Convergence and Knowledge Processing in Multi-Agent Systems Book

1 Introduction 1

1.1 Background to the Research 2

1.2 Approach 2

1.3 Contributions 3

1.4 Reader's Guide to the Book 4

2 Research Issues 5

2.1 Multi-agent Systems 5

2.2 Agent-based Modelling 6

2.3 An Ecosystem Perspective of Multi-agent Systems 7

2.4 Convergence Issues 8

2.5 Interaction and Knowledge Exchange 9

3 Stability of Multi-agent Systems 13

3.1 Introduction 13

3.2 Background 14

3.3 Stability in Games 16

3.3.1 Stochastic Systems Primer 16

3.3.2 Definition of Stability 17

3.3.3 Example Games 18

3.4 Experiments 22

3.4.1 Trading Simulation Model 22

3.4.2 Load Transportation Model 31

3.4.3 Virus Spreading Model 43

3.4.4 The Market Demonstrator 52

3.5 Conclusion 56

3.5.1 Limitations and Future Work 56

3.5.2 Achievements 56

4 The Emergence of Knowledge Exchange: An Agent-based Model of a Software Market 59

4.1 Introduction 59

4.2 Digital Business Ecosystem 60

4.2.1 A DBE Economy 60

4.2.2 Market Efficiency 61

4.3 Background 62

4.3.1 Exchange in Economic Markets 62

4.3.2 The Software Industry 64

4.4 An Agent-based Model of the DBE 65

4.4.1 Agent-based Modelling 65

4.4.2 The Setting 66

4.4.3 Exchange of Services 69

4.4.4 Discussion 71

4.5 Analysis of the Model 72

4.5.1 Service Exchange 72

4.5.2 Market Efficiency 77

4.6 Concluding Remarks 79

5 Collaborative Query Expansion 81

5.1 Introduction 81

5.1.1 Query Expansion 82

5.1.2 Discriminative Document Terms 84

5.2 Term Value 85

5.3 Implementation 86

5.3.1 Initial Phase 87

5.3.2 Stemming 87

5.3.3 Common Word Filtering 87

5.3.4 Term Selection 88

5.4 Evaluation 88

5.4.1 Experiments 89

5.4.2 Evaluation Results 91

5.5 Introducing UserCollaboration for Query Expansion 94

5.5.1 Collaboration Procedure 94

5.5.2 Comparing Sets of Terms 95

5.5.3 Example of Collaboration 96

5.6 Limitations and Future Work 96

5.7 Conclusions 98

6 Micro-economic Control of Distributed Intelligent Personal Assistants 99

6.1 Stable Strategies 99

6.2 Network of Intelligent Personal Assistants 101

6.2.1 Definition of the Automatic PA 101

6.2.2 Further Specifications 102

6.2.3 The Intelligent Automatic PA 103

6.2.4 Negotiating and Optimizing Agents 104

6.2.5 An Example 105

6.3 Finding a Stable Strategy 107

6.3.1 The Discrete Event Simulator 107

6.3.2 A Stable Strategy 108

6.4 Conclusion 114

7 Conclusions and Future Work 117

7.1 Contributions 117

7.2 Future Directions 119

7.2.1 Ecosystems of Networked Businesses 119

7.2.2 Exchange in Natural Ecosystems 120

7.3 Concluding Remarks 121

Appendices 122

A The EEII Project 123

B Statistical Analysis 125

B.1 Statistical Hypothesis Testing 125

B.2 Tests for Showing That Two Samples Come from the Same Distribution 126

C Methodology: Evolutionary Algorithms 129

References 131

Index 141