours after cultivation, the cells were harvested. Four hours before harvest, colchicine was added to the cultures. The harvested cells were placed on slides dyed with Giemsa stain. One hundred cells per group were analysed; the analysed cells were in mitotic metaphase and well dispersed, as seen by a microscope (100× magnification). The number of aberrant chromosomes were counted. 1.4
Ames Test
Salmonella typhimurium TA97, TA98, TA1535, TA100 and TA102 were designated as microbe models to evaluate gene mutagenesis according to the current ISO standard. Experimental procedure was as follows: An extract of an S9-mixture consisting of Salmonella typhimurium, which is histidine dependent, and radiation sterilized samples were added to 2 ml of top agar containing biotin and a tiny amount of histidine (about 0.05 mmol/L). The control consisted of 1/3 normal strength saline. The mixtures were mixed well and poured onto the substratum agar plate, which contained low nutrient concentration. The plate was inverted when the top agar coagulated and was incubated for 48 hours at a temperature of 37°C. Finally, the number of revertant colonies was counted. 1.5
Performance Test of Packaging Material
we selected the stain leakage test, vacuum leaking test,bacterial barrier properties test, accelerated ageing test and sealing adhesion test to evaluate the performance of the packaging material before and after radiation. 1). stain leakage test:This test consists of dropping Rhodamine B solution on the sealing area and observing whether the stain can leak through the seal. 2). Vacuum leaking test:Placing packaging material in a vacuum pump, observing whether water can leak out.
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3). Bacterial barrier properties test:Bacteria were prepared by inoculating Serratia marcescens in bouillon culture medium for 24 hours at 35°C. After sterilizing the packing material, we placed it on the microbench and aseptically acquired a sample. The sample was placed on the surface of a nutrient agar slide, and a 1 ml drop of Serratia marcescens solution (containing 5.6×107 cfu/ml of cells) was placed on the packing material with care to avoid leakage of the bacterial solution. The slide was covered and cultured for 24 hours at 35°C. We then observed the growth condition of the bacteria. 4). Accelerated ageing test: The packaging material was stored at 60℃ for 28 days, the accelerated ageing test of 28 days, equals to 24 monthes in a normal environment. 5). Sealing adhesion test: In this test, we made the packing material into standard– size specimen and determined the sealing adhesion strength by using an XLD-A electronic tensile strength machine. 1.6
Statistical Analysis
All analyses were performed by SPSS 11.0 software (SPSS Base 11.0 for Windows. SPSS Inc. Chicago, Illinois, USA, 2002). A difference was considered to be statistically significant when p ≤0.05.
2
Results
2.1
Radiation Sterilization Dose Setting
＝
Adjusted average initial bacterial count of the sample was 313.6×1.06 332.49cfu per device. The verification dose was 9.529kGy(ZSP=1:SAL=10-2). One hundred products were radiated with the verification dose, and the sterility tests were conducted. No bacterial growth was observed in these 100 products. The minimum sterilization dose was determined to be 23.1Gy, SAL=10-6. 2.2
Determination of Hemolysis Rate
The results of hemolysis test are shown in table 1. By these date, HR was calculated as 1.4%, which was coincidence with the criteria of the medical devices. Table 1. Results of hemolysis test(n=9)
Group Negative control group Positive control group Testing group
O.D. ( X ±S)
hemolysis (%)
0.014±0.004
-
0.811±0.014
-
0.025±0.003
1.4
rate
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2.3
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Chromosome Aberration Test
The results of chromosome aberration test are shown in Table2. The metaphase analysis of the bone marrow cells revealed two types of chromosomal aberrations consisting of breaks and exchanges. No statistically significant differences were found between the different dosage groups and the negative control group, which means that the samples would not cause chromosome aberration. Table 2. Chromosomal abnormality analysis of tested cells -S9 24 h
-S9 48 h
N
CA rate (%)
S
N.S
100
2
B
MMC
52
25
B.E
Primary fluid
100
Primary fluid 1/3 Primary fluid 1/9
+S9 48 h
N
CA rate (%)
100
2
<0.01
62
45
B.E
<0.01
0
>0.05
100
2
B
>0.05
100
0
>0.05
100
0
100
2
>0.05
100
1
P
S
N
CA rate (%)
100
2
54
33
100
0
>0.05
>0.05
100
0
>0.05
>0.05
100
0
>0.05
100
0
>0.05
P
Cp
B
B
S9
S
P
B.E.S
<0.01
Note:statistical analysis with N.S control group. N:cell number; CA rate:hromosomal abnormality rate; S: style; B: chromosome breakage; E: chromosomal exchange; D: quadriradial. p: p value. 2.4
Ames Test
The results of the Ames test are shown in Table 3. There was no significant difference in reverted bioburden per utensil of extract liquid observed in the radiation sterilized sample group, the 1:5 dilution group and the 1:25 dilution group when compared with the negative control group under both activated and non-activated conditions. No dose-dependent effect was observed in any group. 2.5
Influence of Radiation on Medical Equipment
Dropping Rhodamine B solution on the sealing area and no stain was observed leaking through the seal.After irradiation;the vacuum leak test of the packing material
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G. Chen, Q. Liu, and W. Liu Table 3. Ames test results for radiation sterilized samples
TA97 -S9 extract liquid
㧦5 dilution 1㧦25 dilution 1
Number of reversions
x ±s
reverted Bio-burden per utensil
Extract Concentration
TA98
TA100
TA102
+S9
-S9
+S9
-S9
+S9
-S9
132±26
142±28
16±2
15±4
109±20
160±17
135±9
177±30
14±3
19±2
161±11
147±17
161±10
191±22
14±3
17±1
124±22
133±10
TA1535 +S9
-S9
+S9
317±42
325±25
11±3
22±7
334±6
308±23
13±1
19±5
290±71
313±10
19±3
20±3
spontaneous 117±10
167±13
13±3
16±2
139±12
157±26
198±10
213±32
16±1
17±2
Solvent (negative) control
118±35
167±7
17±3
25±3
149±37
119±25
177±19
173±11
18±6
32±5
Positive control
9AA 811±27
2,7AF 103±7
NaN3 876±49
MMC 969±47
NaN3102±9
2-AF 922±30
2-AF 887±63
2-AF 999±40
2-AF 1060±72
2-AA109±8
-S9
+S9
Table 4. Results of Sealing adhesion test(pre-irradiation and post-irradiation) (Ibs)
Sample
Pre-irradiation(N)
Post-irradiation(N)
1
0.3597
0.3596
2
0.3260
0.3260
3
0.3709
0.3710
4
0.3597
0.3597
5
0.2988
0.2922
6
0.2585
0.2584
7
0.2473
0.2473
8
0.2922
0.2922
9
0.2585
0.2584
10
0.2810
0.2809
11
0.3484
0.3485
12 Average
0.3260
0.3259
0.3106
0.3100
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does not detect any leakage;bacterial barrier properties test after cultivation, no serratia marcescens were found on the packing material or in the bottom of the culture media, this result shows that Serratia marcescens bacteria cannot penetrate the packing material, indicating that the packing material can function as a bacterial barrier;the accelerated ageing test of 28 days, equal to 24 monthes in a normal environment, finds no bacteria;a test of the adhesion capability for the packing material’s seal was conducted before and after irradiation,the result is shown in Table 4,the average adhesion strength of the seal before irradiation was 0.3106 N whereas the average adhesion strength of the seal after irradiation was 0.3100N,the radiation has no distinct influence on the adhesion strength of the seal.
3
Discussion
The evaluation of biomedical materials for compatibility with blood is a science in its infancy [7].A less than 5% hemolysis rate indicated that biomaterials corresponded to experimental requirement of hemolysis. An equal to and higher than 5% hemolysis ratio indicated that biomaterials exhibited hemolytic reaction [8]. In our study, hemolysis rate was investigated to be 1.4%, which was coincidence with the criteria of the medical devices. The genotoxicity evaluation, using more than one test system, is often pointed out [9]. In our study we combined two tests to check for the genotoxicity of the radiation sterilized femoral prosthesis. The results of chromosome aberration test indicate that there is no significant difference between the different dosage groups and the negative control group(p>0.05), which means that the samples will not cause chromosome aberration.The Ames test is commonly used as an initial screening tool for genotoxic activity,particuarly for point mutation-inducing activity [10]. The five strains have been widely used for backward mutation detection [10-12]. We judge the results to be positive if the number of revertant colonies induced by the materials at different doses was at least 2 times greater than that of the spontaneous control and the number exhibits a dose-effect relationship. The number of revertant colonies at certain test points should be 2 times more than that of the control, which shows repeatability and significant statistical differences according to the standards. We judge the results to be negative if the number of dose-dependent revertant colonies did not increase in repeated experiments and showed no statistical significance in the proportionally increased number of revertant colonies at any dose level, no dose-dependent effect was observed. The Ames test results for radiation sterilized femoral prosthesis were negative, indicating that the radiation sterilized samples had no mutagenicity effects on Salmonella typhimurium under these test conditions.
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A series of performance tests of packing material show that the packing material retained its imperviousness and other beneficial properties without causing secondary pollution, therefore, we conclude that radiation has no obvious effect on the product’s physicochemical properties, this product sterilized by radiation can be applied in the clinic while being stored on the shelf.
4
Conclusion
The study show that the radiation sterilized femoral prosthesis samples have preliminary good blood compatibility; a combined use of chromosome aberration test and Ames test show that the radiation sterilized femoral prosthesis has no genotoxicity under our test conditions; radiation will not change product’s physicochemical properties. Radiation sterilization is a biologically safe method for sterilization of medical devices. Acknowledgments. We would like to thank the Construction Projects of Preponderant Discipline of Colleges in Jiangsu Province (Radiation Hematology of Blood Transformation Medicine) for financial support of this study.
References 1. Nam, K.W., Yoo, J.J., Koo, K.H., Yoon, K.S., Kim, H.: Optimal sterilization method for the zirconia/alumina composites used for total hip replacements. J. Biomed. Mater Res. B Appl. Biomater 90, 962–966 (2009) 2. Brinston, R., Miller, A., Deeley, C.: Developments in radiation sterilisation. J. Med. Device Technol. 19, 36–37 (2008) 3. Demirel, C., Kilçiksiz, S., Ay, O.I., Gürgül, S., Ay, M.E., Erdal, N.: Effect of N-acetylcysteine on Radiation-induced Genotoxicityand cytotoxicity in Rat Bone Marrow. J. Radiat. Res. 50, 43–50 (2009) 4. ISO11137-2:Sterilization of health care products, Part 2: Establishing the sterilization dose, 5–14 (2006) 5. ISO10993-3. Biological evaluation of medical devices-part3: Tests for Genotoxicity, 3–4 (2003) 6. Yılmaz, S., Unal, F., Yüzbaşıoğlu, D.: The in vitro genotoxicity of benzoic acid in human peripheral blood lymphocytes. Cytotechnology 60, 55–61 (2009) 7. Mason, R.: Some methods for in vitro estimation of the blood compatibility of biomaterials. Bull. N Y Acad. Med. 48, 407–424 (1972) 8. Zhao, Z.M., Peng, C.H., Han, B.S., Gao, C.: In vitro blood compatibility of polyacrylamide grafted polypropylene membrane. J. Clin. Rehabil. Tissue Eng. Res. 8, 1517–1520 (2010) 9. de Rainho, C.R., Kaezer, A., Aiub, C.A., Felzenszwalb, I.: Ability of allium cepa L. root tips and tradescantia pallida var. purpurea in N-nitrosodiethylamine genotoxicity and mutagenicity evaluation. An Acad. Bras. Cienc. 82, 925–932 (2010)
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10. Hong, C.E., Lyu, S.: Genotoxicity detection of five medicinal plants in Nigeria. J. Toxicol. Sci. 36, 87–93 (2011) 11. Asakura, K., Satoh, H., Chiba, M., Okamoto, M., Serizawa, K., Nakano, M., Omae, K.: Genotoxicity studies of heavy metals: lead, bismuth, indium, silver and antimony. J. Occup. Health 51, 498–512 (2009) 12. Gahyva, S.M., Siqueira Jr, J.F.: Direct genotoxicity and mutagenicity of endodontic substances and materials as evaluated by two prokaryotic test systems. J. Appl. Oral Sci. 13, 387–392 (2005)
Evaluation of the Effects of Sterilization by Irradiation on Biocompatibility and Adaption of a Coronary Artery Stent Wen Liu, Qingfang Liu*, and Guochong Chen School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou, Jiangsu, China 215123 [email protected], [email protected], [email protected]
Abstract. Aim of this study was to evaluate the biocompatibility properties of a coronary artery stent following radiation sterilization (19.3 KGy). sensitisation, genotoxicity and properties of the packaging materials were tested. The results show that after the irradiation and accelerated ageing test, the sample products and the package remained effective. The device remained sterile, and no adverse responses were detected in sensitisation and genotoxicity tests. Radiation, as a sterilization method for these kind of materials, is worth generalising and applying more widely. Keywords: Genetoxicity, Sensitization, Radiation sterilization, Coronary artery stent.
1
Introduction
Coronary artery stent has long been used in clinical settings to treat artery diseases. The safety and effectiveness of these materials have been investigated by manufacturers, hospitals and medical organisations. Many factors, such as the design, quality and clinical application contribute to the safety of the coronary artery stent system[1]. Good biocompatibility would be needed for a ideal coronary stent. Such biocompatibility, including tissue and gene compatibility which refer to the compatibility of the system with human organs, tissue, cell organelles and biomacromolecules, had been proved good in our previous experiments [2]. However, considering such problems which are if the coronary stent still be biocompatible after radiation sterilization and if it becomes noxious and harmful to human body after radiation , system evaluation would be needed. 1.1
Materials and Methods
Radiation sterilization dose setting were conducted according to literatures[3,4]. Cobalt source:The cobalt source of the research was provided by Technology *
Research Institute of Soochow University. Radiation intensity was 2.22×1015Bq. Absorbed dose measurement and regular dose monitoring were conducted according to the requirement of EN552. After radiation sterilized, the disposable burette transfusion apparatus samples were sent to the tests, and after a series of the tests, properties of the packaging materials were tested [5]. 1.2
Sensitisation
A guinea pig maximisation test of the material identified below was conducted to evaluate the potential to cause delayed dermal contact sensitisation [6].The method of Magnusson and Kligman, as reported in Allergic Contact Dermatitis in the Guinea Pig, 1970, was employed with adaptations for a test article extract. The susceptibility of the Hartley guinea pig strain to a known sensitising agent, 1-chloro-2, 4dinitrobenzene (DNCB), has been substantiated at the Testing Centre of Sanitation & Environment Technical Institute, Soochow University (SDWH) with this method. The experimental procedure was as follows: (1). Sample preparation: For each phase of this test, a ratio of 0.2 g: 1 ml (test article to volume of vehicle) was used for the test extract . The test article was extracted in 0.9% sodium chloride (SC) at 70±2ºC for 24±2 hours. (2) Reagents: 0.9%SC, Freund’s complete adjuvant (FCA), 10% sodium dodecyl sulphate (10% SDS). (3) Each extract was intrademally injected and occusively patched to ten guinea pigs (per extract) in an attempt to induce sensitization. The vehicle was similarly injected and occusively patched to five control guinea pig (per vehicle). Following a recovery period, the test and control animals received a challenge patch of the appropriate test article extract and the reagent control. All sites were scored at approximately 24h and 48h after patch removal. (4) Evaluation of results:Magnusson and Kligman grades of 1 or greater in the test group generally indicate sensitisation, provided grades of less than 1 are seen in control animals. If grades of 1 or greater are noted in control animals, then the reactions of the test animals that exceed the most severe reaction in the control animals are presumed to be due to sensitisation. If the response is equivocal, re-challenge is recommended to confirm the results from the first challenge. The outcome of the test is presented as the frequency of positive challenge results in the test and control animals. 1.3
Intracutaneous Irritation Tests
The test article was evaluated for skin irritation in accordance with the guidelines of the ISO 10993-10:2002/Amd. 1:2006 tests for irritation and delayed-type hypersensitivity [6].This study was to determine potential skin irritation after the patches moistened by the extract were applied to the animals’ back. Experimental Procedure was as follows: The test article was extracted in 0.9% sodium chloride USP (SC). Each extract was intrademally injected and occusively patched to ten guinea pigs (per extract) in an attempt to induce sensitization. The vehicle was similarly injected and occusively
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patched to five control guinea pig (per vehicle). Following a recovery period, the test and control animals received a challenge patch of the appropriate test article extract and the reagent control. All sites were scored at approximately 24h and 48h after patch removal. 1.4
Micronucleus Tests
Micronucleus tests were conducted according to ISO10993-3 [11]. (1) 4 gram sample sterilized by irradiation was enclosed in a container and twenty milliliter sterilized 0.9% NaCl solution was added to the container. Then the container was placed in incubator at 37℃ for 72h to obtain the original soaked solutoin. The test designs three dose groups (original soaked solution,1/3 soaked solution,1/9 soaked solution ). Negative control: saline positive control: cyclophosphamide 2.5mg/ml (2) Experimental process: First, 50 mice were divided into 5 groups; each group included 5 females and 5 males (original soaked solution of tested sample, 1/3 soaked solution, 1/9 soaked solution, negative control and positive control). All mice were perfused orally with a dose of 0.2 ml/10 g of one of the following: original soaked solution, 1/3 soaked solution, 1/9 soaked solution, 0.9 NaCl (negative control) or 100 mg/kg cyclophosphamide (positive control). After 48 hours, all mice were killed by wringing the myelencephalon, and the femurs were removed immediately. The bone marrow of the medullary cavities was washed with foetal bovine serum and placed onto slides; the wash solution was mixed, and slides were prepared. The slides were dried, fixed, and dyed with Giemsa stain.
﹪
Finally, we observed 1000 polychromatic erythrocytes (PCE) of every mouse under a microscope with an oil objective to count the number of micronuclei exactly. We then calculated the average of every group (%) and the ratio of PCE to NCE. 1.5
Chromosomal Aberration Assay
Chromosomal aberration assay was conducted according to ISO10993-3 [11] and literature[8]. (1). Sample and control preparation: 4 gram sample sterilized by irradiation was enclosed in a container and 20 milliliter sterilized water was added to the container. Then the container was placed in incubator at 37℃ for 72h to obtain the soaked solutoin. The test designs three dose groups (original soaked solution,1/3 soaked solution,1/9 soaked solution). negative control: saline.positive control: Mitomycin (MMC) 0.25ug/ml (-S9MIX). Cyclophosphamide(Cp) 20ug/ml (+S9MIX). metabolism activation:The metabolism activation test in vitro is done through the induction of S9 by polychlorinated biphenyl.
②
①
③
Evaluation of the Effects of Sterilization
141
(2). Experimental process:Peripheral blood from human subjects was drawn and cultured in 1640 culture (0.5 ml peripheral blood + 4.5 ml medium). After 24 hours of cultivation, the original soaked solution, 1/3 of the soaked solution, 1/9 of the soaked solution or an identical volume of saline was added to each culture flask (0.05 ml test solution/1 ml medium). As a positive control, cyclophosphamide (final concentration of 2.5 µg/ml medium) and S9 were added to a flask for six hours, after which time the cells were washed and the medium changed. After 24 hours of cultivation, the cells were harvested. Four hours before harvest, colchicine was added to the cultures. In the non-activation group, mitomycin was added (final concentration of 25 ng/ml medium), and cultivation was continued. Twenty-four hours after cultivation, the cells were harvested. Four hours before harvest, colchicine was added to the cultures. The harvested cells were placed on slides dyed with Giemsa stain. One hundred cells per group were analysed; the analysed cells were in mitotic metaphase and well dispersed, as seen by a microscope (100×magnification). The number of aberrant chromosomes was counted. 1.6
Performance Test of Packaging Material
By consulting standards in ISO 11607-1 [12], we selected the stain leakage test, the accelerated ageing test, and the sealing adhesion test to evaluate the performance of the packaging material before and after radiation. (1) Stain leakage test: This test consists of dropping Rhodamine B solution on the sealing area and observing whether the stain can leak through the seal. (2) Sterile products were kept at 60°C for a given period (ISO-11607-2006 mentions that seven days at 60°C may be considered equivalent to 180 days of ageing at normal ambient conditions). Six products were chosen for sterility tests, among which six pieces were inoculated in anaerobic culture medium for five days at 30-35°C. Another six pieces were inoculated in fungal culture medium for seven days at 20-25°C. After incubation, the pieces were tested for bacterial or fungal growth. (3)Sealing adhesion test: In this test, we made the packing material into standard–size specimen and determined the sealing adhesion strength by using an XLD-A electronic tensile strength machine. (4) Tensile strength test of the product: In this test, we made the packing material into standard –size specimen and determined its tensile strength by using an XLD-A electronic tensile strength machine. (5) Vacuum leaking test of packing material: A vacuum leak test was conducted on 10 samples. It was concluded that the packaging has no leaks. (6) Bacterial barrier properties test: Bacteria were prepared by inoculating serratia marcescens in bouillon culture medium for 24 h at 35°C. After sterilizing the packing material, we placed it on the microbench and aseptically acquired a sample. The sample was placed on the surface of a nutrient agar slide, and a 1 ml drop of serratia marcescens solution (containing 5.6×107 cfu/ml of cells) was placed on the packing material with care to avoid leakage of the bacterial solution. The slide was covered and cultured for 24 h at 35°C. We then observed the growth condition of the bacteria.
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2
Results and Discussion
2.1
Bioburden and Recovery Rate
＝
The average Adjusted average initial bacterial count of the sample was 26,5×1.06 28.09 cfu per device.The verification dose was 6.5kGy(ZSP=1:SAL=10-2). One hundred products were radiated with the verification dose, and the sterility tests were conducted. No bacterial growth was observed in these 100 products. The the minimum sterilization dose was determined to be 19.3kGy, SAL=10-6 2.2
Sensitisation and Intracutaneous Irritation Tests
No evidence of sensitisation was observed. Clinical observations: All animals appeared clinically normal throughout the study. Under the conditions of this study, the SC test article extracts sterilized by radiation showed no evidence of causing delayed dermal contact sensitisation in the guinea pig. Results of intracutaneous irritation tests appear in Table 2. The response of skin on the testing side does not exceed that on the control side. Thus, it is identified as grade 0, indicating that the applied sample does not induce irritation to skin. Thus, the radiation sterilized samples do not induce irritation to skin under the conditions of this study. Sensitisation and, intracutaneous irritation tests showed that radiation sterilization does not affect the tissue compatibility of the coronary artery stent, indicating that the materials of the samples have no sensitization, no intracutaneous irritation. 2.3
Micronucleus Tests
The in vitro micronucleus test started to be used in genotoxicity in the 1970s.The ames test is the most widely used test among short-term carcinogenicity tests,while the micronucleus test can detects chromosomal damage in a further stage.The mutagenicity and genotoxicity evaluation, using more than one test system, is often pointed out. The micronucleus test is a reliable method for evaluating the effect of genetic toxicity on chromosomes. The micronucleus tests imply that in the three different dosage groups of the leached solution of the coronary artery stent system, there was no increase in micronucleus incidence rate or in the rates of polychromatic erythrocytes and normoblasts. There was no statistical difference in the micronucleus incidence rates of the test group and the negative control group, indicating that the experimental conditions did not increase the incidence rates of micronuclei or polychromatic erythrocytes in bone marrow (Table1). micronucleus test indicates that radiation sterilized samples have no mutagenicity under the conditions of this study. This means that the radiation sterilized coronary stent system did not cause the micronucleus rate to increase under our test conditions.
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Table 1. Micronucleus test results of polychromatic erythrocytes in mouse bone marrow Group
No.
Number of polychromatic RBC
PCE/NCE
Number of micronuclei
Micronucleus rate (%)
Lixiviated stock solution
10
10000
1.01
26
2.6
1/3 lixiviated stock solution
10
10000
1.04
28
2.8
1/9 lixiviated stock solution
10
10000
1.00
28
2.8
Cyclophosphamide
10
10000
1.04
304
30.4**
Normal saline
10
10000
1.01
27
2.7
**:Compared to the control group, P<0.01. 2.4
Chromosomal Aberration Assay
The genotoxicity test results are shown in Table 2. The tests of gene mutation and chromosome aberration which directly reflect mutagenicity of toxic chemicals are reliable methods to evaluate mutagenicity of toxic chemicals. The genotoxicity test results indicate that there was no distinct difference between the coronary artery stent system in the different dosage groups and the negative control group, which means that the product texture was not genotoxic (would not cause chromosomal aberrations). There was no significant difference between the test and control groups (p>0.05). Thus, this showed that the radiation sterilized materials had no genetic toxicity and did not cause chromosomal aberration. Table 2. Chromosomal abnormality analysis of tested cells -S9 24 h
-S9 48 h
N
CAratb (%)
S
N.S.
100
0
B
MMC
100
32
Bd. E
a
c
p
<0.01
+S9 48 h
n
CA rate (%)
100
0
100
43
n
Carate (%)
100
0
100
37
>0.05
100
2
>0.05
>0.05
100
1
>0.05
s
p
B.E
<0.01
Cp Primary fluid
100
1
>0.05
100
2
Primary fluid 1/3
100
1
>0.05
100
0
Primary fluid 1/9
100
0
>0.05
100
1
B
B B
>0.05
S9
s
pg
B. Ef.De
<0.01
100
0
>0.05
100
0
>0.05
Note: statistical analysis with N.S. control group. a=cell number; b=chromosomal abnormality rate; c= style; d=chromosome breakage; e= exchange; f= chromosomal g= p value. 2.5
Influence of Radiation on Medical Equipment
Before we use radiation to sterilize medical equipment, it is very important to consider the influence of the radiation on the stability of the equipment and its texture. Both the equipment’s texture and its design contribute to its radiation stability. In our study, A test
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of the adhesion capability for the packing material’s seal was conducted before and after irradiation. The results are shown in Table 3. Table 3. Adhesion strength of the seal(pre-irradiation and post-irradiation) Sample 1
Preirradiation (N) 0.0899
Postirradiation (N) 0.0898
2
0.1124
0.1124
3
0.1236
0.1238
4
0.1012
0.1012
5
0.1461
0.1460
6
0.1124
0.1123
7
0.0787
0.0787
8
0.0674
0.0673
9
0.0787
0.0786
10
0.0562
0.0562
The average adhesion strength of the seal before irradiation was 0.09666±0.02763 N whereas the average adhesion strength of the seal after irradiation was 0.09663±0.02765 N. SPSS 15.0 was used for the statistical analysis. the radiation has no distinct influence on the adhesion strength of the seal.Tensile strength test of the product: before and after irradiation, a tensile strength test was conducted on the product. The results are shown in Table 4.
Table 4. Tensile device strength (pre-irradiation and post-irradiation) Sample
Preirradiation (N)
Postirradiation (N)
1
0.1789
0.1789
2
0.2248
0.2248
3
0.2473
0.2472
4
0.2023
0.2023
5
0.2922
0.2922
6
0.2248
0.2248
7
0.1574
0.1574
8
0.1349
0.1348
9
0.1574
0.1574
10
0.1124
0.1123
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By statistical analysis, the average tensile strength before irradiation was 0.19324±0.05528 N whereas the average tensile strength after radiation was 0.19321±0.05530 N. The difference between pre- and post-radiation tensile strength values is not a normal distribution. The rank sum test of paired data gives S=3 and p=0.25>0.05; the tensile strength and seal adhesion strength test results showed no distinct difference between pre- and post-radiation samples. Similarly, the sample texture’s colour and clarity are unchanged. Therefore, we conclude that radiation has no obvious effect on the product’s physicochemical properties. After irradiation, the vacuum leak test of the packing material does not detect any leakage; Bacterial barrier properties test after cultivation, no serratia marcescens were found on the packing material or in the bottom of the culture media. This result shows that Serratia marcescens bacteria cannot penetrate the packing material, indicating that the packing material can function as a bacterial barrier. the accelerated ageing test of 42 days, equal to 1080 days in a normal environment, finds no bacteria. In summary, the tests indicate that the packing material retained its imperviousness and other beneficial properties without causing secondary pollution. this product sterilized by radiation can be applied in the clinic while being stored on the shelf.
3
Conclusion
No toxic or sensitising substances or particles were released from these stents after radiation sterilization. After simulated storage and radiation sterilization with the setting dose, both of physicochemical properties and packaging capability of sample products were not significantly changed, indicating that the product material is relatively stable for radiation. Therefore, radiation sterilization is a useful method to sterilize this material. Acknowledgments. We would like to thank the Construction Projects of Preponderant Discipline of Colleges in Jiangsu Province (Radiation Hematology of Blood Transformation Medicine) for financial support of this study.
References 1. Wu, L.R.: Follow the guidelines, Appropriate intervention for the treatment of coronary heart disease med and Philosophy. Clinical Decision Making Forum Edition 30(7), 14–21 (2009) 2. Fang, J.Y., Liu, Q.: Systematic evaluation on biocompatibility of Coronary Stents. Laboratory Animal and Comparative Med. 27, 19–122 (2007) 3. Zhang, T.C., Zhong, H.L., Liu, Q.: Research on dose setting for radiation sterilization of medical device. Radiat. Res. Radiat. Process 20, 103–107 (2002) 4. ISO11137-2 .Sterilization of health care products, Part 2: Establishing the sterilization dose, 5–16 (2006) 5. Hao, H.P.: Companion of biological evaluation criterion of medical devices. Standards Press, Beijing (2000)
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6. ISO 10993-10: Biological evaluation of medical devices-part10: Tests for irritation and sensitization. 2002/Amd.1, 05–15 (2006) 7. ISO10993-5: Biological evaluation of medical devices-part5:Tests for in vitrocytotoxicity,1–30 (2009) 8. Demirel, C., Kilçiksiz, S., Ay, O.I., Gürgül, S., Ay, M.E., Erdal, N.: Effect of N-acetylcysteine on Radiation-induced Genotoxicityand Cytotoxicity in Rat Bone Marrow. J. Radiat. Res. 50, 43–50 (2009) 9. Hong, C.E., Lyu, S.: Genotoxicity detection of five medicinal plants in Nigeria. J. Toxicol. Sci. 36, 87–93 (2011) 10. Gahyva, S.M., Siqueira Jr., J.: Direct genotoxicity and mutagenicity of endodontic substances and materials as evaluated by two prokaryotic test systems. J. Appl. Oral Sci. 13, 387–392 (2005) 11. ISO10993-3. Biological evaluation of medical devices-part3: Tests for genotoxicity, carcinogenicity and reproductive toxicity, 1–15 (2003) 12. ISO11607-1.Packaging for terminally sterilized medical devices—Part 1: Requirements for materials, sterile barrier systems, and packaging systems, 1–12 (2006) 13. Bunnak, J., Takigami, M., Ito, H., Shinozawa, T.: Gamma irradiation effects on cultured cells: investigated by the MTT method. J. Radiat. Res. 35, 205–212 (1994) 14. Holst, C.M., Oredsson, S.: Comparison of three cytotoxicity tests in the evaluation of the cytotoxicity of a spermine analogue on human breast cancer cell lines. Toxicol in Vitro 19, 379–387 (2005)
Evaluation of the Effects of Sterilization by Irradiation on Histocompatibility and Adaption of a Central Vein Catheter Wen Liu, Qingfang Liu*, and Guochong Chen School of Radiation Medicine and Public Health, Medical College of Soochow University, Suzhou, Jiangsu, China 215123 [email protected], [email protected], [email protected]
Abstract. The aim of this study was to evaluate the the biocompatibility properties of central vein catheter following radiation sterilisation (8.8kGy).we conducted a series of tests including cytotoxicity, sensitisation, intracutaneous irritation test, local reaction test after implantation and tests of properties of the packaging materials. The results show that after the irradiation and accelerated ageing tests, the sample products and the package remained effective. No toxic or sensitising substances or particles were released from the central vein catheter after radiation sterilisation. After simulated storage and radiation sterilisation with the setting dose, neither physicochemical properties nor packaging capability of sample products were significantly changed, indicating that the product material is relatively stable for radiation. Therefore, radiation sterilisation is a useful method to these kind of materials, and is worth generalising and applying more widely. Keywords: Cytotoxicity, Sensitization, radiation sterilization, central vein catheter.
1
Introduction
Central vein catheter (CVC) is a catheter placed into large vein in the neck, chest, or groin. It is widely used in clinic, such as administering medication or fluids, directly obtaining cardiovascular measurements such as the central venous pressure, being a tube of hemodialysis and so on. materials of such products used clinically must not only be thoroughly sterilised before they can be used in medical procedures, but also be biologically compatible. It is reported that radiation sterilisation with the proper dose is a good method for the sterilisation of medical products[1,2]. An advantage of radiation sterilisation is the fact that it sterilises products evenly and thoroughly, and is a cold process . However, system evaluation would be needed considering such problems which are if the CVC still be biocompatible after radiation sterilisation and if it becomes noxious and harmful to human body[3] after radiation. Cytotoxicity, *
sensitisation , Local reaction test after implantation and properties of the packaging materials were tested of central vein catheter after radiation sterilisation had been conducted. Thus, the objective of this study was to evaluate the safety of this CVC material following radiation sterilisation. 1.1
Sterilisation Dose Setting
The sample is named the central vein catheter.r The serial numbers for the six tested samples were CV-2008-1023,CV2008-1024,CV-2008-1025andCV-2008-1026. All samples were stored at room temperature.Ten samples from three product lots (30 total) were obtained, and the bioburden of each sample was estimated with a validated washing technique, according to literature. The recovery rates were calculated for three random products. Based on the number of initial contaminating bacteria found in the samples, the verification dosage was determined by consulting Table 5 in the ISO11137-2 Standard [4]. The verification dosage at ±10% was used to radiate 100 samples, which were then evaluated for sterility. The verification experiment was considered successful only when less than 2 positive cases were found per 100 products, as assessed by the sterility tests.After sterilisation, cytotoxicity, and properties of the packaging materials were tested of central vein catheter [5]. 1.2
Cytotoxicity Tests
Cytotoxicity tests were conducted in accordance with ISO10993-5 [6]and literature [7].Experimental procedure was as follows: 1) Cell strain: American Type Culture Collection CCLI (NCTC clone 929) cells were used. 2) Preparation of sample extracts: The sterilised sample was put into a culture flask, and MEM medium (10% FCS) was added (0.2 g/1 mL). The flask was sealed, and the sample was extracted at 37°C for 24 h. 3) Control preparation: a) Negative control: High-density polyethylene +MEM medium with 10% FCS (37°C, 24 h) b) Positive control: MEM medium with 10% feltal calf serum (10% FCS) and 0.5 % phenol (37°C, 24 h) c) Blank control: MEM medium with 10% FCS (37°C, 24 h). 4) Cell culture: L929 cells were cultured in MEM medium supplemented with 10% FCS at 37°C in a humidified atmosphere of 5% CO2. L929 cells were digested with 0.5% trypsin (EDTA). Suspended cells (1×105 cells/ml) were cultured in 96-well plates with 100 µl per well. After the cells had formed a monolayer, the original culture medium was discarded, and 100 µl of the sample extract, positive control solution or negative control solution was added. 5) Cell morphological observation and evaluation of cytotoxicity: After 24 h of incubation, cellular morphology was observed in the 96-well plate, and 50 µl MTT (1 mg/mL) was added to each well. The cells were further cultured for two hours, after
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which the media was removed, and 100 µl isopropanol was added to dissolve the precipitate. The absorption of Sample group was measured by a dual-wavelength spectrophotometer at 570 nm with the reference at 650 nm.. The blank control, negative control and positive control were treated in the same manner. The cell cytotoxicity ratio of the negative control group, positive control group and sample group were determined by the following formula: Cell cytotoxicity ratio =( OD 570- OD 650)of sample / ( OD 570 OD 650) of blank control ×100.
1.3
(1)
Sensitization Test
A guinea pig maximisation test of the material identified below was conducted to evaluate the potential to cause delayed dermal contact sensitization [8]. The method of Magnusson and Kligman was employed with adaptations for a test article extract. The susceptibility of the Hartley guinea pig strain to a known sensitising agent, 1chloro-2,4-dinitrobenzene (DNCB), has been substantiated at the Testing Centre of Sanitation & Environment Technical Institute, Soochow University (SDWH) with this method. The experimental procedure was as follows: 1) Sample preparation: For each phase of this test, a ratio of 0.2 g: 1 ml (test article to volume of vehicle) was used for the test extract . The test article was extracted in 0.9% sodium chloride (SC) at 70±2ºC for 24±2 hours. 2) Reagents: 0.9%SC, Freund’s complete adjuvant (FCA), 10% sodium dodecyl sulphate (10% SDS). 3) Each extract was intrademally injected and occusively patched to ten guinea pigs (per extract) in an attempt to induce sensitization. The vehicle was similarly injected and occusively patched to five control guinea pig (per vehicle). Following a recovery period, the test and control animals received a challenge patch of the appropriate test article extract and the reagent control. All sites were scored at approximately 24h and 48h after patch removal. 4) Evaluation of results:Magnusson and Kligman grades of 1 or greater in the test group generally indicate sensitization, provided grades of less than 1 are seen in control animals. If grades of 1 or greater are noted in control animals, then the reactions of the test animals that exceed the most severe reaction in the control animals are presumed to be due to sensitization. If the response is equivocal, rechallenge is recommended to confirm the results from the first challenge. The outcome of the test is presented as the frequency of positive challenge results in the test and control animals. 1.4
Intracutaneous Irritation Test
The test article was evaluated for skin irritation in accordance with the guidelines of the ISO 10993-10:2002/Amd.1:2006 tests for irritation and delayed-type hypersensitivity [8].This study was to determine potential skin irritation after the
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patches moistened by the extract were applied to the animals’ back. Experimental Procedure was as follows: The test article was extracted in 0.9% sodium chloride USP (SC). Each extract was intrademally injected and occusively patched to ten guinea pigs (per extract) in an attempt to induce sensitization. The vehicle was similarly injected and occusively patched to five control guinea pig (per vehicle). Following a recovery period, the test and control animals received a challenge patch of the appropriate test article extract and the reagent control. All sites were scored at approximately 24h and 48h after patch removal. 1.5
Local Reaction Test After Implantation
Fix the rabbit and snip the rabbit fur on the upper back, area of 10×20cm on each side. Cleanse the exposed skin by alcohol. After local anesthesia, puncture the puncture needle carrying test sample, at 45ºangle with the skin, into the muscle, and when pumpbacking the puncture needle, leave the sample in the muscle by using the mandrin. Implant 4 test samples into the right side of each rabbit, and 4 negative controls into the left side in the same way[5]. Finishing above procedures, place rabbits back to their own cages, and observe their general condition every day. 1) Clinic observation: observe the skin reaction on the implantation spot on the 1st, 3rd and 5th days after the implantation, whether there are abnormal phenomena like bleeding, flare, necrosis and test sample ejection etc. 2) Anatomic observation: kill the rabbits in painless condition after 2, 6 and 12 weeks respectively, anatomize and observe whether there are abnormal hypodermic and muscle pathological changes, then extract muscles on the two sides of the spine and slice the myoideum of 0.5-1.0cm’s thickness, containing the test sample, place and fix it in 10% formaldehyde solution. Histopathology inspection: imbed the fixed tissue slide with paraffin wax, stain it and observe it with optical microscope; compare tissue reaction, thickness of the fiber capsular space, inflammatory corpuscles, existence of other cells, and other abnormal conditions exiting in the sample/tissue interface in the test sample with their counterparts in the control group. 1.6
Performance Test of Packaging Material
Performance test of packaging material. By consulting standards in ISO 11607-1 [9], we selected the stain leakage test, vacuum leaking test, bacterial barrier properties test,accelerated ageing test and sealing adhesion test to evaluate the performance of the packaging material before and after radiation. 1) stain leakage test:This test consists of dropping Rhodamine B solution on the sealing area and observing whether the stain can leak through the seal. 2) Vacuum leaking test:Placing packaging material in a vacuum pump, observing whether water can leak out.
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3) Bacterial barrier properties test:Bacteria were prepared by inoculating Serratia marcescens in bouillon culture medium for 24 hours at 35°C. After sterilising the packing material, we placed it on the microbench and aseptically acquired a sample. The sample was placed on the surface of a nutrient agar slide, and a 1 ml drop of Serratia marcescens solution (containing 5.6×107 cfu/ml of cells) was placed on the packing material with care to avoid leakage of the bacterial solution. The slide was covered and cultured for 24 hours at 35°C. We then observed the growth condition of the bacteria. 4) Accelerated ageing test: The packaging material was stored at 60℃ for 28 days, the accelerated ageing test of 28 days, equals to 24 monthes in a normal environment. 5) Sealing adhesion test: In this test, we made the packing material into standard size specimen and determined the sealing adhesion strength by using an XLD-A electronic tensile strength machine.
2
Results and Discussion
2.1
Bioburden and Recovery Rate
＝
Sterilisation dose setting. Adjusted average initial bacterial count of the sample was 19.48 cfu per device. The verification dose was 6.0kGy 18.5×1.08 (ZSP=1:SAL=10-2). One hundred products were radiated with the verification dose, and the sterility tests were conducted. No bacterial growth was observed in these 100 products. The minimum sterilisation dose was determined to be 8.8kGy, SAL=10-3. 2.2
Results of Cytotoxicity Tests
Cytotoxicity tests were conducted according to literature[13,14,15]. According to ISO10993- 5:2009(E)[6], if viability is reduced to < 70 % of the blank, it has cytotoxic potential. The 50 % extract of the test sample should have at least the same or higher viability than the 100 % extract; otherwise the test should be repeated. The testing sample solution was mixed with L-929 cells and incubated for 24 h. The MTT method was used to measure the cytotoxicity ratio. The cytotoxicity ratio of the 100 % extract was 92% (Table 1), demonstrating that the radiation sterilised samples were not toxic to L-929 cells. Table 1. Descriptive statistics of cell vitality
Group Blank Negative control Positive control 100% extract of the test sample
Result of Sensitisation and Intracutaneous Irritation Tests
No evidence of sensitisation was observed. Clinical observations: All animals appeared clinically normal throughout the study. Under the conditions of this study, the SC test article extracts sterilised by radiation showed no evidence of causing delayed dermal contact sensitisation in the guinea pig. Results of intracutaneous irritation tests show that the response of skin on the testing side does not exceed that on the control side. Thus, it is identified as grade 0, indicating that the applied sample does not induce irritation to skin. Thus, the radiation sterilised samples do not induce irritation to skin under the conditions of this study. 2.4
Local Reaction Test after Implantation
The clinical and anatomical results showed that no abnormal reaction was observed among test samples and negative controls, and no abnormal phenomena like hemorrhage within muscles, agnail skin, necrosis and excretion of test implants appeared. Histopathological examination was conducted as follows: tissues were fixed and embedded with paraffin, then stained and observed under a microscope to compare between test samples and negative controls in terms of tissue reaction, thickness of fibrous capsule, the existence of inflammatory cells and other cells. No abnormity appeared in test samples or tissue interface(Fig1), indicating that the test samples, after irritated under the irradiation dose, have no effect of irritation or toxicity on the muscle tissues of rabbits.
Fig. 1. HE stained muscle tissues sample of rabbits as seen by a microscope (10×10 magnification): hickness of fibrous capsule, the existence of inflammatory cells and other cells. No abnormity appeared in test samples or tissue interface.
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2.5
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Result of Performance Test of Packaging Material
Dropping Rhodamine B solution on the sealing area and no stain was observed leaking through the seal. After irradiation; the vacuum leak test of the packing material does not detect any leakage; bacterial barrier properties test after cultivation, no serratia marcescens were found on the packing material or in the bottom of the culture media, this result shows that Serratia marcescens bacteria cannot penetrate the packing material, indicating that the packing material can function as a bacterial barrier; the accelerated ageing test of 28 days, equal to 24 monthes in a normal environment, finds no bacteria; a test of the adhesion capability for the packing material’s seal was conducted before and after irradiation, the result is shown in Table 2.The average adhesion strength of the seal before irradiation was 0.09666±0.02763 N whereas the average adhesion strength of the seal after irradiation was 0.09663±0.02765 N. radiation has no distinct influence on the adhesion strength of the seal. the average tensile strength before irradiation was 0.19324±0.05528 N whereas the average tensile strength after radiation was 0.19321±0.05530 N(Table3) Table 2. Adhesion strength of the seal (pre-irradiation and post-irradiation)
The results of Cytotoxicity tests indicate that The cytotoxicity ratio of the 100 % extract was 92%. demonstrating that the radiation sterilised samples were not toxic to L-929 cells[10,11]. The Sensitisation appear that No evidence of sensitisation was observed. All animals appeared clinically normal in clinical observations throughout the study. Under the conditions of this study, the SC test article extracts sterilised by radiation showed no evidence of causing delayed dermal contact sensitisation in the guinea pig. The Local reaction test after implantation results showed that no abnormal reaction was observed among test samples and negative controls, and no abnormal phenomena like hemorrhage within muscles, agnail skin, necrosis and excretion of test implants appeared. Histopathological result observed under a microscope to compare between test samples and negative controls in terms of tissue reaction, thickness of fibrous capsule, the existence of inflammatory cells and other cells. No abnormity appeared in test samples or tissue interface, indicating that the test samples, after irritated under the irradiation dose, have no effect of irritation or toxicity on the muscle tissues of rabbits. Sensitisation, intracutaneous irritation tests, Local reaction test after implantation tests and cytotoxicity test showed that radiation sterilisation does not affect the tissue biocompatibility of the central vein catheter, indicating that the materials of the samples have no sensitization, no intracutaneous irritation, no cytotoxicity. It is very important to consider the influence of the radiation on the stability of the equipment and its texture. Both the equipment’s texture and its design contribute to its radiation stability. In our study, the test results indicate that the packing material retained its imperviousness and other beneficial properties without causing secondary pollution.
4
Conclusion
No toxic or sensitising substances or particles were released from these central vein catheter after radiation sterilisation. After simulated storage and radiation sterilisation with the setting dose, both of physicochemical properties and packaging capability of sample products were not significantly changed, indicating that the product material is relatively stable for radiation. Therefore, radiation sterilisation is a useful method to the materials of central vein catheter. Acknowledgments. We would like to thank the Construction Projects of Preponderant Discipline of Colleges in Jiangsu Province (Radiation Hematology of Blood Transformation Medicine) for financial support of this study.
References 1. Nam, K.W., Yoo, J.J., Koo, K.H., Yoon, K.S., Kim, H.J.: Optimal sterilisation method for the zirconia/alumina composites used for total hip replacements. J. Biomed. Mater. Res. B Appl. Biomater. 90, 962–966 (2009) 2. Brinston, R., Miller, A., Deeley, C.: Developments in radiation sterilisation. J. Med. Device Technol. 19, 36–37 (2008)
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3. Demirel, C., Kilçiksiz, S., Ay, O.I., Gürgül, S., Ay, M.E., Erdal, N.: Effect of N-acetylcysteine on Radiation-induced Genotoxicityand cytotoxicity in Rat Bone Marrow. J. Radiat. Res. 50, 43–50 (2009) 4. ISO11137-2 .Sterilisation of health care products, Part 2: Establishing the sterilisation dose, 5–16 (2006) 5. Hao, H.P.: Companion of biological evaluation criterion of medical devices. Standards Press of China, Beijing (2000) 6. ISO10993-5: Biological evaluation of medical devices-part5:Tests for in vitrocytotoxicity, 1–30 (2009) 7. Demirel, C., Kilçiksiz, S., Ay, O.I., Gürgül, S., Ay, M.E., Erdal, N.: Effect of N-acetylcysteine on Radiation-induced Genotoxicityand Cytotoxicity in Rat Bone Marrow. J. Radiat. Res. 50, 43–50 (2009) 8. ISO 10993-10: Biological evaluation of medical devices-part10: Tests for irritation and sensitization. 2002/Amd.1, 05–15 (2006) 9. ISO11607-1.Packaging for terminally sterilised medical devices—Part 1: Requirements for materials, sterile barrier systems, and packaging systems, 1–12 (2006) 10. Bunnak, J., Takigami, M., Ito, H., Shinozawa, T.: Gamma irradiation effects on cultured cells: investigated by the MTT method. J. Radiat. Res. 35, 205–212 (1994) 11. Holst, C.M., Oredsson, S.: Comparison of three cytotoxicity tests in the evaluation of the cytotoxicity of a spermine analogue on human breast cancer cell lines. Toxicol. in Vitro 19, 379–387 (2005)
Study of Environment Maintenance Feasibility of Polyvinyl Alcohol Juan Guo and Jin Zhang College of Mechanical Engineering, Hebei united university, Tangshan, China [email protected]
Abstract. Along with constantly emerging of the new materials and technology of package, it will cause a lot of problems in our environment. Now Incompatible views on environmental problems are environmental pollution. They include pollution of atmosphere, water bodies and soil. The research on Polyvinyl Alcohol(PVA) film is a focus these days because it has many outstanding qualities such as environment-friendly and degradability. To study the environment maintenance feasibility of water-soluble PVA in this paper. The characteristic of water-soluble PVA was summarized. To analyze the environment maintenance of water-soluble PVA by raw material preparation, production engineering, use and waste harnessing, the pattern of life cycle activity of water-soluble PVA was determined. At the sametime, the intimate relation of material development and environment maintenance was pointed out. To make a finish: the compatibility of material and environment decided the use of packaging material in market. Keywords: Water solubility, Polyvinyl alcohol, Environment, Packaging material.
1
Introduction
Now Incompatible views on environmental problems are environmental pollution. They include pollution of atmosphere, water bodies and soil. Environment pollution is a phenomenon that human discharge materials or energy in excess of its self cleaning capacity to environment directly or indirectly, which makes the quality of environment reduce and has a negative effect on human survival and development, ecological system and property. The research on PVA film is a focus these days because it has many outstanding qualities such as water solubility and degradability. I study the environment maintenance feasibility of water-soluble PVA in this paper. 1.1
Study of Environment Maintenance Feasibility of Polyvinyl Alcohol
157
(2)It is safe and convenient for application, and it can prevent the packed products from contacting the users directly during application. In addition, we could measure exactly and guard against wasting if it is used, as well as it is nontoxic and pollutionfree. (3)The water-soluble PVA film has comparatively higher mechanical performance and heat seal strength as well as outstanding gas barrier property and keeping fragrance. (4)Excellent oil, organic solvent and fat resistance. (5)Have a good quality of static electricity resistance, and when packing a powdery substance it will not absorb powder or dust.
2
The Analysis of Environment Maintenance Feasibility of PVA
2.1
Raw Material Preparation of PVA
There are usually two kinds of route to produce the raw material of PVA. One is the vinyl as raw material. Another is the acetylene (acetylene gas or calcium carbide acetylene) as raw material. Firstly, we made vinyl acetate, then made PVA. Many foreign producers mostly used ethylene to produce the raw material of PVA. Each production method has its advantages and disadvantages. The comparison of process and characteristics see table 1. Table 2 is the main technical indices comparison. Table 1. The comparison of process and characteristics
Raw material
Vinyl
acetylene gas
Calcium carbide acetylene
Ratio(Moore ratio)
Vinyl: acetate: oxygen =9:4:1.5
C2H2:acetate = 1:6~8
C2H2:acetate = 1:2~4
Catalyst composition
palladium, metals
Zn(Ac)/activated carbon
Zn(Ac)/ activated carbon
Life /month
5~6
3
5~6
One-way conversion,%
15~20
60~70
30~35
Advantages
less by-products,small equipment corrosion, high catalytic activity, good product quality
High heat utilization,cheap and easy catalyst, fewer side-effects
Mature technology, less investment, catalyst easily
Disadvantages
the precious catalyst
Acetylene cost is high
Calcium carbide has serious pollution
Precious
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㎏
Project original cost( /t)
Ethylene method
Natural method
1.88
2.01
4.5
Waste discharge
Low
Low
High
Product costs, %
Low
High
High
Total investment accounts for waste treatment, %
Low
Low
High
Total investment in equipment maintenance, %
Low
Low
High
Comprehensive consumption
energy
gas
Acetylene method
Through analysis by the listed items in table 2, I draw the conclusion: ethylene direct synthesis method has little environmental pollution, low resources consumption but higher energy utilization rate. This method deserve to be popularized and applied. 2.2
The Production Process of PVA Film
PVA is a more hydroxyl polymers. Because of its neat structure, strong hydrogen existing internal molecule and high crystallinity, make its melting temperature is higher than decomposition temperature, and production process is more difficult. Since the PVA film advented in Japan at the beginning of 1960s, the main processing methods of PVA film have: 2.2.1 Solution-Flow-Casting Method The earliest film-forming method is solution-flow-casting method. According to the producing equipment it can be divided into ring-belt cast line and turn-cylinder cast line. The stock solution of PVA film is made by dissolved and attenuat resin solution. In order to adjust the processing function, we can add some corresponding assistant in the stock solution, such as plasticizers, colorants and release agents, etc. The production process of water-soluble PVA film is: Firstly, water-soluble glue of solid content for 18%~20% was preparated. Secondly, the glue was casted and coated onto the mirror stainless steel band. Then the dry PVA film was stripped from the mirror stainless steel band. At last we put the dry film into the drying-chamber until it reached regulation moisture, and then trim and wind the film. The PVA films were obtained. The advantage of this method is the PVA film has precise thickness, perfect transparency and high gloss, while its disadvantage is the concentration of solution is low, production capacity is small, cost of equipment is big, area coverage is large, Worker labor is intensity and energy consumption is big. Thus these factors limit the popularization and application of the PVA films.
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2.2.2 Water Melting Extrusion Method Adding amount of water and plasticizer into PVA resin can reduce the melt viscosity of PVA resin and increase the plasticity. The PVA films were obtained by the melting and defoaming, then into T-helicopter extrusion, and then drying and heat-treatment. Comparison of the above two methods, it is observed that processing unit and operating conditions are different. To the latter, the solution concentration of raw resin is relatively high and the production capacity is relatively tall. 2.2.3 No Water Melting Extrusion Method The PVA films were obtained by heating and melting the PVA resin, then into Thelicopter extrusion, and then quenching. The PVA film preparated by this method has the characteristic of outstanding transparency and gloss, speedy production, adjustable film thickness. But this method is only suitable for forming orientational film. The equipment cost is high. Commonly this method was used for copolymerization colophony to become film. 2.2.4 Dry Extrusion Moulding Method The production process of water-soluble PVA film preparated by dry extrusion moulding method is: Firstly, we put the PVA resin under vacuum conditions to dry about 24h.Secondly, A certain proportion of additives, such as plasticizing modifier and film-forming agent, were added to the PVA resin and mixed evenly in high-speed mixer. Then we put to use the single-screw extruder to granulate. At last we treated the PVA granule until they get into shape. The PVA films were obtained. 2.2.5 Continuous Biaxial Orientation Method The production process of this method is: Firstly, we filter the impurities of PVA powder and PVA solution. Secondly, we put the mixed materials into twin-screw extruder and Single-screw extruder. After drying stereotypes processing, then we treated it with the longitudinal traction and transverse tensile. The PVA films were obtained. Because this technology was expensive and difficult, it was hard to be put into use for a long time. With the continuous improvement of the processing, now it not only reduce the costs but also improve the production efficiency. The economic feasibility should give affirmation, but the environment maintenance feasibility remains to discussion. 2.3
The Application of PVA Film
Environment-friendly package bags of water-soluble PVA have some advantages as follows:
① ②
The dissolving speed of water-soluble PVA film can be controlled, what’s more, it can be dissolved in cold water. It can greatly reduce the adverse impact of agricultural chemicals and industrial chemicals on the human and environment;
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③ ④
Glass contains can be instead. Reducing the costs of production and transportation, and resolving the problems of enclosing and recycling; Measure accurately, avoid production loss because of overusing or insufficiently employing agricultural chemicals. The medical package bags made by environment-friendly material of water-soluble PVA film have ideal anti-friction and environment-friendly. They have some advantages as follows:
① PVA films hardly occur electrostatic effect and can reduce dust pollution; ② The bags can be dissolved completely in water. The whole dissolution process is no residues and the water won’t be polluted; ③ They have good separate quality. As soon as products are packaged, they will
not touch with outside environment when they are circulated.
PVA film has excellent separated performance. It can keep the fragrance of packaged products and avoid the effect of outside smell. As material used to package food, it is non-poisonous and will not pollute food. More over it can prolong the period of validity of packaged food. We realize that the worth of PVA film lies on its features of low poisonousness, dissolution and biologic degradation. These prove that it has little influence on environment. And it is approved by developed countries such as America and Japan. It further illustrates that protecting environment is feasible and PVA film should be widely popularized in market. All in all, we can draw a conclusion that PVA film is non-pollution and it will protect environment. 2.4
The Waste Treatment of PVA Film
At present, the main methods of disposing waste plastic have landfill, burning and recycling. But neither of them is ideal. In common, plastic need decades or hundreds of years to degradation and become pieces which have no pollution to environment or turn into carbon dioxide and water returning to natural circulation. As for degradation mechanism, PVA films have two kinds of degradation characteristics: water degradation and biological degradation. 2.4.1 PVA Water Degradation To see from a macroscopic perspective, Almost all the water-soluble films are hydrophilic materials. There are a large number of the hydrophilic polargroup in the molecular structure. For instance, amino acids and their polymers belong to protein material, and there are lots of hydrophilic group, such as carboxyl (-COOH), amino (HnN-, n=1or2) and acylamino (-CONH-) exist the internal structure. Starch is sucrose mortierellate, and there are a lot of hydroxyl(-OH) and nitrogenous substance in molecules. PVA is a production which polyvinyl acetate is broken down by ethyl alcohol through different degree, and there are a amount of hydroxyl (-OH) and acyl group (-OCCH3) in molecules. These groups bring forth strong adhesion force
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between molecules, leading that they can not be dissolved in room-temperature and low temperature situations. To destroy the united power needs certain energy. The dissolution mechanism of water-soluble PVA film can be considered that PVA absorb amounts of water molecules in order to make the molecules expand and resolve. Then the numerous molecules are made of carbon, oxygen and hydrogen, which are resolved into CO2 and H2O. And CO2 evaporated in the air. It explains that hydrolysis products of PVA do no harm to the environment and they are environment-friendly materials. 2.4.2 PVA Biodegradable Since 1930s PVA is considered as a kind of polymers which can be broken down by living things. And some single microorganism or symbiotic population, which can deserve PVA, are separated from the nature. Although animalcules are the minimum life, like other living things, they keep close relation with the surroundings. During Resolving substrate, microorganism’s growing will be influenced by temperature, pH value, the content and kinds of sustenance and the characters of sustenance. So the resolving properties of water-soluble PVA film keep close relation with other factors, such as the degree of polymerization and alcoholysis, the distribution of hydroxyl and crystallinity. Now there are main two orientations to research PVA degradation by living things. On the one hand, change the properties of PVA to make it to be resolved by living things. On the other hand, choose a high efficiency flora for degrading PVA by means of filtering and domestication from environment. The two orientations solve the same problem in different ways. Both of them are to make PVA be degraded more easily. When obsolete PVA film is resolved by microorganism, it produces positive influence on environment as follows: (1) It will largely reduce the losing of soil moisture content. Moreover it will promote the formation of soil aggregated structure and increase the vapor permeability and moisturization. So it is beneficial to growth of plants. (2) Can improve pH value of alkaline soil and the pH value is increasing as the concentration is increasing. In addition, the proper alkaline environment has contributed to the growth of flora for degrading and improving the degradation rate. (3) Water-soluble PVA film has low toxicity to living organisms and it is hardly absorbed by gastrointestinal tract. Furthermore PVA can not be accumulated in one’s body. From all the discussions above, we can see that the abandoned and decomposed PVA film by the microbes in environment is absolutely non-poisonous and non-harmful. What’s more, it will be able to change the construction of soil. PVA is compatible well with its surroundings.
3
Conclusion
Aim at the environment maintenance feasibility of PVA film analysis, I draw a conclusion:
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(1)The direct synthesis method of the cracked ethylene to produce the raw material of PVA has the characteristic of low energy consumption and pollution. It is feasible to the environmental maintenance. (2)Choosing dry extrusion moulding method to process PVA film has the characteristic of low energy consumption, high efficiency and small investment. It is beneficial to the environmental conservation. (3)Packaging products with PVA film is not damage to consumers and the environment. (4)PVA film can be degradated by water and biology after abandoned. Final product is nontoxic and harmless carbon dioxide and water. To make a finish: the compatibility of material and environment decided the use of packaging material in market.
References 1. Sun, L.-q.: An Analysis of Polyvinyl Alcohol on its Production and Market Prospects. Techno-economics In Petrochemicals 18(3), 33–36 (2002) 2. Wang, J., Yuan, H.-l., Ma, P.-l., Li, J.: Production, Applications and Development of PVA Film. Plastics 34(2), 12–17 (2005) 3. Liu, Y.-x., Wang, X.-r., Li, X., Ding, L.-p.: A Study on the influence of PVA plastic on Soil proporties. Tobacco Science 6, 29–31 (1996) 4. Dong, L.-j.: Research on Properties of Biodegradation of PVA. Nanjing University of Science & Technolog (2005) 5. Zhang, H.-z., Liu, B.-l., Luo, R., Wu, Y.-z., Lei, D.-s.: Influence of Molecular Weight and Alcoholysis Degree of PVA on the Properties of Biodegradation. Journal of the Graduate School of the Chinese Academy of Sciences 9(5), 607–613 (2006) 6. Liu, Y.-x., Wang, X.-r.: The Study on the Effects of Soil Water-stable Aggregate Formed by PVA. Journal of Anhui Agricultural Sciences 24(3), 262–264 (1996) 7. Yang, X.-x., Wen, D.-j.: The Research Progress of Environment Impact by PVA. Journal of University of Science and Technology of Suzhou: Eng. and Technol. 1 (2005) 8. Zhang, J.-z., Wu, S.-h., Wu, C.: The Application of Starch/PVA Blend in Slow Release Fertilizer. China Plastics Industry 38(10), 60–62 (2010) 9. Jiang, X.-c., Dong, H.-y., Xie, J.-s., et al.: Research Progress in the Thermal Degradation of Poly (vinyl alcohol) and Modifications for Thermoplastic Processing. Polymer. Bulletin 10, 38–45 (2010) 10. Guo, Y.-n., Zhao, Q.-n., Cui, S.-k., et al.: Screening of a mixed culture and isolation of different strains for degradation of PVA. Journal of Xian Polytechnic University 24(4), 448–451 (2010)
Effectiveness Study of Agriculture Listed Corporation Based on BC2 Lei Chen Students’ affairs Department, Northwestern Polytechnical University, Xi’an, Shaanxi, P.R. China, 710072 {Lei Chen,chenlei}@nwpu.edu.cn
Abstract. The efficiency evaluation is one of the important things that agriculture listed corporations care about, and it is advantageous to apply the data envelopment analysis (DEA) model to corporations’ efficiency evaluation. 2
First, use the BC model, taking the 31 agriculture listed corporations as examples, to measure their synthetical efficiency, scale efficiency and technical efficiency, and to evaluate their validity. Then according to analysis, some should adjust the direction and intensity, the final simulation comparison shows the existing problems of the corporations and the corresponding solutions. 2
Keywords: DEA, BC , agriculture listed corporation, effectiveness.
1
Introduction
The agriculture economy is the base apartment of the national economy, and agriculture listed corporations are the excellent representatives in the development of the agriculture economy[1]. Meanwhile, listed corporations occupy the most capital of the industry, so the efficiency of the listed corporations is the epitome of the management level and competitive ability of the whole industry[2]. To evaluate Chinese agriculture listed corporations objectively, and point out the direction to improve, we used Data Envelopment Analysis(DEA)to evaluate and analyse 31 agriculture listed corporations which were listed in Shanghai and Shenzhen stock exchanges.
DMU to the DEA leading edge, based on a group certain input and output evaluating indexes. For its nature of the economy, comparing to the other methods[4], and we need not to determine the function relation between the input and output evaluating indexes and the compositive ratio of the input and output in advance, and it can evaluate the corporations objectively, we select DEA as the main method in this paper.
3
The Empirical Analysis
3.1
To Introduce the Indexes and Dataset
Here, an agriculture listed corporation means the one which was classified by the China Securities Regulatory Commission (CSRC). According to CSRC, there were 47 agriculture listed corporations in china, till August, 16, 2009. Because the data of 16 of these corporations are not complete, we only used the data of the rest 31 ones (see table 1) as the sample to study. To select the indexes of input and output, we can refer to the important rule of DEA theory, which is: the number of sample DMU should be at least 2 times as the number of the input and output variables together, otherwise the ability of DEA to distinguish the effectiveness will be weaker[5]. So if we want to improve the ability of DEA to distinguish the effectiveness, we must reduce the number of the input or output variables. But under the condition of small number of samples, if we delete important variables to fit the rule, the samples can not cover the information of the entirety. For these reasons, according to the experience of Xu Xusong, we selected the number of staff (per person), costs(Yuan) and the total value of fixed assets (Yuan) as the input indexes, and the operating receipt(Yuan), flowing ratio(%) and the ratio of the turnover of fixed assets(%)as the output indexes.
3.2
2
To Introduce the BC Model
In 1978, A. Charnes,W. W. Cooper and E. Rhoder got the DEA method[6] to evaluate 2
the validity of the DMU and the first DEA model, which is the C R model. After that many scholars have been perfecting the DEA models, including the BC 2
2
model[7], 2
the semi- infinite programming C W model[8] of infinite DMUs and the C WH model[9] etc.. 2
2
Here, the BC model (that’s the Input- BC model) was given by Banker,Charnes and Cooper, in 1984. We suppose that there are n agriculture listed corporations (that’ the DMU, marking the j-th DMU as DMU j , 1≤j≤n), and every agriculture listed corporation has m inputs and s outputs. Then we suppose that x ij (>0) and y ij (>0)represent the value of the i-th(i=1, 2, m) input and the value of the
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r-th (r=1, 2, s) output of DMU j separately. According to the theorem system[4] of the set of possible production, we can get the unique set of possible production of 2
BC , which is: T
n XˈY ū∑ X j j 1
So, we can get the BC
2
n
Xˈ ∑Y j
j
n
j
j 1
Yˈ ∑
j
1ˈ
j
0ˈj
1ˈ "ˈn
(1)
j 1
model[4] of DEA(Input-B C
2
model):
max( μ Y0 − μ 0 ), ) ω T X j − μ T + μ 0 ≥ 0, j = 1, , n, T ω X 0 = 1, 1 ω ≥ 0, μ ≥ 0, μ 0 ∈ E T
I BC 2
(P
(2)
And min θ ,
( DBC 2 ) I
n
∑ X jλ j ≤ θX 0 , j =1 n ∑ Y jλ j ≥ Y0 , j =1 n ∑ λ j = 1, j =1 1 λ j ≥ 0 , j = 1, , n , θ ∈ E .
(3)
In this model,if the value ofλj is random; the result we get will be the technical n
efficiency. But here we let
∑λ j =1
j
= 1 , which means many situations can appear for
which the scale benefits may increase progressively, be invariant or decrease progressively etc.. To study the effectiveness of agriculture listed corporations, according to the BC model, we got the values of the DMUs through simulating.
4
2
To Evaluate the Results of the Empirical Analysis 2
We introduced the selected dataset into the BC model, used the software of DEAP2.1 to get the result, and finally got the value of the DEA validity. Using the method of XU Bin etc., we evaluated the synthetical efficiency, scale efficiency and technical efficiency of the DUM under the hypothesis that the scale benefits is invariant and the scale benefits is variable separately[10]. The technical efficiency and scale efficiency are the subdivisions of the synthetical efficiency.
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To Analyse the Synthetical Efficiency
First, we calculated the synthetical efficiency and analyse the synthetical efficiency (see Fig.1). 1.02 1 e str 0.98 c
DMU crste
0.96 0.94
0
5
10
15
DMU
20
25
30
35
Fig. 1. The simulation chart of results of the synthetical efficiency analysis of the 31 agriculture listed corporations
From Fig.1, we know only 4 corporations’’ value of the synthetical efficiency is 1, and none of the variable is slack. This means the 4 corporations are effective according to DEA, and their input and output are the best. The synthetical efficiencies of the rest 27 ones are all less than 1, which means they are ineffective according to DEA, and they did not make the best use of the inputs, so their technology or management must be improved. According to DEA, the effective ones only take 12.9% of the entire sample, which means the integral efficiency of the agriculture listed corporations in china is low. And this is related to the low level of the intensive production of the corporations in china. From the analysis we can see that the efficiencies of each different sub-industry of agriculture are different. In the select 31 corporations, there are 14 ones engaged in planting, 4 engaged in forestry, 5 engaged in rearing livestock, and 5 engaged in fishery industry. The calculation shows that the efficiency of fishery industry is the highest, which is 0.9876, and that of forestry is 0.9833, and that of planting is 0.9823, of rearing livestock is 0.9804. Meanwhile the efficiency of the service for farming, forestry, and rearing and fishery industry is the lowest, which is 0.979. In the selected DMUs, there are only 3 corporations engaged in the service for farming, forestry, rearing and fishery industry is the lowest, and 2 of them are ST ones. So if we get rid of the influence of the ST ones, the efficiency of the service for farming, forestry, and rearing and fishery industry is the lowest should be the highest, which is 0.988. But anyhow, the efficiency of planting and rearing is the lowest. In addition, the efficiencies of corporations engaged in the same sub-industry are different. For instance, the efficiency of Longping high-tech and Denghai seed is 1, which is on the valid leading edge, while Yasheng group and Xinsai share perform worse, even they are all engaged in planting. This means the efficiencies of the agriculture listed corporations with the type of science and technology and deep process are better. The government should lead agriculture listed corporations developing into the type of science and technology and deep process, through mitigating the revenue, financial subsidy, etc..
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4.2
167
To Analyse the Scale Efficiency
Most corporations are ineffective in DEA, and the efficiencies of agriculture listed corporations in China are different, and their developments are not relatively balanced. Then we can get the scale efficiency of each corporation, listed in Fig.2. 1.005 1 0.995
el 0.99 a c s 0.985
scale
0.98 0.975 0.97
0
5
10
15
DMU
20
25
30
35
Fig. 2. The simulation chart of results of the scale efficiency analysis of the 31 agriculture listed corporations
Through analysing the scale benefits, according to Fig.2, we can see there are 6 corporations with the production way fitting for long-term, and their scale benefits are invariant, on the point of the biggest output scale. Meanwhile, there are 6 corporations with the scale benefits increasing progressively and the scale benefits of the rest 19 ones decrease progressively. For the 6 ones with the scale benefits increasing progressively, we should input more resources, and through increasing investments or publishing new stocks, we can expand the capital and enlarge the scale of the corporation, to improve the output-input ratio. For the rest 19 ones, there is no need to increase inputs, and, according to the physical truth, we should reduce the inputs properly, and adjust the capital structure, to make the best use of existing resources, and improve the efficiency of outputs. The analysis indicated that many corporations have not reached the state of scale economy. The manage level of some corporations are still low, so they can improve much. 4.3
To Analyse the Technical Efficiency
Then we analysed the data, and calculated the technical efficiency of each corporation. From Fig.3, we can see the results. 1.01 1 e str 0.99 v
vrste
0.98 0.97
0
5
10
15
DMU
20
25
30
35
Fig. 3. The simulation chart of results of the technical efficiency analysis of the 31 agriculture listed corporations
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According to Fig.2, from Fig.3, we know that 9 corporations are effective in technical efficiency, and 6 ones are effective in scale efficiency. Shunxin agriculture and the Great Northern Wilderness in northeast China are both technically effective, but not effective in scale. This means their ineffectiveness of scale leads to the ineffectiveness of the synthetical efficiency. For the corporations that are simple ineffective of technology, we should improve their production, and reinforce the management. The values of technical efficiency of about 71% of the agriculture listed corporations in China are under 1, so the corporations must try their best to improve the situation of the effectiveness in technical efficiency. 4.4
To Analyse How to Improve It
For the DMUs which are not effective in DEA, through projection analysis, we can adjust the input and output indexes, and get the improved value. This is on the basis of the rule that the projection of the DMU which is not effective in DEA is effective in DEA. Through analysing the trends of the DEA models, Ma Zanfu[11] declared that the basic reason leading to the decreasing of the scale benefits was the relative lack of some inputs, and on the basis of meeting the basic needs of the society, if we develop some departments prior, the economy will be better, or if we produce some products, we may get the scale benefits. The key to improve the efficiency of the listed corporations is intensive management, through optimizing the resource allocation. And the DEA provides references to improve the efficiency. For the corporations that are not on the effective leading edge, through adjusting the inputs and outputs, they can become relative effective. We can reduce the number of staff, if they are too many, and control the cost, if the fixed assets are not in use. At last, we can adjust the inputs and outputs of each corporation, according to the above analysis, seeing table 1. This gave managers the references to increase, decrease, or reallocate the resources. Table 1. The inputs can be reduced and the outputs can be increased
Notes: Here, x1 presents the sum of staff (per person), x2 presents the total value of fixed assets (Yuan), y1 presents the flowing ratio(%), and y2 presents the ratio of the turnover of fixed assets(%). When calculating the sum of staff (per person), we just kept the integer, the remainder was round-off as listed in table 1.
5
Conclusions
We analysed the effectiveness of the agriculture listed corporations using DEA, and pointed out that it was necessary to improve the integral efficiency of them. Meanwhile, we got the specific way to improve the effectiveness of a corporation: more than half of the 31 corporations are not effective for integral technical efficiency, so their managers need to improve the weak parts of their production and input more to manage. DEA can provide references for managers and investors in theory, but when making improving measures, we should transform to the valid direction according to the “Projection” analyse, based on different situations.
