Firstly,the probability signif- icance of fuzzy systems is revealed. It is pointed out that the COG method,a defuzzification technique used commonly in fuzzy systems,is reasonable and is the optimal method in the sense of mean square.

• 首先揭示Fuzzy系统的概率论意义,指出Fuzzy系统中常用的清晰化方法,即重心法是合理的且在平均平方意义下是最优的方法。