Knowledge Acquisition under Imprecision through Neighborhood Approximation Operators
نویسنده
چکیده
The notion of rough sets, introduced by Z. Pawlak in 1982, is to capture impreciseness and indiscernibility of objects. The basic assumption of rough set theory is that human knowledge about a universe depends upon their capability to classify its objects. Classifications (or partitions) of a universe and equivalence relations defined on it are known to be interchangeable notions. So, for mathematical reasons, equivalence relations were considered by Pawlak to define rough sets. But in practice, we can get non-equivalence relations, rather than equivalence relations for the study of approximations. In this paper, we find notion of neighborhood systems instead of equivalence relations, proposed by Lin (1988), Chu (1992) and Lin & Yao (1996), for the study of approximation and also we study some properties of 1-neighborhood systems. General Terms Expert Systems, Rough Set Theory
منابع مشابه
Rough approximation operators based on quantale-valued fuzzy generalized neighborhood systems
Let $L$ be an integral and commutative quantale. In this paper, by fuzzifying the notion of generalized neighborhood systems, the notion of $L$-fuzzy generalized neighborhoodsystem is introduced and then a pair of lower and upperapproximation operators based on it are defined and discussed. It is proved that these approximation operators include generalized neighborhood system...
متن کاملA Novel Method of the Generalized Interval-Valued Fuzzy Rough Approximation Operators
Rough set theory is a suitable tool for dealing with the imprecision, uncertainty, incompleteness, and vagueness of knowledge. In this paper, new lower and upper approximation operators for generalized fuzzy rough sets are constructed, and their definitions are expanded to the interval-valued environment. Furthermore, the properties of this type of rough sets are analyzed. These operators are s...
متن کاملNew Neighborhood Based Rough Sets
Neighborhood based rough sets are important generalizations of the classical rough sets of Pawlak, as neighborhood operators generalize equivalence classes. In this article, we introduce nine neighborhood based operators and we study the partial order relations between twenty-two different neighborhood operators obtained from one covering. Seven neighborhood operators result in new rough set ap...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2011