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References 1. Lin, L.: The empirical analysis of the performance of Chinese agriculture listed corporation. Survey of Chinese Vountries (6), 66–70 (2004) 2. Xu, X., Chen, M.: Dynamic Evaluation on Performance of Listed Company in Iron and Steel Industry in China Based on DEA. Technology Economic (6), 113–126 (2009) 3. Qu, J., Cui, Y., Ying, J.: Operation Efficiency Appraisal of Listing Companies in Agriculture by DEA Method. Journal of Library and Information Sciences in Agriculture (1), 79–86 (2007) 4. Wei, Q.: Data Envelopment Analysis. Science Press, Beijing (2004) 5. Banker, R.D., Charnes, A., Cooper, W.W., Swarts, J., Thomas, D.: An Introduction to Data Envelopment Analysis with Some of Its Models and Their Users. Research in Government and Nonprofit Accounting (5), 125–163 (1989) 6. Charnes, A., Cooper, W.W., Rhoder, E.: Measuring the Efficiency of Decision Making Units. European Journal of Operational Research (2), 429–444 (1978) 7. Banker, R.D., Charnes, A., Cooper, W.W.: Some Models for Estimating Technical and Scale Inefficiencies in Data Envelopment Analysis. Management Science (9), 1078–1092 (1984) 8. Charnes, A., Cooper, W.W., Wei, Q.L.: A Semi-infinite Multicriteria Programming Approach to Data Envelopment Analysis with Many Decision-Making Units.Center for Cybernetic Studies Report,CCS551 (September 1986) 9. Charnes, A., Cooper, W.W., Wei, Q.L., Huang, Z.M.: Cone Ratio Data Envelopment Analysis and Multi-Objective Programming. International Journal of Systems Science (7), 1099–1118 (1989) 10. Xu, B., Zhang, D., Wu, J., Xue, H.: Cost-effectiveness Evaluation of University Based on DEA and Its Application. Computer Simulations, 284–286 (2008); 1006-934810-0284-03 11. Ma, Z.: The trends of the DEA models. Study of Productivity 12, 26–27 (2006)
The Evolution Analysis of Resistance Genes in Sorghum Ling Jin, Li Wang, Yakun Wang, Shuai Zhang, and Dianchuan Jin* College of Sciences, Hebei United University, Tangshan, Hebei, 063009, China {jinling1257,wangyakun0}@gmail.com, [email protected], [email protected]
Abstract. Plant disease resistance genes are products of long-term interaction between plants and pathogens, and they played an important role in the process of resisting the pathogens. It has great significance for screening the plant newfunctional disease resistance genes and improving the efficiency of breeding for disease resistance by understanding the evolution of plant disease resistance genes. In this paper, we clarify the evolutionary mechanisms of resistance genes in sorghum by bioinformatics analysis. Keywords: Disease resistance genes, tandem duplication, homologous gene.
1
Introduction
Plants, like animals, are continually challenged by a myriad of potential pathogens. There is increasing evidence that defense systems of plants are at least as complex as vertebrate defense systems[1]. Unlike animals, however, plants do not have a circulatory system and therefore cannot rely on a specialized, proliferative immune system. Each plant cell has to be capable of defense, even though this defense is coordinated locally and systemically between cells. There are a variety of types of resistance genes and mechanisms, some induced and some constitutive. Often, although not always, disease resistance in plants is determined by single, usually dominant, genes[2]. The recent cloning of several such resistance genes (R genes) is providing insight into their function and evolution. The defense system of plants may be ancient and predate the evolution of the immune system; genes similar to plant R genes have been identified in mammals. Most plant disease resistance proteins contain a series of leucine-rich repeats (LRRs), a nucleotide-binding site (NBS), and a putative amino-terminal signaling domain. They are called NBS-LRR proteins. They can fight to viruses, bacteria, fungi, nematodes, insects and other diseases[3]. The disease resistance genes are always in clusters in their chromosomes, so the disease resistance genes have a special evolutionary mechanism. Classical genetic and molecular data show that genes determining disease resistance in plants are frequently clustered in the genome. Genes for resistance *
(R genes) to diverse pathogens cloned from several species encode proteins that have motifs in common. These motifs indicate that R genes are part of signal-transduction systems. Most of these R genes encode a leucine-rich repeat (LRR) region. Sequences encoding putative solvent-exposed residues in this region are hypervariable and have elevated ratios of nonsynonymous to synonymous substitutions; this suggests that they have evolved to detect variation in pathogen-derived ligands[4]. Generation of new resistance specificities previously had been thought to involve frequent unequal crossing-over and gene conversions. However, comparisons between resistance haplotypes reveal that orthologs are more similar than paralogs implying a low rate of sequence homogenization from unequal crossing-over and gene conversion. A new model is proposed which adapted and expanded from one proposed for the evolution of vertebrate major histocompatibility complex and immunoglobulin gene families. The model emphasizes divergent selection acting on arrays of solvent-exposed residues in the LRR resulting in evolution of individual R genes within a haplotype.Intergenic unequal crossing-over and gene conversions are important but are not the primary mechanisms generating variation[5-6]. In this paper, we clarify the evolutionary mechanism of resistance genes in sorghum by bioinformatics analysis.
2
Identification of Resistance Genes and Homologous Genes
First, we download the DNA sequences and the corresponding amino acid sequences of disease resistance genes in sorghum from National Center for Biotechnology Information gene database maintained by GenBank(http://www.ncbi.nlm.nih.gov/). Then we do Blastp comparison for the amino acid sequences of disease resistance genes in sorghum, and we set the value of expectation( E − value ) as 1e − 5 .The value of expectation is the reliability evaluation of score value(bitscore) in the result of Table 1. Homologous genes of partial resistance genes in sorghum
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sequence alignment. If the value of expectation is too big, the relationship between two sequences is considered to be produced randomly in statistics[7-8]. Generally, when the value of expectation is no higher than 1e − 3 , the search result is a meaningful result in statistics[9-10]. When we set the E − value as 1e − 5 , it shows that two sequences are more likely to have the evolutionary relationship. So we determine the homologous genes of disease resistance genes in sorghum. The following table is the partial results of determining the homologous genes of disease resistance genes in sorghum by running Blastp program:
3
The Dot Plots of Homologous Genes in Sorghum
we use a dot plot to map the occurrence of two similar sequences located in different genome regions. Locations along the linear sequence of genomic regions are graphed as the X-and Y-axis with each dot at an XY coordinate marking a similarity "hit" (Figure 1). The density of dots in any portion of the dot plot represents the density of matches between the genome regions being compared. If a large amount of tandem duplication has occurred in a chromosomal region, this will be visible as a densely dotted region near the main diagonal of a chromosome plotted against itself. The dot plots we present do not include the main diagonal itself. The average density at any given distance between genes can be calculated from diagonal strips through the dot plot. Dot plots of similarities in sorghum chromosomes .Dots represent BLASTP similarities. Genes are arranged uniformly in the x-axis and arranged by the physical location in chromosome in the y-axis.
Fig. 1. The dot plots of homologous genes in sorghum
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4
The Statistical Analysis of Homologous Resistance Genes
4.1
Calculation of ka , k s between Homologous Resistance Genes in Sorghum
The difference between the two protein sequences can be shown as divergence degree(divergence), which is the percentage of the different sites. The divergence degree of any coupled sequences are partly proportional to the time of separation. It can be used to detect a specific protein’s approximate average rate of mutational accumulations in the evolutionary process. According to their divergence, we know the time of occurrence of tandem duplication. So we get: k a = 2rn t ; k s = 2rs t . We calculate the values of ka , k s between homologous disease resistance gene in sorghum by using Perl programming language. The following table is the partial result of calculating the values of ka , k s between homologous disease resistance genes in sorghum: Table 2. The value of ka , k s of homologous resistance genes in sorghum
The Statistical Analysis of Homologous Resistance Genes in Sorghum
When we compare these species which have a close genetic relationship, the number of synonymous substitutions is considered as a linear increase. Because it is often
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unaffected by the role of selection effects, we use the value of k s as a measure of the time. Then we calculate the number of homologous disease resistance genes in certain range of k s . We divide the value of k s into some small intervals according to the size of k s from 0 to 6: ( 0 , 0 .1), [0 .1, 0 .2 ), [ 0 .2 , 0 .3), [5 .9 , 6 )
Then we calculate the number of homologous disease resistance genes in each interval. we use synonymous substitution rate k s as a measure of the time, and the number of homologous disease resistance genes in certain range of k s means the number of retained duplicate genes in this period . So we get the age distribution of duplicate genes (Figure 2):
Fig. 2. Statistical analysis of homologous resistance genes in sorghum
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Phylogenetic Analysis of Resistance Genes
First, we use MEGA software to do multiple sequence alignments and build phylogenetic trees by neighbor-joining method. Bootstrap tests are performed with 1000 repeats to produce percentage values, showing the stability of their topology. According to the physical location of disease resistance genes in the chromosome , we infer the nodes where tandem duplication events occur. If a pair of resistance genes have a close genetic relationship in the phylogenetic tree and their physical location is also adjacent in the chromosome, then we infer that they may be generated by the tandem duplication events. Figure 3 is the phylogenetic tree
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Fig. 3. Phylogenetic tree of homologous resistance genes in sorghum
constructed by homologous disease resistance genes in which the value of k s is less than 0.1 in sorghum. If distance of two genes is close in the phylogenetic tree, it shows that two gene sequences are more likely to have the evolutionary relationship. By searching the files which contain the location informations, we conclude that: three genes (Sb05g022785.1, Sb05g017145.1, Sb05g022790.1) labeled is not adjacent in the chromosomes, while other genes are adjacent in the chromosomes. So we infer that other genes are generated by tandem duplication events. We conclude that about 70% of genes were generated by tandem duplication events in sorghum by phylogenetic analysis. In addition, through the phylogenetic tree we also infer that the occurrence probability of tandem duplication events is related to the size of gene clusters, the greater the size of gene clusters is, the greater the occurrence probability of tandem duplication events is.
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References 1. Wang, X., Tang, H., Bowers, J.E., Paterson, A.H.: Comparative inference of illegitimate recombination between rice and sorghum duplicated genes produced by polyploidization. Genome Research, 1–8 (2009) 2. Bai, Z.G., Qu, X., Han, W., Ma, X.M., Zhao, X.M., Zhang, Z.T.: Expression of taxol resistance gene 1 correlates with gastric cancer patient clinical outcome and induces taxol resistance. Mol. Med. Report (2010) 3. Andrew, B., Steven, C., Russ, S.: Genome-level evolution of resistance gene in arabidopsis thaliana. Genetic 165, 309–319 (2003) 4. Mondragón-Palomino, M., Meyers, B.C., Michelmore, R.W., Gaut, B.S.: Patterns of positive selection in the complete NBS-LRR gene family of Arabidopsis thaliana. Genome Research 12, 1305–1315 (2002) 5. Simková, H., Safář, J., Kubaláková, M., Suchánková, P., Cíhalíková, J., Robert-Quatre, H., Azhaguvel, P., Weng, Y., Peng, J., Lapitan, N.L., Ma, Y., You, F.M., Luo, M.C., Bartoš, J., Doležel, J.: BAC libraries from wheat chromosome 7D: efficient tool for positional cloning of aphid resistance genes. J. Biomed. Biotechnol., 302543 (2011) 6. Zhou, Y.L., Xu, J.L., Zhou, S.C.: Pyramiding Xa23 and Rxo1 for resistance to two bacterial diseases into an elite indica rice variety using molecular approaches. Genetics (2009) 7. Teshima, K.M., Innan, H.: The effect of gene conversion on the divergence between duplicated genes. Genetics 166, 1553–1560 (2004) 8. Innan, H.: The coalescent and infinite-site model of a small multigene family. Genetics 163, 803–810 (2003) 9. Velasco, R., Zharkikh, A., Affourtit, J.: The genome of the domesticated apple (Malus × domestica Borkh). Nature Genetic (2010) 10. Mariana, M., Meyer, B.C., Michelmore, R.W.: Patterns of positive selection in the complete NBS-LRR gene family of arabidopsis thaliana. Genome Research 12, 1305–1315 (2002)
Evolutionary Analysis of Cellulose Gene Family in Grasses Yakun Wang1, Li Wang1, Ling Jin1, Jinpeng Wang2, and Dianchuan Jin1,* 2
1 College of Sciences, Hebei United University, Tangshan, Hebei, 063009, China School of Life Sciences, Hebei United University, Tangshan, Hebei, 063009, China {wangyakun0,jinling1257}@gmail.com, [email protected], [email protected]
Abstract. Cellulose is the main component of the plant cell walls, and it is the polysaccharide that is the most widely distributed and abundanted in nature. So far, some cellulase genes have been sequenced. In this article, I build cellulose gene family in four grasses through genetic similarity, then I do phylogenetic analysis from the aspects of the GC content, phylogenetic trees, nucleotide substitution rates and so on in order to further clarify the evolution of cellulose gene family in grasses. Research shows that grass cellulose gene family has the high GC content (about 81.3%), and that is mainly affected by the negative selection. Keywords: cellulose genes, GC content, phylogenetic tree, nucleotide substitution rates.
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Introduction
Cellulose[1] is the polysaccharide which is composed of glucose molecules, and it is insoluble in water and common organic solvents. Cellulose is the main component of the plant cell walls[2], which is the polysaccharide that is the most widely distributed and abundanted in nature, accounting for over 50% of the carbon content of the vegetable kingdom. Cellulose content closes to 100% in cotton, which is the most natural source of pure cellulose. In addition, hemp, rice straw, bagasse, etc. are rich sources of Cellulose, and cellulose is an important paper-making raw material. Cellulose-based products are widely used in plastics, explosives, electrical and scientific equipments and so on. Dietary celluloses also play an important role on human health. So far, some cellulase genes[3] have been cloned from several species of fungi and cells, and most of the nucleotide sequences were sequenced. In this article, I determine cellulose genes’ homologous genes in four grass species, and then build cellulose gene family in grasses to further clarify the evolution of this family.
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Cellulose Genetic Data and Gene Similarity Search
In this article, I build cellulose gene family in four grasses through genetic similarity, then clarify the evolution of cellulose gene family in grasses. 2.1
Download Cellulose Genetic Data
First, I obtain some cellulose-related gene names through reading a lot of papers, and their corresponding gene sequence data and gene annotation files were got from NCBI (http://www.ncbi.nlm.nih.gov/) .The files were saved with fasta format. Second, the protein sequence alignment has the high sensitivity[4] and is easier to find distantly related sequences, so it is necessary to translate gene sequences to amino acid sequences. This requires the Perl programming language[5] to achieve conversion between the gene sequences and protein sequences. 2.2
Gene Similarity Search
The embodiment of sequence similarity[6] bases on pairwise sequences, which is that the known protein sequences are compared with protein sequence databases to identify sequence similarity. And the main purpose is to clarify the homology between sequences, and to predicte structure and function of new sequences from the known. Now the algorithm of sequence analysis is dynamic programming algorithm, whose basic idea is to decompose the problem into smaller, similar sub-problems, and produce optimal solution by solving these sub-problems. BLAST package is currently the most extensive tool of sequence similarity, and it is very fast and based on rigorous statistical basis. This article does BLASTP comparison between the translated cellulose protein sequences and protein sequences of four grasses to pr edict potential chromosome genes[7]. The expectation ( E − value ) between chromosome genes is set 1e − 5 . When the expectations are not higher than 1e − 3 , we think that search results have statistical significance, so the possibility of the evolutionary relationship between two gene sequences is very large, and we get the set of high genetic similarity. These similar genes can be roughly seen as the cellulose gene family analyzed. The following table shows some results obtained after treatment: Table 1. Potential homologue genes of cellulose genes(Part of the table)
Evolutionary Analysis of Cellulose Gene Family in Grasses
I do phylogenetic analysis from the aspects of the GC content, phylogenetic trees, nucleotide substitution rates and so on in order to further the evolution of cellulose gene family in grasses 3.1
GC Content
The proportion of guanine and cytosine is considered GC content[8] in DNA. In the double-stranded DNA, adenine divided by thymine (A / T), and guanine divided by cytosine (G / C) is 1. However, (A + T) / (G + C) is different. If GC content is higher, DNA density is higher, and heat is not easy to make it denaturation. In this article, GC content of cellulose gene family in grasses is given:
1.2 1 t 0.8 n e c n 0.6 o c C G 0.4 0.2 0 0
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cds
Fig. 1. GC3 content of cellulose gene family in grasses
From the figure, we can know that GC content especially at the third codon sites (GC3)of about two-thirds cellulose genes in grasses is above 80%, and the average of GC content is about 81.3%, So grass cellulose genes show high GC content, like many other grass genes. So cellulose gene family has relatively high GC content. 3.2
Construction of Phylogenetic Tree
Generally speaking, the quality of phylogenetic tree[9] depends on the accuracy of the distance which can be both of relative substitution rate and genetic distance or evolutionary distance. Matching method[10] (UPGMA) is the first method of distance matrix, and it is the easiest way, then many other methods are given based on this method. The basic idea(take four species for example): first, the distances between the
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pair-wise comparisons are arranged in matrix, we find the smallest distance (such as D34 ) as the first expectation, then the two species are merged into a new group to build a new matrix. The distances between new group and the other two species are calculated with the formula D1(34) = ( D13 + D14 ) / 2 and D2(34) = ( D23 + D24 ) / 2 , then the second minimum distance is found. This successive merges until the entire species into one large group, and the structure tree is completed. To characterize the evolution of cellulose genes, we aligned the sequences and constructed gene trees. The following is a phylogenetic tree of cellulose gene family in grasses(score not less than 500):
Fig. 2. Construction of phylogenetic trees (Score ≥ 500)
It can be seen from the figure, grass cellulose genes are clearly divided into three groups. We know genetic relationship of these genes is near or far and how they evolved to get them from the tree structure. The number of rice cellulose genes is relatively small, and they disperse distribution in three main branches of phylogenetic trees, indicating that these rice genes are distantly related, while the other three species (sorghum, maize, etc)were equally distributed in the evolutionary tree branches.
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Synonymous Substitution Rate ( K S ) and Nonsynonymous Substitution Rate ( K A )
That the changes of codons do not cause the changes of corresponding amino acid changes (many codons can encode the same amino acids, and these codon mutations do not affect the amino acid) is called synonymous substitutions[11], whereas is called nonsynonymous substitution[11]. Generally speaking, we believe that synonymous substitution is not affected by natural selection, and nonsynonymous substitution is affected by natural selection. In the evolutionary analysis, it is very necessary to understand synonymous substitution rate[12] and nonsynonymous substitution rate. We calculate synonymous substitution rate( K S ), nonsynonymous substitution rate( K A ) and K A / K S by programming . If K A / K S > 1 , there is a positive selection
effect[13]; if K A / K S = 1 , there is a neutral selection effect; if K A / K S < 1 , there is a negative selection effect. Then judge whether selective pressure acts on the protein-coding genes through analyzing values of K A / K S , the following is some of the results obtained. 4 3.5 3 s k / a k
2.5 2 1.5 1 0.5 0
0
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Fig. 3. K A / K S of grass cellulose genes
It can be seen from the figure, grass cellulose genes have about 70% of the genes who satisfy the criterion K A / K S < 1 , and the average of all the grass cellulose genes is about 0.84, which can basically state that the grass cellulose families mainly affeceted by the negative selection[14].
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Conclusion
The number of grass cellulose gene families is very large, and from evolutionary analysis, we know that grass cellulose gene family has the high GC content (about 81.3%); phylogenetic tree is divided into three branches obviously, indicating that these distantly related genes may differ in functional expression; and grass cellulose genes have about 70% of the genes who satisfy the criterion K A / K S < 1 , basically stating that the grass cellulose families mainly affeceted by the negative selection.
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References 1. Wendel, J.F.: Genome evolution in polyploids. Plant Mol. Biol. 42, 225–249 (2000) 2. Doblin, M.S., Kurek, I., Jacob-Wilk, D., Delmer, D.P.: Plant Cell Physiol. 43, 1407–1420 (2002) 3. Guyot, R., Keller, B.: Ancestral genome duplication in rice. Genome 47, 610–614 (2004) 4. Persson, S., Wei, H.: Identification of genes required for cellulose synthesis by regression analysis of public microarray data sets. PNAS 102, 8633–8638 (2007) 5. Hamann, T., Osborne, E., Youngs, H.L., Misson, J., Nussaume, L., Somerville, C.: Global expression analysis of CESA and CSL genes in Arabidopsis. Science 11, 279–286 (2004) 6. Paredez, A., Somerville, C.R., Ehrhardt, D.: Dynamic visualization of cellulose syntha demonstrates functional association with cortical microtubules. Science 312, 1491–1495 (2008) 7. Wang, X., Shi, X., Li, Z., Zhu, Q., Kong, L., et al.: Statistical inference of chromosomal homology based on gene colinearity and applications to Arabidopsis and rice. BMC Bioinformatics 7, 447 (2006) 8. Thompson, J.D., Higgins, D.G., Gibson, T.J.: CLASTALW: Improving the sensitivity of progressive multiple sequence alignment through sequence weighting, positions-specific gap penalties and weight matrix choice. Nucl. Acids. Res. 22, 4673–4080 (1994) 9. Saitou, N., Nei, M.: The neighbor-joining method: A new method for reconstructing phylogenetic trees. Mol. Biol. Evol. 4, 406–425 (1987) 10. Huelsenbeck, J.P., Crandall, K.A.: Phylogeny estimation and hypothesis testing using maximum likelihood. Annu. Rev. Ecol. Syst. 28, 437–466 (1997) 11. Lynch, M., Conery, J.S.: The evolutionary fate and consequences of duplicate genes. Science 290, 1151–1155 (2000) 12. Amor, Y., Haigler, C.H.: A membrane-associated form of sucrose synthase and its potential role in synthesis of cellulose and callose in plants. Science 92, 9353–9357 (2008) 13. Green, P., Selker, J.M.L.: Mutual alignments of cell walls, cellulose and cytoskeletons: their role in meristems 82, 303–322 (2009) 14. Vandepoele, K., Saeys, Y., Simillion, C., Raes, J.: The automatic detection of homologous regions (ADHoRe) and its application to microcolinearity between Arabidopsis and rice. Genome Res. 12, 1792–1801 (2008)
Application of Attributes Reduction Based on Rough Set in Electricity Distribution Dajiang Ren Zhangjiakou City, Power Supply Bureau Zhangjiakou Hebei 075000, China
Abstract. Rough set is a generalization of crisp rough set to deal with data sets with real value attributes. Attribute reduction is very important in rough setbased data analysis because it can be used to simplify the induced decision rules without reducing the classification accuracy. The notion of reduct plays a key role in rough set-based attribute reduction. In rough set theory, a reduct is generally defined as a minimal subset of attributes that can classify the same domain of objects as unambiguously as the original set of attributes. Experimental results imply that our algorithm of attribute reduction with distribution of electricity feasible and valid. Keywords: Rough Set, Attribute Reduction, Distribution of Electricity.
1
Introduction
The rough set theory proposed by Pawlak (1982) provides an effective tool for extracting knowledge from data tables. As noted in Pawlak (1991), knowledge is deep-seated in the classification capabilities of human beings. A classification is simply a partition of a universe. Thus, in rough set theory, objects are partitioned into equivalence classes based on their attribute-values, which are essentially functional information associated with the objects. Many databases only contain functional information about objects; however, data about the relationships between objects has become increasingly important in decision analysis[1]. A remarkable example is social network analysis, in which the principal types of data are attribute data and relational data .To represent attribute data, a data table in rough set theory consists of a set of objects and a set of attributes, where each attribute is viewed as a function from the set of objects to the domain of values of the attribute. Hence, such data tables are also called functional information systems (FIS), and rough set theory can be viewed as a theory of functional granulation. In recent years, rough sets have been successfully used in many areas such as pattern recognition, machine learning, and artificial intelligence.
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attributes [2]. An information table represents all available information and knowledge. That is, objects are only perceived, observed, or measured by using a finite number of attributes. Rough set theory is the main ideas in keeping the classification ability, under the precondition of constant through knowledge reduction, export issue the decisionmaking and classification rules. not complying with the LNCS style will be reformatted. An information table is the following tuple:(1) where U = { x1 , x 2 , x n } is a finite nonempty set of objects, Ω = { A1 , A2 Am } is a finite nonempty set of attributes,
f : U × Ω → V , f ( xi , A j ) ∈ V j is
V={ V1 , V 2 Vm }is a nonempty set of values ,and
an information function that maps an object in U to exactly one value in V. In classification problems, we consider an information table of the form
I =< U , Ω,V , f >
.
(1)
where Ω = { A1 , A2 Am } is a set of condition attributes describing the objects, and
{ A1 , A2 Am } is a decision attribute that indicates the classes of objects. In general, we may have a set of decision attributes. A table with multiple decision attributes can be easily transformed into a table with a single decision attribute by considering the Cartesian product of the original decision attributes. 2.1
R-Lower Approximation, R-Upper Approximation
In this section, we will review several basic concepts in rough set theory. Throughout this paper, we suppose that the universe U is a finite nonempty set. Let U be a finite and nonempty set called the universe and R=U × U an equivalence relation on U .Then K=(U,R) is called an approximation space [3]. The equivalence relation R partitions the set U into disjoint subsets. This partition of the universe is called a quotient set induced by R, denoted by Y= U/R. It represents a very special type of similarity between elements of the universe. If two elements X,Y ∈ U,X ≠ Y belong to the same equivalence class, we say that X and Y are indistinguishable under the equivalence relation R, i.e., they are equal in R. We denote the equivalence class including X by Y=U/R. Each equivalence class Y=U/R may be viewed as an information granule consisting of indistinguishable elements [4]. The granulation structure induced by an equivalence relation is a partition of the universe. Given an approximation space K=(U,R) and an arbitrary subset X U, one can construct a rough set of the set on the universe by elemental information granules in the following definition:
⊆
R X = {Y ∈ U R : Y ⊆ X } .
(2)
R X = {Y ∈ U R : Y X ≠ φ } .
(3)
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Where (2)and (3) are called R-lower approximation and R-upper approximation with respect to R, respectively. The order pair ( R X , R X ) is called a rough set of X with respect to the equivalence relation R. Equivalently, they also can be written a:
R X = {Y ∈ U R : Y ⊆ X } .
(4)
R X = {Y ∈ U R : Y X ≠ φ} .
(5)
Each of feature selection method preserves a particular property of a given information system, which is based on a certain predetermined heuristic function. In rough set theory, attribute reduction is about finding some attribute subsets that have the minimal attributes and retain some particular properties. For example, the dependency function keeps the approximation power of a set of condition attributes. To design a heuristic attribute reduction algorithm, three key problems should be considered, which are significance measures of attributes, search strategy and stopping (termination) criterion. As there are symbolic attributes and numerical attributes in real-world data, one needs to proceed with some preprocessing. Through attribute discretization, it is easy to induce an equivalence partition. However, the existing heuristic attribute reduction methods are computationally intensive which become infeasible in case of large-scale data. As already noted, we do not reconstruct significance measures of attributes and design new stopping criteria, but improve the search strategies of the existing algorithms by exploiting the proposed concept of positive approximation 2.2
Theorem
Let X and Y be binary relations on U, then we have the following properties:
3
RX ⊆ X ⊆ RX .
(6)
R( X Y ) = R X R X .
(7)
R( X Y ) = R X RY .
(8)
Forward Attribute Reduction Algorithm
In rough set theory, to support efficient attribute reduction, many heuristic attribute reduction methods have been developed in which forward greedy search strategy is usually employed, cf[5]. In this kind of attribute reduction approaches, two important measures of attributes are used for heuristic functions, which are inner importance measure and outer importance measure. The inner importance measure is applicable
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to determine the significance of every attribute, while the outer importance measure can be used in a forward feature selection. It is deserved to point out that each kind of attribute reduction tries to preserve a particular property of a given decision table.At this first attribute set to generation through candidate attribute evaluation through attribute suitblity to stopping criterion continue to generation.At last stopping criterion output to an attribute reduct let is all. In each forward greedy attribute reduction approach, starting with the attribute with the maximal inner importance, we take the attribute with the maximal outer significance into the attribute subset in each loop until this feature subset satisfies the stopping criterion, and then we can get an attribute reduct.Formally a forward greedy attribute reduction algorithm can be written as follows. 3.1
Representative Significance Measures of Attribute
Given any definition of attribute reduct and heuristic function, using the above attribute reduction framework, one can heuristically find an attribute reduct (a feature subset) that preserves a particular property of a decision table. If we survey the attribute reduct from the viewpoint of rough classifiers, these attribute reduction algorithms may lead to overfitting in the approximation of concepts, which will weaken the generalization ability of rough classifiers induced by the attribute reducts obtained. This problem could be caused by two cases. One is that the attribute subset induced by an attribute reduction algorithm with forward greedy searching strategy may be redundant. That is to say, there are some redundant attributes in the attribute subset obtained from the definition of a given attribute reduct. The other is that the definition of each of attribute reductions does not take into account the generalization ability of the rough classifier induced by the attribute reduct obtained. These two situations yield the same overfitting problem as a decision tree does when the tree has too long paths. Hence, it is very desirable to solve the overfitting problem of feature selection for learning a rough classifier in the framework of rough set theory. This issue will be addressed in future work. For efficient attribute reduction, many heuristic attribute reduction methods have been developed in rough set theory,see[6].For convenience, as was pointed out in the introduction part of this paper, we only focus on the four representative attribute reduction methods here. Given a decision table S one can obtain the condition partition U/C = { x1 , x2 , xm } and the decision partition U/D = { y1 , y2 , yn }. Through these notations, in what follows we review four types of significance measures of attributes. The idea of attribute reduction using positive region was first originated by Grzymala-Busse in Refs[7].And the corresponding algorithm ignores the additional computation of choice of significant attributes. Hu and Cercone proposed a heuristic attribute reduction method, called positive-region reduction , which remains the positive region of target decision unchanged[8]. In this method, the significance measures of attributes are defined as follows.
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3.2
Attribute Reduction Algorithm Based on the Positive Approximation
The objective of rough set-based feature selection is to find a subset of attributes which retains some particular properties as the original data and without redundancy. In fact, there may be multiple reducts for a given decision table. It has been proven that finding the minimal reduct of a decision table is a NP -hard problem. When only one attribute reduct is needed, based on the significance measures of attributes, some heuristic algorithms have been proposed, most of which are greedy and forward search algorithms. These search algorithms start with a nonempty set, and keep adding one or several attributes of high significance into a pool each time until the dependence has not been increased. From the discussion in the previous subsection, one knows that the rank preservation of attributes in the context of the positive approximation. Hence, we can construct an improved forward search algorithm based on the positive approximation, which is formulated as follows. In this general algorithm framework, we denote the U
evaluation function (stopcriterion) by EF (B, D) = EF
U
(C, D). For example, if one
adopts Shannon’s conditional entropy, then the evaluation function is HU U
HU (C, D). That is to say, if EF attribute reduct.
4
U
(B, D) = EFU
U
U
(B, D) =
(C, D), then B is said to be an
The Uncertain Information Distribution of Electricity
The electricity sector has been witnessed with considerable deregulation and liberalization in many countries over the past couple decades, such as Australia, Norway, New Zealand, Sweden, Switzerland, and the U.K. After the introduction of competition into the generation sector, regulatory reform and incentive regulation have also been introduced into the electricity distribution sector. With the planned introduction of the new “Amended Electricity Act” that has been ruled upon by the Executive Yuan, but still under legislative discussion, Taiwan's government plans to liberalize the distribution of electricity by privatizing existing state-owned distribution utilities and permitting new entrants, aiming to improve the sector's efficiency. This policy is particularly important for Taiwan which lacks abundant energy resources. To ensure the electricity distributors' having a higher operating efficiency after liberalization, there are two essential questions should being examined carefully. In other words what is the optimal scale of an electricity firm? Utilizing the historical cost and output information of existing distribution firms coupled with predictions on electricity usage, we can assess the optimal size of the service territory by using an average cost distance function approach or data development analysis approach from the economical perspectives. Most important and hotly debated is the second issue, that is, the efficiency estimation of distribution companies. Even though the electricity distribution industry has been liberalized, the electricity distribution utilities will have strong market power within their service territories as usual, indicating a rate regulation by the authorities is necessary. There are several regulatory practices in the electricity market, such as
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yardstick competition and incentive regulation. Basically, we can implement those models in practice based on benchmarking — that is, measuring a firm's efficiency against a reference firm's performance. According to the estimated X-inefficiency which is the deviation from the optimal point on the cost (production) frontier to the real cost (production) level, the regulatory commission can reward or punish firms from a benchmarking application. Therefore, the reliability of the efficiency score is particularly crucial in regulatory practices. 4.1
Algorithm Steps
A general improved feature selection algorithm based on the positive approximation. To support the substantial contribution of the general improved attribute reduction algorithm based on the positive approximation, we summarize three factors of speedup of this accelerator as follows. (1) One can select the same attribute in each loop of the improved algorithm and that of the original one. This provides a restriction of keeping the result of an attribute reduction algorithm. (2) Computational time of significance measures of attributes is significantly reduced, which is because that it is only considered on the gradually reduced universe. It is one key factor of the accelerated algorithm. (3) Time consumption of computing the stopping criterion is also significantly reduced via gradually decreasing the size of data set. This is the other important factor of the improved algorithm. Based on the above three speedup factors, we draw such a conclusion that: the general modified algorithm can significantly reduce the computational time of each existing attribute reduction algorithm while producing the same attribute reducts and classification accuracies as those coming from the original ones. It is deserved to point out that each of these modified algorithms can not solve the over fitting problem in the approximation of concepts and improve the generalization ability of the rough classifier induced by the obtained attribute reduct. The general improved algorithm only devotes to largely reducing the computational time of original attribute reduction algorithms (see Algorithm 1)[9]. 4.2
Experimental Analysis
Table 2 shows that the reduction found by using the TL method is smaller than that found by using the MIN method in the dataset case, whereas the reduction found by using the TL method is bigger than the one found by using the MIN method in the dataset case. Table 3 shows that the classification quality of the smaller reduction is not worse or even better than that of the bigger reduction. These show that the TL method is more effective than the MIN method in the dataset case, whereas the MIN method is more effective than the TL method in the dataset case. It is easy to draw a conclusion that the TL and MIN methods have different results for attribute reduction on the same dataset. Both Tables 2 and 3 shows that different triangular norms work well on different types of datasets, and the different triangular norms do affect the performance of attribute reduction.
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Number of condition attributes 5 11 13 6 9
Condition attributes 15 30 39 18 16
Table 2. Comparison of the size of the reductions obtained by the TL and MIN methods Objects number Tae 151 Class 214 Wine 178 Bupa 345 Doe 520
Method TL MIN TL MIN MIN
Reduction size 10-13 14 16 269 10-12
Table 3. The detailed comparison of the reductions obtained by the TL and MIN methods Objects number Tae 151 Class 214 Doe 520
5
Number of condition attributes 5 11 9
Condition attributes 15 30 16
Conclusion
This paper revisits attribute reduction based on fuzzy rough sets into distribution of electricity. Different types of fuzzy approximation operators can be defined by using two pairs of fuzzy approximation operators and various t-norms. Concerning attribute reduction using different fuzzy approximation operators are established, we have found that given certain conditions the same solution can be achieved, which also answer if a reduced subset of attributes may further be downsized. They are helpful in guiding the practice of attribute reduction based on fuzzy rough sets. Simulation results for the given illustrative distribution of electricity examples demonstrate the effectiveness and correctness of the theoretical contributions proposed in this paper.
References 1. Bhatt, R.B., Gopal, M.: On fuzzy-rough sets approach to feature selection. Pattern Recognition Letters 26, 965–975 (2009) 2. Bazan, G.: A comparison of dynamic and non-dynamic rough set methods for extracting laws from decision tables. In: Polkowski, L., Skowron, A. (eds.) Rough Sets in Knowledge Discovery 1: Methodology and Applications. Studies in Fuzziness and Soft Computing, pp. 321–365. Physica-Verlag, Heidelberg (2008)
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3. Erdogdu, E.: Electricity demand analysis using cointegration and ARIMA modeling,a case study of Turkey. Energy Policy, 112–946 (2010) 4. Wang, C., Jia, Q.Q., Li, X.B., Dou, C.X.: Fault location using synchronized sequence measurements. Int. J. Elect. Power Energy Syst. (2010) 5. Jung, H., Park, Y., Han, M., Lee, C., Park, H., Shin, M.: Novel technique for fault location estimation on parallel transmission lines using wavelet. Int. J. Elect. Power Energy Syst., 76–82 (2007) 6. Kryszkiewicz, M.: Rules in incomplete information systems. Information Sciences 113, 271–292 (1999) 7. Kryszkiewski, M.: Comparative study of alternative type of knowledge reduction in inconsistent systems. International Journal of Intelligent Systems, 105–120 (2001) 8. Mi, J.-S., Wu, W.-Z., Zhang, W.-X.: Approaches to knowledge reductions based on variable precision rough sets model. Information Sciences, 255–272 (2004) 9. Mordeson, J.N.: Rough set theory applied to (fuzzy) ideal theory. Fuzzy Sets and Systems 121 (2010) 10. Mi, J.S., Wu, W.Z., Zhang, W.X.: Approaches to knowledge reduetion based on variable precision rough set model. Information Sciences 159(3-4), 255–272 (2004) 11. Gong, Z.T., Sun, B.Z., Shao, Y.B., et al.: Variable Preeision rough set model based on general relation. In: Proeeedings of 2004 Intemational Conference on Machine Learning and Cybemetics, Shanghai, China, pp. 2490–2494 (2004)
Application of Least Squares Support Vector Machine in Fault Diagnosis Yongli Zhang1, Yanwei Zhu2, Shufei Lin3, and Xiaohong Liu1 1
2
College of Light Industry, Hebei United University, Tangshan, China Department of Mathematics and Information science, Tangshan Normal University, Tangshan, China 3 Department of Computer, The North University for Ethnics Yinchuan, China {zhyl01,zhyw79,linshufei197937}@163.com
Abstract. In daily life fault diagnosis is widely used production. With the rapid development of science and technology, the new high-tech products emerged. It is not enough data of samples. Conventional approach is ineffective. It is need to find a good method. The least squares support vector machine algorithm and the proximal of support vector machine applied to fault diagnosis. Through experiments when learning samples is not enough, equipment failure does not reduce and the classification accuracy has increased even. On fault diagnosis the training speed has been to improve and the cost of building has been reduced. Improve overall system performance of fault diagnosis. Keywords: Support Vector Machine, Least squares, Proximal Support Vector Machine, Fault Diagnosis.
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recognition - support vector machine (Support Vector Machine, SVM) [1]. Its appearance, this gap just is made up. SVM is a learning algorithm based on statistical learning theory. It solves the problem of small sample study. Using support vector machines features, features are extracted. Normal and abnormal data were distinguished. In order to take effective steps to avoid further abuse the equipment. The SVM algorithm is applied to fault diagnosis. Through experiments when learning samples is not enough, equipment failure does not reduce and the classification accuracy has increased even. On fault diagnosis the training speed has been to improve and the cost of building has been reduced. Improve overall system performance of fault diagnosis.
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Support Vector Machines
Let the sample set is linearly separable {( x1 , y1 ), ( x2 , y2 ), , ( xn , yn )}, x ∈ R d ,
y ∈ {1, −1} . Categories surface equation to meet:
w ⋅ xi + b ≥ 1
yi = 1
w ⋅ xi + b ≤ −1
yi = −1
(1)
To make the maximum interval classification, separating hyperplane problem will be transformed the quadratic programming problem. 1 1 2 w = ( w ⋅ w) 2 2 yi ( w ⋅ xi ) − b ≥ 1, i = 1, 2, , n
min Φ ( w, b) = s.t.
(2)
Where : n is the number of training samples. The above problem is known as the original problem. The problem can be solved by a standard quadratic programming. Using Lagrange optimization, problem is transformed into the original dual problem : n 1 n n α iα j yi y j ( xi x j ) − α i 2 i =1 j =1 i =1
min
α
n
s.t.
αi yi = 0 i =1
(
Solved α * = α1* , , αl* than 0
α *j
)
T
(3)
α i ≥ 0 i = 1, 2, , n n
,using w* = yiα *xi ,select
(4)
α * component is greater
i =1
Corresponding to the sample ( x j , y j ) (SV corresponding to sample), n
(
)
According to b* = y j − yiα i* xi ⋅ x j ,Calculate w and b , determine the optimal
(
)
i =1
hyper plane w* ⋅ x + b* = 0 ,Decision function: f ( x) = sgn( w* ⋅ x + b* ) or
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n f ( x) = sgn α i* yi ( x ⋅ xi ) + b* . i =1
(5)
Samples of α * ≠ 0 are called support vectors, sign(*) is Sign function, b is threshold of classification, x is sample of testing. When non-linear, the introduction of penalty coefficient C and Slack variable ξi , Then (2) becomes min
w,b,ξ
s.t.
n 1 2 w + C ξi 2 i =1
(6)
yi (( w ⋅ xi ) + b) ≥ 1 − ξi , ξi ≥ 0, i = 1, 2, , n
Kernel functions are leaded into linearly inseparable samples. The nonlinear transformation on low-dimension is shined upon high dimensional feature space. Problem of classification is solved on high-dimensional feature space. If dot product ( xi ⋅ x) is instead of the kernel function K ( xi ⋅ x ) .x → ϕ ( x) .Where: K ( xi ⋅ x) = ϕ ( xi ) ⋅ ϕ ( x) . So equation (6) of the quadratic programming problem change into a dual problem.
Fig. 1. Support vector machine structure Solve the coefficients α i , As long as the search maximum of function
Application of Least Squares Support Vector Machine in Fault Diagnosis n 1 n n ( ) α α y y K x x − i j i j i j αi 2 i =1 j =1 i =1
min
α n
s.t.
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αi yi = 0 0 ≤ αi ≤ C i = 1, 2,, n
(7)
i =1
Solving function on a segment-type[2][3] n
f ( x) = sgn( yiα i* K ( xi , x) + b* )
(8)
i =1
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Least Squares Support Vector Machine
In the feature space, LS-SVM takes the form y = sgn( wT ϕ ( x) + b)
(9)
Where: the nonlinear mapping ϕ ( x) maps the input data into a high dimensional feature space whose dimension can be infinite. To obtain a classifier, LS-SVM solves the following optimization problem 1 γ l min( wT w + ei2 ) 2 2 i =1 s.t.
yi = w ϕ ( xi ) + b + ei T
(10)
i = 1, , l
Its Wolfe dual problem is min(
l α2 l 1 l α iα jϕ ( xi )T ϕ ( x j ) + i − α i yi ) 2 i , j =1 i =1 2γ i =1 l
s.t.
(11)
αi = 0 i =1
Including in (11) the bias b, we can eliminate the equality constraint and obtain min(
l l α i2 l 1 l T ϕ x ϕ x + − α i yi + b α i ) . α α ( ) ( ) i j i j 2 i , j =1 i =1 2γ i =1 i =1
(12)
The form ϕ ( xi )T ϕ ( x j ) in (12) is often replaced with a so-called positive definite kernel function k ( xi , x j ) = ϕ ( xi )T ϕ ( x j ) . According to Mercer’s theory, any positive definite kernel function can be expressed as the inner product of two vectors in some feature space and therefore can be used in LS-SVM. Among all the kernel functions,
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x−x 2 i is the most popular choice. For a new Gaussian kernel k ( xi , x j ) = exp − 2 σ 2 sample x, we can predict its label by l
f ( x) = sgn( wT ϕ ( x) + b) = sgn( α i k ( x, xi ) + b)
(13)
i =1
Where: α and b is the solution of (12) [3][4][5]. Least squares support vector machines need to solve convex quadratic programming problem the only equality constrained. Therefore, it is relatively simple to solve. Equivalent a linear equation is solved. Time training of SVM is saved. Its weakness is not accurate. So Fung G, Mangasarian O L proposed methods which improved Least squares support vector machines[6].
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Proximal Support Vector Classification was Proposed (PSVC)
4.1
Proximal Support Vector Machines
1 2 b was added in Proximal Support Vector Classification. It is a strictly convex 2 quadratic programming problem. Given training set T = {( x1 , y1 ), ( xn , yn )} ∈ ( R d × Y ) n , xi ∈ R d , yi ∈ Y = {1, −1}, i = 1, 2, , n ; Select the appropriate kernel function K ( x, x′) , Penalty parameter C > 0 ; Construct and solve the problem of unconstrained 1 C n 2 ( w + b 2 ) + ηi2 2 2 i =1
min
w,b ,η
s.t.
(14)
yi (( w ⋅ ϕ ( xi )) + b) = 1 − ηi , i = 1, 2, , n
Equivalent strictly convex unconstrained quadratic programming problem min α
1 n n 1 n 2 n α iα j yi y j ( K ( xi , x j ) + 1) + αi − αi 2 i =1 j =1 2C i =1 i =1
f ( x) = sgn( yiα i* K ( xi , x) + b* ) [3][6][7]. i =1
(16)
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Error Correcting Output Coding Method of Multi-classification
To M classification problem, L two-classification are constructed. Obtain M × L order coding matrix S = ( sij ) M × L .The elements of matrix are 1 and −1 . For the positive class points sij = 1 , for the negative class points sij = −1 .
Then L decision functions are constructed on two-class. jth two-class problems decision function f j ( j = 1, 2, , L) . If you want to determine the ownership of an input x,L-dimensional row vector ( f 1 ( x), , f L ( x)) was obtained by L decision functions. Then L-dimensional vector compare with code matrix S. In the actual calculation the recent row vector ( f 1 ( x), , f L ( x)) was found from coding matrix S. Enter x to be convicted of belonging to the category corresponding to the line. Close to the level of decision uses Hamming distance. d (u, v) is L-dimensional vector u = (u1 , , ul )T and v = (v1 , vL )T . d (u , v) = {i | ui ≠ vi }
(17)
Where | * | are the number of elements in the collection *. Error correcting output coding algorithm flow sorter (1)Given the training set of M class problem T = {( x1 , y1 ), , ( xl , yl )} , xi ∈ R d , yi ∈ {1, , M }, i = 1, 2, , l ;
(18)
(2) Constructed M × L order code matrix S; (3)According constructed L two classification problems, According to i (i = 1, , L) column of S constructed i-a two types of classification problem, the problem is the input from the S class points the first i elements in a column corresponding to the composition of various types of all input and negative input from the class point of the first S i column elements corresponding to various types of all input components. (4)Using of two types of support vector machines find the decision function: 1 f ( x), , f L ( x) L-dimensional row vector defined f ( x) = ( f 1 ( x), , f L ( x)) ; (5)Determine the input x belongs to the first J Class. Where J = arg k min d ( f ( x), sk ), sk is k line vector of code matrix S. Hamming distance d (u , v) = {i | ui ≠ vi } [3][8].
5
Results of Diagnostic Testing of Transformers
To test the least squares support vector machine on fault diagnosis, the data of transformer failure was used to test. Large power transformers are the most important
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power system substation equipment. It is higher demands to the stability and reliability of supply. It is a major impact of the insulation of large power transformers. Meanwhile, the daily production and life of the power density, electricity consumption is increasing, the insulation of transformers and other equipment to further increase the number of shocks. Transformer as the core equipment supply system, it affects the safe operation of the power supply system. [9] Oil and oil-paper form insulation within the transformer. When there is latent inside the device overheating or failure, a variety of discharge gas will be produced. Such as H2, CH4, C2H6, C2H4, C2H2, CO and CO2. Dissolved Gas-in-oil Analysis (DGA) is Common method for transformer fault diagnosis. It is by means of dissolved gases in oil types and the corresponding relationship between the internal fault, according to the gas composition and concentration of gases inside the transformer to determine whether the abnormal. The heat and discharge within the transformer failures can be found. Electrical tests can find difficult to find with the potential failure to effectively diagnose early, and real-time. [10] Transformer failure mode is mainly mechanical, thermal and electrical 3 types, mainly the latter two. Overheating failures and high energy discharge fault are to run the main types of transformer faults. Second are over heat and high energy discharge faults, failures and damp spark discharge or partial discharge fault. According to the causes and severity of the typical faults of the transformer, it is divided into 6 species, including partial discharge, low energy discharge, high energy discharge, low temperature heat, the temperature hot. As the values of oil-filled transformer internal fault gas are CH4, C2H6, C2H4, C2H2 and CO, CO2, H2, These gases are characterized. The sum of these gases is to be the total content of hydrocarbon gas or total hydrocarbons. It is a very close relationship of characteristics of the gas component content and the fault type and fault severity. It is as reflected in the amount of the transformer anomaly [11]. In the experiment Characteristic quantity are CH4, C2H6, C2H4, C2H2, and H2. Were used 107 groups of training data, where the normal state of 31 groups, low temperature heat for the 13 groups, the temperature in heat for 18 groups, high-temperature heat for the 16 groups, partial discharge of 9 group, low energy discharge for the 7 groups, high-energy discharge is 13 group. With 73 groups of test data, by experiment, the Gaussian kernel function is selected. Results are as follows: Table 1. The diagnostic accuracy of seven state (%)
Normal state Low-temperature heat Medium temperature hot Super heater PD Low energy discharge High-energy discharge
LS-SVM
PSVC
81.82 90.00 85.71 84.62 71.43 100 100
90.91 90.00 92.86 92.31 85.71 100 91.67
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Table 2. Two support vector machine training time and testing time Training time (s) LS-SVM PSVC
0.16 1.37
Test Time (s) 1.37 0.015
From the results it is higher accuracy rate PSVC than LS-SVM on fault diagnosis. But Samples of discrete data and test data, and classification of machine noise on the training, testing will be impacted. The data will be collected to remove the noise by technical means; the training will improve the classification. Because experimental data is limited, Classifier accuracy will be affected. Confirmed by comparing the training of LS-SVM is very fast, which requires recognition speed has a great advantage in fault diagnosis.
6
Conclusions
PSVC inherited the advantages of LS-SVM; the data can reduce noise interference and eliminate multiple correlations between variables on the modeling of impact, and can effectively extract the high order nonlinear characteristics of the original input. The results show that PSVC LS-SVM and SVM have inherited a good modeling performance. Two methods not only reduce the complexity of modeling, but also to improve the generalization ability of the model. In contrast, recognition accuracy was improved PSVC than LS-SVM. Experiments also show that the two types of support vector machine are successful in transformer fault diagnosis. Acknowledgments. This project was supported by the Science Foundation of Hebei United University (qd201007) and teaching and research to guide the project (qgjg201019).
References 1. Vapnik, V.N.: Statistical learning theory. Springer, New York (1995) 2. Cortes, C., Vapnik, V.: Support vector networks. Machine Learning 20(3), 273–297 (1995) 3. Deng, n., et al.: Support vector Machine Theory, algorithms and Development, p. 176. Science Press, Beijing (2009) (in Chinese) 4. Suykens, J.A.K., Vandewalle, J.: Least Squares Support Vector Machine Classifiers. J. Neural Processing Letters, 293 (1999) 5. Osuna, E., et al.: An improved training algorithm for support vector machines. In: J. Nerual Networks for Signal Processing VII-Proceedings of the 1997 IEEE Workshop, p. 276. IEEE (1997) 6. Fung, G., Mangasarian, O.L.: Proximal support vector machine classifiers. In: Proceedings of International Conference of Knowledge Discovery and Data Mining, pp. 77–86 (2010)
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7. Platt, J.: Fast training of support Vector machines using sequential optimization. In: Dietterich, T.G. (ed.) Advances in Kernel Methods Support Vector Learning, p. 233. MIT Press (1996) 8. Dietterich, T.G., et al.: Solving multi-class learning problems via error-correcting output codes. Journal of Artificial Intelligence Research 2, 263–286 (1995) 9. Xu, J., et al.: Nonlinear process monitoring and fault diagnosis based on KPCA and MKL-SVM. Chinese Journal of Scientific Instrument (11), 2428–2433 (2010) (in Chinese) 10. Chen, W., et al.: Application of Fault Diagnosis for A Equipment Based on Binary Tree Support Vector Machines. Avionics Technology 41(2), 19–23 (2010) 11. Fang, K., et al.: Insulation fault diagnosis for traction transformer based on PSO and SVM. Computer Aided Engineering 19(3), 83–86 (2010) (in Chinese)
Application of Grey Forecasting Model to Load Forecasting of Power System Yan Yan1, Chunfeng Liu1, Bin Qu2, Quanming Zhao2, and Feifei Ji3 1
College of Sciences, Hebei United University College of Electric and Engineering, Hebei United University 3 College of Mining Engineering, Hebei United University, Tangshan, Hebei, China {Yan Yan,yanjxky}@126.com 2
Abstract. The grey GM (1, 1) model is a kind of more effective load forecasting model, however, because power load has diversity, causing some variation is larger, the load forecasting error cannot match the requirements. Precision in practical application has certain limitations. The grey GM (1, 1) model use the necessary improvements model ,such as equal dimension new information recurrence model and subsection of GM (1, 1) load forecasting model, through analysis shows that can increase the prediction precision. Keywords: Power systems, load forecasting, grey system, GM (1, 1) model, equal dimension new information recurrence model, segmentation.
idea and analysis method of energy management .With neural networks and fuzzy mathematics, genetic calculate hair, rough sets theory, support vector machines, the development and application of grey theory, expert system theory, the fuzzy mathematics, etc, as a representative of the emerging interdisciplinary theory has made the development of electric power system with former sex more opportunities. Under the market economy condition, the power system of load forecasting accuracy will directly affect the quality and the efficiency of economic operation. In short, do well the power system load forecasting; has a lot of great economic benefits and social benefits.[1]
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The Contents of Power Load Forecasting
Power load forecasting is meritorious load, including the largest reactive load, load power and load curve prediction. The size of the largest active load is to determine the scale of the installed power system based data, the district distribution characteristics meritorious load transformation planning and distribution planning is the main basis. The size of the reactive load is to determine the power system of reactive power planning, is fundamental to affect the safety of the electricity system of economic operation of the important factors. In order to select the appropriate unit types and reasonable power structure and determine the fuel plan etc, must predict load power. Load curve prediction in electric power planning and power system operation, is sure is vital in the power system, the power structure, lowering capacity demand, operation mode and energy balance the main basis for the study of power system, the peak problems, pumped storage power plant capacity, and to send transmission equipment coordinated operation provide data support. The load forecast according to objective different cent is super short term, shortterm, medium-term and long-term. Short-term load forecasting used to arrange day scheduling plan and weekly scheduling plan, including determine unit starting and stopping, fire and water electricity coordination, non exchange power, the economic load distribution, reservoir scheduling and equipment maintenance etc, medium-term load forecasting is determining the unit operation and equipment overhaul plan etc. Long term load forecasting is mainly power grid planning departments according to the development of national economy and the demand for power load of network reconstruction and expansion work long-term planning. For the long-term forecast, to a special study of national economic development, the influence of national policies, etc. The load forecast lies in collecting a large amount of historical data, establish scientific and effective prediction model, adopt effective algorithm, based on historical data, lots of experimental research, summarizing the experience, and constantly correction model and algorithm to reflect genuine load change rule.[2] 2.1
Historical Load Material Selection and Collection
Historical load material is predicted the fundamental basis for the data that occupies the credibility of the abundant degree and the data to predict the results are very important. Investigation and collection of material, including various electric power enterprise internal material and external material, the national economy of the
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relevant departments of the material, as well as publicly published and unpublished published material, from numerous material choose in a fraction of a useful, namely material enrichment to minimum. Select material standard, a direct about sex, want reliability,and the latest sex. If data collection and choose well, it will directly affect the quality of the load forecast. 2.2
Footnotes
Because the quality does not exceed the forecast for the quality of used data collected, the relevant statistics with load review and processing collate, laying the foundation for guarantee the quality prediction. Both must note material intact, digital accurate, reflect normal level, material without exception "separate item", but also pay attention to the calculation, vacancy information to verify the information not reliable adjustment. The analysis of data uses material data analysis of historical data preprocessing, namely the abnormal values of the smooth and missing data for addenda, mainly by abnormal data processing, vertical treatment level. Data in the level of analysis data processing namely when the two time before, will load data set as the benchmark, the biggest change data to be processed, when processed data range beyond this just as bad data, using the average method of vertical change data smooth handle the data preprocessing in namely load when considering the small cycle that different date the same point in the load should be similar to the load value with time, should be maintained in a certain range, the bad data beyond the scope for correction. 2.3
Load Prediction Model
Load forecasting model is statistical data, prediction model track generalizations are diverse, for specific material must choose appropriate forecast model, is the load forecasting process important step. When the model prediction error caused by improper selection is too high, will need to change model, or use both calculations, several mathematic models to contrast, choice. In choosing the right after forecasting technology, establish the load forecast mathematical model, forecasting work. To affect the new forecasted object analyzes the factors of prediction model, carries on the appropriate correction determined after predictive value.
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The Grey System Theory
Gray system has three basic features: the first is integrative, integrated principle is system analysis according to and starting point. The second is to optimize its analysis, optimization principle is the basic purpose. The third is modeling, modeling principles is the means and the necessary as optimization approach. The gray system content mainly includes gray hazy based theory system, sets by the grey relation analysis system based on space, with gray process and to generate space for basic and connotation, the method system with grey model (GM) as the core of the model system, system analysis, evaluation, modeling, forecasting, decisionmaking, control and optimization as the main body of the technical system, and launched a gray mathematics research. Which includes six aspects, including: the
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content of the theory of grey system modeling, gray system control theory, the grey relational analysis method, grey forecasting methods, gray planning method, gray decision-making method, etc. Grey forecasting is the main behavior and correlation factor system together with more than forecast, namely the sequence in analysis and research system factors influence each other and coordination function, establishing the system based on the main behavior characteristic of grey correlation factor of the dynamic model, and through solving the forecast. The basic requirement of system prediction is that through the establishment of GM model, research and prediction system dynamic change, to master its development regularity, control the coordination change direction and speed, making toward people's desire goal development. Forecast by The basic mathematical method with state equation is established and abnormal points forecasts. Gray sequence forecast is refers to the use of dynamic GM model, the system time's series forecast, namely the quantity size of system main behavior characteristic or some indexes, development and change to the future particular moment of numerical prediction appeared. Gray decision based on grey target as a target, measured by credibility on grey target the size of the true extent of information. Grey target is a regional or limits, namely grey target set. Gray planning mainly is the study of the existing conditions in a given, how to use resources to maximize benefits. GM model of grey model is grey model. Generally speaking, modeling uses original data to establish difference equations. The gray system modeling uses primitive data to establish a set of differential equations. Because the system is polluted by the noises, so the original data show discrete, the dispersive sequence is also a pessimistic sequence, or the gray process model,become gray model. The gray system theory can set its a of differential equations, which is based on the model of the concept, views and methods [3][4] 1. The gray theory will random variables as a certain range gray variables, which stochastic process as in certain scope, certain areas of gray process changes. 2. After the gray theory will generate erratic originally data, making it into a regular generation series, so GM model again modeling is actually generate sequence model. 3. Gray theory open bite topology defines the time sequence, and defines information measure of concentration, also defines the ash derivative and gray differential equation. 4. The grey theory through the different ways of generation mode, data for residual choices and different GM model to adjust and amend, improve precision. 5. The gray system theory model bases on the concept of correlation degree and convergence theory. 6. Gray GM model general use three tests, namely the residual error test. Residual error test accord to point inspection, relational coefficient test is a kind of test to establish model and the designated function of inspection, approximate sex between poor inspections is effective after the residual distribution random properties testing. 7. For high-order system modeling, gray theory is through the GM (1, N) model of solution. 8. GM model data which must be reduced by inverse generation can use it.
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The Gray System Model
A model of a system, is refers to various factors in the system, the relationship between among various factors a system integrity, relevance, causality materialization. As the mathematic model of the system, it is the nature of the quantification. And gray theory research model of the system, in addition to the nature of the general quantity relationship, especially attention outside the development and change of the relationship between factors, including dynamic relations. The gray system modeling will Must be combined with qualitative and quantitative to qualitative as the forerunner, take the quantitative as the means and the backing, must go through thought development, factor analysis, factors causal relationship between the causal relationship between the quantification, factors such as dynamic, system optimization five steps. [5] 4.1
The Gray System GM(1,1) Forecast Model
The differential equations established by the gray system reveal that the power load varies continuously with the time. At the first of all, the GM(1,1) model makes a first(0) (0) order accumulation production for historical series x = [ x (k ) k = 1, 2," , n] , which (1) (1) can get the accumulation production series x = [ x (k ) k = 1, 2," , n] that is more regular. Then the GM(1,1) model establishes the first-order differential equations for production series, which can make the power system load forecasting after getting the function expression. The GM(1,1) model’s expression is the first-order differential equations dx (1) / dt + ax (1) = u obtaining x (1) predictive results: x (1) (k + 1) = [ x (0) (1) − u / a ]e − ak + u / a , k = 0,1, 2,"
The grey forecasting model of historical series x (1) is x (1) (k + 1) = (e − a − 1)[ x (0) (1) − u / a ]e − ak , k = 0,1, 2," where a is the grey coefficient, and u is the given constant.[6] The ordinary gray GM(1,1) model has certain limitations when we apply it to the load forecasting. It only applies that the awaiting prediction quantity has the constant growth rate or the short, mid load forecast increasing by index, and has the larger errors for E, S curve, and the curve which is no obviously changing as well as the long-term load forecasting. Therefore, we need to improve the ordinary gray GM(1,1) model. 4.2
The Improved Gray System GM (1,1) Forecast Model
The ordinary gray GM(1,1)model has the larger predictive deviation when it predicts long-term data and waving larger data. The main reason is that we treat parameters as constants, do not introduce new information model, and have old information be not removed. Based on this, we have established and developed equal dimension
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information recursive grey GM(1,1)model.The model treats parameters as function of time t. Firstly, it predicts the two parameters, then it uses the grey forecasting methods to predict original data. The basic methods are as follows: Follow the parameters a (k ) and u (k ) , establish parameters’ sequences of the estimation of the number {a(k ), u (k )} , and through analysis and finding out the laws a (k ) and u (k ) we predict the next step parameters a (k + 1) and u (k + 1) . Parameters tracking formula is as follows:[7] a (k ) = a(k − 1) + u (k ) = u (k − 1) +
δ 2 k −1
a
+ β k2−1
δ ak2−1 + β k2−1
ak −1ψ (k )
β k −1ψ (k )
ψ (k ) = x (1) (k ) − [ x (1) (k ) − x (k − 1)] (1)
ak −1 = − ak −1[ x(0) −
u (k − 1) − ak −1 ( k −1) ]e , β k −1 = −e − ak −1 ( k −1) + 1 a(k − 1)
, δ is constant.
In the equal dimension information recursive model, firstly we use the GM (1, 1) model to predict a figure. Next we will supplement the predictive figure behind the known data, remove the oldest data in order to keep the series equal dimension at the same time, then build up the GM (1, 1) mode to predict the next data, Again and again. The technology of the metabolism is applied in the model, and the dual roles of the Parameter prediction and the metabolism will make the gray GM (1,1) model greatly improved in forecasting accuracy.[12] 4.3
The Segmented Gray Revise Model
We usually meet the following issues when we apply the GM (1, 1) model. Firstly, because GM (1, 1) model describes the model of things which varies as the laws of index, and the actual system can not vary as the changing laws of the strict index, so it will cause the greater errors. [8] Secondly, the development of the actual system is restricted by various factors, could not last development at a speed, usually presenting the fast or slow trend that goes forward in the type of the wave .and using the GM (1, 1) model is hard to get the desired results. Thirdly, the GM (1, 1) model is x exponential function model y = be and with x increasing value y will be also growing rapidly, causing prediction accuracy is very low. In view of the above problems, according the growth of the power load has a periodic index performance and the characteristics that different phases have different growth rate. We improve the GM (1, 1) model and put forward the GM (1, 1) modeling method. As for a time series we make the scatter diagram which is divided into several stages according to the development trend, and every stage can obviously take on the concave or convex drab change, then for every stage series we use the
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grey forecasting methods to respectively establish corresponding GM (1, 1) model. Because the power load change periodically and with the years, months, weeks, days, periods and so on it presents periodic fluctuation. Different periods has different a (k ) and u (k ) , but during the same periods a (k ) and u ( k ) are very close. The power load belong to the nonstationary random process, and with the years, months, weeks, days, periods and so on it presents a certain Periodicity .Directly using the GM (1, 1) grey model actually only considers the load’s changing trend.[11] However, it is not very sensitive to the periodic term and the stochastic volatility term in the load forecast, especially when the discreteness of the power load is larger, its predictive errors is large, difficultly passing the hypotheses test. Therefore, before the prediction we use a certain mathematical method to have the power load decomposed into tendency item, periodic variables and random variables, then according to the characteristics of the different variables we respectively choose appropriate predictive model, carry out timing Extrapolation and stack Extrapolation results in order to achieve the purpose of forecasting. Generally, the nonstationary power load X (t ) signified by formula is as follows: L(t ) = X (t ) + Z (t ) + V (t ) in formula, L(t ) is the power load at t o'clock, X (t ) is tendency item, Z (t ) is periodic item, V (t ) is the stochastic volatility term, t is time. For the original series X 0 ( x0 (1), x0 (2)," , x0 ( n)) the GM (1, 1) model established can filter out tendency item X (t ) , namely:[9] u x 0 (t + 1) = (1 − eα )( x0 (1) − )e−α t .
α
t = 0,1, 2," , n − 1 , we can obtain the Fitted Values sequence {x 0 (i ) i = 1, 2," , n} of tendency item. After determining the partial tendency item X (t ) , we try to eliminate item X (t ) in order to obtain a new Sequence that contains the sum of periodic item and random item. Namely, what is the new data series which consists of deviation of the original sequence’ each load value relative tendency item, noted for Z (t ) = X (t ) − l X 0 (t ) . The 1
0
periodic changes of the daily load mainly reflects on the periodic alteration in every 24 hours intervals, thus eliminating periodic item and acquiring random residual sequence further, notes for V (t ) = Z1 (t ) − Z1 (t − 24) .[10] In the power system load affected by a variety of factors, its appearance is the random fluctuation of power load. Thus power load is a random variable, due to the interference and during the different periods interference is always uncorrelated, From quite a long time period, the total average value of interference is zero .Therefore, in the power load forecasting, the left residual is a normal, stable and random process after filtering out tendency item, which can be simulated and predicted by Time Series Method .By using model identification we can adopt the autoregressive AR (2) model. [13][14]
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References 1. Zhang, D., Shi, K., Jiang, S.: Parameter amendment method in grey load forecasting. In: Proceedings of the EPSA, vol. 13(2), pp. 20–22 (2001) 2. Wei, L., Li, H.: Application of Combination Grey Model in Power Load Forecasting. Journal of Chongqing University(Natural Science Edition) 27(1), 36–39 (2004) 3. Peng, X., Cheng, S., Chen, D.: Method of Short Term Load Forecasting Based on Segmentation Grey Model. Journal of Huazhong University of Science and Technology 23(1), 138 (1995); Conference on Computer & Industrial Engineering, Limerick, Ireland, vol. 3(1), 526–531141 (2003) 4. Liu, S.: Emergence and Development and Forward Trends of Grey Systems Theory. In: Proceedings of the 32nd International Conference 5. Ji, P., Zhou, H., Zhang, Y.: Application of Unibased Grey Forecasting Model to Load Forecasting of Power System. Journal of Three Gorges University (Natural Science Edition) (08) (2005) 6. Li, Y.: The Application of Improved Grey Model in Power System Load Forecast. Power System and Clean Energy (03) (2009) 7. Zhao, Z., Wan, J.: Method of Load Forecasting Based on Segmentation Grey Model. Electric Power Automation Equipment (2002) 8. Cui, W., Cheng, X., Shi, D.: Application of gray system theory in load forecasting. Electric Power Automation Equipment (2004) 9. Li, Q.-d., Chi, Z.-x., Wang, D.-g.: Load forecasting model based on data mining technique. Journal of Dalian University of Technology (06) (2003) 10. Chen, Y., Ma, L., Mu, G., Zhang, X., Fan, G.: Comparison Studies on Two Types of Accuracy Criteria For ShortTerm Load Forecast. Automation of Electric Power Systems (17) (2003) 11. Zhang, M., Cui, W.: Prediction of load based on grey theory and BP networks. Journal of Liaoning Technical University, Natural Science (2011) 12. Han, H., Li, L.: The Gray Remaining Modified Model’s Application to Mid-long Term Load Forecasting. Science & Technology Information (07) (2010) 13. Zhang, J., Qiu, W., Liu, N., Zhang, X.: Grey Model Based on Orthogonal Design and Its Application in Annual Load Forecasting. Power System and Clean Energy (02) (2010) 14. Ai, J., Du, X., Huang, L.: Application Analysis of Several Load Forecast Methods in Tibet Power Grid. Hubei Electric Power (05) (2010)
The Model of NW Multilayer Feedforward Small-World Artificial Neural Networks and It’s Applied Ruicheng Zhang and Peipei Wang College of Electrical Engineering, Hebei United University, Hebei Tangshan 063009, China [email protected]
Abstract. To find the optimal neural network structure , the structure of multilayer forward neural networks model is studied based on the research methods from the complex network, a new neural networks model, NW multilayer forward small world artificial neural networks can be proposed, whose structure of layer is between the regular model and the stochastic model. At first, regular of the multilayer feed-forward neural network neurons randomized cross-layer link back layer with a probability p to construct the new neural networks model. Secondly, the cross-layer small world artificial neural networks are used for function approximation under different re-wiring probability. The counts of convergence under different probability are compared by setting a same precision. Simulation shows that the small-world neural network has a better convergence speed than regular network and random network nearly p=0.08, the optimum performance of the NW multilayer forward small world artificial neural networks is proved in the right side of probability increases. Keywords: NW small-world networks, multilayer forward neural networks, function approximation.
Hopfield associative memory model the small-world architecture turned out to be optimal in terms of memory storage abilities. With an integrate-and-fire type of neuron it has been shown that short-cuts permit self-sustained activity. A model of neurons connected in small-world topology has been used to explain short bursts and seizure-like electrical activity in epilepsy. In biological context some experimental works seem to have found scale-free and small-world topology in living animals like in the macaque visual cortex, in the cat cortex and even in networks of correlated human brain activity measured via functional magnetic resonance imaging. The network of cortical neurons in the brain has sparse long ranged connectivity, which may offer some advantages of small world connectivity. The traditional multi-layer neural network can be considered as regular network. So we evolve it into small world neural network, a new neural networks model, NW multi-layer forward small world artificial neural networks can be proposed, whose structure of layer is between the regular model and the stochastic model. At first, regular of the multilayer feedforward neural network neurons randomized cross-layer link back layer with a probability p to construct the new neural network model. Secondly, the cross-layer small world artificial neural networks are used for function approximation under different re-wiring probability. The counts of convergence under different probability are compared by setting a same precision. Simulation shows that the small-world neural network has a better convergence speed than regular network and random network nearly p=0.08, the optimum performance of the NW multi-layer forward small world artificial neural network is proved in the right side of probability increases.
2
The Model of NW Small-World Networks
Previous studies have concentrated on the one-dimensional version of the small-world model. In one dimension the model is defined on a lattice with L sites and periodic boundary conditions (the lattice is a ring). Initially each site is connected to all of its neighbors up to some fixed range k to make a network with coordination number z=2k. Randomness is then introduced by independently rewiring each of the kL connections with probability p. ‘Rewiring’ in this context means moving one end of the connection to a new, randomly chosen site. The behavior of the network thus depends on three independent parameters: L, k and p. NW small-world networks will study a slight variation on the model in which shortcuts are added between randomly chosen pairs of sites, but no connections are removed from the regular lattice. For large L, this makes no difference to the mean separation between vertices of the 2 k −1
. At order p2k and higher it does make a difference, since network up to order p the original small-world model (WS) is poorly defined in this case – there is a finite probability of a part of the lattice becoming disconnected from the rest and therefore making an infinite contribution to the average distance between vertices, and this makes the distance averaged over all networks also infinite. The variation of NW small-world networks does not suffer from this problem and this makes the analysis significantly simpler. In Fig. 1 we show some examples of small-world networks.
The Model of NW Multilayer Feedforward Small-World Artificial
p=0
0
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Fig. 1. Rewiring of a regular lattice. From left to right: regular lattice; graph after only a few edge rewiring; regular network and random network overlay.
Based on the topology of the NW small-world networks, the model of NW multilayer feedforward small-world artificial neural networks is proposed. The model generation process is as follows. (1) Initially, neurons are connected feedforward, i.e. each neuron of a given layer connects to all neurons of the subsequent layer. (2) We make a random draw of two nodes which are connected to each other. We don’t cut that “old” link. In order to create a “new” link, we make another random draw of two nodes. If those nodes are already connected to each other, we make further draw until we find two unconnected nodes. Then we create a “new” link between those nodes. (3) In this way we create some connections between nodes in distant layers, i.e. short-cuts and the topology changes gradually (see Fig.[2]). 3.2
The Flow of the Algorithm
The NW small-world artificial neural network is a multilayered, feedforward neural network and is by far the most extensively used. Back Propagation works by approximating the non-linear relationship between the input and the output by adjusting the weight values internally. A supervised learning algorithm of back propagation is utilized to establish the neural network modeling. A normal NW smallworld artificial neural networks model consists of an input layer, one or more hidden layers, and output layer. The input samples are X = [ X 1 , X 2 , , X k , X N ] , the
X k = [ x k 1 , x k 2 , x kl ] , the actual output of the network is Yk = [ y k 1 , y k 2 , y ko ] , Expected output is d k = [d k 1 , d k 2 , d ko ] . So the NW
any input sample is
small-world artificial neural networks program-training process as follows.
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(a) p=0
(b) p=0.05
(c) p=1 Fig. 2. Scheme of network connection topologies obtained by randomly cutting and rewiring connections, starting from regular net (a) and going to random net (c). The small-world network is located somewhere in between.
Step 1: Design the structure of neural network and input parameters of the network. Step2: Get initial weights W and initial threshold values from randomizing. Step 3: Input training data matrix X and output matrix dk. Step 4: Compute the output vector of each neural units. (a) Compute the input and output vector of the No.1 hidden layer I
u mM11 = wim1 x ki
(1)
i =1
I
vmM11 = f ( wim1 xki ) i =1
;
m1 = 1,2, , M
Compute the input and output vector of the No. s hidden layer
(2)
The Model of NW Multilayer Feedforward Small-World Artificial s −1 M t
I
u
Ms ms
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= wims x ki + wmt m s u mMt t i =1
(3)
t =1 mt =1
v mMss = f (u mMss ); M s = 1,2, , M
(4)
(b) Compute the output vector of the output layer I
Mt
s
uoM o = wio xki + wmto umMt t
(5)
y ko = f (uoM o ) o = 1,2, O ;
(6)
i =1
t =1 mt =1
(c) Compute the error signal of the Output layer neurons
1 O [d ko (n) − yko (n)]2 2 o =1
E=
Step 5: Compute the local gradient (a) Compute the local gradient of the output layer
(7)
Mo
δ oM (n ) = [(1 − y ko (n ))]2 (d ko (n ) − y ko (n )) o
(8)
o = 1,2, , O (b) Compute the local gradient of the last one hidden layer O
δ mM (n) = vmM (n)(1− vmM (n))δoM (n)wms (n) s
s
s
s
s
o
o
s
(9)
o=1
m s = 1,2, , M S (c) Compute the local gradient of the hidden layer S
ms
Mt
δ (n) = v (n)(1− v (n))[ δmM (n)wm m (n) Ms ms
Ms ms
Ms ms
t
t = s+1 mt =1
S
t
s t
(10)
Mt
δ (n) = v (n)(1− v (n))[ δmM (n)wm m (n) Ms ms
Ms ms
Ms ms
t
t = s+1 mt =1
O
+ δ o=1
MO o
ms =1,2,, Ms
(n)wmS o (n)]
t
s t
(11)
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Step 6: Renew W
Δw Sji = w Sji (n − 1) + ηδ jS yiS −1 (n − 1)
(12)
Δb Sji = αb Sji (n − 1) + ηδ jS y iS −1 (n − 1)
(13)
Step 7: Repeat step 3 to step 6 until converge.
