Bipolar fuzzy rough set model on two different universes and its application

Pawlak initiated the concept of the rough set as a formal tool for modeling and processing incomplete information in information systems. Various fuzzy generalizations of the rough set have been proposed in the literature. In this paper we generalize the fuzzy rough set model on two different universes proposed by Sun and Ma. Concretely, based on the bipolar fuzzy compatible relation R-(alpha,R-beta) (alpha,beta is an element of (0,1]), the bipolar fuzzy rough set model on two different universes is presented. Some properties of the bipolar fuzzy rough set model are discussed. Two extended models of the bipolar fuzzy rough set model are given, and some related results are obtained. Finally, an example is applied to illustrate the application of the bipolar fuzzy rough set model presented in this paper. (C) 2012 Elsevier By. All rights reserved.