不完备信息系统中Rough集的扩充模型-CiteSeerX.PDF

* 不完备信息系统中Rough 集的扩充模型 1 2 尹旭日 ，商琳 （1. 解放军汽车管理学院军交仿真实验室，蚌埠，233011； 2. 南京大学计算机软件新技术国家重点实验室，南京，210093 ） 摘要：经典的 Rough 集理论所处理的信息系统必须是完备的。为了能够分析处理不完备的 信息系统，需要建立新的扩充 Rough 集模型。对现有的几种比较有影响的 Rough 集扩展模 型进行了分析研究，提出了一种带约束的相似关系 Rough 集模型，并将这些扩充模型之间 的关系进行了分析比较。结果显示，基于约束相似关系的扩充 Rough 集模型优于基于容差 关系的扩充 Rough 集模型和基于相似关系的扩充 Rough 集模型，使得对象的划分更加合理， 符合人们在处理数据时的直观感觉。 关键词：Rough 集，不完备信息系统，容差关系，相似关系，约束相似关系 中图分类号：TP18 , Extension Model of Rough Set Under Incomplete Information 1 2 Yin Xuri ，Shang Lin (1. Simulation Laboratory of Military Traffic, Institute of Automobile Management of PLA, Bengbu, 233011,China ； 2. State Key Laboratory for Novel Software Technology, Nanjing University, Nanjing, 210093,China) Abstract ：The classical rough set theory is based on complete information systems. The starting point of the rough sets theory is an observation that objects having the same description are indiscernible with respect to the available information. It classifies objects using upper-approximation and lower-approximation defined on an indiscernibility relation that is a kind of equivalent relation. But the indiscernibility relation may be too rigid in some situations. Therefore several generalizations of the rough sets theory have been proposed. Some of them extend the indiscernibility relation using more general similarity or tolerance relations. For example, Kryszkiewicz has studied the tolerance relation, and Ste