Attribute Reduction Based on Equivalence Classes with Multiple Decision Values in Rough Set

摘要

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 is equal to the full region. Furthermore, if the attribute subset is independent and its indiscernibility relation is the same as the indiscernibility relation in original information system, then the subset is an attribute reduction of the information system. Finally, the experiment result demonstrates that our method is efficient.