Download csc 427: artificial intelligence - University of Agriculture, Abeokuta

CSC 427: ARTIFICIAL INTELLIGENCE
BY
DR. A. F. ADEKOYA
Room No: COLNAS B321
Department of Computer Science
College of Natural Sciences
University of Agriculture, Abeokuta
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
1
CSC 427: ARTIFICIAL INTELLIGENCE
Course Contents:
1. Introduction to Artificial Intelligence
2. Overview of Artificial Intelligence Techniques/Tools
3. Descriptive Logic
4. Artificial Neural Network
5. Fuzzy Logic
6. Genetic Algorithm
7. Knowledge Representation, Expert Systems and Pattern
Recognition
8. Natural Language Processing
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
2
CSC 427: ARTIFICIAL INTELLIGENCE
References:
1.
2.
Data Mining: Concepts, Models, Methods, and Algorithms by Mehmed
Kantardzic John Wiley & Sons
ISBN:0471228524 © 2003
Artificial Intelligence and Expert Systems for Engineers
by C.S. Krishnamoorthy; S. Rajeev
CRC Press, CRC Press LLC
ISBN: 0849391253 1996
3.
C++ Neural Networks and Fuzzy Logic
by Valluru B. Rao
M&T Books, IDG Books Worldwide, Inc.
ISBN: 1558515526 1995
4.
Mathematics for Computing
by R. Callan, Letts Educational, London.
ISBN 1-85805-375-7 1998
5.
Artificial Intelligence: A Guide to Intelligent Systems
by Michael Negnevitsky, Addison Wesley Pearson Education
ISBN
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Assessments
1.
2.
3.
4.
Attendance
Assignments
Mid-Semester Exams
Semester Examination
5%
10%
15%
70%
Note:




4/29/2017
Deadlines for submission of assignments are not negotiable and
must be strictly complied with.
Copying of assignments is forbidden and would attract zero mark.
There would be one or two impromptu CAT(s).
75% Attendance is required before a student would be allowed to
sit for the semester examination.
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
4
CSC 427: ARTIFICIAL INTELLIGENCE
Introduction to Artificial Intelligence
Overview:
Computers have been extensively used to expedite or automate
many complex and sometimes dangerous tasks. The history of
the use of computers in problems solving parallels the
developments in computer hardware and software technology.
The emergence of improved paradigms such as evolutionary, soft,
parallel and distributed computing, backed up by appropriate
software environments, has virtually transformed the direction of
research in computer usage. This has resulted in the
transformation of computers from large numerical computing
machines to aids to engineers at every stage of problem solving.
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Introduction to Artificial Intelligence
A key task in problem solving especially with computers at different
stages of execution is decision making.
Decision making requires processing of symbolic information in
handling of facts and inference using domain knowledge.
Inference is nothing but search through the knowledge base using
the facts.
The intensive research carried out in the area of AI in the last six
decades resulted in the emergence of a number of useful
techniques which can be used for solving many complex
problems.
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Introduction to Artificial Intelligence
Intelligence is synonymous with human (animal) ability to store and recall
fact (cognitive), solve a given problem based on known fact and relevant
theorem (psychomotor).
This ability is inherent and innate, trainable and can be developed.
Artificial Intelligence (AI) is the ability of an electronic device (computer) to
accomplish any tasks that ordinary would have been handled by human.
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
7
CSC 427: ARTIFICIAL INTELLIGENCE
Introduction to Artificial Intelligence
AI models the richness and dynamisms of human brain and its analytic
and memory capability.
Artificial Intelligence focus on
(i) the use of computers to process symbols,
(ii) the need for new languages, and
(iii) the role of computers for theorem proving instead of focusing on
hardware that simulated intelligence.
(J. McCarthy, M. Minsky, N. Rochester and C. Shanon 1956)
4/29/2017
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University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Introduction to Artificial Intelligence
Major Categories of AI
1. Symbolic
Based on logic and uses of sequences of rules.
Symbolic programs are good in modeling how human
think, act and accomplish tasks.
2. Connectionist
Based on network of neurons in the brain. Brittle and
good for machine learning and pattern recognition.
3. Evolutionary
Based on genetics evolution theory in biology.
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Introduction to Artificial Intelligence
Purpose of AI
1. Technological
2. Psychological
3. Economic
Home Task
Do a critic of Alan Turing and
John Searle views of AI
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University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Logic
4/29/2017
•
Proposition Logic
•
Predicate Logic
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University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Logic
Proposition Logic
A propositional logic is a logical statement whose truth value can
be evaluated as either TRUE or FALSE.
Where T
denotes TRUE
And
denotes FALSE
F
Propositional logic is of two types, namely
• Simple Propositional Logic
• Complex or Compound Propositional Logic.
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Logic
Simple Propositional Logic
A simple propositional logic refers to single logical statement whose truth
value can be verified or evaluated.
e.g.
UNAAB is a university.
Complex or Compound Propositional Logic
A complex propositional logic refers to logical statements which are
combinations of two or more simple propositional logic statements with
the use of connectors (connectives) such as disjunction, conjunction etc.
e.g.
4/29/2017
UNAAB is a university and it is located in Abeokuta.
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
Logic
Truth Tables
Truth tables are used for stating precise logic values for logic
statements. The number of rows in a truth table is 2n, where n is the
number of simple propositions in the logical statements.
Each of the propositions are given labels such as A, B, C etc.
e.g.
UNAAB is a university
e.g.
UNAAB is a university and it is located in Abeokuta.
A
comprises UNAAB is a university
UNAAB is located in Abeokuta
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
A
B
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CSC 427: ARTIFICIAL INTELLIGENCE
Logic
Symbol
Logic Connectives
Logic uses names and symbols
to represent the connectives as
illustrated in this table.
., 
+, 

