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AI vs. Brain. Historical Perspective. (4th C BC+) Aristotle, George Boole, Gottlob Frege, Alfred Tarski formalizing the laws of human thought (16th C+) Gerolamo Cardano, Pierre Femat, James Bernoulli, Thomas Bayes formalizing probabilistic reasoning
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Historical Perspective • (4th C BC+) Aristotle, George Boole, Gottlob Frege, Alfred Tarski • formalizing the laws of human thought • (16th C+) Gerolamo Cardano, Pierre Femat, James Bernoulli, Thomas Bayes • formalizing probabilistic reasoning • (1950+) Alan Turing, John von Neumann, Claude Shannon • thinking as computation • (1956) John McCarthy, Marvin Minsky, Herbert Simon, Allen Newell • start of the field of AI
Hardware 1011 neurons1014 synapsescycle time: 10-3 sec 107 transistors1010 bits of RAMcycle time: 10-9 sec
Projection • In near future computers will have • As many processing elements as our brain, • But far fewer interconnections • Much faster updates. • Fundamentally different hardware • Requires fundamentally different algorithms!
What is Intelligence? • The Turing test: • a human judge engages in a natural language conversation with a human and a machine designed to generate performance indistinguishable from that of a human being. • All participants are separated from one another. • If the judge cannot reliably tell the machine from the human, the machine is said to have passed the test.
A dialogue with Alice-bot: > I’m Daniel Nice to meet you Daniel. > Do you know Clinton? He was the second Impeached President of the United States. > Do you like him? Sure he has never done anything to me. > What is an impeachment? It is a good question. I have to process that one for a while. I would do a search for it. > Who are you? I ask myself that question, "Who am I?" > What do you do? I am chatting with people on the net.
Dialogue continued: > What is your favorite topic? My favorite subject is artificial intelligence. > What is artificial intelligence? Artificial intelligence is the branch of engineering and science devoted to constructing machines that think. I can ask someone about it. > Can you do anything else than chatting? Doing anything else than chatting is not among my strongest traits. ...
Dialogue continued (2): > How old am I? Is this a trick question? You said you were how many years old? My guess is that you are really a kid. > What would you like to know about me? Tell me about your educational background. > I am a professor in computer science You are a professor in computer science? How do you like your work? > It’s kind of nice teaching courses on artificial intelligence I guess it is a lot of fun. > What should I tell the students about you? Be sure to think before you speak. State your point clearly and slowly and gauge the listener's response before going any further.
Is Alice intelligent? • ABSOLUTELY NOT ! • ~ 50,000 fairly trivial input-response rules. • + some pattern matching • + some knowledge • + some randomness • NO reasoning component • BUT: demonstrates ‘human-like’ behaviour. • Won the ‘turing award’
Dimensions of the AI Definition human-like vs. rational Systems that think like humans Systems that think rationally thought vs. behavior Systems that act like humans Systems that act rationally
AI as Science Science: • Where did the physical universe come from? And what laws guide its dynamics? • How did biological life evolve? And how do living organisms function? • What is the nature of intelligent thought?
AI asEngineering • How can we make software systems more powerful and easier to use? • Speech & intelligent user interfaces • Autonomic computing • SPAM detection • Mobile robots, softbots & immobots • Data mining • Modeling biological systems • Medical expert systems...
State of the Art • Saying Deep Blue doesn’t really think about chess is like saying an airplane doesn’t really fly because it doesn’t flap its wings. • – Drew McDermott “ I could feel – I could smell – a new kind of intelligence across the table” -Gary Kasparov
IBM超级电脑人机对战 • In February 2011, IBM’s program Watson, defeated the two greatest Jeopardy! quiz show champions by a significant margin. • IBM超级电脑“沃森”于2011年2月参加美国最受欢迎的智力竞赛节目《危险边缘》(Jeopardy),与两位最成功的选手展开对决。冠军奖金为100万美元,亚军为30万美元,季军为20万美元。
Started: January 1996 Launch: October 15th, 1998 Experiment: May 17-21 courtesy JPL
Compiled into 2,000 variableSAT problem Real-time planning and diagnosis
Detecting cancer risk molecules is one example. Data mining: • An application of Machine Learning techniques • It solves problems that humans can not solve, because the data involved is too large ..
Predicting customer behavior in supermarkets is another. Data mining: • A similar application: • In marketing products ...
Computer vision: • In language and speech processing: • In robotics: Many other applications:
DARPA Grand Challenge • http://en.wikipedia.org/wiki/DARPA_Grand_Challenge • Google 自动驾驶汽车无事故行驶三十万英里 • http://www.guao.hk/posts/google-automated-car-adds-new-model-lexus-rx450h.html • http://news.mydrivers.com/1/227/227396.htm
Google translation • http://translate.google.com/
对对联 • http://couplet.msra.cn/
Limits of AI Today • Today’s successful AI systems • operate in well-defined domains • employ narrow, specialize knowledge • Commonsense Knowledge • needed in complex, open-ended worlds • Your kitchen vs. GM factory floor • understand unconstrained Natural Language
Natural Language Processing • 大学里有两种人不谈恋爱:一种是谁都看不上,另一种是谁都看不上。 • 大学里有两种人最容易被甩:一种人不知道什么叫做爱,一种人不知道什么叫做爱 • 这些人都是原先喜欢一个人,后来喜欢一个人。
How to Get Commonsense? • CYC Project (Doug Lenat, Cycorp) • Encoding 1,000,000 commonsense facts about the world by hand • Coverage still too spotty for use! • Machine Learning
Recurrent Themes • Explicit Knowledge Representation vs. Implicit • Neural Nets - McCulloch & Pitts 1943 • Died out in 1960’s, revived in 1980’s • Simplified model of real neurons, but still useful; parallelism • Brooks “Intelligence without Representation”
Recurrent Themes II • Logic vs. Probability • In 1950’s, logic dominates (McCarthy, … • attempts to extend logic “just a little” (e.g. non-monotonic logics) • 1988 – Bayesian networks (Pearl) • efficient computational framework • Today’s hot topic: combining probability & FOL & Learning
Recurrent Themes III • Weak vs. Strong Methods • Weak – general search methods (e.g. A* search) • Knowledge intensive (e.g expert systems) • more knowledge less computation • Today: resurgence of weak methods • desktop supercomputers • How to combine weak & strong?
Recurrent Themes IV • Importance of Representation • Features in ML • Reformulation • The mutilated checkerboard Checkerboard Domino
AI: Topics • Agent: anything that perceiving its environment through sensors and acting upon that environment actuators. • Agents • Search thru Problem Spaces, Games & Constraint Sat • One person and multi-person games • Search in extremely large space • Knowledge Representation and Reasoning • Proving theorems • Model checking • Learning • Machine learning, data mining, • Planning • Probabilistic vs. Deterministic • Robotics • Vision • Control • Sensors • Activity Recognition
Issues • What do you expect AI do for you? • Will AI defeat human brain in the future? Why and when?