An expert system that performs a satellite stationkeeping maneuver

The development and capabilities of a prototype expert system that provides real-time spacecraft system analysis and command generation are described. At present, ESSOC (Expert System for Satellite Orbit Control) is capable of performing the stationkeeping maneuver for a geostationary satellite. ESSOC guides the operator through the stationkeeping operation by recommending appropriate commands that reflect both the changing spacecraft condition and previous procedural action. Information regarding satellite status is stored in a knowledge base internal to the expert system. This knowledge base is continuously updated with processed spacecraft telemetry. Information on the procedural structure is encoded in production rules. The independence of the procedural rules from each other, and from the knowledge base, makes the system easy to maintain and expand. Particular attention is directed to distinctive features of the ESSOC system and its development, namely, the structured methods of knowledge acquisition, and the design and performance-enhancing techniques that enable ESSOC to operate in a real-time environment.     

Analog integrated filter compilation

A review of the progress in automated design of analog integrated filters is presented. Such tools are ahead of other analog circuit automation in terms of the acceptance by designers and practical applicability. A survey of the present-day commercial and academic systems is made and the range of facilities available is compared. The problems faced in the design of this type of software are typical of the problems of analog design systems in general; lack of openness for introduction of new design knowledge, difficulties of dealing simultaneously with expert and novice users, poor integration in design environments, and user-interface problems. The structure of a typical system is studied and the computer methods used within are discussed with regard to such issues as speed, flexibility, and ease-of-use. Some future directions for analog filter compilers are proposed.     

Remote Control of Automation Systems for DES Courses

The objective of technical courses is the transfer of knowledge and know-how to students. In the case of discrete event system courses, it is important for a learner to locally or remotely control real systems (or plants) that are composed of many sensors and actuators. The use of these devices poses several problems. First, it is difficult to adapt them to the student's level (from beginner to expert). Second, these systems are generally designed with industrial components. An error on the control-command design can involve safety problems and breakdowns. In this paper, the authors propose an original solution to solve these two problems. To guarantee the safety of the operators and the equipment, an approach using a validation filter is proposed. It is based on the definition of logical constraints, which should in no case be violated. To adapt the difficulty level, it is proposed to modify the level of automation. For that, the functional dimension of the automation system is modified to adapt the student's level of autonomy. The level of automation is defined by the teacher by means of a functional analysis of the system. To validate the approach, it is applied to an original project with ten-year-old children on a packaging system. The aim of the project is to enable ldquoyoung novice control engineersrdquo to perform their first programmable logic controller program to control the whole system.     

Automating reuse of software for expert system analysis of remotesensing data

Systems involving remote sensing analysis for airborne and satellite data in combination with geographic information systems are large and complex. The Canada Centre for Remote Sensing (CCRS) has created an expert system shell and several expert systems in order to provide image analysis programs with the necessary knowledge to solve difficult image processing problems, such as updating a forest inventory geographic information system. An interactive task interface (ILTI) provides an expert system with a Prolog module designed to answer queries from the image analysis program by retrieving knowledge from an image analysis knowledge base, the analyst advisor. Image analysis experts currently create ILTI's. They have found this to be a time-consuming task. An incremental/adaptive planner has been developed that will create a plan that emulates the ILTI's behavior by analyzing image processing session dialogues between a human expert and an image analysis program for several cases of forest updates. The planner relies on a knowledge base in order to generalize and modify plans acquired from session dialogues. The planner speeds and simplifies the creation of new expert systems     

固井专家系统设计探讨

通过分析固井专家系统的架构、业务流程和专家知识库的设计,涉及到固井施工设计及其优化、施工监控和远程会诊问题。通过该系统解决了专家脱离现场与现场迫切需要专家的矛盾,实现现场工程技术人员就能实时得到“专家”的指导和帮助。     

A Semiautomatic Approach to Deriving Turbine Generator Diagnostic Knowledge

Condition monitoring of turbine generators, housed at British Energy nuclear power stations throughout the U.K., is implemented to diagnose incipient faults at an early stage, so corrective action can be taken to avoid the associated high costs of an unplanned shutdown. A prototype expert system has been developed that provides decision support to condition monitoring experts who monitor British Energy turbine generators. The expert system automatically interprets data from strategically positioned sensors and transducers on the turbine generator by applying expert knowledge in the form of heuristic rules. This paper reviews the application domain and describes the work undertaken in developing the prototype expert system. The paper also outlines a learning module design that uses an approach based on an analytical symbolic machine learning technique, explanation-based generalization, to semiautomatically derive heuristic rules for turbine generator fault diagnosis. The approach adopted by the learning module is explained in detail and a worked example demonstrates how the learning module can derive a fault heuristic from a single training example. The modular approach to capturing the causal fault and behavioral models is described, and the method in which the module will be integrated with the existing expert system has been outlined. A preliminary evaluation of the learning module design is discussed.     

