Artificial Intelligence Introduction



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tarix16.11.2017
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Artificial Intelligence

  • Introduction

  • Chapter 1, AIMA


What you’ll learn from this course

  • What is meant by AI

    • What tools are used
    • What problems are approached
  • How problems can be solved (exactly and approximately) with search

    • Game playing
  • How knowledge can be represented

    • Symbolic (e.g. logic)
    • Non-symbolic (e.g. neural networks)
  • How logical reasoning (under certainty and under uncertainty) can be done with a machine.

  • How a machine can learn (machine learning)



Course structure

  • 20 hrs. of lectures [T Rögnvaldsson]

  • Exercises (programming) [P-Å Jovall]

  • Homework (with feedback) [T Rögnvaldsson]

  • Examination project (tournament)

    • Play poker against each other [P-Å Jovall]
  • Oral exam [T Rögnvaldsson]

  • You are expected to be active with homework (programming and analysis)

  • The content follows the AIMA book closely



Course web page

  • http://www2.hh.se/staff/denni/courses/AI/aiCourse07.html

  • Will be linked from my home page

  • http://islab.hh.se/islab/islab/people/rognvaldsson.html





What is done in AI?

  • Game Playing (Deep Blue Chess program, TD-gammon, …)

  • Handwriting recognition (Apple, IBM, Microsoft,...)

  • Speech Recognition (PEGASUS spoken language interface to American Airlines’ EAASY SABRE reservation system, Apple interface, …)

  • Human-computer interaction (COG, KISMET)

  • Navigation & problem solving (NASA Rover, MARS Beagle)

  • Computer Vision (Face recognition, ALVINN,…)

  • Expert Systems

  • Diagnostic Systems (Microsoft Office Assistant in Office 97)

  • Planning/scheduling (DARPA DART, ARPI)

  • Web search tools (Google,...)

  • Games and movies (eg. Lord of the Rings, Age of Empires, ...)



The ”pong” video arcade game











Do humans play chess differently?

  • Compare with HAL (the computer in ”2001: A Space Odyssey”). HAL plays ”tricky” and exploits the lower level of the opponent (the Astronaut Poole).

  • This is not ”computer-like”, but ”human-like”.

  • Computers, on the other hand, assume that the opponent will make the best possible move.



An early chess machine

  • Wolfgang von Kempelen

  • “The Turk”: A doll in Turkish costume seated at a desk with a chessboard. (constructed in 1769)

  • It was first demonstrated that no one was concealed inside, then the mechanism was wound up and the machine set in operation (rewinding every 12 moves).

  • It almost always won the chess game.



An early chess machine

  • Wolfgang von Kempelen

  • “The Turk”: A doll in Turkish costume seated at a desk with a chessboard. (constructed in 1769)

  • It was first demonstrated that no one was concealed inside, then the mechanism was wound up and the machine set in operation (rewinding every 12 moves).

  • It almost always won the chess game.





Black & White



Black & White







HCI: COG & Kismet





Navigating: Under water



Autonomous driving on earth





Navigating: Vacuum cleaners



Navigating: helping elderly



Navigating: Waiters??



Navigating: Web search

  • Google

  • ...and more



DARPA Military planning











What is AI?

  • “A field that focuses on developing techniques to enable computer systems to perform activities that are considered intelligent (in humans and other animals).” [Dyer]

  • “The science and engineering of making intelligent machines, especially intelligent computer programs. It is related to the similar task of using computers to understand human intelligence, but AI does not have to confine itself to methods that are biologically observable.” [McCarthy]

  • “The design and study of computer programs that behave intelligently.” [Dean, Allen, & Aloimonos]

  • “AI, broadly defined, is concerned with intelligent behavior in artifacts. Intelligent behavior, in turn, involves perception, reasoning, learning, communicating, and acting in complex environments.” [Nilsson]

  • “The study of [rational] agents that exist in an environment and perceive and act.” [Russell & Norvig]



What is AI?



What is AI?



What is AI?



What is AI?



What is AI?



