基于证据理论的覆盖决策信息系统约简的数值刻画

Evidence-Theory-Based Numerical Characterization of Attribute Reduction in Covering Decision Information System

决策为划分的覆盖决策信息系统的特征选择理论和方法日趋成熟。但在数据采集的过程中,有些数据集存在对象的决策缺失或决策不能完全确定情况,那么将决策刻画为覆盖更加合理。而决策为覆盖的覆盖决策信息系统特征选择的研究却很少见。本文讨论决策为覆盖的覆盖决策信息系统的特征选择,利用证据理论中的信任函数和似然函数给出覆盖决策信息系统约简的等价刻画,从而给出求约简的算法,并以实例说明该方法的有效性。

The theory and methods of feature selection of the covering decision information system,whose decision is characterized by partition,are becoming mature. However,the decision attribute values of some objects in some data sets are missing or fuzzy. Then,it is reasonable to characterize the decision as a covering,but the study on feature selection of covering decision information system whose decision is characterized by covering is still very rare. In this paper,we discuss feature selection of covering decision information system whose decision is characterized by covering. We present a definition of attribute reduction in covering decision information system,and employ belief and plausibility functions from evidence theory to characterize the attribute reductions in covering decision information systems. Then,an attribute reduction algorithm based on evidence theory is proposed in covering decision information systems,and an example is used to illustrate the validity of the method.