On interfaces

The nature of interfaces is discussed. It is recommended that modern software approaches to interfaces (such as abstract data types) be extended to interfaces of all kinds. These interfaces can and should be developed at the level of abstraction appropriate to the interacting elements, rather than at the level of their lowest common denominator, which is frequently the case. It is proposed that for an interface to exist at any level of abstraction, there must be an operational framework that implements that level of abstraction and within which the interfacing elements interact. Four tasks required for the development of interfaces are described. The traditional classification of interfaces as hardware/software, software/software, and hardware/hardware is found wanting and a new partitioning is suggested—structural or interpretive interfaces, symbolic interfaces, and physical interfaces. Standards and scientific and engineering theories are shown to define levels of abstraction for general interfaces in much the same way that programming languages do for software interfaces. Implications for software engineering and concurrent engineering are explored.     

面向用户构造企业信息系统

本文在对当前企业中信息系统面临的问题进行分析的基础上，提出了面向用户构造企业信息系统的方法，即全面考察实际系统中对象的整个生命周期过程和对象间的内在联系，使设计出的应用系统可由最终用户自行调整，以适应实际系统的信息需求的变化。论文提出了面向用户的企业信息系统的软件结构，最后简要介绍了采用面向用户方法进行开发的实例。     

An object-oriented approach to Computer Integrated Systems

In recent years computers have been incorporated into large scale systems such as nuclear plant, flight control, and manufacturing systems. Such Computer Integrated Systems (CIS) normally consist of heterogeneous subsystems. The integration of heterogeneous subsystems requires that the subsystems be portable, inter-operable, and integrable at both software and hardware levels so that the integrated system should function properly. Objects and nets are proposed as the atomic elements of CIS's. An object is defined as a computational model of an arbitrary entity. Then three representation schemes of an object are introduced: algebraic, modular, and graphical. Two operations on objects,Composition andUnion, are introduced as means of combining two objects into a larger one. As an application of this approach, a Computer Integrated Manufacturing (CIM) system is represented as a network of objects.     

CIM建模技术在电力二次系统设备中的应用

针对目前电力系统存在的模型不统一问题,对CIM模型做了进一步的理解,并尝试提出一种对电力二次系统设备的CIM建模方法,构建电力二次设备的CIM模型,以变压器保护的CIM建模来验证该方法的正确性和可行性,为进一步建立完整的电力二次系统CIM模型奠定基础。     

基于CIM的变电站与配电馈线一次接线图自动绘制算法

基于IEC 61970/IEC 61968的公共信息模型规范,建立了关于配电网一次系统的数据服务平台;介绍了变电站内电压等级与间隔容器的分类及其类型识别方法。在图形布局时,对变电站采用分而治之的思想,递归地布局子容器;针对馈线辐射状或弱环状的特点,采用树形布局法;图形布局过程结合深度优先搜索法和堆栈技术。提出的自动绘图方法可使配电网中不同应用系统之间实现高度的图形与数据资源共享。     

广东省地区电网外网等值自动生成系统设计

为了使地区电网能量管理系统(EMS)计算准确,需要省级电网调度中心自动计算并发送外网等值信息。为此,设计了便于地区电网应用的外网等值参数自动生成系统框架。该系统实时反映网络拓扑的变化,并与动态等值计算参数相配合,以公用对象请求代理程序结构(CORBA)规范完成数据通信平台,按公用信息模型(CIM)标准完成从SCADA／EMS的模型转化,随时为地区电网实时网络分析提供开放、灵活、方便的外网等值模型,大大减少了地区电网EMS的维护工作量,提高了计算精度。     

基于CIM的安全预警系统建模

随着信息安全问题受到越来越多的关注,安全管理工具也得到广泛应用。公共信息模型（CIM）目前仍是一个较新的发展领域,近年来越来越多地被应用到各项管理平台。针对信息安全管理的现状和需求,论文提出了一种基于CIM的安全预警系统的构思和建模：利用CIM对系统状态、攻击策略等对象进行建模,从关联关系和状态变化事件中发现安全隐患,从而实现对潜在的安全威胁的预警。     

An exploration of simultaneous engineering for manufacturing enterprises

With the increasing application of high technology in manufacturing enterprises, the traditional serial or sequential production approach has begun to be replaced by a parallel or simultaneous production approach. The functional balance of organisations of current manufacturing enterprises is decline. The organisation within manufacturing enterprises needs to be restructured and the functions need to be adjusted. Many production functions within an enterprise can be integrated by following the production information. This is the premise of this exploration of simultaneous engineering in manufacturing enterprises. A functional model of an enterprise is described in this paper. Some possibilities of functional integration within an enterprise are discussed. Finally, some related research activities are outlined to stimulate an open discussion on the point of view.     

计算机数控集成技术的发展

综述了国内外计算机数控接口的发展现状，简述了计算机数控集成系统的结构，阐述了基于ＤＮＣ的集成系统的发展背景，提出了计算机数控集成技术的几点发展趋势。     

A Generative Computer-Aided Process Planning System for Prismatic Components

This paper deals with design and development of a generative computer-aided process planning (CAPP) system for prismatic components and named PSG-CAPP. The proposed CAPP system has been divided into three modules. The first module is concerned with feature extraction. The second and third modules deal with planning the set-up, machine selection, cutting tool selection, cutting parameter selection, and generation of process plan sheet. The whole CAPP system is developed using Visual Basic 6.0 as front end and Oracle 7.3 as back end. The SolidWorks98 plus has been used for modelling, and feature extraction has been implemented using a program written in Visual Basic 6.0. The speciality of the developed CAPP system is that it is linked with the CAD module and it extracts the majority of features automatically prior to process planning. The developed CAPP system has been tested with aerospace components. The main feature of the proposed CAPP system is its ability to handle a variety of prismatic components and generate process plans for them. A case study has been included to highlight the potential of the CAPP system. ID="A1"Correspondance and offprint requests to: Professor P. V. Mohanram, Department of Mechanical Engineering, PSG College of Technology, Peelamedu, Coimbatore 641004, India. E-mail: msadaiah@yahoo.com