A New Type of Covering Rough Set

Rough sets, a tool for data mining, deal with the vagueness and granularity in information systems. This paper studies a type of covering generalized rough sets. After presenting their basic properties, this paper explores the inter dependency between the lower and the upper approximation operations, conditions under which two coverings generate a same upper approximation operation, and the axiomatic systems for these operations. In the end, this paper establishes the relationships between this type of covering rough sets and the other covering rough sets in literature