TY - BOOK AU - NIlsson, Nils J. TI - Artificial intelligence: A new synthesis SN - 9781558604674 U1 - 006.3 PY - 1998/// CY - Burlington, MA PB - Morgan Kaufmann Publishers, Elsevier KW - Artificial intelligence KW - Knowledge representation and reasoning KW - Neural networks N1 - Includes bibliography and index; Introduction 1.1 What Is AI? 1.2 Approaches to Artificial lntelligence 1.5 Brief History of AI 1.4 Plan of the Book 1.5 Additional Readings and Discussion I Reactive Machines Stimulus-Response Agents 2.1 Perception and Action 2.1.1 Perception 2.1.2 Action 2.1.3 Boolean Algebra 2.1.4 Classes and Forms of Boolean Functions 2.2 Representing and Implementing Action Functions 27 2.2.1 Production Systems 27 2.2.2 Networks 29 2.2.5 The Subsumption Architecture 32 2.5 Additional Readings and Discussion 33 Neural Networks 57 3.1 Introduction 37 3.2 Training Single TLUs 38 3.2.1 TLU Geometry 38 3.2.2 Augmented Vectors 39 3.2.3 Gradient Descent Methods 39 3.2.4 The Widrow-Hoff Procedure 41 3.2.5 The Generalized Delta Procedure 41 3.2.6 The Error-Correction Procedure 43 3.3 Neural Networks 44 3.3.1 Motivation 44 3.3.2 Notation 45 3.3.3 The Backpropagation Method 46 3.3.4 Computing Weight Changes in the Final Layer 48 3.3.5 Computing Changes to the Weights in Intermediate Layers 3.4 Generalization, Accuracy, and Overfitting 51 3.5 Additional Readings and Discussion 54 Machine Evolution 59 4.1 Evolutionary Computation 59 4.2 Genetic Programming 60 4.2.1 Program Representation in GP 60 4.2.2 The GP Process 4.2.3 Evolving a Wall-Following Robot 65 4.5 Additional Readings and Discussion 69 State Machines 5.1 Representing the Environment by Feature Vectors 71 5.2 Elman Networks 5.5 Iconic Representations 74 5.4 Blackboard Systems 77 5.5 Additional Readings and Discussion 6.1 Introduction 6.2 Steering an Automobile 6.5 Two Stages of Robot Vision 6.4 Image Processing 6.4.1 Averaging 6.4.2 Edge Enhancement 6.4.3 Combining Edge Enhancement with Averaging 6.4.4 Region Finding 6.4.5 Using Image Attributes Other Than Intensity 101 6.5 Scene Analysis 6.5.1 Interpreting Lines and Curves in the Image 6.5.2 Model-Based Vision 6.6 Stereo Vision and Depth Information 108 6.7 Additional Readings and Discussion HO II Search in State Spaces 115 7 Agents That Plan 117 7.1 Memory Versus Computation 117 1.1 State-Space Graphs 118 7.3 Searching Explicit State Spaces 121 7.4 Feature-Based State Spaces 122 7.5 Graph Notation 124 7.6 Additional Readings and Discussion 125 8 Uninformed Search 129 8.1 Formulating the State Space 129 8.2 Components of Implicit State-Space Graphs 150 8.3 Breadth-First Search 131 8.4 Depth-First or Backtracking Search 133 8.5 Iterative Deepening 135 8.6 Additional Readings and Discussion 136 9 Heuristic Search 139 9.1 Using Evaluation Functions 139 9.2 A General Graph-Searching Algorithm 141 9.2.1 Algorithm A* 142 9.2.2 Admissibility of A* 145 9.2.3 The Consistency (or Monotone) Condition 150 9.2.4 Iterative-Deepening A* 9.2.5 Recursive Best-First Search 154 9.3 Heuristic Functions and Search Efficiency 155 9.4 Additional Readings and Discussion 160 Planning, Acting, and