In this paper, we proposed the covering fuzzy rough set model based on multi-granulations and discussed some interesting properties about the model. The research may enlarge the application range of the rough set theory in real life. The lower and upper approximations of fuzzy set are defined by multi-covering relations on the universe, and some basic properties are introduced. It is shown that the fuzzy rough set model based on multi-covering relations is an extension of the rough set model based on multi-granulations.
A Fuzzy Rough Set Model Based on Reliability Over Dual-Universe and Its Applications