4
Simulation and Discussion
Nonlinear function approximation is a typical application of neural networks. The following non-linear function is used as the test function of the NW small-world artificial neural networks. The non-linear function has multiple local minimum. In order to have good approximation results, the network must have a better ability to jump out of local minimum.
y ( x) = 0.1 × sin(5πx) + 0.3 × sin(10πx) + 0.4 sin(8πx) , x ∈ (0,1)
(14)
In tests, an input data corresponding to a desired output, the networks have 5 hidden layers, 5 neurons of each hidden layer, the network input layer and output layer neuron number is 1, Hidden layer neuron number is 5. We take 18 reconnection probability values between 0 and 1. The program runs 100 times independently to each reconnection probability value. The program runs 10,000 times as the algorithm termination condition. The inertia factor α = 0.9 , learning rate η = 0.05 , these sampling points were divided into 50 samples as input, the initial connection weights are a random number between 0 and 1. The network structure was used as shown in Figure 2. When p = 0.08, the approximation result of the nonlinear function is shown in Figure 3. From the average of the objective function approximation curve, we can see better approximation.
Fig. 3. The approximation curve when p=0.08
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In addition, suppose ε <0.0001, in order to study the convergence of the network, when the program runs 100 times independently to each reconnection probability value, the average iterations number is shown in Figure 4. The abscissa is the random probability p, y-axis is the times of iterations. When p=0.08, the Convergence rate is fastest. In Table 1, N s denotes the times of converge to set the number of precision.
N a denotes the average iteration number of successfully converge to set the precision. Simulation shows that the small-world neural network has a better convergence speed than regular network and random network nearly p=0.08, the optimum performance of the NW multi-layer forward small world artificial neural network is proved in the right side of probability increases.
Fig. 4. The average number of iterations with different probability Table 1. Statistical results of the convergence under the set accuracy
5
Conclusions
It is difficult to design the topology of the neural networks. Over the past, the topologies of most of the neural network model were approximate rule network. In this paper, a new neural networks model, NW multi-layer forward small world artificial neural networks can be proposed, whose structure of layer is between the regular model and the stochastic model. At first, regular of the multilayer feed-forward neural network
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neurons randomized cross-layer link back layer with a probability p, constructs the new neural network model. Secondly, the cross-layer small world artificial neural networks are used for function approximation under different re-wiring probability. The count of convergence under different probability are compared by setting a same precision, simulation shows that the small-world neural network has a better convergence speed than regular network and random network nearly p=0.08, the optimum performance of the NW multi-layer forward small world artificial neural network is proved in the right side of probability increases. Acknowledgments. This work was supported by the National Natural Science Foundation of China (grant number: 61040012).
References 1. Xia, Y.S., Wang, J.: A general methodology for designing globally convergent optimization neural networks. IEEE Transactions on Neural Networks 9(6), 1331–1343 (1998) 2. Liu, O., Li, S., Xiao, Q.: Research on A Structure of Multi-Layer Forward Artificial Neural Network. Jour. Nat. Scie. Human Norm. Univ. 27(1), 26–30 (2004) 3. Zhang, M., Yu, Y., Hu, X., et al.: Study Oil Social Network’s Modeling of Virtual Social Simulation. Computer Simulation 26(2), 14–17 (2009) 4. Situ, J.: The small world network of Internet. Journal of Information 12, 86–88 (2004) 5. Wang, B., Wang, W., Yang, X., et al.: Research of modeling and simulation on WS and NW small-world network model. Journal of Zhejiang University of Technology 37(2), 179–182 (2009) 6. Watts, D.J., Strogatz, S.H.: Collective dynamics of small world networks. Nature 393, 440–442 (1998) 7. Newman, M.E.J., Watts, D.J.: Renormalization Group Analysis of the Small-world Network Model Physics Letters A 263(4), 341–346 (1999) 8. Simard, D., Nadeau, L., Kroger, H.: Faster learning in small-world neural networks. Physics Letters A 336(1), 8–15 (2005) 9. Li, X., Du, H., Zhang, J., et al.: Multilayer feed forward small-world neural networks and its function approximation. Control Theory & Applications 27(7), 836–842 (2010) 10. Wang, X., Li, X., Chen, G.: Complex network theory and its applications. Tsinghua University Press, Beijing (2006) 11. Yang, M., Xue, H., Analysis Of, G.: Knowledge Communication Network Based on Complex Network. Computer Simulation 26(11), 122–123 (2009)
Harmony Search Algorithm for Partner Selection in Virtual Enterprise Zhan-fang Zhao, Li-xiao Ma, Wen-long Qu, Ji-wei Xu, and Ji-chao Hu Department of Computer Science, Shijiazhuang University of Economics, Shijiazhuang, 050031 [email protected]
Abstract. Partner selection and optimization is one of key factors in building virtual enterprise, which have impact on the success of virtual enterprise. This paper analyzed the process of selecting partners and established the optimization model for partner selection. This paper applied harmony search (HS) algorithm into the optimization model, the results show that the HS algorithm has better performance than genetic algorithm. Also, sensitivity analysis of HS parameters was performed to obtain a better idea of algorithm parameter values. Keywords: Harmony search algorithm, Meta-heuristic algorithm, Virtual enterprise, Partner selection.
Therefore, it is very necessary to seek highly efficient optimization algorithm. Right now, some meta-heuristic algorithms have been applied to partner selection and optimization. They mainly include genetic algorithm[1][2][3] and ant colony algorithm[4][5]. The shortcoming of these algorithms is that it is not efficient or even creates wrongful solution when there are too many subtasks, candidate resources and restriction. This paper will introduce a harmony search (HS) algorithm[6] to solve the partner selection problem. The HS algorithm is a new technique in the field of optimization and it is a powerful and general global optimization method, which has been successfully applied to various real-world optimization problems[7]-[14]. This paper apply HS algorithm into the optimization model of partner selection. The results indicate that this algorithm has better performance in comparison with genetic algorithm. The rest of paper is organized as follows. In Section 2 we discuss the optimization model for partner selection. In Section 3 we explain the fundamentals of HS algorithm. In Section 4 we apply HS algorithm into the partner selection, also, sensitivity analysis of HS parameters was performed. Finally, Section 5 makes a conclusion.
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Mathematical Model of Partner Selection
In the process of building the VE, partner selection can be described as: the manufacturing task is divided into n subtasks in a certain order. To let preorder set is H . Subtask i has mi bidding enterprises; however, only one enterprise can be chosen. Bidding enterprise needs to pay a manufacturing cost for the subtask it bids on. If (i, j ) ∈ H , subtask i is the direct preorder of subtask j . There is also a material transportation cost between subtask i’s enterprise and subtask j’s enterprise. The goal of optimization is to choose the best enterprise from all bidding enterprises for each subtask and therefore obtain lowest total product manufacturing cost (production cost and transportation cost). The meanings of symbols are as below:
T = {1,2,..., n} :number set of subtask;
Ri = {ri1 , ri 2 ,..., rim } :number set of bidding enterprises for subtask i (i = 1,2,..., n ) ;
H = {(i, j ) | i ∈ T ∧ j ∈ T ∧ i ≠ j ∧ subtask i is the direct preorder of subtask j Manufacturing cost of bidding enterprise rik 1 ≤ i ≤ n,1 ≤ j ≤ mi ) ;
C rik
（
：
W rik r jh
（
：
The
material
transportation
cost
r jh 1 ≤ i , j ≤ n ,1 ≤ k ≤ m ,1 ≤ h ≤ m ) if (i, j ) ∉ H , , xrik
：r
from
rik
}; to
W rik r jh = 0 ;
ik be chosen or not. The mathematical model of partner selection is:
n
mi
n
mi
n
mj
min cos t = x rik c rik + x rik x r jh W rik r jh i =1 k =1
mi
i =1 k =1 j =1 h =1
，
st . x rik = 1 (i = 1, 2 ,..., n ) k =1
(1) . (2)
.
Harmony Search Algorithm for Partner Selection in Virtual Enterprise x rik =
3
， ，
1 rik is chosen
(i = 1, 2,..., n ;
0 rik is not chosen
k = 1, 2 ,..., m i )
.
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(3)
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Recently, Geem developed a new harmony search (HS) meta-heuristic algorithm[6] that mimics the musical improvisation. The steps in the procedure of HS are described in the next five subsections. 3.1
Initialize the Problem and Algorithm Parameters
First, the optimization problem is specified as follows: Minimize
Subject to xi ∈ X i ，i = 1,2,..., N .
f (x)
(4)
Where f (x) is an objective function; x is the set of each decision variable x i ; X i is the set of possible range of values for each decision variable, that is for discrete decision variables, X i = {x i (1), x i (2 ),..., x i (k )} X i = {x i (1) < x i (2 ) < ... < x i (k )} or
L
xi ≤ X i ≤ U xi for continuous decision variables;
N is the number of decision variables; and K is the number of possible values for the discrete variables. The HS algorithm parameters are also specified in this step: harmony memory size (HMS), harmony memory considering rate (HMCR), pitch adjusting rate (PAR), and termination criterion (maximum number of searches). 3.2
Initialize the Harmony Memory
In Step 2, the HM matrix is filled with as many randomly generated solution vectors as the HMS. The harmony memory (HM) is a memory location where all the solution vectors (sets of decision variables) are stored. x11 2 x1 HM = x HMS −1 1 x1HMS
3.3
x 12 x
2 2
...
x 1N −1
...
x
2 N −1
x 2HMS −1 ...
−1 x NHMS −1
x 2HMS
x NHMS −1
...
x HMS −1 xN x NHMS
x 1N
2 N
.
(5)
Improvise a New Harmony
A new harmony vector, x ' = {x1' , x 2' ,..., x N' } is generated from the HM based on memory considerations, pitch adjustments, and randomization. For instance, the value of the first decision variable (x1' ) for the new vector can be chosen from any value in
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the specified HM range (x11 ~ x 1HMS ) . Values of the other decision variables (x i' ) can be chosen in the same manner. Here, there is a possibility that the new value can be chosen using the HMCR parameter, which varies between 0 and 1 as follows:
{
x i1 ∈ x i1 , x i2 ,... , x iHMS x i' ← ' x i ∈ X i
}
w . p . HMCR w . p . (1 − HMCR
)
.
(6)
The HMCR sets the rate of choosing one value from the historic values stored in the HM, and (1-HMCR) sets the rate of randomly choosing one value from the possible range of values. Every component obtained by the memory consideration is examined to determine whether it should be pitch-adjusted. This operation uses the PAR parameter, which is the rate of pitch adjustment as follows: YES x i' ← NO
w . p . PAR w . p . (1 − PAR
)
.
(7)
If the pitch adjustment decision for (x i ) is Yes, (x i ) is assumed to be x i (k ) , it is the ' kth element in X i , (x i ) is replaced as follows: for discrete decision variables. x i' ← x i' (k + m ) (8) '
xi' ← xi' + α
'
for continuous decision variables.
Where m is the neighboring index, m ∈ (..., − 2 , − 1, 1, 2 ,... ) ; α is the value of bw × u (− 1,1) , bw is an arbitrary distance bandwidth for the continuous variable; and u (− 1,1 ) is a uniform distribution between -1 and 1. 3.4
Update Harmony Memory
In Step 4, if the new harmony vector is better than the worst harmony in the HM, judged in terms of the objective function value, the new harmony is included in the HM and the existing worst harmony is excluded from the HM. 3.5
Check Stopping Criterion
The computations are terminated when the termination criterion is satisfied. If not, Steps 3 and 4 are repeated.
4
The Application of the Harmony Search Algorithm in Partner Selection
4.1
Real Example
Let us take one example: one manufacturing enterprise has a big order and needs to finish it by creating enterprises alliance. Based on real situation, this enterprise divided this task into 7 subtasks and has chosen resource candidates for each subtask through network bid invitation, bidding and election by experts. Figure 1 is the task decomposition figure of this example. Its preorder set is H = {(1,4), (2,3), (3,5), (4,5), (5,6), (6,7 )} .
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Fig. 1. Task decomposition and resource candidates
Table 1 describes the manufacturing costs of each bidding resource for its corresponding subtask. Tables 2 describe the transportation costs between subtask bidding resources with preorder relationships. Now we need to select the optimal resource combination to meet the goal of lowest total manufacturing cost. Table 1. Manufacturing cost of bidding resources (unit: ten thousands) Resource No Manufacturing Cost
In this paper the operating environment is Windows XP operating system, Intel P4 Dual Core CPU with 2GB of RAM, 3GHz. The development environment is Visual C++ 6. We applied the HS algorithm into partner selection problem, the selection of related solution parameters of HS algorithm is an important step since these values directly influence the convergence behavior. Therefore, a sensitivity analysis was conducted to determine the best HS solution parameters. The following parameter values were used for the optimization: HMS =10;HMCR = {0 . 75 , 0 . 85 , 0 . 95 } ; PAR= {0 . 5 , 0 . 3 , 0 . 1} ; number of decision variables = 7; We performed 50 independent runs for each scheme, Iterations is the average generations of obtaining the optimal solution. Table 3 describes the results of sensitivity analysis with HS parameters.
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Table 3. Results of Sensitivity Analysis with HS Parameters Scenario
HMS
HMCR
PAR
Iterations
1 2
10 10
0.95 0.95
0.5 0.3
1202 414
3 4
10 10
0.95 0.85
0.1 0.5
204 1238
5 6
10 10
0.85 0.85
0.3 0.1
260 149
7
10
0.75
0.5
1477
8 9
10 10
0.75 0.75
0.3 0.1
416 191
All scenarios can obtain optimal partner selection (r14 , r21 , r31 , r41 , r53 , r61 , r73 ) , the global optimal value is 65.5(unit: ten thousands). Scenario 6 is the best HS solution parameters, HMCR=0.85, PAR=0.1, the convergence speed is best than other scenarios. According to the results of the sensitivity analysis, PAR parameter can affect convergence speed, when the PAR parameter is larger, the speed is lower. Figure 2 is the optimal partner selection.
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Fig. 2. Optimal partner selection
4.3
Comparison Analysis
Genetic algorithm (GA) has be applied to the partner selection in virtual enterprise. In this paper, we apply the GA[1] to solve the case. The GA parameter values: the size of population is set PopulationSize=10, crossover rate Pc=0.7, mutation rate Pm=0.2, we performed 50 independent runs for the GA, the GA could reach the global optimum 33 times out of 50 runs, the average Iterations of reaching the optimum are about 4040. The results showed that the HS algorithm display better performance than the GA in the solution precision and the convergence speed. The main differences between HS and GA are summarized as: HS generates a new design considering all existing designs, whereas GA generates a new design from a couple of chosen parents; HS takes into account each design variable independently. On the other hand, GA considers design variables dependently with building block theory. The building block theory works well only when adjacent variables in a chromosome are strongly correlated. So, the HS algorithm provides more powerful approach than GA.
5
Conclusion
In this study, a recently-developed nature-inspired algorithm, HS, has been introduced and applied to the partner selection problem in virtual enterprise. The convergence capability results revealed that the HS algorithm outperformed the genetic algorithm. The results showed that the HS algorithm is potentially a powerful search and optimization technique in terms of best solutions and convergence history. For future research, the HS algorithm should be utilized more efficiently and effectively. Acknowledgments. This research is supported by Science and Technology Research and Development Project of Hebei Province (Grant No. 09213502D).
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References 1. Wei, Z., Lin, X.K., Yi, Z.: A genetic algorithm focusing on the problem of partner selection in agile manufacturing. Journal of Harbin Institute of Technology 42(9), 1500–1503 (2010) (in Chinese) 2. Wu, H.G.: Generalized genetic differential evolution for partner selection of supply chain. J. Computer Engineering and Applications 46(25), 246–248 (2010) (in Chinese) 3. Xian, T.W., Yu, C.: Selective methods of collaborative manufacturing strategic partners among enterprises based on genetic algorithm. Journal of Jiangsu University of Science and Technology (Natural Science Edition) 23(5), 399–403 (2009) (in Chinese) 4. Jun, L., Yi, C.X.: Solving Method of Agent Coalition Problem Based on Hybrid Ant Colony and Genetic Algorithm. J. Computer Science 36(4), 227–230 (2009) (in Chinese) 5. Hong, S.W., Xiong, F.Y.: Networked Manufacturing Resource Optimized Allocation for Mass Customization. Journal of Nanjing University of Science and Technology (Natural Science) 34(2), 238–247 (2010) (in Chinese) 6. Geem, Z.W., Kim, J.H., Loganathan, G.V.: A New Heuristic Optimization Algorithm: Harmony Search. Simulation, the Society for Modeling and Simulation International 76(2), 60–68 (2001) 7. Geem, Z.W., Kim, J.H., Loganathan, G.V.: Harmony Search Optimization: Application to Pipe Network Design. International Journal of Modelling and Simulation 22(2), 125–133 (2002) 8. Geem, Z.W.: Optimal Cost design of water Distribution Networks using harmony Search. Engineering Optimization 38(3), 259–280 (2006) 9. Saka, M.P.: Optimum Geometry Design of Geodesic Domes Using Harmony Search Algorithm. Advances in Structural Engineering 10(6) (2007) 10. Vasebi, A., Fesanghary, M., Bathaee, S.M.T.: Combined heat and power economic dispatch by harmony search algorithm. Int. J. Electrical Power Energy Syst. 29, 713–719 (2007) 11. Fesanghary, M., Mahdavi, M., Minary, M., Alizadeh, Y.: Hybridizing harmony search algo-rithm with sequential quadratic programming for engineering optimization problems. Comput. Methods Appl. Mech. Eng. 197, 3080–3091 (2008) 12. Mahdavi, M., Fesanghary, M., Damangir, E.: An improved harmony search algorithm for solving optimization problems. Applied Mathematics and Computation 188, 1567–1579 (2007) 13. Omran, M.G.H., Mahdavi, M.: Global-best harmony search, Appl. Math. Comput. 198, 643–656 (2008) 14. dos Santos Coelho, L., de Andrade Bernert, D.L.: An improved harmony search algorithm for synchronization of discrete-time chaotic systems. Chaos, Solitons and Fractals 41, 2526–2532 (2009)
Supply Chain Optimization Based on Improved PSO Algorithm Xianmin Wei Computer and Communication Engineering School of Weifang University, 261061 Weifang, China [email protected]
Abstract. On the basis of establishment of supply chain optimization model and particle swarm optimization algorithm, an improved particle swarm optimization algorithm is proposed in this paper to solve supply chain optimization problem. In the optimization process, the improved algorithm replaced part of poor fitness value particles to fit fine fitness value particles, so the algorithm has filtering capability, which can speedup the search course and ensure the convergence in global optimal solution. Experimental results are validated and compared with particle swarm algorithm, which indicating that the improved particle swarm algorithm has better performance, and it has simpler, faster and more accurate features. Keywords: PSO, improved PSO, supply chain, Optimization.
effect is used to solve the supply chain node selection optimization company, more satisfactory results have been obtained than the basic PSO algorithm.
2
Mathematical Modeling
Supply chain optimization is combinatorial optimization problem of supply chain business selection. The problem can be stated as, to suppose that supply chain need n subtasks, Task={r1,r2,…,rn}, nodes represents sub-task ri in supply chain network with. Corresponding to a particular task, there are several companies who are willing to complete the task, each node has mi candidate enterprises, from mi enterprise to select a candidate which is suitable for the node enterprise, eventually in the case of synthesizing factor to select n nodes as the optimal combination of enterprises. Candidate company set is Ei={eij j∈[1,mi]}(i=1,2,…,n)which sub-task ri can be completed, performance parameters which enterprise eij completes sub-tasks, including Tij (time) , Cij (cost), Qij (quality) and Sij (reliability), if needed, other parameters can be chosed. T, C, Q and S respectively represents the overall completion time, cost, quality and reliability for entire task. Optimization target of the problem is to select a group of companies B = {b1, b2, ..., bn}, and B ∩ Ei = {bi}, min T, min C, max Q, max S. This is a multi-objective optimization problem, in most cases, there can not be a business collection to meet all of the above objectives. Therefor using the following objective function. minZ=w1T+w2C+w3Q′+w4S′
(1)
Where, wk is weight, you can use expert rating method, AHP and etc. to decide, and w1 + w2 + w3 + w4 = 1. As in the multi-objective optimization model, Q and S are the maximum, while in formula (1) optimization objective function takes the minimum, therefore, definition of Q′and S′ represents the optimization goal. If each sub-task goes on in sequence in the supply chain, then (2)
(3)
(4)
(5) (6)
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Where, t (ri, eij) is time for a candidate enterprise eij to complete the subtasks ri, c (ri, eij) is the cost for a candidate enterprise eij to complete the subtasks ri, q (ri, eij) is quality evaluation for a candidate enterprise eij to complete sub-task ri, s (ri, eij) eij is reliability evaluation for a candidate enterprise eijto complete the subtasks ri. If the combination of certain sub-tasks has parallel implementation, using equation (2) to calculate the time to complete the whole task, and parallel should consider the longest branch to complete. In the supply chain model of node companies selection, to set x = {x1, x2, ..., xn}, where n is the number of tasks, xi is an integer between between 1 and mi, that is a candidate business number for each sub-task. Therefore, using x to indicate an option. For example, in a system which is composed by 10 sub-tasks, each sub-task has four candidates companies to involve in competitive bidding. In programs [3,2,4,2, 2,4,3,1,4,3], the first sub-task is completed by the third candidate participating companies to complete, second sub-tasks is completed by the second candidates companies which involved in the bidding, third sub-tasks is completed by the forth candidate company to complete which involved in competitive bidding, and so on.
3
Particle Swarm Optimization (PSO) Algorithm
Basic PSO algorithm is initialized as a group of random particles (random solutions), in each iteration, particles by tracking the two "extreme" to update theirselves, the first is the best solution which found by the particle itself, and it is called individual extreme point (expressed its position with pbest) , and the other extreme point is the best solution currently found by the whole population, it’s known as the global minimum point (indicated its position by gbest), while the local PSO does not use the whole population but use part as particle neighbors, the best solution in all neighbors is the local extreme point (with lbest indicating its location). The two best solutions are found, according to the following equation (7) and (8) the particles update its velocity and position. Information on particle i can use D-dimensional vector for representation, the position expressed as Xi=(xi1,xi2,…, xid)T , speed is Vi=(vi1,vi2, …, vid)T, the velocity and position updating equation is [5]. (7) (8) From the view point of particle's velocity updating formula, the first part indicates the effects current speed of particles on particles flying, this section provides the particle momentum in the search space flight. The second part is the so-called "individual recognition" section, on behalf of the particles from personal experience, that prompted the particle towards its best experienced position. The third part is the socalled "group cognition" part of the group experience, on behalf of the particles flight path, to promote the best particle position found by the group.
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is the speed in the d-dimensional of particle i at iteration k. is current location of particle i at k iteration in d-dimensional. pbestid is position(coordinates) of individual extreme points of particle i in ddimensional. gbestid is position of the entire population at the global optimal ddimensional. r1 and r2 are random numbers between 0 and 1. c1 and c2 are the acceleration coefficient (or called learning factor), the parameters were used to adjust the particle's own experience and social experience. In its movement, c1 and c2 indicate statistical acceleration item weight towards pbest and gbest position of each particle. Low values allow particles to be back before the lingering outside the target area, and the high value may lead particles in a sudden rush or over the target area. If c1 = 0, then the particle is no cognitive abilities. In the interaction of the particles, it not only can reach the new search space, but also be easy to fall into local optimum. If c2 = 0, no social information sharing between particles, the algorithm is a multi-start random search. if c1 = c2 = 0, particles will remain at the current rate of flight, until it reaches the border. Usually c1, c2 is in [0,4], generally c1 = c2 = 2 [8]. At present, many scholars have tried to improve the parameters of particle swarm optimization algorithm to obtain the desired optimization.
4
Improved Particle Swarm Optimization (IPSO)
4.1
Inertia Weight PSO
In order to maintain the particle inertia, to extend the trend of the search space, and to have the ability to explore new areas. Eberhart and Shi proposed the improvement of the particle swarm algorithm [9-10], which increases the speed updating equation by adding inertia weight w. (9) If w = 0, because the speed itself is not memory, depending only on the particle position and its history, the current best position pbest and gbest, therefore, particle swarm will shrink to the current global best position, more like a local algorithm. If w ≠ 0, particles have extended the trend of the search space, that is a global search capability. Inertia weight used to control the front speed of the current velocity, the larger w can enhance the global search capability of PSO, and the smaller w can enhance local search capabilities. Basic PSO can be treated as w = 1, so in the late of iteration lacking local search capabilities. Many domestic scholars also enhanced the global search capability by changing the PSO inertia weight, and some scholars studied the effects of topological structure and population size on selection of inertia weight.
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Accelerating Convergence PSO
To speed up the convergence rate of population and improve the population's composition, further improvement are made for PSO, the basic idea is to filter the population. First to calculate fitness value corresponding to each individual of the population, excluding part of non-performing individual fitness, then individuals selected from the remaining individual fitness, so that replication goes on these individuals in population, while a number of new individuals randomly are generated , the number of replication and newly generated individual is equal to the number of particles filtered out to maintain the population size unchanged. In this way, particles with fine fitness value replace part of individuals with poor fitness, making the best individual fitness increase in the proportion of the population. In order to avoid prematurely trapped in local optimal solution for search process, it is appropriate to add new individuals to enhance population viability and increase the possibility of the search to the optimal solution.
5
Node Enterprises Selection on Supply Chain Solution with IPSO Algorithm
In this paper, encoding model [11-12] constructed position vector Xi in n-dimensional particles space, which corresponding to the node enterprise selection with n sub-tasks, in which value of Xi represents a candidate business number for each sub-task. Each dimension of particle velocity vector are taken any integer between - (mi-1) and (mi-1), where mi is the number of candidate enterprises for subtasks. Particles in accordance with the formula (9) and (8) to update iteration, in order to ensure each dimension of Xi values for the candidate enterprise number, after each iteration Xi were rounded up processing. Velocity and position of particle are subject to the maximum limit, speed range is [- (mi-1), (mi-1)], the location range is [1, mi]. In model of supply chain optimization node companies selection, the objective function in formula (1) is fitness function. Node enterprises selection on supply chain solution with IPSO algorithm is as follows.
① generate and initialize the parameters of population. ② according to the formula (9) and (8) to update particles, resulting in new populations. ③ calculate the fitness value of each particle. ④ removed poor fitness of particles. ⑤ replication fitness and generate a good number of new particles in particle to maintain constant population size. ⑥ if the fitness of particle i is better than pbesti particle i is updated in the pbesti. ⑦ if the fitness of particle i is better than gbest, the gbest particle update the
current position.
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⑧
to determine whether algorithm reach maximum number of iterations or to meet the accuracy requirements or not, if the conditions are not met, go to Step (3) to continue the search. output global optimal fitness value and its location, the algorithm ends.
⑨
6
Experimental Results Analysis
According to the above algorithm, using C #. Net to design a simulation environment for supply chain node enterprises selection program. The program can enter the different tasks number required, number of candidates enterprises for each sub-task, the completion time, cost, quality index, reliability index and other parameters of of each candidate enterprise. In the improved particle swarm optimization algorithm to find the best scheduling options, the population size is 50, the maximum allowable number of iterations is 400. In this paper all simulation experiments, for each case, are repeated for 15 independent experiments, and the experimental data obtained by averaging. 6.1
Experiment A
To suppose a project composed of 6 sub-tasks, the timing relationship between subtasks is shown in Figure 1.
Fig. 1. Time relationship between subtasks
There were 2,5,4,3,3 and 4 candidate enterprises to participate in bidding for tasks, index weights in optimization objective function were taken w1 = 0.33, w2 = 0.29, w3 = 0.21 and w4 = 0.17. Exhaustive method was first used in the best partners selection of project, selection results and optimizing time were references to the following algorithm application. IPSO and PSO algorithm will be used for both partner selection of the model, Figure 2 and 3 were the convergence of the objective function with IPSO and PSO algorithm respectively. The simulation results has shown that when using IPSO for optimizing the average number of iterations is 197, while using the basic PSO algorithm, the average number of iterations is 258, IPSO algorithm has saved 23.64% of the searching time than the PSO algorithm, so in node enterprise selection of supply chain model, IPSO algorithm is superior to PSO algorithm. In addition, IPSO algorithm and PSO algorithm can be faster than the exhaustive method to find the best candidates for business combinations. When changing the time relationship between sub-tasks we can get the same conclusion.
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Fig. 2. IPSO search results
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Fig. 3. Basic PSO search results
Experiment B
A project was composedof several sub-tasks by the sequence, with the IPSO algorithm to select node enterprises. When increasing the number of sub-tasks, the number of iterations to find the optimal solution is not increasing exponentially, but it is close to linear. Figure 4 is the relationship curve between number of iterations and sub-task, which can be seen from the figure, when the number of sub-tasks increased, the algorithm still has good optimization features.
Fig. 4. Search results with different number of subtasks
7
Conclusion
Aiming at node company selection optimization for supply chain, this paper proposed the improved particle swarm optimization algorithm with a kind of inertia weight and the filtering mechanism. The idea of this algorithm is: to set reasonable PSO inertia weight to enhance global search ability, at the same time used in the evolutionary process, to weed out poor fitness particles with appropriate number, and then copy the better part of individual fitness and a certain number of randomly generated new individuals, to maintain the population size unchanged. In this way, the best individual increases in the proportion of the population, while there are new particles added into the population, which ensuring the possibility of searching the optimal solution. Simulated with C #. Net to obtain more satisfactory results than the basic PSO algorithm, and to verify that IPSO algorithm is the optimal solution with high quality, which has stable convergence and high computational efficiency.
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Acknowledgments. This paper is funded by 2011 Natural Science Foundation of Shandong Province, its project number is 2011ZRA07003.
References 1. Peng, Z.: Supply chain partners game analysis and evaluation selection. Intelligence Journal 2, 59–60 (2009) 2. Ip, W.H., Huang, M., Yung, K.L., Wang, D.: Genetic algorithm solution for a risk-based partner selection problem in a virtual enuerprise. Computers & Operations Research 30, 213–231 (2003) 3. Cao, H.Y., Wang, D.W.: A simulation based genetic algorithm for risk-based partner selection in new product development. International Journal of Industrial Engineering 10(1), 16–25 (2009) 4. Wu, N.Q., Su, P.: Selection of partners in virtual enterprise paradig. Robotics and Computer-Integrated Manufacturing 21, 119–131 (2009) 5. Kennedy, J., et al.: Particle swarm optimization. In: Proceedings of IEEE International Conference on Neural Networks, pp. 1942–1948. IEEE Service Center, Australia (1995) 6. Naka, S., Genji, T., Yura, T., Fukuyama, Y.: A hybrid particle swarm optimization for distribution state estimation. IEEE Trans. on Power Systems 18(1), 60–68 (2003) 7. Gaing, Z.L.: Discrete particle swarm optimization algorithm for unit commitment. In: Proceeding of IEEE Power Engineering Society General Meeting, Toronto, Ontario, Canada, vol. 1, pp. 418–424 (2003) 8. Carlisle, A., Dozier, G.: An off-the-shelf PSO. In: Proceedings of the Particle Swarm Optimization Workshop, pp. 1–6 (2010) 9. Wang, F., Wang, Z., Wang, S.: A dynamic inertia weight particle swarm optimization. China Mechanical Engineering 16(11), 945–948 (2005) 10. Wang, J., Wang, D.: PSO inertia weight in the experiment and analysis. Systems Engineering 20(2), 194–198 (2005) 11. Liu, Z., Zhang, J.: Substation Locating and Sizing Distribution Network based on Multiorganization improved particle swarm optimization algorithm. In: Proceedings of the CSEE, vol. 27(1), pp. 105–111 (2009) 12. Xu, K., Liu, D.: Coevolutionary particle swarm algorithm. Computer Engineering and Applications 45(3), 51–54 (2009)
Registration Algorithms of Dental Cast Based on 3D Point-Cloud Xiaojuan Zhang1, Zhongke Li1, Peijun Lu2, and Yong Wang2 1
Second Artillery Engineering College, Xi’an, 710025, China 2 Beijing University, Beijing 100871, China [email protected]
Abstract. In the optical non-contact measurement process, the reconstruction of complex object depends on the registration of many data. Iterative closest point (ICP) algorithm is a mathmatical method with high level in processing data of 3D Laser Scanning about registration. For the sake of obtaining better registering result, a algorithm including primary registration and fine registration is proposed. It combines algorithm of equal curvature based feature points and improved ICP to register point cloud data automatically. Experimental results are presented and shown the accurate and robust performance of proposed algorithm. Keywords: point cloud registration feature points ICP.
1
Introduction
The 3D laser scanners can produce the surface point clouds data of an object in a few seconds, although only scan an object from one direction at a time. The object must be scanned from different angles for many times to achieve complete figure features. Alignment of these point clouds in one coordinate is registering. Registering is to transform the corresponding points of different angles. This capability has potential application in aero space, medical image processing and surface quality examination. At present there are many registration algorithms about 3D point cloud [1][2] [3][4].The ICP(Iterative Closest Point) algorithm, proposed by Chen and Medioni and Besl and McKay[5][6], has become the dominant method for registering of point clouds. This algorithm has the advantage of high aligning precision. But this method has strict requirement on the relative initial position of point clouds and involves large amount of calculations, and maybe the outcome is not the optimal solution. For this reason, many variants have been introduced on the basic ICP concept[7]. Chen and Medioni refined the algorithm. They use the distance between point and the tangent plane of matching point to replace the distance between point and matching point. Convergence is not working if the curvature of surface changes obviously. In 2004 niloy J. Mitra proposed the registration method based on quadric distance frame, on curve surface and geometric features[8] [9] [10]. In this paper, we proposed an improved ICP algorithm. Out test suggest this method is accurate and fast and stable.
In order to limit the scope of difference between two group of point clouds, we adopt primary registration to enhance the precision of registration and the convergence time in fine registration. To achieve lower computational cost in iterative process, a good primary registration must have the following features:1) Efficient. 2) The outcome must conform to the model as close as possible. The primary registration has the following types: genetic algorithm, three points aligning algorithm and feature-based algorithm[11]. Genetic algorithm is time consuming. Three points aligning algorithm requires accurate corresponding relations of the three base points. Feature-based algorithm can not avoid ambiguous in registration.
Fig. 1. Point cloud primary registration
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In this paper we present a feature-based equal curvature primary registration algorithm (in Figure 1). The curvature of each point is computed first, the relation of point and corresponding curvature is mapped with hash[12]. And then research the curvature to get the feature point of equal curvature. Finally, we use these feature points to conduct the primary registration. In this method the point cloud is simplified with curvature and the comparison is constrained in the scope of equal curvature points, which reduced effectively the number of feature points and simplifies greatly the process of initial registration.
3
Fine Registration
After the primary registration, the two group of point clouds are closer, and the gap between two models are narrower, we can desire desirable outcome if we undertake the fine registration with iterative strategy then. 3.1
Icp and the Methodology
The ICP (originally means iterative closest point, though iterative corresponding point is perhaps a better expansion for the abbreviation) algorithm is relatively steady and robust. It is widely adopted to solve practical problems with the combination of other methods. The ICP algorithm defines the corresponding points set and computes the optimal rigid-body transform repeatedly until the outcome meets certain correct matching convergence rule. The transform function and convergence rule:
Q = Rp i
i
+ T
N
e = q − ( Rp + T ) i −1
i
(1) 2
i
(2)
and Qi are two data point sets. R is rotation matrix, T is translation vector, the function meets the convergence rule when e is at minimum value. This is an optimum matching method based on least square method.
P
i
3.2
The ICP Algorithm Refined with Neighborhood Search
If you have more than one surname, please make sure that the Volume Editor knows how you are to be listed in the author index. The outcome of ICP algorithm is accurate, but this method involves large quantity of computing as well as time for it adopts full scale search. In order to limit the scope of the problem, we only search part of the data and narrow the gap between point clouds by primary registration. 1) Corresponding rule of neighborhood relation In Neighborhood search algorithm, we make the following assumption: points set P and Q has neighborhood corresponding relation and we have two group of points
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'
'
and q . two neighborhood points of one group has corresponding points in another group, the corresponding rule of neighborhood relation is:
Q , qs is the corresponding nearest point of ps , C ( pi ) is the neighborhood set of pi , C ′(q ) is the neighborhood set of qs . In data set P and
s
P( p ∈ P)
(3)
Q (q ∈ Q )
(4)
i
i
p ∈P s
q ∈Q
(5)
s
If p ∈ C ( p ) ,then q ∈ C ′(q ) i s s i That is to say the closest point set
C ′( q ) . Figure 2. s
q
s
of
p
i
in
(6)
Q can be found in the neighborhood
the rule of neighborhood relation
Fig. 2. The rule of neigh borhood relation
2) Neighborhood algorithm From the point of view of the topological relation of points cloud, each point has eight neighborhood points (edge point excluded), the neighborhood algorithm can be put as this: proximity relation C is a 3× 3 region around p in P . C ′ is a n × n region in Q . scan the points in P from left to right, we can search all eight neighborhood points and find ps , once the ps is defined, and the closest point qs for ps is known, we can scan the area of n× n size center qs in Q to search for the closest point of i
p . Usually each candidate point has one closest point. i
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Fig. 3. Neighborhood search algorithm
The following pseudocode describes the neighborhood search algorithm: input:points clouds P and Q ,corresponding neighborhood sets C(P) and C (q ) output:every point Pi in P has approximate value qi of its closest point in Q . /
neighbor _ closest _ po int_ search ( P , Q ) for ( each pi of P ) do
if ( ∃ q closest point of p ∈C( p)) then i
s
s
q = local _ closest _ po int( p , C ′( q )) i
i
s
else
q = global _ closest _ po int( p , Q) i
i
The main steps of fine registration: Iteration: the two point clouds of primary registration are used as new initial position, and the corresponding matching point sets are used as initial registration point sets. The primary registration point clouds:
FP = { p p ∈ R , i = 1,2, m}
(7)
FQ = {q q ∈ R , i = 1,2,n}
(8)
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The closest point:computing the corresponding point
q
i
of point cloud
p ∈ FP , i
and pi − q j → min . The equal curvature primary registration algorithm based on feature points minimized the difference between models and lowered the computing cost of this step. The optimal solution:computing transformations of rotation R and translation T with optimization of analysis method, and Rp + T − q → min . Transformation:transformating FP with attained R and T. Ending iteration:if least square error less than a given threshold ε (ε > 0) ,namely, i
j
d − d < ε , end the iteration. k
4
k +1
Example
We use several point clouds of a tooth model of different angles to evaluate this method.
Fig. 4. Registration of dental cast
We assume ε = 0 . 0000002 . In actual computing, we can extend the limit of threshold constraints if the preset one failed the matching. Fig 4 (a) and (b) are two viewgraph of dental cast. (c) is aligned with ICP algorithm, (d) is aligned with primary registration. (e) is aligned with fine registration. From Fig-4 we can see the result of second alignment is more accurate than the first one. If we only adopt the fine registration, the result may converge to the wrong solution. While if we adopt
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the strategy of primary registration first and then the fine registration, the result will be correct and more accurate. At same time, we examine the four point clouds of the tooth model from four different angles to demonstrate the high registration speed. As shown in Fig-1, this method is more effective in speed than ICP. And this advantage is more apparent with the increasing of the size of the point cloud (in Table 1, point cloud 3 is the outcome of the registration of point cloud 1 and point cloud 2, point cloud 5 is the outcome of point cloud 3 and point cloud 4). Table 1. Registration time of two algorithm
5
Point cloud
Data point
Point cloud 1
32186
Point cloud 2
41520
Point cloud 3
68448
Point cloud 4
52789
Point cloud 5
107514
Point cloud 6
42854
ICP algorithm
time(s) New algorithm Primary Fine registration registration
252.15
154.63
20.10
202.41
122.93
14.55
194.58
76.25
12.88
Conclusion
We have introduced a new registration method that combines equal curvature algorithm based on feature points and neighborhood search algorithm by primary registration and fine registration. We have used examples to demonstrate that this method increases the accuracy and speed of registration. This method would yield more reliability and robustness into the algorithms for real-world. Finally, there is no constraint on the size of point cloud to be computed.
References 1. 2.
3.
Besl, P.J., Mckay, N.D.: A method for registration of 3D shapes. IEEE Transactions Pattern Analysis and Machine Intelligence 14(2), 239–256 (1992) Menq, i.-H., Yau, H.-T., et al.: Automated Preci- sion Measurement of Surface Profile in CAD-Directed Inspection. IEEE Transaction on Robotics and Automation 8(2), 268–278 (1992) Rusinkiewicz, S., Lcvoy, M.: Effcient variant of the ICP algorithm. In: The Third International Conference on 3D Dighn Image and Modeling, Quebec city, Canada, pp. 145–152 (2001)
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5. 6. 7.
X. Zhang et al. Mitra, N.J., Gelfand, N., Pottmann, H., Guibas, L.-n.: Registration of Point Cloud Data from a Geometric Optimization Perspectiv. In: Eurographics Symposium on Geometry Processing (2004) Chua, C.S., Jarvis, R.: Point signatures:a new representaion for 3D object recognition. International Journal of computer Vision 25(1), 63–85 (1997) Ko, K.H., Maekawa, T., Patrikalakis, N.M.: An algorithm for optimal free-form object matching. Computer-Aided Design 35(10), 913–923 (2003) Behzad, K.-P., Behrooz, et.al.: An Open Problem in Matching Sets of 3D Lines. In: Computer Vision and Pattern Recognition, Kauai, Hawaii (2001)
Decoupling Method Based on Bi-directional Regulation Principle of Growth Hormone for Mixed Gas Pipeline Multi-systems Zhikun Chen, Xu Wu, and Ruicheng Zhang College of Electrical Engineering, Hebei United Universtiy, Hebei Tangshan 063009, China [email protected]
Abstract. This paper proposed a bi-directional regulation principle of growth hormone method for gas mixing butterfly valve group. According to the serious decoupling, uncertainty, many disturbances and nonlinear etc of the gas mixing butterfly valve group, the model of the plant is established, application of the decoupling method based on bi-directional regulation principle of growth hormone. Gives a decoupling design for gas mixing valve series system. Simulation results show that the designed controller not only has good decoupling performance, but also ensures good robustness and adaptability under modeling uncertainty and external disturbance. Keywords: Gas mixing, bi-directional regulation, growth hormone, decoupling.
the development of intelligent control, intelligent decoupling control strategy is proposed by Ren Hailong. They through analysis the law and the physical structure of the gas mixture pressure process, they divided the control loop into two: calorific value and the pressure decoupling control loop, pressure control loop. In this paper, they design the intelligent decoupling control strategy for the calorific value and the pressure decoupling control loop. However, due to the two valves Series on the blast furnace gas pipes and the two valves series on the coke oven gas pipes is very close. The literature one pointed that :this is a typical strong coupling system. Document 5-7 was not performed detailed design. Although, the literature 1 has been decoupled the two valve system based on feedforward compensation. but the system has the blast furnace gas pressure changes,coke oven gas pressure change and changes in user traffic disturbance. So, ability of this system that inhibition disturbance is not strong. So, a new decoupling control method based on bi-directional regulation principle of growth hormone was applied to gas mixing butterfly valve group. So far,decoupling method based on bi-directional regulation principle of growth hormone has just started,there are few examples used in industry. Therefore, this paper was applied it to the gas mixing process, to remove the coupling between systems.
2
Mathematical Model of the Mixing Gas Pipeline System
In the blast furnace, coke oven gas pressure during the mixing, when the controller to calculate the control values of coke oven and blast furnace valve group, the butterfly valve controller according to the series gain matrix to decision that how to adjust the two valves of corresponding valve group in the end. Due to the basic idea of the pressure distribution essentially the same of blast furnace values and coke oven values,following,for example by coke oven butterfly group. Butterfly valve series system specifically for the following:
Fig. 1. Pipe system of pressure-flow
In the fig 1, P0 is coke oven gas pressure befer the number one butterfly valve. P1 is coke oven gas pressure befer the number two butterfly valve. P2 is coke oven gas pressure before the number two butterfly valve. u1, u2 are the opening of number one and number two butterfly valves. Q is the gas flow of coke oven pipeline. According to the literature12,pressure-flow process can be described as
Q = u1 ( P0 − P1 ) = u2 ( P1 − P2 ) =
u1u2 ( P0 − P2 ) u1 + u2
When two loops are in open loop,the first amplification factor is
(1)
Decoupling Method Based on Bi-directional Regulation Principle
∂Q ∂u1 u
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2
2 = const
u2 = ( P0 − P2 ) u1 + u2
(2)
Closed loop pressure, the first amplification factor is
∂Q ∂u1
= P0 − P1 = P1 = const
u2 ( P0 − P2 ) u1 + u2
(3)
According to the definition of a relative gain
λ11 =
∂Q ∂u1
u2 = const
∂Q ∂u1
P1 = const
=
u2 u1 + u2
(4)
From equation (1) and solve for u1 and u2 into equation (4).can be used pressure to represent the gainm,is
λ11 =
P0 − P1 P0 − P2
(5)
can also find the relative gain of the u2 and flow Q,is λ12
λ12 =
P1 − P2 P0 − P2
(6)
If use P1 to describe the pressure-flow system,is
P1 = P0 −
Q Q u P +u P = P2 + = 1 0 2 2 u1 u2 u1 + u2
(7)
Another gain can be determined, to strike a partial derivative for equation (7), can be, respectively derived the relative gain of u1, u2 for two channels of the P1. Then, pressure—flow system of input-output relationship can be expressed by relative gain matrix as
If in the system P1 close to P2,Λ is very close to the unit matrix, instructions to control the flow with a valve 1, with a valve 2 to control pressure P1 is appropriate. If P1 close to P0, use valve 2 to control flow and with a valve 1 to control pressure P1 is appropriate.if P1 close to the midpoint of (P0-P2), while adjusting the two valves are the best. Known,a system of coke oven gas pipeline pressure is P0=6.2kPa,P1=5.5kPa, P2=5.0kPa,The gain matrix is
λ Λ = 11 λ 21
λ12 0.58 0.42 = λ 22 0.42 0.58
λi,j very close to 0.5,its shows that there are serious coupling in this system. From equation (8),we could be find the mathematical model of this control system can be expressed as
y1 ( s) u1 ( s) = G ( s ) Λ y (s) u ( s ) 2 2 Among,
(10)
y1 ( s) = Q( s ) and y 2 ( s ) = P( s ) G ( s) = diag {G ( s), G ( s )} is transfer
function of controlled object. In debugging the process of trial and error
G1 ( s ) =
K , In the equation, K = 2, T0 = 1.5 T0 s + 1
3
Decoupling Control Design
3.1
The Overall Design of Decoupling Control
。
The overall design of decoupling control system shown in Figure 2.
Fig. 2. The overall design of decoupling control system
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Among, R1 ,R1were given values, Y1 ,Y1were output values. 3.2
Decoupling Algorithm
Fig. 3. Decoupling control block diagram
Decoupling control block diagram shown in figure 3 In order to facilitate description,defined as variable: 1)uc1, uc2 are the output signals of control module A and control module B. 2)u11,u12 were control unit A assigned to them own and the output signals of control module B; Similarly u21,u21 were control unit B assigned to them own and the output signals of control module A. 3)output signals of Control units A and B is u1 = u11 + u 21 u 2 = u 22 + u12 For a TITO object
和
。
x1 a11 x = a 2 21
a12 x1 b11 + a 22 x 2 b21
y1 c11 y = c 2 21
c12 x1 c 22 x2
b12 u1 b22 u 2 (11)
Among, x1,x2 are state variables;y1,y2 are output variables,u1,u2 are input variables,Traditional Non-decoupling control signal, In addition, only consider the matrix C is the unit matrix, That is state variables also are output variables. In this case, if the state variable to stabilize the control, The output variable can also be stability control.so, In the design of decoupling control algorithm does not take into account the impact of matrix C. if the coupling between input variable uiand state variables xi (i,j=1,2)are completely eliminated. Then the coupling of input variables ui and output variables yi can be eliminated. The following, describes the decoupling control algorithm of control unit A.
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In order to achieve that adjustment x1 , x2 is unchanged, to eliminate the coupling between input variables u1 and process variables x2. So the right term in the second equation of the type (11) should be equal to zero.
a 21 x1 + a 22 x 2 + b21u1 + b22 u 2 = 0
(12)
Because x2 stability constant,so a22x2 can be regarded as constant.then
a 21 x1 + b21 (u11 + u 21 ) + b22 (u 22 + u12 ) = −a 22 x 2 = ω
(13)
In the equation, ω is a constant.the process of adjustment x1,just make sure the left of equation (13) to the same,can eliminate the coupling effect between u1 and x2.so
To verify the feasibility of the control program, figure 3 shows the block diagram of the simulation test.
(a)Flow setpoint step change
(b)Pressure setpoint step change Fig. 4. Butterfly valve series system decoupled response curve
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For the nominal state, two channels each with unit step value were given,the simulation results shown in figure 4.Figure(a)is response curve of flow channel for a given value of the step change. Curve 1 is the curves of flow, curve 2 is curves of the pressure;figure(b)is response curve of pressure channel for a given value of the step change. Curve 1 is the curves of pressure, curve 2 is curves of a flow. Visible, Although the coupling of two valve series system is more serious, but decoupling through decoupling method based on growth hormone two-way adjustment mechanism, when the flow rate Q changes, pressure remained almost unchanged, and the output is no static error, decoupling works well, and vice versa.
5
Conclusions
This paper use decoupling method based on bi-directional regulation principle of growth hormone to remove gas mixing system coupling. Simulation results show that the control system not only has better tracking performance, Anti-disturbance ability, and the decoupling works well, to solve the gas mixture system valve in series strong coupling, time-varying, confounding factors such as more adverse impact on the system. so, the control method has good prospects. Acknowledgments. This work was supported by the Natural Science Foundation of Hebei Province (grant number:F2009000796).
References 1. 2. 3. 4. 5. 6. 7. 8. 9.
Qin, l.: Decoupling and Smith compensator with a mixture of gas heating value control. Control Engineering, 73–75 (2002) Meng, c., Xia, c.: SMAR intelligent regulator and control of mixed gas calorific value. Hebei Metallurgical, 53–55 (2002) Wu, x.f., Sun, h.f., Wei, c.y.: Automatic control of furnace gas pressure regulator. Metallurgical Automation, 64–65 (2002) Huang, j.m., Cao, j.m.: Computer-controlled system of gas mixing. Automation and Instrumentation, 28–30 (2000) Ren, h.l, Li, s.y.: Mixture gas pressure and calorific value of the fuzzy decoupling control. Automation Instrumentation, 65–67 (2004) Cao, w.h., Wu, m., Hou, s.y.: Method and application of gas mixture pressurized process intelligent decoupling control. zhong nan University News, 780–785 (2006) Guo, j.: Intelligent control of blast furnace, coke oven gas pressure and calorific value of mixture. Xinjiang University News: Engineering Edition, 231–235 (2001) Liu, B., Zhang, Z.: Decoupling control based on bi-directional regulation principle of growth hormone. Journal of Southeast University, 5–8 (2006) Jin, y.h., Fang, c.z.: Process Control. Tsinghua University Press, Beijing (1995)
Research on Association Rules Parallel Algorithm Based on FP-Growth Ke Chen1, Lijun Zhang2, Sansi Li1, and Wende Ke1 1 Department
of Computer Science and Technology, Guangdong University of Petrochemical Technology, Guangdong, China 2 School of Information & Mechanical Engineering, Beijing Institute of Graphic Communication, Beijing, China [email protected]
Abstract. In view of the FP-Growth algorithm needs to establish huge FP-Tree to take the massive memories, when is confronted with very huge database, its algorithm obviously insufficient in efficiency, This article unified FP-Growth and Parallel Algorithm, proposed one kind association rule parallel algorithm based on the FP-Growth, this algorithm in the FP-Growth algorithm foundation, with the aid of parallel algorithm's thought that carried on the database resolution as well as the FP-tree tree the division reasonable combination, In the task allocation, the load stabilization, has done the research, the duty rational distribution, the combination, has achieved the good load stabilization, raised the algorithm speed, this algorithm is suitable in the large-scale database carries on the data mining, compared with former algorithm had the remarkable enhancement in the efficiency. Keywords: FP-Growth, Association Rules, parallel Algorithm, Load Balancing.
The parallel computing is refers to the parallel machine, decomposes an application divide into the child duty, assigns for the different processor, between each processor coordinates mutually, parallel holds the displeasing person duty, thus achieves accelerates to solve the speed, or solution application question scale goal [2]. 2.2
Basic Conditions of Parallel Computing
(1) Parallel machine. The parallel machine contains two or two above processors at least, these processors through the interconnecting network interconnection, correspond mutually. (2) Application question must have the degree of parallelism. That is, the application may decompose into many sub-duties; these sub-duties may parallel carry out. Decomposes an application into many sub-duty processes, is called the parallel algorithm the design. (3) Parallel programming. Provides in the parallel machine in the parallel programming environment, realizes the parallel algorithm specifically, the establishment parallel program, and moves this procedure, thus achieves the parallel solution application question the goal. 2.3
Parallel Computing Typical Algorithms
Task Allocation Algorithm. The duty most superior assignment, put n task allocation for n processor to carries out, the i processor carries out the time which the j duty needs is cij, we design one to be most superior n task allocation for n processor execution and the worst plan, causes the benefit which produces to be most superior or worst. Proposes the data-in by the document, the document first line has positive integer n, indicated that has n duty to assign for n processor carries out, The n line in then, each line has n integer cij,1≤i≤n,1≤j≤n, expressed that the i processor carries out the benefit which the j duty needs. Analysis: The variable xij expression the j task allocation for the i processor in the
execution, the assignment problem may indicate for following linear programming question [3]. Load Stabilization Question. The different duty, when each processor were carries out , how to use the most superior method transporting to cause quantity same which assigns in n processor [4]. Analysis: Supposes each processing node duty quantity is xi, must make each processor node duty quantity to be the same, namely each processor's duty number n
xi / n , Therefore some processor node must call in the duty, some processor becomes i =1
node must assign out the duty, the i processor node calls in the duty to the j processor
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node time is min{|j-i|,n-|j-i|}. If m duty has n processor node, the ith processor node has the ai unit's duty, the jth node needs to complete bj task, the task call is balanced, m
n
ai = bi , from the ith processor node Calls to the jth processor time is cij, the that i =1 j =1 most superior plan assigns out the xij unit's duty from the ith processor to the jth processor node, may indicate is[5]: m
n
min ci j xij i =1 j =1
m
x
ij
i =1
n
x
ij
(1)
= bj
j = 1,2,..., n
(2)
= aj
i = 1,2,..., m
(3)
j =1
x i ≥ 0, i = 1,2,..., m, j = 1,2,..., n j
3
Association Rules Parallel Algorithm Based on FP-Tree
3.1
Algorithm Ideas
(4)
The frequent pattern tree excavation algorithm, first, scans the database to form the frequent 1 item set, and will obtain the data item according to the descending order, simultaneously deletes the support is smaller than the smallest support project, Then, the division candidate item set for many modules and uses main from the pattern parallel algorithm, the main engine allocating task to the different processor node, causes the frequent pattern storehouse to become a smaller module, through task allocation to different processor node, thus the urge treatment speed[6]. The steps: (1) first, scans the database to form the candidate1 item set, if the candidate support is smaller than the smallest support, we delete them. (2) Division candidate1 item set to the different processor node, forms the FP-tree tree, and maintains their related information. (3) Uses main pattern, excavation separately the allocating task to the different processor node and carries out the FP-tree algorithm. (4) By the main engine collection the information which completes from different processing node processing, and carries on compiles. (5) Output. 3.2
The FP-Tree Parallel Algorithm Carries out Process
Parallel Algorithm step (1)Task partition, put a big task divide the line into a lot of sub- task with smalls, and assigns them to the different processor point.
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(2) Correspondence exchanges information mutually at the different processor node. (3) Combination makes the task able to more effectively assign each processor. (4) Reflect, assign task to distribute different processor node to carry on a processing. Example :( 1) Scan database to form multifarious item (minimum support is: 2) Table 1. The first set of frequent TID 100 200 300 400 500
Item set a, p, c, m, f, g p, b, a, c, g, f f, a, b, y g, c, f y, c, a, m, f
item set after compositor f, a, c, g, p, m f, a, c, g, p f, a, y f, c, g f, a, c, m, y
(2) Establish FP-tree tree
Fig. 1. The tree of frequent pattern
(3)Establish condition mode database for each node Table 2. Conditions pattern library Item set a c g p m y
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(4) Establish the condition mode of FP-tree tree Output result: Table 3. For example (the minsupport is: 2) TID 100 200 300 400 500 600 700 800 900 1000 ……
3.3
Item set a, c, d, b, f, e f, c, d b, f, d, c, e e, d, c, f, b c, b, a a, c, n, m, e m, b, n, c, a c, b c, a, m, b, e c, a, m ……
Multifarious item c, b, d, f, e, a c, d, f c, b, d, f, e c, b, d, f, e c, b, a c, a, m, e, n c, a, m, b, n c, b c, a, m, b, e c, a, m ……
Cpu
Cpu1
Cpu2
Cpun
Experiment Result
Respectively with two and three processors of different arrangements start experiment, CPU and memory respectively is: 2.0GHz (dual), 1G; 1.60(dual), 2G; 1.73GHz, 0.99G. Test sources of date in: http://archive.ics.uci.edu/ml/data-sets.html. From experiment, we discover that the more the processor, the little execution time, tests result as follows:
Fig. 2. The Comparison of the process time
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4
FP-Growth Parallel Algorithms Based on Split
4.1
Design Thought of the Algorithm
For keeping the relativity of database data uninfluenced, put forward one kind to reserve whole database relativity don't change, The calculate way of FP-Tree cent piece, and adopt the node of tree count method, divide equally the FP-Tree to the different node, keep a good load balance, This method can shorten the length of building up the FP-Tree, and keep the relativity of of good data, At the same time, considered load balance and task allotment of excellent , pass to carry on FP-Tree cent piece a data of excavation, the calculate way can adapt to the data excavation of more large-scale database, can raise data excavation speed further and has been tested verify the calculate way to apply effectively[7]. 4.2
Algorithm Simulation
If exists has P1, P2,…, Pn altogether N non-shared structure CPU, between them the resources are mutually independent, merely through network transmit message. But DBi(i=1,2,…, n) is the memory in Pi the Taiwan CPU business database, business has n
the Di strip, total business database DB = DBi , The general affairs several D = Di , n
i =1
i =1
The FP-Tree parallel computing is also works through N CPU, the processor processes own data merely, between each CPU only through network transmit message, finally result Collection on Master machine[8,9] 4.3
Experimental Results
The experiment environment and the parameter are as follows: The algorithm realizes with the C language, uses CPU is: Pentium T4200 2.00GHz; Memory: 1G; Operating system: Windows XP; Parallel environment use: mpich.nt.1.2.5, experiment data set: 40110D102K.dat and T1014D102K.dat (//http:fimi.e8.helsinki.fddata/)[10]. Table 4. 40110D102K.dat the data of set (the result of four nodes process) Support (%) 1.5 2.0 3.5 2.5 3.0
Node 1 0.41 0.22 0.03 0.10 0.03
Node 2 0.43 0.23 0.03 0.10 0.03
Node 3 0.43 0.24 0.035 0.12 0.02
Node 4 0.45 0.20 0.05 0.15 0.01
Research on Association Rules Parallel Algorithm Based on FP-Growth
Fig. 3. The compare from the time of different nodes process Table 5. 40110D102K. dat the data of set (the result of four nodes process) Support (%) 9 8 7 6 5
Node 1 4.90 6.00 8.82 10.25 13.05
Node 2 3.66 5.55 8.33 9.98 12.00
Node 3 3.69 6.35 7.25 9.65 11.66
Node 4 3.95 6.62 8.63 12.25 15.05
Fig. 4. The compare from the time of different nodes process
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Summary
This article in view of the connection rule's classical algorithm FP-Growth algorithm, proposed regarding this algorithm's parallel algorithm, this algorithm does not need to scan the database many times, also does not need to have the candidate item set, This article in view of the connection rule's classical algorithm FP-Growth algorithm, proposed regarding this algorithm's parallel algorithm, this algorithm does not need to scan the database many times, also does not need to have the candidate item set, This text puts forward of reserve the calculate way of piece that the connection information carries on a cent to the FP-Tree, use this method, reserved the connection information of database. Assign task in the different processor to carry on excavation respectively, raised the efficiency of the calculate way, the calculate way also was applicable to a large-scale database to carry on data excavation.
References 1. She, C.: The data mining algorithmic analysis and the parallel pattern study, vol. 3, pp. 44– 56. University of Electronic Science and Technology of China, Chengdu (2004) 2. Zhang, L.b., Chi, x.B., Mo, Z.Y.: Parallel Computing Introductory Remarks 7, 3–5 (2006) 3. Wang, G.-r., Gu, N.-j.: An Efficient Parallel Minimum Spanning Tree Algorithm on Message Passing Parallel Machine. Journal of software 11 (2006) 4. Hu, k., Cheung, D.W., Xia, S.-w.: Effect of Adaptive Interval Configuration on Parallel Mining Association Riles. Journal of Software 11 (2004) 5. Shuichi, S.: Synchronization and Pipeline Design for a Multithreaded Massively Parallel Computer (March 1992) 6. Han, J.W., Pei, J., Yin, Y.W., Mao, R.Y.: Mining frequent patterns without candidate generation: a frequent-pattern tree approach. Data Mining and Knowledge Discovery 8, 53–87 (2004) 7. Wang, G.-r., Gu, N.-j.: An Efficient Parallel Minimum Spanning Tree Algorithm on Message Passing Parallel Machine. Journal of Software 11 (2004) 8. Liu, X.: Research and apply of the connection rule based on FP-Growth calculate way 4, 6–7 (2006) 9. Hu, Y.: Study on data mining algorithm based on the connection rule, vol. 8. Dalian Maritime affair University (2009) 10. Mao, Y.: The connection rule excavation related algorithm study, vol. (6), pp. 8–9. Southwest Jiaotong University (2009) 11. Qiu, R., Lan, R.: Highly effective FP-TREE foundation algorithm. Computer Science 3, 98–100 (2004)
Multi-Objective Optimization Method Based on PSO and Quick Sort Xie Shiman and Shang Xinzhi College of Mechanical Engineering, Hebei United University, 063009 Tangshan, China [email protected]
Abstract. Study the particle swarm optimization algorithm for solving multiobjective optimization problems. This paper presents a set select space of multiobjective particle swarm optimization algorithm (SMOPSO) based on the Pareto dominate relations, using the method of fast sort to construct nondominated solution set, pre-set an upper limit of non-dominated solution space, and set an external set to save the optimal solutions. At the same time introduce genetic algorithm crossover and mutation operator for each generation of the updated part of the particles in order to increase the diversity of particle groups, so we can get good distribution of particles. The simulation results verify the validity of this method. Keywords: Multi-objective optimization, PSO, improved quick sort.
objective in each successive generation. The fitness value of the every single objective could be used to evaluate the pros and cons of each particle [10]. The algorithm proposed by Mohkami used the penalty function method to solve the constraint problems of equality and inequality [11].
2
Improved the Multi-Objective Particle Swarm Optimization Algorithm
In this paper, an improved select space multi-objective particle swarm optimization was proposed based on the study on particle swarm optimization algorithm for solving multi-objective optimization. The method applied an improved quick sort method to construct the non-dominated solution set. The upper limit of the nondominated solution select space was set. At the same time, the optimal solution set was conserved by the use of the external set. The crowding degree operator was used to guide the uniform distribution of the particles. The external set was updated by the use of the concept of Pareto dominance. The crossover operator and mutation operator were introduced in order to increase the diversity of particle swarm. 2.1
Related Operators in SMOPSO Algorithm
2.1.1 Increasing Capacity of External Set In order to improve calculate efficiency, the method of external set capacity variable is used. Because the more particles in the external set, the greater of calculation amount. Firstly, only set the capacity of the external set space 10% of its maximum capacity, and then as the generation increases, the capacity of space increases; while the iterative generation reaches 90 ×Iter, the capacity of space reaches the maximum. The formula is as follows:
％
space _ Iter × (0.1 + t / Iter ), t < 0.9 × Iter space _ num = space _ Iter , otherelse
(1)
Where Iter is the greatest generation; t is the current generation; space_Iter is the maximum capacity of the external set; space_ num is the current capacity of the external set. 2.1.2 Crowed Comparison Operator Based on Pareto Crowed comparison operator used to limit the number of particles in the external set space. The following steps calculate the crowding degree: space(i)_dist represent the max
min
each particle’s crowding distance; f m and f m is maximum and minimum value of the target at population of this generation. The process is as follows: a) Get the particle number of space; b) Initialize the crowding distance; c) Calculate the crowding distance of every particle in space:
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For each target value of the numerical size of the particle sorting, and give the maximum crowding degree for the boundary of the particle, in this article we set the value as 10, that is:
space(1) _ dist = space( L) _ dist = 10
(2)
The calculation formula for the middle of the remaining particle crowding is:
space(i ) _ dist = space( L) _ dist + space(i + 1) _ m −（space(i + 1) _ m /( f mmax − f mmin ))
(3)
Suppose the particle number is M in space, selecting N particles by the Pareto dominance relations (N> M), and use the crowding degree operator, calculate the crowding degree space(i)_dist of every particle, then select the M particles which has high crowding degree value into space . 2.1.3 Mutation Operator and Crossover Operator a) Mutation operator As for Particlei ,G : i = 1, 2, , N , we can get a new particle Particlei ,G from the following:
Here r 1, r2 , and r 3 are random and different values between 0 and N, and different from the subscript index i, variation factor F is a constant between 0 and 2, its main role is to control the magnification level of the particle position’s change.
b) Crossover operator According to the updated particle position Particle i, by the crossover strategy to make a random selection of two or more particles to exchange part of the code, and thus form new particles. The new particles after crossover operation are as follows:
(j=1,2,…,D) Rand (j) is the uniform distribution probability between 0 and 1, CR is the predefined crossover probability, CR (0,1) , mbr(i) represents the random value between 1 and D.
∈
2.1.4 Improved Quick Sort Method for Non-dominated Solutions Select a particle x from the particle group randomly, and then let the other particles in the group compare with the x in turn. By comparing the population is divided into particles by x-dominated set and will not be x-dominated set. If x is not dominated by
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any particle, we put x in the no dominated set, and then for the not to be x-dominated set to repeat this process until the particles not to be x-dominated set is pop. Since only particles in the not to be x-dominated set is possible to enter non-dominated set, so we can narrow the compare range. The method of non-dominated quick sort arranges the particles in the population orderly according to the strength, and then incorporates the non-dominated solutions which are at the forefront in external space of storage. But this method cannot use the particles around the non-dominant solutions fully. Though these particles are not the optimums to be seeking, they are benefit to guide the particles searching the other regions of the front part of Pareto in the process of evolution. Based on this, the paper develops improved multi-objective particle swarm optimization which is set up with screening limitation. If the number of the non-dominated solutions reaches the limitation, there is no difference comparing to the normal quick sort. However, if the number of the non-dominated solutions doesn’t reach the limitation, some suboptimal solution particles which are at the front of the method of quick sort is selected to go into the external space, and then the ability of optimization is improved. 2.2
Algorithm Process of SMOPSO
Step1 Initialize population: Select the number of times of iteration, particle number is part size; in the feasible region of the decision-making variables, randomly generated initial position of each particle particlei, as well as the individual optimal position part trace; the initial velocity of every particle is random value between 0 and 1. Calculate the target value of every particle, and set extreme value part_gbest of individual particle as itself; Step2 Using the improved non-dominated solutions to quick sort the particle group dominating relations, and save the non-dominated solution which is produced by each generation into space ; Step3 Begin the loop operation; Step4 Use loop to update the particle velocity and position: For i=1 to partsize (1) Randomly select a non-dominated particle position as global optimal solution part _ gbest of the ith particle from space; (2) Update the velocity veli and the position particlei of the particle; (3)As for the updated particle swarm randomly selected population in which the number of individuals associated with the part of the number of particles of the crossover and mutation operator in order to enhance the diversity of groups of particles; (4)for the particles whose position particle are beyond the feasible region, then within the region were randomly assigned to one of its new location to ensure that groups of particles are always carried out within the scope of the feasible region of optimization calculation; End Step5 Calculate the target value of each particle;
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Step6 Update the individual extremum: here use the concept of Pareto dominant solutions, if the current position of the particle i govern their individual extremum, and then update the individual extremum: part_ gbest = particlei , in order to increase the diversity of dominant solution, if the current position of particle i and its extreme position of the individual does not dominate each other they will also update their individual extreme value, and if individual extremum position of the individual particles to dispose of their current location, then the individual extremum position of the individual is not updated; Step7 Update the external set space; external set stored the non-inferior solutions as part of sub-optimal solution which are generated by each generation do not dominate each other, with the growing evolution of generation, the non-dominated solutions between different generations are likely to be dominated by another, And therefore, sorting space which is based on Pareto to select the final non-dominated solutions, The algorithm will also end up with space of the solution set; (1)Combine the non-dominated set which is produced by particle swarm of each generation into the space, according to Pareto dominance relationship to select the optimal solution and save the result to the space; (2) Set the capacity of space, and limit its particle number. If the number beyond the limited value, use crowed comparison operator to select the optimal solution again, limit the number of particles in the space within the specified scope; Step8 To determine whether to satisfy the termination criteria; if not, then return to Step3.
3
Simulation
3.1
Evaluation Indicators of the Algorithm
Evaluation of a multi-objective optimization algorithm performance can from three aspects to consider: 3.1.1 Generational Distance The concept of generational distance is used to estimate how far the elements in the set of non dominated solutions are from those in the Pareto optimal set. And therefore GD is computed as follows:
GD =
n i =1
d i2 / n
Where n is the number of the no dominated solutions generated by the algorithm, di is the Euclidean distance between solution i from the set of n non-dominated solutions found and the closest element from the Pareto optimal set(in objective space). The smaller value of GD, the more close to the theoretical solution obtained optimum region. Nowadays, most theory of the test functions of the Pareto optimal solutions are known to algebraic expressions; it makes the performance evaluation of convergence possible.
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3.1.2 Spacing(SP) Spacing is used to measure the range variance of the neighboring solutions in the known Pareto front, it is defined as:
SP = Where d i
n i =1
(d − d i ) 2 / (n − 1)
= min( i =1 f mi − f mj ) , i, j = 1, , n, n
the no dominated solutions generated by the algorithm;
i≠ j
n is the number of
d d is the mean value for all
d i ; A smaller value of SP will indicate that the solutions are uniformly spaced 3.1.3 Computing Time Computing Time is used to evaluate the fast of the algorithm. 3.2
Simulation
In order test the validity of MOPSO, we compare it with NSGA-II and MOPSO. The greatest generation in NSGA-II algorithm is 200, crossover probability is 0.8, and mutation probability is 0.1. the parameters in SMOPSO are as follows: c1 = 1 ,
c2 = 3 , inertia weight is reduced linearly, crossover probability is 0.15, mutation probability is 0.05, the capacity of space is 200, the non-dominated solution set quickly sort space upper limits is 0.35 times of the capacity size of space , the greatest generation is 150. The capacity of space MOPSO algorithm is 200, the population size of every algorithm is 150.The experiment environment is: CPU Intel Pentium-IV 2.80G, 512M memory, Programming using Matlab7.0.4. Fig. 1 shows the performance of the NSGA-II method. Fig. 2 shows the performance of the MOPSO method. Fig. 3 shows the performance of the SMOPSO method. And every algorithm run for 20 times separately, then get their average value, and every evaluate indicators presented in Table 1. Test function:
min f1 ( x ) = x1 min f 2 ( x ) = g ( x )(1 − x1 / g ( x )) n
g ( x ) = 1 + 9 / ( n − 1) xi i =2
xi ∈ [0,1], n = 30, i = 1, 2, , n In
the
theory
the
xi ∈ [0,1], xi = 0, i = 2,3,, n
Pareto
Front
is
f2 = 1 −
f1
,
where
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Fig. 1. Pareto front got by NSGA-II
Fig. 2. Pareto front got by typical MOPSO
Fig. 3. Pareto front got by SMOPSO Table 1. Evaluation criteria of three methods
GD NSGA-II MOPSO SMOPSO
9.558 ×10e − 4 0.001432 3.35 ×10e − 4
SP 0.00452 0.00566 0.00202
Time(s) 164.08 118.087 147.5
From Table 1 we can get that, basic MOPSO in the calculation of time has obvious advantages, but its effects and distribution of convergence is not satisfactory; The SMOPSO has the best performance on the convergence and distribution, and its runtime is medium. So, SMOPSO has good overall performance.
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The number of comparison is effectively reduced and computational efficiency is improved by improving the quick sort method for non-dominated solutions. The application of crowed comparison operator, crossover operator and mutation operator has improved the rationality of the population distribution. Simulation results have shown the validity of the multi-objective particle swarm optimization algorithm proposed in this paper for solving multi-objective optimization problems. Such results are of certain significance in the application of particle swarm optimization algorithm for solving multi-objective optimization problems. The function of each technology in this hybrid method and the rapidness of the algorithm need further study.
References 1. Kennedy, J., Eberhart, R.C.: Particle swarm optimization. In: Proceedings of IEEE International Conference on Neural Networks, pp. 1942–1948 (1995) 2. Bergh, F.V., Engelbrecht, A.P.: A study of particle swarm optimization particle trajectories. Information Sciences 176(8), 937–971 (2006) 3. Praveen, K.T., Sanghamitra, B., Sankar, K.P.: Multi-Objective Particle Swarm Optimization with time variant inertia and acceleration coefficients. Information Sciences 177(22), 5033–5049 (2007) 4. Haiyan, L., Pichet, S., Yong, H.S., Tharam, D.: Experimental study of a new hybrid PSO with mutation for economic dispatch with non-smooth cost function. International Journal of Electrical Power & Energy Systems 32, 921–935 (2010) 5. Deming, L.: A Pareto archive particle swarm optimization for multi-objective job shop scheduling. Computers & Industrial Engineering 54, 960–971 (2008) 6. Sha, Y., Hsing-Hung, L.: A multi-objective PSO for job-shop scheduling problems. Expert Systems with Applications 37, 1065–1070 (2010) 7. Clerc, M., Kennedy, J.: The particle swarm-explosion, stability, and convergence in a multi-dimensional complex space. IEEE Transactions on Evolutionary Computation 6(1), 58–73 (2002) 8. Parsopoulos, K.E., Vrahatis, M.N.: Particle swarm optimization method in multi-objective problems. In: Proceedings of 2002 ACM Symp. Applied Computing (SAC 2002), Madrid, Spain, pp. 603–607 (2002) 9. Moore, J., Chapman, R.: Application of Particle Swarm to Multi-objective Optimization: Department of Computer Science and Software Engineering. Auburn Univ. (1999) 10. Tavakkoli, M.R., Azarkish, M., Sadeghnejad-Barkousaraie, A.: A new hybrid multiobjective Pareto archive PSO algorithm for a bi-objective job shop scheduling problem. Expert Systems with Applications 38, 10812–10821 (2011) 11. Mohkami, H., Hooshmand, R., Khodabakhshian, A.: Fuzzy optimal placement of capacitors in the presence of nonlinear loads in unbalanced distribution networks using BF-PSO algorithm. Applied Soft Computing 11, 3634–3642 (2011)
A Rough Set-Based Data Analysis in Power System for Fault Diagnosis Dajiang Ren Zhangjiakou City, Power Supply Bureau, Zhangjiakou Hebei 075000, China [email protected]
Abstract. The fault in power system cannot be completely avoided. In this paper, we developed a method to resolve fault localization problems in power system. Though the data acquisition process has been highly automated, the process of assimilating and analyzing data still lags behind. Raw data must be transformed into knowledge in order to help users decide how to respond to the event and implement the necessary actions. A promising technique for substation event analysis using rough set theory is described in this paper. It interprets the data and outputs meaningful and concise information, which improves the performance of a data analysis system and help with the knowledge acquisition process. A substation model was developed to generate various fault scenarios for our case studies to evaluate the performance of the rough set algorithm. The results show that it works well and efficiently with the overwhelming data. Keywords: Rough set, Fault diagnosis, Rules extracting of reduct.