Learning 165 10.1 The Sense/Plan/Act Cycle 165 10.2 Approximate Search 165 10.2.1 Island-Driven Search 166 10.2.2 Hierarchical Search 167 10.2.3 Limited-Horizon Search 169 10.2.4 Cycles 10.2.5 Building Reactive Procedures 170 10.3 Learning Heuristic Functions 172 10.3.1 Explicit Graphs 172 10.3.2 Implicit Graphs 175 10.4 Rewards Instead of Goals 175 10.5 Additional Readings and Discussion 177 Alternative Search Formulations and Applications 11.1 Assignment Problems 181 11.2 Constructive Methods 185 11.3 Heuristic Repair 187 11.4 Function Optimization 189 Adversarial Search 195 12.1 Two-Agent Games 195 12.2 The Minimax Procedure 197 12.5 The Alpha-Beta Procedure 202 12.4 The Search Efficiency of the Alpha-Beta Procedure 207 12.5 Other Important Matters 208 12.6 Games of Chance 208 12.7 Learning Evaluation Functions 210 12.8 Additional Readings and Discussion 212 Ill Knowledge Representation and Reasoning 215 The Propositional Calculus 217 13.1 Using Constraints on Feature Values 217 15.2 The Language 219 15.5 Rules of Inference 220 15.4 Definition of Proof 221 15.5 Semantics 222 15.5.1 Interpretations 222 13.5.2 The Propositional Truth Table 225 13.5.3 Satisfiability and Models 224 13.5.4 Validity 224 13.5.5 Equivalence 225 13.5.6 Entailment 225 15.6 Soundness and Completeness 226 15.7 The PSAT Problem 227 15.8 Other Important Topics 228 13.8.1 Language Distinctions 228 13.8.2 Metatheorems 22H 13.8.3 Associative Laws 22*^ 13.8.4 Distributive Laws 15.1 Motivation 15.2 The Language and Its Syntax 15.5 Semantics 15.5.4 Knowledge 15.4 Quantification 15.5 Semantics of Quantifiers Resolution in the Propositional Calculus 231 14.1 A New Rule of Inference: Resolution 231 14.1.1 Clauses as wlfs 14.1.2 Resolution on Clauses 14.1.3 Soundness of Resolution 14.2 Converting Arbitrary wffs to Conjunctions of Clauses 14.5 Resolution Refutations 14.4 Resolution Refutation Search Strategies 14.4.1 Ordering Strategies 14.4.2 Refinement Strategies 14.5 Horn Clauses 15.3 The Predicate Calculus 259 15.3.1 Worlds 15.3.2 Interpretations 15.3.3 Models and Related Notions 243 15.5.1 Universal Quantifiers 246 15.5.2 Existential Quantifiers 247 15.5.3 Useful Equivalences 15.5.4 Rules of Inference 15.6 Predicate Calculus as a Language for Representing Knowledge 248 15.6.1 Conceptualizations 15.6.2 Examples 248 15.7 Additional Readings and Discussion 250 Resolution in the Predicate Calculus 255 16.1 Unification 255 16.2 Predicate-Calculus Resolution 256 16.5 Completeness and Soundness 257 16.4 Converting Arbitrary wffs to Clause Form 257 16.5 Using Resolution to Prove Theorems 260 16.6 Answer Extraction 261 16.7 The Equality Predicate 262 16.8 Additional Readings and Discussion 265 Knowledge-Based Systems 269 Confronting the Real World 269 Reasoning Using Horn Clauses 270 Maintenance in Dynamic Knowledge Bases 275 17.4 Rule-Based Expert Systems 280 17.5 Rule Learning 286 17.5.1 Learning Prepositional Calculus Rules 286 17.5.2 Learning First-Order Logic Rules 291 17.5.3 Explanation-Based Generalization 295 17.6 Additional Readings and Discussion 297 Representing Commonsense Knowledge 18.1 The Commonsense World 18.1.1 What Is Commonsense Knowledge? 