Research on the Grey Rough Set Modeling and Its Properties Using Constructive Method

Based on the combination of rough set (RS) theory and grey system (GS) theory, this paper presents the grey-rough set modeling using constructive method (CM). Considering grey system theory having good ability in data preprocessing, grey number is used to describe the imprecise, uncertain, vague information in the information system through grey mapping, and then the grey information system is built. In this paper, CM is applied to investigate the RS. the definition of four pairs of approximate operators of grey rough set (GRS) is proposed using CM. At the same time, we investigated the GRS-related fundamental theory and delivered the algebra system of the GRS. It makes that the methods of GS classification can be used to describe the incomplete information more precisely, and enhance the ability of grey information covering, and therefore the connotative knowledge and rule in grey information system can be discovered more effectively and exactly.