In this paper,we first introduce vague set,then give the definition of intersection and unionbased on vague set with t-norm and t-conorm of the point value. Thus we gain some properties of inter-section and union of vague set.
In this paper we propose a new similarity measures in order to overcome some problems in [1],and proposethe idea for similarity direction of vague sets by which to describe which one is more accurate between vague sets. Atsame time we propose a method to determine the similarity direction. Based on above,we present a new bidirectionalapproximate reasoning approach on vague set that fully uses the message accuracy of vague set. So this improves theaccruacy and applicability of approximate reasoning. This provides a useful tool for approximate reasoning in intelli-gence system.
