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COSC 6368 and “What is AI?” 1. Introduction to AI (today, and TH) • • • What is AI? Sub-fields of AI Problems investigated by AI research 2. Course Information Christoph F. Eick: COSC 6368 and ‘What is AI?” 1 Part1a: Definitions of AI • “AI centers on the simulation of intelligence using computers” • “AI develops programming paradigms, languages, tools, and environments for application areas for which conventional programming fails” – – – – – – Symbolic programming (LISP) Functional programming Heuristic Programming Logical Programming (PROLOG) Rule-based Programming (Expert system shells) Soft Computing (Belief network tools, fuzzy logic tool boxes,…) – Object-oriented programming (Smalltalk) Christoph F. Eick: COSC 6368 and ‘What is AI?” 2 More Definitions of AI • Rich/Knight: ”AI is the study of of how to make computers do things which, at the moment, people do better” • Winston: “AI is the study of computations that make it possible to perceive, reason, and act. • Turing Test: If an artificial intelligent system is not distinguishable from a human being, it is definitely intelligent. Christoph F. Eick: COSC 6368 and ‘What is AI?” 3 Physical Symbol System Hypothesis • “What the brain does can be thought of at some level as a kind of computation” • Physical Symbol System Hypothesis (PSSH): A physical symbol system has the sufficient and necessary means for general, intelligent actions. Remarks PSSH: 1. 2. 3. Subjected to empirical validation If false AI is quite limited Important for psychology and philosophy Christoph F. Eick: COSC 6368 and ‘What is AI?” 4 Questions/Thoughts about AI • What are the limitations of AI? Can computers only do what they are told? Can computers be creative? Can computers think? What problems cannot be solved by computers today? • Computers show promise to control the current waste of energy and other natural resources. • Computer can work in environment that are unsuitable for human beings. • If computers control everything --- who controls the computers? • If computers are intelligent what civil rights should be given to computers? • If computers can perform most of our work; what should the human beings do? • Only those things that can be represented in computers are important. • It is fun to play with computers. Christoph F. Eick: COSC 6368 and ‘What is AI?” 5 Topics Covered in COSC 6368 • More general topics: – heuristic search and search algorithm in general – logical reasoning (FOPL as a language) – making sense out of data • AI-specific Topics: – resolution / theorem proving – reasoning in uncertain environments and belief networks – machine learning and data mining – brief coverage of planning, evolutionary computing, knowledge-based systems and philosophical aspects of AI – Exposure to AI tools (belief networks, decision trees,…) Christoph F. Eick: COSC 6368 and ‘What is AI?” 6 2009 Organization COSC 6368 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Introduction AI and Course Information (1-2 classes) Heuristic Search (4-5 classes) Evolutionary Computing (2 classes) FOPL, Logical Reasoning, Resolution, and PROLOG (3-4 classes) Inductive Learning, Reinforcement Learning, Brief Introduction to Data Mining (4 classes) Knowledge-based Systems and Expert Systems (1 class) Planning (1-2 classes) Ontologies and Philosophical Aspects of AI (1-2 classes) Belief Networks and Reasoning in Uncertain Environments (34 classes) Other Activities: midterm exam (1 class), review (2 classes), homework/project-related discussions(1 class), possibly paper walk-through (1 class). Christoph F. Eick: COSC 6368 and ‘What is AI?” 7 AI in General and What Is not Covered in COSC 6368 • Robotics is a quite important sub-field of AI, but very few teach it in the graduate AI class. • Natural language understanding probably will not be covered. • Intelligent Agents and AI for the Internet could/should possibly be covered in a little more depth. • Artificial intelligence programming is not covered. • Techniques employed in systems that automate decision making in uncertain environments deserves more attention (e.g. fuzzy logic, rule-based programming languages and expert system shells, fuzzy controllers). Christoph F. Eick: COSC 6368 and ‘What is AI?” 8 Positive Forces for AI • Knowledge Discovery in Data and Data Mining (KDD) • Intelligent Agents for WWW • Robotics (Robot Soccer, Intelligent Driving, Robot Waiters, industrial robots, rovers, toy robots…) • Creating of Knowledge Bases and Sharing of Knowledge (especially for Science and Engineering) • Computer Chess and Computer Games in General --- AI for Entertainment Christoph F. Eick: COSC 6368 and ‘What is AI?” 9 6368 Homepage • http://www2.cs.uh.edu/~ceick/6368.html IJCAI 2009 Homepage http://ijcai-09.org/ Christoph F. Eick: COSC 6368 and ‘What is AI?” 10 Course Elements • 21 Lectures • 3 Exams (two midterms, one final exam) • 4 Graded Assignments (review questions, exam style paper and pencil problems, a few more challenging problems that might require programming; problems that require using AI tools; searching for something and reporting) • Un-graded Homeworks (solutions will usually discussed in class) • 1 Paper Walk-Throughs (group activity) if class size <20 • Discussion of assignments and home works • We will try to use more demos and animations --- we have to see if this turns out to be useful Christoph F. Eick: COSC 6368 and ‘What is AI?” 11 Knowledge Representation AI Programming Knowledge-based and Expert Systems Part1b: Planning Coping with Vague, Incomplete and Uncertain Knowledge Logical Reasoning & Theorem Proving Searching Intelligently AI Intelligent Agents & Distributed AI Learning & Knowledge Discovery Communicating, Perceiving and Acting Part1b: Examples of Problems Investigated by Different Subfields of AI Christoph F. Eick: COSC 6368 and ‘What is AI?” 13 Knowledge Representation Problem: Can the above chess board be cover by 31 domino pieces that cover 2 fields? AI’s contribution: object-oriented and frame-based systems, ontology languages, logical knowledge representation frameworks, belief networks Christoph F. Eick: COSC 6368 and ‘What is AI?” 14 Natural Language Understanding • I saw the Golden Gate Bridge flying to San Francisco. • I ate dinner with a friend. I ate dinner with a fork. • John went to a restaurant. He ordered a steak. After an hour John left happily. • I went to three dentists this morning. Christoph F. Eick: COSC 6368 and ‘What is AI?” 15 Planning Objective: Construct a sequence of actions that will achieve a goal. Example: John want to buy a house Christoph F. Eick: COSC 6368 and ‘What is AI?” 16 Heuristic Search • Heuristo (greek): I find • Copes with problems for which it is not feasible to look at all solutions • Heuristics: rules a thumb (help you to explore the more promising solutions first), based on experience, frequently fuzzy • Main ideas of heuristics: search space reduction, ordering solutions intelligently, simplifications of computations Example problems: puzzles, traveling salesman problem, … Christoph F. Eick: COSC 6368 and ‘What is AI?” 17 Figure Christoph F. Eick: COSC 6368 and ‘What is AI?” 18 Evolutionary Computing • Evolutionary algorithms are global search techniques. • They are built on Darwin’s theory of evolution by natural selection. • Numerous potential solutions are encoded in structures, called chromosomes. • During each iteration, the EA evaluates solutions adn generates offspring based on the fitness of each solution in the task. • Substructures, or genes, of the solutions are then modified through genetic operators such as mutation or recombination. • The idea: structures that led to good solutions in previous evaluations can be mutated or combined to form even better solutions. Christoph F. Eick: COSC 6368 and ‘What is AI?” 19 Logical Reasoning • Learn how to represents natural language statements in logic (AI as language) • Automated theorem proving • Foundation for PROLOG Christoph F. Eick: COSC 6368 and ‘What is AI?” 20 Soft Computing Conventional Programming: • Relies on two-valued logic • Mostly uses a symbolic (non-numerical knowledge representation framework) Soft Computing (e.g. Fuzzy Logic, Belief Networks,..): • Tolerance for uncertainty