1
Introduction
Electrical power system is one of the most complex artificial systems in this world, which safe, steady, economical and reliable operation plays a very important part in social economic development, even in social stability. A fault is defined as a departure from an acceptable range of an observed variable or calculated parameter associated with systems. It may arise in the basic technological components or in its measurement and control instruments, and may represent performance deterioration, partial malfunctions or total breakdowns [1-2]. Fault analysis implies the capability of determining, either actively or passively, whether a system is functioning as intended or as modeled. The goal of fault analysis is to ensure the success of the planned operations by recognizing anomalies of system behavior. A system with faults does not necessarily imply that the system is not functioning. Detecting a fault involves identifying a characteristic of the system, which when a fault occurs, can be distinguished from other characteristics of the system. Fault diagnosis is a complex and difficult problem that concerns effective decisionmaking [3-4]. Carrying out timely system diagnosis whenever a fault symptom is detected would help to reduce system down time and improve the overall productivity.
Due to the knowledge and experience intensive nature of fault diagnosis, the diagnostic result very much depends on the preference of the decision makers on the hidden relations between possible faults and the presented symptom. In other words, fault diagnosis is to rank the possible faults accordingly to give the engineer a practical priority to carry out the maintenance work in an efficient and orderly manner. This paper presents a rough set-based prototype system that aims at ranking the possible faults for fault diagnosis. The novel approach engages rough theory as a knowledge extraction tool to work on the past diagnostic records, which is registered in a pair-wise comparison table. It attempts to extract a set of minimal diagnostic rules encoding the preference pattern of decision making by domain experts. By means of the knowledge acquired, the ordering of possible faults for failure symptom can then be determined. The prototype system also incorporates a self-learning ability to accumulate the diagnostic knowledge. A case study is used to illustrate the functionality of the developed prototype. Result shows that the ranking outcome of the possible faults is reasonable and sensible. The fault diagnosis models systematically calculate the parameters based on RS. The results drawn from rough set based classification can be used for decision making. In the Pawlak model, one can have two types of rules, positive rules and boundary rules [5]. A positive rule indicates that an object or an object set for sure belongs to one decision class, which enables us to make a positive decision. A boundary rule indicates that an object or an object set partially belongs to the decision class, which leads to another type of decision. In a probabilistic rough set model, one can also have positive rules and boundary rules. A probabilistic positive rule expresses that an object or an object set belongs to one decision class beyond a certain confidence threshold. A probabilistic boundary rule expresses that an object or an object set belongs to one decision class beyond another weaker confidence threshold. Besides these two types of rules, there is another situation, such that one cannot indicate to which decision class the object or the object set belongs. Since the confidence is too low to support any decision making. The probabilistic positive and boundary rules can be distinguished not only by the syntax measures, such as confidence, coverage and generality, but also the semantics measures, such as decision-monotocity, cost and risk. The syntax properties focus on the discovery of the rules, while the semantics properties focus on the utilization of the rules, and thus are more practical for the real applications. Measures regarding the semantics properties are less studied in the rough set literature. The theory of rough sets has been applied to data analysis, data mining and knowledge discovery. A fundamental notion supporting such applications is the concept of attribute reduction [6]. The objective of reduct construction is to reduce the number of attributes, and at the same time, preserve a certain property that we want. For the Pawlak model, a single measure γ is suggested for evaluating the performance of classification and attribute reduction [7]. For a probabilistic model, by introducing the probabilistic thresholds, the properties are not necessarily monotonic with respect to the set inclusion, and cannot be evaluated by a single measure. Instead, we need to consider multiple properties and multiple measures for evaluation. More specifically, this paper addresses different criteria, such as confidence, coverage,
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generality, cost, and decision-monotocity criteria based on the decision-theoretic rough set models. Since the mid-1980s, a world-wide reform trend has transformed the institutional framework, organisation, and operating environment of the infrastructure and network industries including electricity. This has a substation model was developed to generate various fault scenarios for our case studies to evaluate the performance of the rough set algorithm.
2
The Pawlak Rough Set Model
In many data analysis applications, information and knowledge are stored and represented in an information table, where a set of objects are described by a set of attributes [8]. An information table represents all available information and knowledge. That is, objects are only perceived, observed, or measured by using a finite number of attributes. Papers not complying with the LNCS style will be reformatted. This can lead to an increase in the overall number of pages. We would therefore urge you not to squash your paper. Definition. An information table is the following tuple: S = (U , At , V , F ) where U is a finite nonempty set of objects, At is a finite nonempty set of attributes U = u1 , u 2 , , u n .A is a nonempty set of values of A = {a1, a2 , , a A } ,
{
}
At = C {D} , and U→a(U) is an information function that maps an object in U to
exactly one value in a( U ). In classification problems, we consider an information table of the form S = (U , A, V , F ) , where C is a set of condition attributes describing the objects, and D is a decision attribute that indicates the classes of objects. In general, we may have a set of decision attributes. A table with multiple decision attributes can be easily transformed into a table with a single decision attribute by considering the Cartesian product of the original decision attributes. The pair ( U , E A) is called an approximation space defined by the attribute set A. The
equivalence relation E A induces a partition of U, denoted by U E A . The equivalence class of U E A containing x is given by this
[x]EA = [x]A = { y ∈ U ( x, y) ∈ E A} , if
E A is understood. Consider an equivalence relation E on U. The equivalence classes induced by the partition U R , are the basic blocks to construct the Pawlak rough set approximations. For a subset X ∈ U, the lower and upper approximations of X with respect to U R are define by [22]: define R-lower approximation and R-upper approximation is: RX = {Y ∈ U
R
Y ⊆ X}.
(1)
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R X = {Y ∈ U
R
Y X ≠ φ} .
(2)
Based on the rough set approximations of X defined by R , one can divide the universe U into three disjoint regions: the positive region POS indicating the union of all the equivalence classes defined by R that each for sure can induce the decision class X; the boundary region bnR (X ) indicating the union of all the equivalence classes defined by R that each can induce a partial decision of X; and the negative region neg R which is the union of all equivalence classes that for sure cannot induce the decision class X [9-10]:
bnR ( X ) = R X − R X .
(3)
neg R ( X ) = U − R X .
(4)
R X = pos ( X ) bnR ( X ) .
(5)
An information table is consistent if each equivalence class defined by C decides a unique decision. In this case bnR (X ) = neg R (X ) ; and pos (x ) =U. An inconsistent information table contains at least one equivalence class U
R
∈ R such that it
associates with more than one decision.
3
A Rough Set Based Prototype System for Fault Diagnosis
Rough set theory has been widely used to handle classification problems (Slowinski,1993). In this work, a novel approach, which attempts to combine the strengths of rough set theory and the pair-wise comparison table suggested by Greco et al. (1995), is proposed. It aims at extracting a set of minimal diagnostic rules by learning from the historical records, which register the preferential decision pattern of the domain experts. In a typical fault diagnosis situation, the domain expert will suggest the maintenance work start from the most possible fault with the reference data acquired. Thus the nature of the fault diagnosis, which encoded specific preferential decision pattern, is close to a choice or ranking problem. In order to represent preferential information provided by the decision maker in form of a table comparison of the possible faults, a table is adopted here. The table is defined as a decision table. The data records are sets of exemplary table comparisons of reference actions (Greco et al., 1999), the decision attribute is the preferential information, which is provided by the domain expert, on the pair of the reference actions with the reference to the condition attributes. Thus, the elements of a table for fault diagnosis can be defined in the following manners:
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(1) The set of decision rules derived by the rough set approach gives a generalized description of knowledge contained in the financial information table, eliminating and redundancy typical for original data. (2) Rough set is a tool specifically suitable for analyzing not only quantitative attributes but also qualitative ones. (3) The decision rules obtained from the rough set approach are based on facts, because each decision rules is supported by a set of real examples. Take advantages of these characteristics as above, RS may be made to extract significant features from information to generate the decision rules for in fault diagnosis. This rough set-based approach can be illustrated using the engine diagnosis problem (Table 1). Assume that A is a finite set that contains the observed symptoms (O) of an engine malfunction on the universe of the performance of the engine, U, and A, Thus, each of the six observations can be associated with Attributes V(Vibration Level), T(Cooling Water Temperature) and W(Output Power). The equivalence relations between the machine performance and the symptoms of engine malfunction are given as follows: Table 1. Decision table of engine malfunction
O
V
T
W
F
1 2 3 4 5 6 7
Very high Very high High Normal High Normal Normal
Normal Normal High High Normal High High
Very low Low Low Low Normal Very low Normal
Y Y Y Y N N Y
Thus, each of the six observations can be associated with Attributes V, T and W. The equivalence relations between the machine performance and the symptoms of engine malfunction are given as follows: IND(A)={1,2,3,4,5,6,7}It can be readily shown that, IND(A-{V}) ≠ IND(A), IND(A-{T})=IND(A), IND(A-{W})=IND(A), Hence, V and W are indispensable in A. Since IND(V,W) ≠ IND(V) and IND(V,W) ≠ IND(W). The relations, V and W, are independent. Consequently, {V, W} is a reduct of A. As there is only one reduct of A, the core of A is also {V, W}, and is denoted as CORE(A). The reduct of A with respect to R={F} can be determined as follows. , , POS A ( R) = 1,2,3,4,5,6,7} POS A−{V } ( R ) = {1,2,5,6,7} ≠ POS A ( R )
POS A −{T } ( R) = {1,2,3,4,5,6,7} = POS A ( R) . Thus, T is R-discernible, whilst V and W are R-discernible, POS A −{W } ( R) = {1,2,3,5,} ≠ POS A ( R) .The R-core and Rreduct of A are both {V, W}. The superfluous elementary categories {T} can be
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eliminated from A, as the subset, {V, W}, can solely determine the classification of the object in relation to the elementary categories of Concept R. In fault diagnosis, by computing the relative core of the condition attributes in relation to the decision attribute, superfluous conditions can be removed from the original decision table without violating the final decision. By so doing, a minimal diagnostic rule set can be extracted. The results after deleting the redundant attribute, cooling water temperature (T), are shown in Table 2. Core value of each decision rule (each row in the decision table) is then calculated based on Table 2 and show as Table 3. Finally, the method adopted by Kusiak (2000) is used here to generate the value reduct for each of the rules. The final minimal rule set is shown in Table 4. Take Row 1 in the final decision table as an example, one of the five diagnostic rules in the minimal diagnostic rule set can be interpreted as follows: Rule 1: If the vibration level is very high then the engine is likely to be faulty. Thus, a compact and reasonable set of decision rules for fault diagnosis can be deduced from a set of observations. Table 2. Results of eliminating Attribute Cooling Water Temperature (T)
O 1 2 3 4 6 7
V
W
Very high Very high High Normal -----
----Low Low Very low Normal
F Y Y Y N Y N
Table 3. Results after the computation of the core values
O 1 2 3 4 6 7
V
W
Very high Very high High Normal -----
----Low Low Very low Normal
F Y Y Y N Y N
Table 4. Generation of the final minimal rule set
R 1 2 3 4
V
W
Very high High High ---
--Low Low Very high
F Y Y N Y
One of the important applications of rough set theory is to induce decision or classification rules. In this section, we consider two related issues. The first issue is
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the form and interpretation of rules. Two different types of classification rules are introduced and examined. The second issue is the evaluation of a single rule and a set of rules. The evaluation is investigated by considering the local evaluation of each single rule and the global evaluation of a set of rules.
4
Conclusion
To a real life maintenance task, the main concern of fault diagnosis is to provide the engineer with the information that in which order the components or the subassembly of the system should be checked to conduct efficient maintenance. In this work, a novel approach, which integrated the basic concepts of rough set theory for data analysis and pair-wise comparison table to transform a set of observed system performance data into a minimal diagnostic rule set, is presented. Based on this approach, a rough set-based prototype ranking system is developed. The proposed system has shown its strength in generating such an order of possible faults for the presented system failure efficiently with the input performance data. The diagnosis process with a simplified pump system is used as a case study to illustrate the effectiveness of the prototype system. Result shows that a logical and sensible ordering of the possible faults can be easily obtained with the reference to the generated minimal rule set. This has demonstrated that the proposed approach provides an avenue to extract the decision pattern of the diagnosis expert, which is based on their accumulated knowledge and experience of the domain. Furthermore, by interviewing the domain experts with the preferential information about the new diagnosis case, the prototype system also possesses a self-learning capability to accumulate the knowledge and grow the induced rule base to ensure its effectiveness on all the possible diagnosis situations. To further validate and improve the approach, comparative study with similar case studies done by other ranking approach is planned in near future. Equipped by this prototype system, it can be anticipated that the maintenance engineer in a manufacturing plant will be able to carry out fault diagnosis in a more efficient and orderly manner.
References 1. Smith, T.F., Waterman, M.S.: Identification of Common Molecular Subsequences. J. Mol. Biol. 147, 195–197 (1981) 2. May, P., Ehrlich, H.-C., Steinke, T.: ZIB Structure Prediction Pipeline: Composing a Complex Biological Workflow Through Web Services. In: Nagel, W.E., Walter, W.V., Lehner, W. (eds.) Euro-Par 2006. LNCS, vol. 4128, pp. 1148–1158. Springer, Heidelberg (2006) 3. Foster, I., Kesselman, C.: The Grid: Blueprint for a New Computing Infrastructure. Morgan Kaufmann, San Francisco (1999) 4. Czajkowski, K., Fitzgerald, S., Foster, I., Kesselman, C.: Grid Information Services for Distributed Resource Sharing. In: 10th IEEE International Symposium on High Performance Distributed Computing, pp. 181–184. IEEE Press, New York (2001)
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5. Foster, I., Kesselman, C., Nick, J., Tuecke, S.: The Physiology of the Grid: an Open Grid Services Architecture for Distributed Systems Integration. Technical report, Global Grid Forum (2002) 6. Wang, C., Jia, Q.Q., Li, X.B., Dou, C.X.: Fault location using synchronized sequence measurements. Int. J. Elect. Power Energy Syst. 30(2), 134–139 (2008) 7. Jung, H., Park, Y., Han, M., Lee, C., Park, H., Shin, M.: Novel technique for fault location estimation on parallel transmission lines using wavelet. Int. J. Elect. Power Energy Syst. 29(1), 76–82 (2007) 8. Yan, B.Y., Tian, Z.H., Shi, S.J.: A novel distributed approach to robust fault detection and identification. Int. J. Elect. Power Energy Syst. 30(5), 343–360 (2008) 9. Safty, S.E., El-Zonkoly, A.: Applying wavelet entropy principle in fault classification. Int. J. Elect. Power Energy Syst. 31(10), 604–607 (2009) 10. Geng, Z., Zhu, Q.: Rough set-based heuristic hybrid recognizer and its application in fault diagnosis. Expert Systems with Applications, 2711–2718 (2009) 11. Yao, Y., Zhao, Y.: Attribute reduction in decision-theoretic rough set models, Canada (2009) 12. Yao, Y.: Decision-theoretic Rough Set Models. In: Yao, J., Lingras, P., Wu, W.-Z., Szczuka, M.S., Cercone, N.J., Ślȩzak, D. (eds.) RSKT 2007. LNCS (LNAI), vol. 4481, pp. 1–12. Springer, Heidelberg (2007) 13. Pawlak, Z.: Rough sets. International Journal of Computer and Information Sciences 11, 341–356 (1982) 14. Wang, Q.H., Li, J.R.: A rough set-based fault ranking prototype system for fault diagnosis. Engineering Applications of Artificial Intelligence 17, 909–917 (2004) 15. Kryszkiewicz, M.: Rules in incomplete information systems. Information Sciences 113, 271–292 (1999)
Synchronization of Uncertain Chaotic Systems with Different Structure in Driven and Response Systems Junwei Lei1,* Aiqiang Xu2, Yuliang Chen3, and Guoqiang Liang1 1
Department of Control Engineering, Naval Aeronautical and Astronautical University, 264001 Yantai, China 2 Department of Scientific Research, Naval Aeronautical and Astronautical University, 264001 Yantai, China 3 Department of Ordnance Science and Technology, Naval Aeronautical and Astronautical University, 264001 Yantai, China {leijunwei,xuaiqiang1024,chengyuliang1024, liangguoqiang1024}@126.com
Abstract. Considering the situation that the driven system and the response system have different structure and different order, a kind of double integral sliding mode surface is proposed based on the previous PI type sliding mode method. The sliding mode control and adaptive control strategy are integrated to solve the completely unknown parameters and uncertain nonlinear functions. Finally, a double integrators adaptive sliding mode controller is proposed to solve the synchronization problem of a large family of uncertain chaotic system. Keywords: Chaos, Uncertainty, synchronization, Unknown parameter, Control.
1
Introduction
It was widely studied by researchers for the situation that the chaotic system has the same structure between driven and response system. And it is not easy to accept the phenomenon that chaotic systems with different structure and even different order can synchronize. Ming-Chung Ho researched the synchronization problem between a four dimension Lorenz chaotic system and three dimension Lv system. But he only considered the situation of uncertain parameters and other kinds of uncertainties such as unknown nonlinear function was not concerned. Tsung-Ying Chiang designed a sliding mode adaptive controller to synchronize a kind of uniformed chaotic system based on Lyapunov function theorem and PI type sliding mode method. The nonlinear function situation was considered and a linear bound is necessary to be known. It is easy to analyze the stability of the whole system with the sliding mode strategy but it is difficult to apply this method to a general kind of systems because the sliding surface is skillfully constructed for the special system. In this paper, considering the situation that the driven system and the response system have different structure and different order, a kind of double integral sliding *
mode surface is proposed based on the previous PI type sliding mode method. The sliding mode control and adaptive control strategy are integrated to solve the completely unknown parameters and uncertain nonlinear functions. Finally, a double integrators adaptive sliding mode controller is proposed to solve the synchronization problem of a large family of uncertain chaotic system.
2
Problem Description
Consider the below driven system and response system, the response system has unknown parameters and uncertain nonlinear function, the structure of driven system is different from the response system. Without loss of generity, assume the dimension of dirven system is higher than response system, and the dimension of driven system is n+r, and the dimension of response system is r. The structure of driven system can be written as follow.
x p = f p x ( x ) + F p x ( x )θ p x + Δ p x ( x , t )
(1)
.
The else R dimension driven system can be written as
x r = f rx ( x ) + F rx ( x )θ r x + Δ rx ( x , t )
(2)
The response system can be written as
y = f y ( y ) + Fy ( y )θ y + Δ y ( y, t ) + bu
(3)
Take the follow situation as an example, the dimension of driven system is four and the dimension of response system is three and they can be expanded as follows. For the main driven system, it can be written as p1
p2
j =1
j =1
p1
p2
j =1
j =1
x p1 = f px1 ( x p1 , x p 2 , x p 3 , xr1 ) + Fpx1 j ( x p1 , x p 2 , x p 3 , xr1 )θ px1 j + Δ px1 j ( x, t )
(4)
And x p 2 = f px 2 ( x p1 , x p 2 , x p 3 , xr1 ) + Fpx 2 j ( x p1 , x p 2 , x p 3 , xr1 )θ px 2 j + Δ pxij ( x, t )
(5)
Also p1
p2
j =1
j =1
x p 3 = f px 3 ( x p1 , x p 2 , x p 3 , xr1 ) + Fpx 3 j ( x p1 , x p 2 , x p 3 , xr1 )θ px 3 j + Δ px 2 j ( x, t )
For the else R dimension driven system, it can be described as
(6)
Synchronization of Uncertain Chaotic Systems with Different Structure
p1
p2
j =1
j =1
xr1 = f rx1 ( x p1 , x p 2 , x p 3 , xr1 ) + Frx1 j ( x p1 , x p 2 , x p 3 , xr1 )θ rx1 j + Δ rx1 j ( x, t )
y 2 = f y 2 ( y1 , , y4 ) + Fy 2 j ( y1 , , y4 )θ y 2 j + Δ y 2 j ( y, t ) + b2u2
y3 = f y 3 ( y1 ,, y4 ) + Fy 3 j ( y1 ,, y4 )θ y1 j + Δ y 3 j ( y, t ) + b3u3 Then
θx , θ y
(8)
(9)
(10)
are unknown parameters. The control objective is to design a
u = u ( x, y,θˆpx , qˆ px ,θˆy , qˆ y ) , θˆpx = f ( x, y, θˆpx ) , qˆ px = f ( x, y, qˆ px ) , θˆy = f ( x, y, θˆy ) , qˆ y = f ( x, y, qˆ y ) such that the Synchronization of state can be achieved, it means that y → x . synchronization
3
law
Assumptions
It is necessary to give the following typical assumptions to make the analysis of the system more convenient. Assumption 1: All the states of driven system and response system are measurable. Assumption 2: The driven system and response system have the same structure and it means that they also have the same dimension and
Fxij , f xi is known.
Assumption 3: The structure of some part of the driven system is known, it means
Fyij , f yi , bi is known. Assumption 4: The structure of some part of the response system is known, it means
Fyij , f yi , bi is known. Assumption 5: The nonlinear functions of driven system satisfies the follow conditions such as there exists a unknown positive parameters for 1 ≤ i ≤ n , 1 ≤
q*pxij ≤ d pxij such that
j ≤ p2 , it holds Δ pxij ( X , t ) ≤ q*pxijψ pxij ( X )
(11)
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Where
d pxij is a known constant and ψ pxij ( X ) is known smooth and non-negative
function. Assumption 6: The nonlinear functions of response system satisfies the follow conditions such as there exists a unknown positive parameters for
q*yij ≤ d yij such that
1 ≤ i ≤ n , 1 ≤ j ≤ p4 , it holds Δ yij ( X , t ) ≤ q*yijψ yij ( X )
Where
(12)
d yij is a known constant and ψ yij ( X ) is known smooth and non-negative
function.
4
Design of Double Integrator Sliding Mode Synchronization Controller
Define a new variable as zi = yi − xi for the above driven and response system and the error system can be written as p3
p4
j =1
j =1
zi = f yi ( y1,, y4 ) − f pxi (x1,, x4 ) + Fyij ( y1,, y4 )θyij + Δyij ( y, t) p1
p2
j =1
j =1
. (13)
−Fpxij (x1,, x4 )θ pxij − Δpxij (x, t) + bu i i Define the sliding mode as t
t
0
0 0
si = zi + asi zi dt + bsi
t
zi dtdt
(14)
Solve the derivative of the sliding mode as t
si = zi + asi zi + bsi zi dt = f yi ( y1 ,, y4 ) − f pxi ( x1 , , x4 ) 0
1 2 n p2 1 V = s + (θ pxij ) + ( qij ) 2 . i =1 i =1 j =1 2 i =1 j =1 2 n
n
2 i
p1
(31)
It is easy to prove that n
V ≤ − si f si ( si ) ≤ 0 .
(32)
i =1
So the synchronization problem of chaotic system with different structures are solved.
5
Conclusions
A double integrator type sliding mode is firstly proposed in this paper to solve the synchronization of chaotic systems with different structure and different dimension in driven system and response system. Also by constructing a Lyapunov function, the unknown parameters problem and uncertain nonlinear functions are solved by introducing a robust and adaptive strategy in the design of synchronization controller.
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References 1. Chiang, T.-Y., Lin, J.-S., Liao, T.-L., Yan, J.-J.: Antisynchronization of uncertain unified chaotic systems with dead-zone nonlinearity. Nonlinear Analysis 68, 2629–2637 (2008); Physics Letters A 350, 36–43 (2006) 2. Wang, B.: Robust adaptive control of uncertain general low triangular nonlinear system and its application in electronic systems, [Ph. D. Thesis]. China University of Science and Technology (2006) 3. Gang, C.: Research on robust adaptive control of uncertain nonlinear system, [Ph.D.Thesis], Zhejing University (2006) 4. Ge, S.S., Wang, C.: Adaptive control of uncertain chus’s circuits. IEEE Trans. Circuits System 47(9), 1397–1402 (2000) 5. Fradkov, A.L., Yu, M.A.: Adaptive synchronization of chaotic systems based on speed gradient method and passification. IEEE Trans. Circuits System 44(10), 905–912 (1997) 6. Dong, X., Chen, L.: Adaptive control of the uncertain Duffing oscillator. Int. J. Bifurcation and chaos 7(7), 1651–1658 (1997) 7. Tao, Y., Yang, C.-M., Yang, L.-B.: A Detailed Study of Adaptive Control of Chaotic Systems with Unknown Parameters. Dynamics and Control (8), 255–267 (1998) 8. Lei, J., Wang, X., Lei, Y.: How many parameters can be identified by adaptive synchronization in chaotic systems? Physics Letters A 373(14), 1249–1256 (2009) 9. Lei, J., Wang, X., Lei, Y.: A Nussbaum gain adaptive synchronization of a new hyperchaotic system with input uncertainties and unknown parameters. Communications in Nonlinear Science and Numerical Simulation 14(8), 3439–3448 (2009) 10. Wang, X., Lei, J., Lei, Y.: Trigonometric RBF Neural Robust Controller Design for a Class of Nonlinear System with Linear Input Unmodeled Dynamics. Applied Mathmatical and Computation 185, 989–1002 (2007) 11. Wang, X., Wang, H., Lei, H., Lei, J.: Stable Robust Control for Chaotic Systems Based on Linear-paremeter-neural-networks. In: The 2nd International Conference on Natural Computation (ICNC 2006) and the 3rd International Conference on Fuzzy Systems and Knowledge Discovery (FSKD 2006), Xian, China, September 24-28 (2006)
Study on Innovative Culture Construction in Newly Established Local Undergraduate Course Academies Yanchun Shen, Yinpu Zhang, and Zhihua Hao College of Tangshan, Tangshan, Heibei, China {Yanchun Shen,Yinpu Zhang,Zhihua Hao,cnsyc}@126.com
Abstract. Innovative culture is the engine of university innovation. Newly established local undergraduate course academies shoulder the dual responsibilities of nurturing application talents and serving the social development of local economy. How to fabricate pluralistic university culture in the process of development, and how to stimulate the inner momentum of university culture innovation, have become problems that demand immediate solution. Keywords: Innovative Culture, Application Style Talents, Local Undergraduate Course Academies, University Culture.
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Introduction
In the five-year round undergraduate course evaluation by the Department of Education, university culture is regarded as part of the evaluation contents. As the footstone for university development, university culture is the soul of the university. Given that newly established local undergraduate course academies are mostly newly founded, or incorporated, evident insufficiencies lie in terms of operation concept, experience, level, and feature, among most of them. Hence, culture construction will exert unique function in carrying on, integrating, and absorbing operation culture of the originals universities, and forming its own culture.
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Contents of University Culture and Innovation Culture
activities. It is a comprehensive integration of value concept, code of conduct, and social environment beneficial to innovative activities. As the core feature of university culture, university innovative culture not only influences the thoughts and behaviors of teachers and students in university, but also penetrates and various aspects in university. It is of significant meaning to the formation of university development, talent nurturance, and university spirit. University culture is a comprehensive concept. It is a group culture which centers the university as the geographic space, the teachers and students as the activity main body, and the spirit of the university as soul. University culture and local culture are inter-dependent. Local culture is the basis and platform of the construction of university culture, while university culture that formed by newly established local undergraduate course academies radiates and influence the construction and development of local culture.
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The Importance of University Culture Construction
The construction of university culture, is beneficial to the forming of core competitiveness, and the nurturing of innovative spirit and ability of the teachers and students. It is the footstone of the existence and development of university, and reflected in below. 3.1
University is the Core Competitiveness of the University
The core competitiveness of a university refers to the competitive edge formed in the process of long term operation, possessed by the university only, which brings value to the university, supports the past, present, and future of the university. It is the core ability that enables the university to obtained active and sustainable growth for a long period of time within the inner competitive environment. [3] The core competitiveness of a university is reflected in five aspects, students, scholars, courses, science, and style of study. Students, the main body of education, play a significant role in the forming of university culture. The carry-on and development of university culture, to a certain large degree, is determined by the shaping of students self cultural awareness. Scholars are the important guarantee of university core competitiveness. The character, personality, and knowledge of scholars have huge impact on the extensiveness and profoundness of university culture. Courses are the medium of university culture, an important component of university core competitiveness. The conscious and unconscious penetration, into teachers and students, via courses culture, forms unique cultural atmosphere of the university. Science represents the level of teaching and scientific research of the university. Academic results are the collective embodiment of university core competitiveness. Style of study, is another collective embodiment of university culture. A good style of study, depends on the individual attainment of teachers and students, and impacts on the individuals as well.
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Innovative Ability Is the Drive of the Forming of University Core Competitiveness
Innovation is the inner momentum of university development. It is a behavior activity, generated by the main body for societal needs, based on things intrinsic. It possesses the potential to impel social development, the feature of frontier, value, and surpassing results. [4] Innovative university culture, refers to the unique university culture with teachers and students as innovative medium, the nurture of innovative spirit, ability, and way of thinking as standpoint, and formed via the construction of spiritual culture, material culture, and system culture. It is one of the key factors in university core competitiveness. Highly effective scientific management system, formed by innovative scientific organization and management system mechanism, enables the scientific and research ability of the university to shape composition of forces, and increase investment in key scientific research field. Innovative scientific policy environment and innovative culture atmosphere, encourage the culture atmosphere of daring to explore, and tolerance of failure; strengthen education on integrity and professional ethics; nurture practical, realistic, and rigid scientific spirit. Concentrate on the unification of scientific research and education. The mission of university is the nurture of talents. [5]The nurture of innovative talents is the embodiment of university innovative ability. The supporting function of science and research to teaching is reflected on the impartment of knowledge by the teachers to the students. Reinforce the amalgamation of cross disciplines, foster new course increase point, construct diversified cross discipline scientific and research system via cross disciplines, and enhance originality and ability of integrate. 3.3
University Culture is the Footstone of University Development
University culture includes three layers, spiritual culture, material culture, and system culture. Spiritual culture is the soul of university. [6] It is the resemblance of university personality and style, the “soft strength” of university culture. Material culture is the material base of university, the “hard strength” of university culture. [7]System culture is the code of conduct of university operation. It ensures the sequential implementation of various university activities.
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Newly Established Local Undergraduate Course Academies Lack in Innovative Culture Construction
As newly established local undergraduate course academies fall short in operation concept and feature when compared with old brand universities, it constrains its development of innovative culture. This is presented in the following aspects. 4.1
Urgent Need for the Forming of University Spiritual Culture
The university spirit of a university is formed in the process of long term operation. [8] As newly established local undergraduate course academies are mostly combined
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by associate level for undergraduate degree, or several schools, the operation concept and mode are dissimilar. Common believe, system, and concept of value need to be formed during the process of grinding. This constrains university development to certain degree. 4.2
Improvement in University Material Culture Needed
Given the historical reasons, newly established local undergraduate course academies normally have limited and scattered campus space. Financial pressure is weighing on in the preliminary stage of construction. There is lack of teaching staff, and unsound professional degree structure, degrees and titles. [9]University innovation is closely related to its knowledge storage and talent quality. The lack of university material culture, without doubt, has negative impact on the forming of university innovative culture. 4.3
Lagging behind University System Culture Construction
Before the new university is incorporated, each university has its own management system. After the incorporation, these dissimilar systems conflict with each other. The operation positioning, and concept of development for the newly established local undergraduate course academies are not yet shaped. Thus, the system is lagging behind. And in turn, it impacts on the forming of university culture. On the other hand, if the constrain function of the system is over-emphasized, the lack of peopleoriented approach drags down the forming of innovative culture. [10]
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Relationship between Innovative Culture and Local Culture in Local Undergraduate Course Academies
Footing on serving local development and construction, it is inevitable that when forming its own university culture, local undergraduate course academies are bound to be influenced, referenced, and dependant on local culture. [11]The forming of university innovative culture can not be separated from local culture. This is embodies in the following aspects. 5.1
University Culture is the Accumulation and Crystal of Local Culture
Local undergraduate course academies are located in local area, to serve the development of local economy and society. It is absorbed in local culture. [12]And its culture takes root and grows in the inter-exchange among university, industry, and society. Rich local culture provides broad space for cultural heritage and development of local undergraduate course academies. It is the background and platform for the construction of university innovative culture, the soil for the existence and development of local universities.
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University Culture is the Beacon and Leader in Local Culture
University is an educational institute, as well as a cultural institute. It is the leader and foremost drive for the construction of local culture. Via the studying local culture, dialectically analyzing local culture, university can then lead local culture. University culture is hidden in university, and spreading beyond university. Culture created in university is not limited within the boarders of university. It has become the advanced culture that can lead the society. [1] In America, there is a saying that “First came Harvard, and then America”. In Germany, the famous Berlin Humboldt University created the splendid culture for Germany. Hegel, Feuerbach, the great thinkers who promoted the progression of history, once studied or taught in this university.[13]
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Thoughts on the Construction of Innovation Culture of Newly Established Local Undergraduate Course Academies
The fundamental mission of newly established local undergraduate course academies is, footing on local, nurturing high quality comprehensive development high level talents, serving local economic and societal development. Constructing university innovative culture is on the immediate agenda for integrating and optimizing educational resources, enhancing operation level and education quality, and upgrading university culture contents. 6.1
Wake Up Cultural Awareness, Raise Cultural Consciousness
Fei Xiaotong points out that, cultural awareness refers to giving sufficient attention to the function of culture, on the basis of clearly understanding human culture and university culture, wake up the consciousness for self development, to select, carry on, and innovate scientific and researchable culture, and engender the inner need for university culture construction, and continuously uplift potential for self development. [2]This requires that, every main body of a university, regardless teachers or students, everyone should have sufficient recognition on the importance of cultural construction for university, and devote in personal dedication to implement in reality, and thus form huge spiritual force, and become drive for university innovative culture. 6.2
The fundamental task of universities is to educate people, further perfect innovative system, with people development as the essence, reform the talent nurture mode from singular to complex and multilateral conversion. Break the singular teaching culture, construct teaching mode with nurture objective as main body, societal needs as guidance. Combine university innovation with market. Hold innovation as the principle line, establish financial management, human resource allocation, reward and punishment system with incentive as drive. Encourage innovative system guarantee, respect the main body feature of people. The design of system should reflect more
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with people orientation. Encourage innovation, and be tolerant to failure. Create a flexible systemic environment. 6.3
Increase Investment in Innovation, Reinforce Material Guarantee
The process of innovation, is a process of continuous exploration. Universities should increase investment in innovation, path solid foundation for innovative teaching. Initiate innovative activeness of the teachers and students, and offer conditions for students to implement innovative practice, by means of opening innovative education course, constructing innovative practice site, promoting tutor system, etc.. Encourage the students to apply for invention patent, promote results conversion, strengthen students’ ability to innovate, initiate entrepreneurship, and find jobs.
References 1. Xu, Q.: University Culture and University Spirit. Journal of Tianzhong 21(6), 119–120 (2006) 2. Ming, L., Zhang, X.: Newly problems in the construction of innovation culture and Countermeasures. Journal of Yunnan Finance & Economics University 25(3), 128–130 (2010) 3. Shi, L.: University Culture and the University Core Competence. Journal of Yancheng Institute of Technology 23(4), 67–70 (2010) 4. Zhang, S., Zhang, Z.: Core Factors of Core Competitiveness in University. Journal of Shanxi College for Youth Administrato 19(4), 93–95 (2006) 5. Wu, S.: Innovation and personnel training of university reform and innovation of mechanism. Innovation 33(5), 115–117 (2011) 6. Zhang, Z.: Innovative Training Model. CO-Operative Economy & Science 419(6), 116– 117 (2011) 7. Xiao, H., Zhang, S., Deng, S.: China’s Innovative Thinking Training. Contemporary Education Forum (5), 58–60 (2011) 8. Chen, X.: International comparison of innovative talents’cultivation of higher education and the implications. Journal of Chongqing Education College 24(2), 128–131 (2011) 9. Cheng, P., Peng, Y., Wang, H.: Of our colleges and universities more innovative training model Pondering. Science and Technology Innovation Herald 9, 142–143 (2011) 10. Chen, T.: Colleges and universities to enhance education on innovation and thinking. Journal of Zhoukou Normal University 28(1), 116–117 (2011) 11. Zou, F., Yu, L.: Innovative Education for the current problems facing the thinking. Education for Chinese After-school 12, 14 (2010) 12. Gao, Z., Kang, J.: Colleges and universities to explore innovative training model. Tribune of Social Sciences 24, 179–182 (2010) 13. Zhang, X., Wang, H., Lv, Y.: Local colleges and universities innovative training model reform strategy. China University Teaching 33(5), 115–117 (2011)
The Problems of Work Placements in Application-Oriented Undergraduate Colleges and Its Countermeasure Research Yanchun Shen*, Yinpu Zhang, and Minglin Yao College of Tangshan, Tangshan, Heibei, China {Yanchun Shen,Yinpu Zhang,Minglin Yao,cnsyc}@126.com
Abstract. Application-oriented undergraduate colleges are usually newly-built local academies, whose central task is to make contributions to the local economy and social development. Work placement is an indispensable process for application-oriented undergraduate colleges basing themselves on applying talents training. In this paper, the author expounds and analyzes the difficulties and problems in enterprises, colleges and students during the process of work placements. Countermeasures and suggestions are given from such three perspectives as of the nation, enterprises and colleges. Keywords: application-oriented undergraduate colleges, newly-built local academies, applying talent, work placement.
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Policy Basis of Work Placement and Its Development in China and Abroad
Tertiary Education [2006]16 has stipulated explicitly:” Active implement ordereducation; explore teaching methods such as work-study alternation, task-driving, case teaching and work placement to build up students’ abilities; induct the enterprises to build up the system of receiving work placements of higher vocation technical students; strength the students’ productive and social practice; higher vocational colleges should ensure the students go to enterprises for work placements at least half a year.” [1] The new national strategy Development Plan Outline for Medium and Long Term Educational Reform and Development points out that, vocational education should face everybody and the society, should be further improve the students’ professional morality, vocational skills, employability and the ability to initiate. Vocational education should build a new cultivating mode for talents with work-study combination, enterprise-college cooperation and work placements. Vocational education should establish and improve vocational education quality assurance system and invite enterprises to attend education quality assessment. [2] *
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Since 1990s, America government has introduced a package of measures of fiscal subsidies and tax reduction to encourage enterprise-college cooperation in talents training. In Germany, where vocational education is highly developed, employer federation, labor union and teachers from vocational schools combine to profession associations and assess the quality of dual system vocational education. In recent years, China encourages the combination of higher education and enterprises in order to develop high-quality application oriented talents. The cooperation between academics and enterprises could help enterprises find out the excellent employee and guarantee the sustainable development of enterprises.
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The Connotation and Significance of Work Placement
1) The Connotation of Work Placement Work placement refers that, after students finished their core courses, specialized courses and in-school specialized practices, the students could study and work in production line undergoing productive labor just like many other professional workers in some real working positions and situations. They act as students and workers. Colleges make full use of enterprises’ HR resource, technology, equipments and business environment. Through enterprise-college cooperation, students’ job specific skills, social ability, manner ability and innovative ability are improved during the process of work placements under the lead of skilled master in enterprise environment. Students’ professional quality and competition ability can be promoted so as to shorten their new occupational suiting period. This method can achieve the training aim that graduation means employment, employment means taking up the post and taking up the post means work placement. [3] 2) The Significance of Work Placement Work placement is not only beneficial to students’ professional quality but also advantageous for students knowing the society in advance. As an important part of education combining learning and production, work placement can strengthen post consciousness and responsibility and extremely improve students’ comprehensive quality. The significance has manifested mainly in the spheres as follows: First, work placement is an effective ways for colleges making full use of social educational resource to run well higher vocational education. Colleges and enterprise will jointly decide the criteria of talent training and cultivate students working capability and comprehensive quality, which could improve the quality of talents cultivation and achieve the aim of talent cultivation in higher vocational colleges. Second, work placement can optimize teaching force structure and enlarge teaching forces. On the one hand the college selects and appoints some experienced part-time advisors; on the other hand the teachers go down to enterprises and gain practical experience, which can build up double-quality teachers and improve teaching effects. Third, work placement spurs enterprises to have a number of high-tech, high quality and stable labors, which could recruit technical forces and solve the problem of talent shortage, as well as enrich enterprise culture and increase economic efficiency. Fourth, work placement can spur students to integrate theory with practice, enrich their work
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experience and lay the groundwork for future employment. Therefore, the aim of work placement is that, “let the students start a new job with work experience”. Fifth, work placement can improve communication skill and adaptive capacity of the students, which greatly improves their Interpersonal competence. [3,4,5] Work placement is an important part of education combining learning and production and is the concrete embodiment of enterprise-college cooperation and work-study combination. Through professional job and vocational training, the students improve their recognitions of professional society and obtain some information about their future occupations. The students can get some experience on how to deal with boss and colleague and how to do teamwork during this process. [6-9]
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The Problems in Students’ Work Placements
The problems existed in work placement which is done by the enterprise, the college and students are manifested in the following points: 1) It is difficult to find the internship enterprise Numerous students have to attend to work placement in a concentration time, while enterprises’ the demand for labor is fluctuated with orders. This creates the problem that college work placement doesn’t attuned to the demands of enterprises. The graduates who are freshly out of school still need to improve their professional ability and quality and there are safety risks existed in production, which cause that poorly motivated cooperative enterprise wouldn’t like to attend. 2) The inconsistency between the aim of enterprise and college Some productive enterprises accept work placement due to their heavy backlog and the lack of labor. In order to ensure safety in production of work placement, the enterprise hope the students engage in repetitive work of lower science and technology. However, the students want to learn knowledge from their work placements. The aim of colleges’ student cultivation is not accordance with that of enterprises’ production task accomplishment, resulting in reduced effect of work placement. 3) Non-equivalences between school management and enterprise management Students are dispersed in different production links and the teachers can’t effectively control each student during their work placements. The masters in production line bearing production pressure usually pay little attention to these students. This results in student management and evaluation work lagging behind. Students are used to the management system of school and show faulty adaptation on management mode of enterprises. 4) Different evaluation criterions between colleges and enterprises Enterprises aim at products while colleges aim at education. Different aims result in different evaluation criterions. Enterprises’ evaluations to students are usually limited to product quality, while colleges’ evaluations to students usually focus on learning efficiency. How to cooperate with enterprises and how to evaluate the effect of
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students work placements are special consideration during the process of work placement. [10,11] 5) Students are not used to role transition Staying in school for many years, students have been used to teachers’ management mode. In enterprises, the management mode of the master is different from school. Colleague relationship replace of close teacher-student relationship and fellowship, which can’t be easily adapted by the students going out into the society. 6) The management problems existed in decentralized work placements[12] Due to work placement in a concentration time, enterprises only can provide limited jobs which result that students are dispersed into different enterprises. Different enterprises have different transportation and working hours. Therefore, limited teachers can lead to poor instructions. 7) Lack of effective process control and assessment/evaluation system These negative effects have manifested themselves mainly in the spheres as follows: achievement evaluations are without the participation of enterprise supervisor. Therefore, the internship situation of the students can’t be recorded exactly. The examination usually takes report as its only one form, which can’t reflect students’ real effects on work placements. The supervision and evaluation system is not perfect and the range of supervision and evaluation is limited. [13-15]
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Some Suggestions on Improving the Effect of Work Placement
4.1
Nation Level
The government should formulate policies and preferential measures to raise enterprise enthusiasm of professional skill training. Practice activities which are benefit to improve whole national work skills, such as Work placement, should be promoted from the view of strategy. The organizations that can promote collegeenterprise cooperation should be set up in different provinces, cities and regions to coordinate the cooperation between colleges and enterprises. 4.2
Enterprise Level
The impulsive force of high-quality talent to enterprise development should be full realized. The effect of work placement on enterprise development should be viewed from long-term perspective and based on enterprise development strategy. Actively cooperate with college to establish the project of work placement. It is imperative to participate into the management and evaluation of work placement. The perfect system of college-enterprise cooperation should be established to ensure the stability of enterprise reserve talent[16].
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College Level
More attention should be paid to work placement. Cooperation organization should be set up in American manner. The organization is special responsible for contacting with internship enterprise, coordinating negotiation and contract signing between colleges and enterprises. It instructs students how to choose internship enterprise according to personal interests. Works shall be done from the following respects [17,18] 1) Perfect management system. Fine management should be realized according to strengthen cooperation between colleges and enterprises. Management system of work placement should be further improved and implemented on every links and ever the whole process. There will be rules to go by in every link related to organization, education and supervision. Both teachers and technical personnel judge the achievement evaluation of the students, which can reflect students’ real internship achievements. 2) Cooperative school-running. The second-rank college is co-invested by the enterprise and the college and its incomes are shared by both parties. This kind of college not only brings out appropriate talent for enterprises but also improves teaching body and managerial condition, which make the study more practical and is benefit for students to get job opportunities. [19] 3) Develop professional practice base in various ways. Work placement should be systemized and normalized in the practice bases with the huge demand of talent, which is beneficial for colleges and enterprises to summarize experience and develop suitable talents and is also helpful for students to improve the effect of their work placements. 4) Joint develop practical training laboratory. Besides work placement outside colleges, the resources in colleges can be full used to provide convenience to students. Practical training lab can be developed by colleges and enterprises. [20,21] 5) Cultivating to order. Cooperated with enterprises or industries, colleges can found up some classes cultivating to order and establish cultivation project together with enterprises. The college is responsible for theory teaching and providing study sites. The enterprise is responsible for equipments and engineering technical staff. The students in ordered class aim at the demand of enterprises. Students can soon shake down the new post after graduation. 6) Perfect incentive mechanism. According to evaluate excellent intern and teachers, incite teachers and students to attach greater importance to work placement. Take them as fine examples. In this way, work placement could promote teaching and practice. 7) Optimize subject set-up. Through work placement, students can learn more knowledge and skills about production line and teachers can pay more attention on the combination of theory and practice. The reform drives innovative teaching, further optimize subject set-up and improve the quality of teaching.
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Summary
Work placement is teaching basic norm which can promote applied talent to be professional and realize a close relationship between practice & training site and professional work situation. Work placement is an important part of education in newly-built applied colleges which contribute to cultivate skilled talents adapted to the front line of production, contribution, service and management. Enhance process control and quality assessment of work placement is an important act for deepening education reform, strengthening connotation construction and elevating the quality of talents cultivation. It is also an important content of reform in talent cultivation of promotes college-enterprise cooperation and work-study combination. It is of great significance to improve the quality of applied talents in our nation. [3]
References 1. Ministry of Education. On the overall teaching quality of higher vocational education to improve a number of views, 16 (2006) 2. National long-term development plan and reform for education (2010-2020) (July 2010) 3. Xu, X.: Students in vocational colleges during post practice of monitoring and evaluation system. Career Horizon 7(2), 33–35 (2011) 4. Wang, Z.-s.: On the Practice of the Management of Post Training. Vocational And Technical Education 32(5), 66–68 (2011) 5. Liu, Y., Wang, Y., Wang, Z.: Thoughts on Preparation of Workplacements Internship. Value Engineering, 289 (2011) 6. Zhou, S.: Internships for students in vocational colleges of quality control. Education (1), 165–167 (2011) 7. Wang, X.: Higher vocational school teachers Dinggang Practice. Journal of Vocational and Technical Education (1), 71–72 (2011) 8. Zhang, L., Xie, X., Chen, T.: Vocational students to explore internships and practice management. Cumulatively 138(2), 133–134 (2011) 9. Chen, J.: Based on China’s national conditions of work and study the implementation of Training Mode Choice. China Higher Education Research 7, 52–54 (2007) 10. Wu, R.: Vocational internships during the refinement of management. Jinhua Vocational and Technical College 10(6), 5–7 (2010) 11. Zhang, Y., Cheng, J.: Vocational student internships in research and evaluation system implemented Practice. China’s Vocational and Technical Education (5) (2008) 12. Xu, X.: Vocational student internships process monitoring and evaluation system. Career Horizon 7(2), 33–35 (2011) 13. Wang, X., Wang, L., Li, X.: Cooperative Education: the importance of applicationoriented training purposes Diameter. Modern Education, Science (5), 173–175 (2010) 14. Guo, W.: School-enterprise integration — towards win-win industry-university cooperative education model innovation bases And practice. Beijing Education (1), 12–14 (2010) 15. Zhang, Y.: Into the military. Vocational student internships evaluation system of research and practice. Chinese Occupation Technical Education (5), 10–11 (2008) 16. Chen, X.: International comparison of innovative talents’cultivation of higher education and the implications. Journal of Chongqing Education College 24(2), 128–131 (2011)
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17. Zhang, L., Jing, Y.: Exploration and Experience of Arrangement and Management Mode in Post Practice of Students Majoring in Economics and Management. Value Engineering 33(5), 247–248 (2011) 18. Xia, L., Wang, G.: On the vocational graduates internships new features. Promote Employability 12, 24 (2010) 19. Su, J.: Vocational education, school-enterprise cooperation in the study of practice. East China Normal University, Shanghai (2008) 20. Wang, Y., Dai, J.: Vocational College internship organization and management mode research. Wuxi Commerce Occupation Technical College Journal (12) (2009) 21. Liu, X.: To solve the problem of sound internship assessment mechanism. Higher Vocational Education Online (12) (2008)
Using PERT/CPM Technology for the Development of College Graduates Seeking Employment in Project Planning Xiaoqing Lu, Shuming Guan, Ruyu Tian, and Wenyi Zhang College of Science, Hebei United University, TangShan, China [email protected], [email protected], [email protected]
Abstract. Program evaluation research technology (PERT) and the critical path method (CPM) have become widely recognized as valuable tools for the planning and scheduling of large projects.These methods provide a strong theoretical basis for the managers in planning, arranging progress, dealing with the impact of uncertain factors and controlling cost. When it is difficult to accurately estimate the time of some activities, Three estimation methods of PERT can calculate the approximate probability of completing the project within the required time too. For using the PERT/CPM technology of Operational Research, This paper made the employment in project planning for the college graduates, help them to remove terrified mind and gain time and opportunity before getting a job. Keywords: PERT/CPM, project planning, double mark network diagram, probability.
3. What are the non-critical paths, which will not delay the whole project if they can not be completed on time? 4. What is the probability of completing the project before a specific date? 5. Whether we have sufficient resources to complete the project on time? 6. What is the best method to complete the project with minimum cost? You want to complete it within a relatively short time [3] [4]. There are several steps as follows need to be considered in making the project planning.
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The Establishment of Project Planning
In preparing the project planning, project leader is asked to decide what tasks to complete, clear each of the tasks to be completed prior to the event, and estimate that the time used to complete the task [1][10]. The following table, for example, lists all the key events that a graduate need to complete before the interview. Key events A. Complete the online registry and submit it to the job center. B. Pay attention to the trend of the Job Center and obtain the necessary information and the process of campus recruitment from it. C. Write the first resume. D. Find jobs outside the campus recruitment online E. Take part in the companies’ recruitment outside campus, take a knowledge of the companies’ culture and communicate with company representatives. F. Look over industry information from job center, take part in the employment testing, communicate with schoolmates and discuss every kinds of jobs. G. Participate in simulation interviews organized by the Job Centre and learn interview skills. H. Submit the first resume to the Job Center. I. Obtain the advice on modification by communicating with the resume experts. J. Modify the first resume. K. Participate in the campus recruitment, collect the introductions of companies, have conversations with companies representatives and submit resumes to them. L. Search for job information on campus and find the job you have the right qualification for it and interest in it. M. Determine the job you want to do. N. Obtain the interview opptunities of companies who participate in the campus recruitment and have an open kind of interview. O. Write cover letter to the companies who don’t attend the campus recruitment or they do but have close interviews. P. Submit the cover letter to the Job Center for inspection. Q. Modify the cover letter. R. Deliver a cover letter and resume to the recruitment department of companies who didn’t take part in the campus recruitment.
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S. Submit the cover letter and resume to the Job Center, for the companies who attended the campus recruitment but had close interviews. The immediate event of every event A. No. B. No. C. No. D. No. E. No. F. Complete online registration form and forward to the employment center. G. Complete online registration form and forward to the employment center. H. Complete online registration form and forwarded to the employment center. I. Submit the first resume to the employment center. J. Obtain the advice on modification of the first resume by communicating with the resume experts. Modify the first resume. K. See industry description, take employment testing, and communicate with schoolmates. L. Search employment information on internet and in table of campus recruitment, take part in campus recruitment. M. Decide oneself to be engaged in the job. N. Decide oneself to be engaged in the job. O. Take part in the companies recruitment. P. Write an application letter. Q. Submit the application letter to the employment center. R. Modify the application letter. S. Modify the application letter. Time used to complete the every event A. One day(including the time that the Job Centre deals with the registration forms.) B. Five days (Including the time that the Job Center checks resumes.) C. Seven days. D. Ten days. E. Twenty-five days. F. Seven days. G. Four days. H. Two days(Including the time that the Job Center check resumes.) I. One day. J. Four days. K. One day. L. Five days. M. Three days. N. Three days. O. Ten days. P. Four days(Including the time that the Job Center check covers letters) Q. Four days. R.Six days(Including the time of printing application materials) S. Two days(Including the time of printing application materials)
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Using PERT / CPM to Arrange Project Schedule
First, map out the double-arrow network diagram of key events of the project (Fig. 1). In the drawing of the network diagram, there are several things to note: (1) Total starts, total completion issues are unique (2) Requirement of numbering: the total matter as a start is No.1, the numbers aren’t repeated, and the total completion is related to END; (3) The progressive relations and following relations between works must be correctly said.
Fig. 1. The double-arrow network diagram of key events of the project
By Fig.1, the critical path of the project is: E →O→ P→Q→ R. Expected time required for completion of the project is: 25 +10 +4 +4 +6 = 49 days. Critical path is the longest path in all the paths of the network map, on that, any activities are the bottlenecks that will result in delays throughout the project duration if some activity is delayed.
4
The Improvement of the Modified Project Networks
If some key events missed when the project planning is drawing up, we must timely supply key events what missed in the networks and modify the critical path. For example, the student knows Job Fair on campus will hold after twenty-four days [4]. So we can add the key events missed in the project planning in the networks, Fig.2 is the modified networks. In the figure, we can discover the modified critical path [7] [11]: K′ → K → M →O → P →Q → R
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Estimate the complete time of the project is: 25+1+3+10+4+4+6=53 days.
Fig. 2. The modified networks
5
Disposal of the Probability Issue of Uncertain Activity Duration
In practice, if it is difficult to accurately estimate the time of some activities, we can use three estimation methods of PERT to calculate the approximate probability of completing the project within the required time. According to the calculation results, we can infer that whether the project can be completed successfully within the specified time or not[8][9]. The three time estimates of PERT are: the maximum possible estimate (m), optimistic estimate (o) and pessimistic estimate (p). μ =
o + 4m + p ,σ 6
2
p − o = 6
2
(1)
Formula (1) can be used to calculate the approximations of the mean and variance of the activity duration [5]. To simplify the solution process, we can obtain the mean and variance by Excel, in the E9, G9 cell, input functions "ROUND ((B9 +4 * C9 + D9) / 6,0)" and "ROUND (((D9- B9) / 6) * ((D9-B9) / 6), 2) ", we can obtain dates’ in E row and G row listed under the table.
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The calculation steps of probability that the graduate must complete all the key events with 60 days: (1) Identify the mean critical path in the network diagram (Figure 2):
K′→ K → M → O → P → Q → R (2) Calculate the mean and variance of probability distribution of the project duration (i.e., the mean or the sum of variances on the mean critical path) [2]:
(3) Calculate the probability that the project is completed within the specified time: Inputting function "NORMDIST (60, 53, SQRT (5.05), 3.11)" in Excel software, we can obtain the probability to complete the project within 60 days P (T ≤ d) = 0.99908.
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References 1. Hillier, F.S.: Data, Models and Decision-making. China Financial and Economic Publishing House (2006) 2. Hu, Y.-q.: Operational Research. Tsinghua University Press (2003) 3. Zhang, D.-l., Gao, O.-s.: Process Network and Its Critical Quality Chain Analysis Based on Quality Loss. Operations Research and Management Science 18(1), 151–155 (2009) 4. Li, J., Wang, R., Yang, Y.: A New CCPM Scheduling Algorithm Based on Resource Conflict Solution. Journal of Northwestern Polytechnical University 28(4), 547–552 (2010) 5. Yang, Y., Liu, L., Chen, L.: The Comparison of the Advantages and Disadvantages for Critical Chain and PERT/CPM. Value Engineering 12 (2008) 6. Wu, S.: The Application of Critical Path Method and Critical Chain Method in the Construction Management of Large-scale Engineering Project. Journal of Neijiang Normal University 23(10), 48–51 (2008) 7. Xie, Z., Mo, T., Tan, G.: Dynamic Job-shop Scheduling Algorithm of the Non-closejoining Operations. Chinese Journal of Mechanical Engineering 44(1), 155–160 (2008) 8. Ravi Shankar, N., Sireesha, V., Phani Bushan Rao, P.: An Analytical Method for Finding Critical Path in a Fuzzy Project Network. Int. J. Contemp. Math. Sciences 5(20), 953–962 (2010) 9. Ravi Shankar, N., Sireesha, V., Srinivasa Rao, K., Vani, N.: Fuzzy Critical Path Method Based on Metric Distance Ranking of Fuzzy Numbers. Int. Journal of Math. Analysis 4(20), 995–1006 (2010) 10. Ismail, A., Rashid, K.A., Hilo, W.J.: Literature Review in Resource-Constrain Critical Path Method Techniques. European Journal of Scientific Research 29(2), 222–236 (2009) 11. Xie, Z., Liu, S., Qiao, P.: Dynamic job-shop scheduling algorithm based on ACPM and BFSM. Journal of Computer Reseafch and Development 40(7), 977–983 (2003) 12. Christoph, S.T.: Job shop scheduling with altemative process plans. Int. J. Production Economics 74(1-3), 125–134 (2001)
The Research for Effecting to Basic Mathematic Based on PCA Junna Jiang, Linlin Liu, and Xinchun Wang College of Science, Hebei United University, Tangshan 063009, China [email protected]
Abstract. Here are many factors to effect to basic mathematics, for example the importance of mathematics, interest in mathematics, school emphasis, the work load of teachers. In this paper we use the way of principal component analysis (PCA) to analysis those affections, aim to get better teaching quality and make a contribution in math teaching fields. The result will help the teacher to choose better way to improve performance. Keywords: spss13.0 software, principal component analysis.
1
Introduction
The courses of basic math in University is considered dull, boring, and difficult to learn openly, how to improve the effect of teaching mathematics is a difficult problem that many universities face in teaching. In this paper we use principal component analysis method to analyze the effect of various factors on the impact of teaching, as for the factors diversity and complexity.
2
Principal Component Analysis (PCA)
2.1
The Definition of PCA
In practice, the study of multivariable problem is often encountered, but in most cases, between different variables have some correlation. Since many variables, plus variables have some correlation is bound to increase the complexity of the problem. Principal component analysis on principal component analysis is used to describe the composite indicator of the few links between many of the indicators, with less information on several indicators to reflect most of the information the original statistical analysis. For multi-variable data in the plane better integrated and streamlined to ensure that data is lost in principle at least, for high-dimensional variables reduce the dimensions of space, obviously, in a low dimensional space to explain the system, a high-dimensional systems than in space much easier.
The Research for Effecting to Basic Mathematic Based on PCA
n samples, each sample has p X 1、X 2、 .....、X P , and we get the original data matrix: There
are
x11 x 21 X = ... x n1
x12 x 22 ... xn 2
observed
301
variables:
... x1 p ... x 2 p = ( X 1 , X 2 ...., X n ) ... ... ... x np
p vectors X 1、X 2、 .....、X P of data matrix, that is F1 = a11 X 1 + a 21 X 2 + + a p1 X p F = a X + a X ++ a X 2 12 1 22 2 p2 p comprehensive index vector: , above F p = a1 p X 1 + a 2 p X 2 + + a pp X p 2 2 2 equations requested: a1i + a 2 i + ...... + a pi = 1 . In solving practical problems, generally not take p main component, but get previous k according to the size of the cumulative contribution rate.
Do linear combination with
λ1 / λi ，as p
Said that the contribution rate of the first principal component is
i =1
for
，
p
Var ( F1 ) = λ1 so λ1 / λi = i =1
Var ( F1 ) p
Var ( Fi )
.
i =1
Therefore, the contribution of the first principal component is the first component of the variance in the ratio of total variance. The more the value of it the more strong
.....、X P . ability to combine the information of X 1、X 2、 The first two principal components of the total contribution rate is defined as p
(λ1 + λ2 ) / λi i =1
is defined as
，The first k
k
p
i =1
i =1
λi / λi
principal components of the total contribution rate
. If the first
k principal components of the total
contribution rate gets 85%, it means the first k contains all the information measured, This not only reduces the number of variables but also to facilitate the analysis of practical problems and research.
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2.2
The Steps of PCA
(1) Standardization of data processing
Yij =
X ij − X j , where: i = 1 ,2 , ⋯, n is point of samples; j = 1 ,2 , ⋯, p is the Sj
amount of original sample.
X ij =
1 n 1 n , X S = ( X ij − X j ) . ij j n − 1 n i= i =1
After standardization, the mean and variance of each sample were 0, 1. (2) Calculated the correlation matrix of variables R Let the sample correlation matrix
rij =
R = ( rij ) = X , X
， Correlation coefficient
1 , and rij = r ji , rii = r jj = 1 . So R is symmetric matrix, the main n −1
diagonal elements are 1. (3) Calculated eigenvalue
λ1 ≥ λ2 ≥ ...λ p > 0
of the correlation matrix of
variables, and the Eigenvector corresponding
α 11 α 12 α 1 p α α α 21 22 2p α 1 = , α 2 = ,, α 1 = α p 2 α p1 α pp (4) Write the main component according to the cumulative contribution rate guidelines p
Calculate the contribution of each principal component
λ j / λi
, as the
i =1
cumulative contribution rate guidelines, that is as for Cumulative contribution rate k
p
i =1
i =1
λi / λi ≥ 85%
3
is standard, write the main component:
Fi = α 1i X 1 + α 2i X 2 + + α Pi X P , i = 1,2 p
Effectiveness of Mathematics Teaching Based on PCA
The effect of mathematics teaching we summarize that the following 12 factors:
X 1 = The importance of mathematics X 2 = Interest in mathematics X 3 = School emphasis X 4 = The work load of teachers
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303
X 5 = Teacher professional knowledge and practical rate of convergence X 6 = The enthusiasm of teachers X 7 = Textbook update rate X 8 = Attractiveness of the course X 9 = The importance of the course X 10 = Examination of the Difficult X 11 = Satisfaction of the teacher X 12 = Learning attitude By factors of nature, these 12 indicators can be divided into three categories:
X3 X8 X X 4 9 X1 G1 = , G2 = X 5 , G3 = X 10 X 2 X X 6 11 X 7 X 12 Do PCA for
G1 , the result in table 1,2. Table 1. EV, CR and CCR of
G1
Index
PCA 1
PCA 2
EV
4.3536
0.3431
CR %
92.1727
7.8130
CCR %
92.1727
100.000
Table 2. Eigen vector of
G1
Index
PCA 1
PCA 2
X1
0.4512
0.0210
X2
0.4803
0.6816
Because the contribution of the first principal component is as high as 92.1727%, so I can just take this one to replace the original principal component 2 indicators. The main components of the feature vector components are about 0.45, indicating that the original two indicators of the influence of the principal components are almost equal. The new comprehensive index is F1 = 0.4512 X 1 + 0.4803 X 2 . Similarly, we can do the principal component analysis for G 2 . Results are as follows table 3, 4:
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G2
Table 3. EV, CR and CCR of
Index
PCA 1
PCA 2
PCA 3
PCA 4
PCA 5
EV
3.160
1.544
0.303
0.215
0.114
CR %
91.356
7.0120
1.2524
0.4620
0.0455
CCR%
91.356
98.368
99.620
100.00
100.00
Table 4. Eigen vector of
G2
Index
PCA 1
PCA 2
PCA 3
PCA 4
PCA 5
X3
0.5210
0.0120
-0.2475
-0.3562
-0.0213
X4
0.1265
0.4140
0.3562
0.2561
-0.1351
X5
0.4231
0.3620
0.2456
-0.1289
-0.2356
X6
0.4002
0.7112
0.5647
0.4512
0.2451
X7
0.2615
0.0391
0.7450
0.3214
0.3041
Because the contribution of the first principal component is as high as 89.1368%, so I can just take this one to replace the original principal component indicators 5. The principal components from the weight of feature vectors of view show that the original five indicators of the influence of the principal components are different. The new comprehensive index can be expressed as:
F2 = 0.5210 X 3 + 0.1265 X 4 + 0.4231X 5 + 0.4002 X 6 + 0.2615 X 7 Similarly, we can do the principal component analysis for G3 . Results are as follows table 5, 6: Table 5. EV, CR and CCR of
G3
Index
PCA 1
PCA 2
PCA 3
PCA 4
PCA 5
EV
3.160
1.544
0.303
0.215
0.114
CR %
89.136
5.2180
3.0165
1.9440
0.5125
CCR %
89.136
94.354
97.371
99.415
100.00
The Research for Effecting to Basic Mathematic Based on PCA Table 6. Eigen vector of
305
G3
Index
PCA 1
PCA 2
PCA 3
PCA 4
PCA 5
X8
0.4561
0.1382
0.1025
-0.1230
-0.0210
X9
0.4325
0.0752
-0.0510
-0.1235
-0.2531
X 10
0.2652
0.5641
0.3245
0.1868
0.1256
X 11
0.4890
0.4210
0.3652
0.2014
0. 0124
X 12
0.4335
0.3000
0.3850
0.5810
0.4070
Because the contribution of the first principal component is as high as 91.3563%, so I can just take this one to replace the original principal component indicators 5. The new comprehensive index can be expressed as:
F3 = 0.4561X 8 + 0.4325 X 9 + 0.2652 X 10 + 0.4890 X 11 + 0.4335 X 12 4
The References Section
Three principal components shown above, basically reflects the original all the information, the first principal component and the importance of mathematics education, values are closely related, largely reflects the social aspects of this combination of factors. The second principal component with the school emphasis, teacher professional knowledge and practical integration rate, the enthusiasm of teachers related to teaching this largely reflects a combination of factors. The third principal component and the importance of curriculum, teacher satisfaction, attitude towards learning related to that of students generally reflect a combination of factors.
References 1. 2. 3. 4. 5.
6.
Sheng, Z., Xie, S., Pan, C., Zhang, D.: Probability and Mathematical Statistics. Higher Education Press, Beijing (2001) Shi, L., Cui, Y.: Educational theory: the principle of teaching, strategies and research. East China Normal University Press, Shanghai (1999) Petersen, I.R.: A stabilization algorithm for a class of uncertain linear systems. Systems and Control Letters 8, 351–357 (1997) Brenier, Y.: Convergence of the Vlasov—poisson system to the incompressible Euler equations. Comm. Partial Differential Equations 25, 737–754 (2000) Foster, I., Kesselman, C., Nick, J., Tuecke, S.: The Physiology of the Grid: an Open Grid Services Architecture for Distributed Systems Integration. Technical report, Global Grid Forum (2002) Puel, M.: Etudes variationnelles et asymptotiques des problemes de la mecanique des fluids et des plasmas, PhDthesis, Universite Paris (2000)
Research and Application of Five Rings Model in Mathematics Courses Reformation for Engineering Students in Independent College Nan Ji1, Qiuna Zhang2, and Weili Chen2 1
College of Science, Hebei United University, Tangshan, Hebei Province, China 2 College of Light Industry, Hebei United University, Hebei Province, China [email protected]
Abstract. In this paper, from the analysis of the independent college for the present situation of mathematics curriculum, the necessity of the reform of the course is analyzed. And then, from the aspects of the theory and practice, the whole optimization for higher mathematics teaching and curriculum system in independent colleges is expounded and analyzed. Then five rings model is applied to the reformation of the mathematics course. Keywords: five rings model, engineering students, independent college, mathematics courses.
1
Introduction
At present, according to the present situation of the independent college, the mathematical course teaching for most engineering students cannot implement the goal of training applied talent, and there is a certain distance with their level. [1,2,3,4] According to the specialty demand and the background of students, mathematics curriculum is divided into five rings. The main manifestation has the following six aspects:
2
Problem Analyses in Mathematics Course Teaching of General Independent Colleges
2.1
Independent Institute Student Mathematics Foundation Universal Somewhat Low, the Study Interest Is Not High
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2.2
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The Different Specialized Student Is Different to Mathematics Class Curriculum's Demand, but the Content Actually Same
The education aim of independent institute is training applied innovative talents, the significant difference with the teaching of the second batch of undergraduate students is the more emphasis on application, So each specialized to mathematics class taught by the scope and master the difficulty of different requirements, unified knife method of teaching content is very clearly not arrange for all professional requirements. 2.3
The Degree of the Teaching Way Close to the Independent Colleges Engineering Students' Professional Characteristics Is Not High
Because the teachers come from the parent substance colleges and universities generally, by the influence of two batch of undergraduate course teaching way, the independent institute is presented the initial period mathematics class curriculum the level which launches from the content on the level of the look, mostly continues to use the tradition “the concept -> theorem (conclusion) -> the sample question” the fixed pattern, the theory introduction lacks the actual background the upholstery. In the last few years, we are attempting increase the theory actual background and the application value, but had still not formed with the independent colleges and universities engineering course class student specialized characteristic drawing close to teaching way. 2.4
Lack of the Teaching Materials and the Teaching Outline Which Is More Close to the Professional Characters
Presently, mathematics teaching material which is suitable for the independent institute are not very few, but material of press close to the independent institute of professional teaching is still relatively poor, and not much choice. 2.5
Lack of Targeted Students' Experiment Link
Relative to the theoretical foundation of the independent college students generally very low, most of the present situation of the students' practical ability is strong, however, the current teaching of mathematics courses is mainly to teach, leaving the students hands-on opportunity to practice less, and therefore it is difficult to mobilize the active participation enthusiasm of student for learning. 2.6
The Age of Teaching Team Is Generally Shorter
Because the time of the independent institute establishment is quite short, the introduction of full-time teacher's age structure, educational structure, job structure, sex structure and the learning edge structure is difficult to achieve the desired
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requirements, mostly recruited two batch of undergraduate course universities teacher to teach, so the teaching content and methods are also not fully consistent with the status of student learning and professional requirements.
3
Reform Measures about Mathematics Course Teaching of Independent Colleges
To cultivate innovative talents "application" as the goal, to study mathematics curriculum of independent institute classification of the reform of teaching as a breakthrough, we will carry out in-depth mathematics teaching mode of research and practice for the independent institute of engineering students. Gradually to cultivate students have more skilled the basic computing ability, self-study ability, the comprehensive use of knowledge to the ability to analyze and solve problems. In the teaching implements “take the application as the goal, take sufficiently as the principle. We place the teaching focus on the ‘grasps the concept, simple the theory, strengthen the application, raise the skill’. [10] 3.1
Conformity Optimization Course Content
(A) The traditional mathematics including three courses: higher mathematics, linear algebra, probability and statistics to the whole mathematics curriculum of unity for engineering students' professional demand by semester into three stages; (B) Put the mathematical culture, intuitive mathematics and the content of the mathematical experiment in the teaching, through close together joint engineering students' professional background of mathematical culture background introduction, students' learning mathematics caused the passion. Through the math concepts direct of introduction, so that the boring and hard to understand math concepts and mathematical problems visualization, more benefit at the students understand the essence of mathematics; The introduction of the mathematical experiment content change student's study way, let the students' learning from passive to active participation, accept to strengthen students learn, with good mathematics selfconfidence, to cultivate students innovative design ability; the active At the same time, course design to join, so that the students can better combined with the practical application of mathematics specialty. 3.2
Consummation and Improvement Teaching Method
(A) The traditional teaching method of the essential form: (pure theory explains, the entire journey is completed by teacher) (see figure 1).
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Fig. 1.
(B) After the improvement overall subject teaching method's fundamental mode (student participates in teaching process, increasing the practice link) (see figure 2)
Fig. 2.
3.3
Reform of Examinations
Take the following test method of combining three models: (A) Basic knowledge test (closed book), examining the basic principles, mastery of basic skills;
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(B) Mathematics experiment test (opens a book to submit report), examines the degree of knowledge to the student grasping, and the ability of using the software to solute actual problem; (C) Usual performance (normal operation results of students score + competition results + attendance credits). Total score of the final semester of the students is as the following figure3:
Fig. 3.
3.4
Development Construction Curriculum Website
To establish the curriculum website, we can use the network issue curriculum information and the teaching resources, lets the student participate in the curriculum the construction, stimulating student’s studies enthusiasm, enhancing the study effect, promoting the curriculum to construct effectively. The concrete content includes the following aspects: [11] (A) Release of the teaching resources and information (B) On-line question-answering, the teachers and students interact. (C) Homework review on-line (D) Examination on-line
4
Conclusion
Through reform, to achieve the following objectives: integration and optimization of the content of mathematics curriculum of an independent college of engineering
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universities, making mathematics courses closer to the professional knowledge the students have learned. Pay attention to curricular and extra-curricular classes associated, focusing on class and strengthen practical aspects of mathematics and mathematical experiments. At the time of imparting knowledge, we develop the student’s ability of the sense of self-learning and innovation capacity, enhancing student interest in learning.
