new measure of uncertainty based on knowledge granulation for rough sets

Rough set theory is a relatively new mathematical tool for computer applications in circumstances characterized by gueness and uncertainty. In this paper, we address certainty of rough sets for information systems. An axiom definition of knowledge granulation for information systems is btained, under which a measure of uncertainty of a rough set is proposed. This measure has some nice properties such as equivalence, maximum and minimum. Furthermore, we prove that the uncertainty measure is effective and suitable for easuring roughness and accuracy of rough sets for information systems with a more simple and comprehensive form than the measure defined in [15].