Information structures in a covering information system

A covering information system as the generalization of an information system is an important model in the field of artificial intelligence. This paper explores information structures in a covering information system, and this kind of structure is viewed as a granular structure from the granular computing viewpoint. The concept of information structures in a covering information system is first described by means of set vectors. Then, relationships between information structures in a covering information system are studied from the two aspects of dependence and separation. Next, properties of information structures in a covering information system are given. Furthermore, invariant characterizations of covering information systems under homomorphisms are presented. Finally, as an application for information structures in a covering information system, the granularity measure of uncertainty for covering information systems is investigated. These results will be very helpful for establishing a framework for granular computing in information systems. (C) 2018 Elsevier Inc. All rights reserved.