LAUSR

Multi-scale rough set has become one of the hot research topics in rough set. In this article, from the point of view of granule, we first give the definition of the scale relationship between two coverings. Then some properties about neighborhood and approximation operators are explored based on multi-scale covering. Further, we investigate the multi-scale covering approximation space and thus construct a rough set model based on multi-scale covering. In the multi-scale covering decision approximation space, several optimal scale coverings are studied. Finally, we show the connection between multi-scale covering rough sets and multi-scale information systems, and generalize the multi-scale covering approximation space. Rough sets based on multi-scale covering are more extensive than multi-scale information systems. In addition, we design couple of algorithms and several experiments are conducted to verify the efficiency of the algorithms.