Journal of Computer Applications ›› 2015, Vol. 35 ›› Issue (7): 1915-1920.

### Computing method of attribute granule structure of information system based on incremental computation

1. 1. College of Management, Northwestern Polytechnical University, Xi'an Shaanxi 710072, China;
2. School of Economics and Management, Xidian University, Xi'an Shaanxi 710071, China
• Received:2015-02-03 Revised:2015-03-23 Online:2015-07-10 Published:2015-07-17

### 基于增量计算的信息系统属性粒结构计算方法

1. 1. 西北工业大学 管理学院, 西安710072;
2. 西安电子科技大学 经济与管理学院, 西安 710071
• 通讯作者: 郝彦彬(1976-),男,黑龙江伊春人,讲师,博士研究生,CCF会员,主要研究方向:信息系统、数据挖掘、粒计算,nwpuhyb@163.com
• 作者简介:郭晓(1981-),女,山东泰安人,讲师,博士,主要研究方向:管理系统工程、风险管理、项目管理; 杨乃定(1964-),男,陕西户县人,教授,博士生导师,博士,主要研究方向:管理系统工程、风险管理、项目管理。
• 基金资助:

国家自然科学基金资助项目(71471146)。

Abstract:

A computational method utilizing divide-and-conquer and incremental computation was proposed to calculate the structure of attribute granule of an inseparable information system. Firstly, the rule that how the structure of attribute granule of an information system changed when new Functional Dependency (FD) was added to the functional dependency set of an information system was studied and the increment theorem of information system structure was proved. Secondly, by removing a part of the functional dependency, an inseparable information system could become a separable information system and the structure of the separable information system was calculated by using decomposition theorem. Thirdly, the removed functional dependency was added to the separable information system and the structure of the original information system was calculated by using increment theorem. Lastly, the algorithm to calculate the structure of attribute granule of inseparable information system was given and its complexity was analyzed. The complexity of the direct calculation of the structure of attribute granule of information system was O(n×m×2n), and the proposed method could reduce the complexity to below O(n×k×2n)(k<m), and when k=1,2, the complexity could be reduced to O(n1×m1×2n1)+O(n2×m2×2n2)(n=n1+n2,m=m1+m2). The theoretical analysis and practical calculation demonstrate that the proposed method can effectively reduce the computational complexity of the structure of attribute granule of an inseparable information system.

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