纺织专家系统中知识与知识库的应用

专家系统是人工智能的一个分支，是一种模拟专家决策能力的计算机系统，知识库是系统的重要组成部分，是系统的核心。本文结合纺织工艺设计及管理专家系统介绍了基于知识的专家系统的概念和结构，对系统中知识的获取、存储方式予以说明．并对其知识的表示方法加以阐述。     

Fuzzy expert system with double knowledge base for ultrasonic classification

This article shows a pattern recognition method for object classification using ultrasonic sensors and a dual knowledge base fuzzy expert system. The developed system uses a pair of ultrasonic sensors for obtaining information about the object shape from the ultrasonic echo signal envelope. In order to reduce the size of the database, a set of parameters is calculated for extracting knowledge about the object. However, the information provided by ultrasonic sensors contains a very high uncertainty level. This uncertainty is caused by several environmental effects, which are very difficult to eliminate in industrial applications. Among these environment factors are the air temperature and humidity, the air movement, etc. They create variations in the proprieties of the medium and disturbances during the acoustic propagation process. The presented system has been specially designed for industrial applications, where it is very difficult to reduce these disturbances and where it is necessary to use intelligent systems with high autonomy. The fuzzy expert system proposed has a dual knowledge base, that is, a statistical knowledge located on the memberships functions, and the standard rule-based knowledge. This expert system deals with the uncertainties in the information, and it is able to generate and modify the knowledge base and the decision rules in an automatic way. Furthermore, it is able to adapt the knowledge base to the slow changes produced by disturbing factors, such as humidity and temperature. On the other hand, because this system maintains a rule-based structure it is very easy to incorporate expert human knowledge.     

Constructing and consulting the knowledge base of an expert systems shell

Abstract: This paper presents an expert system shell whose inference mechanism uses backward chaining. In particular the modules devoted to constructing and consulting the knowledge base are illustrated. The programming environment is based on the Arity-Prolog language, a popular Prolog dialect running on IBM PCs and compatibles.     

基于模糊理论的造纸专家系统--知识库的设计

基于模糊理论的造纸专家系统(PMES)的研究对于保障设备的稳定运行,提高产品质量具有重要的意义.本文探讨了模糊理论在知识表示方面如何和专家系统进行有效地结合,并对PMES的知识库进行设计.对知识库采用知识分级的方式,使知识的表达更具有层次性.通过各个知识表中的相互约束关系保证知识的一致性.     

Development of an intelligent knowledge base for heat stress evaluation

An intelligent knowledge base system for heat stress evaluation is described. The evaluation of heat stress is a particularly difficult problem, utilizing a variety of sometimes contradictory heat stress indices, and thus is naturally suited for computer aided design. The present system uses an expert system approach and can be used either as a stand along design tool or as one of the lower level models for larger ergonomic expert systems such as ALFIE. Simulations of a variety of environmental conditions were performed. A large diversity in predictive capabilities was found, depending on the assumptions used for each component index. For maximum efficiency with novice users, further explanations and on-line assistance need to be implemented within the system.     

Development of an integrated expert system for fluvial hydrodynamics

During recent decades, rapid developments in computer science and industry have been influencing every aspect of our social life. Computer Aided Design (CAD) techniques have a significant impact in engineering fields. For fluvial engineering fields, a large number of microcomputer-based programs are applied for hydrodynamics analyses during the project design stage. Recently, achievements in Artificial Intelligence (AI) have been applied in many fields. The application of expert system techniques is an attractive trend in modern design practice. It is believed that the synthetic utilization of CAD and AI techniques would become more attractive for engineers. Yet the studies on this topic are scarce. This paper describes the architecture and implementation of an integrated expert system that assists hydraulic engineers to solve the unsteady open channel flow in river networks. A methodology of combining numerical analysis software into an expert system is presented. The verification, validation, application, and future development of this system are also presented.     

Development of an expert system advisor for anaesthetic control.

