面向对象修改的核属性更新算法

Updating Algorithms of Core Attribute Based on Modifying Data

决策表中的对象被修改,核属性将会发生变化,需要对核属性及时更新。为此,首先,构造决策表等价类链表存储结构,并引入基于该存储结构的简化决策表定义和基于简化决策表的核属性定义;同时证明了该核属性与正区域核属性是等价的。然后,讨论修改指定对象情况下核属性更新方法,并给出相应的算法实现;算法以简化决策表为基础,仅需对等价类链部分搜寻,查找待修改对象,缩小了查找范围,提升了算法效率;另外,采用核属性计数方法,避免可分辨矩阵的存储,降低了空间复杂度。最后,通过实例验证了该算法的有效性。

In order to update the core attributes of decision table dynamically,when the decision table object is modified,the storage structure of equivalence class list table of decision table was constructed,and the definitions of the simplified decision table and core attributes based on the simplified decision table were proposed.It was proved that the core attributes acquired from the definition is equivalent to core attributes of positive region.And then,the theories of updating core attributes,which aims at the aspects of modified the object appointed,were researched.The corresponding algorithm was described,which on the base of simplified decision table,only needs to search the part of equivalence class list table to obtain the modifying object,reduces the search range and enhances the efficiency of the algorithm.The method of counting core attributes was used to avoid storing discerniblity matrix and reduce the space complexity.Finally,the validity of the algorithm was verified in instances.