%A ZHANG Wen-juan, LI Jin-jin, LIN Yi-dong
%T Graph-based granularity reduction in pessimistic multi-granulation rough set
%0 Journal Article
%D 2021
%J JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE)
%R 10.6040/j.issn.1671-9352.0.2020.205
%P 60-67
%V 56
%N 1
%U {http://lxbwk.njournal.sdu.edu.cn/CN/abstract/article_3392.shtml}
%8
%X This paper combines the theory of the vertex cover of graph, and a new method of the granularity reduction of pessimistic multi-granulation rough set is discussed. Firstly, the concept of the graph induced from pessimistic multi-granulation rough set is presented, and the graph characteristic of its granularity reduction is given. On this basis, the significance of granularity is depicted by the method of graph, and then a algorithm about granularity reduction of pessimistic multi-granulation rough set based on graph is designed. Secondly, the concept of the graph induced from multi-granulation decision-theoretic rough set is defined, the graph characteristic of its granularity reduction and the significance of granularity are proposed at the same way, then a algorithm of granularity reduction of pessimistic multi-granulation decision-theoretic rough set based on graph is designed. Finally, it is rational to give an example to illustrate the pessimistic lower approximate multi-granulation rough set algorithm.