18.1.2 Difficulties in Representing Commonsense Knowledge 18.1.3 The Importance of Commonsense Knowledge 18.1.4 Research Areas 18.2 Time 18.3 Knowledge Representation by Networks 18.5.1 Taxonomic Knowledge 18.3.2 Semantic Networks 18.3.3 Nonmonotonic Reasoning in Semantic Networks 309 18.3.4 Frames 18.4 Additional Readings and Discussion Reasoning with Uncertain Information 517 19.1 Review of Probability Theory 19.1.1 Fundamental Ideas 19.1.2 Conditional Probabilities 19.2 Probabilistic Inference 19.2.1 A General Method 19.2.2 Conditional Independence 19.5 Bayes Networks 19.4 Patterns of Inference in Bayes Networks 19.5 Uncertain Evidence 19.6 D-Separation 19.7 Probabilistic Inference in Polytrees 532 19.7.1 Evidence Above 19.7.2 Evidence Below 19.7.3 Evidence Above and Below 336 19.7.4 A Numerical Example 336 19.8 Additional Readings and Discussion 358 Learning and Acting with Bayes Nets 345 20.1 Learning Bayes Nets 343 20.1.1 Known Network Structure 343 20.1.2 Learning Network Structure 346 20.2 Probabilistic Inference and Action 351 20.2.1 The General Setting 351 20.2.2 An Extended Example 552 20.2.5 Generalizing the Example 556 20.5 Additional Readings and Discussion 358 IV Planning Methods Based on Logic 361 The Situation Calculus 363 21.1 Reasoning about States and Actions 563 21.2 Some Difficulties 367 21.2.1 Frame Axioms 367 21.2.2 Qualifications 369 21.2.3 Ramifications 369 21.3 Generating Plans 369 21.4 Additional Readings and Discussion 570 Planning 575 22.1 STRIPS Planning Systems 373 22.1.1 Describing States and Goals 373 22.1.2 Forward Search Methods 374 22.1.3 Recursive STRIPS 376 22.1.4 Plans with Run-Time Conditionals 379 22.1.5 The Sussman Anomaly 380 22.1.6 Backward Search Methods 381 22.2 Plan Spaces and Partial-Order Planning 385 22.3 Hierarchical Planning 393 22.3.1 ABSTRIPS 393 22.3.2 Combining Hierarchical and Partial-Order Planning 395 22.4 Learning Plans 396 22.5 Additional Readings and Discussion 398 V Communication and Integration 405 Multiple Agents 407 25.1 Interacting Agents 407 25.2 Models of Other Agents 408 23.2.1 Varieties of Models 408 23.2.2 Simulation Strategies 410 23.2.3 Simulated Databases 410 23.2.4 The Intentional Stance 411 25.5 A Modal Logic of Knowledge 412 23.3.1 Modal Operators 412 23.3.2 Knowledge Axioms 413 25.5.3 Reasoning about Other Agents'Knowledge 415 25.5.4 Predicting Actions of Other Agents 417 23.4 Additional Readings and Discussion 417 Communication among Agents 421 24.1 Speech Acts 421 24.1.1 Planning Speech Acts 425 24.1.2 Implementing Speech Acts 425 24.2 Understanding Language Strings 425 24.2.1 Phrase-Structure Grammars 425 24.2.2 Semantic Analysis 428 24.2.5 Expanding the Grammar 452 24.3 Efficient Communication 435 24.5.1 Use of Context 455 24.5.2 Use of Knowledge to Resolve Ambiguities 456 24.4 Natural Language Processing 437 24.5 Additional Readings and Discussion 440 Agent Architectures 443 25.1 Three-Level Architectures 444 25.2 Goal Arbitration 446 25.3 The Triple-Tower Architecture 448 25.4 Bootstrapping 449 25.5 Additional Readings and Discussion 450 ER -