Rule selections in fuzzy expert systems

摘要

A fuzzy expert system consists of a database of facts and a database of rules of the type: If x is A then y is B. When a fact `x is A′' is given, a generalized modus ponens inference rule is applied to infer `y is B′'. If more than one rule is relevant, this paper suggests that a measure of nearness between A and A′ should be used and a threshold point for invoking a rule be determined in advance. This paper surveys a number of measures of nearness between fuzzy sets and recommends a `better' one for implementation.