机械产品智能概念设计专家系统的研究与开发

通过总结专家进行概念设计的设计方式，分析了人工智能解决问题的方法，提出了智能概念设计专家系统的一种模式。应用这一模式，构造了简单机械产品智能概念设计专家系统并得以实现。     

Expert systems and telecommunications

First there were databases and database management systems. Then information bases developed, whereby management information systems and decision support systems sprouted. Now, there are knowledge bases on which expert systems are being built. The age of “knowledge” is upon us, and computer programs are being developed to perserve this knowledge. These computer programs are “expert systems” which mimic the behavior of human experts in some specified domain of knowledge. This article addresses these expert systems and gives some applications in the telecommunications area.     

基于神经网络专家系统的推理研究

为了克服传统专家系统知识获取难、学习适应能力差、推理效率低等问题,许多专家提出将神经网络与规则专家系统相结合,构建基于神经网络的专家系统模型。文中设计了一种基于神经网络专家系统模型的混合推理机制,通过对基于神经网络推理算法、规则推理算法以及神经网络与规则的混合推理算法进行实验比较,证明本文提出的混合推理机制在改善专家系统推理准确率方面的有效性。     

Artificial intelligence in power system operations

Power system operators often reach a cognitive barrier when information arrives too fast during a power system emergency. At such times it becomes difficult to reach a correct diagnosis of the problem or to formulate the correct decision when actions must be taken. Artificial Intelligence gives designers of Energy Management Systems a way to solve many of the diagnosis and decision problems so as to make the EMS more useful. This paper explores reasons why AI techniques, such as knowledge-based expert systems, are being used in EMS designs and the differences between knowledge-based expert systems and traditional numeric algorithm development. The differences between expert systems and the numeric approach extend to the basic conception and design of the applications. This is illustrated using a relay fault diagnosis system, showing both the traditional and rapid prototyping approaches to its development. Finally, issues concerned with the implementation of AI in EMS computers are explored along with the authors' predictions of possible AI applications to power system operations.     

浅谈Auto CAD 在LCD中的应用

详述最新版计算机辅助设计软件Auto CAD2000在液晶显示器制作过程掩 膜版设计中的应用。根据实际设计经验，介绍使用该软件的方法和技七，给出Auto CAD在生产液晶显示器过程曝光用掩膜版设计中所需要的各种相关命令。     

基于模糊理论的地下水质量诊断专家系统研究与设计

如何有效地对地下水质量进行监测和评价,正成为环境研究领域中一项十分活跃的研究课题。针对这个问题,设计了一个地下水质量模糊诊断专家系统,该系统是一种采用模糊技术来处理不确定性问题的模糊专家系统。系统的知识库、推理机都是在模糊理论的基础上构造的,其特点就是能够在初始信息不完全或不准确的情况下,较好地模拟人类专家解决问题的思路和方法,利用不完整的知识体系,给出尽可能准确的答案。     

DAD: a real-time expert system for monitoring of data packetnetworks

A project is described that has two goals: to explore the use of expert systems techniques for developing advanced operation support systems and to build a useful tool to assist the operators of the Canadian National Datapac network to cope with the rapid growth and evolution. Progress in developing and evaluating an advanced prototype system, DAD (Datapac Advisor), is reported. The prototype's environment and each of its functional components are described. The knowledge based design techniques used are highlighted, and the testing methodology and the results of a technical trial are described. Key findings are summarized, and their significance for the development of future network operation support systems is discussed     

ARIADNE: A constraint-based approach to computer-aided synthesis and modeling of Analog integrated circuits

