WebMar 11, 2006 · Firstly, two pairs of covering approximation operators are reviewed, their properties are investigated. Secondly, Based on the covering of the covering approximation space, two new... WebOct 2, 2012 · For a covering of a universe, the closure operator is a closure one of a matroid if and only if the reduct of the covering is a partition of the universe. On the other hand, we investigate the sufficient and necessary condition that the second type of covering upper approximation operation is a closure one of a matroid. READ FULL TEXT
Topological Properties for Approximation Operators in Covering …
WebOct 2, 2012 · In this paper, we connect the second type of covering-based rough sets and matroids from the view of closure operators. On one hand, we establish a closure system through the fixed point family of the second type of covering lower approximation operator, and then construct a closure operator. For a covering of a universe, the closure … WebJun 1, 2012 · Firstly, we generalize the positive (the lower approximation operator), upper approximation, negative and boundary operators of rough sets to the interior, closure, exterior and boundary... mountainsmith ascent hiking backpack
A Theory of Closure Operators - Tufts University
WebMar 15, 2007 · Closure and interior operators are core concepts in topology and they were used to study rough sets [18], [24], [1]. In this paper, we use these topological tools to investigate a new type of rough sets. Definition 1 Coverings. Let U be a domain of discourse, C a family of subsets of U. WebThe closure of a set F of functional dependencies is the set of all functional dependencies logically implied by F. The minimal representation of sets is referred to as the canonical cover: the irreducible set of FD's that describe the closure. Share Improve this answer Follow answered Oct 12, 2016 at 18:37 Ulad Kasach 11k 11 59 84 Add a comment WebJan 20, 2013 · Coverings are a useful form of data, while covering-based rough sets provide an effective tool for dealing with this data. Covering-based rough sets have been widely used in attribute reduction and rule extraction. hearkening part of speech