A review is given of numerous approaches which have been taken to provide automated control of depth of anaesthesia. Most of these approaches use a single indicator for anaesthetic state, and do not perform adequately for such a complex system. It is desirable, therefore, to merge a number of qualitative clinical signs and quantitative on-line measurements to provide decision-support for control of anaesthetic depth. The paper describes such an expert system called Resac (Real time Expert System for Advice and Control). Details of the knowledge representation and inference structure are given, together with the method adopted for propagating uncertainty measures, combining fuzzy information and merging quantitative and qualitative indicators. The importance of good human machine interface design is shown via the GEM-based graphics of Resac.     

Development of an expert system for optimizing natural gas pipeline operations

This paper presents an expert system as a decision support tool to optimize natural gas pipeline operations. A natural gas pipeline control system is a controlling system that involves many complicated operating processes. Since a dispatcher (who operates the system) might not be able to handle all of his or her tasks consistently, an expert system has been developed for optimizing the operations by providing consistent, fast and reliable decision support to the dispatcher. Consequently, inconsistency in the dispatcher's performance can be minimized. To build an expert system, the knowledge from an experienced dispatcher, who is familiar with the process in this controlling system is acquired and that knowledge has been implemented as rules in the knowledge base of the expert system. When this expert system has been validated by gas pipeline experts, it can help inexperienced dispatchers to operate the processes more effectively. The expert system is implemented on the real-time expert system shell G2 (trademark of Gensym Corp. of USA). The system also consists of a user interface that helps dispatchers visualize system conditions.     

A knowledge sorting process for a product design expert system

Knowledge sorting is one way to organize the knowledge acquired from the domain expert(s) and various sources. Well-organized knowledge representation will make rule extraction much easier. This paper describes a knowledge sorting process that was developed to facilitate the rule extraction for a product design expert system. The process capitalizes on the relationships between design attributes and factors, dependent and independent variables, and consists of three stages: identification of knowledge sources, generation of taxonomic trees, and organization of acquired knowledge. An example applies the sorting process to the development of an expert system for the design of wood head golf clubs.     

Implementation of knowledge maintenance modules in an expert system for fault diagnosis of chemical process operation

Based on the authors previous work of developing an expert system for fault diagnosis of chemical processes, this paper presents principles and approaches of the knowledge base maintenance in the expert system. Development and implementation of maintenance modules for the knowledge base in the expert system for fault diagnosis of fluid catalytic cracking unit (FCCU) are reported in detail. Algorithms are proposed for integrality verification of five inconsistencies among heuristic rules: contradiction, redundancy, subsumption, circulation, and reclusion. The modules ensure the knowledge base and the expert system to work stably and efficiently. DELPHI and SQL SERVER are adopted in developing the modules. Application in FCCU fault diagnosis expert system shows that the modules work rationally and efficiently with user-friendly interface, besides its strong interactive feature and better performance of the expert system. The modules have been in continuous use in the expert system of fault diagnosis of FCCU installation in a refinery for the last two years.     

A strategy of knowledge elicitation for developing an integrated bidding/production management expert system for the precast industry

Bidding and production decisions, including the estimation of optimal mark-up on price, represent major decision problems for companies formulating a successful business strategy. The objective of this research was to develop a strategy for developing an integrated bidding/production management expert system to assess the suitability of incoming enquiries for a particular company and suggests a ‘bid/no bid’ decision. If a decision to bid is taken then the expert system should provide advice on the optimal mark-up to maximise the chance of winning potential contracts. The system developed in this paper is composed of an information system, that integrates design, estimation and production planning, and a knowledge-base to provide abstracted information and advice to managers in charge of bidding. The information system analyses the records of previous contracts and presents managers with vital information that minimises the risk of poor decisions associated with bidding. The knowledge-base is composed of intelligent rules which were elicited from previous contract records and experienced managers in charge of bidding. They are designed to advise managers on two major issues: bid/no bid and estimation of optimal tender price. A number of factors that affect bidding strategies were identified from reviewing previous bidding methodologies and surveying eight major companies in the UK by means of semi-structured interviews.     

