POSSIBILISTIC EXPERT SYSTEMS AND PROCESS CONTROL UTILIZING FUZZY LOGIC

摘要

An explicit assumption of continuity is used to generate a fuzzy implication operator, which yields an envelope of possibility for the conclusion. A sing le fuzzy rule A?B entails an infinite set of possible hypothese A'?B' whose degree of consistency with the original rule is a function of the "distance" between A and A' and the "distance" between B and B'. This distance may be measured geometrically or by set union/intersection. As the distance between A and A' increases, the possibility distribution B* spreads further outside B somewhat like a bell curve, corresponding to common sense reasoning about a continous process. The manner in which this spreading occurs is controlled b y parameters encoding assumptions about (a) the maximum possible rate of chang e of B' with respect to A'(b) the degree of conservatism or speculativeness desired for the reasoning process (c) the degree to which the process is continuous or chaotic.