A New Extended Rough Set Model Based on the Dynamic Tolerance Relation and Improved Tolerance Degree Calculating Method

A dynamic tolerance relation of extended rough set model is presented on the basis of analyzing the existing models. Firstly, an improved method to calculate the tolerance degree of two objects more objective is given. On this basis, a dynamic tolerance degree parameter is selected in this paper. It can adjust the extended model from equivalence relation to tolerance relation, besides it can adjust its value dynamically according to the dynamic adjustment of data set, so it can enlarge the scale of data which can be disposed by this model and enhance the modelpsilas disposal ability. The UCI database is selected to demonstrate the validity of this new extended model.