搅拌设备化工预设计专家系统的知识处理

详细论述了搅拌设备化工预设计专家系统的知识处理方法。系统采用黑板结构将多种知识源组合在一起来实现问题的求解,即采用基于规则的推理、基于模糊逻辑的模式匹配和传统的数据库查询等技术,来分别处理搅拌设备设计过程中的人类专家经验、设计公式和机械部件标准等不同种类的知识。此专家系统的结构和知识处理的方法具有较强的灵活性,非常适用于复杂的工业过程设计领域。     

搅拌设备化工预设计专家系统的知识处理

详细论述了搅拌设备化工预设计专家系统的知识处理方法。系统采用黑板结构将多种知识源组合在一起来实现问题的求解,即采和基于规则的推理、基于模糊逻辑的模式匹配和传统的数据库查询等技术,来分别处理搅拌设备设计过程中的人类专家经验、设计公式和机械部件标准等不同种类的知识。此专家系统的结构的知识处理的方法具有较强的灵活性,非常适用于复杂的工业过程设计领域。     

Multi-criteria scheduling: an agent-based approach for expert knowledge integration

In this work, we present an agent-based approach to multi-criteria combinatorial optimization. It allows to flexibly combine elementary heuristics that may be optimal for corresponding single-criterion problems. We optimize an instance of the scheduling problem 1|d _j |∑C _j ,L _max and show that the modular building block architecture of our optimization model and the distribution of acting entities enables the easy integration of problem specific expert knowledge. We present a universal mutation operator for combinatorial problem encodings that allows to construct certain solution strategies, such as advantageous sorting or known optimal sequencing procedures. In this way, it becomes possible to derive more complex heuristics from atomic local heuristics that are known to solve fractions of the complete problem. We show that we can approximate both single-criterion problems such as P _m |d _j |∑U _j as well as more challenging multi-criteria scheduling problems, like P _m ||C _max,∑C _j and P _m |d _j |C _max,∑C _j ,∑U _j . The latter problems are evaluated with extensive simulations comparing the standard multi-criteria evolutionary algorithm NSGA-2 and the new agent-based model.     

Development of an expert system for preliminary risk assessment of existing concrete dams

The paper presents an expert system to assist in the field inspection of existing concrete dams within the context of a preliminary risk assessment. The paper describes the engineering knowledge and reasoning required to conduct a deterministic field evaluation of the structural stability of the dam. The symptoms and failure modes identified by the expert system along with the required knowledge and procedures are organized in a structured knowledge tree. The instantiation of the frames and firing of the rules for each consultation traces part of the inference tree contained in the structured knowledge tree. Interaction between nearly decomposable problems are executed with metaknowledge procedures, shared rule groups, and active values. Examples are provided.     

Prototypical knowledge for expert systems

Knowledge of situations typically encountered in performing a task is an important and useful source of information for solving that task. This paper presents a system that uses a representation of prototypical knowledge to guide computer consultations, and to focus the application of production rules used to represent inferential knowledge in the domain. The explicit representation of control knowledge for each prototypical situation is also emphasized.     

A methodology for eliciting,modelling, and evaluating expert knowledge for an adaptive work-integrated learning system

We present a methodology for constructing and evaluating models for adaptive informal technology-enhanced workplace learning. It is designed for knowledge-intensive work domains which are not pre structured according to a fixed curriculum. We extend research on Competence-based Knowledge Space Theory which has been mainly applied in educational settings. Our approach employs systematic knowledge elicitation and practically feasible evaluation techniques performed as part of the modelling process for iterative refinement of the models. A case study was performed in the Requirements Engineering domain to apply and test the developed methodology. We discuss lessons learned and several implications for knowledge engineering for adaptive workplace learning.