References 1. Ji, M.x.: On Talents Training Goal Positioning and New Approach to “Practical” Talents Training in Independent College. J.Shanxi Agric. Univ( Social Science Edition) 6(3), 321– 324 (2007) 2. Xiong, H.: Reflection on the Teaching Reform of Higher Mathematics in the Independent Colleges. Journal of Hang Zhou Dianzi University (Social Sciences), 71–74 (2008) 3. Xiong, D.: On reform of advanced mathematics teaching in independent college. Journal of Wuhan Institute Technology, 81–83 (2009) 4. Anna, S.: On Reform Movement and the Limits of Mathematical Discourse. Mathmatical Thinking and Learning, 157–189 (2000) 5. Ge, J.: Research and Practice on Overall Optimization of Higher Mathematics Course Content and Curriculum System in Independent Colleges. J. Northeast Agric. Univ (Social Science Edition) 7(1), 57–59 (2010) 6. Tian, B.: Exploring on the Strategy of the Higher Mathematics Teaching Replied on the Elementary Education Reform. Journal of Chongqing University of Arts and Sciences (Natural Science Edition), 106–108 (2008) 7. Li, L.-f.: Practice and Research of the Instructional Reform of Advanced Mathematics Curriculum. Journal of Educational Institute of JiLin Province, 102–103 (2010) 8. Zou, Y., Guo, S.: Advanced Mathematics Quality Evaluation Based on Grey Correlation Analysis. Journal of Hefei Teachers College, 16–20 (2009) 9. Ji, N., Lei, Y.: An Application of Software R in Computation of Parametric Estimation. In: ICEMSE 2010, pp. 767–770 (2010) 10. Information on, http://www.ceat.edu.cn 11. Information on, http://www.docin.com/p-88235781.html
Practices and the Reflections on the Bilingual Education Hai-chao Luo, Kai Zhou, Teng Chen, and Wei Cao Henan Institute of Science and Technology, Xinxiang, Henan, China [email protected]
Abstract. Bilingual teaching is the inevitable trend of the development of China's higher education reform and with international standards.The goal of bilingual education is to enable students to master the professional knowledge, ability to simultaneously use both Chinese and English languages professional learning and thinking. Bilingual teaching in Chinese universities is still in the process of exploration. In order to adapt to this mode of teaching, to achieve the desired effect of teaching, bilingual education must be practical and theoretical summary to find suitable ways of the construction of various types of courses. In this paper, to the construction of urban economics of bilingual education as an example, describes the construction of the practice of bilingual teaching, and think about the construction of bilingual education in China. Keywords: bilingual teaching, Urban Economics, Practice.
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undergraduates, the difficulties are relatively large for urban planning undergraduate students who had never learn about the “Socialist political economy” and "Western Economics". The Chinese teaching materials’ interpretation of the basic theory of urban economics is not enough detailed and vivid, English teaching materials have advantages in this area. In order to obtain the latest research focus, the academic theories as well as the latest reference materials in this field, it should study some of the original monographs, textbooks, journals and magazines. In accordance with these reasons, it has a strong feasibility to promote the implementation of the bilingual education. The author has taught the urban economics subject in the urban planning department for six years, and has applied for the bilingual education of this course in the recently two years. In the following, the author will introduce the practice and reflections on the bilingual education of the "urban economics".
2
Bilingual Curriculum Construction of the "Urban Economics"
2.1
The Selection of the Bilingual Teaching Model
The bilingual teaching model used contemporarily is basically belonging to the "transitional mode". The so-called transitional mode means to adopt original foreign language teaching materials and English blackboard-writings in the class, the teacher teaches the class alternately in English and Chinese, and students’ homework and the examination are assigned in English, some of which can be answered in Chinese. This model can let students acquire more professional knowledge and have lower requirements to the teachers, and have proved as the effective method that particularly suitable for the initial exploration phase of bilingual education. The teaching effect of the matter-of-fact bilingual teaching model is comprehensively preferable. 2.2
The Selected Teaching Material and the Proportions of Teaching in English and Chinese
The chairman of China Society of Urban Economy Curriculum Construction Professional Committee Guo Hongmao believes that: “the general research of urban economics theory and should be different from the compile of teaching materials. The former focused on the task of theoretical innovation while the latter emphasis more on the introduction of the research achievements and the research methods. Therefore, it should select the research achievements in the teaching materials especially in theoretical models, select the research model recognized effective and that suitable for China's actual conditions so as to facilitate students, especially undergraduates’ master of the basic theories and methods.” According to Guo Hongmao’s compiling requirements of the teaching materials as well as the consideration of Chinese students’ professionals and English learning conditions, we selected the English
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version 4 of the “urban Economics" compiled by American scholar Arthur O'Sullivan as the main reference material, in which the author interpreted his unique economic interpretations with simple, vivid and easy to understand language and accompanied a large number of urban realities. The analysis point of view of this teaching material was of novelty, and explained the profound things in a simple way; the language was standard and the structure was tautness; the difficulty of English as well as the professional knowledge was suitable for teaching objects at the same time, which not only has the availability but also can properly implement the research-based teaching ideas. In line with the abovementioned reasons, we selected this book as the main reference material. From the perspective of the teaching content, the part 1, 2 and 5 will be the focused teaching content according to the characteristics of urban planning, strive to let students master these three parts. Other contents can be done a brief introduction based on the class hours. Adjust the proportions of teaching in English and Chinese according to students’ degree of English learning. The “Urban Economics" course is opened in the sixth semester, students by then have studied the college English for two years, most students have passed CET 4, some of them have passed the CET 6, and have initially possessed with the conditions of bilingual education, therefore, the ratio I taught English in my class is about 50%. In order to improve the teaching effectiveness, I conducted the teaching in small classes. 2.3
The Application of the Teaching Methods and Media
Previously, students have studied the college English but never accepted the bilingual programs, this is the first time that students receiving the bilingual education. However, they are still used to the English - Chinese - English psychological translation process; moreover, students can hardly thinking about the abstract principles in English especially for the basic course of the Urban Economics with strong abstract thinking. Therefore we adopt the method that mainly teaching in English with an addition of Chinese, English courseware, English reading and English answering. The teaching method employs the PowerPoint software multimedia courseware, in which there uses many pictures and video materials, and important concepts in urban economics like economies of scale, agglomeration economies, etc are focused marked and highlighted so as to reduce students’ learning difficulty. In the meanwhile, avoid using valuable class time to complete the complex spelling as well as the interpretation of the meaning of the word so that the quality of teaching will not be affected. What I consider more in my prepare of lessons is how to enable students to research and identify problems, try to stimulate their interests, guide their thinking and foster their ability, rather than considering how to say a term in English, whether the syntax is wrong or not, whether the word is new or not to the students and so on. Try hard to refer to a large number of relevant teaching materials in both English
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and Chinese; write teaching plans in English and cross reference of both English and Chinese technical terms. Mark out the board writing outline, keywords in class and the technical terms in the lesson plans. Try not to make bilingual education as the secondary class of foreign language teaching. 2.4
Assignment and the Evaluation System
The assignments that guide students to learn include: 1. assignments can be found the answer directly in the teaching material, which try to help students to master the basic concepts; 2. Assignments can be acquired the answer on the basis of the understanding of teaching materials with proper adjustment; 3. Assignments need to use the acquired knowledge to interpret and analysis some phenomena and problems exist in our country. All assignments are required to be answered in English, through which English can be audaciously used just as a communication tool. The evaluation of students’ performance is of flexibility; it combines the written examination and the oral test together, and adds the ratio of the oral test. The written examination resorts to the forms like closed book, open-book and semi-open-book, etc and all papers are assigned in English. The oral test combines the subjective and objective questions together and increased the subjective comments. Final exam accounts for 70% of student performance assessments. Other methods for the evaluation: attendance; class presentation that includes the initiative, the use of foreign language, clarity of thinking, etc; assessments; course work; etc. 2.5
Network Share of the Curriculum Resources
It should sufficiently adopt the network resources to the teaching of the "Urban Economics" and make the network as shared resources for both the students and the teachers. With the utilization of the teaching network platform, the students can freely enjoy the recourses like English syllabus, course agenda, the main teaching content of the discipline, focal points of each chapter, Introduction of domestic and foreign celebrities, the latest research advances, reference materials both un Chinese and foreign languages, relevant domestic and foreign professional site link, online teaching guidance and discussion areas, etc, fully mobilize the students’ enthusiasm and initiative.
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Reflections from the Bilingual Curriculum "Urban Economics"
In recent years, bilingual education attaches more and more importance in the colleges and universities’ teaching process, bilingual teaching of specialized courses has became a university initiated new teaching model. However, there are also exist many problems in the bilingual education, since the trail bilingual education of "Urban Economics", the author has a more in-depth experience for some of the issues and reflects some thoughts below. As shown in Figure.1
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Fig. 1. Analysis of factors affecting bilingual education
3.1
It must be Ensure the Effectiveness of Teaching as the Main Purpose of Bilingual Education
The most important aim of teaching is to impart knowledge, and allow students to master the necessary professional content in the limited hours. The bilingual education should not overemphasize too much on English but should take full consideration of teacher’s teaching ability and students’ reception, appropriately use English in the class under the premise of the warranty of the information content and the teaching effectiveness. Blindly pursuit of bilingual teaching and neglect the teaching effectiveness is shifting the burden and worthless. 3.2
The Bilingual Education should Penetrate throughout the Educational Process, and Closely Integrate the Curricular and Extracurricular Contents
English is the international language, some of the latest scientific and technological information are generally wrote in English, therefore, the personnel training of colleges and universities must pay attention to the professional English education. However, the English education should not just limit to the class after all that English is not our mother tongue. The effect of teaching in English is lower than that of in Chinese; the irregularity of students’ English levels can hardly ensure the overall teaching effectiveness. For these reasons, we should position the bilingual education at the school level and penetrate throughout the educational process; in addition to curricular teaching, it should also focus on the professional English education from perspectives of the extra-curricular activities, discussion, material reading, monographic study, experiment, exercitation and so on, try to build good educational environment and enable students to improve unconsciously. 3.3
The English Proportion of Bilingual Education should Be Practical and Realistic as Well as People Oriented
Under the premise of the warranty of teaching effectiveness, it should appropriately use English in the teaching so as to increase the student's professional English
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training; however, it should be practical and realistic as well as people oriented on the English proportion of bilingual education to avoid the “sweeping approach”. It should be handled flexibly in accordance with the nature of the curriculum, the professional needs, and teachers teaching ability and students’ reception so as to achieve the winwin objective of the enhancement of teaching effectiveness and the English capacity. 3.4
The Enhancement of Students’ Basic English Education and Teachers’ English Problem-Solving Ability Is the Basic of the Bilingual Education
The essence of the bilingual education is teacher’s teaching ability in English and students’ receptive capacity of English; therefore, institution of higher learning must view the enhancement of students' Basic English education and teachers’ English problem-solving ability as a regular and important task. On one hand, it should continue to deepen the reform of college English teaching, take effective measures to effectively improve the students’ overall English ability represented by the reading, listening and speaking; on the other hand, it should increase the intensity of the training for first-line teachers, try to send outstanding teachers to foreign universities for their further studies in addition to the school training so as to improve teachers’ English capacities.
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Conclusion
Bilingual education is the inexorable trend of Chinese higher education’s acting on international convention as well as the development of the educational reform, and is also the hot spot and focus of the current higher education reform. To meet the requirements of the Ministry of Education, colleges and universities have set up bilingual classes successively; however, from the overall point of view, "Bilingual education" in China is still in the initial pilot phase, and has a long distance with the objective of “enable students to think in English and freely switch with the mother tongue”, much still remains to be done. Teachers should decide what kind of teaching mode to use according to their actual situations, give full consideration to all factors so as to really achieve the purpose of bilingual education.
References 1. Guo, H.: The research about Urban Economics as a branch of Spatial Economics——three decades combing and thinking about China’s urban economics. J. The Comparison Economic and Social Systems 7, 5–14 (2010) 2. Wang, H., Wang, Z., Fang, J., Li, C.: The understanding and recommendations of bilingual teaching in colleges and universities. J. Peking University (Humanities and Social Sciences) 7, 293–294 (2007) 3. You, T.: A reseach about of problems and countermeasures of bilingual teaching in colleges and universities. J. China Adult Education 9, 141–143 (2009)
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4. Xiang, Z., Zhou, C.: The practice and thinking of methods and means of bilingual teaching in colleges and universities. J. Peking University (Humanities and Social Sciences) 6, 252–253 (2007) 5. Su, W.: Thinking and discussion of bilingual teaching of professional courses in colleges and universities. J. Educational Theory and Practice 8, 26–28 (2007) 6. Hu, M., Yang, Z.: The present situation and Countermeasure of bilingual teaching in colleges and universities. J. JAC Forum 9, 117–121 (2007) 7. Zheng, D.-h.: On the Construction of the Model of Needs Analysis in Bilingual Instruction. J. Foreign Language and Literature 1, 128–131 (2011) 8. Han, X.-y.: Application of Bilingual Teaching to Experiment of Cell Biology. J. Research and Exploration in Laboratory 7, 230–232 (2010) 9. Kan, J.-s.: Exploration and Practice of the Bilingual Teaching in Genetic Engineering. Journal of Anhui Agricultural Sciences 30, 17331–17333 (2010) 10. Shi, W.-s.: Discussion on Improving Bi-lingual Teaching in Application-oriented Institutes. Journal of Anhui Agricultural Sciences 26, 14804–14805 (2010)
Research on Problems and Countermeasures of China’s Urban Planning Education Hai-chao Luo, Li-fang Qiao, Zhi-hong Liu, and Xing-zhi Peng Henan Institute of Science and Technology, Xinxiang, Henan, China [email protected]
Abstract. Urban planning education in China is typically characterized by a vague orientation, redundant coursework, and repetitive models. Urban planning education reform should focus on social needs and human resources. Future goals, core courses, and different levels should be integrated into the system. Keywords: Urban planning, Education, Reform.
1
Introduction
We have witnessed a lot of hardships in the cause of China’s urban planning construction from not executing planning for 3 years, cancellation or merge of planning major to the rumor that “planning is the lie” and urban is the dissatisfaction with the countryside, even till the issuance and execution of Law of the People’s Republic of China on Urban and Rural Planning (abbreviated as Urban and Rural Planning Law), expanding city to the countryside in the planning field, confirmation of planning “leading” role, Beijing Olympic Games planning as well as the achievements made in planning for Shanghai Expo. In a word, this road is full of ups and downs. Currently, the scale of professional talent cultivation for China’s urban planning has been gradually expanded and the fields that the urban and rural planning involves have been extended gradually. Just as Lewis Mumford says: “It’s the profound social and economic reform that really changes urban planning” and all these deeds such as: establishment of China’s two-oriented society (energy saving and environmental-friendly societies), implementation of scientific outlook on development, rapid growth of rural economy, construction of metropolitan circle as well as the flourishing development of new rural construction will bring about opportunities for development and strategic selection to the urban planning major.
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Problems Existing Currently in Professional Education of China’s Urban Planning
orientation, to which the research on curriculum system corresponds and constitutes different subject characteristic; 2. research on optimized teaching of single curriculum or curriculum group; 3. research on planning theory and practice; 4. research on planning management and implementation. It could be said that these four categories of researches are closely and mutually related to each other, As shown in Figure 1. Under the circumstance of flourishing construction practice, the development of China’s urban planning major faces fabulous situation. However, there are also some realistic problems, which are mainly manifested in the following three aspects.
Fig. 1. Relationship of influence each other of four the study
2.1
The Loss of Identity during Learning
Urban planning is the “flagship” of the urban construction, which is beyond all doubt. However, there are a lot of embarrassments in practical urban planning. For instance, whether the urban planning major recruits liberal arts students or science students? The cultivated students shall be technical experts or generalists? The education time for the urban planning major shall be 5 years or 4 years? A series of uncertainties confronted by the teachers and students engaged in urban planning major education bring about the confusion of identity of urban planning major. The unclear major orientation brings about the loss of identity to the development of urban planning major. People have always been unable to decide whether the urban planning dependents on architecture or shall be unique in its own style. From the date of emergence, modern urban planning regulates the development of “urban region” by dint of legal guarantee based on the recognition of the public value. City is not only the aggregation of architectures, which is actually manifested by the multi-subject platform of China’s urban planning major education. 2.2
The Bleak Prospect When Graduation
Currently, the mainstream five-year professional education is similar to an aristocratic education. The cost of daily learning is very high. More, the students are required to
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have a stronger sense of social responsibility, thus the students have higher expected values upon graduation. Once the students encounter into the austere social employment reality, a kind of abnormal employment crisis will be caused easily, thus many students engaged in urban planning major feel their future is bleak. However, the expanded enrollment of the unrestrained major aggravates this contradiction. It could be said that this employment crisis is a relative surplus crisis substantially. On one hand, a part of students their careers or work in some small private design companies in the developed regions. Consequently, the talent aggregation density is very high and the competition is drastic in the developed regions and big cities. On the other hand, the talents are severely deficient in the underdeveloped areas, middle and small cities as well as the town areas, thus it advances difficultly due to the lack of professional talents of urban planning in the rapid urbanization process. 2.3
The Continuous Loss Upon Employment
Though the registered planner system has been promoted for many years in China, a lot of urban planning practitioners still feel confused during the work. It’s mainly for the following reasons: on one hand, the necessary association between the registered planner examination and school education is void; on the other hand, the space for the registered planner play the role is quite large if compared to the other similar registered planners in social practice. The macro guiding function of helping the urban planning practitioners establish the professional sense of urban planning is still developed.
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Thought of Reform in the Professional Education of China’s Urban Planning
With focus on the problems in professional education and social practice, it is imperative to implement reform in the professional education of China’s urban planning. In reform, it is necessary to tightly focus the three characteristics during the professional education of urban planning. 3.1
Forwardness of Goal
Education is the cultivation of a kind of quality and also the establishment of an ideal. Currently, the professional education of China’s urban planning lags behind the practice. Therefore, there is no way to have immediate and correct judgment and positive reactions over the changes in social situation, thus it is no easy to satisfy the social demands. It is necessary to change the too pragmatic education mode of the professional education of the urban planning so as to avoid the dilemma of seeing the doctor if the head aches and seeing the doctor if the foot pains. It is called that “it takes tens years to grow trees, but a hundred to rear people.” As the orientation of a major, its development goal should be not only accurate but also have appropriate forwardness of goal. The talent cultivated in such way has relatively longer
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adaptation. There is a saying that goes “30% planning and 70% management”. It will be “30% technology and 70% ideal if applied into the professional education of urban planning.” However, there is gap between the ideal and reality existing in the professional education of urban planning. For establishing ideal development model and direction for the urban planning, it is necessary to make planning schemes for different regions based on the realistic game playing. 3.2
Core of Cultivation
The enlightenments given by the development and reform of foreign urban planning could be generalized that each development and reform of urban planning and professional education of urban planning has its profound political and economic background. Although the development trend of foreign planning talent cultivation have been gradually transformed into the training development with focus on social science from the training with particular stress laid on aesthetics and engineering design, although the contradictions confronted by the cities currently become more and more complicated and these contradictions are all reflected into the urban material space, it doesn’t mean that as for the urban planning subject, it is necessary to study all social and economic relations and solve all social and economic problems. As for urban planning, a subject and industry, it is impossible and unnecessary to all the problems in urban construction and even in future urban development. “Provided that planning is anything, maybe, it is nothing at all”. In professional education, it is necessary to be clear about key problems in urban planning, like “who-oriented, who gives priority on people and whom people give priority on”, [3] etc. upon review and orientation of the core and essence of the subject, it is necessary to firmly set up the viewpoint that “the expansion of urban planning subject shall be established in the footstone that consolidates the space problem”. Therefore, the goal of the professional talent cultivation of urban planning shall be forward but its core should not be changed. 3.3
Level in School Running
Education is the education of the society while the talents are the talents of the society. The demand for talents is the reflection of the social demand. Education is the reaction satisfying the social demand. From the perspective of this point, school is the supplier while the society is the demand side. The products cultivated by the supplier in different regions and under different resource conditions are not only universal but have certain difference. However, each demand side has different requirements for products. Based on this difference, different school should have its own characteristics if setting up the urban planning major in order to survive by dint of characteristics to confirm the setting and development of the major according to the social demands and center on advantageous resource to run school innovatively. In the meantime, the philosophy of overall urban and rural planning and demand for focusing on livelihood put forward by Urban and Rural Planning Law greatly expands
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and extends the objects and range of urban planning work, and also puts forward new requirements for hierarchy of planning education.
4
Relevant Measures for Reform in Professional Education of China’s Urban Planning
Based on recognizing the three characteristics of professional school running, the reform in professional education of China’s urban planning could be started from the following three aspects. 4.1
Focus on Target Orientation and Hierarchical Labor Division in Talent Cultivation in Terms of Talent Provision
China has vast region. Different climates, folkways, social and economic backgrounds as well as the terrains create conditions for the development of urban planning cause and put forward requirements for multi-level school running. As for schools in different regions, their professional school running history and relied platforms are not the same. Certain school running mode and professional characteristic could be formed through definite professional orientations including: category orientation, cultivation standard orientation and service orientation. 4.2
Strengthening Professional Evaluation and Professional Continuing Education, and Set Up the Bridge between Communication Demand Side and Supplier
Though the current school’s professional evaluation defines the core curriculums and satisfies the basic requirements of the urban planning major for school running, the coverage of the evaluation still small. The due function hasn’t been still developed fully. If a rule is used to weight up the professional education of the urban planning across the country, then the bias will be generated and it is not advantageous to run school with their own characteristics. Therefore, it is appropriate to strengthen the professional guiding committee’s guiding role in each school’s major based on defining the core curriculums to expand the influences of the professional guiding committee on each school to run school with urban planning major. At the same time, as for the schools have passed through professional evaluation, the professional talents cultivated by them are given proper preferential policy in admission of registered planner and in relevant aspects. Finally, certain guidancequality is formed. Through the professional education of the registered planner is in progress, the effect is not remarkable with lack of in-depth research on planning compilation and management in different regions and under different conditions of economic backgrounds while the most just focus on the form. It is necessary to strengthen guiding the professional continuing education of urban planning; meanwhile, urban planning education shall be evolved into a quality education as soon as possibly. Only the improvement of overall qualities could ensure the formation of human settlement
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environment, give full play to the due functions of urban planning. Then the planning education popularizing whole people is useful to promoting the development of planning. 4.3
In Terms of Demand, the Sound Industrial Management Mechanism Provides the Platform for the Professional Talents to Give Full Play to Their Talents
In future, people’s participation in urban and rural construction and complaints over benefits will be increased in large quantity and the criticisms over the construction waste will be more and more. Thus, improving the comprehensive quality of the urban planners is a social recognition. Currently, a lot of urban planning graudates can not enter into the posts most appropriate for me to give play to functions due to various reasons in terms of the system. Therefore, it is necessary to perfect industrial management mechanism and define the system for the professional talents of urban planning to enter into the urban management departments so as to expand employment channels for the urban planning majors and provide platform for professional talents to give play to their talents.
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Conclusion
China’s higher education has stepped into the key period of popular education phase. The number of universities and colleges setting the undergraduate program of urban planning is increased sharply. To make the cultivated urban planning majors become competent in the drastic competition, it is an imperative to rely on and serve the local economic and regional economy for cultivation of professional talents of urban planning with stress laid on forwardness of goal, core of cultivation and level in school running to perfect the professional education of urban planning.
References 1. Zuo, J.: Should Urban Planning Education be More Professionalized? The Controversy in France and What We Can Learn from It. J. Urban Planning International 6, 87–91 (2010) 2. Chen, L.: Problems and reform Thought of Urban Planning Education in China. J. Planners 12, 102–104 (2010) 3. Ren, S.: Undergraduate Education of Urban Planning Based on the Demands of Employment Market: a Case Study of Huazhong University of Science and Technology. J. City Planning Review 9, 78–81 (2009) 4. Wang, X.: Learn from the West and Examine the Future of China Urban Planning Education. J. Urban Planning International S1, 136–140 (2009) 5. Huang, Y.: Development and Renovation of Urban Planning Education. J. City Planning Review 9, 70–87 (2009) 6. Liu, B.: From Knowledge to Capacity-Educational Reform on Urban Planning. J. Planner 10, 16–18 (1999)
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7. Zhao, M., Zhong, S.: Study on Urban Planning Education in China. J. Urban Planning Forum 8, 1–8 (1995) 8. Zhao, M., Lin, H.: The Deference of Urban Planning Education and its Institutional Context in China. J. Urban Planning Forum 11, 48–50 (2001) 9. Huang, T.: Some Suggestions on the Establishment of City planning Education System. J. Planner 9, 60–62 (2005) 10. Wang, J.: Strategic Consideration of Urban Planning Towards 21st Century. J. Urban Planning Review 9, 21–23 (1997) 11. Wu, Z.-q., Yu, H.: Development Direction of Urban Planning Discipline. J. Urban Planning Forum 6, 2–10 (2005)
The Research on Modern Information Technology in College Music Teaching Application Qiu Yan Fu Music department, Xinmin Normal College, Shenyang University, China [email protected]
Abstract. Along with the development of the education information, multimedia has been integrated into the music teaching. This paper carried on analysis and researches on the necessity and the importance of the multimedia technology in the universities’ music teaching. At the same time, current college music teaching use multimedia some drawbacks have been found. Integration of information technology and modern music courses is reasonable. This paper is based on some researches on how to improve the teaching quality and teaching effect using combination of music software and traditional media by combining music software and traditional media in practical works. Keywords: Multimedia, Music education, Computer application technology.
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Introduction
With the deepening of the educational modernization, multimedia has shown its unique charm in music teaching. It expanded the capacity of the music class teaching greatly, enriched the ways and resources of teaching and provided a vibrant music world for the teachers and students [1-2]. In music teaching, multimedia shows its effectively advantages, it can greatly stimulate the students' study interest in music, enrich the students' imagination, creativity, expression, and deepen our understanding of the music [3-4]. Therefore, multimedia computer has been widely used in music teaching. Along with the rapid development of computer technology, it makes the computer application field more widely. Computer application affects various aspects of the society, we can find it also play an important role in music teaching in universities. Computer multi-media technology is applied in the music teaching, it does not only solve the problem which is already existed in traditional teaching a long time, but also can receive better teaching effect and have very important practical significance.
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Necessity of Applying Computer Technology into Music Teaching
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teaching gradually [5-12]. But in the universities of China, the blackboard and piano is still the main teaching tool in music course, the teaching way influences the development of teaching further. Taking the process of harmonic teaching as an example .When the teachers write the music score on the blackboard, it is difficult to form the music in heart of the student, and the music comes from the piano disappears in a moment. Because of the students can't see the forming of the music, it often appears “seeing no, hearing no” psychological confusion. Although the teacher explains very seriously and the students studies very hard, students often gets just some abstract and complex rules. At last, most of the students lose their interest in studying harmonic. For this reason, we consider to establish good tone quality and stereo effect in the teaching process, and to make the students sense rich expressional force of the harmonic language, improve the students' enthusiasm in studying course, then grasp the general rule of harmonic further. It broadens the range and vision of teaching, improves the efficiency of studying. Computer music technology is the most effective means to carry out this teaching thought. Using it could form the visual, auditory integration, and this way of teaching will receive a better effect. It is obvious that introducing computer music technology into our music course of universities in our country is around the corner. It is helpful for improving the students' interest in studying, and it is also essential teaching tool to improve the teaching quality.
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Importance of Multimedia Technology in Music Teaching
3.1
Stimulating the Students' Interest in Studying
The multimedia technology could provide all kinds of vivid scene, and it designs different situation accord to the words, graphic and music. This kind of technology makes the student to obtain training about the ability of using music actually, and it is good for arousing students' interest in studying. In the process of teaching, the teacher designs and organizes the teaching according to the teaching contents, makes full use of multimedia combination to create the scene that attract students to participate actively. In the inspiration and guidance of teacher, the students are able to explore independently and participate in teaching activities energetically, creating a dynamic atmosphere that we can sing and communicate with each other. The appropriate encourage and consciously train of the teacher will improve the ability of expression and quick thinking of the students, so that the students feel the fun of study music. At the same time, it stimulates students' interest in studying, so as to achieve the once more teaching result than before. 3.2
Change the Traditional Methods of Teaching and Increase the Capacity of Class
Music for inspiration, inspire man wisdom has a promoting function, but the students often feel indifference about it. The main reason is that traditional teaching method is
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rather drab, and it is hard to arouse the enthusiasm of the students, the study content is a single. Make use of the multimedia teaching means, the teacher made courseware carefully before the beginning of the class. The teacher teaches with the fascinating courseware, which saves time, focus on the students' attention and improve the students' interest in the teaching class. The teaching method arouses the enthusiasm of the student and makes them receive more knowledge in the provision of time. 3.3
Make Using of Multimedia Teaching to Improve Students' Aesthetic Ability
The famous musician Liszt said that music could be called the universal language, human feelings could talk to any minds and be all understand in the language. When the music provides man with a kind of hearing beautiful image, the appreciators’ feeling of complex life, understanding of life phenomenon, and the ideal of aesthetic life, which condensed the certain feeling, and it expresses through the rhythm, tune, tone and the structure of music. After hearing the particularity of art aesthetic, it is decided by the aesthetic ability training. In aspect of the music, it can change abstract theory in materialization, thereby we could get good teaching effect. Music education can cultivate music cultural quality and aesthetic ability of the student, make he or she become a human with the perfect personality. The essence of music education is aesthetic education, and it is also the important content of carrying out the quality education in current. Make use of multimedia teaching, it is easy to let the students build up the image of the aesthetic in the heart and produce the cheerful emotion. With the flow of music, a series of vivid pictures appearing in front of your eyes. For example, “The Yellow River chorus” is a very famous work of Xian Xinghai. The eighth movement “Defend Yellow River” and the ninth movement “Roar! Yellow River” in “The Yellow River” are both very wonderful. In the background of the Yellow River, the music eulogizes the enthusiasm of the Chinese nation and the spirit of struggle from beginning to end. It is reflects the people's patriotic upsurge and the faith of victory successfully. In the process of showing the video, the background of the Yellow River, the band's music, chorus is powerful. It makes the students to feel the majestic momentum and spirit of struggle of people strongly. The students accept the education and influence of beauty in the deep heart, thus it has improved the aesthetic quality of the students.
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Integration Multimedia Technology and Music Class
Proper selection of the computer music teaching software is the core of integration of Information technology and music course teaching. Music teaching and computer music software combines method is shown in Table 1.
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Table 1. Music teaching and computer music software combines method
Project Music editor Music making Recording
Computer music software Syntrax, ElectrumDrumMIDI GenieSoftOverture, Sibelius CoolEdit, Adobe Audition
Teachingcontent Music appreciation Music theory teaching Learning evaluation
Music teaching and the combination of computer music software should also pay attention to the following questions: The integration is not only the sum in the simple sense, but a comprehensive penetration. The whole function of it should be more than the total function of the sum of the parts after the integration. Integrated system should have multiplicity, vitality of the studying process and the characteristic of multiple perspectives, multilevel and so on in gaining the knowledge. The using of multimedia technology should still reflect the purpose of the music teaching. Make use of multimedia technology to put the students into an appropriate situation to make them to feel the music, it provides the favorable conditions of music aesthetic and emotional experience. The teacher shows outstanding works about different nations in different periods through the audio-visual techniques of multimedia technology, so that the students can feel the charm of the music world. Integrated system should have strong expressive force, colorful show forms, abundant teaching content and so on. The man machine interactive function of the multimedia technology should be committed to change the traditional mode that the teacher as the center of the teaching and arouse the subjective initiative of students. At the same time, we should increase the interactive in courseware and improve the ability of teachers to control the modern information technology.
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The Role of Teacher in Multimedia Assistant Music Teaching
The multimedia teaching is just an assistant approach, its core is to make use of multimedia forms and contents. The teacher is still in dominant position in the process of teaching. If the role of teachers is just as the simple operator of the machine that no longer has communication with students, then significance of teaching is not exist. In the process of multimedia assistant music teaching, the teachers should become the organizer and guider and play the leading role fully. The teachers must continue to absorb new knowledge, update the structure of their knowledge, improve their comprehensive quality and establish a new relationship with students. The teachers' ability of studying and the level of modern educational technology are the important factors, which decide the result of the multimedia teaching. Multimedia teaching is not simply to operate the computer or run the teaching software to show to the students. Teachers need to spend a lot of time and energy on collecting texts, videos, graphics and other materials which are relate with the class. And at the same time, the students' interest and hobbies are also should be thought. At last, the teachers
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summarize them and make the teaching courseware. In the application of multimedia teaching means, the teaching software must be appropriate for students and the teacher should play the role as the guider and the organizer truly.
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Some Disadvantages Existing in Multimedia Teaching
Because of the teacher always want to provide the students with more information, thus they often overvalue the ability of studying and put too much content in the courseware. As a result, the class aggravates the students' burden of handling the music information. In order to attract the attention of students, the teacher pays more attention on the changing of color and the graphic. It would distract the attention of the students, and they may feel visual fatigue and could not understand the content of the class effectively. At the same time, the way of teaching violates the purpose of multimedia assistant teaching, which makes the class teaching become a mere formality and could not to achieve the good teaching results. Because of the ability of some teachers is limited, they may just move the content from their lesson plan to courseware and manipulate the computer mechanically in the class. When the courseware is shown in a high pace, the students could not pay attention on everything. They may not understand the teacher's explanation clearly, then feel psychological panic and learn little in the class.
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Some Disadvantages Existing in Multimedia Teaching
Modern multimedia teaching method provides a new way of teaching and studying to teachers and students with its unique visual effect and interactive application, and it shows a very broad application prospect in music education. With increasing investment in higher education, the development of computer technology, we are convinced that multimedia teaching tools will make grate changes in the aspects of concept, content, means, methods of the traditional music education and teaching system. At the same time, it explores a new way for students to study music actively and creatively. In a word, modern multimedia teaching has very realistic significance in improving the efficiency and level of teaching, and it also plays an important part in realizing the modernization of music education.
References 1. 2. 3. 4. 5. 6.
Zhang, H.: Research on Higher Education 22(1), 64 (2006) Lv, C.Y.: Journal of Shandong Education Institute 133(3), 34 (2009) Sun, D.F.: Journal of Changchun Teachers College 22(1), 122 (2003) Pang, M.: Education and Vocation (24), 141 (2009) Jiang, H.M.: Fortune World (11), 100 (2008) Wang, W.Z.: The Science Education Article Collects (13), 137 (2009)
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7. Han, X.J.: Higher Education of Sciences (2), 74 (2005) 8. Wang, D.J.: The application of multimedia technology. Science & Technology Information (8), 12–14 (2011) 9. Xu, Y.P.: Using multimedia technology optimization music teaching. Forum on Contemporary Education (6), 18–20 (2010) 10. Du, P.Y.: The Research on multimedia technology in College Music Teaching Application. Public Communication of Science & Technology (8), 221 (2010) 11. Li, L.: The application of Digital multimedia technology in music the teaching. China Adult Education (7), 117–118 (2009) 12. Lv, C.Y.: On the Application of Computer Multimedia Technology in Music Education. Journal of Shandong Education Institute (3), 34–35 (2009)
Research on Cultivating Innovate Thinking of Environment Art Students Lili Cui School of Art & Design, Guilin University of Electronic and Technology, Guilin 541004 [email protected]
Abstract. Innovate thinking is the core of cultivating innovate capacity. This paper reasonable analysis a series of issues such as the common phenomenon of “poor quality of students”, “copy doctrine”, “Innovative thinking poor”, “weak rapid expression”. And the relevant solution is proposed to explore a new model for education of environment art. Keywords: Design of Environment Art, Teaching Method, Innovate Thinking, Rapid Expression.
1
Introduction
In recess, the author makes a research on the three major problems in learning in environmental art design with 225 students. Through the investigation, the result can be concluded by the table 1. Table 1. The distribution percentage of the three major problems of art and design students in learning Problem Number Percentage(%)
Hand-painted 165 73.3
Computer software application 102 45.3
Innovative thinking 144 64
Through the above table, we can conclude as follows: (1) The students generally felt that hand-painted, computer software application and innovative thinking are the three major challenges in learning. (2) The hand-painted is a major problem of the most of the students, the number is 165, share of the percentage of 73.3%; The second is innovative thinking, the number is 144, the proportion is 64%; The third is the ability of computer graphics software applications, the number is 102, its share is 45.3%. (3) Nearly half of the students thinking that the hand-painted, computer software application and innovative thinking are the major challenges they met in learning at the same time.
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(4) The distribution of three major problems accounting for hand-painted > innovative thinking > computer graphics software applications ability, it is conclude that most of the students pay more attention to learning computer graphics software. (5) The students the author surveyed are in third-grade, these students have completed basic education, and accepted some of the professional educations, at this stage, up to 73.3% of the students hand-painting is a major problem for them are abnormal, it is indicating that the most of the students’ basis are poor. To the designer, hand-drawn,computer skills and innovative thinking are both important. As an excellent environmental art designer, first should be with innovative design thinking, and then have a fast handing expression capacity to express the design thinking quickly and accurately, the computer-aided renderings expression are third. But the reality is opposite. Today, environmental art and design students are generally ignore the hand-painted training and innovation thinking, like plagiarizing, and pay more attention to the computer graphics. This situation is showing not only from the usual set operations demonstrated, more of a classroom performance and graduation of the students. And it is no longer about a student or some students but is a catholic phenomenon. For this phenomenon, we should analysis the causes and strive to find solutions to prevent it.
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Reducing of Students’ Quality
It is a potential entrance rule of that the science the first, the liberal the second, and the art the last. By the impact of the rule and the fact that art graduates would find the better work position and well paid, a large proportion of students turn to learn drawing and painting in high school, not because there are interests in this area, but for finding a way into university, just because the bad scores of cultural courses. Although there are some real art lovers, but that is small. The situation is really the reason of that the art students’ culture foundation is very weak relation to other students. And most of art students are quick entrance university with very short time training without the solid painting foundation, so it is very difficult to learn the professional knowledge after entrance into college. The quality of students can not be guaranteed even more with the impact of expanding enrollment. Faced with this situation, is our recruit models and structures of art students confronted with the fundamental form? This is what we should be thinking about.
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Ignore the Hand-Painted Training
For a designer, nothing is faster than hand-painted to record and express their design ideas, and communicate more easily with client. It can be said that a hand-painted skill is one of the most basically skills. But with the proliferation of computers and computer renderings of the popular aesthetic, students are busy learning a variety of software, and even spent a large amount of money to participate in a variety of software training
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courses in four years. Of course, the main reason is that students are drawing too much attention on the computer. With the rapid development of computer graphics and graphics software to improve and mature, all kinds of beautiful indoor and outdoor design renderings become a popular. For students, the over-emphasis on computer renderings also produced such an illusion that studying environmental art designing is just learning drawing software on computer, and only the ability of using the software skilled could lead to draw a variety of beautiful renderings, and to find a good job in the community. As a result, most students regard the learning of drawing software as an important task of environmental art design, and as the work must to be completed. In order to learn the software, they have spent heavily to the community up to attend training classes, and even took the laptop computer to classroom in class to play. As the thinking of some students, playing with drawing software is more useful than listening to the teacher. The students with skilled using of the drawing software also very have good sense of superiority, as if looking for a job after graduation has been no problem. Of course, it is had to be admitted that this is indeed an advantage in some ways. But as a designer of environmental art, just the skill of drawing is not enough. It turns to be a draftsman at best but the designer. Designers should first have a good design thinking and fast ability of expression, and only then they will express the mode of designing using their own design concept renderings. Many students have blurred this, they only focus on their own computer graphics capabilities, while ignoring their own creative thinking and rapid expression of abilities. So even if the computer graphics are relatively strong, but weaker in innovative thinking, the ability of quickly expression would be even bad. It is easily shown that without computer they can not complete the class work, and have no idea without reference books.
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The Weakening of Innovative Thinking
With the developing of network, it is easy to get the information such as a variety of domestic and foreign design information, best designer case. It is a benefit to share and learn the information through the internet, broaden the knowledge, and find inspiration of creative work. But it also brings some negative effects, that is, the spread of plagiarism. It should be said that the phenomenon happened in teaching of environmental art is not only one part, but is a general phenomenon in whole community. “Mainland copy the coastal, domestic copy foreign” by the impact of such unhealthy practices, students’ class works are copied, and graduation design works are plagiarism. And sometimes in the same course, same class, there will be more then three works are similar, which proves the common "resource sharing". The terrible result of this phenomenon is a direct consequence of the weakening of the students’ creative thinking, as always thinking about using other people's and have very little of their own things. This is a very dangerous phenomenon that no computer on the can not be completed without reference no idea and it must be corrected, or, there is only copied environmental art left several years later.
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The problem is widespread, and it is urgent to solve, how to develop students ability to express creative thinking and fast, it can be considered from the following aspect.
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Reform of Teaching Mode
First of all, the reform of teaching mode should adjust the subjects constitute of environment and art students. The structure of professional subjects should be integral and systematic, rather than vague, overlapping, otherwise students will prone to “professional not specialized” questions. The resolution could be considered specifically from the following aspects. 5.1
Enhance the Building of Learning Culture
It is mainly reflected in how to contain the “copy” and “plagiarism” as well in building the learning culture. This would requirements that all the related teachers must resolutely prevent and combat the phenomenon of plagiarism in peacetime. For graduation design, the relevant Bi-based defense mechanism should be completed and requiring teachers to really be fair, just, impartial, guide the graduate students strictly and resolutely stop the plagiarism, encourage students to do design by themselves. The students designed by them should get great praise, at the same time, the students with the copying behavior should be give a serious warning or the appropriate punishment. Then the phenomenon of plagiarism will be able to be stopped in effect after a period of work. 5.2
Hand-Painted with Equal Emphasis on Computer Skills Training
While in college, and more than a year before entered the university, the students are learning the appropriate color, drawing sand sketches, but that is basically to meet the test carried out, there is no clear relevance of learning. Students are not clear what is the relationship between the basically knowledge and their future professional work. So it does not pay enough attention from thinking, which could be proved by their usual class work. How to improve this situation, we need teachers of the usual course of instruction often show some of the excellent hand-painted design cases of the best designers to students to tell them the importance of rapid communication skills, and make them pay more attention from their ideological cause. The most important is that students usually have to train fast skills, such training should be clearly targeted. For example some quick questions and special subject can be designed with more cases, and explain the cases through hand-painted. By this way, the students would be trained with both the fast skills and creative thinking 5.3
Improve Innovative Thinking with Quick-Designing
The so-called quick question design is that within the specified time, giving students some topics with limitations, such as set design theme, region, and the using
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environment of products, so that they complete a certain design task. The feature of these kind questions is the “fast”. In the period of time, students should not only propose the designing case, but also complete certain degree of local design, and to express the drawing effect of the design. This kind designing requires students to have both a fast response capacity, design thinking, and also have good hand skills. And to make the ideal solution, students must usually see and collect more and more data information, enhance training hand-painted, so as to express the desired design effect. It should be said that the kinds of subjects is very effective for training the ability to creative thinking and fast express. So it should ensure that there is a certain amount of quick designing topics in every professional course. 5.4
Teaching Combined with Practice
Students should be encouraged to realize classroom training on topics, and analysis of its strengths and weaknesses as soon as possible. Practice is very important for the design profession students. Much knowledge learned in class is reinforced in practice, and environmental art students are no exception. So many students of the third grade at the university will be related to a variety of design practice, in order to gain practical experience, and even affect the expense of normal school hours. In this case, the teacher should not impose intervention, but should grasp this opportunity to encourage students to get classroom training on topics to do, and cooperated with students with advice to analysis the strengths and weaknesses, improve the design, helping students to complete practical tasks at the same time, and gave all students a vivid lesson at the same time. It would be the best combination of theory and practice because there are specific cases, the use of the specific population, the use of the environment, the specific application requirements. This kind of will benefit both teachers and students with the features of lively and practical. 5.5
School-Enterprise Integration, Give Students Opportunities to Practice
It is necessary to practice in society for students. But such opportunities are few, and will affect the students’ leaning at a certain extent. Now many university departments found the own design company using the own resources and advantages, providing a certain amount of practice opportunities and receiving certain economic benefits at the same time. It is worthwhile to promote. The resources of art and design professional are sufficient and should be used to form the relevant design company with indoor design and outdoor design to provide the students with opportunities to practice. It will be very helpful for their future employment to use their theory in the classroom knowledge into practice.
6
Summary
Environmental art and design is a subject combined with science and art. As an environmental designer, it is not only required to master the computer graphics
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technology, but also the innovative design thinking and rapid hand skills. But now environmental art and design education are generally heavy technology, light theory, heavy computer and light hand-painted. So the best environmental art designer still extremely scarce, although each year a large number of environmental art graduates year by year and the job market becomes saturated. Our environmental art and design education is impunity for their responsibility for the formation of such a situation. And to fundamentally change this situation, the relevant departments carry out the education policy on science and art, theory and technology synchronization, increase the professional recruitment threshold for environmental art students, and improve the building of style of study. It will be a good solution to training the creative thinking of students in teaching mode and combining theory with practice.
References 1. 2. 3. 4. 5. 6. 7. 8. 9.
Wang, Y.: The Thinking of Education System and Teaching Purposes on the Current Design. Art Garden (6), 63 (2002) Ma, S.: Designed to Reflect China’s Higher Arts Education. Art Garden 3, 22–23 (2002) Wang, Y.: Discuss the Reform of Environmental Art and Design Teaching. Economic & Trade Update 11(5), 193–194 (2007) Li, S.: To talk about several issues of design education in China. Decoration 8, 24 (2002) Zhang, Y.: Transform the Key of Designing Education. Art Panorama (6), 78–79 (2005) Liu, C.: The Teaching Model of Environmental Art Design. Arts Education (02) (2010) Jiang, J.: Vocational Schools Reaching Art and Design Environment for Reform. Institute of Jiangxi Blue Sky (02) (2009) Guo, C.: Reform of Environmental Art and Design Teaching. Knowledge Economy (12) (2011) Shi, S.: Model of Environmental Innovation in Teaching Art and Design. Academy (10) (2010)
Information Specialty Experiment Remote Tutor System Development and Application Xiu Hui Fu, Li Ping Fan, and Shu Li Ouyang Shenyang University of Chemical Technology, China [email protected], [email protected], [email protected]
Abstract. This paper analyzes that traditional remote experiment teaching system suffer from weak interactive functions. Combined with the characteristics of the remote experimental teaching mode, this paper developed interactive information specialty experiment remote tutor system. First of all, according to the current situation of Information specialty, the remote tutor system teaching model is given. Second, the remote tutor system composition is introduced, the database, experimental site and multifunctional interactive system establishment method is given in the system. Finally, it has obtained a good teaching effect in the experiment teaching process. Information specialty of the remote tutor system has the certain reference significance for general discipline remote experiment system development. Keywords: Interactive, Simulation experiment, Remote tutor.
1
Introduction
Information specialty experiment is a basic course to cultivate students' practice ability, but the traditional guiding the experiment teaching is not conducive to the improvement of teaching quality because of means of a single. Domestic and foreign universities are in more experimental teaching reform and laboratory construction force, concise high quality experiment teaching resources, develop the experimental teaching website, improve the quality of experimental teaching, improving the students' practice ability and innovation ability training level[1-4]. Make full use of network resources, bring the multimedia technology into the experimental teaching become hot spots in home and abroad some colleges in recent years[5-7]. Development interactive information specialty experiment remote tutor system has the positive role, to change the subject status of the teaching and learning, and to increase the students' interest to the information specialty, the cultivation of students' autonomous learning and inquiry learning etc. At present, the development of the experimental teaching site is primarily served as the functions of the repository [8-13], interactive function is not strong, general have no simulation experiment function. With the support of Liaoning province higher education reform project and Shenyang University of Chemical Technology education reform project, task group
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develop interactive information specialty experiment remote tutor system, this paper mainly introduces this system.
2
The Experimental Teaching Mode of Interactive Remote Tutor System
The traditional information specialty experiment is own systems of enclosed teaching, students just passively receiving knowledge. Experimental teaching materials are almost the only reference books for students, students not only see equipment but also communicate with the teacher before experiment. Although it is a open laboratory, but open time is limited. Most is the teachers work time, and this time most of the students are in class. Students can only rely on single experimental teaching materials to choose the experiment and preview the experiment. Such an experiment that is dull and boring, greatly restrain students interest in the experiment and the development of personality. Experimental teaching based on Interactive remote tutor system, can break through the experiment limited by time and space, form multielement open teaching environment, and realize the real time, space, content and method overall open. We construct interactive information specialty experiment remote tutor system, compared to the traditional distance teaching system has unique function of simulation experiment and interactive test evaluation through the remote network.
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Interactive Remote Tutor System Establishment
Interactive remote tutor system provides rich resources of learning and effective way to learn for experimental teaching information profession. The system is divided into experiment counseling site, multi-function database, interactive test system three parts. As shown in Figure 1. 3.1
Multi-function Database
Material database established .Acquisition research apparatus and instruments parts, match with pictures voice, text introduction, so that students in a preview, the use of the instrument have perceptual knowledge. Record experiment principle explained and experimental demonstration, emphasis on matters of attention in the operating process etc. video material, make the students understand the points for attention of experiment, clear test principle, experiment, experiment content and the steps method, etc. through the web site provides information, before experiment. The establishment of the preview examination database .According to knowledge the student should know, understand after preview, we establish experiment examination question database to preview. Students can choose your own test, through scores which they get from test yourself questions, to test his experiment preview. Teachers can use experimental preview database to examine the students.
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The theory virtual simulation demonstration database established. The theory virtual simulation demonstration main program frame design and production, all photos and audio, animation, audio introduction are designed by Authorware[14], Flyvideo used for video animation catching[15], Animator used to the clips and processing and animation audio processing[16], Photoshop used for some pictures and words of processing, Visual C++ used in the compilation of the part program. Through the experiment principle virtual simulation demonstration, the theory that difficult to understand is made easy to understand, it also can reduce the difficulty and improve the preview the learning interest of the students.
Fig. 1. Interactive remote tutor system
3.2
Interactive Test Assessment System
The realization of the remote interface using TCP/IP protocol, use Visual C++ programming realization. Extracting test questions from test question database, automatically judging the answer of answers right or wrong, and giving the result functions are using Authorware to realize. Through the Visual C++ program Authorware software called, realize the remote interactive experiment preview test. The experiment results is composed of three parts, they are preview performance, operation results, report results. In the past, preview performance is to see the preview
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report wrote complete or not to give points, have a large degree of one-sided. Through the experiment preview test system, random combine a test from preview the test question database, for the assessment of the previewing the effect.index. 3.3
The Experiment Counseling Site
The interface routine of laboratory tutorial network station client user is designed by Visual C++ and JSP.NET, while IIS(Microsoft Information Server is adopted in WEB server as its application program, server program is designed by JSP.NET, and SQLserver2000 is adopted for Database Design. Students can through the network resources, understand the historical background and the instruments and equipment in modern industry and scientific research on the application of the purpose of the experiment, do simulation experiment according to the software provided by website, can understand the whole process of before the experiment. Especially for difficult experiment, can explain and illustrated by watching video demo, easily solved the difficult problems. Students can check their own preview by doing the experiment preview test question database problems. Students can set the problem to a teacher through the form of leaving a message, teachers can use the same way to answer the problems of students. Such a common problem was solved login the campus net. The use of network resources to enhance students' to information specialty of experiment interest, to reduce the difficulty of the preview, to supervise and check the preview, improve students' information profession experiment teaching method, to change disadvantage that students can only busy tested set of data in difficulty bigger experiment and not focus on understanding the use of instrument analysis method and its functions. To improve the students' experimental skills, improve the quality of experiment teaching, and guide students to use the instrument correctly, reduce the instrument equipment damage rate and extend the service life of equipment has the vital significance.
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The Application Experiment Teaching
Interactive information specialty experiment remote tutor system is made according to the actual our school experimental teaching. In experiment teaching, most of the students complete preview with it before experiment, in the experimental process specifications, greatly reducing the blindness. And part of students will demonstration of the video download to cell phones or MP4, before experiment or operation process a video demo, see clear experiment process makes experiment successfully completed. After the experiment, student can also check the example of the data processing and the error analysis, etc. In short, there is such a experimental guidance system, The students preview the experiment with it before class, feel to have the effect very much ,can actively discusses related issues with the teacher after experiment class. Experiment teachers believe that did the students use the software,
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reduce the operation of the lot of blindness in experiment class, teaching quality is remarkably improved. After the completion of Interactive information specialty experiment remote tutor system .Level 2008 automation specialty, measurement and control professional five classes use the system and electrical engineering, electronic information professional five classes do not use this system. We can compare the results of the user and not the user. Table 1 is All the link performance rate contrast table. Table 1. All the link performance rate contrast table
Experimental link results The class use system The class do not use system
Preview excellence rate
Operating excellence rate
Report excellence rate
Grade excellence rate
49.2%
54.7%
43.6%
50.5%
40.7%
23.1%
27.6%
27.4%
From the comparison results can be seen, compared to the student who using remote experiment guidance system and not using remote experiment guidance system, not only the preview the results is high, but also operating excellence rate result and the achievement of the report excellence rate are greatly improved. Table 1. is all the link performance rate contrast table.
References 1. Wang, J.: Experimental Technology and Management 25(1), 110–111 (2008) (in Chinese) 2. Li, M.L.: Knowledge Economy and the Unbalanced Development of Higher Education (1), 45–49 (2000) (in Chinese) 3. Pan, L.: Experimental Technology and Management 24(9), 131–133 (2007) (in Chinese) 4. Dong, G.Q.: Laboratory Research and Exploration 24(6), 93–99 (2005) (in Chinese) 5. Hang, D.P.: Science and Technology Innovation Herald (2), 169–170 (2010) (in Chinese) 6. Jin, Z.Y.: Laboratory Research and Exploration 26(1), 124–125 (2007) (in Chinese) 7. Zheng, Z.Y.: Modern Educational Technology 15(5), 46–50 (2005) 8. Clem, P.G.: Foreign Science and Technology Trends (3) (1998) (in Chinese) 9. Liu, X.O.: Experimental Technology and Management 16(11) (2007) (in Chinese) 10. Chen, H.Y., Chen, X., Yin, H.Y.: Laboratory Research and Exploration 25(2), 194–197 (2006) (in Chinese) 11. Canfora, G., Daponte, P., Rapuano, S.: Remotely accessible laboratory for electronic measurement teaching. Computer Standards & Interfaces 6, 489–499 (2004) 12. Baran, J., Currie, R., Kennepohl, D.: Remote instrumentation for the teaching laboratory. Journal of Chemical Education, Easton 81(12), 1814–1816 (2004) 13. Wang, H.Z., Cheng, H., Yao, J.: Development of Internet Based Remote Process Control Laboratory. Research Exploration in Laboratory 28(7), 72–74 (2009)
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14. Li, X.Q.: Design and application of Authorware teaching website. Journal of Nanchang College of Education 26(3), 71–72 (2011) 15. Dong, X.H.: Research and Design Assisted Instruction Website of Resource-oriented Curriculum Unit. Computer Knowledge and Technology 6(4), 909–911 (2010) 16. Ding, X.H., Wu, C.: Design and Realization of Flash Teaching Website Based on B/S Model. Computer Study (3), 16–18 (2010)
Research on the Model of Practice Teaching Base on Project Driven Teaching Xiu Hui Fu and Li Ping Fan Shenyang University of Chemical Technology, China [email protected], [email protected]
Abstract. The effective of the project driven teaching can be proved in the improvement of interest in learning the theories and practices, the development of self-learning ability and the enhancement of innovation at home and abroad. Previously, project driven teaching has been used in a course or a type of experiment mainly. There has no research or application of a subject reported till now. Aiming at the undergraduate education of information specialty, based on the application of project driven, this article does a series of researches on the teaching model. For the project planning methods, the practice teaching of information specialty can be planned for some projects of difference types, and the link of various projects has been researched; Coming out the integration method of laboratory equipment which is adapt to project driven teaching; Finally, the evaluation method is given by the implementation of project driven method in the experimental teaching. The effective of the project driven teaching is verified in professional practice teaching by the practice of undergraduates whose professions are Department of Measurement Technology and Instrument of Institute which belong to Information Science and Technology. Keywords: Project Driven, Practice Teaching, Teaching Mode.
1
Introduction
In the early 20th century, John Dewey who is American famous pragmatist philosopher and educator proposed that people could not acquire knowledge by passively listening or reading, this means that knowledge should be acquired by practicing. He believed that teaching not only enable students to gain experiences but also should make the students’ experiences constantly transformation and growth. Students learn how to gather information and find the problems by participating in a lot of activities, at last propose the way of solutions to problems and test its validity and feasibility in practice [1]. Project-driven pedagogy has been widely used in Germany, Japan and other countries[2-4], The implementation of the method greatly mobilize the students’ enthusiasm[5], so that students can understand the joy of success in the process of implementation of the project, and a part of projects are completed by a team, this requires active participation of team members, members need cooperate sincerely, democratic consultation, full discussion and the right
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decisions to ensure the successful completion of the project, thereby develop the students’ cooperation capacity and teamwork spirit[6]. Project-driven method in our country is mainly used in vocational and technical schools and part of practical courses of universities, and achieved good teaching effect [7-11]. If the project-driven method is researched and applied systematically in a particular subject, then the problems of laboratory equipments need to be solved, the traditional curriculums also need to be reformed, the requirements of teachers and the level of management are higher, so there are no relevant reports by now. For the training of comprehensive talents who can master the mechanical and electrical measurement and control, and other subject technology, research on the model of project-driven in the practice teaching of information profession is very significant, some theoretical and practical guidance are also provided for project-driven method which is for interdisciplinary research and application. This article is subsidized by higher education reform project of Liaoning province and the education reform project of Shenyang University of Chemical Technology, the reform of experiment teaching model of information profession in our school are summarized base on project-driven.
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Project Planning and Integration of Laboratory Equipments
2.1
Project Planning
The practice teaching of information profession can be divided into three categories according to the project: Basic skills training project, professional skills training project and integrated application project. It can be shown in Fig.1.
Fig. 1. Project categories
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Each type of project has been planned a number of subproject by teaching plan of information profession. For example, basic training program include design and manufacture of the body of mobile robot, design and processing of intelligent instrument case, design and manufacture of circuit board which is based on the smallest system of single-chip, and other subprojects; Professional skills training project include design of electronic scale, temperature closed-loop control , flow closed-loop control and other subprojects related with professional direction; Integrated application project include mobile robot system, intelligent flowmeter and other integrated subprojects. The research of the links between different levels of projects, for example, intelligent robot project which is belong to integrated project, in the phases of basic skills training project, in addition to complete the basic skills training which is necessary for class of measurement and control, the manufacture of robot case and circuit board are also must be completed; in the phases of the professional skills training project, in addition to complete professional skills training which is necessary for class of measurement and control, the design of intelligent robot sensor , conditioning circuit , the design and debugging of hardware and software of computer control system are also must be completed; in the phases of integrated training, the key is control algorithm, the implementation of the intelligent robot movement by trajectory planning and implementation of complex tasks; as the example of intelligent instrument project of integrated project, in the phases of basic skills training project, the design and manufacture of structure belong to instrument and the manufacture of circuit board are also be done; In the phases of the professional skills training project, the design of intelligent instrument sensor, conditioning circuit , the design and debugging of hardware and software of computer control system are also be completed; in the phases of integrated training, the instrumentation ,sensors and controllers are combined integrally, then achieving the project of intelligent instrument which is related with engineering, completing instrument calibration and applied in practice. Full pay attention to the link between project classes, the relationship between each subproject and integrated project must be clear, it can enhance students' work enthusiasm for subproject, by the completion of each subproject, finally achieving the integrated project, and reduce the difficulty of achieving an integrated project. 2.2
Integration of Laboratory Equipments
Laboratory equipment of information class profession is integrated according to the project class. For basic skills training project, three platforms are formed. The production platform of mechanical components is formed by small multi-function lathes, drilling and welding, so that each student can carry out the processing of basic structural components, instrument case , robot body ,and other works can also be designed and produced; The production platform of circuit board is formed by the engraving machine, laminator and other components, the production platform of electronic circuit board used for soldering electronic components, so that students can carry out the design and production of double-sided printed circuit board, therefore,
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the welding of electronic components can be completed skillfully; The control system debugging platform is formed by the multimeter, oscilloscope, multi-function calibrator and other components, enable students to use the debugging equipment skillfully, the debugging of complex automatic control system can also be done. Professional skills training project, hardware system consists of a small flow closed loop control device, temperature closed-loop control device , vibration device, eddy current distance unit, weighing device of strain sensing, the characteristics of differential transformer test device, graphics processing unit and other variety of engineering objects installations, each device is equipped with a industrial sensor and standard measuring instrument; The common control platform is set up by the data acquisition card and PC, engineering objects can be measured and controlled which base on virtual instruments or configuration software. Integrated application project, hardware system consists of a small wheeled robot and the integrated design unit of intelligent instrument which turns in the direction of structure (Each unit consists of conditioning board, display board, case, and power supply boards). For the small wheeled robot, each is equipped with ultrasonic sensor, infrared sensor, antennae sensor, color sensor and encoder, so that a variety of measurement and control tasks of robot can be achieved; the integrated design unit of intelligent instrument which turns in the direction of structure, the development and design of intelligent instruments can be achieved which turns in the direction of actual projects. The integrated design and practical ability of students are improved by guiding students to participate in robot competition, "Challenge Cup" competition, the actual projects of teachers and other projects.
3
The Application of Project-Driven Method in the Experimental Teaching
3.1
Implementation Methods
The implementation of project-driven experiment teaching can be expressed in the following areas. The first part is the project preparation. When the "project-driven" is used to teach, first, teachers should arrange experiment project which belong to corresponding the course, the stage and the unit, require students to carry out experimental with the projects and the problems. Inspire students' interest in learning and motivation by exploring issues, fully mobilize the operation enthusiasm of students by teachers’ guides. The second part is the project analysis and operating experiment. Enable students to discuss and analyze the project after the project is proposed, the completion of project needs something to be done, in other words, propose questions. On the basis of this, teachers summarize and generalize the analysis of the project, clarify and confirm the projects that the students need to be done. Then give the students plenty of operating time, make the students to try as possible as they can, enable them to
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experience, feel and comprehend the process in the operations, at the same time, discover and solve problems. The last part is the exchanges and discussions, evaluation and summary. At this point, students should be brainstorming, developing ideas, encouraging innovation, on the basis of teachers’ comments, find vulnerabilities and perfect flaw, explain some of the difficulties and focus which are common, and master the knowledge or the law of one thing, and then infer the knowledge or the law of the same things, a large number of application examples are given, further enhance the understanding of the knowledge that the students have been learned. Carry out some popular discussions as much as possible, then works display and method communication should be done, make students to get some inspiration on the idea, motivate students' interest in learning. 3.2
In Evaluation of Project Learning
In the project-driven teaching, learning effect can be measured mainly by the quality of work related with the completion of the project, this part mainly include teacher evaluation, study groups evaluation and self-evaluation. on basis of the process of project design, project analysis→task decomposition→learning of knowledge point→application of knowledge points→construction of target→combination of target→completion of the project, in above activities, by the interaction between teachers and students and mutual collaboration between students, then examine students' understanding for project tasks, the learning and understanding of knowledge point and training the ability by the application of project design with appropriate development tools. The ultimate goal of the project learning is the conversion of knowledge into ability. Topics of project content→project analysis→task decomposition→learning of knowledge point→application of knowledge points→construction of target→combination of target→completion of the project, in this series of teaching activities, the role of the teachers become students’ partners in learning from the role of the imparting of knowledge. 3.3
Application Effect
In 2008 , Institute of Information Science and Technology completed hardware integration according to the project classifications, and the profession project of information was established, the experiment teaching of project-driven is carried out to undergraduates whose professional are Department of Measurement Technology and Instrument of our institute. After the training of the basic skills, professional skills and the project of comprehensive application, in the respondent of undergraduate graduation of 2011, every student took out the complete works of their own design. In the extracurricular practice of project-driven model, 80% of the students whose professions are department of measurement technology and instrument participated in various scientific and technological activities. From 2009 to 2010, there have been nearly 10 students wined the awards in all kinds of robot competitions, nearly 40 students received training by participating in the competition; at the same time, many
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projects of students received the right to set up projects which was funded by university innovation projects of the province.
4
Conclusion
The establishment of project content is the basis of implementation of project-driven method, in the selection of the project content, according to the characteristics of the students’ cognition, full analysis must be done according to specific requirements of application of technical skills with the professional of information class, and analyze the relationship of the courses that were given before and after, from simple to complex, gradation is distinct, the planning should be scientific and rational. The settings of project not only combine the theories and practices of the teaching content, but also stimulate students’ interest in learning, the completion of the project is harder than the instance which the teachers explain, other subjects should be combined as much as possible, and there must be some comprehensiveness. In the process of project-driven experiment teaching, the dominant position of students and the counseling role of teachers must be played fully, it is necessary to guide the students carefully in the implementation process, make them understand how to discover, to think, to find solutions of problems; summary and guidance need to be done timely after completion of the task, encourage students to ask questions, solve problems by themselves. Finally, the assessment criteria must be clear, and the completed work can be evaluated. After learning, teachers and students summarize together, and the project content can be extend, this can meet future needs. Project-driven method is verified that it is very effective for improving the students’ practical skills and enhancing the capability of innovation by the practice of undergraduates whose professional are Department of Measurement Technology and Instrument of Institute of Information Science and Technology.
References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
Luan, J.H.: Vocational Technology 90(2), 42 (2008) (in Chinese) Ma, L.W., Qi, W., Zhong, G., Zhi, Y., Ji, S., Jiao, Y.: (261), 54–55(2007) (in Chinese) Liu, B.X., Wu, Q.Q., Zhong, G., Zhi, Y., Ji, S., Jiao, Y.: (261), 51–52 (2007) (in Chinese) Wang, L.R.: Vocational and Technical Education 30(19), 83–87 (2009) (in Chinese) Li, L.L., Li, C.: Computer Knowledge and Technology 5(28), 7991–7992 (2009) (in Chinese) Chen, X.B., Zhang, Y.J., Wang, W.H.: Computer & Information Technology (12), 105–106 (2007) (in Chinese) Bi, G.F.: Science and Technology Tnnovation Herald (10), 159–160 (2010) (in Chinese) Chen, X.Y.: Computer Knowledge and Technology 6(6), 1360–1361 (2010) (in Chinese) Qiu, Y.J., Zhang, H.F.: Computer Knowledge and Technology (4), 84–99 (2010) (in Chinese) Huang, X.L., Duan, F.Y.: Research and Exploration in Laboratory 25(3), 279–286 (2006) (in Chinese) Zhang, M.: Research and Exploration in Laboratory 29(9), 89–91 (2010) (in Chinese)
The Discussion on the Teaching Reform of the "Electromagnetic Fields and Electromagnetic Waves" Based on "Field Techniques" Yinpu Zhang, Yanchun Shen, and Minglin Yao College of Tangshan, Tangshan, Heibei, China {Yinpu Zhang,Yanchun Shen,Minglin Yao,zhangyinpu0629}@126.com
Abstract. The "electromagnetic fields and electromagnetic waves" is the theoretical basis based on the "technical field" with abstract nature related to the follow-up courses. Focus on the characteristics of difficult teaching and learning, this paper starts from the professional status and role of this course. Guided by the advanced teaching philosophy, it sets the course content as an opportunity, and proposes the education reform ideas from the two aspects of theory and practice teaching. Through teaching practice, it promotes the learning and teaching of the electromagnetic theory and improves a new starting point of creativity of the students. Keywords: Field Techniques, Curriculum Reform.
1
Theoretical
Teaching,
PracticeTeaching,
Introduction
The recent development of the modern science shows the "electromagnetic fields and electromagnetic waves" is the growing point of some cross-disciplinary subjects and the basis of the development of new emerging interdisciplinary subjects. The rapid development of natural science in the 21st century, such as: the high voltage transmission, microwave communication, optical fiber technology, nuclear magnetic resonance, electromagnetic compatibility, the stratum electromagnetic imaging, and other technologies have been generally realized. The electromagnetic field theory provides strong guarantee for the development of these applications based on the "technology field".
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technology basis, the antenna technology and design, the microwave devices and the design, the RF communications, WiMAX theory and its application, the EMC technology, sensing technology, and so on. Through this course, students can learn the "field technology" systematically that is different from the "road technology" for the first time. On the basis of the ordinary physics electromagnetism course, students can master further of the basic laws and fundamental nature of the electromagnetic field, and the electromagnetic wave theory, know the main application areas and its principles of the macroscopic electromagnetic theory which will lay a foundation for the related follow-up courses of the communication systems. This course can not only make students master the basic theory of the "field technology", but also train their ability to analyze and summarize problems, use the field theory and the wave theory to analyze and solve practical problems, and become the only way to cultivate the talented people with high practical ability in communications profession, high-quality in sustainable development, and with high skill, in order to meet the needs of the related future works of the students after graduation.
3
The Course Content
Fig. 1. Electromagnetic fields and electromagnetic waves curriculum
The basic structure, theories, concepts and formulas (such as gradient, divergence, curl, Maxwell's equations, etc.) related to this course needs not only to be discussed, it must take time and effort to clarify thoroughly. The knowledge with practical value for the future work (for example, the wave equation, transmission line theory, electromagnetic radiation, etc.) is to be discussed well. For the contents need large amount of significant mathematical knowledge, it should let the students derive after class. The contents have not so close relation with the whole knowledge context are to be avoided.
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The Reform of the Teaching Courses
Nowadays, most courses in many schools have the problem of class time compression, how to improve the quality of teaching on this basis worth our thinking. Teachers should adjust the teaching ideas, and design the teaching process carefully. The teaching reforms of our discussion group conducted on the theory and practice teaching are as follows: 4.1
Select Well of the of Teaching Content and Lay Down New Teaching Programs
Delete the content that is duplicated from other disciplines The "electromagnetic fields and electromagnetic waves" is mainly teaching the static field, dynamic field that is the movement rule of waves, and its teaching content has not changed for ten years. Therefore, the main problems are: too much theorem in the content, the derivation proves in the formula and the skills of the analytical method, which has unnecessary duplication with the contents in the university physics electromagnetism subject. Therefore, it is the key to lay down new teaching programs. In the teaching arrangements, delete the duplicate contents, or let the students learning by themselves, play fully of their initiatives, add the discussion of the project cases to stimulate students' interest in learning, and reduce the repeating contents between courses. Re-optimize and Combine the Knowledge Structure For the section that is not only repeating but also related, break the original boundaries to re-organize and teach, and make it become a knowledge framework that can be accepted by the students. For the contents that are easy to be understood, leave them to the students in the way of outline. By learning by themselves, they can exercise their self-learning ability. This keeps the relatively systematicness between disciplines. 4.2
Teaching Methods
The teaching methods are the basic means to achieve the aims of education, and complete the task of teaching, which play an important role in the success or failure of teaching, and the intellectual development of students. The teaching is the bilateral activity composed by teachers and students, and it must adhere to the idea of "student-centered, and teacher-led". Especially, as the extremely difficult course, the "electromagnetic fields and electromagnetic waves" must focus on the initiative role of students. Only by a variety of active and mental activity of students, can they change the book knowledge into individual knowledge and be the creative knowledge. This process can not be replaced by any one, and must be completed independently by the students themselves. However, this process is not spontaneous which must be guide and inspire by teachers.
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Teach Well of the Introduction Class When teaching the "electromagnetic fields and electromagnetic waves", the introduction class should teach the development process of the electromagnetic theory---the classical electromagnetic theory phase and the calculation of electromagnetic theory phase, and give the general theoretical frameworks of the two stages, the important technology results and typical representative and so on. An important content in this process is to explain the contribution and achievements of Chinese scientists, and their current position in the world. Thus, in order to cultivate the patriotic enthusiasm of students and stimulate their interest in learning this course. The actual application of this course in the project should also be given when teaching this course. . For example, refer to the magnetic levitation train, stealth bombers, the antenna in the mobile phone applications and its radiation on human body, the principle of the microwave oven heating works, and so on. These can enhance the motivation of students to learn this course. The Formula Derivation should Focus the Physical Concepts Fully The necessary formula derivation should focus on the ideas and methods to teach analysis and solve problems. For example, in explaining the Maxwell equations, teachers should explain fully of the physical meaning of the total current equations, electromagnetic induction theorem, the flux continuity equations and Gauss' equation. Adopt the Cases Teaching to Stimulate Students’ Interest in Learning When teaching, teachers should combine teaching with practice, and give the specific application of related knowledge. Such as, when explaining the concept of polarization, teachers can tell the students as the television antennas sends horizontal polarized wave, the antennas should adjust to the height that is parallel to the ground. When teaching the problem of electromagnetic compatibility, teachers can refer the example of the 1982 British-Argentine war. As it did not solve the problem of electromagnetic compatibility, it caused lessons of the British warship sunk by wave of missiles. The Combination of the Heuristic Teaching and the Traditional Teaching Students must be asked to master some important contents (such as vector analysis) in the courses, while the heuristic teaching should also be emphasized. For example, when teaching the Maxwell's equations, teachers should summarize the Coulomb's law, Biot - Savart law and Faraday's law of electromagnetic induction that is taught previously, and point out the existing contradictions to introduce heuristically the concept of displacement current, in order to get the famous Maxwell's equations and predict the existence of electromagnetic waves based on this. The Guiding Discovery Method Propose question: no antenna and radiation system can radiate the "wave shape" of uniform plane wave, while people still set the uniform plane wave as a guide entry, why? Start from this point, teachers can inspire students in many aspects: the scientific way of thinking. How to create the physical model that is fully create full physical model and dose not loss its physical nature?
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The flexible thinking. We do not discuss the generation of the plane wave, but to discuss once this kind of wave is established in the infinite space. Dose it can be existed continuously, and in what way can it exist? Adopt the Comparative Method Conduct the multiple summary of the theorems, definitions and formulas with similar structure (such as the divergence and curl comparison of the vector, the characteristic comparison of the electrostatic field and the static magnetic field in the vacuum, the comparison of the electromagnetic field characteristics in the medium, and so on), list the table, and compare the similarities and differences, so as to deepen students' understanding and memory of the concepts. 4.3
The Reform of Teaching Methods—Relying on Digital Learning Platform
Fig. 2. Digital teaching the basic framework of the platform
The Proper Usage of the Multimedia Teaching Tools Learning the electromagnetic field has a strong spatial imagination ability, the abstract thinking ability, and logical reasoning ability, and is taken as one subject that is hard to teach and learn. When teaching, teachers can use video to present the electric intensity E in the coaxial cable, the space distribution and the video animation
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of the pulse in the transmission line; the reflection and transmission of the plane wave in the interface. These video demonstrations are useful to explain particular electromagnetic field conception, especially when time and space is involved; use multimedia presentation can show the movement of wave, change the abstract into concrete, and reduce the degree of difficulty. With vivid courseware, students will be more interested. The Effective Complement to Traditional Teaching Methods While, as the large classroom informative and fast progress of teaching, students are in a continuing state of tension, but lack time to understand, digest, and absorb, which has become a phenomenon that can not be ignored. Therefore, how to complete the teaching task with quality in the limited period of time, which can not only mobilize the enthusiasm of study of students, but also reflect the advantages of multimedia. It is the primary problem that should be solved if we use the multimedia courseware to teach. For this, when explaining important formulas, theorems and derivation, we can use the courseware to clarify the ideas quickly, then to discuss little by little, and write on the blackboard to deduce with students. 4.4
Introduce the Teaching Practice into Classroom
Introducing the teaching practice into classroom means to introduce the typical virtual experiments into the classroom, which realizes the simulation experiments through some software and virtual instruments in the computer. This can not only verify the teacher's classroom theory to deepen their impression of classroom knowledge, but also narrow the gap between students and textbooks, deepen their perceptual understanding to the electromagnetic field, eliminate the fear of students, and also improve students’ interest of learning in class.
