Скачать презентацию CS 531 AI CS 331 Introduction to AI Скачать презентацию CS 531 AI CS 331 Introduction to AI

57956e8dbc51255b13adeb90be37adc0.ppt

  • Количество слайдов: 47

CS 531: AI CS 331: Introduction to AI Dr Mian Muhammad Awais Room 416 CS 531: AI CS 331: Introduction to AI Dr Mian Muhammad Awais Room 416 [email protected] edu. pk Robotics and Intelligent Computing (RICE), Group CS 531: Dr M M Awais (LUMS)

Course Description Course home page: TBA Contacts: lecture notes, tutorials, assignment, grading, office hours, Course Description Course home page: TBA Contacts: lecture notes, tutorials, assignment, grading, office hours, etc. Textbooks: 1) Luger: Artificial Intelligence: Structures and Strategies for Complex Problem-solving Fourth Edition (Available as Reading package) 2) S. Russell and P. Norvig Artificial Intelligence: A Modern Approach Prentice Hall, 2003, First or Second Edition (HANDOUTS) Grading: Quizzes (15%) Practice (15%), Midterm test (30%) Final exam (40%) Practice Options: • At least 2 Lab Assignments where attendance will be compulsory and will be taken. • Critical reviews of interesting papers • Take Home/In class Assignments (LISP/PROLOG) CS 531: Dr M M Awais (LUMS)

TA Support/Office Hours • TA 1: Umar Faiz (umerf@lums. edu. pk) Office hours (TBA, TA Support/Office Hours • TA 1: Umar Faiz ([email protected] edu. pk) Office hours (TBA, see the website) • TA 2: TBA • Instructor Office Hours (room 416): 3 to 4 PM Every day except Friday [email protected] eu. pk CS 531: Dr M M Awais (LUMS)

Course Outline (Core Areas) Very Basic • Introduction and Problem Solving (Today’s Lecture) • Course Outline (Core Areas) Very Basic • Introduction and Problem Solving (Today’s Lecture) • Part I: Knowledge Representation • Part II: Informed Search Methods • Part III: Planning / Reasoning/Expert Systems • Part IV: Learning CS 531: Dr M M Awais (LUMS)

Course Outline (Specialized Areas) • To be decide as the course progresses • Some Course Outline (Specialized Areas) • To be decide as the course progresses • Some options are: – NLP – Speech Processing (On going project at LUMS, 1. 0 million, 3 years) – Agent Technology (Submitted project, 5. 9 million, 3 years) – Imitative Learning (On going project at LUMS, 4. 3 million, 3 years) – Case Based Reasoning – etc CS 531: Dr M M Awais (LUMS)

Course Format • Each Class 100 minutes not 75 minutes • Core Areas: – Course Format • Each Class 100 minutes not 75 minutes • Core Areas: – – – Basic stuff, same as CS 331, will go through it quickly, tested with take home assignments, Midterm and finals will have at least 60% from the core areas. • Special Areas: – High level brief discussion, – tested with assignments, quizzes, – maximum of 40% covered in exams CS 531: Dr M M Awais (LUMS)

Book Chapters • Book Chapters and articles will be announced as we go along Book Chapters • Book Chapters and articles will be announced as we go along • Slides will be available at the website and in the common’s folder • Details to be announced later CS 531: Dr M M Awais (LUMS)

Informal Feedback Mechanism LETS IMPROVE AS WE MARCH • Roughly Every Two Weeks an Informal Feedback Mechanism LETS IMPROVE AS WE MARCH • Roughly Every Two Weeks an anonymous questionnaire will be circulated to evaluate the course • Your comments will be welcomed to improve the course as we go along (DONOT WAIT TILL THE END) • Course progress discussion CS 531: Dr M M Awais (LUMS)

Questions CS 531: Dr M M Awais (LUMS) Questions CS 531: Dr M M Awais (LUMS)

TWO PURPOSES of AI. One is to use the power of computers to augment TWO PURPOSES of AI. One is to use the power of computers to augment human thinking, just as we use motors to augment human or horse power. Robotics and expert systems are major branches of that. The other is to use a computer's artificial intelligence to understand how humans think. In a humanoid way. If you test your programs not merely by what they can accomplish, but how they accomplish it, they you're really doing cognitive science; you're using AI to understand the human mind. Herbert Simon CS 531: Dr M M Awais (LUMS)

AI Dimensions 1) Modeling: Thought process/reasoning vs. behavior/action 2) Evaluation: Success according to human AI Dimensions 1) Modeling: Thought process/reasoning vs. behavior/action 2) Evaluation: Success according to human standards vs. success according to an ideal concept of intelligence rationality CS 531: Dr M M Awais (LUMS)

