基于证据理论的覆盖决策信息系统的属性约简

Attribute Reduction of Covering Decision Information System Based on Evidence Theory

覆盖决策信息系统的属性约简是粗糙集理论中的重要研究内容之一.文中讨论决策为覆盖的覆盖决策信息系统的属性约简,针对覆盖决策信息系统的一类约简,利用证据理论中的信任函数和似然函数给出约简的等价刻画.根据决策类的似然函数值定义覆盖的重要度和相对重要度,给出求解约简的算法,并以实例说明算法的有效性.

The attribute reduction of covering decision information systems is one of the most important problems of the rough set theory. In this paper, the decisions of covering decision information systems are characterized by coverings, and attribute reductions of the covering decision information systems are explored. The belief and plausibility functions from the evidence theory are employed to characterize attribute reductions in the covering decision information system. By plausibility function values of decision classes, the definitions of significance and relative significance of coverings are also developed. Then, an attribute reduction algorithm based on the evidence theory is proposed in the covering decision information system, and an example is adopted to illustrate the validity of the propose algorithm.