事件本体中的动作推理研究

Research on Action Reasoning in Event Ontology

事件是随时间变化而变化的具体事实,事件是由动作、时间及其它要素组成,动作是事件定义中的主要构成部分.在面向事件的知识库系统中,关于动作的推理研究一直是重要的研究课题之一.现有的动作推理形式化系统旨在描述和推理现实世界中状态的变化,忽略了时间要素对推理过程的影响.针对这种不足,本文在描述逻辑的基础上扩充了一个Action-TBox和一个Action-ABox,并将事件本体中的动作要素和时间要素相结合,形式化定义了动作的一个三元组表示方式以及多种时间构造算子,用以刻画组合动作的发生过程,在此基础上研究了事件本体中关于动作的几种推理服务.

Events are the specific facts which change over time. And they are comprised of actions, time and some other factors. But action is the main factor in the definition of event. Reasoning about action is always an important research topic in the event-based knowledge system. Current action formalisms aim at describing and reasoning about the status changing of real world, and neglect that the time of actions will change the reasoning process of action. In this paper, an Action-TBox and an Action-ABox axe proposed based on description logic, and a 3-tuple formal definition of action with temporal constructors is also introduced to the procedure of status changing for composite actions. Based on this formalism, several inference services of actions involved in event ontology are discussed, in which both the action and time are regarded as important factors that affect reasoning results.