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1、1. Introduction To Artificial intelligence,Autumn 2012 Instructor: Wang Xiaolong Harbin Institute of Technology, Shenzhen Graduate School Intelligent Computation Research Center (ICRC, HITSGS),Course Outline,Why Study AI? What is AI? What can AI do? What tasks require AI? How to achieve AI? Branches
2、 of AI Examples of AI AI in China AI in HIT,Why Study AI?,Search engines,Labor,Science,Medicine/ Diagnosis,Appliances,What else?,Why Study AI?(Cont.),Sony AIBO,http:/,Why Study AI?(Cont.),US military,Why Study AI?(Cont.),Natural Language Question Answering,http:/www.ai.mit.edu/projects/infolab/,http
3、:/,Why Study AI?(Cont.),Robot Teams,USC robotics Lab,What is AI?,The exciting new effort to make computers thinks machine with minds, in the full and literal sense” (Haugeland 1985),“The art of creating machines that perform functions that require intelligence when performed by people” (Kurzweil, 19
4、90),“The study of mental faculties through the use of computational models” (Charniak et al. 1985),A field of study that seeks to explain and emulate intelligent behavior in terms of computational processes” (Schalkol, 1990),Systems that think like humans,Systems that think rationally,Systems that a
5、ct like humans,Systems that act rationally,Views of AI fall into four categories:,The textbook advocates “acting rationally“,What is AI?(Cont.),Acting Humanly: The Turing Test Alan Turings 1950 article Computing Machinery and Intelligence discussed conditions for considering a machine to be intellig
6、ent. “Can machines think?” “Can machines behave intelligently?” The Turing test (The Imitation Game): Operational definition of intelligence. Computer needs to possess: Natural language processing, Knowledge representation, Automated reasoning, and Machine learning Predicted that by 2000, a machine
7、might have a 30% chance of fooling a lay person for 5 minutes Anticipated all major arguments against AI in following 50 years,Are there any problems/limitations to the Turing Test?,problems with the Turing Test: Turing test is not reproducible, constructive, and amenable to mathematic analysis. Wha
8、t about physical interaction with interrogator and environment?,What is AI?(Cont.),Acting Humanly: The Full Turing Test The computer passes the test if a human interrogator, after posing some written questions, cannot tell whether the written responses come from a person or not. Requires physical in
9、teraction and needs perception and actuation. What would a computer need to pass the Turing test? Natural language processing: to communicate with examiner. Knowledge representation: to store and retrieve information provided before or during interrogation. Automated reasoning: to use the stored inf
10、ormation to answer questions and to draw new conclusions. Machine learning: to adapt to new circumstances and to detect and extrapolate patterns. Vision (for Total Turing test): to recognize the examiners actions and various objects presented by the examiner. Motor control (total test): to act upon
11、objects as requested. Other senses (total test): such as audition, smell, touch, etc.,What is AI?(Cont.),Thinking Humanly: Cognitive Science 1960 “Cognitive Revolution”: information-processing psychology replaced behaviorism. Cognitive science brings together theories and experimental evidence to mo
12、del internal activities of the brain. What level of abstraction? “Knowledge” or “Circuits”? How to validate models? Predicting and testing behavior of human subjects (top-down) Direct identification from neurological data (bottom-up) Building computer/machine simulated models and reproduce results (
13、simulation) Thinking Rationally: Laws of Thought Aristotle ( 450 B.C.) attempted to codify “right thinking” What are correct arguments/thought processes? E.g., “Socrates is a man, all men are mortal; therefore Socrates is mortal” Several Greek schools developed various forms of logic: notation plus
14、rules of derivation for thoughts.,Problems: Uncertainty: Not all facts are certain (e.g., the flight might be delayed). Resource limitations: - Not enough time to compute/process - Insufficient memory/disk/etc - Etc.,What is AI?(Cont.),Acting Rationally: The Rational Agent Rational behavior: Doing t
15、he right thing! The right thing: That which is expected to maximize the expected return Provides the most general view of AI because it includes: Correct inference (“Laws of thought”) Uncertainty handling Resource limitation considerations (e.g., reflex vs. deliberation) Cognitive skills (NLP, AR, k
16、nowledge representation, ML, etc.) Advantages: More general Its goal of rationality is well defined Rational agents,What Can AI Do?,Quiz: Which of the following can be done at present? Play a decent game of table tennis? Drive safely along a curving mountain road? Drive safely along Telegraph Avenue? Buy a weeks worth of groceries on the web? Buy a weeks worth of groceries at Berkeley Bowl? Discover and prove a new mathematical theorem? C
