基于动态描述逻辑DDL的动作理论

Action Theory Based on the Dynamic Description Logic DDL

基于一阶谓词逻辑或高阶逻辑的动作理论与采用命题语言的动作理论之间存在一个关于描述和推理能力的鸿沟;作为描述逻辑的动态扩展,动态描述逻辑DDL为基于描述逻辑的动作刻画和推理提供了一种途径。系统地研究了基于DDL的动作表示和推理问题。首先,在应用描述逻辑对静态领域知识进行刻画的基础上,引入带参数的原子动作定义式和带参数的复杂动作定义式,刻画出关于动作的知识;这两部分知识与关于具体状态的知识一起构成基于DDL的知识表示系统。接下来,针对该系统中刻画的各种知识,对相关推理问题进行了严格定义,给出了相应的推理机制和算法。最后探讨了基于DDL的动作理论在智能主体建模中的应用。基于DDL的动作理论既具有较强的知识表示能力,又提供了丰富的推理服务,适用于语义Web环境下对动作的刻画和推理。

There is a gap on expressive power and reasoning ability between the action theories which are based on first-or higher-order logics and the action theories which are only propositional.As a kind of dynamic extensions of description logics,the dynamic description logic DDL provides an approach for describing and reasoning about actions.An action theory based on DDL was presented and studied systematically.Firstly,based on a representation of static domain knowledge with description logics,the parameterized atomic action definitions and the parameterized complex action definitions were introduced for describing the knowledge of actions;both of these knowledge,and together with the know-ledge on the state of the world,are unified as a DDL-based knowledge representation system.Secondly,many reasoning tasks on the knowledge represented in this system were formally defined;corresponding reasoning mechanisms were also provided.Finally,the application of this action theory for the modeling of intelligent agents was discussed.The action theory based on DDL offers not only considerable expressive power but also attractive reasoning services;it is suitable for the description and reasoning of actions in the environment of the semantic Web.