4. Artificial intelligence (AI) is
the intelligence of machines
and the branch of computer
science that aims to create it.
the study and design of intelligent
agents" where an intelligent
agent is a system that perceives its
environment and takes actions that
maximize its chances of success.
5. What makes a computer
intelligent.:
Speed of computation
Filteration of results
Algorithms:
6. Research in AI has focused on
following components:
LEARNING
REASONING:
UNDERSTANDING
CREATIVITY:
INTUITION:
10. NEED FOR FORMAL LANGUAGES:
“The boy saw a girl with a
telescope”
Symbolic logic is a syntactically
unambigious knowledge
representation language
11. KNOWLEDGE REPRESENTATION
TECHNIQUES IN AI:
PROPOSITIONAL LOGIC
declarative statement
~ -> Negation
→ -> implication
↔ -> implies and implied by
v -> disjunction
^ -> Conjunction
12. SYNTAX:
syntax= how a sentence looks like
Sentence -> AtomicSentence | ComplexSentence
AtomicSentence -> T(RUE) | F(ALSE) | Symbols
ComplexSentence -> ( Sentence ) | NOT Sentence |
Connective -> AND | OR | IMPLIES | EQUIV(ALENT)
Precedence: NOT AND OR IMPLIES EQUIVALENT
conjunction disjunction implication equivalence
negation
13. Semantics:
semantics= what a sentence means
interpretation:
assigns each symbol a truth value, either
t(rue) or f(alse)
the truth value of T(RUE) is t(rue)
the truth value of F(ALSE) is f(alse)
14. Terminology:
A sentence is valid if it is True under all
possible assignments of
True/False to its propositional variables (e.g.
P_:P)
Valid sentences are also referred to as
tautologies
15. Semantic Networks:
l Graph structures that encode taxonomic
knowledge of objects and their properties.
– objects represented as nodes
– relations represented as labeled edges
l Inheritance = form of inference in which
subclasses inherit properties of
superclasses
17. NORMAL Form in predicate LOGIC
Rule:-
1. Replace and by using equivalent
formulas.
2. Repeated use of negation
~(~p)=F.Demorgan’s law to bring negation in
front of each atom.
~ (GF)= ~G~F.Use ~x F(x)= x~F(x) and
~xF(x) = x~F(x)
Then use all the equivalent expressions to
bring the quantities in front of the expressions
18. Resolution in predicate LOGIC:
i) R(a)
ii) R(x) M(x,b)
First replace a in place of x in 2nd premise and
conclude M(a,b).
e.g:
Marcus was a man. Man (marcus)
Marcus was a Pompeian. Pompeian (Marcus)
Caesar was a ruler. Ruler (Caesar)
20. Principles of NMRs :
If x is not known, then conclude y
If x cannot be proved, then conclude y
e.g. 1: To build a program that generates a
solution to a fairly a simple problem.
e.g. 2: To find out a time at which three busy
can all attain a meeting
dependency-directed backtracking
21. Necessity of NMR:
The presence of incomplete information
requires default reasoning.
A changing world must be decided by a
changing database.
Generating a complete solution to a
problem may require temporary assumption
about partial solution.
22. PROCEDURAL Vs DECLARATIVE
KNOWLEDGE:
Advantages of declarative knowledge are:
The ability to use knowledge in ways that
the system designer did not forsee
Advantages of procedural knowledge are:
Possibly faster usage
23.
24. Fundamental Problems of AI
limited acquisition of information
by itself
encodable in “information
structures”
25. CONCLUSION:
Finally we are clear about the
vast spread of the artificial
intelligence in various fields and
the area of knowledge
representation in artificial
intelligence.