基于Rough表达的时态关系代数  

Temporal relational algebra based on rough representation

作　　者：王路帮[1] 汤庸[1] 周风华[1] 

机构地区：[1]中山大学计算机科学系

出　　处：《计算机工程与设计》2005年第2期288-290,共3页Computer Engineering and Design

基　　金：国家自然科学基金项目(60205007)广州市重点科技基金项目(2002Z2-D3041)广东省跨世纪优秀人才基金项目(Q02095)。

摘　　要：现实世界的信息是和时间紧密相关的,因而记录和处理信息的数据库系统应该对时态问题进行考虑,以便更有效地解决现实问题;另一方面,现实世界的某些属性又很难用属性值简单描述。首先是用Rough理论对属性值进行一种刻画,用二元数组来表达属性值,并且将这种属性值的表达方式推广到一般情形,而后从时态映射的观点描述时态元组和时态关系,并由此形式描述相应的时态关系运算,从而建立了一套时态关系代数体系。The information of the real world is related greatly with time, so database system which registers and processes information should process the temporal problems, so that it can process real problem efficiently. At the same time, some attribute is hard to be expressed in simple attribute value in the real world. The attribute value is expressed in another way by rough theory, namely, representing the attributes through binary data. Then, the temporal tuple and temporal relation are described by temporal mapping, as well as temporal relational operation is described. At last, a new temporal relational algebra is established.

关 键 词：属性值 时态关系 元组 数组 数据库系统 形式描述 映射 代数 处理信息 现实问题 

分 类 号：TP311.12[自动化与计算机技术—计算机软件与理论] G633.62[自动化与计算机技术—计算机科学与技术]