Rough set models on two universes are valuable generalizations of classic rough set model. These models can be applied into formal concept analysis and decision-making system. This paper focuses on catoptrical approach for rough set models over two universes using granule-based definition. In this paper, we propose a new catoptrical rough set model over dual universes. The properties of the proposed model are discussed. Consequently, a variable precision extension of the model is presented. Some properties of the extended model are obtained. Finally, we investigate a further extension of the proposed model, i.e. variable precision catoptrical rough set model with two parameters.

This work was published on Information Sciences,2017,390:70-81. titled Catoptrical rough set model on two universes using granule-based definition and its variable precision extensions