Means-Ends Analysis
Allows both backward and forward searching.This means we could solve major parts of a problem first and then return to smaller problems when assembling the final solution.GPS was the first…
And-Or Graphs
Useful for certain problems where The solution involves decomposing the problem into smaller problems.We then solve these smaller problems. Here the alternatives often involve branches where some or all must…
Heuristic Search
A heuristic is a method that might not always find the best solutionbut is guaranteed to find a good solution in reasonable time. By sacrificing completeness it increases efficiency.Useful in solving tough problems…
Problems and Search
Problem solving involves: problem definition -- detailed specifications of inputs and what constitutes an acceptable solution;problem analysis;knowledge representation;problem solving -- selection of best techniques. Problem Definition In order to solve…
Frames
Frames can also be regarded as an extension to Semantic nets. Indeed it is not clear where the distinction between a semantic net and a frame ends. Semantic nets initially…
Why use this data structure?
It enables attribute values to be retrieved quicklyassertions are indexed by the entitiesbinary predicates are indexed by first argument. E.g. team(Mike-Hall , Cardiff).Properties of relations are easy to describe .It allows…
Extending Semantic Nets
Here we will consider some extensions to Semantic nets that overcome a few problems (see Exercises) or extend their expression of knowledge. Partitioned Networks Partitioned Semantic Networks allow for: propositions to be…
Inference in a Semantic Net
Basic inference mechanism: follow links between nodes. Two methods to do this: Intersection search -- the notion that spreading activation out of two nodes and finding their intersection finds relationships among objects. This…
Representation in a Semantic Net
The physical attributes of a person can be represented as in Fig. 9. Fig. 9 A Semantic Network These values can also be represented in logic as: isa(person, mammal), instance(Mike-Hall, person) team(Mike-Hall, Cardiff) We…
SEMANTIC NETS
A semantic net (or semantic network) is a knowledge representation technique used for propositional information. So it is also called a propositional net. Semantic nets convey meaning. They are two dimensional representations of knowledge. Mathematically a semantic…
