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
A kind of classification on temporal relations of propositions is presented.By introducing temporal approaching relation, a new temporal logic based ontime-point and time-interval is proposed, which can describe uncer...A kind of classification on temporal relations of propositions is presented.By introducing temporal approaching relation, a new temporal logic based ontime-point and time-interval is proposed, which can describe uncertain temporalrelations. Finally some properties of temporal proposition under.uncertainrelations are proposed.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.
文摘A kind of classification on temporal relations of propositions is presented.By introducing temporal approaching relation, a new temporal logic based ontime-point and time-interval is proposed, which can describe uncertain temporalrelations. Finally some properties of temporal proposition under.uncertainrelations are proposed.
