The Rough Set Model Based On Tolerance Dominance Relation And Its Application Research

In the complete order information system, it’s too strict and the fault tolerant ability is bad when the classic dominance relation rough set model compares the objects and schemes. So it is necessary to expand the classic dominance relation rough set model. The paper studies the concept and related properties of the extension model. The main research works are as follows:Firstly, in the complete order information system, the article gives the definition of tolerance dominance relation, and proposes the rough set model based on the tolerance dominance relation. When fault tolerance rate is zero, the rough set model based on the tolerance dominance relation degenerates to the classic dominance relation rough set model. Namely the classic dominance relation rough set model is a special form of the rough set model based on the tolerance dominance relation.Secondly, the paper discuss the related properties of the new model, mainly discusses the measurement uncertainty problem of the order information system based on tolerance dominance relation. The article gives the concepts of rough degree, rough entropy and fuzzy degree. Use them to measure the uncertainty of rough set. And there are definite relations and differences between them.Thirdly, the attribute reduction problem of the order information system based on the tolerance dominance relation is studied. To maintain the tolerance dominance class of the order information system the same, the paper gives the definition of attribute reduction under the order information system based on the tolerance dominance relation. According to the definition of attribute reduction, the algorithm of attribute reduction is proposed and its time complexity is analyzed.Fourthly, the project sorting problem of the order information system based on the tolerance dominance relation is studied. Basing on tolerance dominance relation, the definition of dominant degree is obtained and a project sorting method basing on the tolerance dominance relation is proposed. The sorting method is applied to the comprehensively evaluate of smart grid. The results show that compared to the classical dominance relation, the tolerance dominance relation possesses stronger capability of fault tolerance for the data.Finally, in incongruous decision-making order information system, to maintain the relatively coordination of the information system the same, the paper gives the distribution reduction and maximum distribution reduction of the incongruous order information system based on the tolerance dominance relation. The theorem of corresponding reduction decision is presented and its related properties are discussed. In addition, to maintain the deterministic classification of each decision-making class the same in the system, the article gives the lower approximation reduction of the incongruous order information system based on the tolerance dominance relation. And the decision theorem of lower approximation reduction and the calculation method are given.