Modeling of fuzzy comprehensive evaluation based on cloud model

A fuzzy comprehensive evaluation model based on cloud model which can be applied to evaluate air quality was established in this paper. Firstly, the basic content of the cloud model was introduced. The evaluation set, the weight set and the membership degree matrix based on the cloud model were discussed, and the evaluation model was established, which overcame the shortage of traditional fuzzy mathematics that describes these factors with precise numbers. Secondly, the result of the comprehensive evaluation was expressed by the cloud model, in which fuzziness and randomness were considered. Thus, it can avoid the large deviation resulting from maximum membership degree principle used in traditional fuzzy comprehensive evaluation, leading to more precious evaluation results, which correspond to human understanding. Finally, a case study of the comprehensive evaluation model was conducted, in which the air quality can be evaluated effectively.