Algorithms and Ordering Heuristics for Distributed Constraint Satisfaction Problems

PREFACE ix

INTRODUCTION xiii

PART 1. BACKGROUND ON CENTRALIZED AND DISTRIBUTED CONSTRAINT REASONING 1

CHAPTER 1. CONSTRAINT SATISFACTION PROBLEMS 3

1.1. Centralized constraint satisfaction problems 3

1.3. Summary 28

CHAPTER 2. DISTRIBUTED CONSTRAINT SATISFACTION PROBLEMS 29

2.1. Distributed constraint satisfaction problems 29

2.2. Methods for solving DisCSPs 36

2.3. Summary 47

PART 2. SYNCHRONOUS SEARCH ALGORITHMS FOR DISCSPS 49

CHAPTER 3. NOGOOD-BASED ASYNCHRONOUS FORWARD CHECKING (AFC-NG) 51

3.1. Introduction 51

3.2. Nogood-based asynchronous forward checking 53

3.3. Correctness proofs 59

3.4. Experimental evaluation 60

3.5. Summary 68

CHAPTER 4. ASYNCHRONOUS FORWARD-CHECKING TREE (AFC-TREE) 69

4.1. Introduction 69

4.2. Pseudo-tree ordering 70

4.3. Distributed depth-first search tree construction 72

4.4. The AFC-tree algorithm 75

4.5. Correctness proofs 79

4.6. Experimental evaluation 79

4.7. Other related works 85

4.8. Summary 86

CHAPTER 5. MAINTAINING ARC CONSISTENCY ASYNCHRONOUSLY IN SYNCHRONOUS DISTRIBUTED SEARCH 87

5.1. Introduction 87

5.2. Maintaining arc consistency 88

5.3. Maintaining arc consistency asynchronously 89

5.4. Theoretical analysis 94

5.5. Experimental results 95

5.6. Summary 99

PART 3. ASYNCHRONOUS SEARCH ALGORITHMS AND ORDERING HEURISTICS FOR DISCSPS 101

CHAPTER 6. CORRIGENDUM TO âMIN-DOMAIN RETROACTIVE ORDERING FOR ASYNCHRONOUS
BACKTRACKINGâ 103

6.1. Introduction 103

6.2. Background 104

6.3. ABT_DO-Retro may not terminate 106

6.4. The right way to compare orders 108

6.5. Summary 110

CHAPTER 7. AGILE ASYNCHRONOUS BACKTRACKING (AGILE-ABT) 111

7.1. Introduction 111

7.2. Introductory material 113

7.3. The algorithm 117

7.4. Correctness and complexity 120

7.5. Experimental results 123

7.6. Related works 129

7.7. Summary 130

PART 4. DISCHOCO 2.0: A PLATFORM FOR DISTRIBUTED CONSTRAINT REASONING 131

CHAPTER 8. DISCHOCO 2.0 133

8.1. Introduction 133

8.2. Architecture 134

8.3. Using DisChoco 2.0 137

8.4. Experimentations 140

8.5. Conclusion 142

CONCLUSIONS 143

BIBLIOGRAPHY 147

INDEX 157