Top Banner
HEURISTIC SEARCH 4 4.0 Introduction 4.1 An Algorithm for Heuristic Search 4.2 Admissibility, Monotonicity, and Informedness 4.3 Using Heuristics in Games 4.4 Complexity Issues 4.5 Epilogue and References 4.6 Exercises Slide 4
10

HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

Jan 18, 2018

Download

Documents

Julian Rodgers

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley Slide 4.3 Figure 4.18: Two-ply minimax and one of two possible MAX second moves, from Nilsson (1971).
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

HEURISTIC SEARCH44.0 Introduction

4.1 An Algorithm for Heuristic Search

4.2 Admissibility, Monotonicity, and Informedness

4.3 Using Heuristics in Games

4.4 Complexity Issues

4.5 Epilogue and References

4.6 Exercises

Slide 4.1

Page 2: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.2

Figure 4.17: Two-ply minimax applied to the opening move of tic-tac-toe, from Nilsson (1971).

Page 3: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.3

Figure 4.18: Two-ply minimax and one of two possible MAX second moves, from Nilsson (1971).

Page 4: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.4

Figure 4.19: Two-ply minimax applied to X’s move near the end of the game, from Nilsson (1971).

Page 5: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.5

Figure 4.20: Alpha-beta pruning applied to state space of Figure 4.15. States without numbers are not evaluated.

Page 6: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.6

Figure 4.21: Number of nodes generated as a function of branching factor, B, for various lengths, L, of solution paths. The relating equation is: T = B(BL - 1)/(B - 1), adapted from Nilsson (1980).

Page 7: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.7

Figure 4.22: Informal plot of cost of searching and cost of computing heuristic evaluation against informedness of heuristic, adapted from Nilsson (1980).

Page 8: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.8

Figure 4.23: The sliding block puzzle.

Page 9: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.9Figure 4.24

Page 10: HEURISTIC SEARCH 4 4.0Introduction 4.1An Algorithm for Heuristic Search 4.2Admissibility, Monotonicity, and Informedness 4.3Using Heuristics in Games 4.4Complexity.

A R T I F I C I A L I N T E L L I G E N C E: Structure and Strategies for Complex Problem Solving, 4th Edition George F. Luger © 2002 Addison Wesley

Slide 4.10Figure 4.25