基于多决策值等价类的属性约简

Attribute reduction based on equivalence classes with multiple decision values

针对决策信息系统属性约简问题,引入条件属性的多决策值等价类概念,给出实现属性约简的必要条件,提出一种基于多决策值等价类的属性约简算法。该算法以单个条件属性的等价类的基为升序,对条件属性进行排序,逐一选择排序后的条件属性合并,直至合并后的条件属性子集的正域为全域,进一步判断其是否独立且不可区分关系与原信息系统的不可区分关系是否相同。当条件满足时,该条件属性子集即为决策信息系统的属性约简。通过实例验证了该算法求解属性约简的有效性。

For the attribute reduction problem of decision information systems, the concept of the equivalence class only including the condition attributes is introduced. The necessary condition of implementing attribute reduction and the attribute reduction method based on the equivalence classes with the multiple decision values are presented. After sorting the condition attributes by the cardinalities of the equivalence classes with the multiple decision value in ascending order, these ordered condition attributes are united one by one until the positive region of the united attribute subset equal to the full region. Furthermore, when the in discernibility relation induced by the obtained attribute subset is the same as the indiscernibility relation in original information system and the attribute subset is independent, the subset is an attribute reduction of the information system. Finally, the expe rimental result demonstrates that our method is efficient.