The IDC Membership Distance between Vague Sets and Its Application

Based on the dynamic tendency of vague sets and the three-dimension of element membership to a vague set, a method of comparing the two vague sets by means of set pair analysis (SPA) is put forward. First, according to the positive, negative and uncertain membership of vague sets, the IDC(Identical Discrepancy Contrary) and weight IDC membership of vague set are defined; then, the IDC and weight IDC membership distance between vague sets are defined; last, the IDC membership distances between vague sets are applied to pattern recognition, which testifies the validity and simplicity of this method.