关键词: 粗糙集理论, 非完备信息系统, 不可区分度, 组合熵, 组合粒度

Abstract: Combination entropy and combination granulation are a new kind of methods for measuring the uncertainty of an information system.In this paper，the forms of the combination entropy and the combination granulation，based on the indiscernibility between elements，are first constructed for imperfect information systems，as well as some of their properties are discussed.Then，the relationship between the combination entropy and the combination granulation is established as well.It is proved that the combination entropy and the combination granulation of imperfect information systems will degenerate into those of complete information systems.An illustrative example shows that the method proposed by this paper can effectively measure the uncertainty of imperfect information systems and extend the application range of combination entropy and combination granulation.

Key words: rough set theory, imperfect information systems, indiscernibility, combination entropy, combination granulation