Some Separations in Covering Approximation Spaces
نویسندگان
چکیده
Adopting Zakowski’s upper approximation operator C and lower approximation operator C, this paper investigates granularity-wise separations in covering approximation spaces. Some characterizations of granularity-wise separations are obtained by means of Pawlak rough sets and some relations among granularitywise separations are established, which makes it possible to research covering approximation spaces by logical methods and mathematical methods in computer science. Results of this paper give further applications of Pawlak rough set theory in pattern recognition and artificial intelligence. Keywords—Rough set, covering approximation space, granularitywise separation.
منابع مشابه
Multigranulation single valued neutrosophic covering-based rough sets and their applications to multi-criteria group decision making
In this paper, three types of (philosophical, optimistic and pessimistic) multigranulation single valued neutrosophic (SVN) covering-based rough set models are presented, and these three models are applied to the problem of multi-criteria group decision making (MCGDM).Firstly, a type of SVN covering-based rough set model is proposed.Based on this rough set model, three types of mult...
متن کاملDefinable Subsets in Covering Approximation Spaces
Covering approximation spaces is a class of important generalization of approximation spaces. For a subset X of a covering approximation space (U, C), is X definable or rough? The answer of this question is uncertain, which depends on covering approximation operators endowed on (U, C). Note that there are many various covering approximation operators, which can be endowed on covering approximat...
متن کاملSOME RESULTS ON t-BEST APPROXIMATION IN FUZZY n-NORMED SPACES
The aim of this paper is to give the set of all t -best approximations on fuzzy n-normed spaces and prove some theorems in the sense of Vaezpour and Karimi [13].
متن کاملt-BEST APPROXIMATION IN FUZZY NORMED SPACES
The main purpose of this paper is to find t-best approximations in fuzzy normed spaces. We introduce the notions of t-proximinal sets and F-approximations and prove some interesting theorems. In particular, we investigate the set of all t-best approximations to an element from a set.
متن کامل