The Formal Research On Assertion Elements Of Event Ontology

In the field of artificial intelligence, event as the basic unit of the knowledge representation, has received more and more attention by scholars. Now, most research on ontology is based on the static concepts or the relationship between the concepts. Although achieving good representation of the static knowledge system, it is unable to complete the dynamic knowledge representation. The world is changing every moment, so it’s not comprehensive enough to use static knowledge to represent the ontology model. Taking event as the research foundation, it’s closer to the objective world through starting from the characteristic of dynamic changes of the events to construct the event ontology model.Events are usually not isolated, can lead to a variety of results, can trigger other associated events. Assertion element one of the six elements of event ontology model, including pre assertion elements, elements of intermediate assertions and post assertions elements. Event pre assertion elements expressed state conditions to meet the event, as the trigger condition of the event. Event intermediate assertion elements represent a set of intermediate state. Event post assertion elements indicated a set of the result state after the events. Event assertion elements represent the dynamic change process of the event state. In this paper, the main research is to show a formal description of the assertion elements, and based on this, giving a study of the feasibility of the event state reasoning. The main contents include:(1) A formal method of extended Z language is proposed for event ontologyFirst, we introduce the event assertion elements and formal specification language, mainly analyzes the features of the Z language and the essence changing of the event state, put forward using the method of Z language as the basic language model to complete formal description of the event assertion elements. Then analyzes the events and the uncertainties of the events state changing, then we introduce fuzzy logic, try to combine Z language and fuzzy set, making the formal description more close to the objective reality. In this paper,through the examples show that the formal method is feasible.(2) Study on the event reasoning mechanism which based on the event assertion elementsFirst, according to the situation that event text has lack of relevant description of the event assertion elements. We give a method about fuzzy reasoning to make assertion elements complete. Then we introduce a method of assertion reasoning. Extended Hoare logic, this paper uses sequential reasoning rules to realize the sequential reasoning and the judgement of association strength between events. In this paper,through the examples verify that event reasoning method is feasible and effective, which is based on event assertion elements.