Rough Set Model Based on Logical OR Operation of Precision and Grade
ZHANG Xian-Yong1, XIONG Fang2, MO Zhi-Wen1
1.College of Mathematics and Software Science, Sichuan Normal University, Chengdu 610068 2.College of Automation, University of Electronic Science and Technology of China, Chengdu 610054
Abstract Precision and grade are two important indexes for quantitative research. The purpose of this paper is to combine precision and grade and explore a new extended rough set model. Transformation formulas of variable precision approximations and graded approximations are obtained by studying the relationship between them. Based on the logical OR requirement of precision and grade, rough set model of logical OR operation of precision and grade and new rough set regions are proposed. In rough set model of logical OR operation of precision and grade, basic structures of rough set regions are gained. The regular algorithm and structure algorithm are proposed and analyzed to calculate rough set regions. The variable precision rough set model, graded rough set model and classical rough set model are extended by the proposed model, and thus these models get corresponding structures of rough set regions.
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2009, Vol. 22 
