知识工程中的知识库、本体与专家系统

随着语义Web思想的兴起,对专家系统的互操作性和共享性也提出了更高的要求,对新型知识表示方式和新型知识系统的研究是大势所趋.本体作为共享概念模型的明确的形式化规范说明,为不同系统之间的互操作提供了基本的框架,是解决共享和互操作问题的有效的方法.一些初学者对知识库、本体以及专家系统的概念产生了各种疑惑,根据笔者的理解与实践,对知识工程中的本体、知识库以及专家系统做出较系统的比较分析,对这几个术语做一个澄清.     

Ontological emergence scheme in self-organized and emerging systems

This paper presents the concept of “Ontological Emergence”, a process that seeks to adapt an ontology to the changes and new components in a self-organized and emergent system, through the application of a set of rules that allows the emergence of a new conceptualization (emerging concepts). The Ontological Emergence provides the structuration of the information and knowledge that could be generated in the system, creating conceptual models that can adequately represent the new behavior that is emerging. It arises from the need to represent ontologically a conceptualization of a reality that is dynamic, which cannot be pre-defined or pre-determined, in order to generate emerging knowledge models that follows the scalability and the evolution of it. In that sense, in this paper is proposed an “Ontological Emergence Scheme” based on a set of processes of registration, monitoring, analysis and adaptation of the various conceptual models that interact in the system, as well as on some processing rules in regard to requirements and information of the context, in order to allow the ontological emergence. In this proposal scheme, the Meta-ontologies guide the ontological emergence process through the definition of general categories, to facilitate the integration of concepts from different ontologies or data sources. Finally, the paper presents some case studies, showing its utility in self-organized and emergent systems.     

基于本体的故障诊断知识库系统的构建

传统故障诊断技术采用专家系统的知识库是封闭的或半封闭的,其知识库的构造和知识的输入与修改均需由设计者来进行,不能从故障诊断的成功经验中提取相关的知识。本体作为知识的基本元素,可以进行知识类比推理,抽象出事物内在的本质,适合于描述知识库的内部单元。提出一种基于本体的故障诊断知识库系统模型,并依据该模型设计了故障诊断专家系统。     

基于本体的应急救援知识库构建及其应用

针对专家系统在应急救援领域应用中存在的知识表示及推理等问题,采用基于本体的知识表示方法与基于Jena的规则推理引擎,参考简单知识工程方法论与Jena规则语法建立一个高速公路应急救援本体与推理规则,实现本体知识库的推理。将该知识库应用于高速公路应急救援系统中,结果表明其具备解决实际问题的能力;有利于领域知识的共享与重用;促进了专家系统在高速公路应急救援领域的发展。     

计算机本体理论在石油勘探开发知识管理系统中的应用研究

本体论与各个领域计算机技术的发展结合产生了所谓的“领域本体”的构建及应用研究, 首先介绍了计算机本体理论的基本概念, 接着给出石油勘探开发知识管理系统的框架设计, 然后提出基于多层次业务流程的石油勘探和开发领域知识本体库的构建方法, 把石油勘探开发领域所涉及方面分为多级业务活动层次, 并以采油工程方案为例列出了对应的知识本体库构建方法的探讨.     

基于知识工程的船体焊接工艺研究

船舶制造过程中船体焊接领域工艺知识缺乏有效的归纳与整理,导致其重用性和 共享性差。针对上述问题,基于知识工程技术,研究了船体焊接工艺领域知识的获取、分类、 表示及推理应用的方法,并开发了工艺知识库系统,有效实现了知识的共享与重用。首先提出 了船体焊接工艺知识获取途径及分类模式;其次以此为基础,将基于本体的知识表示方法的研 究成果应用于船体焊接工艺,建立领域本体;然后提出焊接工艺推理模式,以国家标准、行业 标准等规范性文件和专业书籍、专家意见等指导性文件为基础构建工艺规则库,设计模糊规则 推理系统;最终设计开发面向船体焊接工艺的知识库系统,规范化实现知识获取、知识表示、 知识推理及知识管理功能,为船体焊接领域相关工作人员提供知识共享及重用的支撑平台,为 船舶制造其他领域中知识工程技术的利用提供参考。     

A function-centered framework for reasoning about system failure at multiple levels of abstraction

