The quotient structure in granule computing

The theory of granule computing based on the quotient space is one of the three main granule computing theories. The emphasis is on the structure of the quotient space theory in this paper. Comparing with rough set theory, the authors point out the importance of the structure in granule computing theory. A new method of constructing quotient space according to the structure is also presented in this paper. The differences between the quotient structure and structure-based method are proved. Finally, some examples show the rationality and feasibility of our methods.