Lecture 01

AI: Chapter 1: Introduction 1
Artificial Intelligence
Chapter 1: Introduction
Naveed Anwer Butt
Department of Computer Science
University of Gujrat

Goals of this Course
• Become familiar with AI techniques, including
their implementations
– Be able to develop AI applications
• Python,
• Understand the theory behind the techniques,
knowing which techniques to apply when (and
why)
• Become familiar with a range of applications of
AI, including “classic” and current systems.

What is Intelligence?
• Main Entry: in·tel·li·gence
Pronunciation: in-'te-l&-j&n(t)s
Function: noun
Etymology: Middle English, from Middle French, from Latin intelligentia, from intelligent-,
intelligens intelligent
• 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) b Christian Science
: the basic eternal quality of divine Mind c : mental acuteness : SHREWDNESS
• 2 a : an intelligent entity; especially : ANGEL b : intelligent minds or mind <cosmic intelligence>
• 3 : the act of understanding : COMPREHENSION
• 4 a : INFORMATION, NEWS b : information concerning an enemy or possible enemy or an
area; also : an agency engaged in obtaining such information
• 5 : the ability to perform computer functions

What is Artificial Intelligence?
• Not just studying intelligent systems, but
building them…
• Psychological approach: an intelligent
system is a model of human intelligence
• Engineering approach: an intelligent
system solves a sufficiently difficult
problem in a generalizable way

AI prehistory
• Philosophy Logic, methods of reasoning, mind as physical
system foundations of learning, language,
rationality
• Mathematics Formal representation and proof algorithms,
computation, (un)decidability, (in)tractability,
probability
• Economics utility, decision theory
• Neuroscience physical substrate for mental activity
• Psychology phenomena of perception and motor control,
experimental techniques
• Computer building fast computers
engineering
• Control theory design systems that maximize an objective
function over time
• Linguistics knowledge representation, grammar

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

(again)

(again)
• Systems that think like
humans
– Cognitive Modeling Approach
– “The automation of activities
that we associate with human
thinking...”
– Bellman 1978
• Systems that act like
humans
– Turing Test Approach
– “The art of creating machines
that perform functions that
require intelligence when
performed by people”
– Kurzweil 1990
• Systems that think
rationally
– “Laws of Thought” approach
– “The study of mental faculties
through the use of
computational models”
– Charniak and McDermott
• Systems that act rationally
– Rational Agent Approach
– “The branch of CS that is
concerned with the
automation of intelligent
behavior”
– Lugar and Stubblefield

Acting Humanly
• The Turing Test
(1950)
– Can machines think?
– Can machines behave
intelligently?
• Operational test for
intelligent behavior
– The Imitation Game
Human
AI System
Human
Interrogator
?

Acting Humanly
• Turing Test (cont)
– 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
• Problem!
– The turning test is not reproducible, constructive, or
amenable to mathematical analysis

Thinking Humanly
• 1960’s cognitive revolution
• Requires scientific theories of internal activities
of the brain
– What level of abstraction? “Knowledge” or “Circuits”
– How to validate?
• Predicting and testing behavior of human subjects (top-
down)
• Direct identification from neurological data (bottom-up)
• Cognitive Science and Cognitive Neuroscience
– Now distinct from AI

Acting Rationally
• Rational behavior
– Doing the right thing
• What is the “right thing”
– That which is expected to maximize goal
achievement, given available information
• Doesnot necessary involve thinking –e.g.,
blinking reflex-but involve thinking should be in
the service of rational action.
• We do many (“right”) things without thinking
– Thinking should be in the service of rational action

Applied Areas of AI
• Heuristic Search
• Computer Vision
• Adversarial Search (Games)
• Fuzzy Logic
• Natural Language Processing
• Knowledge Representation
• Planning
• Learning

Examples
• Playing chess
• Driving on the
highway
• Mowing the lawn
• Answering questions
• Recognizing speech
• Diagnosing diseases
• Translating languages
• Data mining

Heuristic Search
• Very large search space
– Large databases
– Image sequences
– Game playing
• Algorithms
– Guaranteed best answer
– Can be slow – literally years
• Heuristics
– “Rules of thumb”
– Very fast
– Good answer likely, but not guaranteed!
• Searching foreign intelligence for terrorist activity.

