review2 - Exam 2 Review Knowledge Representation Production...

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Exam 2 Review Knowledge Representation Production (Rule-Based) Systems - System components: WM, rule base, inference engine (rule interpreter) - Inference procedure Cycle of three phases: match, conflict-resolution, act/fire Forward and backward inference - Conflict resolution conflict set conflict resolution policies (refraction, specificity, recency, priority/rule-ordering) - Advantages Simplicity (for both language and inference) Efficiency Modularity (easy for KB maintenance) Natural for many application domains - Disadvantages No clearly defined semantics (based on informal understanding) Incomplete inference procedure Unpredictable side effects of ordering of rule applications Less expressive (may not be suitable for some applications) Structured representation - Semantic (associative) networks Labeled nodes: objects, classes, concepts Labeled directed links: relations (associations) between nodes reification Reasoning about associations (marker passing and spreading activation) - ISA hierarchy and property inheritance Super/subclass and instance/class relation Inference by inheritance Multiple inheritance (from different parents, from ancestors of different distances) Exceptions in inheritance/default reasoning - Frame Systems Definition (stereotypical views of the world; record like structure) Slots, their values and facets Procedural attachment and how they work (if-added, if-needed, if-updated)
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This note was uploaded on 05/12/2010 for the course IT expirt taught by Professor Tt during the Spring '10 term at Dubai Aerospace Enterprise University.

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review2 - Exam 2 Review Knowledge Representation Production...

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