and imprecision • Uses weights, probabilities, possibilities • Strongly relies on numeric approximation and interpolation Remark: There seem to be two worlds in computer science; one views the world as consisting of numbers; the other views the world as consisting of symbols. Christoph F. Eick: COSC 6368 and ‘What is AI?” 21 Different Forms of Learning • Learning agent receives feedback with respect to its actions (e.g. using a teacher) – Supervised Learning/Learning from Examples/Inductive Learning: feedback is received with respect to all possible actions of the agent – Reinforcement Learning: feedback is only received with respect to the taken action of the agent • Unsupervised Learning: Learning without feedback Christoph F. Eick: COSC 6368 and ‘What is AI?” 22 Machine Learning ClassificationModel Construction (1) Training Data NAME M ike M ary B ill Jim D ave A nne RANK YEARS TENURED A ssistant P rof 3 no A ssistant P rof 7 yes P rofessor 2 yes A ssociate P rof 7 yes A ssistant P rof 6 no A ssociate P rof 3 no Christoph F. Eick: COSC 6368 and ‘What is AI?” Classification Algorithms Classifier (Model) IF rank = ‘professor’ OR years > 6 THEN tenured = ‘yes’ 23 Classification Process (2): Use the Model in Prediction Classifier Testing Data Unseen Data (Jeff, Professor, 4) NAME T om M erlisa G eorge Joseph RANK YEARS TENURED A ssistant P rof 2 no A ssociate P rof 7 no P rofessor 5 yes A ssistant P rof 7 yes Christoph F. Eick: COSC 6368 and ‘What is AI?” Tenured? 24 Knowledge Discovery in Data [and Data Mining] (KDD) Let us find something interesting! • Definition := “KDD is the non-trivial process of identifying valid, novel, potentially useful, and ultimately understandable patterns in data” (Fayyad) Christoph F. Eick: COSC 6368 and ‘What is AI?” 25 2. General Course Information Course Id: COSC 6368 Machine Learning Time: TU/TH 1-2:30 Instructor: Christoph F. Eick Classroom: 232 PGH E-mail: [email protected] Homepage: http://www2.cs.uh.edu/~ceick/ Christoph F. Eick: COSC 6368 and ‘What is AI?” Prerequisites Background • Algorithms – basic data structures, complexity… • Sound programming skills (no knowledge of LISP or PROLOG is requred) • Ability to deal with “abstract mathematical concepts” • Basic knowledge of logic would be helpful Christoph F. Eick: COSC 6368 and ‘What is AI?” Textbook http://aima.cs.berkeley.edu/ Christoph F. Eick: COSC 6368 and ‘What is AI?” Grading 2 Exams 4 Assignment 60% 40% Remark: Weights are subject to change NOTE: PLAGIARISM IS NOT TOLERATED. Christoph F. Eick: COSC 6368 and ‘What is AI?” Tentative 2009 Teaching Plan (Subject To Change) Week Topic Jan 20 Introduction / Search Jan 27 Search Feb. 3 Search/Evolutionary Computing (EC) Feb. 10 EC, Logical Reasoning (LR) Feb. 17 LR Feb. 24 LR/Learning from Examples(LFE) March 3 LFE/Reinforcement Learning March 10 Review,/Midterm Exam March 24 Leftovers/Knowledge-based Systems March 31 Ontologies/ Philosophical Foundations of AI April 7 Planning April 14 Reasoning in Uncertain Environments (RIE) April 21 RIE April 28 RIE/Review for Final Exam Remark: Topics in brown color may be skipped or replaced by something else Christoph F. Eick: COSC 6368 and ‘What is AI?” Dates to Remember Dates to remember Events Last day before Spring Break; May 12 Exams March 17 /19 No class (Spring Break) Christoph F. Eick: COSC 6368 and ‘What is AI?” Exams Will be open notes/textbook Will get a review list before the exam Exams will center (80% or more) on material that was covered in the lecture Exam scores will be immediately converted into number grades A few sample exams are available Christoph F. Eick: COSC 6368 and ‘What is AI?” Other UH-CS Courses with Overlapping Contents • • • COSC 6342: Machine Learning • Strong Overlap: Decision Trees, Bayesian Belief Networks, Learning from Examples in general • Medium Overlap: Reinforcement Learning COSC 6335: Data Mining • Overlap: Decision trees, Learning from Examples in general • Preprocessing/Exploratory DA, AdaBoost COSC 6367: Evolutionary Computing • Overlap: Search • We also will have 2 lectures on Evolutionary Computing Christoph F. Eick: COSC 6368 and ‘What is AI?”