Active databases react to stimulation, or event from inside or outside the system without user or application interference through Events Conditions Actions(ECA) rules (triggers). ECA rule is defined as: ON event IF c...Active databases react to stimulation, or event from inside or outside the system without user or application interference through Events Conditions Actions(ECA) rules (triggers). ECA rule is defined as: ON event IF condition THEN action, which means when an event happens, if the condition is satisfied then the corresponding action is executed. The nature of ECA rule makes it an appropriate means to model dynamic character of systems, as gained much studies during recent years. Traditional ECA rule is crisp, which means their events, condition (s) and action(s) are accurate. As indicate that ECA rules can only represent precise knowledge. But knowledge is usually fuzzy in engineering. A concept of fuzzy ECA rules characterized with fuzzy event, fuzzy condition and fuzzy action is proposed in this article.The realization avenues of fuzzy triggers are discussed. The work we have done blazes a way in representing approximate syntax in active database application systems. At last a case of 'overheating alarm' is given to illustrate the approach.展开更多
It is known as Coupling Modes that how the rule in active database system is triggered to ex-ecute by rule monitor when some special events occurs. In general, the Coupling Modes may be divided into immediate, deferre...It is known as Coupling Modes that how the rule in active database system is triggered to ex-ecute by rule monitor when some special events occurs. In general, the Coupling Modes may be divided into immediate, deferred and detached modes in active database systems. This paper clas-sifies the coupling modes into syn-coupling and asyn-coupling modes, according to the key issue, synchrony/asynchrony, in parallel programming language. Rule execution semantics for various coupling modes is distinctly defined. It is beneficial to implementation and usage of the active rule system. After graph-based rule system (E-RG) and its execution modei, which have been re-searched in their previous works, are chiefly described, the authors show the various strategies to construct the syn-coupling and asyn-coupling modes in E-RG rule system, based on semantics for coupling modes.展开更多
文摘Active databases react to stimulation, or event from inside or outside the system without user or application interference through Events Conditions Actions(ECA) rules (triggers). ECA rule is defined as: ON event IF condition THEN action, which means when an event happens, if the condition is satisfied then the corresponding action is executed. The nature of ECA rule makes it an appropriate means to model dynamic character of systems, as gained much studies during recent years. Traditional ECA rule is crisp, which means their events, condition (s) and action(s) are accurate. As indicate that ECA rules can only represent precise knowledge. But knowledge is usually fuzzy in engineering. A concept of fuzzy ECA rules characterized with fuzzy event, fuzzy condition and fuzzy action is proposed in this article.The realization avenues of fuzzy triggers are discussed. The work we have done blazes a way in representing approximate syntax in active database application systems. At last a case of 'overheating alarm' is given to illustrate the approach.
基金the National Natural Science Foundation of China(No.60073045)
文摘It is known as Coupling Modes that how the rule in active database system is triggered to ex-ecute by rule monitor when some special events occurs. In general, the Coupling Modes may be divided into immediate, deferred and detached modes in active database systems. This paper clas-sifies the coupling modes into syn-coupling and asyn-coupling modes, according to the key issue, synchrony/asynchrony, in parallel programming language. Rule execution semantics for various coupling modes is distinctly defined. It is beneficial to implementation and usage of the active rule system. After graph-based rule system (E-RG) and its execution modei, which have been re-searched in their previous works, are chiefly described, the authors show the various strategies to construct the syn-coupling and asyn-coupling modes in E-RG rule system, based on semantics for coupling modes.
