面向对象修改的核属性更新算法

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。

Updating Algorithms of Core Attribute Based on Modifying Data

It is necessary that the core attributes of decision table will be updated dynamically, when the decision table object is modified. In order to improve the efficiency of computing core attribute and be beneficial to the large data sets, the storage structure of equivalence class list table of decision table is constructed, and the definitions of the simplified decision table and core attributes based on the simplified decision table are proposed. It is proved that the core attributes acquired from the definition is equivalence to core attributes of positive region. And then, the theories and algorithms of updating core attribute are researched and described on the aspects of modified the object appointed. Finally, the validity of the algorithms is verified in instances.