This paper presents the knowledge organization for a simulation subsystem that is a component of a comprehensive expert system for failure modes and effects analysis. Organizing the simulation subsystem's knowledge base around a function-centered ontology produces an architecture that facilitates reasoning about an engineering design at multiple levels of abstraction and throughout the life-cycle of the design. Moreover, the resulting architecture provides the capability for incorporating computer-aided analysis and design tools early on into the conceptual design of an engineering system before a commitment is made to a specific technology to implement the system's behavior. The result is an expert system simulation knowledge source that can be used to reason about the effects of system failures based on conceptual designs, i.e. designs in which commitments to an underlying technology to achieve the system's function have not yet been made but computer-aided assistance for reasoning about the system's potential failure modes and effects is useful.     

基于本体知识库构建方法探讨

研究利用本体进行构建某一特定领域的知识库,这项技术被人们广泛地用于解决异构环境互操作、系统工程,以及通信等领域中的知识获取、知识共享、知识重用和系统集成等。在已有研究的基础上,将电动工具工业设计作为本体,归纳总结了某一具体领域本体知识库的构建方法,有助于前期调研人员更好地搜索准确有用的资料,也有助于设计人员高效并高质量地进行新产品开发,用途广阔。     

Collection, storage and application of human knowledge in expert system development

Abstract: Expert systems are programs that analyze data by mimicking the thought processes of an expert. Two expert systems were developed by the Reservoir Evaluation and Advanced Computational Techniques group to aid in oil prospecting for two New Mexico formations, leading to the development of a third customizable fuzzy expert system. Knowledge engineering is a major part of the development of these expert systems, in which expert knowledge is solicited, analyzed, converted to rules stored in a system's knowledge base, and used by the computer to produce expert judgment. Numerical versions of the rules are used to analyze data and produce an evaluation of the user's prospect. In addition, the knowledge base preserves expert knowledge for future workers. This is especially important in the petroleum industry, as there is a cyclical trend in employment relating to the price of oil, retirements and people leaving and entering the industry.     

本体知识库的模块与保守扩充

模块化是软件工程的一种方法,近年来被引入到本体领域,用以支持本体的重用和本体的整合。已有的工作没有讨论同时含有TBox和ABox的本体知识库的模块化的相关问题。在定义本体知识库的模块和知识库的保守扩充的基础之上,给出了知识库保守扩充的验证算法,并且从理论上证明可用知识库的保守扩充的验证算法来验证一个知识库是否为另外一个知识库的模块。     

故障诊断专家系统中知识库组织和维护技术的研究

在开发化工过程实时故障诊断专家系统的基础上,本文讨论了知识库的组织和维护技术,对知识表示和知识库结构进行了详细介绍。在知识库维护方面,采用面向对象的方法描述领域知识,并实现知识获取和转换;对于知识校验,提出一种基于有向图的知识校验方法。以润滑油生产过程为例,讨论了系统的知识校验过程。本文讨论的技术和策略已应用于润滑油过程实时故障诊断专家系统。实际应用表明,该技术和策略保证了知识库和专家系统的稳定和高效率。     

飞机故障知识的本体建模及语义检索

针对目前飞机维修保障工作中故障知识共享应用的实际困难,对飞机故障知识的表达建模以及检索应用进行了研究。依据飞机故障知识的领域特性和共享需求,采用本体作为知识表示的方法。根据本体组成元素分析了飞机故障本体的知识来源,并提出了飞机故障知识的本体工程构建方法。在本体模型的基础上,研究了飞机故障知识的语义检索模型,基于最近相邻检索策略提出了飞机故障本体的语义检索相似匹配算法及其实现流程。开发飞机故障知识管理原型系统并在某航空制造企业进行应用验证。     

基于本体和CBR的钻井工程风险决策模型研究

为了实现钻井工程风险智能决策,从钻井专家决策过程的特征出发,针对传统的CBR技术的不足,提出并构建了一种基于本体和CBR的钻井工程风险决策模型。通过对风险决策案例的分析,设计了钻井风险决策案例的结构,并结合本体技术构建了风险决策案例本体,使案例表示更规范化、语义化,同时为案例知识提供了良好的可扩展性与共享性;为了提高案例检索效率,按照本体中风险的类别对案例进行分层组织,建立了风险案例库;针对现有的案例相似度计算模型的缺陷,提出了一种改进的基于本体的语义相似度计算模型,并由此构建了风险案例检索模型,经现场实例测试,结果表明该模型有效地提高了案例检索的查准率和查全率。在以上基础上,开发了钻井工程风险决策原型系统,为钻井专家、技术人员提供了高效的决策支持。     

