Variable precision rough set model based on general relation

To make up for the drawbacks of the rough set model on general relation, a majority inclusion relation is defined and an error parameter /spl alpha/ is introduced in order to give a variable precision rough set model based on general relation. In our rough set model, if /spl alpha/ satisfies some conditions, then the model degenerates the basic rough set model which was first introduced by Z. Pawlak or degenerate the graded rough set model. What follows that model proposed in this paper is an extension of the classical basic rough set based on general relation and graded rough set model. After introducing the error parameter /spl alpha/, more useful information and data are collected and mined. Thus, the drawbacks, which lose more useful information for demanding the inclusion of the absolutely precision in the classical basic rough set model, are overcome.