基于信息量的悲观多粒度粗糙集粒度约简  

The granularity reduction of pessimistic multi-granulation rough set based on the information quantity

作　　者：孟慧丽[1,2] 马媛媛[1,2] 徐久成 

机构地区：[1]河南师范大学计算机与信息工程学院,新乡453007 [2]河南省高校计算智能与数据挖掘工程技术研究中心,新乡453007

出　　处：《南京大学学报（自然科学版）》2015年第2期343-348,共6页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(60873104;61370169);河南省科技攻关重点项目(112102210194);河南省教育厅自然科学研究项目(2011A520054)

摘　　要：多粒度粗糙集是目前粗糙集理论研究的一个新的方向,粒度约简是多粒度粗糙集研究的重要内容之一.首先将信息量引入悲观多粒度粗糙集的下近似分布约简,定义了悲观多粒度粗糙集下近似分布约简中粒度集的信息量.其次基于信息量定义了粒度的重要度,以粒度的重要度作为启发信息,设计了基于信息量的悲观多粒度粗糙集启发式粒度约简算法,通过实例验证了算法的有效性,为多粒度空间下粗糙集的粒度约简提供了理论依据.Rough set theory is a useful method which can effectively deal with imprecise and uncertain information in the information system.Granular computing is a new field of artificial intelligence and multiple granulation is a core concept of granular computing.Multi-granulation rough set is a new research direction of rough set theory,which combined with rough set theory and the idea of granular computing.In the view of granular computing,an equivalence relation is a granulation which composed of several attributes,and a partition of the universe based on a equivalence relation can be regarded as a granularity space.Hence in the multi-granulation rough set,based on different equivalence relations,the universe can be divided into several granularity spaces and the approximation of target concept can be carried out from the multiple granularity spaces.Granularity reduction is one of the important tasks of the multi-granulation rough set research.It is the deletion of unnecessary granularity under the premise of no affection to the target concept or decision rules.Information quantity is introduced into the lower-approximate distribution reduction of pessimistic multi-granulation rough set and the information quantity of a granularity has been defined in the lower-approximate distribution reduction of pessimistic multi-granulation rough set.Then,based on the information quantity,the importance of a granularity has also been defined.A heuristic granularity reduction algorithm ofpessimistic multi-granulation rough set is presented.The experimental results show the validity of the algorithm,which provides a theoretical basis for the granularity reduction of multi-granulation rough sets.

关 键 词：信息量 悲观多粒度粗糙集 粒度约简 

分 类 号：TP18[自动化与计算机技术—控制理论与控制工程]