What is AI? Views of AI fall into four categories: Thinking humanly Thinking rationally What is AI? Views of AI fall into four categories: Thinking humanly Thinking rationally Acting humanly Acting rationally CS 531: Dr M M Awais (LUMS)

Thinking humanly “Can machines think like humans” • Requires scientific theories of internal activities Thinking humanly “Can machines think like humans” • Requires scientific theories of internal activities of the brain, psychological experiments are required • Studied in Cognitive Modeling CS 531: Dr M M Awais (LUMS)

Thinking humanly: cognitive modeling • 1960 s Thinking humanly: cognitive modeling • 1960 s "cognitive revolution": information-processing psychology • Validation Requires • Predicting and testing behavior of human subjects (top-down) • Direct identification from neurological data -up) • Cognitive Science and Cognitive Neuroscience • Distinct from AI CS 531: Dr M M Awais (LUMS) (bottom

Thinking humanly: Some References – – Daniel C. Dennet. Consciousness explained. M. Posner (edt. Thinking humanly: Some References – – Daniel C. Dennet. Consciousness explained. M. Posner (edt. ) Foundations of cognitive science Francisco J. Varela et al. The Embodied Mind J. -P. Dupuy. The mechanization of the mind CS 531: Dr M M Awais (LUMS)

Thinking rationally “Laws of Thought” “Can machines think rationally” Several Greek schools developed various Thinking rationally “Laws of Thought” “Can machines think rationally” Several Greek schools developed various forms of logic: notation and rules of derivation for thoughts; may or may not have proceeded to the idea of mechanization CS 531: Dr M M Awais (LUMS)

Thinking rationally Aristotle: what are correct arguments/thought processes? Mathematics and Philosophy to Modern AI Thinking rationally Aristotle: what are correct arguments/thought processes? Mathematics and Philosophy to Modern AI Problems: 1. Not all intelligent behavior is mediated by logical deliberation 2. What is the purpose of thinking? What thoughts should I have? A reference; ¨ Ivan Bratko, Prolog programming for artificial intelligence. CS 531: Dr M M Awais (LUMS)

Acting humanly “Can machines behave like Humans? ” “Why and How” is not important Acting humanly “Can machines behave like Humans? ” “Why and How” is not important Do what ever you can CS 531: Dr M M Awais (LUMS)

Acting humanly: Turing Test • Turing (1950) Acting humanly: Turing Test • Turing (1950) "Computing machinery and intelligence" • Operational test for intelligent behavior: the Imitation Game • Predicted that by 2000, a machine might have a 30% chance of fooling a lay person for 5 minutes • Anticipated all major arguments against AI in following 50 years • Suggested major components of AI: knowledge, reasoning, language understanding, learning CS 531: Dr M M Awais (LUMS)

CS 531: Dr M M Awais (LUMS) CS 531: Dr M M Awais (LUMS)

Objections : - Turning Test Most AI Programs Are Not Flexible In Nature May Objections : - Turning Test Most AI Programs Are Not Flexible In Nature May Not Be Able to Answer Emotional Questions CS 531: Dr M M Awais (LUMS)

Chinese Room • The Turing Test was the first attempt at resolving the question Chinese Room • The Turing Test was the first attempt at resolving the question of machine intelligence. • It was a behavioral test, judging intelligence based not on inner processes, or faithfulness to neuronal structure, but purely on a computer's ability to verbally communicate. • This approach elicited numerous objections: – Why should behaviour be the final test on intelligence – How can behavior suffice if the internal mechanisms controlling it are nothing like a human being's? – How can a conversation capture all of human intelligence? • These questions essentially reduced themselves to the question of whether one could pass the Turing Test, that is, produce passable conversational speech, while still possessing no 'real' intelligence. This argument has been stated in numerous ways, but perhaps none more eloquent than John Searle's Chinese Room metaphor. http: //psych. utoronto. ca/%7 Ereingold/courses/ai/ CS 531: Dr M M Awais (LUMS)

Searle Counter Example • Imagine a room, with a man trapped inside. The man Searle Counter Example • Imagine a room, with a man trapped inside. The man speaks no Chinese. Someone slips a piece of paper under the door with Chinese writing on it. • Having puzzled over it for a moment, he notices that there is a book in the room titled "What to do if someone slides some Chinese writing under the door. " • The book, he finds, is actually an enormous set of instructions for producing new Chinese symbols based on what comes in. The rules instruct him on how to produce new Chinese symbols, based on the ones received. They are all if-then type statements describing a pattern in the text and the appropriate action or response. • He follows these rules, using the piece of paper handed to him, and produces a new sheet, which he slides back under the door. • The next day, another sheet comes in, he passes the completed sheet back out. • Outside, the world is amazed that this room can actually understand Chinese, that the room is intelligent. Inside though, we CS 531: Dr M M Awais (LUMS) know that the man understands no Chinese whatsoever!

