关键词: 优势关系, 多粒度, 粗糙集, 近似精度, 优势度

Abstract: The classical rough set is based on single granulation（equivalence relation）from the perspective of granular computing, It is extended to the multi-granulation rough set based on dominance relation, and the approximate upper and lower are defined. By comparison of the classical rough set, more properties and conclusions based on two-granulation and multi-granulation are got. And the boundary, approximate accuracy, dominance measure, general dominance measure in rough set are studied. Some examples of seismic data are given to illustrate the differences between single-granulation and multi-granulation.

Key words: dominance relation, multi-granulation, rough set, approximate accuracy, dominance measure