The ARIADNE approach to computer-aided synthesis and modeling of analog circuits is presented. It is a mathematical approach based on the use of equations. Equations are regarded as constraints on a circuit's design space and analog circuit design is modeled as a constraint satisfaction problem. To generate and efficiently satisfy constraints, advanced computational techniques such as constraint propagation, interval propagation, symbolic simulation, and qualitative simulation are applied. These techniques cover design problems such as topology construction, modeling, nominal analysis, tolerance analysis, sizing and optimization of analog circuits. The advantage of this approach is the clear separation of design knowledge from design procedures. Design knowledge is modeled in declarative equation-based models (DEBMs). Design procedures are implemented into general applicable CAD tools. The ARIADNE approach closely matches the reasoning style applied by experienced designers. The integration of synthesis and modeling into one frame and the clear separation of design knowledge from design procedures eases the process of extending the synthesis system with new circuit topologies, turning it into an open design system. This system can be used by both inexperienced and experienced designers in either interactive or automated mode.     

谓词Petri网在防空C3I专家决策系统中的应用

军事专家系统是防空C^3I辅助决策系统中的重要组成部份,它利用人类专家的知识和解决问题的方法来解决该领域的问题,其实质是一个复杂的逻辑推理过程。如何描述其推理过程是设计专家系统首先必须解决的一个问题。因此,本文提出采用Petri网工具来描述防空C^3I军事专家决策系统的推理过程,大大地提高了决策的准确性,这也为描述专家系统提供了一种图示表示工具,可大大地提高系统的研发过程。     

Role conflict in design supervision

It is noted that managers planning to implement a CAD (computer-aided design) system concentrate most of their effort into technical analysis. Although some investigation is made into user participation and training, little attention is apparently paid to examining wider organization impacts. In particular, the role of the first-line supervisor in design can be fundamentally eroded when relationships change because of new technology. The authors report on the findings of some preliminary case studies of organizations with CAD systems, looking particularly at the supervisor role and its relationship with the CAD manager role. A revised organizational structure is proposed, in which the role of the lead designer takes over much of the traditional supervisor role, thereby overcoming many of the problems seen in existing organizations     

A hierarchical expert system for updating forestry maps with Landsat data

This paper reports upon the design of an expert system at the Canada Centre for Remote Sensing for updating maps of forested areas using Landsat imagery. The system is decomposed into a number of specialist experts organized in a hierarchical fashion around a series of blackboards which are used for communications between the different levels. At the lowest level in the hierarchy, is an expert which acts as the interface to the low-level, procedural-based, image processing algorithms. A short review of expert systems, with special emphasis on the analysis of remotely sensed imagery, is first given. Various approaches to treating uncertainty in expert systems are then discussed, in particular, the approach based upon the theory of evidence. The forestry map updating problem is described and the classical solution presented. Our hierarchically organized expert system is then presented in the context of this problem. Finally, an expert interface to the image processing algorithms is described.     

Interactive classification: A technique for acquiring and maintaining knowledge bases

The practical application of knowledge-based systems, such as in expert systems, often requires the maintenance of large amounts of declarative knowledge. As a knowledge base (KB) grows in size and complexity, it becomes more difficult to maintain and extend. Even someone who is familiar with the knowledge domain, how it is represented in the KB, and the actual contents of the current KB may have severe difficulties in updating it. Even if the difficulties can be tolerated, there is a very real danger that inconsistencies and errors may be introduced into the KB through the modification. This paper describes an approach to this problem based on a tool called an interactive classifier. An interactive classifier uses the contents of the existing KB and knowledge about its representation to help the maintainer describe new KB objects. The interactive classifier will identify the appropriate taxonomic location for the newly described object and add it to the KB. The new object is allowed to be a generalization of existing KB objects, enabling the system to learn more about existing objects.     

基于故障树分析的雷达故障诊断专家系统设计

快速进行故障诊断是保证雷达装备综合保障能力的前提,建立一套故障诊断专家系统来不断总结专家经验,从而使维修工作更加科学、有效。以某舰载搜索雷达系统为例,给出了雷达系统故障树的构建方法、故障诊断专家系统知识库的建立及推理机的设计,并简要介绍其实现方法。     

基于多值规则的知识表示及其应用

本文把多值逻辑引入专家系统中的知识表示,着重就模糊规则向多值规则的转换,二值规则和多值规则的混合表示,二值逻辑向多值逻辑的转换, 基于不同算子多值规则间的相互转换,以及采用管道结构从根本上解决专家系统中规则匹配速度慢等问题进行了研究,并首次将多值规则表示的知识用于电液位置伺服系统自适应律中的参数优化,进一步提高了控制器的性能.