Conclusion What Searle describes is a system that produces intelligent, meaningful output, in the Conclusion What Searle describes is a system that produces intelligent, meaningful output, in the absence of true understanding. If you accept this counterexample, then the Turing Test is doomed. The Chinese Room would pass the Turing test, even though it lacks understanding and intelligence. Searle's argument has, naturally, produced its own share of furious debate, and several strong counter-arguments have been levelled at it. CS 531: Dr M M Awais (LUMS)

References 1. http: //psych. utoronto. ca/%7 Ereingold/cour ses/ai/cache/chineser. htm 2. http: //psych. utoronto. ca/%7 References 1. http: //psych. utoronto. ca/%7 Ereingold/cour ses/ai/cache/chineser. htm 2. http: //psych. utoronto. ca/%7 Ereingold/cour ses/ai/cache/searle. html 3. http: //consc. net/online 2. html (best resource) CS 531: Dr M M Awais (LUMS)

Acting rationally “Can machines behave rationally” • Rational behavior: doing the right thing • Acting rationally “Can machines behave rationally” • Rational behavior: doing the right thing • The right thing: that which is expected to maximize goal achievement, given the available information • Doesn't necessarily involve thinking – e. g. , blinking reflex – but thinking should be in the service of rational action CS 531: Dr M M Awais (LUMS)

What is AI? Views of AI fall into four categories: Thinking humanly Thinking rationally What is AI? Views of AI fall into four categories: Thinking humanly Thinking rationally Acting humanly Acting rationally Our Focus is "ACTING RATIONALLY" RATIONALLY CS 531: Dr M M Awais (LUMS)

Rational Agents • An agent is an entity that perceives and acts • Every Rational Agents • An agent is an entity that perceives and acts • Every thing to be discussed should be taken in the context of : RATIONAL AGENTS • Abstractly, an agent is a function from percept histories to actions: [f: P* A] • For a given class of environments/tasks, Rational Agents sought best performance CS 531: Dr M M Awais (LUMS)

Limitations: Rational Agents Computational limitations make perfect rationality unachievable References Michael Wooldridge. Reasoning about Limitations: Rational Agents Computational limitations make perfect rationality unachievable References Michael Wooldridge. Reasoning about rational agents. Design best program for given machine resources CS 531: Dr M M Awais (LUMS)

Definition: AI Systems Artificial Systems that behave rationally Or limited rationality CS 531: Dr Definition: AI Systems Artificial Systems that behave rationally Or limited rationality CS 531: Dr M M Awais (LUMS)

Other Aspects Read it yourself CS 531: Dr M M Awais (LUMS) Other Aspects Read it yourself CS 531: Dr M M Awais (LUMS)

Another Definition: AI? Computer based solution of complex problems through the application of processes Another Definition: AI? Computer based solution of complex problems through the application of processes that are analogous to the Human Intelligence More inclined towards acting and thinking humanly CONTROVERSIAL ISSUE (How to define Intelligence? ) CS 531: Dr M M Awais (LUMS)

Intelligence Reasoning + - Establishes Relationships - Perception and Comprehension - Generalization Ability Learning Intelligence Reasoning + - Establishes Relationships - Perception and Comprehension - Generalization Ability Learning - Memory/Differentiation Chair vs Table Spoon vs Fork Intelligent Beings Intelligent Systems CS 531: Dr M M Awais (LUMS)

Intelligence Manifestation of intelligence is through Behavior CS 531: Dr M M Awais (LUMS) Intelligence Manifestation of intelligence is through Behavior CS 531: Dr M M Awais (LUMS)

AI Though Groups Strong Believers Weak Believers CS 531: Dr M M Awais (LUMS) AI Though Groups Strong Believers Weak Believers CS 531: Dr M M Awais (LUMS)

Weak AI? Computation Consciousness Brain has ingredients that are Ñ Non - computational Ñ Weak AI? Computation Consciousness Brain has ingredients that are Ñ Non - computational Ñ Simulating consciousness is not possible Computational + Non Computational BRAIN CS 531: Dr M M Awais (LUMS)

Strong AI ? Consciousness - “is some complicated computation” “Computers can achieve or even Strong AI ? Consciousness - “is some complicated computation” “Computers can achieve or even exceed all Human Capacities once high computational speeds are achieved” Brains Are Computers of MEAT? CS 531: Dr M M Awais (LUMS)