What is AI?



The Turing test – acting like a human

  • Suggested by Alan Turing in 1950.

  • If the interrigator cannot distinguish the human from the machine (robot), solely on the basis of their answers to questions, then the machine can be assumed intelligent.



The Turing test provides...

  • An objective notion of intelligence

    • No discussion on the ”true” nature of intelligence.
  • A way to avoid confusion by looking at how the computer reasons, or if it is conscious.

  • A way to avoid bias in favour of the human, by just focusing on the written answers.

  • The Turing test can of course be generalized to other fields besides conversation.

  • But it focuses too much on human behavior. We are not trying to build humans (we already know how to do this...)



Problems with Turing test

  • A test of the judge as well of the AI machine

  • Promotes imitators (con-artists).

  • See www.loebner.net

  • Chat bots: http://www.abenteuermedien.de/jabberwock/index.php http://www.alicebot.org/

  • http://www-ai.ijs.si/eliza-cgi-bin/eliza_script

  • http://www.simonlaven.com/



Chat bots...



Applied AI – the 20 questions game

  • Check out: http://www.20q.net/



AI as ”rational agent”

  • We will focus on general principles of rational agents and how to construct them.

    • We can define rational as ”achieving the best outcome” where we measure the outcome. Clearly defined and also general.
    • We don’t have to meddle with what is ”human”.


Fundamental issues in AI

  • Representation

    • Facts about the world have to be represented in some way. Logic is one language that is used in AI. How should knowledge be structured? What is explicit, and what must be inferred? How to encode "rules" for inference so as to find information that is only implicitly known? How deal with incomplete, inconsistent, and probabilistic knowledge?
  • Search

    • Many tasks can be viewed as searching a very large problem space for a solution. Use of heuristics and constraints.
  • Inference

    • Some facts can be inferred from other facts.
  • Learning

    • Learning is essential in an intelligent system.
  • Planning

    • Starting with general facts about the world, about the effects of basic actions, about a particular situation, and a statement of a goal, generate a strategy for achieving the goal.


Some discussion

  • Exercise 1.1:

  • Define in your own words: (a) intelligence, (b) artificial intelligence, and (c) agent.

  • (a) “1 a (1) : the ability to learn or understand or to deal with new or trying situations : also : the skilled use of reason (2) : the ability to apply knowledge to manipulate one's environment or to think abstractly as measured by objective criteria (as tests) … 5 : the ability to perform computer functions”

  • (Merriam-Webster on-line dictionary)



Some discussion

  • Exercise 1.1:

  • Define in your own words: (a) intelligence, (b) artificial intelligence, and (c) agent.

  • (a) “1 a (1) : the ability to learn or understand or to deal with new or trying situations : REASON; also : the skilled use of reason (2) : the ability to apply knowledge to manipulate one's environment or to think abstractly as measured by objective criteria (as tests) … 5 : the ability to perform computer functions”

  • (Merriam-Webster on-line dictionary)



Some discussion

  • Exercise 1.1:

  • Define in your own words: (a) intelligence, (b) artificial intelligence, and (c) agent.

  • (b) We define artificial intelligence as the study and construction of agent programs that perform well in a given environment, for a given agent architecture. mother mummy … Mix

  • (Merriam-Webster on-line dictionary)



Some discussion

  • Exercise 1.1:

  • Define in your own words: (a) intelligence, (b) artificial intelligence, and (c) agent.

  • (c) We define an agent as an entity that takes action in response to percepts from an environment. apply knowledge to manipulate one's environment or to think abstractly as measured by objective criteria (as tests) … 5 : the ability to perform computer functions”

  • (Merriam-Webster on-line dictionary)



More discussion

  • Exercise 1.10:

  • Are reflex actions rational? Are they intelligent?



More discussion

  • Exercise 1.10:

  • Are reflex actions rational? Are they intelligent?

  • Yes, they are rational. Intelligent? Well, thinking before removing your hand from a hot stove might be considered stupid. However, no reasoning is needed so perhaps it isn’t intelligent.




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