决策系统中几种约简之间的关系

Relationships Between Several Reductions in Decision System

不可区分关系是粗糙集理论的基础。首先,刻画了λ约简与最大分布约简、分布约简之间的相互关系,证明了λ协调集是最大分布协调集,也是分布协调集;其次,针对λ约简设计了一种基于区分矩阵中属性频率的启发式约简算法,可以降低约简计算的复杂度;最后,通过实例验证了所提算法的可行性与有效性。

The indiscernibility relation is the basis of rough set theory.Firstly,this paper studied the relationship betweenλ-reduction,maximal distribution reduction and distribution reduction in decision table.It is proved that aλ-consistent set is a maximal distribution consistent set and a distribution consistent set.Secondly,this paper designed a heuristic reduction algorithm based on the attribute frequency in the distinguishing matrix forλ-reduction,which can reduce the complexity of reduction calculation.Finally,the feasibility and effectiveness of the proposed algorithm was verified by examples.