面向文本的本体学习研究概述

对本体（ontology）的研究在计算机领域变得越来越广泛,但手工构造本体是一项繁琐而辛苦的任务,还会导致知识获取瓶颈。本体学习技术是利用本体工程技术和机器学习技术等众多学科技术来实现本体的（半）自动构建。本体的学习可以面向文本、知识库、结构化数据、半结构化数据和无结构数据。本文主要介绍了面向文本的本体学习,并对其中的学习内容、学习方法、学习工具、学习过程和系统评价等关键技术进行了说明,特别介绍了学习方法中的基于统计的方法、词汇句法模式法和形式概念分析法并对其优缺点做了简单的分析。     

化工过程实时故障诊断专家系统的研究与开发

讨论了复杂化工过程实时故障诊断专家系统的设计与实现。对于该系统的系统结构、知识库结构以及推理机的设计进行了详细介绍。尤其是讨论了一种新的知识规则冲突消解策略——前提排序策略以及内存知识库中知识规则选择策略。并以润滑油生产过程为例,讨论了系统的故障诊断过程。实际应用表明,该系统能够及时、迅速地对故障做出响应,满足了生产需求。     

Ontology-based feature mapping and verification between CAD systems

Data interoperability between computer-aided design (CAD) systems remains a major obstacle in the information integration and exchange in a collaborative engineering environment. The use of CAD data exchange standards causes the loss of design intent such as construction history, features, parameters, and constraints, whereas existing research on feature-based data exchange only focuses on class-level feature definitions and does not support instance-level verification, which causes ambiguity in data exchange. In this paper, a hybrid ontology approach is proposed to allow for the full exchange of both feature definition semantics and geometric construction data. A shared base ontology is used to convey the most fundamental elements of CAD systems for geometry and topology, which is to both maximize flexibility and minimize information loss. A three-branch hybrid CAD feature model that includes feature operation information at the boundary representation level is constructed. Instance-level feature information in the form of the base ontology is then translated to local ontologies of individual CAD systems during the rule-based mapping and verification process. A combination of the Ontology Web Language (OWL) and Semantic Web Rule Language (SWRL) is used to represent feature classes and properties and automatically classify them by a reasoner in the target system, which requires no knowledge about the source system.     

本体知识库系统研究

该文在传统知识库系统的基础上,将本体论引入到知识库中。介绍了本体的起源及其在知识工程领域的发展,探讨了知识库系统中本体的定义和主要作用。然后,研究了知识库系统的构建方法,并以试题知识库系统为例介绍了它的应用。     

基于混合推理的知识库的构建及其应用研究

该文提出了基于OWL本体与Prolog规则的平面几何知识库的构建方法,从而可形式化地表示平面几何中丰富的语义信息.一方面,用类型、定义域、值域、分类、属性、实例等本体描述来表达结构化的知识,为领域内概念与概念之间关系的描述提供形式化的语义;另一方面,用Prolog规则来解决本体不能有效表达的诸如属性之间的关系和操作等问题,从而支持复杂关系间的推理.在此基础上,用Protégé和Prolog构建了一个基于本体和规则的平面几何知识库.实验证明:此知识库可实现知识和语义层次上的信息查询,还可进行复杂问题求解,其丰富的语义描述和混合推理能力弥补了传统知识库的不足.     

ExperTAXsm: an expert system for corporate tax planing

Abstract: This paper describes the development of ExperTAX^sm, an expert system designed as a part of the service rendered by the audit and tax practices of the accounting firm of Coopers & Lybrand in the corporate tax accrual and planning function. The current operating environment is described and the expert system based solution is presented. The knowledge engineering process is described in detail and novel techniques for knowledge extraction are presented. The resulting system and its knowledge base is also presented together with a discussion on detailed knowledge acquisition and ongoing knowledge base maintenance facilities.