Host: Japan Society for Fuzzy Theory and Intelligent Informatics (SOFT)
We propose a simple calculation method of attribute reduction in variable precision rough set (for short, VPRS) models proposed by Ziarko. VPRS is an extension of Pawlak's rough set theory, and it provides a theoretical basis to treat inconsistent or probabilistic information in the framework of rough sets. Inuiguchi has proposed various types of attribute reduction in VPRS, and Wang and Chiou have proposed a method to calcurate reducts preserving beta-lower approximations (called L-beta-reducts) proposed by Inuiguchi. In this paper, we prove that calculation of L-beta-reducts results in calculation of relative reducts in Pawlak's rough set theory. Moreover, by generating a beta-decision table from the given decision table, we propose a method to calculate all L-beta-reducts in the given decision table by using a discernibility matrix.