5
Relationship between Innovative Culture and Local Culture in Local Undergraduate Course Academies
Footing on serving local development and construction, it is inevitable that when forming its own university culture, local undergraduate course academies are bound to be influenced, referenced, and dependant on local culture. [11]The forming of university innovative culture can not be separated from local culture. This is embodies in the following aspects. 5.1
University Culture Is the Accumulation and Crystal of Local Culture
Local undergraduate course academies are located in local area, to serve the development of local economy and society. It is absorbed in local culture. [12]And its culture takes root and grows in the inter-exchange among university, industry, and society. Rich local culture provides broad space for cultural heritage and development of local undergraduate course academies. It is the background and platform for the
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construction of university innovative culture, the soil for the existence and development of local universities. 5.2
University Culture Is the Beacon and Leader in Local Culture
University is an educational institute, as well as a cultural institute. It is the leader and foremost drive for the construction of local culture. Via the studying local culture, dialectically analyzing local culture, university can then lead local culture. University culture is hidden in university, and spreading beyond university. Culture created in university is not limited within the boarders of university. It has become the advanced culture that can lead the society. [1] In America, there is a saying that “First came Harvard, and then America”. In Germany, the famous Berlin Humboldt University created the splendid culture for Germany. Hegel, Feuerbach, the great thinkers who promoted the progression of history, once studied or taught in this university.[13]
6
Thoughts on the Construction of Innovation Culture of Newly Established Local Undergraduate Course Academies
The fundamental mission of newly established local undergraduate course academies is, footing on local, nurturing high quality comprehensive development high level talents, serving local economic and societal development. Constructing university innovative culture is on the immediate agenda for integrating and optimizing educational resources, enhancing operation level and education quality, and upgrading university culture contents. 6.1
Wake up Cultural Awareness, Raise Cultural Consciousness
Fei Xiaotong points out that, cultural awareness refers to giving sufficient attention to the function of culture, on the basis of clearly understanding human culture and university culture, wake up the consciousness for self development, to select, carry on, and innovate scientific and researchable culture, and engender the inner need for university culture construction, and continuously uplift potential for self development. [2]This requires that, every main body of a university, regardless teachers or students, everyone should have sufficient recognition on the importance of cultural construction for university, and devote in personal dedication to implement in reality, and thus form huge spiritual force, and become drive for university innovative culture. 6.2
The fundamental task of universities is to educate people, further perfect innovative system, with people development as the essence, reform the talent nurture mode from singular to complex and multilateral conversion. Break the singular teaching culture, construct teaching mode with nurture objective as main body, societal needs as
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guidance. Combine university innovation with market. Hold innovation as the principle line, establish financial management, human resource allocation, reward and punishment system with incentive as drive. Encourage innovative system guarantee, respect the main body feature of people. The design of system should reflect more with people orientation. Encourage innovation, and be tolerant to failure. Create a flexible systemic environment. 6.3
Increase Investment in Innovation, Reinforce Material Guarantee
The process of innovation, is a process of continuous exploration. Universities should increase investment in innovation, path solid foundation for innovative teaching. Initiate innovative activeness of the teachers and students, and offer conditions for students to implement innovative practice, by means of opening innovative education course, constructing innovative practice site, promoting tutor system, etc.. Encourage the students to apply for invention patent, promote results conversion, strengthen students’ ability to innovate, initiate entrepreneurship, and find jobs.
References 1. Xu, Q.: University Culture and University Spirit. Journal of Tianzhong 21(6), 119–120 (2006) 2. Ming, L., Zhang, X.: Newly problems in the construction of innovation culture and Countermeasures. Journal of Yunnan Finance & Economics University 25(3), 128–130 (2010) 3. Shi, L.: University Culture and the University Core Competence. Journal of Yancheng Institute of Technology 23(4), 67–70 (2010) 4. Zhang, S., Zhang, Z.: Core Factors of Core Competitiveness in University. Journal of Shanxi College for Youth Administrato 19(4), 93–95 (2006) 5. Wu, S.: Innovation and personnel training of university reform and innovation of mechanism. Innovation 33(5), 115–117 (2011) 6. Zhang, Z.: Innovative Training Model. CO-Operative Economy & Science 419(6), 116–117 (2011) 7. Xiao, H., Zhang, S., Deng, S.: China’s Innovative Thinking Training. Contemporary Education Forum (5), 58–60 (2011) 8. Chen, X.: International comparison of innovative talents’cultivation of higher education and the implications. Journal of Chongqing Education College 24(2), 128–131 (2011) 9. Cheng, P., Peng, Y., Wang, H.: Of our colleges and universities more innovative training model Pondering. Science and Technology Innovation Herald 9, 142–143 (2011) 10. Chen, T.: Colleges and universities to enhance education on innovation and thinking. Journal of Zhoukou Normal University 28(1), 116–117 (2011) 11. Zou, F., Yu, L.: Innovative Education for the current problems facing the thinking. Education for Chinese After-school 12, 14 (2010) 12. Gao, Z., Kang, J.: Colleges and universities to explore innovative training model. Tribune of Social Sciences 24, 179–182 (2010) 13. Zhang, X., Wang, H., Lv, Y.: Local colleges and universities innovative training model reform strategy. China University Teaching 33(5), 115–117 (2011)
Fuzzy Comprehensive Evaluation Model in Work of Teacher Performance Evaluation Xiaoling Liu, Haijun Chen, and Feng Yan Handan College, Heibei, 056005, China [email protected], {chenghaijun1968,yan_tian310}@126.com
Abstract. The work of defining the teacher title need to evaluate each teacher’s comprehensive quality in the same post. This evaluation always involved several elements and indexes. Composite fuzzy judge decision-making was used to analyze the evaluation of the expert group, and line up the comprehensive performance of teachers in the same post, so as to define the promotion candidate. Keywords: Fuzzy comprehensive evaluation, Performance, Evaluation.
1
Question Proposed
There was a college evaluating the teachers’ performance, so as to improve the teachers’ enthusiasm of teaching and researching. Defining the teacher’s title and increasing the teacher’s salary accords to his performance. Assuming teachers’ work character were as same as the same post (same title), teachers’ performance were evaluated in accordance with the standard, including of actual performance, teaching level, researching level, political and outstanding achievement. How to line up the performance of 9 teachers in the same post with composite fuzzy judge decisionmaking, according to the experts’ votes, so as to define the promotion candidate?
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evaluation model was one of very effective multi-factor decision-making method to estimate the object influenced by several factors in the round.
3
Model Built and Solved
The math model of fuzzy comprehensive evaluation was composed of 3 factors ( U = factor set, V = judgment set, and R = single factor judgment matrix). It contained 4 steps to solve the model: (1) Building the factor set U = {x1，x 2， ，x N } , be N teachers. (2) Building the judgment set (evaluation set and resolution set)
V = { v1 , v2 ,
v3 , v4 }, be the main difference of the demonstration of the teachers, where v1 :excellent; v2 :good; v3 :ordinary; v4 :poor. (3) Building the single factor judgment matrix. The connection between each factor and the judgment set was expressed by fuzzy connection matrix R = ( rij ) 4× N , where
rij =
cij 4
4
cij i =1
( j = 1,2, N ) ,
c i =1
ij
=m
was
the
expert
number,
and
cij (i = 1,2,3,4; j = 1,2, N ) was the ballot number of the judgment i(vi ) which the teacher j ( x j ) got. (4) Comprehensive Judgment 1) Weight (weight vector) was the coefficient that the importance appointed to a certain number, (if the expert number was less than 30), and it could be calculated by weighted statistic method. Each expert gave a weight vector which he thought was most appropriated according to the judgment standard, and statistic experiment of the weight was made. For example, let the number of the experts who thought the right value v1 =0.15, 0.20, 0.25, …, 0.40 be
wi =
k1 , k 2 , k s , and k1 + k 2 + + k s = m , so the rate
r ki . Computing a1 = wi t i (where t i was weight number, wi was rate, m i =1
and r was serial number), and a j the weight vector
( j = 2,3,4) could be got in a similar way, so
A = (a1 , a 2 , a3 , a 4 ) .
2) Comprehensive Judgment. Consider the effect of various factors, the model was used to calculated, and the comprehensive judgment matrix
M (⋅,+)
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B = A R = (b1 , b2 ,bN ) was got, where b j = a i ⋅ rij , ( j = 1,2, , N ) i =1
is comprehensive judgment of the expert to the teacher
j.
B was the selection result of the project. On the basis of the maximum membership principle, the 9 teachers could be lined up front to back under the points, which was an objective, scientific, and rational method to reflect the comprehensive quality of the 9 teachers. Under such method, the 7 members of the expert group voted to the 9 candidates as Table 1 below: Table 1. The 7 members of the expert group voted to the 9 candidates Factor set Judgment set
x1
x2
x3
x4
x5
x6
x7
x8
x9
v1
3 (c11 )
4 (c12 )
1 (c13 )
3 (c14 )
2 ( c15 )
5 (c16 )
4 (c17 )
2 (c18 )
2 (c 98 )
v2
2 (c 21 ) 1 (c22 )
3 (c 23 )
1 (c24 )
2 (c 25 )
1 (c26 )
0 (c27 )
3 (c 28 ) 1 (c29 )
v3
1 (c31 )
2 (c 32 )
1 (c 33 )
2 (c 34 )
2 (c 35 )
1 (c 36 )
3 (c 37 )
2 (c 38 ) 3 (c 39 )
v4
1 (c 41 ) 0 (c42 )
2 (c 43 )
1 (c44 )
1 (c 45 )
0 (c46 )
0 (c47 )
0 (c 48 ) 1 (c49 )
7
7
7
7
7
7
7
Where cij (i
7
7
= 1,2,3,4; j = 1,2, 9) was the ballot number of the judgment
i (vi ) which the candidate j ( x j ) got. So the single factor judgment matrix R was got:
Fuzzy Comprehensive Evaluation Model in Work of Teacher Performance Evaluation
0.429 0.289 R= 0.143 0.143
0.571 0.143 0.289 0
0.143 0.429 0.143 0.289
0.429 0.143 0.289 0.143
0.289 0.289 0.289 0.143
0.714 0.143 0.143 0
0.571 0 0.429 0
0.289 0.429 0.289 0
361
0.289 0.143 0.429 0.143
According to the weight distribution table,
r
ˊ ˊ
v1 ti
1 2 3 4 5 6
Table 2. Weight distribution table
ti
N i wi
0.1 5 0.2 0 0.2 5 0.2 7 0.3 0 0.3 5
v3
v2
3
0.4285
2
0.2857
1
0.1429
1
0.1429
7
1
0.1 5 0.2 0 0.2 5 0.2 7 0.3 0 0.3 5
N i wi
2
0.2857
2
0.2857
1
0.1429
1
0.1429
1
0.1428
7
1
ti 0.1 5 0.2 0 0.2 5 0.2 7 0.3 0 0.3 5
v4
N i wi
2
0.2857
3
0.4285
1
0.1429
1
0.1429
7
1
ti
N i wi
0.1 5 0.2 0 0.2 5 0.2 7 0.3 0 0.3 5
2
0.2857
2
0.2857
2
0.2857
1
0.1429
7
1
The weighted statistical method was used to calculated the weight according to the r
formula
a j = wi t i (where ti was weight number, wi was rate, and
j = 1,2,3,4
i =1
),
so
the
weight
vector
A = ( a1 , a 2 , a3 , a 4 ) = (0.28, 0.26, 0.25, 0.21) was got. Calculated the model
M (⋅,+)
and the comprehensive judgment matrix was got
B A D R (0.28ˈ 0.26ˈ 0.25ˈ 0.21) 0.429 0.571 0.143 0.289 0.143 0.429 D 0.143 0.289 0.143 0 0.289 0.143
On the basis of the maximum membership principle, the order of interview results of the 9 candidates was lined up from high to low was x6 , x2 , x7 , x8 , x1 , x4 , x5 , x9 , x3
．
Model character and promotion (1) This method combined the qualitative and quantitative analysis together, which could reflect the real situation of the teachers objectively, scientifically, and rationally. (2) The weight confirming was not only in consideration of the experts’ experiences, but also reflected the collective decision-making among the experts through statistic experiment during the data handling. It could reduce the influence of subjective factors to a greater extent, have a higher reliability. (3) This method was simple, easy to operate and promote. (4) Generally, if there were M posts, N ( N > 9) teachers, and m ( m > 7) experts, the software MATALAB could be used to calculate the matrix A R , so that the computation could be reduced, and the calculate process could be simplified.
4
Conclusion
The work of defining the teacher title need to evaluate each teacher’s comprehensive quality in the same post. This evaluation always involved several elements and indexes. Composite fuzzy judge decision-making was used to analyze the evaluation of the expert group, and line up the comprehensive performance of teachers in the same post, so as to define the promotion candidate.
References 1. Xie, J.J., Liu, C.P.: Fuzzy mathematics methods and its application. Mol. Huazhong University of Science and Technology (2000) 2. Liu, X.L.: Composite fuzzy judge decision-making applied in the work of internship. J. Mathematics Communication (2003) 3. Liu, X.L., Yan, F.: Fuzzy Comprehensive Evaluation Model in work of Teacher Recruitment. In: 1st ACIS International Symposiums on CDEE, pp. 346–348 (2010) 4. Liu, X.L.: Fuzzy Decision in work of Confirming City Flower Candidates. Journal of Anhui Agricultural Sciences, 556–577 (2010) 5. Ye, Q.X.: College Mathematical Modeling Contest Guidance Materials, vol. (3). Mol. Hunan Education Publishing House (2002) 6. Ye, Q.X.: College Mathematical Modeling Contest Guidance Materials, vol. (4). Mol. Hunan Education Publishing House (2002) 7. Xie, J.X.: Optimization Model and LINDO/LINGO Software. Mol. Tsinghua University Press (2007) 8. Xu, N.A.: Mathematica Experimental Mathematics. Mol. Publishing House of Electronics Industry (2009) 9. Deng, Z.L., Wang, X., Gao, Y.: Modeling and Estimation. Mol. Science Press (2008)
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10. Mou, S.-b.: The Study on the Algorithm of Curricula Arrangement in College Teaching Management System. Sichuan University of Science and Technology. J. Mol. Med. (4) (2004) 11. Zhang, J.: Implementation of University Course Timetabling on Graph Theory. Journal of Chongqing Teachers College(Natural Science Edition), J. Mol. Med. (1) (2005) 12. Yi, L.-r., Chen, Z.-g.: Development and Implementation of a Web Based Teaching Management System. J. Mol. Med. Systems Engineering (2) (2002) 13. Huang, X., Wu, J., Zhang, S.: Architecture of Distance Learning Management System. Computer Engineering and Applications. J. Mol. Med. (12) (2003) 14. Gu, J.: Sigart Bulletin: Efficient Local Search for Very Large-scale Satisfiability Problems 3(1), 8–12 (1992) 15. Li, Y.-j., Lu, C.-w.: The Use of Ant Colony Genetic Algorithm in Intelligent scheduling course of Colleges and Universities. Modern Electronic Technology. J. Mol. Med. (14) (2010)
Application of Simple Examples in Experiment Teaching about Complex Function and Integral Transform* Yan Yan1, Dianchuan Jin1, Yankun Li2, Huijuan Zhao2, and Xining Li2 1
2
College of Sciences, Hebei United University Qinggong College, Hebei United University, Tangshan, Hebei, China {YanYan,yanjxky}@126.com
Abstract. In Complex Function and Integral Transform teaching, we should follow such a teaching principle that is with application as the goal. According to the background of Complex Function and Integral Transform and combining the students’ specialty, teachers should choose typical cases for the teaching. In order to supply a strong support for the following professional courses, we list and analyse some simple examples in Engineering mathematics about Complex Function and Integral Transform. Keywords: engineering mathematics, experiment teaching, Complex Function and Integral Transform.
1
Introduction
Functions of complex variable and integral transform is not only a required course in many engineering specialty like Electrics, Electronics, communication, automation, exploration, mapping and so on, but also it’s a necessary basic course in many follow professional courses like physical, mechanical, petroleum engineering and other professional courses. The Theory of Functions of a Complex Variable, which is a new branch of mathematics rulling in the nineteenth century, is considered as one of the most harmonious theory in the richest mathematical branch and abstract science. In the early twentieth century, the Theory of Functions of a Complex Variable had been significant progress and opening up further research fields. The Theory and Methods of Complex Function were widely used in mathematics, Natural Science and Engineering. It’s a powerful tool to solve the problem such as Electro magnetics, calorifics, Hydrodynamics and Plane Problem of Theory of Elasticity .The basic content has become a required course of many science majors. Integral Transform, mainly about fourier transform and laplace transform, is a transformation form one function to another function through the integral operation. The Theory and Methods of ComplexFunction were widely applied not only in the branch of mathematics, but also in the fields of Natural Science and Engineering. It had become an indispensable operation tool.
*
The instruction reform project of Hebei United University Q1026-01.
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Mathematical experiment is one kind of scientific research methods between classical deduction and classical experimentation. It’s neither the mathematical application in the usual experiment, nor the experimental transplant in mathematical research. Mathematical experiments, whose production is developed with human thinking, mathematical theory and computers and other modern scientific is a unique research methods. The importance of introducing mathematical experiment teaching in college mathematical teaching course is that: the changes from the traditional learning mode of "teaches + memory + test" to the modern teaching mode of "intuitive + test + error + think + conjecture + proof "and from the one-way communication to multicommunication are helpful to cultivate the students’ creative and practical ability. Combining with visualization of mathematics visual thinking and logical thinking is helpful to cultivate students’ comprehensive ability and quality to solve practical problems by using mathematical knowledge and computer tools. In the automated control, the contents of dealing with signal by analysis of transfer function theory and analysis of frequency domain theory apply the methods of complex function and the transformation of integral transformation. So the functions of complex variable and integral transform plays an important role to learn the professional .Here are some analysis of typical experimental teaching cases in the automatic control.
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The Graphic of Two Rectangular Functions' Convolution Operation
The convolution method is one of most commonly used methods for time domain analysis in linear system. It can solve system to zero state response of any exciting signals and also plays an important role in signal theory. When convolution spreads from the continuous domain to the discrete filter is called correspondingly as convolution sum. It can not only be used to carry out system analysis, but also be called a system realization method. In order to understand convolution operation process intuitively, we can obtain two rectangular function of convolution values by using Fig. methods. As the following chart shows, convolution computation should include the substitution of variable, inversion, translation, multiplication and kirchh off summation; in picture:(a)for substitution of variable (b) for final convolution results; (c) for reverse; (d) for translational multiplication; (e) for continuing translation; (f) for the last values of convolution For example: If you want to obtain the convolution y(t) = x(t) * h(t) of the two
functions x(t) and h(t) , the process of the convolution computation is as the follows: The substitution of variable: t → τ, x(t) → x( τ), h(t) → h( τ) ; the inversion: h(τ) → h(−τ) ; the translation: make a translation of the graphic h(−τ) which has been reversed , then get the graphic h(t − τ) ;
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Multiplication: then, making the multiplication x(τ) and h(t − τ) the overlapping part of the two graphics is the product value, the product value is zero with no overlapping part; Integral summation: the area under the product curve of x(τ) and h(t − τ) (the shadow part) is the convolution value at “t”moment, and continuing shift h(t − τ) until there was no overlapping part of the two graphics h(t − τ) and x(τ) , then you can obtain the convolutional values of all the moment. The graphic whose abscissa is t and the corresponding integral value as vertical coordinate is the graphic of convolution integral y(t) = x(t) * h(t) . As shown in figure (b). By this graphic example, we can draw a conclusion intuitivey: the convolution result of two rectangular function (signal) is a triangle function (signal).
Fig. 1. Convolution of x(t) and h(t)
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Spectrum Analysis of Non-periodic Signal - Fourier Transform
If the signal is not periodic occurrence, but only continue for a while and never repeated, such as the transient, shock wave by explosions and signals by the landing gear landing, then this type of signal is called non-periodic signal. The idea to the analysis of non-periodic signals is: in the time domain, when the periodic turn from T1 → ∞ , the periodic signal changes to nonperiodic signal; in the frequency domain,
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spectrum of periodic signal turning from the limitation T1 → ∞ changes into spectrum of non-periodic signal,and it’s Fourier transform. Example: the spectrum of rectangle pulsation signals, E is pulse amplitude, τ is pulse width. Fourier transform of the spectrum of rectangle pulsation signals is: +∞
+∞
−∞
−∞
F(Ω) f (t)e− jΩt dt = Ee − jΩt dt = (2E / Ω)sin(Ωτ / 2) = Eτ
Because the value of F(Ω) is real numbers, you can only use a curve on one graph to expresse both amplitude and phase spectrum. A single spectrum of rectangular pulse is an abstract function. It’s similar with the envelope curveof the periodic spectrum of rectangle pulsation signals, only the difference factor is 1/ T1 . The rectangle pulsation is limited in time domain and not limited in the frequency domain. The signal energy is concentrated in the spectrum within the first zero of the frequency components, and other high frequency components can be ignored.
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LTI Solving Continuous Systems
If the LTI continuous-time system can be described as a linear constant coefficient N
differential equation:
a y i=0
i
M
(i)
(t ) = b j f ( j ) (t ) , if the input signals and the initial j =0
state of the system are known, we can use the classic time-domain solution of differential equations to find the appropriate system. The function lsim() provided by using MATLAB can simulate the response of the differential equations’ LTI system which was described in the above. The lsim () function can draw the time-domain waveform of the system response specified in any time range in the continuous system. Also it can find the numerical solution of the system response specified in any time range in the continuous system. lsim () function has such call format as following:lsim(b,a,x,t). In the call format, a and b are two row vectors of describing the system (the same meaning with the impulse () function calls.) x and t are two row vectors of showing the input signal. Between them,t is a vector of showing the time range of the input signal;x is t in the signal sampling values on defined time points vector. Such as the following command: t=0:0.01:10; x=sin(t); that defines the sinusoidal input signal sin (t) by range of 0 to 10 seconds (the sampling interval is 0.01 seconds). When the sampling interval is sufficiently small, the discrete-time signal which was defined by vector x and t is the better approximation of continuous signal sin (t).The call format will draw the time-domain simulation waveform of the system's zero-state response by the continuous system
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which was defined by the vectors a and b for the input signal defined by t he vector x and t, and the time range is the same with the input signal.[8]
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Simple Examples in Engineering Mathematics
When teaching the delayed nature of laplace transform, is able to appear, which is how to reflect delayed nature, is what is the result of the delay and is also how to apply in practice. This problem can be explained by the boiler heating system we are familiar with or slow chemical reactions, the convergence of series can be transformed into the problem of stability for the system to discuss and so on. Such examples can be found much and next we illustrate it by a few examples. Example 1: Application of complex function and integral transform in electric circuit analysis course. [9] Suppose series circuit R and L showed as the following Fig. 2, at the time t=0 we connect it to the DC potential E, seeking current i(t).
Fig. 2. RL series circuit
By the Kirchhoff theorem we can know i(t) meet equation: Ri(t) + L
d[i(t)] = E,i(0) = 0 . dt
This is a typical example in circuit-based courses. It is more troublesome that we work out the general solution and the special solution directly. Laplace transform as a mathematical tool make the related operation simplified, and at the same time it is also a powerful tool of linear systems feature in the practical engineering problems. If we use Laplace transform to solve this equation we will get a multiplier effect. Because Laplace transform transforms differential equation that is on time domain t into algebraic equations of complex frequency domain S, which simplifies the operation process and reduces the rate of error. Therefore, we can see from the meaning of the questions: Let I(s) = L[i(t)] , taking laplace transform on both sides of the equation gets: I(s) =
E E 1 1 = [ − ] s(R + sL) R s s + (R / L)
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R − t E (1 − e L ) . R Example 2: Application of complex function and integral transform in power electronic course. [10] We set the selection of unit pulse function δ(t) as an example to explain here.
So i(t) =
Let f (t) be a bounded function that is defined in the domain of real numbers R, and continuous at t = 0, then (if f (t) is a infinitely differentiable function):
∞
−∞
δ(t)f (t)dt = f (0) or
∞
−∞
δ(t − t 0 )f (t)dt = f (t 0 )
.
The nature of the physical meaning is: if product of δ(t) and any continuous function is integrated, the resulte has a clear meaning on the real axis. If you simply say this Nature, it did not have a profound impact on students, and students also do not know what relation exists between the nature and the Follow-up specialized course, but if you add the following example, it will enhance the students’ understanding to the nature. Next we illustrate it by circuit Fig. 3 and 4.
Fig. 3 is three-phase bridge fully controlled rectifier circuit principle Fig.. In a cycle, three groups of bridge arms bridge is conducting in turn, but a prerequisite for conducting thyristor is that we must have trigger pulse, and if the trigger pulse has been working , it will result in the waste of resources. To save resources, according to the order of thyristor conducting at a specific time of a cycle you can add a trigger signal to each tube. For example, select t1 , t 2 , t 3 , t 4 , t 5 , t 6 six times in a cycle of Fig. 4,
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add trigger pulses to the VT1 ~ VT6 six thyristors respectively, and the rest of them time does not need a trigger signal. it saves a lot of resources, makes the physical meaning(namely the Product of δ(t) and any continuous function has a clear meaning on the real axis) of the selection of pulse function well reflected, enhances the students’ understanding of the nature and does the necessary groundwork for the later explanation of this course. Example 3: Deriving Fourier series with engineering examples. Fig. 5 is a square wave signal that commonly used in the practical engineering, but how to accurately express the square wave signal it. As we all know, sine calibrate signal is a common signal with the rules, which can be described with a precise mathematical model, and is the Synthetic basis of many other signal.. But some other calibrate signals are often used in the projects, such as square wave, triangle wave, sawtooth wave and so on, and these signals are very important in practical applications. However, it can not be expressed with precise mathematical model, and need to be synthesized with existing sine wave. Now we set the synthesis of square wave signal as an example to explain the derivation of Fourier series.
Fig. 5. Square wave signal
The function f (t) in the Fig. 5 is an arbitrary square wave function, after a coordinate translation, we can get a square wave signal as Fig. 6, where a 0 / 2 is a amended value, and this square wave can be used to approximate the sine wave. To see such a phenomenon, we can make use of multimedia-assisted teaching to show up the results simulated by Matlab.
Fig. 6. The square wave signal through the coordinates
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Conclusion
In the teaching principle "Application for the purpose, necessary and sufficient for the degree ", optimizat the teaching content of " functions of complex variable and integral transform", try to combine the professional of students, make use of the actual Background and application produced by complex variable function and integral
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transform, choose a test case with professional backgrounds for the teaching. Focus on achieving students’ seamless connection of "learn" and "use", improve the teaching effect, make a strong support for the following professional courses, enable students to mastery, learning process.
References 1. Deng, y., Lv, Y.: Educational Research and Reform on the Course of Function of Complex Variable and Integral Transform. Journal of Nantong Institute of Technology: Social Science (4), 36–38 (2004) 2. Zhou, C., Jiang, S.: The New Study on Contents of Complex Variable Function and Its Teaching Methods. Journal of Changchun Teachers College (11), 134–135 (2005) 3. Xie, j., Qiu, J.: Research and Practice Oil Teaching Reform of Functions of Comples Function and Integral Transformations. Journal of Hefei Teachers College 27(3), 26–28 (2009) 4. Xue, D., Chen, Y.: Advanced Applied Mathematical Problem Solutions with MATLAB, 2nd edn. Tsinghua University Press (2008) 5. Chen, X., Shi, Q.: Exploration and Practice of Teaching Innovation in Higher Mathematics. Higher Education in Chemical Engineering (2), 22–24 (2008) 6. Zhang, N., Gao, F.: A New Study of Complex Variables and Integral Transform Teaching Reform. Heilongjiang Education (Higher Educational Research and Evaluation) (6) (2010) 7. Xiong, C., Chen, C., Duan, H.: Engineering complex function of the migration of teaching. College Mathematics (04) (2010) 8. Zhang, W.: Application of Simple Examples in Engineering Mathematics. Modern Electronics Technique (12) (2010) 9. Yan, Y., Jin, D., Jiang, J., Li, Y.: Analysing Mathematics Experiment Teaching in Functions of Complex Variable and Integral Transform. In: Proceedings of International Conference of China Communication and Technology, ICCCT 2010 (2010) 10. Lu, Y.: Primary Exploration on the Teaching Reform of Complex Function and Integral Transform. Journal of Jiangsu Teachers University of Technology (02) (2011)
Competency Based Human Resource Management Reform in Undergraduate Teaching Li Wenhui Xi'an University of Finance and Economics, Xi'an, Shaanxi, P.R. China, 710100 [email protected]
Abstract. Since the selection of training mode is decided by the market demand, undergraduate education should be closely identified with the market demand for talent education content and methods. This paper has studied on the early competencies of human resources management factors on the basis of structural equation modeling to analyze the factors that influence the level of competence so as to make clear the market demand of the undergraduate training of human resources management, based on which it presents the idea of changing the traditional knowledge-giving teaching mode into a competencytraining mode, and case learning, situational training, scheme design of human resource management are discussed as part of the undergraduate teaching improvement research. Keywords: competency, structural equation management, undergraduate education reform.
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needs out of touch, incompetent HR management, is bound to human resources and goals run counter to teaching undergraduate students into the teaching of basic tasks to complete disregard of the actual market demand for the error. Talents from the market demand, undergraduate education should be combined with the market for talent just needs to determine the content and methods of education. This paper is to obtain through market research in the pre-qualified KSAO HR and quantitative research conducted on the basis of competence to explore the factors associated with the degree of human resource management to Fund: University teaching and research project in Xi'an University of Finance and Economics, Human Resource Management System of innovative teaching practice and Operation Mode(10xcj13) determine market demand for undergraduate training, then human resources management degree teaching make specific recommendations for improvement.
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A Research Method
First, the basis of a characteristic early indicator system design competence of human resources management research questionnaire; followed by questionnaires and collect research data, 70 in Xi'an randomly selected private enterprises and state-owned enterprise human resource practitioners to conduct research. Finally, it constructs structural equation model. This article has been constructed according to preliminary studies of human resource management competencies of the SEM model path diagram of factors, in-depth analysis of various factors on the extent of their competence impact. On this basis, human resources management improvement of undergraduate teaching.
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Previous Research Conclusions
First, statistical data SPSS16.0 descriptive statistical analysis is used to get a preliminary validity of the variable, having deleted the inefficient variable; then the reliability of the questionnaire is analyzed deleting variables that affect the overall reliability; finally, the constitutive equation model is built and the SEM model of human resources management factors is designed to determine the path coefficients (see Table 1). k13
.14
k21
k1
B1
k2
B2
k3
B3
k4
B4
.65
k5
B5
.53
k12
D4
.47
知识及应用能力
.68 .61
k10
D2
D1
D3
.63 .50
k11
.84
.72 .53
人格特点
k23 k24
.25
k22 k6
C1
k7
C2
k8
C3
k9
C4
.51
学习与适应能力
.56
胜任工作能力
.71
.85
团队工作能力
E2
k15
E1
k14
F3
k18
F2
k17
F1
k16
.74
k25 .22
.26
.64 .60
.49
.40
G1
H1
k19
k20
情绪调控能力
.42
.49 .71
Fig. 1. SEM model of human resources management factors of path coefficients
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Fig 1 shows the correlation between the potential variables and observing variables, which clearly shows that the measuring factor load and the corresponding potential variables and using ability, learning and using ability, personality, team work ability, mood control is generally bigger than 0.5 with o.42 the minimum, which shows the validity of the 20 measuring factors. Table 1. Human resource management competencies Factors SEM model path coefficients Factors (correlation coefficient)
The corresponding variable factors(load factor) Organization, coordination (0.63)
Knowledge and application ability (γ1=0.84)
Team work (γ2=0.85)
Learning and adaptabilit y (γ3=0.71)
Problem-solving skills (0.68) Knowledge of Human Resource Management(0.61) Human resources management expertise(0.65) General management knowledge(0.53) ability to Analysis and judge (0.74) Teamwork(0.49) Adaptation(0.51) Resilience(0.56) Learning ability(0.64) Creative Thinking(0.60)
Factors (correlation coefficient) Work experien ce (γ4=0.40) Interpersonal skills(γ5=0.26)
The corresponding variable factors (load factor) Experience in human resources management Interpersonal communication skills Initiative(0.53)
Self-control(0.71) Ability to withstand pressure(0.49) Affinity(0.42)
By Table 1, knowledge and application ability (γ1=0.84), team work (γ2=0.85), learning and adaptive capacity (γ3=0.71), work experience (γ4=0.40), interpersonal skills (γ5=0.26), Personality characteristics (γ6=0.25), emotional regulation capacity (γ7=0.22) seven categories of indicators of human resources competencies were shown a positive relationship between the causal effects. Where knowledge and application ability, learning and adaptability, team work ability, work experience, these four categories of indicators (ã>0.5) for the human resource competence showed a significant positive correlation between interpersonal skills, personality, emotional regulation and control (ã<0.5) for the competence of human resources do not show a significant positive correlation.
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First, team work (γ2=0.85) of the most significant, while the ability to analyze and judge the ability of the team than the ability of the team to work more significant. Practice, human resource managers in a constantly changing environment of timely and correctly, to judge the impact of staff motivation and job performance factors is to mobilize the enthusiasm, the potential developers a prerequisite, but also should have HR basic skills. Knowledge and application ability (γ1=0.84) is also a very significant impact factors, and problem solving, human resource management expertise, organization and coordination, human resource management expertise, knowledge and application ability of both a significant impact. Practical work using the appropriate professional knowledge and skills to solve a variety of people, problems between people and things are all important work of human resource management content. Learning and adaptive capacity (γ3=0.71) of the more significant impact, and learning ability, creative thinking ability in learning to adapt to relatively more significant. Complex human and organizational environment requires HR needs quickly and continuously updated according to their own environmental knowledge and skills, resulting in a complex environment with a competitive edge for the organization's human resources. While other indicators as well as work experience, interpersonal- skills, personality and emotion regulation ability of the corresponding indicators for the impact of HR competencies relatively not significant. Above analysis, HR competencies of the most important factors can be summarized as analysis of judgments and problem-solving, teamwork, human resource management expertise and knowledge, creative learning.
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Competency-Based Human Resources Management Reform of Undergraduate Teaching
Through the above results of quantitative analysis to determine human resource management can be the improvement of undergraduate teaching students to analyze problem-solving skills to develop teamwork and expertise, to impart knowledge, to develop students as a key innovation to meet the market for human resources undergraduate students employment needs. In response to these teaching points, should the traditional teaching mode, which impart professional knowledge-based teaching reform aim to foster the practice of competency-based teaching, supplemented by theoretical knowledge imparting teaching. Combined with my long teaching experience in human resources management, summed up the case method, scenario simulation, training of human resources management programs such as practice teaching methods designed to cultivate human resources professional competence of students tested. 4.1
The Case Teaching Method
Harvard case method introduced by the United States to train students with good decision-making capacity, to help them learn in a changing environment in how to deal with various problems. Case law used in the teaching of human resources management expertise to train students to use and to identify problems based on organizational
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environment, analyzing and solving problems, while students teamwork and decisionmaking, thus enhancing their human resource management expertise. Case method can be applied in two forms in human resources management teaching: First, classroom teachers, teaching with case expertise. Second, after-school students to integrate professional knowledge for case discussion. Case teaching on human resource management skills of teachers and the ability to analyze and solve problems raised higher requirements. Only teachers have quickly discovered the problem, problem solving skills and a wealth of human resources management expertise to be able to navigate in case teaching, case step by step guide students to analyze information, identify problems choosing the right perspective and solve problems. The first way is by teachers in the process of imparting knowledge of the interspersed case associated with the theory of teaching and learning activities undertaken (including interaction) to increase the professional knowledge of learning fun, and promote student understanding and acceptance of knowledge. Transformation of knowledge into professional skills to promote and train students to use knowledge to solve specific problems. The second method case comes from two aspects, one teacher teaching content according to a written case and issues, and second, given the theme selected by students in teams and problem cases. After-school way for group discussions, classroom group reporting the results of group discussion and listen to the students of different opinions. Finally, teachers were guided analysis of the case until consensus. Panel discussion of case selection and to develop students ability to control information on the case to determine the issues and the ability to analyze and solve problems, including the importance of information quickly to judge, exclude irrelevant information, the inference drawn according to known information unknown information, further found that the case related issues, and apply professional knowledge and skills in specific programs to solve problems; group together to complete case analysis by students to organize and coordinate training capacity to share the task of the team in the form of students and also the team spirit, mind of the storm continues to inspire all type of creative thinking, thinking based on different perspectives students a comprehensive analysis of system problems. Case teaching method from the above analysis we can see a lively, strong participation, will develop the ability to solve practical problems into knowledge transfer, is the training of human resources management competencies is very important teaching method. Ping-BA students who applied talent to become the target, so the teaching of human resource management professional should be large, high frequency application of case method, as far as imparting knowledge points in each are able to combine teaching, can be specific to the use of Simple example to explain each knowledge point, especially for the needs of the students to grasp key concepts and case teaching skills must be designed accordingly. 4.2
Scenario Simulation
Scenario simulation is the most characteristic of modern HR work, one of the most complex, the most effective techniques, this method is participatory, easy for students
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to generate interest. Scenario simulation technology used in the teaching of human resources, is placed in the simulation students play different roles in the scenario, ask students to deal with situations. they may encounter various problems, through the active participation of students in a simulated training to enable students to learn visually to acquire the relevant human resource management and operational skills. "Talent Test" teaching through simulation can help students master the role of various test methods, concrete work construction jobs in the competence of each model, the teacher's performance can be further evaluated for their quality and ability to develop characteristics of students who analytical ability; "Job analysis" in teaching, such as allowing students to simulate the work of information for presentation interview scenarios, teachers and students to discuss the interviews and assessment methods, through their participation will encourage students to master a variety of work of technology; "Performance management" teaching arrangements for students to play different roles to show performance management scenarios, scenario by which to stimulate students to analyze the existing performance management issues and propose solutions to problems, improve practice and theory to students analyze and solve problems. The same applies to human resources scenario simulation teaching other professional activities. 4.3
Human Resource Management Training Program Design
Design of human resource management human resource management capacity is a major component of professional skills. Scientific and rational design is to carry out human resources management, including job analysis, human resource planning, recruitment, training and development, performance management, compensation management, career planning, the premise of each module. HR professionals also have the basic skills. Basic knowledge of traditional teaching to learning and capacity-building program designed split away from undergraduate teaching human resources management objectives, also out of the market demand for talent. "Job analysis" of teaching can require students to analyze specific business implementation plan preparation, job-specific preparation instructions; "Human resource planning" teaching students to arrange existing human-specific business conditions and the manpower needs of organizational development plan forecasting and supply forecasting, preparation of human resources planning book; "Training and development " of teaching students to organize job training needs of specific research and analysis, design training programs; "Performance management " of the teaching needs of students for specific positions for a large number of performance appraisal index system. on this basic, with specific companies to complete performance program design; other teaching process, students should also be organized to conduct a pay program design, program design, career development activities. Enterprises through a combination of practical human resource management programs in different modules of training designed to promote professional theoretical knowledge into professional skills, which students apply knowledge to solve organizational problems in human resource management capacity, will also fit the students to provide basic HR professional and technical skills.
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In addition, human resource management information system simulation training is to train students to master the use of human resources management information system skills, effective method, especially in a large number of personnel evaluation in the use of information systems technology needs assessment.
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Conclusion
The structural equation HR competency research data processing results applied to guide human resource management teaching activities, for the correct choice of teaching content and methods provide a quantitative basis for scientific theory. Found through research, practice-based teaching, supplemented by theoretical teaching is to develop HR competencies of effective teaching model. Features for human resource management, training focus, and I made a case method of teaching experience, scenario simulation and training program design specific and effective practices such as teaching, and described their specific applications. Practical application of the above will help to set up teaching theory and practice, classroom and enterprise, learning and practicing a bridge between the university on the HR in order to achieve the objectives of undergraduate training, and personnel training so that targeted and effective service to the needs of society to produce a good social effect.
References 1. David-McClelland, C.: Testing for Competency Rather Than Intelligence. American Psychologist (28), 1–14 (1973) 2. Li, W.: Human resources management competencies components of empirical research. Statistics and Information Forums (2010) 3. Li, H., Niu, X.: Competence-based teaching methods of human resource management. Hubei University of Economics (Social Science Edition) (2006) 4. Spencer, L.M., McClelland, D.C., Spencer, S.: Competency assessment methods: History and state of the art. Hay-McBer Reserch Press (1994) 5. Anderson, J.C., Gerbing, D.W.: Structural equation modeling in practice: A review and recommended two-step approach. Psychological Bulletin 103, 411–423 (1988) 6. Li, W.: The ‘1+1’ Talent Management Model: The Key to Solve SME’s Talent Problem in Remote Areas. Journal of Xi’an University of Finance and Economics (2011) 7. Gu, Q., Zhu, M.: Competency Study of Human Resource Management. Human Resource Development of China 9, 4–8 (2001) 8. Zhang, W., Shao, M.: Training of Human Resource Management from the Perspective of Competency. Industrial & Science Tribune (7), 1 (2008) 9. Liu, F.: Enhancing the Necessity and Ways of Practice Training of Human Resource Management. Higher Education Forum 3, 135–137 (2006) 10. Liu, Y., Linsuyang.: Research of the Practice Training of Human Resource Management of Local Colleges and Universities. China University Teaching (8) (2007)
The Application of Genetic-Neural Network on Wind Power Prediction Rui-Lin Xu1, Xin Xu1, Bo Zhu2, and Min-you Chen2 1 2
Chongqing Electric Power Research Institute
College of Electrical Engineering, Chongqing University, Chongqing 400044, China
Abstract. As a renewable energy source, wind power is considered to be a significant alternate source of energy in the times of energy crisis. As wind power penetration increases, power forecasting is crucially important for integrating wind power into a conventional power grid. A short-term wind farm power output prediction model is presented using a neural network optimized by a genetic algorithm (GA). Using wind data collected from a wind farm in Inner Mongolia of China, a power forecasting map is illustrated, and a comparative study between a Back-Propagation (BP) neural network model and a GA-BP neural network model is undertaken. Keywords: Renewable energy, wind farm, prediction, Artificial Neural Network, Genetic Algorithm.
1
Introduction
In the wind farm, the power generated by a wind turbine generator varies randomly with time due to the variability of wind speed. Uncertainty of the wind power and wind power penetration increasing will affect system stability and run the risk of blackouts. Therefore, a new operational strategy based on precise wind power forecasts is necessary, and it is important for the power industry to have the capability to estimate power variations. The fluctuation of wind speed results in rapid changes in the electric power generated by electric wind turbines; the forecasting model will inevitably be non-linear. Many different approaches have been used to forecast wind farm power, such as an Auto Regressive Moving Average Model (ARMA) [1], a Kalman Filter Model [2], and Artificial Neural Networks [3, 4, 5]. Comparing the ANN approach with other methods, it is found that ANN is more suitable than others because the wind prediction is a complex nonlinear process and ANN has better ability to simulate the complex nonlinear system than the linear methods above. An ANN model has the advantages of parallel processing capability, non-linear mapping, fault-tolerance and self-adaptive learning [6]. It performs well on pattern recognition and prediction problems [7]. The Back Propagation Neural Network (BPNN) is the most widely used neural network. A BP learning algorithm is based on gradient descent which is prone to getting stuck in local minima. In order to avoid this
situation and enhance predict precision, a Genetic Algorithm (GA) is used to optimize the initial parameters of the network, such as weights and bias of the BPNN. Genetic Algorithms are probabilistic search algorithms based on the principles of biological natural selection and the genetic evolution mechanism [8]. They have a global search capability in complicated, nonlinear problems. This paper presents a wind power prediction model based on GA-BP neural network, which is shown to outperform the conventional BPNN model.
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Wind Farm Modelling
In this section, major factors affecting wind farm power are analyzed and a prediction model of wind farm electric power output is presented. 2.1
Major Factors Effecting Wind Farm Power
Wind farm output power comes from wind power captured by wind turbines. So the wind power can be calculated using P=
dE 1 dm 2 1 1 = ⋅ v = ( ρ ⋅ Av) ⋅ v 2 = ⋅ ρ Av 3 (Watts) dt 2 dt 2 2
(1)
where m is the air mass ( kg ) , v is the air speed in the upstream wind direction at the entrance of rotor blades ( m / sec . ), ρ is air density ( kg / m ), A is area swept by rotor blades ( m ). Following the same principle, the actual power extracted from wind turbine blades 3
2
can be obtained using (1), where the air mass flow rate through wind turbine blades
dm dt
has changed; so the mechanical power extracted from wind turbine blades can be obtained using (1): 1 dm 2 1 dm 2 1 dm 2 2 1 v + v0 2 2 P0 = . v − . v0 = . (v − v0 ) = .[ ρ . A. ](v − v0 ) 2 dt 2 dt 2 dt 2 2 v v (1 + 0 )[1 − ( 0 )2 ] 1 1 v v = .ρ . A.v 3 . = .ρ. A.v 3 .C p (Watts ) 2 2 2
(2)
where v is the air speed in the downstream wind direction at the exit of the rotor blades ( m / sec . ) and C is the rotor efficiency, and it is shown by equation (3) 0
p
Cp =
(1 +
v0 v )[1 − ( 0 ) 2 ] P v v = rotor 2 Pwind
(3)
where v0 = x , so its maximum value can be calculated by differentiating (3) with v
respect to x, and when x =
1 , we can get the maximum value of the mechanical 3
power extracted from wind turbine blades :
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Pwind max =
1 1 ρ Av3 .C p max = ρ Av3 .0.593 2 2
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(4)
We know that C is a function of wind speed, turbine speed and turbine blade parameters, such as pitch angle, angle of attack. Therefore, in variable speed wind turbines, rotor speed is varied to hold C at its maximum value. Therefore, output power of a wind turbine generator, P is proportional to P . For a fixed wind turbine, the area swept by the rotor blades is constant, so P is proportional to the air density ρ , and the air speed in the upstream wind direction at the entrance of rotor blades v , and ρ is determined mainly by air temperature. Therefore, the major factors affecting wind farm electric output are simplified to air speed and air temperature. p
p
wind max
2.2
Prediction Model of Output Power of Single Wind Turbine Generator
In this model, a BP neural network is used to forecast the wind power generated by a wind turbine generator. But the initial weights and bias are obtained using a GA, and then a gradient descent search is used to find a global optimal solution. As mentioned in Section A, the major factors affecting wind turbine output are air speed and air temperature, so they can be used as model inputs, and can be obtained from a Supervisory Control and Data Acquisition (SCADA) system installed at a wind farm [9]. Because the forecast is used by the operational department of power system, and in order to improve the accuracy of prediction, the historical power output collected by the Energy Management System (EMS) can be used as input. The wind power can be used as single output. In order to get good prediction precision, the inputs can be expanded into time series of historical data of air speed, air temperature and wind power. The number of hidden layer nodes can be confirmed by performance of network training. In the BP algorithm, the gradient descent method is susceptible to getting stuck in a local minimum. As GAs have a strong global search ability, we use a Genetic Algorithm to search for the global optimum. In the region of the global optimum, the gradient descent method is used to refine the search for the global optimum on account of its faster search rate and strong local search capability. The network consists of n input nodes, h hidden layer nodes, and m output nodes connected in a feedforward fashion via weights Wij . And neurons in the hidden and output layers have an S-shaped transfer function known as the “sigmoid activation function”, f ( z ) = 1 / 1 + e − z . Thus, once the structure of the neural network is confirmed, the learning process is divided into two steps. Firstly, the parameters of network are initialized and coded. In this step, the purpose of optimizing is to minimize the value of sum of squared errors (SSE) between the actual output and the target output. The reciprocal of SSE is chosen to be the fitness function. Individuals with better fitness will tend to be selected by means of the selection operator. After selection, crossover and mutation are carried out. Repeating
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the procedures of calculating fitness, selection, crossover and mutation until a termination condition is satisfied, the initial parameters of network are optimized.
Fig. 1. GA-BP flowchart
In the second step, fine tuning of the solution is carried out. In the vicinity of the global optimum obtained from the first step, the gradient descent method is used to search the optimal weights and bias. This step is similar to training the standard BP network. The outputs produced by the ANN in response to inputs are repeatedly compared with the correct answers. Each time the W ij values are adjusted in the direction of the correct answers by backpropagating the error at the output layer through the ANN according to a gradient descent algorithm. When the termination condition is satisfied, it is time to forecast the wind power using this network. The GA-BP flowchart is shown in Fig. 1. 2.3
Prediction Model of Output Power of Wind Farm
Wind farms consist of several wind turbine generators (WTGs) and the power output of a wind farm is the total power of each turbine. In order to predict the electric power of wind farm, we can divide a wind farm into several wind turbine generation units, and the power of each unit is predicted first and then the outputs of all of the units are aggregated to calculate the wind farm power [10].
3
Case Study
In this section, we give an example of the wind power prediction by means of GA-BP neural network with real measured data obtained from a wind farm in Inner Mongolia
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of China. The measured data from 25 days are used as original data to train and validate the network. The data arising from the first 20 days are used to train the network and the data arising from the last 5 days are used to validate the trained network. We use the data during the latest 3 prediction periods as input to the network to predict wind power over the next period. The period can be regulated in half an hour, an hour, two hours, etc. After running the program several times, we confirm the most suitable number of hidden layer nodes is 35. In this example, a BP neural network and a GA-BP neural network are each used to predict the wind output power and we can compare the performance and error of each model. The model is designed using MATLAB. The GA-BP model is designed as follows: Firstly, a BP neural network is built and we can confirm the structure of this network: the input layer nodes number R is 9, the hidden layer nodes number S1 is 35 and the output layer nodes number S 2 is 1. The weights and bias are generated randomly. In the second step, Genetic Algorithm is used to optimizing the weights and bias. The initialized weights and bias are coded by the decimal code, and the codes are put into the chromosome which represents the character of the individual in the population, the chromosome length S is given by the following function: S = R * S1 + S1* S 2 + S1 + S 2
(5)
So the length S is 386. And in order to get the minimum value of the sum-squared error between actual output and target output, during the optimizing, the fitness function is adopted by the reciprocal of the sum-squared error, which is shown as function (6): 1
F it fu n =
(6)
n
1 n
( O ( k ) − T ( k ))
k =1
where n is the number of output layer nodes, O(k) is the actual output of the k′th node in output layer, T(k) is the target output of the k′th node of the output layer, and in this program, n is 1. After the fitness function is confirmed, other parameters of Genetic Algorithm will be given. In this program, the population size is 30, crossover probability is 0.65, mutation probability is 0.08 and the number of generations is 50. So the selection, crossover and mutation are carried out in the 30 individuals. After the procedure, the fitness value is calculated by the fitness function again, and selection, crossover and mutation are repeated until generating 50’th generation, the optimal weights and bias are confirmed. If the prediction period is 0.5 hour, the optimizing process is explained by the Table1. Table 1. SSE and Fitness value in different generations Generation
...
49
SSE
439.9472 424.9894
1
2
...
194.8558 194.8178 194.8178
...
194.8178
Fitness value
0.002273 0.002353
...
0.005132 0.005133 0.005133
...
0.005133
...
40
41
42
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From the table above, we find the sum-squared error getting smaller and the fitness value of the best individual getting larger as the generation increasing. From 41’th generation to 50’th generation, SSE and fitness value has not been changed. Finally, the optimal weights and bias are put into the neural network, and trained by the traditional BP Algorithm until meeting the end condition. After this step, the neural network can be validated by the data in the final 5 days. Figure 2 shows the result of the wind power prediction whose period is 1 hour with two types of neural network. In the left graph, we find there are some very sharp spikes in forecasts. But in the right graph, the predicted and measured values are relatively consistent. Analyzing the reasons we find GAs have a strong global search ability, and in GA-BP model the result of searching is better than that in BP model. Comparing the two graphs, we find the performance of the GA-BP model is superior to that of the BP model.
Fig. 2. Real measured and predicted wind power (prediction period=1 hour)
Fig. 3. Real measured and predicted wind power (prediction period=0.5 hour)
Figure 3 shows the result of the wind power prediction whose period is 0.5 hour with the two types of neural network. Similarly, the GA-BP model is superior to that of the BP model. Comparing Figs. 2 and 3, we find the result in Fig. 3 is superior to that in Fig. 2. In Fig.3, the predicted and measured values in GA-BP model are almost entirely consistent because the prediction period is shorter than that in Fig. 2, the correlation of previous weather and current weather is smaller, it will improve the prediction accuracy. Therefore, the prediction accuracy and the prediction period are closely related.
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Table 2. Comparison of prediction errors of wind power over multiple runs BP model Running times of RMS errors(kW) Relative errors(%) models 0.5h 1h 2h 0.5h 1h 2h 1 93.61 168.01 258.03 10.95 19.76 30.34 2 94.38 152.53 269.21 11.03 17.95 31.67 3 97.14 156.95 295.55 11.43 18.44 34.77 4 95.19 163.29 294.35 11.17 19.22 34.63 5 96.31 162.15 269.19 11.33 19.06 31.67
The Table 2 shows the root-mean-square error (RMSE) and relative error of each model for different prediction periods over multiple runs. From the errors in Table 2, we observe that the performance of the simplified model has been improved by using the GA and the GA-BP model can supply the minimum error. When the prediction period is 0.5 hour, the model attains the highest prediction precision. This period can meet the needs of operational department in power system.
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Conclusion
Based on the historical data of a wind farm, the application of a BP and a GA-BP neural network for wind power prediction are compared. It has been found that wind power can be successfully predicted using GA-BP neural network. The prediction by direct use of the BP neural network has the larger error. The performance of the GA-BP neural network forecast algorithm is superior due to the improved optimization of the weights and bias of the network. So the model performs well in forecasting wind power output. With more parameters, the model can forecast power output better. Further studies will be carried out to improve this simplified model, such as considering effects of other factors which are wind direction, humidity, etc.
References 1. Torres, J.L., Garcia, A., De Blas, M., De Francisco, A.: Forecast of hourly average wind speed with ARMA models in Navarre (Spain). Solar Energy 79, 65–77 (2005) 2. Louka, P., Galanis, G.: Improvements in wind speed forecasts for wind power prediction purposes using Kalman filtering. Journal of Wind Engineering and Industrial Aerodynamics 96, 2348–2362 (2008) 3. Mishra, A.K., Ramesh, L.: Application of neural networks in wind power (generation) prediction. In: 1st International Conference on Sustainable Power Generation and Supply (2009) 4. Lin, X., Li, B., Xu, j.: A novel power predicting model of wind farm based on double ANNs. In: 2010 Asia-Pacific Power and Energy Engineering Conference (2010) 5. Schalkoff, R.J.: Artificial Neural Networks. McGraw-Hill Press (1997)
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6. Carolin Mabel, M., Fernandez, E.: Analysis of wind power generation and prediction using ANN: A case study. Renewable Energy 33, 986–992 (2008) 7. Bishop, C.M.: Neural Networks for Pattern Recognition. Oxford University Press (1995) 8. Lankhorst, M.M.: Genetic algorithms in data analysis. Brooks/Cole Publishing Company (2006) 9. Rohrig, K., Lange, B.: Application of wind power prediction tools for power system operations. In: 2006 IEEE Power Engineering Society General Meeting, PES (2006) 10. Kusiak, A., Zheng, H., Song, Z.: Wind farm power prediction: a data-mining approach. Wind Energy 12, 275–293 (2009)
Design a Mobile Tetris Game Based on J2ME Platform Jian-Ping Wang1, Jun Chen1, and Xiao-Min Li2 1
School of Information Engineer, Henan Institute of Science and Technology, Henan, Xinxiang, 453003, China 2 School of Technique and Electricity, Henan Institute of Science and Technology, Henan, Xinxiang, 453003, China
Abstract. At present, the development of the mobile game based on J2ME is very popular. How to transplant the traditional PC games into the mobile platform, and how to design the stable and reliable game based on the mature game algorithm are the key parts of the development of the mobile game. This paper focuses on the development and design process of the mobile game named Tetris, and the detailed description of the key technologies is also provided. Keywords: Mobile Game, J2ME, Tetris, Game Algorithm.
1
Introduction
Tetris is a popular classic game in the whole world. It was invented by the Russians. The basic rules of Tetris are by moving, rotating and displaying the various blocks automatically outputted by the game, arranging the blocks in one or more than one complete lines, and then eliminating them to get scores. As this game is easy to learn, suitable for people of all ages, so it is very well-known and popular in the world. As the universal popularization of mobile networks, the mobile phone-based games become popular. Among them, the J2ME based games as representative occupy a large market share. J2ME was produced by Sun Company, aiming at embedded consumer electronics. J2ME, J2SE and J2EE make up the three important branches of Java technology. J2ME is actually a collection of specifications. JSR (Java Specification Request) was established and issued by JCP organization. Each manufacture will follow the specifications to produce their products. The products must pass TCK test to ensure compatibility. Sun Company defines J2ME as “a highly optimized Java running environment aims at general consumer products”, including Pager, mobile phones, video phones, digital STB and car navigation system GPS. After it was issued at Javaone Developer Conference in June 1999, J2ME entered into the ranks of small equipment. Because of Java’s cross-platform features, Java program, which was developed to follow the J2ME specification, can run on a variety of small devices.
The main function of the project is to achieve a Tetris game, including the achievements of all the functions of the game. The rule of the game is: during the game, the player can control the location and the shape of the continuously falling Tetris, allowing them to choose the appropriate locations and shapes, so as to fill the vacancies, eliminate the Tetris and get scores. The more lines the player eliminates, the higher score he gets. And the degree of difficulty will be accelerated with the falling speed increases. The game is suitable for the mobile phones which can support JAVA MIDP2.0, and the screen size of 128*128. All the functions of the game: rules, achievement, and records of the game, music player function, should be achieved. 2.1
Game Technical Indicators
The so-called playability means the playable level of the game and the degree of the game can attract players. The playability of a game is the core of the game quality, and the reflection of the game value. Whether a game is playable, and the degree of playability will determine the success of a game. The quality of the game is a parameter that is used to assess the game comprehensively, such as: the running speed of the game, the storage space the game occupies, whether there are mistakes or not in the game, and bug, which is the indirect reflection of the playability of the game, usually assessed after a period of time’s testing. 2.2
Development Constraints
The design of the mobile game should be reasonable. The reasonable realization of the game program code should ensure the correct implementation of the project without any errors or exceptions. The implementation should be stable without errors, and the speed of implementation should be fast enough. The storage space of the mobile game should be less than 200KB, it should be small enough to fit the characteristics of mobile phones. The function of the project should be fully achieved, and the project can show the design function at earlier stage. 2.3
Design of the Main Module
(1) UI interface and initialization module Its main function is to realize the paintings related to UI interface during the game, including, the game menu interface UI, game end screen UI, game help screen UI, the initialization of some UI related data. (2) Running and processing module The main function of this module is to achieve some processing during the game, including: data operation during the game, data processing, organization and control of the elements during the game. It is the main operation module of the game.
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(3) Button control module The main function of this module is to achieve the control of the game by accepting the player’s pressing button. This is an external interface module, it connects the player and the game. It is the main module for the player to control the game. (4) Command button function module The main function of this module is to achieve the player’s control over main menu by accepting the player’s pressing order button and issuing command to main game logic module. It belongs to interface module between player’s command and main game logic module. (5) Main logic achieving module The main function of this module is to achieve the control of entire game running process and the game’s main process, mainly including the conversions between various game interfaces and some processing of various procedures of the game. 2.4
Division of the Key Classes
(1) Model class: this one inherits the MID let class, and used to transfer the game to the phone and execute the game. (2) Diamond Map class: this one is user-defined classes, used to check the diamonds. (3) Diamond Canvas class: this class is user-defined, it is used to achieve the game show and game control. It belongs to the core class, and inherits from Canvas class. (4) Diamond Maps: this class is user-defined, used to generate the game required diamonds. (5) Play music: this class is user-defined, mainly used to play and control background music during the game.
3
Design of the Key Modules
The key modules of this mobile game are the designs of button control and diamond change. 3.1
Button Control
Button control means to achieve the control of the game by receiving the player’s operation on phone keyboard. It includes the module of by receiving the player’s operations to control the game. Its main function is to achieve the specific operations when player is playing the game. Another main button control is the game menu and command button processing module. The main function of this module is to achieve the functions of all the menus and command buttons. The main flow of button control is: players presses the buttons-->recognition of the buttons and issuing the command-->achieving the response of the control.
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Button control related codes: if (gameState == this.GAME_STARTED_DEMO) { information of game DEMO} else if (gameState == HELP_MESSAGE) { paintpage(lable, page, g);} else if (gameState == GAME_INIT) { //game’s first start//draw the game logic map(container part) i.e. the boundaries of game areas} map.init(); map.paint(g); map.paintScore(g); this.maxCounter = 10; map.paintmaxCounter(g);// according to the type of diamonds(random numbers), initialize the falling object logically block.init();//draw the present and next falling object block.drawBlock(g); block.drawNextBlock(g); // set game speed and next game state this.counter = 0; gameState = GAME_RUN;} else if (gameState == GAME_RUN) { Redraw the game areas after a pause if (resumeispaint) { this.gamerepaint(g); resumeispaint = false;} counter++; if (this.counter >= this.maxCounter) { / check decrease every 8 pauses, as the maxCounter becomes smaller, the falling speed will be faster if (block.checkDown(false)) {// check falling (automatically) block.down();//remove the old graphics, draw a new falling object, and save the current coordinate value as the old one block.paint(g);} else {//cannot fall any longer, delete lines // draw graphics, set the coordinates int y = block.getYBrick();//no more decline, but re-draw the falling object directly block.paint(g);// draw the logic map of the data according to the current position of the falling object
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// Connect the falling object with MAP, and put it in MAP block.fixBlock();//check from y to next 4 lines to see whether there is elimination if (map.check(g,y)) {// Check whether it can meet the standard, and can speed up if (map.score >= (10 - maxCounter + 1) * 1000) { if (maxCounter > 1) {this.maxCounter--; map.paintmaxCounter(g);}}// redraw the game areas map.repaintMap(g);} // re-initialize the falling object logically according to generated type of bricks block.init(); // check whether the game is over if (block.getYBrick() < 0) { gameState = GAME_OVER;} block.drawBlock(g); block.drawNextBlock(g);}// When the counter>=8, maxCounter will recount from zero clearing this.counter = 0;} else {block.paint(g); // its aim is to make the picture more smooth}} else if (gameState == GAME_OVER) { screen painting of game over} this.flushGraphics();//redraw in the buffer zone} protected synchronized void keyPressed(int keyCode) { int action = getGameAction(keyCode); if (gameState == HELP_MESSAGE) { if (action == Canvas.UP) {if (page > 0) { page--;}} if (action == Canvas.DOWN) {if (page < pagelong) { page++;}}} if (action == Canvas.LEFT && gameState == GAME_RUN) { if (this.block.checkMove(1)) { // move left block.move(1);} } else if (action == Canvas.RIGHT && gameState == GAME_RUN) { if (this.block.checkMove(2)) { // move right block.move(2);}} else if (action == Canvas.UP && gameState == GAME_RUN) { if (this.block.checkRot()) {// changing shape of the falling object block.rotBlock();}}
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else if (action == Canvas.FIRE && gameState == GAME_RUN) { while (block.checkDown(true)) { // falling rapidly this.block.down();} }} public synchronized void keyPressedState() { int keyState = getKeyStates();//actively inquiry state if ( (keyState & DOWN_PRESSED) != 0 && gameState == GAME_RUN) { if (this.block.checkDown(true)) { block.down(); } } } 3.2
Improve Square Changes Shape Algorithm
The main feature of Tetris game is to achieve eliminating the diamonds in the same line or the same row by combinations of different shapes of diamonds. The traditional way may define various of diamonds in advance, processing through choosing random numbers. This way can be used on a PC platform, because of PC’s incomparable processing speed and storage capability. But if this way is used on mobile phone platform, the processing speed will not be so satisfactory. In this paper, the new algorithm of changing diamonds is designed as follows: Defining a static array, and putting all shapes of diamonds by matrix method into this array. When the shapes of the diamonds change, we only need choose the corresponding matrix. The matrix representation is: 0 means the places without diamonds, while 1 means the opposite. Then we can use matrix to represent the shapes of diamonds. There are 7 kinds of diamonds in the game; each can have at most 4 different shapes. If we define a two-dimensional static array of 7*4 to store the shapes of diamonds, then we use the first dimension to mark the diamond type, while the second to mark the 4 shapes of diamonds. This method can make the changing shapes of diamond simpler, reduce the cost of the phone system, and improve game running speed. The old algorithm of processing diamond shapes needs more judgment and processing, and will increase the phone system cost and reduce game running speed. The disadvantage of this method is it needs define a more static array; it will increase the storage the game occupies.
4
Conclusion
This game uses J2ME technology, adopts JBuilder X development environment of BorLand Company. It uses the software engineering approach during design and development, and adopts the object-oriented language JAVA. As this game have a
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good foundation on the PCs and other consoles, this can be regarded as the transplant from PCs or consoles to mobile platform. The functions of this game are as same as those achieved on PCs and consoles, the game design mainly reflects the development and design of J2ME technology on micro-platform. The key of this design lies in it can be used very conveniently. The test result shows that, the design of this Tetris game has fast speed and stability.
References 1. Cai, C.-a., Qiu, Y.-d.: Design of Mobile Phone Game Based On J2ME. Computer Applications and Software (09), 45–54 (2008) 2. Su, Y., Lu, Y.: A Handset Map Inquiry System Based on J2ME Platform. Journal of Wuhan University of Technology (05), 120–127 (2007) 3. Chen, Q.-y., Wang, S.-z., Chen, T.-m.: A mobile phone game development based on J2ME. Journal of Yunnan University (S1), 45–52 (2007) 4. Zhang, X.-x., Lian, S.: New design and implementation of battle chess game based on J2ME. Computer Engineering and Applications (11), 124–128 (2011) 5. Zhang, X.-m., Jiang, S.-y., Jiang, L.-m.: Design and Implementation of mobile network games Based on j2me/socket. Microcomputer Information (36), 48–52 (2010) 6. Liu, G.-l., Qi, Z.-y., Zhang, H.-j.: Research and Design of Mobile Phone Games Based on J2ME Platform. Computer Programming Skills & Maintenance (18), 65–72 (2010) 7. Zhu, Q.-y., Zhang, S., Shen, J.-c.: Design and simulation of the BnB mobile games online based on J2ME. Journal of Shaanxi University of Technology (03), 67–74 (2010) 8. Zhao, L.-j., Zhu, Q.-y., Zhang, S.: Design and realization of mobile games online based on J2ME. Computer Engineering and Design (12), 84–89 (2010) 9. Jin, X., Yang, J.: The Analysis for Mobile Games Based on J2ME Platform. Computer Knowledge and Technology (12), 97–102 (2010) 10. Deng, Z.-r., Zhang, J.-w.: Design and Implementation of Mobile Phone Game Based on J2ME Framework. Computer and Modernization (09), 104–108 (2009)
Grid Service-Level Concurrency Control Protocol Chen Jun, Wang Jian-Ping, and Li Yan-Cui College of Information Engineering, Henan Institute of Science and Technology, Xinxiang Henan 453003, China {47594409,40376564}@qq.com, [email protected]
Abstract. In this paper, the grid real-time transaction model based on alternative service is defined. The model supports the joint implementation by a number of alternative services within one transaction, and allows grid services to join dynamically or exit the transaction’s execution. And then, the grid service-level (GSL) concurrency control protocol is proposed. In the database system environment, alternative services will not change the links between one real-time transaction and other real-time transactions; because of parallel execution, the likelihood of multiple services being restarted at the same time is very low. When a group of alternative services execute the same transaction, the service submitted is always the best and the fastest execution in a current system; execution of the transaction takes full advantage of the dynamic characteristics of grid service. Keywords: grid alternative service, GSL, Concurrency Control Protocol.
1
Introduction
With the maturity of grid technology and the deepening of real-time database, real-time database system in the grid environment started to become a new hotspot, and the transaction concurrency control has become one of the keys [1]. In real-time applications, the urgent task often has multiple alternatives to improve its success rate. In the grid environment, each alternative was performed by a service (called alternative service), so the real-time transaction is more adapted to the dynamic grid environment.
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The Model of Grid Real-Time Transaction
Definition 1: Task is defined as the collection of sub-transaction to complete a certain function. TS::={|1<=k<=n}
manipulation and transaction management operations).They are called the sub-transaction of original transaction. So the transaction is a nested structure. Tk ), Sub-service Tk consists of a group of alternative services{| (Tki 1<=i<=m}, each alternative service has the same function to Tk.
←→
Definition 2: A grid real-time transaction based alternative service can be formally defined as a quintuple: T::=< TS,R,C,F, T > Where, TS is a set of tasks, there is a specific caption as definition 1; R is the system resources what the execution of transaction is required, including the data to access, CPU time and buffers; C is the constraints that transaction must meet, including time constraints and consistency constraints; F is a set of grid services states, that the current grid services involved in the transaction of the active state (to join or quit);
﹤
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The Grid Service-Level Concurrency Control Protocol
Now, the existing alternative-level concurrency control protocols [2,3] are following to the principle of avoiding conflicts, and their practicality is not strong. Implementation modalities are serial, and the efficiency is low. In view of this, using dynamic grid and alternatives services, this paper proposed the grid service-level (GSL) concurrency control protocol. 3.1
Start Rule
Tn is a ready sub-transaction. When it received the scheduling of CPU, the discovery service to find m suitable alternative services Tnk (k = 1 ... m). During transaction, as the grid service exit independently, suitable alternative service can continue to join the sub-transaction if time allowed. Initialization Res (Tn), data set of Tn for the empty set; Res (Tnk), data sets of alternative service Tnk for the empty set; the completion identification of service F [n] [k] is 0, and the active identification of service L[n][k] is 1. 3.2
Write/Read Rule
In the grid Real-time database systems, the internal implementation of each sub-transaction Tn is a transparent, and detailed implementation process is as follows: When one of the alternative service Tnk wants to read / write data X, it must apply to their owner sub-transaction Tn for resources.
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At this point, if the data set Res (Tn) of sub-transaction Tn already stored data X, the sub-transaction Tn will agree an alternative transaction services Tnk to read data X, and the data X after read / write processing is added to the data set Res (Tnk) of Tnk. Otherwise, the sub-transaction apply for data X to the system. If the sub-transaction Tn applies for data successfully, the data is added to data sets Res (Tn), and m alternative services of the sub-transaction are allowed to use. 3.3
Commit Rule
In real-time transaction deadline, when one of alternative services Tnk first to complete all operations, its completion identification of service F [n] [k] is changged to 1, and it proposes to submit. If sub-transaction Tn agree, L [n] [j] (j≠ k) completion identification of others alternative services Tnk (whether or not conflict) becomes 0, and data of set Res (Tnk) coverage Res (Tn ). Everything is ready, the sub-transaction Tn go into the state of being allowed to submit. 3.4
Abort Rule
Even if all the alternative services of sub-transaction Tn died that L [n] [k] = 0 (k = 1 ... m), the sub-transaction Tn may not be aborted. If not near the deadline, sub-transaction Tn can still re-select the appropriate services to implement in the grid; otherwise, the sub-transaction Tn died[4,5].
4
The Petri Net of GSL Protocol and Analysis of Feasibility
4.1
The Petri Net of GSL Protocol
Assume that two arbitrary alternative services Tni and Tnj of one grid real-time transaction Tn, they completed read or write operation and conflict. At this point, the Petri net model of the conflict between two alternative services[6] as shown in Figure 1, the figure is described as follows:
Fig. 1. The petri net of GSL protocol: GSL-PN
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(1) The GSL protocol resolves the conflict optimistically.Therefore, there is no deadlock. If there is a read - write conflict between two arbitrary alternative services Tni and Tnj of one grid real-time transaction Tn, the two alternative services continue to execute concurrently. (2) If the alternative service Tnj submits before the deadline, Tni died.At the same time, the grid real-time transaction Tn submits. (3) If the alternative services Tnj and Tni aborted and the deadline of grid real-time transaction Tn is approaching, the Tn died. (4) If the alternative services Tnj and Tni aborted and the deadline of grid real-time transaction Tn is enough, Tn is to find suitable alternative services in the grid and to re-run. Because this situation and new services’ performing are exactly the same, we don’t to discuss it separately. The petri net of GSL protocol :GSL-PN=(P,T,F,W,M0),including[7,8]: P={S0,S1,…,S16} T={T1,T2,…,T15}(see Table 1) W={1,1,…,1} Table 1. The places and changes of GSL-PN Place S0 S1 S2 S3 S4 S5 S6 S7 S8 S9 S10
meaning
transaction Tn in initialization state
alternative service Tni in initialization state alternative service Tni in starting state alternative service Tni in execution state alternative service Tni in aborted state alternative service Tnj in initialization state alternative service Tnj in starting state alternative service Tnj in execution state alternative service Tnj in completed state alternative service Tnj in committing state the completed time of alternative service Tnj before deadline
change
T5
meaning transation Tn creates alternative serviceTni transation Tn creates alternative serviceTnj alternative service Tni initialization alternative service Tni writing/reading alternative service Tnj initialization
T6
alternative service Tnj writing/reading
T1 T2 T3 T4
T7 T8 T9 T10 T11
System events starting, alternative service Tni died System events starting,,alternative service Tnj di d alternative service Tnj committed,Tni died alternative service Tnj continue writing/ reading alternative service Tnj prepare to commit
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S11
System events which lead to alternative service to die is starting
S14
alternative service Tnj in aborted state the system time approaching deadline Transation Tn in aborted state
S15
Transation Tn in comimtting state
S16
Transation Tn in ending state
S12 S13
T12 T13 T14 T15
transation Tn prepare to commit transation Tn prepare to die transation Tn died transation Tn committed
F={(S0,T1), (S0,T2), (S1,T3), (S2,T4), (S3,T7), (S3,T9), (S4,T13), (S5,T5), (S6,T6), (S7,T8), (S7,T10), (S8,T11), (S9,T9), (S9,T12), (S10,T11), (S11,T7), (S11,T8), (S12,T13), (S13,T13), (S14,T13), (S15,T14), (T1,S1), (T2,S5), (T3,S2), (T4,S3), (T5,S6), (T6,S7), (T7,S4), (T8,S12), (T9,S4), (T10,S8), (T11,S9) , (T12,S15) , (T13,S14) , (T14,S16 ), (T15,S16)} Initial marking M0 there are two, corresponding to the following two situations: The grid real-tine transaction to submit: M0C=(2,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0) The grid real-tine transaction to die :M0D=(2,0,0,0,0,0,0,0,0,0,0,2,0,1,0,0,0) 4.2
The Analysis of Feasibility
GSL protocol Petri nets GSL-PN has two initial markers and corresponds to two different reachability trees: RTCC-PNCT (Figure 2) and the RTCC-PNDT (Figure 3).
