分布式知识系统中基于粗糙集合的查询策略研究

详细信息

RESEARCH ON ROUGH SET BASED QUERY STRATEGY IN DISTRIBUTED KNOWLEDGE SYSTEM

1.
Dept. of Computer Science and Engineering, Southeast University, Nanjing 210096
2.
Dept. of Computer Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016

摘要: 传统数据库中的数据查询通常忽视了对于知识的应用．随着网结技术的发展，数据被分布在不同的物理节点上，用户已不太可能对所有数据均有全面的了解．本文讨论了分布式知识系统中基于粗糙集合的查询策略，强调了系统中知识的重要性．它可大大地降低网络节点间的通信代价，从而提高查询效率．粗糙集合理论的应用使得查询不必局限于传统的精确匹配式查询，而可以是一种粗糙、模糊匹配式的查询．
- 分布式知识系统 /
- 查询策略 /
- 粗糙集合
Abstract: It has usually ignored the usage of knowledge when querying data in a traditional database. By the rapid development of network, data are distributed to different physical sites. It is almost impossible for the users to know the data wholly in such complicated cases. In this paper, we present a rough set-based query strategy in a distributed knowledge system and concentrate on the role of knowledge. It can reduce the communication costs among the different sites of network, and enhance the query efficiency accordingly. Rough set theory makes the query rough or fuzzy, not being precise as in the conventional case.
- distributed knowledge system /
- query strategy /
- rough sets

[1]	王以和,涂小平.分布式数据库系统.电子工业出版社,1988
[2]	Z W Ras. Collaboration Control in Distributed KnowledgeBased Systems. Information Sciences Journal,1997,96(3/4):193～205
[3]	Z W Ras. Handling Queries in Incomplete CKBS through Knowledge Discovery. In:Proceedings of Rough Sets and Current Trends in Computing'98,Springer Verlag,1998,194～201
[4]	Z Pawlak. Rough Sets-theoretical Aspects of Reasoning about Data. Kluwer Academic Publishers,1991
[5]	J W Grzymala-busse. Managing Uncertainty in Expert Systems.Kluwer Academic Publishers,1991
[6]	A Hrn. ROSETTA Technical Reference Manual:[Research Report]. Knowledge Systems Group,Norwegian University of Science and Technology,Trondheim,Norway,1998
[7]	Z F Ma,H C Xing,X M Zheng. A Multi-tuple Rough Set Approach for Information Retrieval. Journal of Southeast University (English Edition),1999,15(1):61～66
[8]	马志锋,邢汉承,郑晓妹.决策表中规则获取的不确定性研究.控制与决策,2000,15(6)
[9]	马志锋,邢汉承,郑晓妹.不完整Vague决策表中的近似集学习方法.计算机研究与发展,2000,37(9):1050～1057
[10]	X Hu,N Cercone. Learning in Relational Databases:a Rough Set Approach. Computational Intelligence,1995,11 (2):323～338
[11]	马志锋,邢汉承,郑晓妹.基于不分明与相似关系的Rough集的超图描述.计算机科学,1999,26(9):35～39