CRST: A Generalization of Rough Set Theory
نویسندگان
چکیده
The paper presents a transition from the crisp rough set theory to a fuzzy one, called Alpha Rough Set Theory or, in short, a-RST. All basic concepts or rough set theory are extended, i.e., information system, indiscernibility, dependency, reduction, core, de®nability, approximations and boundary. The resulted theory takes into account fuzzy data and allows the approximation of fuzzy concepts. Besides, the control of knowledge granularity is natural in a-RST which is based on a parameterized indiscernibility relation. a-RST is developed to recognize non-deterministic relationships using notions as a-dependency, a-reduct and so forth. On the other hand, we introduce a notion of relative dependency as an alternative of the absolute de®nibility presented in rough set theory. The extension a-RST leads naturally to the new concept of alpha rough sets which represents sets with fuzzy non-empty boundaries. Ó 2000 Elsevier Science Inc. All rights reserved.
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