2. G5BAIM Artificial Intelligence Methods Graham Kendall History

3. G5BAIM History Predictions “Within 10 years a computer will be a chess champion” –Herbert Simon, 1958 Conversion from Russian to English, when presented with –“The spirit is willing but the flesh is weak” produced –“The vodka is good but the meat is rotten” National Research Council, 1957

4. G5BAIM History The Travelling Salesman Problem A salesperson has to visit a number of cities (S)He can start at any city and must finish at that same city The salesperson must visit each city only once The number of possible routes is (n!)/2

5. G5BAIM History Combinatorial Explosion

6. G5BAIM History Combinatorial Explosion

7. G5BAIM History Combinatorial Explosion A 10 city TSP has 181,000 possible solutions A 20 city TSP has 10,000,000,000,000,000 possible solutions A 50 City TSP has 100,000,000,000,000,000,000,000,000,000,00 0,000,000,000,000,000,000,000,000,000,000 possible solutions There are 1,000,000,000,000,000,000,000 litres of water on the planet Mchalewicz, Z, Evolutionary Algorithms for Constrained Optimization Problems, CEC 2000 (Tutorial)

8. G5BAIM History Combinatorial Explosion - Towers of Hanoi

9. G5BAIM History Combinatorial Explosion - Towers of Hanoi

10. G5BAIM History Combinatorial Explosion - Towers of Hanoi

11. G5BAIM History Combinatorial Explosion - Towers of Hanoi

12. G5BAIM History Combinatorial Explosion - Towers of Hanoi

13. G5BAIM History Combinatorial Explosion - Towers of Hanoi

14. G5BAIM History Combinatorial Explosion - Towers of Hanoi

15. G5BAIM History Combinatorial Explosion - Towers of Hanoi

16. G5BAIM History Combinatorial Explosion - Towers of Hanoi How many moves does it take to move four rings? You might like to try writing a towers of hanoi program (and you may well have to in one of your courses!)

17. G5BAIM History Combinatorial Explosion - Towers of Hanoi If you are interested in an algorithm here is a very simple one Assume the pegs are arranged in a circle 1. Do the following until 1.2 cannot be done –1.1 Move the smallest ring to the peg residing next to it, in clockwise order –1.2 Make the only legal move that does not involve the smallest ring 2. Stop P. Buneman and L.Levy (1980). The Towers of Hanoi Problem, Information Processing Letters, 10, 243-4

18. G5BAIM History Combinatorial Explosion - Towers of Hanoi A time analysis of the problem shows that the lower bound for the number of moves is 2 N -1 Since N appears as the exponent we have an exponential function

19. G5BAIM History Combinatorial Explosion - Towers of Hanoi

20. G5BAIM History Combinatorial Explosion - Towers of Hanoi The original problem was stated that a group of tibetan monks had to move 64 gold rings which were placed on diamond pegs. When they finished this task the world would end. Assume they could move one ring every second (or more realistically every five seconds). How long till the end of the world?

21. G5BAIM History Combinatorial Explosion - Towers of Hanoi > 500,000 years!!!!! Or 3 Trillion years Using a computer we could do many more moves than one second so go and try implementing the 64 rings towers of hanoi problem. If you are still alive at the end, try 1,000 rings!!!!

22. G5BAIM History Combinatorial Explosion - Optimization Optimize f(x 1, x 2,…, x 100 ) where f is complex and x i is 0 or 1 The size of the search space is 2 100  10 30 An exhaustive search is not an option –At 1000 evaluations per second –Start the algorithm at the time the universe was created –As of now we would have considered 1% of all possible solutions

23. G5BAIM History Combinatorial Explosion Microseconds in a Day Microseconds since Big Bang

24. G5BAIM History Combinatorial Explosion 102050100200 N2N2 N5N5 1/10,000 second 1/2500 second 1/400 second 1/100 second 1/25 second 1/10 second 3.2 seconds 5.2 minutes 2.8 hours 3.7 days 2N2N N 1/1000 second 1 second 35.7 years > 400 trillion centuries 45 digit no. of centuries 2.8 hours 3.3 trillion years 70 digit no. of centuries 185 digit no. of centuries 445 digit no. of centuries Running on a computer capable of 1 million instructions/second Ref : Harel, D. 2000. Computer Ltd. : What they really can’t do, Oxford University Press

25. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally

26. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally Top Left=Cognitive Science

27. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally Top Left=Cognitive Science Bottom Left=The Turing Test

28. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally Top Left=Cognitive Science Bottom Left=The Turing Test Top Right=Logical Approach

29. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally Top Left=Cognitive Science Bottom Left=The Turing Test Top Right=Logical Approach Bottom Right=Acting to achieve one’s goals

30. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally Top=Thought Processes and Reasoning

31. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally Top=Thought Processes and Reasoning Bottom=Behaviour

32. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally Top=Thought Processes and Reasoning Bottom=Behaviour Left=Measure success against ourselves

33. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally Top=Thought Processes and Reasoning Bottom=Behaviour Left=Measure success against ourselves Right=Measure against rationality

34. G5BAIM History Definition of AI Systems that think like humans Systems that think rationally Systems that act like humans Systems that act rationally

35. G5BAIM History Not Examinable - but in notes Turing Test Chinese Room Physical Symbol System Hypothesis ELIZA MYCIN Forward/Backward Chaining Means End Analysis

36. G5BAIM Artificial Intelligence Methods Graham Kendall End of History