黑板框架的知识表达方法

Knowledge Representation Method of Blackboard Framework

本文介绍了黑板框架知识表达方法的设计思想和技术。黑板框架是由框架、知识源和黑板模型组成,是产生式规则、谓词、框架等多种知识表达功能的组合形式,它将知识表达和知识处理结合成一体,既能表达静态的知识,又能表达动态的知识;既能方便地表达断言性知识,又能自然地表达结构性知识。表达功能强、灵活性大;方便知识调度,加快推理速度,提高推理效率;方便知识获取并有利于机器学习。 黑板框架是一种能表达特定领域复杂知识结构的良好的方法,具有表达充分、推理充分、推理效率和获取效率高的特点。 文中还对目前各种知识表达方法进行了评价,对黑板模型、知识源、黑板框架的概念进行了描述,并对黑板框架给出了严格的BNF定义。 黑板框架的知识表达方法,已在医学专家系统开发工具BFBEST中获得了成功的应用,并取得满意的效果。

This paper introduces the idea of design and the technique of the knowledge representation method of blackboard framework. It consists of framework, knowledge sources and blackboard modules.It is a combined form of many knowledge representation methods,such as production rules, predicate calculus frame work, etc. It is a combination of knowledge representation and knowledge process,being used to represent both static and dynamic aspects of the application problem. Assertional knowledge and structural knowledge can easily be represented. It possesses a strong ability and flexibility. Knowledge may be easily scheduled to speed up inference,and new information may be easily acquired to benefit the machine learning.The blackboard framework is a good representation method for the complex structured knowledge in a parlicular domain. It possesses the good properties,such as representational adequacy,inferential adequacy,inferential efficiency,and acquisitional efficiency.This paper analyzes and evaluates the different kinds of representation methods, describes the concepts of blackboard model,knowledge source,and blackboard framework,and gives a rigorous BNF definition to the blackboard framework. The knowledge representation method of blackboard framework has been applied to the Blackboard Framework Based Expert System Tool (BFBEST) and the results are satisfactory.