Strong and Weak AI 1. http: //www. ecs. soton. ac. uk/~harnad/Paper s/Py 104/searle. comp. Strong and Weak AI 1. http: //www. ecs. soton. ac. uk/~harnad/Paper s/Py 104/searle. comp. html CS 531: Dr M M Awais (LUMS)

Scope of AI Based Techniques Main focus Problems that do not have algorithmic solutions, Scope of AI Based Techniques Main focus Problems that do not have algorithmic solutions, or are very complex Vague, uncertain and poor-defined systems Systems with decision - making problems (Examples? ) CS 531: Dr M M Awais (LUMS)

Example Tasks Game Playing Ñ Ñ Ñ Rules are well defined algorithmic solutions are Example Tasks Game Playing Ñ Ñ Ñ Rules are well defined algorithmic solutions are very complex Formalization is easy Automated Reasoning Ñ Ñ Theorem proving Formal logic/ knowledge representation. Diagnostic Knowledge Expert Systems Mimic experts such as doctors Experts CS 531: Dr M M Awais (LUMS) Coding

Natural Language Processing Ñ Ñ Ñ Computer learn human languages Machine Translation Speech Synthesis Natural Language Processing Ñ Ñ Ñ Computer learn human languages Machine Translation Speech Synthesis Planning And Robotics Ñ Ñ Artificial Pets. Efforts to make “machines” - Responsive - Flexible e. g. , Path Planning CS 531: Dr M M Awais (LUMS) Human Machine

Summary: AI? • Innovative Extension of Philosophy: – Understand BUILD intelligent entities • Formal Summary: AI? • Innovative Extension of Philosophy: – Understand BUILD intelligent entities • Formal Origin after WWII • Highly interdisciplinary • Variety of subfields – This course will discuss some of them CS 531: Dr M M Awais (LUMS)

AI prehistory • Philosophy • Mathematics • • • Economics Neuroscience Psychology • • AI prehistory • Philosophy • Mathematics • • • Economics Neuroscience Psychology • • Computer engineering Control theory • Linguistics Logic, methods of reasoning, mind as physical system foundations of learning, language, rationality Formal representation and proof algorithms, computation, (un)decidability, (in)tractability, probability Utility, decision theory Physical substrate for mental activity Phenomena of perception and motor control, experimental techniques Building fast computers Design systems that maximize an objective function over time Knowledge representation, grammar CS 531: Dr M M Awais (LUMS)

History of AI • • • 1943 1950 1956 1952— 69 1950 s • History of AI • • • 1943 1950 1956 1952— 69 1950 s • • 1965 1966— 73 • • • 1969— 79 1980 -- 1986 -- 1987 -1995 -- Mc. Culloch & Pitts: Boolean circuit model of brain Turing's "Computing Machinery and Intelligence" Dartmouth meeting: "Artificial Intelligence" adopted Look, Ma, no hands! Early AI programs, including Samuel's checkers program, Newell & Simon's Logic Theorist, Gelernter's Geometry Engine Robinson's complete algorithm for logical reasoning AI discovers computational complexity Neural network research almost disappears Early development of knowledge-based systems AI becomes an industry Neural networks return to popularity AI becomes a science The emergence of intelligent agents CS 531: Dr M M Awais (LUMS)

State of the art AI • Deep Blue defeated the reigning world chess champion State of the art AI • Deep Blue defeated the reigning world chess champion Garry Kasparov in 1997 • Proved a mathematical conjecture (Robbins conjecture) unsolved for decades • No hands across America (driving autonomously 98% of the time from Pittsburgh to San Diego) • During the 1991 Gulf War, US forces deployed an AI logistics planning and scheduling program that involved up to 50, 000 vehicles, cargo, and people • NASA's on-board autonomous planning program controlled the scheduling of operations for a spacecraft • Proverb solves crossword puzzles better than most humans CS 531: Dr M M Awais (LUMS)

First Reading Assignment (Write a Two Page Summary on What you think AI is) First Reading Assignment (Write a Two Page Summary on What you think AI is) Submission: Email the article to Instructor /TA by Friday 5: 00 pm (or in folder submission_1 in Cs 531 AI) 1. Luger’s Chapter One: Introduction Other References: Alexander Igor’s Impossible minds (Help Material Available in the Library) CS 531: Dr M M Awais (LUMS)

Topics Covered Today • Luger (Some of the discussion is from Stuart and Norvig) Topics Covered Today • Luger (Some of the discussion is from Stuart and Norvig) – Part I – Chapter 1 – Articles 1. 1 to 1. 4 • Practice: – Attempt Exercise Questions – Especially: Qs 1 to 7, 10 to 12 CS 531: Dr M M Awais (LUMS)