中文摘要：

文本事件的表示一直缺乏针对事件要素的有效表示和推理方法,采用传统描述逻辑对基于事件的知识进行形式化表示存在表达能力不足的问题.提出一种新的事件本体结构模型,在此基础上对描述逻辑的子语言SROIQ进行扩展,同时提出事件要素投影理论实现对事件本体的形式化.该方法利用SROIQ丰富的表达能力,将动态的事件转换为静态的复杂概念,既统一了事件与事件状态的表示方法,也建立起了事件之间、事件要素之间的语义关系.基于SROIQ的事件要素投影方法能够有效表示各领域的事件类、事件实例与事件要素,提取事件、事件关系在事件要素上的普遍规律,有助于领域事件本体的构建和形式化,以及针对事件要素的推理.

英文摘要：

Compared with traditional concept,event as a knowledge unit has numerous advantages in terms of knowledge representation.An event consists of a variety of elements including action,object,time and place,etc.But the complexity of event structure brings about difficulties on formalization and inference on events.Due to the lack of effective methods of representation and reasoning for the event elements in text,and the deficiencies of traditional description logic expression on event knowledge,an event element projection is proposed as a new formalization method.By means of powerful expression of extended description logic sublanguage,SROIQ,and based on a new event ontology model,this method has many advantages.Event element projection unifies representation of events and event status,and builds the semantic relations between events and elements.Based on SROIQ,event element projection is able to effectively represent event class,event instances and event elements in all areas,and to abstract the universal elemental features of events or event relations.It also contributes to the construction of domain event ontology and reasoning on event elements.An example of formalization on water pollution emergencies ontology is provided based on SROIQ and element projection method.The general process and steps of event ontology formalization areproposed as well.The semantics of event relations based on element projection and reasoning on event relations are also discussed at last.Event element projection makes element inference compatible with event class inference,simplifies syntax of formalization framework,and enriches the semantic definitions of various event relations.Based on this method and SROIQ,the expression of formalization framework could be enhanced and the reasoning ability could be ensured.