Fig. 2. The transaction-submit tree of GSL-PN (GSL-PNCT)
Fig. 3. The transaction-die tree of GSL-PN(GSL-PNDT)
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Using the reachability tree analysis technique, we can see GSL protocol Petri nets GSL-PN with the following dynamic characteristics [9,10]: (1) GSL-PN in any one of the initial states is reachable. GSL-PN initial marking Mo={Moc,Mod }from the above reachability tree can be seen from the start of the Moc state of reaching set R(MoC)={ Moc, M1, M2,..., M26); start state can be Set up R(MoD)={MoD,M14,M16,M17,...,M51}. Therefore, R(Mo)= R(MoC)∪R(MoD)={MoC,MoD,M1,M2, ...,M51}.RTCC-PN of the state set MS={ MoC, MoD,M1,M2,...,M51}. Therefore, any mark Mi∈MS, both Mi∈R(M0), or either a GSL-PN state is reachable from M0. In other words, the Petri net is not an isolated dead or unwanted identity logo, which means that GSL protocol does not appear in the implementation process cannot be out of state or useless state. (2) GSL-PN is L1-live The reachability tree GSL-PNCT and GSL-PNDT of bounded GSL-PN contain all possible symbols. From the reachability tree, begin with M0, any Vti∈T (i=1,2,...,11) can be ignited at least once by some ignition sequence, that’s all the transition is L1-live. Therefore, Petri net GSL-PN is L1-live. The fact that the relative final state can be reached from some initial state M0 means no dead lock exists under any circumstance. All the transactions can be executed correctly. (3) Progress of GSL-PN One conclusion can be drawn from either the reachability tree GSL-PNCT or GSL-PNDT that, there’s no cycle between any two states. Therefore, any ignition will result in the system progressing towards a relative final state from the initial state. Accordingly, the algorithm won’t perform pointless actions during the execution. Therefore, at the same time with the nature of the five described by Petri nets GSL protocol is correct.
5
Conclusion
In this paper, it combines the dynamic nature of grid services with the capabilities’ alternative of real-time transaction. First of all, the grid real-time transaction model based on alternative service is defined .The model supports the joint implementation by a number of alternative services within one transaction, and allows grid services to join dynamically or exit the transaction’s execution. Secondly, the grid service-level (GSL) concurrency control protocol is proposed. In the database system environment, alternative services will not change the links between one real-time transaction and other real-time transactions; because of parallel execution, the likelihood of multiple services being restarted at the same time is very low. When a group of alternative services execute the same transaction, the service submitted is always the best and the fastest execution in a current system; execution of the transaction takes full advantage of the dynamic characteristics of grid service. Finally, the feasibility of GSL protocol is to be analyzed base on the formal Petri net.
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References 1. Taniar, D., Goel, S.: Concurrency Control Issues in Grid Databases. Future Generation Computure Systems 23(1), 154–162 (2007) 2. Xia, J.-L.: Conflict-Free Concurrency Control Protocol for Embedded Real-Time Database Systems. Journal of Computer Research and Development 41(11), 1936–1940 (2004) 3. Wang, S.-F.: The pre-analysis of embedded real-time transaction and research of concurrency control based on Alternative functional. Zheng Zhou Univercity, Zheng Zhou (2007) 4. Xia, J.-l., Han, Z.-b., Chen, H.: Conflict-free Concurrency Control Protocol Based on Function Alternative Model. Computer Engineering 36(15), 57–59 (2010) 5. Zhang, C.-q., Ma, J.-t.: Based on the alternative compensation study of real-time transaction scheduling algorithm. Manufacturing Automation 32(10), 116–118 (2010) 6. Murata, T.: Petri Nets: Properties, analysis and applications. Proceedings of the IEEE 77(4), 541–581 (1989) 7. Wu, Z.H.: Introduction to Petri nets. China Machine Press, Beijing (2006) 8. Yuan, C.-Y.: Theory and Application of Petri Nets. Publishing House of Electronics Industry, Beijing (2005) 9. Chen, J., Zhu, Y.-L., Gu, Y.-S.: A New Speculative Concurrency Control Protocol and The Analysis base on Petri Net. Computer Engineering and Applications 45(21), 121–123 (2009) 10. Chen, J., Gu, Y.-s.: A Grid Real-time Transaction Concurrency Control Protocol and The Analysis Based on Petri Net. Journal of Henan Normal University (Natural Science Edition) 39(01), 49–52 (2011)
Research of Serial Communication Module in Web Based on javax.comm Yan-pei Liu, Hong-yu Feng, and Jian-ping Wang Information Engineering College, Henan Institute of Science and Technology, xinxiang, 453003 [email protected]
Abstract. A novel serial communication mechanism, which suits for web, is designed and implemented by combining the special characteristics of serial communication module in Web based on javax.comm. It overcomes the defects existed in the occasions that the event-driven communication mechanism applied in web. It solves the data disorder when multiple users use the system simultaneity. The experimental result of the communication mechanism is given in order to prove the validity of this communication module. Keywords: serial communication, Web, data disorder.
Fig. 1. Event-driven mechanisms in the Web Application
Figure 1 is likely to happen: Servlet1 not receive data, but the serial data has been updated for response Servlet2, at this moment Servlet1 and Servlet2 get are Servlet2 write serial port returned to data, resulting in Servlet1 operation failure. Therefore, the design can adapt to Web[3] environment of serial communication mechanism, became the subject of research priorities, the following serial communication of new mechanisms designed to elaborate and test their effectiveness.
2
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Java communication API (referred to as Javax.comm.jar) is the standard J2SE extension, we use javax.comm.jar development package proposed a serial communication mechanism[4~6]. The newly proposed of serial communication mechanism focus on reading and writing of the serial port. The basic idea is: it will write the serial port and read unified in one function, that function completed with a serial read and write, write data as function parameters, receive data as a function of the return data: synchronized String WriteReceivePort (String str). Modify with the synchronized after the function for the synchronization function, when a thread using this method, the other thread if you want to use this method must wait until the thread is finished using this method. Send commands to the serial port directly through SerialPort the Write (byte[ ] b) function implementation; receive serial data but does not directly read back the serial port, and read from a buffer, the buffer data continuously by an independent thread read from the serial port, shown in Figure 2.
Fig. 2. Communication model
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Among them, read the serial port write buffer process shown in Figure 3. Serial read buffer reading process shown in Figure 4: In figure 3, read the thread to open the serial port write buffer to read data continuously from the serial port, if the data read is carriage returns, it is setting buffer can be read and arouse read buffer, otherwise read the data into a buffer, and then continue reading buffer. In figure 4, the system first determine the buffer is readable, if not readable, the system will wait for some time, and again to determine the buffer is readable, if readable, read buffer and wake-up write buffer threads, otherwise, the system default give up data directly awakened to the write buffer thread. Note that the reading is not a simple read, but after reading interception of the corresponding characters in the buffer, so the data in the buffer can only be read once.
Fig. 3. Reading the serial port write buffer process
3
Fig. 4. Reading the serial port read buffer process
The Key Code
The implementation of serial communication[7~9] mechanism mainly into three categories: SerialBean, SerialBuffer and ReadSerial. Among them, ReadSerial is a subclass of Thread, which is responsible for reading the serial port and reads of data writing buffer. SerialBean mainly responsible open the serial port and for initializationt of serial port, then activation of ReadSerial thread. SerialBuffer responsibility to read and write buffer.
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SerialBean class read the buffer ReadPort () and write WritePort (String Msg) are declared to be synchronized, to prevent causing read and write buffers confusion, read and write serial command SerialBean user interface is WriteReceivePort (String str). Code is as follows: public static synchronized String ReadPort() { String mstr=null; mstr = SB.GetMsg(); // read data from the buffer return mstr; } public static synchronized String WriteReceivePort(String str) { try { out.write(str.getBytes()); // Output stream object to serial write data }catch (IOException e){} try { Thread.sleep(800); } catch (InterruptedException e) { e.printStackTrace(); } String recvstr=ReadPort(); return recvstr; } SerialBuffer class method Read Buffer methods: public synchronized String GetMsg() { notifyAll(); if (Content.indexOf("\r")==-1) { available = false; while (available == false) { try { wait(60); if(available==false) { String s="No data received"; notifyAll(); return s;
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} } catch (InterruptedException e){ e.printStackTrace(); } } } int i=Content.indexOf("\r"); CurrentMsg = Content.substring(0, i); TempContent = Content.substring(i+1); Content = TempContent; notifyAll(); return CurrentMsg; } Write buffer function code is as follows: public synchronized void PutChar(int c) { Character d = new Character((char) c); Content = Content.concat(d.toString()); if (c==13) { available = true; //set buffer readable identification } notifyAll(); }
4
Testing and Experimental Results
According to the above design for the Web environment based javax.comm[10] serial communication mechanism, we carried out an effective test of the mechanism. In this test, program through the serial port continuously sends a series of instructions to the SR53, and receive the returned data. Part of the send command and the returned data communication protocols used are as follows:
① Read instruction data format: @ + address + command +: + parity bit + CR; ② Write instruction data format: @ + address + command + space + data 1, data 2, ... +: + parity bit + CR; ③ SR53 returns the same data format with ②. Among them, senddata [] is the input data, a, b are two parity bits. This test results shown in Figure 5:
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Fig. 5. Part of the communication data
In this mechanism, the serial read and write to be included into a synchronization function. When multiple users simultaneously on multiple clients the same operation, the system will automatically order more than one user's request, because "simultaneously" can only be relative, not absolute at the same time. In this way, multi-user operation to ensure the data is returned to its set or read the data, and data between multiple users will not be disorder problems.
5
Conclusion
This paper expatiated the serial communication mechanism for implementation based on event-driven, analyzed and summarized the shortcomings of this method, According to the characteristics of independent Web environment, design a Web environment of serial communication mechanism based on javax.comm, and gives this communication mechanism to realize the key code, the communication mechanism to make up for communication mechanism based on the event-driven the lack of Web environment application, to solve a number of simultaneous users the system disorder that occurs when the data problem, the final test of the communication mechanism and the experimental results.
References 1. Ma, Y.-c.: Java event-driven serial communication. Network & Communication, 54–56 (2007) 2. Qiang, Y.-t., Chen, H.-p.: New Event-driven Approach for Java Component Interaction. Computer Engineering (2007)
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3. Yang, T.: Research on Distributed Web Remote Monitoring System Based on Java Technology. Master’s Degree Paper, Nanjing University of Aeronautics and Astronautics, Nanjing (2008) 4. Liu, X., Hao, L.-n., Liu, B.: Design of Serial Communication Module in Ultrasonic Position System. Modern Electronics Technique (02) (2010) 5. Li, L., Zhu, S.-a.: Java-Based Implementation on Serial Communication. Chinese Journal of Electron Devices 30(2), 714–716 (2007) 6. Bian, X.-l., Wang, Y.-j.: Serial port communication between PC and NIOS II based on Delphi. Journal of Naval University of Engineering (05) (2008) 7. Dai, P., Liu, J., Fu, X.: Serial Communication Based on TMS320F2812 and LabVIEW. Computer Engineering 4 (2009) 8. Zhao, q.: The Study of the Bluetooth Protocol Stack and Its Application in Serial Communication. Master’s Degree Paper, Wuhan Institute of Technology, Wuhan (2009) 9. Han, B.-j., Lu, J.-h., Min, H.-s.: Design and implementation of serial communication model in WinCE. Computer Engineering and Design 08 (2008) 10. Wang, Z.-x., Xu, c., Wang, D.-f.: Method of multi-serial communication by using VC++ 6.0. Journal of Computer Applications s1 (2008)
Dynamic Invariance and Reversibility Preservation in Self-loops Connection of Petri Net Systems Fei Pu1,2 1
2
College of Computer and Information Engineering Zhejiang Gongshang University, China State Key Laboratory of Computer Science, Institute of Software Chinese Academy of Sciences, China [email protected]
Abstract. Petri net synthesis processes provide a solution for handling high complexity of analyzing large systems. These bottom-up techniques, consisting of sharing operation, synchronous operation, self-loops connection as well as inhibitor-arc connection, have the advantages of ease of system description and analysis since the properties of subsystems must be preserved in the synthesized system. This paper focus on the concurrent behavior relation in self-loops connection of Petri net systems. First, the property of dynamic invariance, reflecting the interaction of subsystems is discussed. Second, a necessary and sufficient criterion for the reversibility in self-loops connection is presented. Finally, some conditions for reversibility preservation are proposed. The advantages of our approaches are in the context of concurrent language and can synthesize Petri net systems beyond asymmetric choice nets.
1 Introduction Petri net system behavior depends on not only its graphical structure, but also on its initial marking, and it can be obtained through reachability analysis. The size of a reachability graph is determined by both the structure of system and the initial marking. In general, the larger structure of systems or the initial marking, the larger the reachability graph. And it has been shown that the complexity of the reachability analysis of Petri net system is exponential. Petri net systems composition can alleviate state space exploration by guaranteeing such good properties as liveness, deadlock-freeness, bounedness, reversibility and so forth while incrementally expanding the subsystems. Thus, composition operation is an effective way to manipulate systems of millions of states, and is playing an increasingly important role in theoretical and industrial fields. Normally, composition operations should obey the following three principles: 1. Preservation: The synthesized system should preserve some good properties. 2. Simplicity: The synthesis rules must be as simple as possible.
This work is supported by State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences under Grant No. SYSKF1011, the National Natural Science Foundation of China under Grant No. 61070059, National Basic Research Development Program of China(973 Program) under grant No.2009CB326204.
C. Liu, J. Chang, and A. Yang (Eds.): ICICA 2011, Part II, CCIS 244, pp. 408–417, 2011. c Springer-Verlag Berlin Heidelberg 2011
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3. Generality: The rules should be as powerful as possible to generate as many classes of system as possible. A lot of efforts has been done in this area. Wolfgang Reisig[1] provided the formal framework for a simple composition operator, adequate for many classes of Petri net applications. It requires a minimum of fairly intuitive technicalities from its users and readers. The modular state space technique[2] takes advantage of the modular organization of the model. Modular Petri nets consist only of modules synchronized through shared transitions. This modular approach can often decrease the complexity of the analysis task. A Petri net model is introduced in [3-4], which defines a set of basic subnets, namely elementary control tasks (ECT ). Such a model can be applied to design logic controllers by bottom-up approach, and the subnets are used to model subsystems through a number of connection operations including self-loops, inhibitor-arc, and synchronization. The liveness preservation of Petri net in above operations of are discussed. The work of H.Q.Wang[5] studied system behaviors, namely, language of firing sequences, and investigated system behaviors in the synthesis of Petri net models by using operations of self-loops, inhibitors as well as synchronization. But their approaches are only based on sequential language not on concurrent language. M.D.Jeng[6] proposed synthesis technique which allowed to model flexible manufacturing systems(F M S) guaranteeing property of liveness without posterior analysis. In his work, each subsystem is modeled as a resource control net module, and the net system is obtained by merging the modules conforming to two minimal restrictions and the system’s structural liveness is checked by an algorithm. The synthesis approach for modeling were described in [7]-[9]. These approaches can in fact guarantee the conservativeness of the synchronized net. The work of Aybar[10] proposed a decomposition technique with including principle which can be applied to decentralized control problem.
2 Basic Definition and Theorems A Petri net is a triple N = (P, T ; F ) such that P and T are disjoint finite sets, F ⊆ (P × T ) ∪ (T × P ) and dom(F ) ∪ cod(F ) = P ∪ T . The elements of P and T are respectively called places and transitions, and F is called the flow relation. The pair (N, M0 ) is a Petri net system, where M0 is the initial marking. Definition 1. Let Σ = (P, T ; F, M0 ) be a Petri net system, LS (Σ) = {α|α ∈ T ∗ and M0 [α >}, LS (Σ) is then called the sequential language of Σ or the sequential behav∗ ior of Σ, where T ∗ is the closure of T. Let LC (Σ) = {α|α ∈ (2T )∗ and M0 [α >}, LC (P N ) is called the concurrent language of Σ or the concurrent behavior of Σ, ∗ where 2T is the power set of T. Usually, for Rt ∈ 2T , if |Rt | = 0, Rt is called an empty step and denoted by Rt = λ. If |Rt | = 1, Rt is called a single step. If |Rt | > 1, Rt is called a concurrent step.
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A step Rt ∈ 2T is a set of transitions which can occur concurrently, For example, let Rt = {a, b},it means that transitions a and b can occur simultaneously. We also represent Rt as
a . b
Definition 2. Let L be a concurrent language of Σ. α, β are step sequences of L. We define two operations ”◦” and ”+” as following: α ◦ β ≡ αβ and α + β ≡ {α, β} Then the operation ”◦” and ”+” are called connection and addition operations respectively. Let Σ = (N, M0 ) be a Petri net system, where N = (P, T ; F ). Σ is reversible iff (if and only if): ∀M ∈ [M0 >, M0 ∈ [M >. It means that for any marking M reached from the initial marking M0 , then the marking M0 also can be reached from M . Definition 3. [12, 13] Let Σi = (Pi , Ti ; Fi , M0i )(i=1,2) be Petri net systems, P1 ∩P2 = ∅ and T1 ∩ T2 = ∅. Let Σ = (P, T ; F, M0 ) be a Petri net system such that 1) P = P1 ∪ P2 ; 2) T = T1 ∪ T2 ; 3) F = F1 ∪ F2 ∪ {(pi , t3−i ), (t3−i , pi )|pi ∈ Pi , t3−i ∈ T3−i , i = 1, 2 i.e. there is a self-loops between (pi and t3−i )}; 4) M0 (p) = M0i (p) if p ∈ Pi , i = 1, 2. Then Σ is called a self-loops connection net system with Σ1 and Σ2 , denoted by Σ = Σ1 Ol Σ2 . |∃p(3−i) ∈ P3−i such that (p(3−i) , ti ) ∈ F ∧ (ti , p(3−i) ∈ F, i = Let T0 = {t(i) ∈ Ti 1, 2} and T0i = T0 Ti (i = 1, 2). If t ∈ T0 , t is called a synchronous transition of T . Analogously, if t ∈ T0i , t is called a synchronous transition of Ti . Let Σ = (P, T ; F, M0 ) be a Petri net system. For ∀P ⊆ P , we represent M |P as a ∗ restriction of M on P . For ∀T ⊆ T , α ∈ (2T )∗ , we denote α|T as a restriction of α on T . Definition 4. Let Σi = (Pi , Ti ; Fi , M0i )(i = 1, 2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T, F, M0 ). ∗ 1) A step sequence α ∈ (2Ti )∗ is called a path on Σi , if ∃M, M ∈ [M0 > such that M [α > M . ∗ 2) A step sequence α ∈ (2T )∗ is called a path on Σ, if ∃M, M ∈ [M0 > such that M [α > M . ∗ ∗ 3) For an arbitrary path α1 ∈ (2Ti )∗ on Σi with α1 ∩ (2Ti )∗ = ∅, written as M1 [α1 > ∗ M2 , where M1 ∈ [M0 >, if there exists a path β ∈ (2T3−i )∗ on Σ3−i satisfying ∗ β ∩ (2Ti )∗ = ∅ such that: (1) M2 [β > M3 and ∗ (2) ∃Rt ∈ (2T0i )∗ , M3 [Rt >. then, α = α1 ◦Rt is called a basic synchronous path (BSP ) on Σi , β is called a mutual synchronous path (MSP) of α on Σ3−i , and α, β are called a pair of mutual synchronous paths on Σ. Let Rt = (α, β), then α can be represented by α = α1 ◦ (α, β) (note that α and β might be ε). ∗ 4) Let α be a path on Σi satisfying α ∩ (2T0i )∗ = ∅, α is called a basic nonsynchronous path (BN P ) on Σi .
◦ (α, β), α1 ◦ β ◦ (α, β). if α and β are a pair of MSP on Σ, written as α = α1 ◦ (α, β), (α1 and β can occur concurrently) if α and β are not a pair of MSP on Σ, 1) if α and β are BN Ps on Σi or Σ3−i ,
, α ◦ β.
λ. α β⊗γ
, α ◦ (β ⊗ γ).
α ◦ (β ⊗ γ). λ.
α⊗γ β
, (α ⊗ γ) ◦ β.
(α ⊗ γ) ◦ β. λ.
α⊗γ β⊗σ
1.1) if M[α > M1 ⇒ M1 [β > and M[β > M2 ⇒ M2 [α >, (α and β can occur concurrently) 1.2) if M[α > M1 ⇒ M1 [β > and M[β > M2 ⇒ ¬M2 [α >, (α and β occur in sequence) 1.3) otherwise, 2) if α, β are BN P and BSP on Σi or Σ3−i respectively, let γ is a MSP of β,
α ◦ β.
, (α ⊗ γ) ◦ (β ⊗ σ).
(α ⊗ γ) ◦ (β ⊗ σ). λ.
2.1) if M[α > M1 ⇒ M1 [β ⊗ γ > and M[β ⊗ γ > M2 ⇒ M2 [α >, 2.2) if M[α > M1 ⇒ M1 [β ⊗ γ > and M[β ⊗ γ > M2 ⇒ ¬M2 [α >, 2.3) if M[α > M1 ⇒ ¬M1 [β ⊗ γ >, 3) if α, β are BZOP and BN ZOP on Σi or Σ3−i respectively, let γ is a MZOP of α, 3.1) if M[α ⊗ γ > M1 ⇒ M1 [β > and M[β > M2 ⇒ M2 [α ⊗ γ >, 3.2) if M[α ⊗ γ > M1 ⇒ M1 [β > and M[β > M2 ⇒ ¬M2 [α ⊗ γ >, 3.3) otherwise, 4) if α and β are both BSPs on Σi or Σ3−i , let γ, σ be MSPs of α and β respectively, 4.1) if M[α ⊗ γ > M1 ⇒ M1 [β ⊗ σ > and M[β ⊗σ > M2 ⇒ M2 [α ⊗ γ >, 4.2) if M[α ⊗ γ > M1 ⇒ M1 [β ⊗ σ > and M[β ⊗σ > M2 ⇒ ¬M2 [α ⊗ γ >, 4.3) otherwise, ∗
5) if α ⊆ (2Ti )∗ ∪ (2 (2
α β
∗ T3−i ∗ ∗
, α ◦ β.
∗ T3−i ∗
)
∗
or β ⊆ (2Ti )∗ ∪
) , (both α and β consist of sequences f rom ∗ T3−i ∗
(2Ti )∗ and (2
α ◦ β. λ.
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) )
5.1) if M[α > M1 ⇒ M1 [β > and M[β > M2 ⇒ M2 [α >, 5.2) if M[α > M1 ⇒ M1 [β > and M[β > M2 ⇒ ¬M2 [α >, 5.3) otherwise,
Definition 5. Let Σi = (Pi , Ti ; Fi , M0i )(i = 1, 2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T, F, M0 ), and let α, β be two paths on Σ, then we define an operation ⊗ to represent the concurrent composition of paths on Σ shown as follows: Remark 1. 1) M ∈ [M0 >; 2) The definition is a recursive one since case 1) is applied to the latter cases; 3) We apply operation ” ⊗ ” to express concurrent composition of paths on Σ; 4) We provide two rules for calculus of paths on Σ as follows: 4.1)The operation degree of ” ⊗ ” is higher than ” ◦ ”; 4.2)The operation degree of ” ◦ ” is higher than ” + ”. Let Σi = (Pi , Ti ; Fi , M0i )(i = 1, 2) be Petri net systems, Σ = Σ1 Ol Σ2 = i T∗ ∗ (P, T, F, M0 ), (1) Let BM,M = {α ∈ (2 i ) |α is a BSP on Σi satisfying M [α >
i M , where M ∈ [M0 >}(i = 1, 2). BM,M represents the set of all BSPs on Σi from
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∗
i
M to M . (2) Let B M,M = {α ∈ (2Ti )∗ |α is a BN P on Σi satisfying M [α > M , i
where M ∈ [M0 >}(i = 1, 2). B M,M represents the set of all BN Ps on Σi from M i to M . (3) Let li (Σi ) = {BM,M |∀M ∈ [M0 >, ∀M ∈ [M >}, then li (Σi ) represents i
the set of all BSPs on Σi (i = 1, 2). (4) l i (Σi ) = {B M,M |∀M ∈ [M0 >, ∀M ∈ [M >}, then li (Σi ) represents the set of all BN Ps on Σi (i = 1, 2). Definition 6. Let Σi = (Pi , Ti ; Fi , M0i )(i = 1, 2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T, F, M0 ). 1) If each BN P on Σi can be extended to a BSP on Σi , then Σi is called a well Petri ∗ net system( W P N S ),i.e. for each BN P α on Σi , there exist α1 ∈ (2(Ti \T0 ) )∗ , Rt ∈ ∗ T ∗ 2 0i and β ∈ (2(T3−i \T03−i ) )∗ such that α ◦ α1 ◦ Rt is a BSP on Σi and β is its M SP . where ”\” is a subtract operation of sets. 2) If Σi is not W P N S, Σi is called an unwell Petri net system. Definition 7. Let Σ = (P, T ; , F, M0 ), be Petri net system and U,V the set of step sequences of Σ. If the language L(Σ) of Σ satisfies: L(Σ) = L(Σ) ⊗ U + V then this equation is called a recursive language equation of Σ or the language L(Σ) can be iteratively generated by this equation, where the initial value is L(0) (Σ) = {λ}. Example 1. : Σ is synthesized with Σ1 and Σ2 by two self-loops connections, shown by figure 1 (From left to right, they are Σ1 , Σ2 and Σ respectively).
Fig. 1. Σ is a self-loops connection net system with Σ1 and Σ2
It is easily known that the set of all BSPs on Σ1 is l1 (Σ1 ) = {a, da, cda, bcda} and the set of all BN Ps on Σ1 is l1 (Σ1 ) = {ε, b, c, d, bc, cd, bcd}. Similarly, it can be easy to verify that the set of all BSPs on Σ2 is l2 (Σ2 ) = {f, ef, hef, ghef } and the set of all BN Ps on Σ2 is l2 (Σ2 ) = {ε, e, g,h, gh, he, ghe}. From figure 1, we have α = a
b f e
cd abc is a sentence of LC (Σ) and it can gh
be shown that α = a ⊗ ε ⊗ b ⊗ ef ⊗ cda ⊗ gh ⊗ bc, where a ∈ l1 (Σ1 ), ε ∈ l2 (Σ2 ), b ∈ l1 (Σ1 ), ef ∈ l2 (Σ2 ), cda ∈ l1 (Σ1 ), gh ∈ l2 (Σ2 ), bc ∈ l1 (Σ1 ). Because
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α = a ⊗ ε ⊗ b ⊗ ef ⊗ cda ⊗ gh ⊗ bc = a ⊗ b ⊗ ef ⊗ cda ⊗ gh ⊗ bc = a ◦ b ⊗ ef
⊗ cda ⊗ gh ⊗ bc
b f ⊗ cda ⊗ gh ⊗ bc e
b =a◦ f ◦ cda ⊗ gh ⊗ bc e
b cd f◦ a ⊗ bc =a◦ e gh
b cd =a◦ f◦ a ◦ bc e gh
b cd =a f abc e gh =a◦
3 Dynamic Invariance and Reversibility in Self-loops Connection of Petri Net Systems The concept of dynamic invariance including state and behavior invariance was proposed in [13] on studying of synchronous and sharing synthesis processes. Their formal definitions are as follows: Definition 8. Let Σi = (Pi , Ti ; Fi , M0i ) (i=1,2) be Petri net systems, Σ = Σ1 OΣ2 = (P, T ; F, M0 ), where O is a synthesis operation. If ∀M ∈ [M0 >, M |Pi ∈ [M0i > (i=1,2), then the composite system Σ satisfies state invariance. Definition 9. Let Σi = (Pi , Ti ; Fi , M0i ) (i=1,2) be Petri net systems, Σ = Σ1 OΣ2 = (P, T ; F, M0 ), where O is a synthesis operation. If ∀α ∈ L(Σ), α|Ti ∈ L(Σi ) (i=1,2), then the resultant system Σ satisfies behavior invariance. In paper[5], it showed that the dynamic invariance holds in a synchronous synthesis process except for sharing process. We now show that the synthesized system Σ in self-loops connection with Σ1 and Σ2 also satisfies dynamic invariance. Theorem 1. Let Σi = (Pi , Ti ; Fi , M0i ) (i=1,2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T ; F, M0 ), then Σ satisfies state invariance. Theorem 2. Let Σi = (Pi , Ti ; Fi , M0i ) (i=1,2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T ; F, M0 ), then Σ satisfies behavior invariance. To present a sufficient and necessary criterion for reversibility in self-loops operations, we need to introduce some new concepts: Definition 10. Let Σ = (P, T ; F, M0 ) be a Petri net system, X be a T -invariant (i.e. DX = 0, where D is incident matrix of Σ) and X > 0. Let X = {ti |ti ∈ T and X(i) > 0}, then X is called the support of X.
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Definition 11. X is called a minimal support of T -invariant iff there exists no T invariant X (X = X) such that X ⊆ X . X is called a minimal T -invariant iff X is a minimal support of T -invariant and there exist no minimal support of T invariant X (X = X) such that X < X.
X < X means that each component of X is less than its corresponding component of X, and there exist at least one component of X which is strict less than its corresponding component of X. Lemma 1. Let Σ = (P, T ; F, M0 ) be a Petri net system, if Σ is reversible, then there exists X > 0 such that DX = 0. Definition 12. Let Σ = (P, T ; F, M0 ) be a Petri net system, X be a minimal T ∗ invariant of Σ. If there exists α ∈ (2T )∗ such that M0 [α > M0 and (ti /α) = X(i), where (ti /α) represents the occurrence number of ti in α, i = 1, . . . , |T |, then α is called a minimal reversible path with respect to X. If only M0 [α > M0 holds, then α is called a reversible path. Definition 13. Let Σi = (Pi , Ti ; Fi , M0i ) (i=1,2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T ; F, M0 ), P (Σi ) is the set of all minimal reversible paths in Σi , the set P (Σi ) can be in the following two cases: ∗
PU = {α|α ∈ P (Σi ) and α ∩ 2T0 = φ} ∗
PV = {α|α ∈ P (Σi ) and α ∩ 2T0 = φ} Definition 14. Let Σ = (P, T ; F, M0 ) be a Petri net system, if there is a vector Y > 0 such that DY = 0 and Y ⊂ X for all minimal T -variant X, then Y is called an ∗ irreversible vector. If there exists α ∈ (2T )∗ such that M0 [α > and (ti /α) = Y (i), where Y is an irreversible vector, i = 1, . . . , |T |, then α is called an irreversible path with respect to Y . Lemma 2. Let Σ = (P, T ; F, M0 ) be a Petri net system. 1) Σ is reversible iff there is no irreversible path in Σ. 2) Σ is irreversible iff there is at least an irreversible path in Σ. Definition 15. Let Σ = (P, T ; F, M0 ) be a Petri net system, for any step sequence ∗ α ∈ (2T )∗ , let pref (α) = {α |α = α ◦ α , α might be ε}, then pref (α) is called prefix set of α, α is prefix sequence of α. Theorem 3. Let Σi = (Pi , Ti ; Fi , M0i ) (i = 1, 2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T ; F, M0 ), Σ is reversible iff one of the following three cases holds: Case A: 1) Both Σi (i = 1, 2) are irreversible, and for any irreversible path α(i) ∈ L(Σi ) (i = 1, 2), there exists no α(3−i) ∈ L(Σ3−i ) such that α(i) ⊗ α(3−i) = ε. 2) For ∀α(i) ∈ P (Σi ), ∀α(3−i) ∈ PU (Σ3−i ), (i = 1, 2), if α(i) ⊗ α(3−i) = ε, then for ∀β (i) ∈ pref (α(i) ), ∀β (3−i) ∈ pref (α(3−i) ), β (3−i) = α(3−i) , β (3−i) = ε, it
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holds that for ∀σ (3−i) ∈ P (Σ3−i ) with σ 3−i = α(3−i) , if β (3−i) ∈ pref (σ(3−i) ), then β i ⊗ β (3−i) = ε. (i) (i) (i) (3−i) (3−i) (3−i) α2 . . . αm such that 3) there exists αi = α1 α2 . . . αm and α3−i = α1 (i) (3−i) (i) (3−i) = ε, where αj ∈ P (Σi ) (j = 1, . . . , m), αk ∈ P (Σ3−i ) (k = α ⊗α 1, . . . , n) and α(i) or α(3−i) might be ε (i = 1, 2). Case B: 1) Σi is reversible, but Σ3−i is not (i = 1, 2), and for any irreversible path α(3−i) ∈ L(Σ3−i ), there exists no α(i) ∈ L(Σi ) such that α(3−i) ⊗ α(i) = ε. 2) For ∀α(i) ∈ P (Σi ), ∀α(3−i) ∈ PU (Σ3−i ), (i = 1, 2), if α(i) ⊗ α(3−i) = ε, then for ∀β (i) ∈ pref (α(i) ), ∀β (3−i) ∈ pref (α(3−i) ), β (3−i) = α(3−i) , β (3−i) = ε, it holds that for ∀σ (3−i) ∈ P (Σ3−i ) with σ 3−i = α(3−i) , if β (3−i) ∈ pref (σ(3−i) ), then β i ⊗ β (3−i) = ε. (i) (i) (i) (3−i) (3−i) (3−i) α2 . . . αm such that 3) there exists αi = α1 α2 . . . αm and α3−i = α1 (i) (3−i) (i) (3−i) α ⊗α = ε, where αj ∈ P (Σi ) (j = 1, . . . , m), αk ∈ P (Σ3−i ) (k = 1, . . . , n) and α(i) or α(3−i) might be ε (i = 1, 2). Case C: 1) Both Σi (i = 1, 2) are reversible. 2) For ∀α(i) ∈ P (Σi ), ∀α(3−i) ∈ PU (Σ3−i ), (i = 1, 2), if α(i) ⊗ α(3−i) = ε, then for ∀β (i) ∈ pref (α(i) ), ∀β (3−i) ∈ pref (α(3−i) ), β (3−i) = α(3−i) , β (3−i) = ε, it holds that for ∀σ (3−i) ∈ P (Σ3−i ) with σ 3−i = α(3−i) , if β (3−i) ∈ pref (σ(3−i) ), then β i ⊗ β (3−i) = ε. (i) (i) (i) (3−i) (3−i) (3−i) α2 . . . αm such that 3) there exists αi = α1 α2 . . . αm and α3−i = α1 (i) (3−i) α(i) ⊗ α(3−i) = ε, where αj ∈ P (Σi ) (j = 1, . . . , m), αk ∈ P (Σ3−i ) (k = 1, . . . , n) and α(i) or α(3−i) might be ε (i = 1, 2).
4 Reversibility Preservation in Self-loops Connection Processes The reversibility preservation guarantees that the reversibility of subsystems make the reversibility of the global system. Definition 16. Let Σ = (P, T ; F, M0 ) be a Petri net system, if for t ∈ T , there exists t ∈ T (= t) such that • (t ) =• t, (t )• = t• , then t is called a substituted transition of t. Theorem 4. Let Σi = (Pi , Ti ; Fi , M0i ) (i = 1, 2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T ; F, M0 ). If the following conditions hold, then Σ is reversible. 1) Σi (i = 1, 2) are reversible. 2) for ∀α ∈ PU (Σi ) (i = 1, 2), then all synchronous transitions in α have their substituted transitions and there is at least one substituted transition is not synchronous transition.
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Theorem 5. Let Σi = (Pi , Ti ; Fi , M0i ) (i = 1, 2) be Petri net systems, Σ = Σ1 Ol Σ2 = (P, T ; F, M0 ). If the following conditions hold, then Σ is reversible. 1) Σi (i = 1, 2) are reversible. 2) all synchronous transitions of Σi (i = 1, 2) are in the minimal reversible pathes of Σi . 3) there is at most one self-loop arc between an arbitrary minimal reversible path in Σi and an arbitrary minimal reversible path in Σ3−i . Two minimal reversible pathes connected with each self-loop arc are not the same pathes, and moreover, the synchronous transitions connected with each self-loop arc are not the same transitions.
5 Conclusions Reversibility is a very significant property of systems which represents the ability of systems returning to the initial marking from any marking reached from an initial marking. Usually, reversibility analysis is performed using reachability graph reduced by stubborn sets. Due to the explosion problem of the state space of reachability graph, the production of the minimal reachability graph by stubborn sets is also a NP-hard problem. Compositional methods provide a solution to alleviate the large state space that needed to be explored when analyzing such properties as reversibility, liveness, and deadlock-freeness etc, of large systems. This paper focus on reversibility preservation in self-loops connection operations, the methods are based on concurrent language not on sequential language [14]. We present an operation ”⊗” to express the concurrent composition of paths and establish a recursive language equation to judge the reversibility of synthesized system. We also demonstrate an important property, namely, dynamic invariance, in self-loops operations. Moreover, we propose a criterion, which is sufficient and necessary for reversibility of global system and present some conditions to preserve reversibility in self-loops connection processes. One of the main advantages of our approaches is that we can synthesize Petri net systems beyond asymmetric choice net systems. In particular, the approaches presented here can easily be generalized to Petri net systems with weighted arcs.
References 1. Reisig, W.: Simple Composition of Nets. In: Franceschinis, G., Wolf, K. (eds.) PETRI NETS 2009. LNCS, vol. 5606, pp. 23–42. Springer, Heidelberg (2009) 2. Christensen, S., Petrucci, L.: Modular analysis of Petri nets. The Computer Journal 43(3), 224–242 (2000) 3. Ferrarini, L., Narduzzi, M., Tassan-Solet, M.: A new approach to modular liveness analysis conceived for large logic controllers’ design. IEEE Transactions on Robotics and Automation 10(2), 169–184 (1994) 4. Ferrarini, L.: An incremental approach to logic controller design with Petri nets. IEEE Transactions on Systems, Man, and Cybernetics 22(3), 461–473 (1992) 5. Wang, H.Q., Jiang, C.J., Liao, S.Y.: Behavior relations in synthesis process of Petri net models. IEEE Transsactions on Robotics and Automation 16(4), 400–406 (2000) 6. Jeng, M.D.: A Petri net synthesis theorey for modeling flexible manufacturing systems. IEEE Transactions on Systems, Man, and Cybernetics 27(2), 169–183 (1997)
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7. Jeng, M.D.: A Petri net synthesis theory for modeling flexible manufacturing systems. IEEE Trans on systems, Man, and Cybernetics-Part B:Cybernetics 27(2), 169–183 (1997) 8. Jeng, M.D., Diceare, F.: Synthsis using resource control nets for modeling share resource systems. IEEE Trans on Systems, Man and Cybernetics 11(3), 317–327 (1996) 9. Ferrarini, L., Trioni, M.: Modeling shared resources with generalized synchronization within a Petri net bottom-up approach. IEEE Transactions on Systems, Man, and Cybernetics-Part B: Cybernetics 26(45), 653–659 (1996) 10. Aybar, A., Ifar, A.: Overlapping decompositions and expansions of Petri nets. IEEE Transactions on Automatic Control 47(3), 511–515 (2002) 11. Xing, K.Y., Hu, B.S., Chen, H.X.: Deadlock avoidance policy for Petri net modeling of flexible manufacturing systems with shared resources. IEEE Transactions on Automatic Control 41(2), 39–45 (1996) 12. Murata, T.: Petri nets: properties, analysis and applications. Proceedings of the IEEE 77(4), 541–580 (1989) 13. Jiang, C.J.: A PN machine theory of discrete event dynamic system. The Science Press, Beijing (2000) 14. Ding, Z.J., Jiang, C.J., Zhou, M.C., Zhang, Y.Y.: Preserving languages and properties in stepwise refinement-based synthesis of Petri nets. IEEE Transactions on Systems, Man, and Cybernetics-Part A: Systems and Humans 38(4), 791–801 (2008)
Study on the Key Technology of News Collection and Release System Based on Java Hong-yu Feng, Yan-pei Liu, Yan-cui Li, and Quan-rui Wang Henan Institute of Science and Technology, Information and Technology College, Xinxiang City, Henan Province, China [email protected], [email protected], [email protected]
Abstract. To improve news collection and release efficiency, the study designs a news collection and release system which can realize cross-platform running and automatic collect news. The system adopts java, J2ee and Mysql technology to develop. The system includes five modules. In the process of design, considering the security and convenience of customers use, the design studies on some key technology of the system. They are login security question, paging technology and messy code processing. The thesis analyzes the reason of these questions in detail and gives solutions. The solving codes are listed. Via testing, the solutions solve these questions well. Keywords: news collection, login, paging technology, messy code processing.
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Introduction
Along with the rapid development of computer technology, its application has permeated the various fields of social life. Faced with large of news in the internet, news collection and release is the thing that website managers often do. But at present the news collection and release system mostly needs manual entry news content, and can not use on cross-platform. So it is not convenient when faced with large of news contents entry and run on different operating system platform. The design makes up these defects and it improves work efficiency. The paper analyses and discusses the key technology to give a reference to developers.
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Fig. 1. The news collection and release system includes five modules
The paper analyses and discusses the login technology, paging technology and messy code processing technology.
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As an application of b/s structure, firstly a friendly man-machine interaction interface is needed. The system adopted JSP technology of J2ee. But considering that the login interface to the function is not high, the interface can be static page. The module function realization process is as figure 2.
Fig. 2. Login module procedure. User need input right user name and password to enter system. If user name or password is not right, program returns to login interface. If user try to input IP address in IE address bar directly, program return to login interface as same.
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All input interface are written in form, which is used to submit foreground input data to actionserverlet. On the basis of form attribute of foreground interface, the design set two attributes------user and name------the two attributes write into actionform. Then submit the form action in login.jsp to actionservlet, in the same time struts framework can automatically encapsulate foreground data to corresponding loginform. Loginform take out the attributes of form to get name and password, then connect to database to conduct authentication. The database use not SQL but HQL. HQL and SQL is similar but HQL does not need write “select *”. This design add enterprise technology Hibernate framework, so POJO, that is a persistent class, not table name is written behind “from”. In this method the operation of the table will be turned to the class of operation which simplify program. In order to prevent user who input directly address in IE address enter background to operate, the design conduct The authority processing, it put user name of login into session and import filter into program. Whatever user do, program take IE address from filter and read user name from session. If session is null, it indicates that user try to enter background directly, program refuse and return to login interface; and if not, it suppose normal login and admit to enter into background to operate.
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As data which are going to display is much, if they display on the foreground interface one at a time, there are several faults. Firstly, it is not convenient for user to look up. Secondly, server load is too heavy if it read mass data one at a time. So the program writes a common module of paging. In the module the program read ten data one at a time and read data from database bathing. The key code is as follows. public class Pager { private int totalRows; private int pageSize = 10; private int currentPage; private int totalPages; private int startRow; public Pager(){} public Pager(int totalRows){ this.totalRows = totalRows; totalPages = totalRows/pageSize; int mod = totalRows % pageSize; if(mod>0){ totalPages += 1; } currentPage = 1; startRow = 0; } public void first(){ currentPage = 1; startRow = 0; } Public voidl last(){currentPage =totalPages; startRow = (currentPage-1)*pageSize; } public void previous(){ if(currentPage ==1){ return ; }
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currentPage--; startRow = (currentPage-1)*pageSize; } public void next(){ if(currentPagetotalPages){ last(); } } The pager class is used to compute the start line of home page, previous page, next page and last page. But only the class can not complete all work. The program need get some paging data from foreground, use relate method of background and introduce different parameters. So the program design a paging auxiliary class, its key codes is as follows: public static Pager getPager( HttpServletRequest request, int totalRows){ Pager pager = new Pager(totalRows); String currentPage = request.getParameter("currentPage"); if(currentPage != null) pager.refresh(Integer.parseInt(currentPage)); } String pagerMethod = request.getParameter("pageMethod"); if(pagerMethod != null){ if(pagerMethod.equals("first")){ pager.first();} if(pagerMethod.equals("next")) { pager.next();} … } return pager; } In such, when submitting form request, the program can call code of background taking different parameters after URL. In DAO layer, the program utilize hibernate function, which can set record quantity and starting position of every time to confirm how much records. Its codes are as follows: q.setFirstResult(startRow); q.setMaxResults(pageSize); Then the program put require results into list, and take the list to foreground interface, expand the list via logic label of struts and then user can look up data. The code is as follows. The common paging module has been realized. When other modules need use the paging function, they can call related method and afferent different parameters.
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${one.id}
${one.name}
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Messy Code Processing
In b/s system messy code processing is a common question. The system use MYSQL as database, MYSQL use Lantin as coding, but the system use GBK as coding. The two coding is not disunity, there must be appear messy code. In order to solve the question, the program import filter to process messy code question. The key code is as follows. public class SetCharacterEncodingFilter implements Filter { private String encoding = "GBK"; public void destroy() { } public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException { req.setCharacterEncoding(encoding); chain.doFilter(req, resp); } public void init(FilterConfig config) throws ServletException { String encodeName = config.getInitParameter("encoding"); if (encodeName != null && encodeName.length() > 0) { encoding = encodeName; } } At the same time, the program need configure the filter class into web.xml file. Each operation of system request must go through the filter and page code is turned into GBK. That is to say when user submits data to database, the program set data code to GBK. On the contrary, the content read from database is filtered GBK to display.
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The news collection and release system is based on Struts and Hibernate framework technology of J2ee, it realized news collection, release function and management function etc. the advantage of design is run on different operating platform. Via testing, the system can collect RSS channel of Sina web automatically in short time. It makes up the complexity of manual entry news and improves work efficiency. In the process of the design, the thesis put emphasis on some key technology, such as security login technology, paging technology and messy code processing etc. The thesis analyze the reasons of these question and solve these questions finally. Via the discusses of the thesis, the common question is solved and it is a reference to software developers.
References 1. Zhang, X.-x.: Java Teaching Tutorial for Obtaining Employment, vol. 5. Qinghua University Press, Beijing (2006) 2. Zhou, X.-y.: Office Infomatization. Design and Java Implementation of General Permission Management System 2 (2011) 3. Li, B.-w.: Discuss the Security Question of Login Utilizing Java Web. Public Communication of Science and Technology 1 (2011) 4. Yin, H.: Java and Oriented Object Program Designing, vol. 4. Higher Education Press, Beijing (2004) 5. Zhang, Y., Li, Q.-s., Zhang, Y.: The Resolving of Javabean in JSP Page Designing. Shanxi Engineering College Journal 01 (2005) 6. Song, G.-c., Yang, H.-q., Zhao, G.-s.: The Application and Realization of MySQL Database in Domain Name System. Microcomputer Applications 3 (2010) 7. Liu, Y., Zhang, J.-p., Wang, N.: Design of Java-based Book Query. Computer Development and Applications 2 (2011) 8. Lu, D., Li, S.-p., Zheng, C.-z.: Extended Java Collection Framework Based on Objectedoriented Database. Computer Applications and Software 1 (2011) 9. Jiang, L.-q.: ava Network Programming Example Course, vol. 1. Qinghua University Press, Beijing (2005) 10. Yuan, H.-y.: JAVA Application Programm Designing 100 Example, vol. 5. People’S Telecommunication Press, Beijing (2005)
A Living Time-Based Parallel Multi-Path Routing Algorithm for Mobile Ad Hoc Networks Min Huang, Hong Li, and Qinpei Liang School of Software Engineering, South China University of Technology, Guangzhou 510006, China {Min Huang,Hong Li,Qinpei Liang,LNCS}@Springer.com
Abstract. To reduce route coupling and improve reliabilities of transmitting paths in wireless mobile ad hoc networks, a parallel multi-path routing algorithm called LT-PMPRA is proposed in the paper. It takes the living time based on power factors of nodes and links as the routing parameters to solve the problems of mobility and limited power of nodes, and uses two iterative factors in the multi-path selecting processes based on a modified Dijkstra' algorithm to find different node-disjointed or link-disjointed paths, by which to enhance the transmitting efficiency of parallel paths. The main data models and key algorithm of LT-PMPRA are given in the paper in detail, and two types of simulation experiments are done to verify the validities of the algorithm. It is showed that LT-PMPRA can improve obviously the stabilities and disjointedness of paths. Keywords: Multi-path routing algorithm, Living time, Parallel, Disjointed, Ad hoc network.
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route maintenance processes between source node and destination node. Neither there is periodic broadcast routing information, nor requiring the link to be bi-directional, so that the failure link cannot be repaired locally during the route maintenance, and failure link information must be returned to the source point. Aiming at the problems above, a hybrid multi-path algorithm named LT-PMPRA is proposed in the paper, which is based on Optimized Link State Routing (OLSR) [9] and evaluation of living time for links and nodes. The algorithm adopts link state, assessment factors of node energy and iterative factors to find multiple parallel and disjoint paths, and the details of the algorithm are introduced as follows.
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Descriptions of the Algorithm and Its Data Models
LT-PMPRA is a hybrid routing algorithm similar to the proactive routing algorithm, but it does not require each node of the network to maintain a routing table of all other nodes and periodically update the routing table, and it merely exchanges information before routing. LT-PMPRA includes steps such as discovering neighbors, apperceiving links, constructing link state information, diffusing information and calculating route, which can be described as follows: nodes periodically construct LSP (Link State Packet) which includes the living time of neighbors and corresponding links connected, and then spread it to other nodes in the network by flooding. When other nodes receive the LSP, they will save it to the local NLS (Network Link Set) firstly, and then construct the network topology and calculate the iteration factor when they want to find paths to transmit information, by which they can get multiple paths by using LTPMPRA. The paths information will be stored in the packet header by the source node of the path and there is no need for the intermediate nodes to calculate hop-by-hop routing during the process of data transmitting. So LT-PMPRA not only inherits the advantages of the link state algorithm such as having smaller network latency and stability, but also reduces the numbers of link state packets which flood in the network and calculating costs of intermediate routing nodes. The main data models used in the LT-PMPRA are introduced as follows. 2.1
HELLO Message and Topology Control Message
Firstly, the HELLO message packet transferred between two adjacent nodes includes information such as length of packet, sequence number, effective time, sender, transferring period and other basic fields, and it also includes some fields that will be used for the following routing process such as the identifier of being the MRP of one neighbor, the link set, the neighbor node set, the MPR set, and so on. Secondly, the topology control (TC) message transferred among the non-adjacent nodes contains the information about the sender and the neighbors of the sender, and will be broadcasted to the entire network. To satisfy the limitations of message length in the network, when there are a lot of adjacent nodes, the TC message will be divided into several packets and sent in an update period.
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To Trace and embody the changes of the network topology and the link availability, the LT-PMPRA adds two information fields as living times of node and link based on energy factor of them into the HELLO message and TC message. Abstracting Ad hoc network as a directed graph model G = (V, E), where V is the finite set of mobile nodes, E is the finite set of wireless link edge, (xi, yi) is the coordinate of mobile node i in the network, vi and θ i are the moving speed and moving direction in the network, Ri is the effective transmitting radius of node i, the living time of links and nodes as calculated as formula (1) and (2): a. TLij is the living time of the link between node i and node j T L ij =
(a 2 + c 2 )r 2 - (a d - b c ) 2 a2 + c2
-(a b + c d ) +
(1)
a = vi cosθ i - v j cosθ j ;b = xi - x j c = vi sinθi - v j sinθ j ; d = yi - y j r = Ri b. TNi is the living time of the node i with energy factors If the Ad hoc network nodes have different transmission power, but do not have the ability of adjusting the power, the sending power of node i to all of the adjacent nodes which are in its transmission radius Ri are ei. When the remained energy of node i is ei, we can get the living time TNi showed as formula (2) [7], in which the fij is the data flow sending from node i to node j. TNi = Ei
2.2
/ ei fij j∈Ni
(2)
Sets of Neighbors, Links and Topologies and Routing Table
The set of neighbors of one node contain the information of its one-hop and two-hop neighbors such as names, address, which will be refreshed periodically by the HELLO message. The set of links of one node contain status information of all links to or from the node such as node address, survival period, and communication mode of the link (unidirectional or bidirectional). And it is built by periodically exchanging HELLO message among adjacent nodes, in which the unidirectional mode means that the communication between one node and its adjacent node is not symmetric, that is, it can receive HELLO message from its adjacent nodes but not ensure that its adjacent nodes can receive HELLO message from itself; while the bidirectional mode means that two adjacent nodes can exchange message from each other. The set of topologies of one node contain the TC messages that are sent by nonadjacent nodes. Each field in the topology table contains the information of a received TC message such as sequence number, receiving time, sender, the one-hop neighbors, and so on.
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By the data sets above, we can concstruct the whole topology of network. For both of the neighbors set and links set are constructed by HELLO messages, to reduce the number of the flooding link state packets (LSP), a flooding method named LSP which based on SR (Selective Relay) has been presented there, in which only parts of the neighbors of a node with some conditions as follows are chosen as the SR (Selective Relay) to retransmit the LSP: 1) It should be the one-hop symmetric neighbor of the node, which means the link between them is bidirectional and they can exchange message); 2) the set of forward one-hop neighbors of SR should cover all of the symmetric two-hop neighbors of node i, so each node in the network will either has its own SR set or be the SR of other nodes at the same time. The method above can be implemented by maintaining a table of SR set and a table of selected SR set in each node, the former records the neighbors that will transmit the LSP of the node, and the latter records the adjacent nodes whose LSP will be transmit by the node. By this way, it can reduce the transmitting number of the LSP in the same area effectively, and reduce the costs of the network routing consequently. Routing table is the core data structure of each node. When there is a routing request, multiple disjoint paths from one node to a given destination node can be calculated by the multi-path routing algorithm proposed in the paper, and the paths information, routing validity time, time tag and other information will be stored into both of the routing table and packet header by source routing way. When the intermediate nodes receive the packet, they only need to check the header’s source routing information and then transmit the packet again.
3
Details of the LT-PMPRA Routing Algorithm
Besides of taking the living time of nodes and links into account in the paths selecting to ensure that the paths selected have longer living time so as to reduce update times of routing and avoid the failure of whole path for the energy exhausting of some certain links or nodes, LT-PMPRA also uses some methods to reduce the intersection of parallel paths to improve data transmission efficiency. On the base of living time of links and nodes, some iterative factors are brought to an improved Dijkstra’ algorithm to find some disjointed multiple paths, and the details of the routing algorithm are introduced as follows. 3.1
Modified Dijkstra Algorithm Based on Living Time of Nodes and Links
In the process of route calculating of LT-PMPRA, a modified Dijkstra algorithm named Dijkstra’ has been proposed in the paper, which finds paths with the highest stability from s to d using not length of path but the living time of nodes and links. Assuming that the source node is called s and the destination node is called d, and the energy graph G’= (V, E) which adds TNi and TLij into directed graph G has been constructed and stored in each node by exchanging periodically of HELLO message
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and TC message above, then the Dijkstra’ algorithm will be executed to find path in each node by following steps: Dijkstra’(G’, s){ X={s}; Y=V-{s}; Z={}; v=s; while Y ≠ {} do { m1=max{TLvj|j∈Neighb(v) and j∈Y} M1={|i∈Neighb(v) and i∈Y, TLvi=m1 } M2={ j| ∈M1}; m2=max {TNj|j∈M2}; if |M1|=1 then { X=X+M2; Y=Y-M2; Z=Z+M1; TLvi=min{TLij|∈Z}; v=i; } else{ M2={ j| TNj=m2 and j∈M2}; k=ChooseOneElem(M2); X=X+k; Y=Y-k; Z=Z+{}; TLvi=min{TLij|∈Z}; v=k; } } return Z; } Firstly, the network topology graph and three types of set as X, Y, and Z are initialized. The set of X include all of the extended nodes, and contain only source node s initially, and a new node will be added into it in each step until all of the nodes in the graph have been in it; the set of Y include unexpanded nodes initially, and a node will be moved out of it in each step until it has become empty; the set of Z include all the most stable links selected from s to d, and it is empty initially and add a new link in each step. Secondly, after the initialization above, the following three steps will be executed repeatedly until all the nodes of graph G’ are included into the set of X: 1) Selecting the link having the maximum living time from all the output links which start from the node v, which will be the source node s at the beginning; 2) If there are several links which have the same maximum living time of link, then comparing the living time of neighbor in each link, and selecting the link with neighbor having the maximum living time; 3) If there are several links with the same maximum living time of link and corresponding node living time of its neighbor, selecting any of them. When a link has been selected into the set of Z in the step 2) and 3) each time, the corresponding node will be added to the set of X, and by this means, the sets of X and Z will be expanded, and then the most stable path from s to d will be included in set of Z finally. 3.2
Multi-path Routing Algorithm with Iterative Factors
LT-PMPRA finds multiple paths by using iteratively the Dijkstra' algorithm above many times. During the iteration process, the weights of links and nodes which
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included in the paths are adjusted by the iterative factors. It results in several different paths with descending stability. The algorithm is described as follows: for ( i=1; i<=m; i++) PathSinkTreei= Dijkstra’(G’, s); Pi=GetPath(PathSinkTreei, s, d); E=GetEdges(Pi); V=GetVertex(Pi); ∈ E do for TLij= (1-α) TLij ; end for i∈ V do for TNi= (1-β) TNi; end for end for return (P1,P2,P3,…,Pm)
∀ ∀
In the algorithm above, if a stable path Pi from s to d has been gotten in the i’th iteration process by Dijkstra' algorithm, then it will reduce the living time of links and nodes which are included in the path Pi in the next i+1’th iteration process, by which to reduce the possibility of reuse of those links and nodes in the Pi+1, and make the stable path Pi+1 be different from Pi. The iteration factor α and β in the algorithm above are the factor for adjusting weights of link and node. Both of their value are ranged in scope of [0, 1] and can be expressed as formula (3).
α=
TL max
- TL min
TL aver
β= and
TN vi
- TN thrd
TN thrd
(3) .
In addition, the calculating methods of the values of α and β could be adjusted according to the different inclines for disjoint of the links or disjoint of nodes during the process of path selecting. For example, if increasing α, the algorithm tends to find link-disjoint paths, while increasing β, the algorithm tends to find node-disjoint paths. 3.3
Route Recovering
LT-PMPRA uses source-routing method to transmit data, which means multiple paths obtained by it will be stored in header of packets at the beginning of data transmitting, and the intermediate nodes of the path needn’t calculate the path again, which will not only improve the efficiency of data transmission, but also take the advantages of parallel multi-path algorithm. However, for there are some delays in the transmitting of TC messages, and dynamic changes will take place in network at any time, the link state information used by the nodes to calculate multiple paths are not usually consistent with the current actual network condition When there is a link or node failure in the network at any time, it will make the obtained paths unavailable in transmitting process, so the route recovering must be realized in the algorithm.
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Route recovering of the algorithm is achieved by recalculating route nearby the failure paths or nodes, and the specific process as follows: When each node receives a data packet and get the transmitting path information from the header of packet, it will check whether the next-hop node and the corresponding link in the path are included in the current link set and neighbor set of it, if the next-hop node is its neighbor and the corresponding link is valid, then forwards data along the link, otherwise, it means that the next-hop node or corresponding link is not available, so the node will take itself as the source node and recalculate the path to the destination node, and then forward data packets through the new path. For the information stored in neighbor set and link set of the node are gotten real-time by the HELLO message in the local network, so it can reflects the up-to-date local link situation better than the source node which got the information of network situations by TC messages. By adding the route recovering, the routing algorithm proposed improves the reliability and success rate of packet transmission more effectively.
4
Simulation Results
To verify the validity of LT-PMPRA, two types of simulating experiments have been done. The first type of experiments uses the Network Simulator version2 (NS2)[10] to simulate a network with scope of 1000 m×1000 m and 100 hosts in it, in which two kinds of algorithm performance such as the successful rate of data package transmission and the loads of the routers between the LT-PMPRA and the OLSR are compared. The results of the simulation experiments are shown in figure 1 and figure 2 separately.
Fig. 1. Comparison of successful rate of data transmission between LT-PMPRA and OLSR
The figure 1 shows the changing trends of successful rate of data package transmitting according to the moving speed of nodes in the network with 50 CBR data
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sources. It shows that the LT-PMPRA is about 10% higher than the OLSR for it has considered the power factors of nodes into the process of paths selecting.
Fig. 2. Comparison of loads of routing between LT-PMPRA and OLSR
It can be seen from the figure 2, the processes of route finding and route recovering in the LT-PMPRA are much less than those of the OLSR. The reason is that the LTPMPRA use the multi-path routing algorithm based on iterative factors to avoid the failure route by decreasing the intersecting rate of paths on unusable nodes or links, and reduce the number of packets in the network rapidly at the same time, which is very helpful to reduce the routing load of the nodes. So the loads of LT-PMPRA are lower than the OLSR obviously. The other type of simulation experiments is to test the superposition paths in LTPMPRA. In the simulation network environment constructed above, we test the algorithm in the case of the number of the paths found are 3,5,8,10,13 respectively. The choice result of routing is shown in table 1, in which 30 times of tests are done in every path number to calculate the average performance of the algorithm. Table 1. Simulation results Number of paths
Average lengths of paths
Average living time of paths (Units: ms)
Average number of jointed nodes
Average number of jointed links
Average number of route recovering
3
14
90
2
1
0
5
17
85
3
2
0
8
18
60
4
2
2
10
20
54
5
4
3
13
26
39
7
5
6
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From the table 1 we can see that with the increasing of the number of the parallel paths selected, the average length of path, the number of intersection nodes and links will increase accordingly. It shows that the paths obtained cannot avoid completely to be intersected on some nodes and links, but the number of intersected nodes and links don’t become very large with the increasing of number of paths found. On the other hand, the number of route recovering is becoming smaller, which shows the algorithm can avoid to choose the links and nodes that are going to be invalid by considering of the living time of nodes and links. Thereby, it can decrease the number of path calculating and increase the stability of path chosen. In the meantime, the living time of a complete path from source to destination should be the shortest living time of the link included in the path. The results of simulation experiment shows that though the average path living time from a source node to a destination node will decrease with the increasing of the number of paths obtained, the transmitting advantages of the paths will be more obvious if these paths can be used in parallel.
5
Summary
A parallel multi-path routing algorithm is proposed in the paper, which is based on the improved link state algorithm and enhances the stability of the paths selected by some methods such as considering the living time of links and nodes in the processes of path selecting, and using source-routing method to reduce the calculating costs of intermediate nodes of the paths, and increasing the disjointedness of paths by adopting iterative factors in path selecting. The simulation experiments have shown that the algorithm can improve the stability of the chosen paths effectively and enhance the parallel transmission capacity of the paths. Analyzing the qualities and performances of chosen paths of the algorithm will be the further works. Acknowledgments. The project is supported by the Guangdong Province Natural Science Funds Program, China (No.10151042001000020), and the Guangdong Province Science and Technology Planning Program, China (No.2009B010800015), and the Fundamental Research Funds for the Central Universities, SCUT, China (No. 2009ZM0057), and the Guangdong Province Production Education and Scientific Study Program, China (No. 2010B090400460).
References 1. Chen, S., Lu, X., Xu, G.: A novel energy-balanced cross-layer multi-path routing algorithm for wireless Ad hoc networks. In: 2nd IEEE International Conference on Advanced Computer Control, pp. 494–497. IEEE Computer Society (2010) 2. Javan, N.T., Soltanali, S., Dareshoorzade, A., Birgani, Y.G.: IZM-DSR: A new zonedisjoint multi-path routing algorithm for mobile ad-hoc networks. In: 3rd European Modelling Symposium on Computer Modelling and Simulation, pp. 511–516. IEEE Press (2009)
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3. Vijay, S., Sharma, S.C., Gupta, V., Kumar, S.: A new cluster/zone-disjoint multi-path routing algorithm for mobile ad-hoc networks. In: IEEE International Advance Computing Conference, pp. 480–485. Inst. of Elec. and Elec. Eng. Computer Society (2009) 4. An, H.-y., Lu, X.-c.: A Review of Routing Protocols for Mobile Ad Hoc Networks. Computer Engineering & Science, 4–9 (2006) 5. Chen, J.-l., Jiang, T.: An Energy-Aware Multipath Routing Algorithm for Ad hoc Networks. Journal of Electronics & Information Technology 28, 1298–1302 (2006) 6. Vasudevan, S., Kurose, J., Towsley, D.: On neighbor discovery in wireless networks with directional antennas. In: Proceedings of INFOCOM and the 24th Annual Joint Conference of the IEEE Computer and Communications Societies, pp. 2502–2512. IEEE Press (2010) 7. Liang, Z., Lin, J.: Reselinkh of Power Aware Routing Protocol of Ad hoc Network. China New Telecommunications, 18–22 (2010) 8. Chen, S., Wang, L., et al.: A Unicast routing protocol for mobile ad hoc network based on location and power-aware. Computer Applications and Software 26, 216–218 (2009) 9. Clausen, T., Jacquet, P.: Optimized Link State Routing Protocol. Network Working Group Request for Comments (2003) 10. Ke, Z.-h., Deng, D.-j.: NS2 simulation experiments. Electronic Industry Press (2009)
New Method for Intrusion Detection Based on BPNN and Improved GA Optimization Yuesheng Gu, Yanpei Liu, and Hongyu Feng Department of Computer Science, Henan Institute of Science and Technology, 453003 Xinxiang, China {hz34567,feng_hongyu}@126.com, [email protected]
Abstract. It’s very important to detect the network attacks to protect the information security. The intrusion patter identification is a hot topic and using the artificial neural networks (ANN) to provide intelligent intrusion recognition has been received a lot of attentions. However, the intrusion detection rate is often affected by the structure parameters of the ANN. Improper ANN model design may result in a low detection precision. To overcome these problems, a new network intrusion detection approach based on improved genetic algorithm (GA) and BPNN classifiers is proposed in this paper. The improved GA used energy entropy to select individuals to optimize the training procedure of the BPNN, and satisfactory BPNN model with proper structure parameters. The efficiency of the proposed method was evaluated with the practical data. The experiment results show that the proposed approach offers a good intrusion detection rate, and performs better than the standard GA-BPNN method. Keywords: intrusion detection, back propagation neural network, improved genetic algorithm, optimization.
1
Introduction
Network security is a world hot topic in computer security and defense. Intrusion may lead to absence of the internet service and even cripple the whole system for weeks. Hence, it is very important to detect the intrusion in time to prevent broken-downs. Advanced machine learning algorithm, including evolution algorithm, intelligent artificial neural network (ANN) and support vector machine (SVM) and so on, are all appear in the intrusion detection of the networks [1]. Among them, ANN [2] is the most extensive used method. However, ANN detection performance is mainly determined by its structural parameters. It is often difficult to determine the ANN parameters without a large number of trials. Although [3] and [4] using GA to tune the ANN structures to improve the network attack detection accuracy, but without considering the GA individual selection adjustment, and just using the KDD dataset to validate their methods, not for practical applications. Therefore, to improve the GA optimization process and to test the real dataset will have important significance for the ANN based intrusion detection [5-8].
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In order to solve the above problems, this paper proposed a new intrusion detection method. This method has been marked to achieve BPNN parameter optimization using improved GA. By using the practical dataset for experimental analysis, the analysis results show that the proposed new method can detect the network attack efficiently and the detection rates is higher than the standard GA based method. This paper is organized as follows. In Section 2, the proposed intelligent method for network intrusion detection based on the combination of GA and BPNN is described. The application of the proposed method is presented for network intrusion detection in Section 3. The effectiveness of the proposed method is valued by analyzing the real data. Conclusions are drawn in Section 4.
2
New Intelligent Model
Due to the interference of inside and external excitations, the network intrusion is a kind of typical non-stationary signal. The different signal components of short-term traffic flow exhibits various characteristics, and make a difference between the normal and intrusions. One of the most important procedures in the network intrusion detection is to find out distinguished features to differentiate the intrusion cases from the large amount date sets. However, it is always difficult in choosing an effective feature. Fortunately, ANN is an intelligent approach to deal with non-stationary signal. With its strong learning ability, the ANN is quite suitable for practical intrusion detection. However, its identification efficiency depends on the structure design. This is why the GA optimization is applied to the ANN design. By doing so, satisfactory ANN detection model can be gotten, and consequently the detection rate can be improved. 2.1
Improved GA
Standard GA [9] involves the following procedures: coding, selection, crossover, and mutation. In the selection, standard GA only searches individuals with adaptive value. The diversity of the population is constrained, which may lead to premature convergence of the GA optimization [10]. To deal with this situation, the energy entropy based selection is employed to increase the diversity of population. As GA selects according to the individuals' energy, it need to calculate each individual z. The individual energy entropy can be expressed as
E (t ) = In( Where,
1 pt
).
(1)
pt denotes energy probability at lever t. By the annealing selection, we can
derive the individual selection probability [11] P ( zi ) = e
− ( E ( zi )+ β f ( zi ))
/ in=1 e
− ( E ( zi )+ β f ( zi )) .
(2)
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Where, P ( zi ) denotes the probability of individual z in new population, E ( zi ) + β f ( zi ) denotes fitness value of individual z. After the energy entropy based individual selection procedure, the link between individuals is connected and hence to maintain the diversity of population. 2.2
The Back Propagation Neural Network (BPNN)
A neural network has a natural propensity for storing experiential knowledge and making it available for use. One of the most commonly used supervised ANN model is BPNN. The BPNN uses one of the well-known algorithms, back propagation learning algorithm. The structure of BPNN is arranged into different layers: input layer, middle layer and output layer. The workflow of the BPNN can be expressed as follows [12-16]: (1) The input layer propagates a particular input vector’s components to each node in the middle layer. (2) The middle layer nodes compute output values, which become inputs to the nodes of the output layer. (3) The output layer nodes compute the network output for the particular input vector. The forward pass produces an output vector for a given input vector based on the current state of the network weights. Since the network weights are initialized to random values, it is unlikely that reasonable outputs will result before training. Although the weights can be adjusted to reduce the error by propagating the output error backward through the network, the training may suffer from the local minimum. Thus, the improve GA is adopted to optimize the training process to avoid the local minimum. 2.3
The Proposed Detection Model
In this paper the BPNN with improved GA optimization is used for the network intrusion detection. The proposed network intrusion detection processes are given as follows: Step 1: Pre-treat the original network intrusion data to standardized data format. Step 2: Train the BPNN using the PCs, optimize the BPNN structure by improved GA, and determine the network intrusion detection result according to each BPNN model output. Step 3: Test the performance of the proposed network intrusion detection model, and provide the test result as the base for a valid network intrusion management decision. A flow chart of the proposed network intrusion detection method is illustrated in Fig. 1.
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Fig. 1. The network intrusion detection system based on GA-BPNN
3
Experimental Analysis
In order to validate the performance of the proposed algorithm, the intrusion experiments were carried out in real practice application in this paper. The recorded DDoS data describes 30 main attribute of the test network connection, including duration, service type, the bytes issued from source to destination, the bytes from destination to source, etc. In the DDoS detection, 5000 normal samples and 5000 DDoS samples were investigated. The improved GA-BPNN is employed to identify the DDoS. In the GA optimization, the population size is 300, the crossover probability is 0.95, and the mutation probability is 0.01. The GA optimization procedure is illustrated in Fig. 2. In the optimization procedure, the input features of the BPNN select 6 PCs, and the performance of the improved GA has been compared with the standard GA. Form the evolution performance of the improved GA and standard GA, one can note that the improved GA has faster convergence speed and better fitness value, which is benefited from the energy entropy based annealing selection process. 70
60
Improved GA
50
Standard GA Fitness
40
30
20
10
0
0
150
300
450
Optimization iteration
Fig. 2. The performance for BPNN optimization using improved GA and standard GA
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Hence, after the GA optimization, the structures of the BPNN are better than before, and the intrusion detection abilities could be enhanced greatly. This is the advantages of the proposed intrusion detection method against the existing BPNN model. The intrusion detection performance is discussed below. The comparison results of Table 1 show that the Improved GA method for intrusion detection is more effective than the standard GA optimized model. By the improved individual search processing, the local minimum is avoided and the detection rate is enhanced by 2.76%, as well as the detection error is decreased by 0.64%. Table 1. The intrusion detection performance of the improved GA and standard GA model Detection performance Method Detection rate
Detection error
Improved GA-BPNN
94.68%
1.21
Standard GA-BPNN
91.92%
1.85
It can be seen from Table 2 that the GA optimization plays an important role in the intrusion detection based on BPNN model, which can improve system detection efficiency significantly. Compared with FNN method, and the new method increases the detection rate by 7.33%, as well as decreases the detection error by 1.36%. Table 2. The intrusion detection performance of improved GA-BPNN and BPNN model Detection performance Method Detection rate
Detection error
Improved GA-BPNN
94.68%
1.21
BPNN
87.35%
2.57
Hence, from the analysis results in Tables 1-2, it can be seen that the proposed combination of the BPNN and GA algorithm can provide satisfactory intrusion detection performance, and its efficiency is superior to the BPNN model and the BPNN with standard GA optimization. So the proposed intrusion detection method can be used in industrial practice.
4
Conclusions
Intelligent method has been widely used in intrusion detection, especially for the fuzzy logic and ANN. However, reasonable structural parameters of the intelligent
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model play an important role in satisfactory detection performance. Therefore, this paper proposed a new intrusion detection method based on improved GA and BPNN. The innovation is that the new method uses the energy entropy based selection method to ensure the diversity of the generations of the GA, and hence the optimization of the BPNN structure could be enhanced when compared with standard GA. The real practice data was applied to the validation of the proposed approach. The analysis results verify the effectiveness of this method. The intrusion detection rate and false alarm have been improved when compared with standard GA based approaches, and hence the proposed method has application importance. Acknowledgement. This work was supported by the Natural Science Foundation of Henan Educational Committee (2011A520013), Education Reform Project of HIST (2010YB20). And we would like to thank Mr. Li for his good advice for this paper.
