摘要
为了解决时态数据库对客观世界更符合实际的抽象描述、能有效表示和处理复杂对象、支持用户定义的数据类型、扩展建模能力、减少不同类型数据转换代价大等问题,针对复杂数据不仅有时态性,而且具有模糊的特性,从基本的时态数据库模型入手,定义了一系列模糊时态关系元素,并建立了一个能描述模糊时态信息的1NF关系代数.从理论上论证了相应的模糊/时态关系代数映射及运算模型,避免了模糊时态数据库不能提供表达时态信息的环境设施,也增强了现有时态数据库描述模糊事物特性的能力.
To bring further the abstract description provided by temporal database in accord with the actually objective world so as to express and deal with complex objects efficiently and support user-defined data types, with the modeling capability extended to reduce the cost due to the conversion of different types of data, a kind of INF （first normal form） relational algebra available to describe fuzzy temporal information is established by defining a series of fuzzy temporal elements via analyzing the basic temporal database model because the complex data are not only temporal but aim fuzzy. The relevant mapping operation model of the fuzzy temporal relational algebra is theoretically demonstrated, thus avoiding the flow that the fuzzy temporal database is unable to provide the ambient facilities to express temporal information and enhancing the capability of existing temporal database to describe the characteristics of fuzzy matters.
出处
《东北大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2008年第10期1414-1417,1430,共5页
Journal of Northeastern University(Natural Science)
基金
教育部新世纪优秀人才支持计划项目(NCET-05-0288)
关键词
时态数据库
关系代数
模糊数据库
模糊时态
一范式
temporal database
relational algebraic
fuzzy database
fuzzy temporality
1NF（first normal form）
