关键词: 粗糙集理论, 不完备信息系统, 空值, 群体决策

Abstract: To deal with shortcomings in null value estimation method based on similarity relationship model, an improved method was proposed from the perspective of group decision. The direction-area of attributes and simple-majority-rule ratio of objects were defined, and they were combined with null values estimation. Thus completion of incomplete information system was realized without using the voting tactic of original method, moreover the problems such as “objects have no tolerance class” and latent “multimode” or “no mode” of voting tactic were eliminated, and the estimation results of proposed method were better than those of original method on coverage and accuracy. The results of a numerical example and an instance demonstrated the effectiveness of proposed method.

Key words: rough set theory, incomplete information systems, null values, group decision