References 1. Zhao, X., Jing, R., Gu, M.: Adaptive intrusion detection algorithm based on rough sets. J. Tsinghua Univ. (Sci. & Tech.) 48, 1165–1168 (2008) 2. Li, Z., Yan, X., Yuan, C., Zhao, J., Peng, Z.: Fault detection and diagnosis of the gearbox in marine propulsion system based on bispectrum analysis and artificial neural networks. Journal of Marine Science and Application 10, 17–24 (2011) 3. Xie, Z.: Support vector machines based on genetic algorithm for network intrusion prediction. Journal of Computer Simulation 27, 110–113 (2010) 4. Qiao, L., Peng, X., Ma, Y.: GA-SVM-Based feature subset selection algorithm. Journal of Electronic Measurement and Instrument 20, 1–5 (2006) 5. Xiong, W., Wang, C.: Hybrid feature transformation based on modified particle swarm optimization and support vector machine. Journal of Beijing University of Posts and Telecommunications 32, 24–28 (2009) 6. Li, Z., Yan, X., Yuan, C., Zhao, J., Peng, Z.: The fault diagnosis approach for gears using multidimensional features and intelligent classifier. Noise and Vibration Worldwide 41, 76–86 (2010) 7. Li, Z., Yan, X.: Application of independent component analysis and manifold learning in fault diagnosis for VSC-HVDC systems. Hsi-An Chiao Tung Ta Hsueh 45, 46–51 (2011) 8. Ahn, C.w., Ramakrishna, R.: A genetic algorithm for shortest path routing problem and the sizing of populations. IEEE Transactions on Evolutionary Computation 6, 566–579 (2002) 9. Xiang, F., Zheng, Z.: Research on complex electronic equipment fault location based on improved Genetic Algorithm. In: 2010 International Conference on Computer Engineering and Technology, pp. 1454–1457. IEEE Press, New York (2010) 10. Zhang, Y., Yang, X.: A fast genetie algorithm based on energy-entropy. Systems Engineering Theory and Practice 25, 123–128 (2005) 11. Huang, Z., Yu, Z., Li, Z., Geng, Y.: A fault diagnosis method of rolling bearing through wear particle and vibration analyses. Applied Mechanics and Materials 26, 676–681 (2010) 12. Russell, S., Norvig, P.: Artificial Intelligence: A Modern Approach. Prentice Hall, Upper Saddle River (2003) 13. Kohonen, T.: Self-Organizing Maps. Springler, Berlin (1997)
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14. Lee, S.-Y., Low, W.L., Wong, P.Y.: Learning Fingerprints for a Database Intrusion Detection System. In: Gollmann, D., Karjoth, G., Waidner, M. (eds.) ESORICS 2002. LNCS, vol. 2502, pp. 264–280. Springer, Heidelberg (2002) 15. Lee, S.C., Heinbuch, D.V.: Training a neural network-based intrusion detector to recognize novel attacks. IEEE Trans. Systems, Man and Cybernetics Part A: Systems and Humans 31, 294–299 (2001) 16. Nong, Y., Vilbert, S., Chen, Q.: Computer intrusion detection through EWMA for auto correlated and uncorrelated data. IEEE Trans. Reliability 52, 75–82 (2003)
Creating Learning Community Based on Computer Network to Developing the Community Education Lingyun Zheng1, Caiyun Zheng1, and Chunyan Li1 1 Tangshan
Radio and TV University, Tangshan, 063000, China College, Hebei United University, Tangshan, China [email protected], {zhengcaiyun2006,licyan0315}@126.com 2 Qinggong
Abstract. This paper elaborates the methods of how to strengthen and improve the learning community construction. The author also points out that the comprehensive development of community education provides a theoretical basis and practical support for the establishment of lifelong education system. Community is the foundation of society, and community education is the foundation of the modern community projects. Creating a learning community is not only the main starting point of the community work but also the cornerstone of a learning society. Keywords: community education, learning community, lifelong education learning organization, learning society.
1
Introduction
Community education in China began in the eighties of the 20th century. With the deepening of reform and opening up policy, community education in our country grew gradually and experienced from narrow to wide coverage, from small to large scale. As a grassroots education campaign, it shows a broad prospect and strong vitality in promoting people’s comprehensive development and building a harmonious society. < State Council the decision on further strengthening the human resources work> emphasized “Accelerate the construction of lifelong education system, and promote the formation of learning society. Establish the concept of lifelong learning for all in the whole society. Encourage people to participate in lifelong learning through various forms and channels and promote the building of learning organization and learning society.” Thus, to create life-long learning community is not only an important part of education but also an important starting point in community work. It has a very important practical significance in promoting the community education and community modernization.
common interest, to develop voluntarily a range of learning, action and reflection opportunities, determined by their personal, social, economic and political needs. (CeVe 1990: 2) Community education has three “alls”: the first “all” refers to the targets. All members of society can be the targets, including young students in school. Second "all" is all the time. Communities are continuing to provide education all the time, throughout a person’s life from his birth to the end. The last "all" means a comprehensive education. The contents of community education is comprehensive, including the knowledge, ability, spiritual, cultural and health education and meeting people’s needs of "learning", "living" and "happy life ". Learning Organization This concept began in the late 80. Combined with practice, learning organization can be understood as people learn in organizations to enhance their capacity continually and organizations achieve sustainable development. Learning organization can be divided into ten types: learning system; learning agents; learning party; learning institutions; learning enterprise; learning community(neighborhood residential streets); learning school; learning social organization; learning village; learning family. Learning Community Learning community bases on the community lifelong education network and the learning organization. It protects the community members’ fundamental learning rights and meets the needs of lifelong learning. It is seen as a powerful staff development and life quality improvement approach and a new community for sustainable development. The basic signs for learning community formation are:1) community members participate in learning voluntarily and self-directed learning is a major way of learning; 2) community treats the members’ rights and needs with full respect and provides the learning opportunity fairly at anytime and anywhere;3) generally create a variety of learning organization;4) organizational units within the community pay attention to the education function and can provide distinctive resources 5) The formation of life-long education network, a harmonized regulatory agencies and community education centers (Base) ;6) community education resources are fully developed; 7) community members improve their capacity;8) quality of life is improved 9) community achieves sustainable development etc.
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The Significance of Learning Community
Learning community is the foundation and support of the lifelong education. Constructing Chinese characteristic lifelong education system is to integrate social learning, culture and education resources and improve the wide coverage, multi-level education training network as well. To establish the target responsibility and long-term operating mechanism, learning community should be combined with the mass spiritual civilization and the harmonious community. As a carrier, learning community should find its position and play its role in lifelong education and learning society system. In brief, lifelong education is one of the theoretical origins of learning community. Lifelong education promotes learning community’s construction and the latter promotes the former’s development.
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Learning community is an important way to establish the harmonious society and promote people’s comprehensive development. People’s comprehensive development is the starting point and foothold of the harmonious society and it is the basic characteristics as well. Community members share learning experiences, brainstorm and solve problems through research, project, residents’ discussion, culture and sports activities, forums, salons and other means to promote social harmony. People expand their capacity and create the results they desire. Learning community is an important part of the new modern community. It is critical for modern community to establish the supporting public services, management, benefit distribution mechanism except for the beautiful environment and interpersonal harmony. The residents truly have the right to information and participation in decision-making. The creation of a learning community provides a platform for online education, digital learning center. The residents study actively, independently for selfworth, which are the core elements and foundation of the development of a new modern community.
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Create Learning Community Effectively with Various Measures
Strengthen the learning community organization mechanism. New born and full of unique vitality, it is impossible for learning community to run and manage in the traditional community model. As the main responsibility, government should coordinate the financial, advocacy, education and civil affairs departments and establish the mechanism to ensure funding of community education. Government should establish the teaching faculty and the human resources and support mechanism according to local condition. Promote the building of community networks (learning base and, course) effectively. Community networks include organization network and information network. The former refers to the cooperative network of institutions, namely community colleges, branch, school, educational institutions, enterprises. It provides the learning base for the residents. The latter refers to community learning platform which enriches curriculum resources, and the online library, digital learning center. The combination of two meets the diverse learning needs of community members. Community members can realize accessible learning--select lifelong learning contents and conduct flexible and independent learning activities at any time and any place. Integrate and share resources within the community. Government bears the responsibility for community education and members learning because they belong to public welfare. Government should encourage departments, businesses, shopping malls, and various types of intermediary organizations to involved in community learning actively and provide professional education, knowledge, resources and personnel security through various channels and forms; the education sector should open maximally the educational resources to the public; community should support and assist schools to promote educational reform and provide the social practice opportunities for
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students; community library, activity room facilities and equipment should be opened to the members to achieve the overall planning and comprehensive management of the various educational resources which provides strong support and resources guarantee for the creation of learning community. Support and guide the creation of various types of learning organization. Organizations are the cells of the modern society. The progressive organization is not only the support for the members to achieve the noble ideals and lofty goals, but also the solid foundation of modern civilization. As the “cells”, organizations play a significant role in promoting learning community. To create the learning organization reasonably and scientifically, first, encourage the residents to make groups according to their interests and hobbies. Second, design and create the learning organization evaluation system. The following is the Shanghai Learning Family Evaluation System (Table 1). Third, update the learning concept. Community staff and leaders can work out reasonable learning objectives and contents to improve organizations and individuals continually. Table 1. Shanghai Learning Family Evaluation System
Indicator 1
Indicator 2
Learning concept Learning concept and atmosphere (25points)
Learning contents and approach(3 8point)
Learning atmosphere
Learning contents
Learning approach
Content 1,family members have aspiration of learning together happily 2,good habits of reading good books 3,there are necessary learning spaces, facilities and materials 4,do not believe and participate in the superstitious activities 5,family members learn more than 1 hour every day 6,learn ethics, civility to strengthen personal integrity 7,learn voluntarily and focus on improving the quality of life 8,attend the family education more than 4 times a year 9,accept various of information education by means of modern media
scores
scores obtained
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Table 1. (Continued)
Learning investment
Learning investment and results(37poi nt)
Learning results
10,participate in training actively to have a colorful amateur life 11,learning investment accounted for more than 3% of the total annual household income 12,each family member has a corresponding expendituron education 13,abide by the law and have the knowledge against pornography, drugs, gambling and fraud 14,family relationship is democratic, equal and supportive 15,respect the old, the weak, the sick, the disabled and the pregnant 16,family members improve significantly
Provide a variety of community cultural and educational activities. From spiritual perspective, learning community needs advanced and unique community culture. In urban areas, community members are provided with multi-level education and training e.g. science and technology, production skill, social life, culture and art. In rural areas, the labor force transfers and is trained as the enrichment experts to increase the ability of competing in the market. Community provides diverse, flexible, healthy activities to enrich residents’ culture life, improve their knowledge and skills, from which the residents achieve their self-wroth and community acquires the residents’ recognition and dependence. Achieve double-harvest through project research. Project test refers to the community practice activities which is planned according to the basic situation and reflects the characteristic of the community. It shows the characteristics and highlights of community education, and it is the breakthrough in the further development of community education. Insisting on the project research and focusing on a number of typical pilot projects are the keys to sustainable development of community education. Project research should be designed, implemented and evaluated in strict accordance with “National Community Education Demonstration Project Evaluation Index System” (Table 2). At the same time, we should pay attention to the summary and strengthen “community practice—theory research—community practice” cycle mode.
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Table 2. National Community Education Demonstration Project Evaluation Index System
Evaluation indicators
1,project value
2,project design
3,project implementation
4,project results
Evaluation criteria 1,project and community education has a close correlation 2,project is designed according to reality and insisting seeking truth from facts 3,project has several innovative aspects 4,process has a timetable and is operational 5,have promotion and demonstration value 6,project design is scientific and rational 7,the goal is clear and novel 8,the contents give prominence to the key points 9,have a special project organizers 10,start work according to the timetable of implementation 11,have process check 12,have records of implementation 13,have detailed data and specified format 14,innovative and distinctive 15,comparison of outcomes and obvious effects total
scores
scores obtained
5 5 8 8 10 4 3 2 3 3 2 3 4 20 20 100
Community education is an important carrier of learning society and lifelong education system. Learning community is an important indicator of deepening the community education, and the cornerstone of learning society with rich content and broad extension. The long-term development of community education and learning community needs government’s promotion, concerted efforts of departments and the joint efforts of community members.
References 1. Ye, Z.: Community Education. Higher Education Press (2009) 2. Chen, N., Zhang, Z.: Community Education Management Theory and Practice. Higher Education Press (2009) 3. Nailin, C., Jiantong, L.: Research on Community Education in the Development of Learning Society. Higher Education Press (2010)
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4. Wang, G.: Masters Interview: 30 years of Community Education in China. Zhejiang Science and Technology Press (2010) 5. Cai, R.: New Vision on Community Education. Zhejiang People’s Publishing House (2006) 6. Information on, http://www.weld.labs.gov.cn 7. Ma, J.: Practical Research on Community Education under Lifelong Education System. Higher Education Press (2011) 8. Hellmich, D.M., Boggs, G.R.: Ethical Leadership in the Community College. Oversea Publishing House (2007) 9. Kim, A.J.: Community Building on the Web: Secret Strategies for Successful Online Communities. Peachpit Press, Berkeley (2000) 10. Zhang, d., Wang, M.: Research on Community Education in China. China Metrology Publishing House (2010)
Security Assessment of Communication Networks for Integrated Substation Automation Systems Huisheng Gao and Xuejiao Dai Department of Electronic and Telecommunication Engineering, North China Electric Power University, Baoding 071003, China {Huisheng Gao,Xuejiao Dai,freezydx}@126.com
Abstract. To assess the security of communication networks for integrated substation automation systems, a systematic approach based on index system is presented. An analysis about the actualities and security risks of the communication network was performed firstly. Then, the index system of security assessment was established according to assessment standards about information security. At the same time, index weights were assigned and formulas to valuate index were proposed. Finally, this assessment approach was used to assess security levels of a real communication network, and its effectiveness was validated. Therefore, a guidance and assessment can be provided to communication networks between the control center and substations through the approach in this paper. Keywords: Integrated Substation Automation Systems, Communication Network Security, Assessment Approach, Index System.
This paper puts forward a method with index system to assess security which targeted on communication networks for ISAS. Actualities of communication networks for ISAS and its security risks was analyzed, then according to security assessment criteria and power system communication standards as [8]-[10], with the guidance of index principles in addition, the index system of security assessment was established. It’s used to assess a real communication networks for ISAS to validating the practical value of this method.
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Communication Networks for ISAS
In order to assess a communication networks for ISAS, the present situation and the security problems should be fully recognized and analyzed to making the assessment process targeted. 2.1
Actualities
Communication networks for ISAS consist of channels between substations and the control center. Security of this communication system should contain physical security, network operation security and information security. Some aspects are shown in the table. Table 1. Existing state of communication network for ISAS Transmission medium Channel type Rate Mainly communication protocols Mode Topology structure
2.2
Optical cable, most kinds are Optical Fiber Composite Overhead Ground Wire (OPGW) and All-dielectric Selfsupporting Optical Cable (ADSS) 2M channel, RS232 channel and analog channel 2M channel: 2M/s; RS232 channel: 1200baut/s; analog channel: 600baut/s CDT and IEC 60870-5-101/104. IEC 61850, however, is not used in the communication between the control center and substations at present. The communication mode between substations and the control center is point-to-point. Link structure of channels is chain type structure, and network topology structure is star structure.
Security Risks
Some risks of communication networks for ISAS in nowadays are described as follow: Firstly, communication protocol is a key factor of operation of communication systems, but these protocols rarely add some security measures so far to protect
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system from errors by chance, communication equipment failure or sabotage. The standardization and making public caused the protocols more vulnerable and more possibility to be attacked [10]. Secondly, SDH optic fiber communication is becoming the main form in electric power communication because of its huge bandwidth and ultra low transmission loss. But there are many shortcomings appeared in real operation, including that any fracture in a long distance transmission will lead to interrupt the communication; most optical cables in outdoor are easily influenced by human and natural disasters; operating in electromagnetic environment, electromagnetic interference hamper ADSS optical cables [11]. Thirdly, in power system dispatching center, 500kV substation and 220kV substation, it dose not allow that a communication interrupt happens from the date of completion, thus the reliability of the power supply is especially important. In resent years, communication circuit interrupting caused by power supply fault accounted for a large proportion, so the security and stability of power supply system affects the normal operation of the communication directly [12]. Fourthly, information transmitted in communication networks for ISAS may be intercepted, stole or cracked without interfere with the normal work of the system which can be called passive attack, and active attack includes unauthorized fake, malicious tampering and repudiation, what makes information damaged. Therefore, data encryption, the authentication and access control should be used to ensure the confidentiality, integrity and availability of information [13]. Besides security problems that mentioned above, those factors about operation situation and maintenance of the communication and network devices, network survivability and transmission delay influence safety and reliability.
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Index System of Security Assessment
Index system should be established scientifically with principles and standards. In the index system, each index has different importance to the goal. When measures index contribution to the target, different weights should be given. And a method to value the index is also needed in an assessment process. 3.1
Index System Principles
The scientific nature of the index system is the basis to ensure the accuracy and rationality of the result of assessment, and whether an assessment activity is scientific is largely depend on whether the used index, standard and method is scientific. The scientific nature of the index system mainly contains 4 aspects as follow: First, index should reflect the characteristics of assessment objects, what’s the basic meaning of index. Second, the concept of index should be correct and meaning should be clear, and as far as possible to avoid or reduce subjective judgment. With the assessment factors
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which are hard to quantify, index should be set using qualitative and quantitative methods. Each index of the index system should be coordinated internal unity, furthermore, the level and structure should be reasonable. Furthermore, the index system should be built around the assessment purpose and reflect assessment objects overall. Can not miss important aspects or biased, otherwise assessment results can not reflect object truly and fully. Finally, correlation between indexes should not strongly, and there should not be too much information covers each other making index connotation overlapped. In practice, it is hard to let index completely irrelevant, because all aspects often are related, and index system is composed of a set of unit index with organic connection, so there should be some inner logic in index. Here, the correlation between the index can be solved by reduce the weight of each index properly. 3.2
Weights Assignment
There is Delphi method, analytic hierarchy process (AHP), annulus comparing assessment method, neighboring comparative method used to get judgment matrices A of index weights, then the judgment matrix A is calculated by using geometric mean method which makes the weights more reasonable, finally, solve the correlation between the index with reducing the index weight respectively. Do geometry average to the row vectors of judgment matrix A and normalize, to make the row vectors become wanted weight vectors. The formula is: 1
n n a ∏ ij j =1 wi = 1 n n n ∏ aij i =1 j =1 In the formula,
(1)
wi is the valuation of weight, aij is an element of matrix A in row i
column j. 3.3
Index System of Assessment
Apart from the guidance of establishing principles and analysis of the existing state, further research work as establish the assessment index system of communication networks for ISAS is done according to the generally accepted standard. The paragraph numbers given in the table represent the ISO 17799 clauses included. And index weights are calculated by using the method as mentioned above.
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Second level index Weight Optical cable management (B1) 0.116 Configuration and maintenance of 0.068 communication power supply (B2) Communication station protection 0.097 (B3) Operation and maintenance of 0.119 equipments (B4) Network Management for network 0.110 operation security security(B5) Protocol security (B6) 0.105 Transmission delay (B7) 0.107 Information Data encryption (B8) 0.068 security Authentication (B9) 0.110 Access control (B10)
During the process of assessment, there are several factors influenced the valuation of each index. The value of index is not linear increase with increasing of the related factors’ value. The largest or the least factor value has the most positive or negative affect to index which described by formula (1) and formula (2) respectively:
Bi means the valuation of index, x j is affective factor to index
assessment, and
Roundl [ ] is a rounding process retaining a decimal. Meaning of
the formula is that n factors’ value differ 1 the influences differ 2 times, and the differences reflect the leading role of the largest or the least factor value.
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Brief Introduction of Index
The paragraph numbers of each index given in Table 2 represent the ISO 17799 clauses included, and details are introduced in corresponding chapters of ISO 17799. Those who need additional explanation or brief introduction are indicated below. Index B6: Protocol security means expect using necessary protocols to provide network functions, security protocols [14] should be taken to protect OSI network hierarchy. According to the requirement of substation communication, IEC 62351 put forward the concrete requirements of protocol security. Because of the known vulnerability, it should use TLS (Transport Layer Security) 1.0 or the higher version take place to SSL (Secure Sockets Layer) 1.0 and 2.0. Index B7: Transmission delay mainly depends on transmission distance, rate and encryption delay. The longest transmission distance without relay of optical cable is about 10km, and a relay station is needed with the transmission distance extended every 50km. Communication networks between the control center and substations is wide-area networks, and the transmission usually needs relay. So rate takes an important role. Encryption also cost time, and different encryption algorithms have different efficiency making the encryption time long or short. 3.6
Assessment Example
A real communication network, which is composed of 2M channels, RS232 channels and analog channels between 110kV level substations and the control center in Tangshan area, was assessed with the index system established above, and got the value of overall security which is 2.81. Differences of each index in three kinds of channels are compared as shown below.
3 2
2M channel RS232 channel analog channel
1 0
B1
B2 B3
B4
B5 B6
B7
B8
B9 B10
Fig. 1. Index value of three kinds of channels
Abscissa is index and ordinate is index value. Three different colors represent the each index security values of three kinds of channels. In general, the security of communication networks for ISAS of Tangshan area is satisfactory, especially in the
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aspects of physical security, because it has taken a high level security measures about management of hardware devices and protection for physical environment. The index values of information security are high, too, which is due to the strong access control, mandatory authentication mechanism and effective encryption of organization. Overall, the security of 2M channel is better than others. To survivability, the standby channel operation rate of RS232 channel and analog channel is not high, what makes the index value of the network structure and self-healing capability lower. CDT communication protocol is used in analog channel, and the security of this protocol is worse because of having no security protocol to protect communication. Most substations are far from the control center and the transmission distance is long, so the transmission needs multiple relay which increased the number of link nodes and the delay time. In spire of taking symmetric key encryption with fast data processing, low transmission rate affect great transmission delay of RS232 channel and analog channel. According to the analysis of the assessment result, the method based on index system established above can find out the disadvantages of communication network security, and it has practical value and guide meaning to security assessment aimed at communication networks for ISAS.
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Conclusion
Communication networks for ISAS are one of the most important parts of power system, and it is meaningful for operating the whole system normally and safely to assess the security. The method with index system targeted on communication network for ISAS is established scientifically, and its rationality and feasibility of this assessment index system is proved by an assessment example. In addition, this method can be used to assess the security of real system. Furthermore, correlation between the indexes is solved by reduce the weight of each index properly in this paper, and fuzzy comprehensive assessment method can be used to direct to fuzziness between indexes in further research. Acknowledgement. Thanks for the support of Guiding Project to Science and Technology Research of Institution of Higher Education Hebei Province (z2010291).
References 1. Brand, K.-P., Lohmann, V., Wimmer, W.: Substation Automation Handbook. Utility Automation Consulting Lohmann (2003) 2. Fenz, S., Ekelhart, A.: Verification, Validation, and Evaluation in Information Security Risk Management. Security & Privacy 9(2), 58–65 (2011) 3. Liu, N., Zhang, J., Duan, B., Liu, W., Hao, Z.: Vulnerability Assessment for Communication System of Network-based Substation Automation System. Automation of Electric Power Systems 32(8), 28–33 (2008) 4. Liu, W., Zhang, L.: Information Security level Assessment of Distribution Automation Based on FAHP and Improved D-S theory. East China Electric Power 38(1), 67–71 (2010)
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5. Tang, M., Zheng, K., Liu, Y., Huang, M.: Research on AHP-based Fiber-optic Transmission network security assessment. Study on Optical Communications 5, 20–22 (2010) 6. Yuan, J., Gao, H., Sun, Y., Shi, L.: Security Evaluation Indicator System for Electric Power Optical-fiber Communication Network. High Voltage Engineering 35(4), 960–964 (2009) 7. Krutz, R.L.: Securing SCADA Systems. Wiley Publishing, Indiana (2006) 8. BS ISO IEC 17799-2005 Information Technology Code of Practice for Information Security Management (2005) 9. DL/T 544 Electric Power Communication Management Procedures (1994) 10. IEC TS 62351-1-2007 Power System Management and Associated Information Exchangedata and Communications Security Part 1: Communication Network and System Security Introduction to Security Issues (2007) 11. Zhao, J., Gao, H.: Reliability Assessment on Optical Fiber Protection Channel. Telecommunication for Electric Power System 28(176), 5–8 (2007) 12. Zhu, F.: Faqiang Zhu: The Uninterrupted Power Supplying System for electric Power Telecommunication. Telecommunication for Electric Power System 11, 33–37 (2002) 13. Shi, K., Chen, T.: Problems on Encrypt Communication in Electronic Power System and Communication Authentication. Proceedings of the CSEE 22(10), 34–38 (2002) 14. Zou, B., Li, C., Jiang, Y.: Research on the Security Architecture of Important Information System under Network Environment. China Safety Science Journal 20(1), 142–148 (2010)
Design and Implementation of Multimedia Online Courseware Based on XML/XSLT and JavaScript Lili Sun, Minyong Shao, and Min Wu Center of Modern Educational Technology, University of Science and Technology of China, Hefei, China, 230026 [email protected], {shaomy,minwu}@ustc.edu.cn
Abstract. In order to solve the problems of post-maintenance and resource-sharing for traditional courseware, as well as extracting information and distribution storing data problems for HTML online courseware, this paper initially proposed a design method of multimedia online courseware based on XML/XSLT and JavaScript using XML technologies. This article firstly introduced its design, architecture and development process; then described in detail the implementation of the online courseware with an example; finally stated the key technologies in the process of development. The courseware is a typical application of online courseware for autonomous learning, and its design idea being used can be a reference to other online curriculum. Keywords: XML, XSLT, JavaScript, Ajax, online courseware, jQuery.
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is to say, HTML tags mark the external characteristics instead of logical structure. Therefore, HTML–based courseware is unable to extract required information[3]. As to the above problems, this article initially proposes a design idea of multimedia online courseware based on XML/XSLT and JavaScript. We firstly store the material of courseware in XML format because of characteristics of data reuse, data transmissions among all sorts of applications, and separation of content from style. Then XSLT technology will transform XML source document into HTML object document supported by browser and JavaScript codes to achieve interaction. Firstly, this paper presents its development process. Secondly, with an example, the paper describes its implementation process and key technologies involved. Finally, we make a conclusion and illustrate its advantages and disadvantages of this approach, so as to provide a design idea and reference to other online curriculum.
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Development Process
To develop multimedia online courseware on the basis of XML/XSLT and JavaScript, we will adopt a design idea for separation of data and program. First of all, the processing of material including text, graphics, audio, video and so on, should be considered. Material refers to learning contents of the courseware for students, which is designed and provided by domain experts in a certain subject. Then we will import material into the professional editor for courseware, converting material into XML documents stored seperatly and being unable to be analyzed by browser. By writing XSL stylesheet, we will convert XML source file into HTML object file with a XSL processor. Obviously, HTML tags can be parsed by browser. Secondly, the courseware interaction is implemented by embedding JavaScript codes in HTML document, and
Fig. 1. Development process of online courseware based on XML/XSLT and JavaScript
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the interface design of courseware is achieved by calling external CSS stylesheet in HTML document. Finally, for the purpose of implementation of data transfer asynchronously between browser and server, we apply Ajax technology in the design. Fig. 1 below shows development process of online courseware based on XML/XSLT and JavaScript.
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Implementation Procedure
To develop a series of network tutorials for a Foreign Language Education Press, the author adopts the above pattern of development procedure. We take the development of Listening & Speaking Online Courseware of College English as an example to expound its implementation process. There are fourteen units in Listening & Speaking Courseware, with per unit composed of four sections: Part A, Part B, Part C, Part D, and each section contains some exercises. Since the unit structure is consistent, and yet learning content is different, the page navigation structure of each unit is the same. We define its menu style in menu.xsl file. After summarizing question types of all the units involved, we define its question type style in item.xsl file. The interaction function codes of all the units involved are saved in main.js file. When the main file of each unit calling menu.xsl file, item.xsl file and main.js file, we implement its unit design. As to this approach, not only the question type extends easily but also code reuse and code modification are convenient. In addition,the position of navigation menu, study contents and functions part are located in partition by setting blocks in main.htm file. Embed codes <script type="text/javascript" src="main.js"> in main.htm file can realize interaction function, embed to express appearance of the courseware. 3.1
XML Data Transformation Using XSLT
Material of the courseware is imported into Courseware Editor, then XML document is generated automatically. Take blank-filling as an example: meetmanager ……..
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Nice to you. He is our sales . …….. assessmentItem Class composed of responseDeclaration Class, informationDeclaration Class and itemBody Class defines a type of exercise. itemBody Class includes several question Class, in which a lot of question types are defined. This case is fill-in-the-blank question. Then, using xsl:template and xsl:apply-templates elements can extend question types easily. Part of the codes is as follows[8] [11]: <xsl:template match="assessmentItem"> <xsl:apply-templates select="itemBody"/> <xsl:template match="itemBody"> <xsl:apply-templates select="question"/> <xsl:template match="question"> <xsl:apply-templates select="textEntryInteraction"/> //blank-filling <xsl:apply-templates select="simpleChoice"/> //single-choice …….. In question Class we can increase any type of exercise appeared in the courseware. We define its style for each type of exercise, which realizing the display of contents on the web. The template definitions for the blank-filling question above is as follows[8] [11]: <xsl:template match="textEntryInteraction"> <xsl:element name="input"> <xsl:attribute name="type">text <xsl:attribute name="size">
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<xsl:value-of select="@expectedLength"/> <xsl:attribute name="id"> <xsl:value-of select="@id"/> Then XSL processor analyses the codes above, generating , which is typical HTML language. It can be parsed by browser and displayed on the web. So do other questions. 3.2 Implement of Interaction Function JavaScript programming is applied in main.js file so that the interaction function can be completed easily. For example, program should make a judgment when students finished blank-filling exercises. The concrete operation is that a function named doCheck() in main.js file will be called, as clicking check button of the page. Judging question types is the first step. If it is a blank-filling question, its code will be executed and the right shows √ while the wrong shows × by comparing input information with the answers. Part of the codes is as follows[8] [9] [10]: Var Keys=new Array; //created answers array; <xsl:for-each select="responseDeclaration"> Key[i]={id:<xsl:value-of select="@id"/>, value:<xsl:apply-templates select="correctResponse" mode="jsonarray"/>}; //contents in answers array; ...... doCheck(type) { if(type = ="input") //blank-filling; { if($("input").getAttribution("id")==Key[i].id|| $.trim($("input")[j].value==Key[i].value) //finding answers and comparing input with standard answers; {$("input")[j].parent().appent("
Answer: Key[i].value
"); } //the right shows √; else {$("input")[j].parent().appent("
Answer:Key[i].value
");} //the wrong shows ×; } else {} }
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The corresponding codes are added in main.js file when involving in other aspects of functions. Codes are omitted. 3.3
Implement of Data Transfer Asynchronously Using Ajax
Ajax, namely Asynchronous JavaScript and XML, is an added middle layer between browser and web server. The Ajax engine allows data to be loaded dynamically, which avoids the problems of slow speed as refreshing pages due to loading repetitive data frequently. As far as data from text words is concerned, we use Ajax to accomplish data transfer asynchronously from web server to browser. When user triggers the button to show a list of words, the Ajax engine requests data to server, then server sends data to the client as receiving the request and making a response. The main code is as follows[7]: $.ajax({url: words.xml, type: "GET", DataType: "xml", timeout: 1000, error: function(){} success:function(){}});
4
//address to word list // request data to server //data type //setting timeout // If failure, start to…. // If success, ….
Key Technologies
Because of extensive listening and speaking practices in this courseware, the problem of media play is involved unavoidably. So its technical difficulty is how to play audio or video on the web. Inserting ActiveX controls in web pages is a solution to audio play. We firstly write an interface function, then the human-computer interaction can be accomplished by calling the methods of ActiveX controls. According to demand analysis, we are asked to design three controls: play control, record control and role-playing control, and the controls realize the corresponding functions by setting buttons, such as clicking the play button to play audio. Among them the role-playing control has a special function of playing as well as recording concurrently. With two options, the control is developed for the role-playing questions, when choosing “A”, students start to speak what A role of the dialogue said and at the same time to be recorded, while the dialogue B is said by computer. As choosing “B”, A role exchanges with B role of the dialogue. It seems to be face-to-face communication between teachers and students. The control code is omitted here. Next, we introduce its application in web pages. Reservation node in main.htm file is and the control is displayed in web pages by the codes of $(.rolePlay).html(""); in main.js file. Click buttons of the control, the plugin calls a method of the control to achieve specific function. As to video play, its solution is to insert Flash files into web pages using swfobject script, that is to say, web pages firstly contain swfobject.js, an open-source file, and
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JavaScript codes are added into DOM, which can embed Flash files. Then Flash player starts to play video. Here, the concrete operation is to involve swfobject.js and a div node in main.htm file, create an object called SWFobject and assign parameters of its attributes. Furthermore, to avoid lacking of Flash player for the client, we download a free Flash player, such as flvplayer.swf, and copy the file to the same directory as video file’s. Play video automatically as program accessing to a Flash file.
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This paper discusses the design and implementation of multimedia online courseware based on XML/XSLT and JavaScript, in which the author brings forward a design method to develop a series of online English tutorials for a Foreign Language Education Press. This courseware has the characteristics of standard data, extensible question types, good interaction, friendly interface and easy to use, so that students can be self-study, but it has also some deficiencies because of no database. It is hard to guarantee data safety as issuing the courseware on Internet, so its design idea can only be a reference and useful enlightenment to other online curriculum.
References 1. Zhu, Q.J.: Preliminary Study on the Design of Multi-media English Netcourse. Journal of Chendu University: Educational Sciences Edition 21(4), 59–61 (2007) 2. Liu, L.: The Research and Application of Display Technology for Online Courseware Based on XML: Dissertation. Huazhong University of Science and Technology, Wuhan, pp. 3–26 (2006) 3. Wang, Z., Chen, X.: The Design of Web Course Wares Based on XML Technology. Journal of Taizhou University 27(6), 10–13 (2005) 4. Huang, Y.: Design of Online Courseware for Autonomous Learning. Modern Educational Technology 18(10), 80–84 (2008) 5. Tsai, S.-c.: Courseware development for semiconductor technology and its Symeon Retalis, Emanuel Skordalakis. “CADMOS: an approach to developing Webbased instructional system”. Computers in Human Behavior 17, 393–407 (2001) 6. Wang, K., Fang, M.: Research and Application of Ajax Technique. Modern Electronics Technique 31(6) (2008) 7. White, C.: American XSLT from entry to master, pp. 58–210. Publishing House of Electronics Industry, BeiJing (2003) 8. Zakas, N.C.: JavaScript Programming. Posts&Telecom Press, Beijing 9. jQuery official website (March 10, 2010-April 5, 2010), http://jquery.com/ 10. XSLT Introduction.[EB/OL], http://www.w3school.com.cn/xsl/xsl_intro.asp
The Delay of In-Network Data Aggregation for 802.15.4-Based Wireless Sensor Networks Xiaoyue Liu1, Lin Zhang1, Zhenyou Zhang2, and Yiwen Liu1 1 2
College of Electric and Engineering, Hebei united university, Tangshan 063009, China College of Information Engineering, Hebei united university, Tangshan 063009, China [email protected], [email protected], [email protected]
Abstract. Wireless sensor networks are an emerging technology for low-cost, unattended monitoring of a wide range of environments. Their importance has been enforced by the recent delivery of the IEEE 802.15.4 standard for the physical and MAC layers and the forthcoming ZigBee standard for the network and application layers. In-network data aggregation is a cross-layer routing technique which is essential for wireless sensor networks with a large number of nodes. Although the technique enhances energy efficiency by reducing packet transmissions, it may require routing-layer waiting time which introduces additional delays in packet delivery. In this paper, we try to find the relationship between energy and delay to achieve scheme facilitates efficient tradeoff. Keywords: wireless sensor networks, in-network data aggregation, energy-delay tradeoff.
The in-network data aggregation inherently incurs an energy-delay tradeoff. In protocols which employ this technique, data is not transmitted immediately after its generation or arrival. Instead, a node waits for more incoming data to increase the degree of aggregation (DOA, the number of sensor data elements aggregated into one packet) for energy saving. The larger the DOA, the less is the number of transmissions and energy consumption. However, waiting for more data increases the delivery delay. By delivery delay, we mean the average delay of data elements from the time they are generated in sensor nodes to the time they reach the sink. Using such hardware as a basis for development, the software architecture and communication stack residing on these devices are built taking into consideration the prolific researchin the areas of ad-hoc networking, data aggregation, cluster formation, distributedservices, group formation, channel contention, and power conservation]. Work targeted to these devices include research in query processing (e.g. TinyDB), and aggregation (e.g. TAG).In this paper, we try to discuss condition the energy-delay tradeoff.
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System Model and Problem Definition
2.1
Energy Consumption Model
The energy consumption of each sensor node consists of three components: sensing energy, communication energy and data processing energy. Sensing and data processing require much less energy than communication, so we consider communication energy consumption and data-fusion. We use the same energy consumption model as Heinzelman used for wireless communication hardware [5]. If the node transmits an l-bit packet over distance d, the energy consumption of the node is the energy consumption of the node is
ETx (l , d ) = lE elec + lε amp d 2
(1)
Energy consumption of n-k bits of data-fusion
Eda− fu (k, n) = Efunk
(2)
Where Eelec denotes the energy 1-bit consumed by the transmitter electronics. ε amp denotes the energy dissipated in the transmission amplifier and a represents the path loss exponent. The value of a is 2 for a free space channel model and 4 for a multi-path fading channel model. When receiving an l-bit packet, the energy consumption is
E Rx ( l ) = lE 2.2
elec
(3)
Optimal Transmission Distance
In wireless sensor networks, the energy consumption of each source node sending data to the BS is associated with transmission hops and transmission distance. If we can find the optimal transmission distance and hops, the energy consumption will be reduced to a minimum, so that the data transmission path is energy efficient.
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Table 1. RF characteristics Operation
Energy Distribution
Transmitter Electronics E Tx − elec
50nJ/bit
Receiver Electronics E Rx − elec
50nJbit
Transmit Amplifiers
ε amp
100pJ/bit
Consumption of data-fusion E da − fu
5nJ/bit/message
Let the distance from the source node to the BS be D and let the source node transmit an l-bit packet to the BS through n hops. The distance of the i th hop is di, so that the total energy consumption for transmission from the source node to the BS is n
E = E Tx ( l , d 1 ) + E Rx ( l ) + E Tx ( l , d i ) = i= 2
2 ( 2 n − 1 ) lE
elec
+ lε
n
amp
i =1
n
d i4 , d i =D
(4)
i =1
When d1 = d2 = … = dn = D/n the expression, i =1 d i will have a minimal value and the total energy consumption E is then equal to n
4
E ( n ) = ( 2 n − 1 ) lE elec + l ε amp D 4 / n 4 = 0
(5)
' Eq.(4)will achieve a minimum when E ( n ) =0 or
E ' ( n ) = 2 lE elec − 3 l ε amp D 4 / n 4 = 0
(6)
with the optimal number of hops: nopt=D 4 3ε amp /( 2 E elec )
(7)
then, we obtain the corresponding optimal transmission distance : dopt=D/nopt= 4 2 E elec /( 3 ε amp )
(8)
If the distance of each hop is precisely equal to the optimal transmission distance, the total energy consumption for data transmission will be reduced to a minimum and the routing path is energy efficient. In fact, the optimal transmission distance is hard to set. 2.3
Time Consumption Model
In the media access layer, we use ALOHA protocol [6] as a benchmark, without considering the delay of routing path selection. we establish the time consumption model in the condition of the most optimal path. The different between IEEE802.
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Fig. 1. Success Transmission process of slotted ALOHA
11DCF and ALOHA is that ALOHA has no RTS / CTS handshake, Fig.1 shows the success process that a data pocket success access to channel. The time spend on the process of successful transmitting a packet :we establish the time consumption model based on the result [7]. Wireless communication module of Sensor nodes has 4 possible states: sending state, receiving state, idle state and sleep state. The average time spend on each stage is ttx, trx, tir, tsl. Equation of time slot as following : PHY + L + ACK t s = SIFS + DIFS + R t sl = 0 PHY + L = tc t e = EIFS + R t tx = p s (t s − SIFS − DIFS ) + p e (t e − EIFS ) + p c (t c − EIFS ) t r x = p s (t s − SIFS − DIFS )
(9)
R is transmission rate, PHY is a PHY header, the PHY header in each packet length; L is the length of each packet. 2.4
AIDA Savings Analysis
The cost of packet transmission in the simple single sender, single receiver scenario with no channel contention and an arbitrary MAC layer is the time consumed by the MAC acquiring and setting up eachtran smission plus the time for sending the message, all multiplied by the number of individual transmissions. To maintain MAC layer independence, we simply assign the variable M, to the time (in m sec) for performing MAC layer transmission preparation. For an 802.11 like MAC, this cost includes the channel sense, RTS, CTS, ACK, and intermittent wait times between control packets. For network units of size S transmitted at R bytes/second, the AIDA header overhead is O (in bytes), and DOA is the number of packets aggregated. The cost CAIDA (in m sec) can be calculated from equation (8): CAIDA = M + (S * DOA+ O) * R
(10)
In contrast, the cost of sending DOA number of packets without the aggregation scheme CNone is
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C None = ( M + S * R ) * DOA
(11)
Hence, the percentage saving in cost is calculated as following: SavingPercentage=( C None − C
AIDA
C None
)= 1 −
S *R M + O*R 1 − * M + S * R M + S * R DOA
(12)
Figure 12 demonstrates theoretical time savings as a percentage of the total time it would take to send the number of packets without AIDA. These savings are calculated by comparing the time to send a single AIDA aggregate, consisting of [DOA] network units with one MAC header, versus the time to send [DOA] separate packets without any AIDA header information or data aggregation performed. From equation 10, we can see that the saving increases as the DOA increases when the cost at the MAC layer (M) is non-negligible. To demonstrate the utility of AIDA, we graph theoretical savings for our scheme under an 802.11 like MAC contention scheme for a 200 Kbps channel. The AIDA payload is passed down to a simplified 802.11 MAC that performs idle listening, RTS/CTS handshaking, and follows up each DATA packet with an acknowledgment. The control packet size for our theoretical MAC is 11 bytes. Contention also includes 5 msec’s of idle listening and the DIFS and SIFS intervals are chosen at 10 and 5 msec’s respectively in accordance with the current MICA specifications. We graph variable size network units to better understand the effect of packet size on potential savings[8].
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Performance Results
3.1
The Simulation of Time Model
In order to simulate the data model, value of parameters on the following Table 2. Parameter meters Parameter
value
Parameter
PHY head/b
192
MAC head/b
/ s
20
DIFS/ s
m
5
Received power/W
EIFS/ s
30
SNR threshold /dB
6
value 224
Parameter
value
ACK/b
112
SIFS/ s
10
0.9
Idle power /W
0.74
RTS/b
160
CTS/b
112
noise power/dB
-30
Dormancy power/W
0.047
50
The size of the average channel gain is taken as a constant-15dB, the average waiting time of integration is 3ms. In the MATLAB environment, the simulation results are as follows.
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Fig. 2. Channel saturation θ = 0, delay of different the sensor nodes’ network
Fig. 3. Channel saturation θ = 9, delay of different the sensor nodes’ network
In this paper, AIDA performs lossless aggregation by concatenating network units into larger payloads that are sent to the MAC layer for transmission. Due to the highly dynamic and unpredictable nature of wireless communication in sensor networks, a novel feedback-based scheduling scheme is proposed to dynamically adapt to changing traffic patterns and congestion levels. 3.2
AIDA Theoretical Savings
Figure 4 demonstrates theoretical time savings as a percentage of the total time it would take to send the number of packets without AIDA. These savings are calculated by comparing the time to send a single AIDA aggregate, consisting of [DOA] network units with one MAC header, versus the time to send [DOA] separate packets without any AIDA header information or data aggregation performed. From this chart we can see that as the degree of aggregation increases, the percentage of savings in time increases drastically. We also note that as payload size increases, the relative time saving decreases. This occurs when data transmission time becomes a larger percentage of the total transmission time. Finally, we note that when AIDA fails to perform any aggregation as shown in Figure 4 when DOA = 1, the cost incurred is a single byte of data, which amounts to virtually no increase in transmission time.
Fig. 4. AIDA Theoretical Savings
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Now we compare the performance of the proposed scheme to the conventional schemes. Prior timeout control schemes have various performance targets such as minimizing delay[8,9]and reducing MAC collision[10].They focus on the methods to determine the optimal(or near-optimal)timeout points for such purposes. However, they have showed little interest in how to enforce the timeout itself. Most prior schemes enforce timeout with one of the two simple methods: (1) changing the temporal limit of waiting time, and (2) changing the target DOA. Note that, in both schemes, the timeout is not changed dynamically according to the amount of currently accumulated data. We compare these two conventional trade off methods to our solution, DMU 2.
Fig. 5. The trade off efficiency of our proposed scheme(DMU 2) is compared with conventional tradeoff methods
Fig.5 shows the tradeoff efficiency of the three methods. The graph plots the delay incurred in achieving a certain level of energy efficiency in terms of 1/DOA. This graph can also be considered as plotting the energy consumption to achieve a certain level of delay requirement. From either point of view, the nearer the curve to the axis, the more efficient is the tradeoff. The DMU 2 shows better performance than the two conventional schemes; that is, high energy efficiency can be achieved with little overhead in delay, and vice versa. Fig.5 (a) and (c) show the tradeoff efficiency in cases of w and high incoming DOA, respectively. It is clear that DMU 2 performs better than the conventional schemes despite of the uneven incoming DOA. Note that the amount of performance enhancement is slightly reduced when the incoming DOA is uneven. Because our scheme is primarily designed for the even incoming DOA, it is in conclusive whether the performance results in Fig.5 (a) and (c) is the achievable maximum or not. We can imagine a timeout control which considers the distribution of incoming DOA. We leave this as a future work because the issue of incoming DOA needs to be investigated systemically considering some important factors such as a node’s position in the network and the multi-hop behavior of nodes. For an example of the multi-hop behavior, if a node increases timeout, its outgoing DOA and, thus, the incoming DOA of its upstream node will increase.
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Conclusion
In this paper, AIDA performs lossless aggregation by concatenating network units into larger payloads that are sent to the MAC layer for transmission. Due to the highly dynamic and unpredictable nature of wireless communication in sensor networks, a novel feedback-based scheduling scheme is proposed to dynamically adapt to changing traffic patterns and congestion levels. we know through the DOA can effectively reduce the energy consumption of the WSN and improve the working life; but time delay of the network will increase, Particularly when Scale of WSN is large. Therefore, in high demanding of real-time WSN, we should mention relationship of the expense of the energy network and timing. The objectives of real-time and low power consumption cannot be both achieved by in-network data aggregation. We know through the DOA can effectively reduce the energy consumption of the WSN and improve the working life; but time delay of the network will increase, Particularly when Scale of WSN is large. Therefore, in high demanding of real-time WSN, we should mention relationship of the expense of the energy network and timing. The objectives of real-time and low power consumption cannot be both achieved by in-network data aggregation.
References 1. Akyildiz, I.F., Su, W., Sankarasubramaniam, Y., Cayirci, E.: Wireless sensor networks: a survey. Computer Networks 38(4), 393–422 (2002) 2. Intanagonwiwat, C., Govindan, R., Estrin, D.: Directed diffusion: a scalable and robust communication paradigm for sensor networks. In: Proc. of MobiCom 2000, pp. 56–67 (2000) 3. Krishnamachari, B., Estrin, D., Wicker, S.: The impact of data aggregation in wireless sensor networks. In: Proc. of DEBS (2002) 4. Heidemann, J., Silva, F., Intanagonwiwat, C., Govindan, R., Estrin, D., Ganesan, D.: Building efficient wireless sensor networks with low-level naming. In: Heidemann, J., Silva, F., Intanagonwiwat, C., Govindan, R., Estrin, D., Ganesan, D. (eds.) Proc. of OSP (2001) 5. Heinzelman, W.: Application-specific protocol architectures for wireless networks [Ph.D. dissertation]. Cambridge: Massachusetts Institute of Technology (2000) 6. Wang, C.-j., Geng, F.-p., Liu, Y.-a., et al.: A novel random access protocol for Ad hoc wireless LANs. Acta Electronica Sinica 33(1), 26–31 (2005) 7. Yang, W.-d., Ma, J.-f., Pei, Q.-q.: Performance analysis and optimization for IEEE 802. 11 DCF in finite load. Acta Electronica Sinica 36(5), 948–952 (2008) 8. He, T., Blum, B.M., Stankovic, J.A., Abdelzaher, T.F.: AIDA:adaptive application independent data aggregation in wireless sensor networks. ACM Transactions on Embedded Computing and Systems (TECS) 3(2), 426–457 (2004) 9. Lu, X., Spear, M., Levitt, K., Matloff, N., Wu, S.F.: Using soft-line recursive response to improve query aggregation in wireless sensor networks. In: Proc. IEEE International Conference on Communications (ICC), Beijing, China, pp. 2309–2316 (May 2008) 10. Li, H., Yu, H., Yang, B., Liu, A.: Timing control for delay-constrained data aggregation in wireless sensor networks. International Journal of Communication Systems 20, 857–887 (2007)
About the Thinking of the Influence of Internet to the University Students Naisheng Wang Department of the humanities, Shandong Traffic and Transport, University, Jinan, 250023, China
Abstract. At present, the internet has brought lots of Influence to many aspects of social life, especially to the young university student's ideas, concepts and behaviors particularly broadly and profoundly, and the influences are the impact, both positive and negative. Therefore, at the ages of the network times, we must strengthen and improve moral education in the universities, we will focus on strengthening socialist belief education and the network Psychological Health Education, on the other hand, we must strengthen leadership to keep the network advantages and try to develop the information resources, and then establish the network security systems and a contingent of troops whose job is ideological and political work. Keywords: internet, university students, the impact, moral.
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Introduction
The computer information network is not just the tools to promote the human progress but also a kind of the cultural carrier. It is continually passing on the people varies of cultural information. China internet information has made great progress since the opening up to all-round society in 1995. It quickly and clearly affected the generation of the concepts and norms of behavior, especially to the young people. In our internet users, three are 88.4 percent persons between the ages of 21 and 35 and among them more than 88.4 86% persons received their college education. Thus, the mass internet users in China are the young students, especially the university students. However, the internet is an open, it has a great deal of information, including a large number of diverse advanced, healthy, and useful information as well as a lot of contents of the reaction, superstition and smutty. We should attach importance to the information and research on the internet for young students ideological and moral, it not only concerns the development of the network health but also concerns the health of the youths’ bodies and souls at the age of information.
and perspectives. At the same time, the internet will have an information society, a virtual school, virtual libraries, internet shopping, remote and medical new things, thereby not only a fundamental change in the existing industrial structure and work in the structure and consumption structure and it will be greatly changing the people's lives, communication and ways of thinking, The values and ethic of profound changes. At the same time, we shall see, the internet in human society facilitate effective and meanwhile it has the potential and actual negative effects such as the network security and criminal issues, causing the pollution and entrench divisions and smutty.
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The Influence of Internet to the University Students
3.1
The Positive Influence of Internet to University Students
The Internet Lays Out New Space for the Development of Ethical Awareness. In the internet age, the knowledge of delivery will be faster and accelerate the growth of knowledge, meanwhile, the application of knowledge and the innovation of knowledge are both moving faster. The internet provides the teachers and students are a lot of things and the library, it can leave school, the family, government agencies, research institutions and enterprises to be got together, it can transfer abundant multimedia messages,and make the users acquire knowledge no longer restricted by a space and time. On the other hand, the internet provided with a wide range of interpersonal or social concern and practical integration of a new kind of "reciprocity" education. The network space technology for interactive teaching, students can play the initiative of learning, the teachers and students to communicate more convenient; The use of electronic online exchanges place bbs, between teachers and students and students can explore. The above circumstances indicate that the information society, through the internet will make students really not to go out to know the events happened outside and make friends all over the world. The new network environments creating a wider awareness on ideas and values, moral values and way of life for a wide an influence, can inspire the university students active cooperation and solidarity, and it can also stimulate their trailblazing and creativity. The Network Society Is another Survival Space Opened to Human but the New Information World Basically are Not Laws, the Net of Moral Standard Is Not Mandatory, Only Personal Conviction Is to Hold on the Internet Moral Conduct. It sets higher demands for a high moral consciousness of self-discipline and selfdiscipline, The tighter control your behavior. The network technology development has already promoted the way of the interaction between people. The Internet possesses its existential virtual nature and makes cyber culture show a recessive subject character .It needs people the high mental and moral reliability and the wards. The network development and human experience, this respect to human pursuit of truth and having put in practice and seek truth from facts and moral requirement, on the other hand, the network increasingly becomes the spirit of the collective strength, it wants people to be more positive spirit and harmony with others.
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The Internet can Guide and Promote the Success of the University Students Themselves. On the one hand, the development of the internet is expanding the young students of practice, enhances their understanding and the ability for creativity into full play to the user. It can provide energy and help enhance the youth netizens confidence, broaden their understanding of vision and stimulate their imagination, creativity and knowledge and promote large the students the standard of the continual promotion of psychological development. On the other side, the internet is a fundamental, an opportunity for the redistribution of ideas and once again, knowledge and wisdom and value of standing in full. Bill Gates in computers and networks have a big success. Sohu’s Zhang Chaoyang and Yahoo's Yang Zhiyuan the heroes to the internet, are symbols of the success to the young students. It provides an example and demonstration, large young man are working hard and are motivated to explore the pursuits of their own. 3.2
The Negative Influence of Internet to the University Students
Impressionably Influenced by the Western Ideology of Erosion. The internet, on behalf of the world integration and modernization, it is a huge information resource database, but it is all not advanced and healthy. The network users, without the power of acute observation and accurate judgment, might adversely get the pollution and the university students, observation and judgment are relatively weak, in some without filter ideas, views and false, the reactionary, pornographic information such as direct radiation, they tend to be lost. In the long, students are exposed to the west of the social life style and ideological and cultural attitudes towards appreciation to the capitalist private ownership and the values of erosion. The Network the Crime Explosion Brings Credit Crunch. Human society has entered into a network, life in the digital space. the development of the internet on the one hand to people's study, life is wrong, on the other hand, offer a convenient, some people use commercial secrets, the computer network steal data or other bank accounts, the users of privacy, the computer viruses and malicious attacks network, the public network, has not taken is unknown. The internet brings credit crunch is an open secret. The internet environment, especially to the young students netizens is extremely harmful, and they live in the cheating Cyber space, it is bound to be harmful to set up their correct world outlook and they will be doubtful about the society and also doubtful to find a reliable man. The Network Leads the Estrangement of Human Feelings of and the Variation of Associate Psychology. Human emotion is need of sustained social interaction. While in online exchange, we all have been converted into binary, we have to figure a way of life on the screen, changing the spread of social exchange in the way of communication and the communication changes into between men and machines. If the university students get along with the computer, for a long time and a reduction of social contact with the spoken language ,they will have the attachment and excessive dependence on the information world and the computer, this kind of situation can easily lead them to ignore the true social relationships, which is not good to have
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interpersonal relationships, apathy and alienation, and gradually changes their family and social values, and it even leads to serious psychological perversion. The Anonymous Act on the Internet Leads to the Dissonance of the University Students’ Cognition. According to the social studies, the anonymous cases, people are more likely to make the sexual behavior, there is a responsibility for the people dispersed effect. The main reason is that the internet does not require any person out of his true identity, the internet users can give up any name., and the multimedia the world also provides rich variety of masks, the users can freely choose to be used as status symbol. The anonymous condition, the people who have a feeling of oppression and fancy-free, enjoying a chance to show themselves. It is precisely this opportunity leading to many young students dazed perplexed. They can not feel what kind of a man they are, which is in a quandary and loneliness, in conduct they will be abhorrent. The Netizens are Easily Suffering from the “Internet Addiction”. Scientific research shows that human nature to exist in the game, and the crowd in a particular probability distributions have some, including computer or the internet on a probability distributions. Besides, computer and internet games are really rich, and the novels have magnified the youth of curiosity and exploration, many people can't control themselves. In addition, exchange and sex, violence, vulgarization of audiovisual abundant, and the kinds of information lead the youngsters indulge in a network, keeping a distance from the social reality.
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At the Network the Age the Universities Need Efforts to Strengthen and Improve Moral Education
The institutions task is to cultivate socialist modernization of able constructors and successors in the face of international information on the internet. The high new information technologies in talk-education to the new task, we should endeavor to strengthen and improve their moral education institutions in developing students become the internet users at the same time, we should improve the ideological and ethical standards, directing them correct the network. The importance of psychological education network, and lead them to look at the right to social development of positive and negative effect, and we must strengthen leadership, and try to keep the development of information resources, networking security system and a contingent of troops whose job is ideological and political work . 4.1
Strengthening the College Education of the Socialist Beliefs
The ideological and moral education will continue to use the main routes to educate the students to grasp the true meaning of Marxism and Mao Zedong thoughts and Deng Xiaoping theory, and the proletarian world outlook, outlook on life and values and traditional Chinese culture and education, help students understand Chinese culture and knowledge of socialist construction, stimulate students' patriotic enthusiasm and increase their pride and self-confidence of socialist china; to improve political discrimination between right and wrong.
About the Thinking of the Influence of Internet to the University Students
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Educating and Leading the University Students to Set up the Correct Web Moralities
The university students generally value to learn and use the technology, they are attracted by the rich information and freedom of the associate form on the net, but they have little knowledge about "internet moral vacuum" and "network affection of human lives." This requires a higher political and ideological workers have to help students increased to socialist moral standards of the cognitive ability to guide students set the correct web morality, to raise them to observe the rules of the legal system of network and enhanced their own resisting force, and cultivate their civilization and culture. the net, the moral self-discipline and homemade ability to help them enhance information network of consciousness, the social morals and ethics into its own network the code of conduct and make proper use of network ,so as that the university students will not do harm to others and the society. 4.3
Doing Efforts to Raise the University Students’ Abilities to Process Information, Select and Use of Information
The Internet is rich in contents, including the news, the latest technology, but there are also "junk" on the internet particularly there are some harmful things like smutty, not health information and the low tastes of the online games, these things will not only cost a lot of time, they also affect the students’ healthy growth. The moral education task is to educate and to guide and inspire the students to computers and internet in their study and work in church their own network information resources discrimination the ability to help the students learn how to use the information and assessment of all kinds of information on the meaning and value, self-awareness, and learn how to use of resources to develop their own. 4.4
Maintain the Internet’s Advantages and Sing High the Theme of the Society Advocated on the Net
The Colleges should make full use of network fast, vivid, easier and more open and the potential to develop and promote ideological and political education resources for information and online information and participate in discussion, and networks. First, we should actively develop political and ideological teaching software, and the contents should use the software, Marxism's basic position and views and thinking methods to make electric teaching materials which should reflects the hot, difficult questions concerned most by the students .Secondly, We should opened web pages about the ideological and political work on the Internet to propagandize such kinds of themes as news and current affairs , economic and social, environmental and development ,quality education, loving action and so on. Moreover, we should concern about online information and take part in online discussions. All of these can help to know directly of the students’ thinking and get firsthand data. On the other hand, an educator can directly show his views and attitudes to the students, and their ideas will be easier for acceptance.
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Paying More Attention to the Psychological Education about the Network
The young university students are in a mental to mature but they are not in mature time yet, they are easily troubled and influenced by the network information which are always varied and complicated, and all of these usually lead their mental disorders. Therefore, the institutions should be active to face the challenge brought by the internet and paying more attention on the psychological education about the network. On one side, the university education network, should make good use of network development of space and mental health education opportunities and network resources, to expand higher education and health coverage, and make them more influential; On the other hand, the university authorities should be careful to study the youth internet users of the dynamic and changing, and inspire and guide students voluntary acceptance of help and services. Through effective health education, students can know the correct view of the internet network and the gap between the world and the real world, and properly to deal online with the net relationships, and right attitude towards a virtual space, and the reality of the space to accommodate their mentally, and good attitude in facing the network the world. 4.6
Improving the Systems and Establish the Network Security Systems
Online information and its impact and roles are not all good or healthy to the young students. On one hand the university authorities should establish and improve rules and regulations, improve the network of administrative measures to strengthen the management of a lan, campus net, specify sites the netizens, and network of the main responsibility, rights and obligations, so that the students could know what to do and what is forbidden to do. On other hand, the university authorities should also establish the network security system, as by the establishment of a firewall, digital technology such as authentication and antivirus network security system for the timely and effective supervision and control of information in the selected filter out of date and information to prevent illegal information, information and harassment of information dissemination of information and viruses. 4.7
Strengthen Leadership and the Construction of the Administrators Team
To improve the network the ages of the university's ideological and moral education, the key lies in leadership. The leaders should arrange the management of the network system on the agenda and improve the organizations, responsibility, strengthen supervision and resolved the major problems in the work in time. To establish a team with a high level of political, ideological and political work, and effective control on the internet network technology, political and ideological education of high quality personnel, In order that they can make online exchange with the student and listen carefully to the students and then get what the students are thinking and what they are caring about. It is a good and effective to solve their ideological problems; On the other hand, the state of their minds and what they concerned can be organized and then the suggestion can easily be offered to the university leaders and staff, at last the exchanging bridge can be built between the schools and students.
About the Thinking of the Influence of Internet to the University Students
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The Measures to Train the Ability of the College Students’ Self-education
5.1
The First Second Measure Is That the College Authorities Should Establish Psychological Counseling Agencies to Help the Students Develop the Ability of Self-director
The professional teachers should direct the student s’ life, contacts, education, employment and psychological difficult questions. By helping the students cope with the difficulties, it can promote their subjectivity and cognitive ability, thereby forming the ability of self guidance. At the same time, the dean of students individual forms the self concept of confidence and coordination, contributing to a reasonable selfevaluation. 5.2
The Second Measure Is That the Students Pride Should Be Respected and Protected. It is the Key to Train Students’ Upstanding Mental Quality
One famous educators said that : "Self-education needs a very important and powerful stimulus --- pride and self respect and desire to advance. If the students respect themselves much more, they will accept the moral education given by the teachers more easily. Otherwise, if they are lack of self respect, they will not be willing to accept the teachers’ guidance. So the teachers must respect the students self-esteem, on the contrary, there are not self-education. The educators should constantly stimulate students' desire and motives of self-education to enhance the students’ confidence and to do things better in a future time. 5.3
The Third Measure Is That the Educators Should Help the College Students Improve Their moral, Cognitive and Judgment in Practice, to Enhance Their Analyze Capabilities
The American report of the curriculum development and management association in the 1989 focused on two about cultivating ethical judgment :The first is the moral education is beyond the field of knowledge. That is to say, do not simply tell the students what is good and evil, but let the students to participate in practice, and to evaluate. The second is moral education should care about the training the students’ critical and decision-making ability. American schools lay special emphasis on the development of moral judgment, treating it as university’s central task, and an important indicator of the college to promote ability of adapting to diversification in society and the self-discipline, They commit to moral education scientifically and look for the law of the moral education, and try to turn the Standardized Education into the overall development of the students, and achieve the coherence of the students’ moral cognitive, reasoning ability and mortal practice. Therefore, developing and enhancing the college students’ moral cognitive is an effective way to train the ability of the students’ self-education.
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The Closing
The network has become an essential part of life of the college students, and they are the successors of the contemporary China's socialist spiritual and material civilization construction, and if they can grow up healthily in the ages of network becomes our focus on priority. By our investigation, we can find our network development is on the whole network the ages, but we are thinking of the university students active in a relative of the fast-crumpling, it has become the key for us to guide the new generation of students to be the useful persons in the future. We must strengthen leadership to keep the network advantages and try to develop the information resources, and then establish the network security systems and a contingent of troops whose job is ideological and political work.
References 1. 2. 3. 4.
Xie, H.: The Internet and Ideological and Political Work Overview. Fudan University Press, Shanghai (2000) Chen, Y.: Internet’s Influences on the University Students. Guangzhou University Journal (social sciences edition) 07 (2002) Information on, http://wenku.baidu.com/view/196c0060caaedd 3383c4d3e8.html Information on, http://gfgyjx.blog.163.com/blog/static/59598415 200819114626627/
Design and Implementation of the Image Processing Algorithm Framework for Remote Sensing* Han Ling1,*, Tao Fada2, and Li Minglu3 1
College of Geology Engineering and Geomatics, Changan University, Professor, China 2 College of Ggeology Engineering and Geomatics, Changan University, Graduate Student, China 3 The school of Resource and Earth Science, China University of Mining and Technology, Senior Engineer, China [email protected], [email protected], [email protected]
Abstract. This article made a detailed introduction to the design and implementation of image processing algorithm framework, with its focus on data-driven, image processing algorithm, UI and processing dialog optimization. Implemented by the C++ programming language, the final framework provides a new way and reference to the Customizable development of remote sensing image processing algorithm.The remote sensing image processing system is a set of technologies and methodoloies that can add enormous value in handling the problem of the earth sciences and related fields.Most practitioners are, primarily, professionals in fields such as hydrology, agriculture, engineering, forestry, geology and urban studies; giving them the writing remote sensing processing algorithm skills considerably enhances their expertise and capablities. Keywords: Remote sensing, image processing, remote sensing algorithm, framework design, algorithm implementation.
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Introduction
Remote sensing is an applied discipline, which includes a series of technologies and means, that are of great value in dealing with issues of earth sciences and related fields. Practitioners engaged in hydrography, agriculture, engineering, forestry, geology, environment and urban planning are generally quite professional, so knowledge of remote sensing can greatly improve their professional skills and practical abilities[1]. This thesis targets technical staff who use remote sensing to solve practical problems, provides them a way on how to develop their own remote sensing image processing algorithms, which can be tailored to domain-specific needs. *
Fund: Doctoral Fund of Ministry of Education (A study on the Technology of Remote Sensing Alteration information Extraction 2009025053110004).
Before using the third-party libraries, the user must read open source license, besides the more familiar GPL agreement, there are other ones such as the LGPL license, BSD licenses.Third-party libraries can not be linked to your program or as a part without a thorough understanding of the associated licenses. Boost library is a portable, open source C++ library. Open source isn't just for nerds and researchers. Real world programming challenges, irrespective of whether they are open or closed source, can benefit enormously from the thought and experience that has gone into the Boost software libraries. Put simply, for any given problem for which Boost provides a solution, Boost will strive to provide the best solution possible. It's up to you to decide whether we've achieved that, but as these pages will testify, many other developers have found our solutions to be the best for them[2]. Gdal is a translator library for raster geospatial data formats that is released under an X/MIT style Open Source license by the Open Source Geospatial Foundation. As a library, it presents a single abstract data model to the calling application for all supported formats. It also comes with a variety of useful commandline utilities for data translation and processing[3]. GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS). As such, it aims to contain the complete functionality of JTS in C++. This includes all the OpenGIS Simple Features for SQL spatial predicate functions and spatial operators, as well as specific JTS enhanced topology functions. GEOS is available under the terms of GNU Lesser General Public License (LGPL)[4]. MTL (The Matrix Template Library) is a high-performance generic component library that provides comprehensive linear algebra functionality for a wide variety of matrix formats[5]. Proj.4 is a famous map projection library[6]. TinXML is a simple, compact C++ XML parser which can be easily applied to remote sensing image processing algorithm. VLD is a third-party open source memory leak detector: Visual Leak Detector. 1.2
System Software and Hardware Requirements
Operating system is Windows XP SP2, object-oriented programming language Microsoft Visual C++ 2005, all can run on a common PC.
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System Design
2.1
Data Driver
Data type definition for Image data interface: this class is to redefine certain data types, resampling mode, import and export symbols, also contains some common header information. For example, some commonly used macros: NULL as 0, pi as 3.14159265358979323846, the return value type, the export symbol definitions, unsigned char as 8U data.
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Fig. 1. Overall design of remote sensing processing algorithms framework
Progress bar interface definition: set the progress bar title, set the progress bar prompt, set the total steps, user tooltip. Geographic coordinates, projection coordinates and image row-column conversion: projection coordinates and geographic coordinates conversion, image row and column exchange. Raster data driver Image open, creation, associated attribute information, such as the image open: openraster, image creation: createraster, to obtain information about the number of image bands, image size, etc by opening the image data. Raster data band data management read and write: read raster data, write rastere data to get histogram information. Data block management of raster data, read and write: space allocation for the data block, set data in the block, access to block information, for example, the index of the block, the block size. Data set class definition: Handling of multiple data sources case, open the data set and so on. Vector data driver Vector data open, create, get relevant property of the image, such as data open, geographical coordinates of the data range. 2.2
Image Algorithm
Data conversion: Image data format conversion, vector data format conversion, vector to raster, raster to vector, establish image pyramid, image ECW compression, image ECW decompression Image Interpretation Image enhancement in the spatial domain
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Convolution enhance, non-directional edge enhancement, focusing analysis, texture analysis, adaptive filtering, statistical filtering, sharpen processing. Radiation enhancement Image LUT toning output, LUT stretching, image linear stretching, image piecewise linear stretching, histogram equalization, histogram normalization, histogram specification, logarithmic enhancement, index enhancement, noise processing. Spectral enhancement[7] Principal component analysis, principal component inversion transformation, decorrelation stretching, tasseled cap transformation, color-space conversion, index calculation, natural color transformation, TM radiation coefficient transformation, spectral mixture Frequency transformation[8] Fourier transform, inverse fourier transform, wavelet transform, inverse wavelet transform, frequency domain filtering, homomorphic filtering, periodic noise removal. Terrain analysis Grade analysis, slope analysis, elevation zoning, color relief map, DEM generated contour, visibility analysis, DEM height conversion, three-dimensional relief. GIS analysis Domain analysis, cluster analysis, reject processing, perimeter calculation, locating and analysis, overlaying analysis, matrix analysis, recoding, inductive analysis, regional characteristics. Image fusion[9-10] HIS fusion, weighting fusion, PCA fusion, wavelet fusion[11], pansharping fusion, natural color fusion, HPS image fusion, Ehlers image fusion, Sar image fusion, fusion evaluation system[12]. Image preprocessing Solar elevation angle correction, atmospheric correction, comprehensive correction, thin cloud removal, periodic noise removal, projection definition, the image reprojection, zone dividing of Gauss projection, coordinate transformation, standard framing. Common Image Manipulation Change detection based on spectral type characteristics[13], change detection based on spectral change vector, image binarization, texture analysis, NVDI calculation, band correlation analysis, remove bad lines, data stretching, image reversal, band math, band combine, image cut, image mirroring, image rotation, image resampling, mathematical morphology, channel mixer, vector cuting image. Grid analysis Elevation point generated TIN, generated Thiessen polygon, raster layer classification, grade and slope analysis, DEM distance calculation, DEM area calculation, DEM volume calculation, contour switch to DEM, raster buffer analysis, elevation point generated DEM, DEM generated contour, TIN generated DEM.
Design and Implementation of the Image Processing Algorithm Framework
Remote sensing image processing algorithms usually process image file. A basic UI has to be designed for handling user input and interaction as well as the validity of the parameters, such as band, AOI, sampling method, spatial scope. From this class, more specific ones can be derived, adding more interface elements to meet the special needs of the algorithm.
CDlgBase
CDlgMultiBase CDlgPCA CDlgHISFuse Fig. 2. Dialog class inheritance
Dialog interface design Dialog boxes were organized through the“building blocks”approach; combined with several comon remote sensing algorithm models. To meet the user interaction needs, different models can be combined, dialogs can be created dynamically. Help manual Compared to the general image manipulation, remote sensing image processing is more complex and professional; therefore, a comprehensive documentation is necessary for the user to gain an understanding of the algorithm. All algorithm interface design All remote sensing algorithms are integrated in the Image Processing Toolbox, and there are seven parts in the box. Perfect help documentation is guided the users how to use.
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Fig. 3. Dialog module design
Fig. 4. Image processing toolbox
References 1. Zhang, x., Jin, s., Li, j.: The overall design and realization of GeoImage. Journal of Geomatics 2, 14–18 (2000) 2. GDAL - Geospatial Data Abstraction Library, http://www.gdal.org/ 3. Boost C++ Library, http://www.boost.org/users/uses.html
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4. GEOS - Geometry Engine, Open Source, http://trac.osgeo.org/geos/ 5. The Matrix Template Library 2, http://osl.iu.edu/research/mtl/mtl2.php3 6. PROJ.4 - Cartographic Projections Library, http://trac.osgeo.org/proj/ 7. Babu, K.R., Nevatia, R.: Linear Feature Extraction and Description. Computer Graphics and Image Processing 13, 257–269 (1980) 8. Briham, E.O.: The Fast Frourier Transform. Pretice-Hall, N.J (1978) 9. Li, h.: Research on Multisensor Image Fusion Algorithms, xi’an, China (2006) 10. Liu, x.: Study of Multisensor Image Fusion Algorithms, xi’an, China (2006) 11. Li, S., Yang, B.: Multifocus Image Fusion by Combining Curvelet and Wavelet Transform. Pattern Recongnition Letter 26, 383–387 (2008) 12. Xydeas, C.S., Petrovic, V.S.: In: Objective pixel-level image fusion performance measure. In: Proceedings of SPIE, vol. 4051, pp. 89–98 (2000) 13. Liu, x., Li, w., Gao, l., Tao, f., Ni, j.: Research of Investment Projects Searching Technology Based on Images Change Detection, Beijing, China (2010) 14. Richards, J.A., Xiu, p.: Remote Sensing Digital Image Analysis, 4th edn., Canberram, Australia (2008)
A Multi-Attribute Group Decision Method Based on Triangular Intuitionistic Fuzzy Number Xiaoyun Yue1, Dewen Zou2, Yajun Guo1, and Guosheng Wang1
2
1 Institute of Mathematics and Information Technology Office of scientific research, Hebei Normal University of Science and Technology Qinhuangdao 066004, Hebei Province, China [email protected]
Abstract. This paper proposes a new method of multi-attribute group decision by using triangular intuitionistic fuzzy number (TIFN) to represent the experts’ evaluation information. At first, giving the TIFN definition and aggregation operator, such as triangular intuitionistic weighing arithmetic average (TIWAA) operator and ordered weighted aggregation (TI-OWA)operator. Next, extending the TIFN ranking method by using the weighted average area, the model of multi-attribute group decision is constructed. Finally, a numerical example is given to illustrate application. The numberical results show that the proposed method is feasible and effective. Keywords: Multi-attribute group decision, Triangular intuitionistic fuzzy number, Aggregation operator, Rank.
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Introduction
Intuitionistic fuzzy set by atanassov[1] has widely used to decision making field. It ’s characteristics considered 3 kinds of information at the same time, that are membership, non-membership degree and hesitant degree. To comparing Zadeh’s given fuzzy set, it has the flexibility and practicability in handling fuzzy and uncertainty etc.. It[2-3]expanded intuitionistic fuzzy set to interval-valued intuitionistic fuzzy set; it’s theory[4-6]would apply to multi-attribute group decision; literature[7] defined triangle intuition fuzzy number(TIFN) and its operation, and be applied to a decision tree analysis. For the sake of the science and democracy of decision, in some large or important decision problems, we usually need several decision makers participate in common. Currently, it has seldom reported to multiattribute group decision on TIFN. So this paper gives a new decision method based on TIFN.
