In this paper,based on probabilistic and cognitive uncertainties,we set up an uncertain database model and presented the uncertain relational algebra ,and proved that the uncertain normal forms are closed under operat...In this paper,based on probabilistic and cognitive uncertainties,we set up an uncertain database model and presented the uncertain relational algebra ,and proved that the uncertain normal forms are closed under operations of the uncertain relational algebra. At last ,we studied the semantics of the uncertain relation.展开更多
针对不确定的传感器数据流,在对国外数据流管理原型系统研究的基础上,采用客户机/服务器体系结构,在Red Hat Linux 9.0平台上部分地实现了不确定数据流数据库系统(UCDS)。详细描述了不确定数据流数据库系统的基本定义、系统的体系结构等...针对不确定的传感器数据流,在对国外数据流管理原型系统研究的基础上,采用客户机/服务器体系结构,在Red Hat Linux 9.0平台上部分地实现了不确定数据流数据库系统(UCDS)。详细描述了不确定数据流数据库系统的基本定义、系统的体系结构等,为不确定性数据库的研究做出了有益的探索。展开更多
文摘In this paper,based on probabilistic and cognitive uncertainties,we set up an uncertain database model and presented the uncertain relational algebra ,and proved that the uncertain normal forms are closed under operations of the uncertain relational algebra. At last ,we studied the semantics of the uncertain relation.