Computer Vision
• Computationally taxing
– Millions of bytes of data
per frame
– Thirty frames per second
• Computers are scalar /
Images are
multidimensional
• Image Enhancement vs.
Image Understanding
• Can you find the terrorist
in this picture?

Adversarial Search
• Game theory...
– Two player, zero sum – checkers, chess, etc.
• Minimax
– My side is MAX
– Opponent is MIN
• Alpha-Beta
– Evaluation function...”how good is board”
– Not reliable...play game (look ahead) as deep as
possible and use minimax.
– Select “best” backed up value.
• Where will Al-Qaeda strike next?

Adversarial Search
X X O
O
X
X X O
O O
X
X X O
O O
X
X X O
O O
X X
X X O
O O
X X
X X O
O O X
X
X X O
O O
X X
X X O
O O
X X
X X O
X O O
X
1
2 6
3 4 5 7 8 9
1-0=1 1-2=-1 1-1=0 *91* 0 10
...MAX
MIN

Example: Tic Tac Toe #1
move
table
encode look
up
• Precompiled move
table.
• For each input
board, a specific
move (output
board)
• Perfect play, but is
it AI?

• Represent board as a magic square, one integer
per square
• If 3 of my pieces sum to 15, I win
• Predefined strategy:
– 1. Win
– 2. Block
– 3. Take center
– 4. Take corner
– 5. Take any open square

• Given a board, consider all possible moves (future
boards) and pick the best one
• Look ahead (opponent’s best move, your best move…)
until end of game
• Functions needed:
– Next move generator
– Board evaluation function
• Change these 2 functions (only) to play a different
game!

Fuzzy Logic
• Basic logic is binary
– 0 or 1, true or false, black or white, on or off,
etc...
• But in the real world there are of “shades”
– Light red or dark red
– 0.64756
• Membership functions

Fuzzy Logic
Appetite
Light Moderate Heavy
0
1
Calories Eaten Per Day
Membership
Grade
1000 2000 3000
Linguistic
Variable
Linguistic
Values

Natural Language Processing
• Speech recognition vs. natural language processing
– NLP is after the words are recognized
• Ninety/Ten Rule
– Can do 90% of the translation with 10% time, but 10% work
takes 90% time
• Easy for restricted domains
– Dilation
– Automatic translation
– Control your computer
• Say “Enter” or “one” or “open”
– Associative calculus
• Understand by doing

Natural Language Processing
S1 S2 S3“The big grey dog”
Net for Basic Noun Group
determiner noun
adjective
S1 S2 S3“by the table in the corner”
Net for Prepositional Group
preposition NOUNG
S1 S2 S3“The big grey dog by the
table in the corner”
Net for Basic Noun Group
determiner noun
adjective
PREPG

Knowledge Representation
• Predicate Logic
– On(table, lamp)
– In(corner, table)
– Near(table, dog)
– Prolog
• Graph Based
– Semantic Networks
– Frames
• Rule Based
– Expert Systems

Planning
• Robotics
– If a robot enters a
room and sits down,
what is the “route”.
• Closed world
• Rule based systems
• Blocks world
Table
Chair

Planning
• Pickup(x)
– Ontable(x), clear(x),
handempty(),
– Holding(x)
• Putdown(x)
– Holding(x)
– Ontable(x), clear(x),
handempty()
• Stack(x, y)
– Holding(x), clear(y)
– Handempty(), on(x, y),
clear(x)
• Unstack(x, y)
– Handempty(), clear(x), on(x,
y)
– Holding(x), clear(x)
A
C
B
Robot
Hand
B
A
C
Clear(B) On(C, A) OnTable(A)
Clear(C) Handempty OnTable(B)
Goal: [On(B, C) ^ On(A, B)]

Learning
• Neural Networks
• Evolutionary Computing
• Knowledge in Learning
• Reinforcement Learning

Listening Assignment
• https://www.youtube.com/watch?v=16Dir
4QqCUg

Lecture 01

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Lecture 01