Logic Name
Conjunction
AND
Disjunction
OR
Negation
NOT

Implication
Implies

Equivalence
Double
implication

4/29/2017
Connectives
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Exclusive
OR
EX-OR
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CSC 427: ARTIFICIAL INTELLIGENCE
AND Truth Table
e.g.
UNAAB is a university and it is located in Abeokuta.
comprises UNAAB is a university
UNAAB is located in Abeokuta
Connective: AND, .,
Rules of AND
1.
2.
A

B
A AND B
B
A
A.B
The output is
TRUE when all
the inputs are
TRUE.
T
T
T
T
T
T
F
F
F
F
The output is
FALSE if any or
all the inputs are
FALSE
F
T
F
F
F
F
F
F
F
F
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
A
B
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CSC 427: ARTIFICIAL INTELLIGENCE
OR Truth Table
e.g.
Either UNAAB is a university or is a polytechnic.
comprises UNAAB is a university
UNAAB is a polytechnic
Connective: OR, +,
Rules of OR
1.
2.
The output is
TRUE when at
least one or all
the inputs are
TRUE.
The output is
FALSE if all the
inputs are FALSE
4/29/2017
A

B
A OR B
B
A
A+B
T
T
T
T
T
T
F
T
T
T
F
T
T
T
T
F
F
F
F
F
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
A
B
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CSC 427: ARTIFICIAL INTELLIGENCE
NOT Truth Table
e.g.
UNAAB is a university
UNAAB is not a university
Connective: NOT, -,
Rules of OR
The output is a
negation of the input.
i.e. when the
•
•
Input is TRUE, the
output is FALSE.
A
A
A

NOT A
A
-A
T
F
F
F
F
T
T
T
Input is FALSE,
the output is
TRUE.
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
IMPLICATION Truth Table
e.g.
IF UNAAB is a university THEN it is an higher institution.
comprises UNAAB is a university
A
UNAAB is an higher institution
B
Connective: Implies, -,
Rules of Implication
1.
2.
The output is
TRUE when at
least one or all
the inputs are
TRUE.
The output is
FALSE if all the
input are FALSE
4/29/2017
A

B
A Implies B
A B
T
T
T
T
T
F
F
F
F
T
T
T
F
F
T
T
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University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
EQUIVALENCE Truth Table
e.g.
A university degree is equivalent to a polytechnic diploma
Connective: Equivalence, ↔
Rules of Equivalence
1.
2.
3.
A
The output is TRUE
when all the inputs are
TRUE.
The output is TRUE
when all the inputs are
FALSE.
The output is FALSE if
any of the input is FALSE
B
A↔B
T
T
T
T
F
F
F
T
F
F
F
T
Exercise: Using a truth table, prove that (A ↔B) ↔((A ↔B)^(B→A))
4/29/2017
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University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
EXCLUSIVE-OR Truth Table
e.g.
A university degree is equivalent to a polytechnic diploma
Connective: EX-OR,
Rules of Equivalence
1. The output is TRUE
when either at least
an input is TRUE or
FALSE.
2. The output is FALSE if
either all the inputs are
TRUE or all the inputs
are FALSE
4/29/2017
A
B
A
B
T
T
F
T
F
T
F
T
T
F
F
F
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
TAUTOLOGY AND CONTRADICTION
TAUTOLOGY
An expression with a
truth value T
irrespective of the
truth values of the
constituent atoms.
A
B
A ^ B→A
CONTRADICTION
An expression with a
truth value F
irrespective of the
truth values of the
constituent atoms.
A
B
A ^ B→A
T
T
T
T
T
F
T
F
T
T
F
F
F
T
T
F
T
F
F
F
T
F
F
F
4/29/2017
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University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
ARGUMENT AND VALIDITY
Argument: An argument present a conclusion as following logically from a set of
assumptions.
e.g. If we say “John’s keys are in the car or hung up in the office. John’s keys are not
in the car. Then John’s keys are hung up in the office.”
We can always write this argument in a clear and precise formal expression, such
as:
John’s keys are in the car or hung up in the office
John’s keys are in the car
Therefore, John’s keys are hung up in the office
We can express the argument in a more formal form
i.
P νQ } Assumptions
ii.
¬P
iii,
Q
Conclusion
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
P
¬P
Q
Logically, it is written as
PνQ
¬P
Q
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CSC 427: ARTIFICIAL INTELLIGENCE
ARGUMENT AND VALIDITY
Validity of an argument: If we express the argument in the form [ A
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
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CSC 427: ARTIFICIAL INTELLIGENCE
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
25
CSC 427: ARTIFICIAL INTELLIGENCE
4/29/2017
Department of Computer Science,
University of Agriculture, Abeokuta,
Nigeria. www.unaab.edu.ng
26