FT228/4 Knowledge Based Decision Support Systems Rule-Based Systems Ref: Artificial Intelligence A Guide to Intelligent Systems Michael Negnevitsky – Aungier St.
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Transcript FT228/4 Knowledge Based Decision Support Systems Rule-Based Systems Ref: Artificial Intelligence A Guide to Intelligent Systems Michael Negnevitsky – Aungier St.
FT228/4 Knowledge Based
Decision Support Systems
Rule-Based Systems
Ref: Artificial Intelligence A Guide to Intelligent Systems
Michael Negnevitsky – Aungier St. Call No. 006.3
Knowledge
Knowledge is a theoretical or practical
understanding of a particular doamin
Knowledge is the sum of what is
currently know
Those who possess knowledge are
termed experts
Knowledge
What is an expert ?
Deep knowledge
Strong practical experience
How do you represent how experts
think?
Knowledge Representation
Programming language is a means of
representing knowledge
Procedural knowledge
“how to”
Knowledge about how to perform some
task
Declarative knowledge
“what is “
Knowledge Representation
Production Rules
IT-THEN expressions
IF some condition(s) exists THEN
perform some action(s)
Test-Action rules
Rule-Based System = Intelligent
Production System
Knowledge Representation
Rule Part 1
Antecedent (premise or condition)
IF part
Test part
Rule Part 2
Consequent (conclusion or action)
THEN part
Action part
IF <antecedent> THEN <consequent>
A rule fires when its condition part is
satisified and its action part is executed
Knowledge Representation
Rule can have multiple antecedents
Conjunction AND
Disjunction OR
Or a combination of both
Consequent can have multiple clauses
IF <antecedent> THEN <consequent1>
<consequent2>
<consequentn>
Knowledge Representation
Antecedent consists of
An object (linguistic object)
Its value
Linked by an operator
Identifies the object and assigns the value
E.g is, are, is not, are not
Mathematical operators e.g =, >, <
Consequent consists of
An object
A value
Connected by an operator
Knowledge Representation
Rules represent
Relations
Recommendations
Directives
Strategies
Heuristics
Production System Model
Long Term Memory
Short Term Memory
Production Rule
Fact
Reasoning
Conclusion
Rule-Based System for Tic-TacToe
What rules do we need ?
Rules may have tests that are satisfied
at the same time – need some
mechanism for selecting right rule