Fuzzy decision algorithm based on rough sets

A method of acquiring fuzzy decision rules from continuous domain decision system is proposed. First, we transform the continuous attributes value into the fuzzy value with fuzzy membership functions. Second, we give the definition of similarity degree of two objects of continuous condition attributions. Third, the definitions of similarity relation and similarity class of each object are given. According to the lambda-similarity relation, we give lower and upper approximations of rough-fuzzy approximation space and their properties. At last, we put forward a method of discovering fuzzy decision rules from continuous domain decision table by combining rough sets and fuzzy sets. Also, we verified the validity of this new algorithm through an example of effectiveness evaluation of the self-repairing flight control system.