Development of a feature-based and object-oriented concurrent engineering system

Product information modeling is critical to the integration of mechanical CAD/CAM systems and to the implementation of a concurrent engineering system. This paper presents a recent development of a feature-based and object-oriented concurrent engineering system with its focus on a product information modeling technique implemented in the system. The technique was developed to capture product definition data including form features and their spatial relationships and to store them as an object-oriented information model during the design process. The paper also describes the implementation of the information modeling technique and its application to manufacturing process planning in an object-oriented environment.     

A viable system structure for large‐scale software systems

A homogeneous system structure is proposed that enhances modularity and flexibility, and facilitates (further) development of large‐scale software systems in a major‐industry environment. In our opinion, it is an effective means of countering the inherent increase in software entropy when (further) developing existing large‐scale software systems, thereby substantially cutting down production costs. It can be applied generally both to new and existing systems, whether application programs or operating systems, promotes the parallel use of different programming paradigms and various implementation languages, and offers the option of either redesigning parts or introducing additional parts in stages based on a more modern technology. The proposed system structure is compared and contrasted with other architectures such as CORBA, and it is shown that it may be regarded as an embellishment of the CORBA architecture for the internal structuring or restructuring of possibly distributed software systems. So far it has been used in four releases of the BS2000/OSD operating system with very positive results. Dependencies between various entities – which we call ‘subsystems’ – in the course of the (further) development process, as well as during dynamic execution are minimized and well‐regulated. The subsystems may be loaded on demand during the session by a system authority. Every interface in the system is classified according to its permitted scope of use. For interfaces between subsystems, a uniform and standardized technique is introduced which uses the same format for all implementation languages at both the source‐ and binary‐code level. This technique exceeds the regulations in other architectures but actually achieves considerable rationalization. Copyright © 1999 John Wiley & Sons, Ltd.     

A System to Define and Allocate Health Care Resources on a Territory to Improve the Life Quality of the Populations in Developing Countries

In this paper the health resource allocation problem is discussed. An object-oriented system is proposed and its implemented prototype is illustrated. It consists of two parts: a Geographical Information System, which is able to acquire and store both geographical and social-epidemiological information (including the resource distribution on that territory), and a Decision Support System, able to decide, using optimization algorithms, the new resource allocation in order to obtain a quasi-optimal solution for the cost/benefit ratio minimization problem, after having fixed the goal (e.g., the decrease of the incidence of a given disease) and constraints (e.g., a fixed budget, a given set of available resources, etc.). The object-oriented database which is part of the system can simulate and store different scenarios, depending on the different goals and constraints defined in input, by means of a user friendly interface.     

面向对象软件覆盖度量的研究和软件测试工具的实现

面向对象软件测试技术的研究是面向对象方法不可缺少的一环，但是面对面向对象技术所引入的新特点，传统的测试技术已经无法有效地进行测试。因此，结合传统的测试技术，提出了一种新的面向对象软件覆盖度量-基于段的面向对象覆盖度量（object-oriented segment coverage），解决了传统的覆盖度量没有考虑到继承和多态等语言特征对面向对象软件软件测试过程的影响的不足，可以比传统的结构化覆盖度量获得更精确的测试覆盖数据。同时，还分析了一个已实现的、具有高度可重用性和灵活性的面向多种OO语言的测试工具的系统结构。     

Using an Issue-Based Hypertext System to Capture the Software Life-Cycle Process

Hypertext and object-oriented database technology offer significant possibilities for designing new software engineering environments which better represent the complex relationships between the many artifacts created during the life of a software system. These artifacts are composed of structured (machine understandable) and unstructured information. Hypertext systems can record both the structured and unstructured information of the software project and the linking relationships between both types of information. Issue-based information systems (also called argumentation systems) are special-purpose hypertext systems for capturing the issues and reasoning for decision making. The Issue-Based Experiment (IBE) system is an issue-based information system implemented on an object-oriented database platform. IBE was developed to research methods of capturing the life cycle of a software project in an issue-based information network. IBE is demonstrated to be useful in both the requirements development and system maintenance phases of the software life cycle. Several issues are discussed concerning the usability of issue-based information systems: maintaining a constant level of detail, scoping an Issue for placement in the issue network, and enforcing usage. IBE looks promising when integrated as part of a software development environment based on hypertext and object-oriented database technology.     

面向对象的动态图编辑器的设计与实现

提出了一种面向对象的动态图编辑器,该动态图编辑器区别一般图编辑器的方面在于：可以根据用户的需要在任何时候动态地执行用户程序定义的方法;产生可序列化的图;编辑部分和显示部分既能合并使用也能分开使用;允许用户定义任意形状的结点和弧;具有处理无向图和有向图的双重功能。用户可以分别利用交互式编辑环境和图布局机制输入小型图和中、大型图。动态图编辑器体系结构建立在软件工程设计模式和面向对象设计思想的基础上,用ＪＡ－ＶＡ２实现。     

Structuring fault-tolerant object systems for modularity in adistributed environment

The object-oriented approach to system structuring has found widespread acceptance among designers and developers of robust computing systems. The authors propose a system structure for distributed programming systems that support persistent objects and describe how properties such as persistence and recoverability can be implemented. The proposed structure is modular, permitting easy exploitation of any distributed computing facilities provided by the underlying system. An existing system constructed according to the principles espoused here is examined to illustrate the practical utility of the proposed approach to system structuring     

An application of structural modeling and automated reasoning to real-time systems design

This paper presents an application of structural modeling and automated reasoning as a software development environment for real-time systems. This application satisfies two major requirements for such an environment: (1) to synthesize an absolutely correct program and, (2) to increase software productivity. The real-time systems, which consist of concurrent programs, are described by a Prolog based concurrent object-oriented language, called MENDEL/87. As a typical concurrent program consists of two parts: functional and synchronization parts; the functional part in the reusable component to be registered in a library will be generated by a structural modeling through the use of structuring functions with respect to data flows. The synchronization part will be synthesized from temporal logic specifications by the use of an automated reasoning mechanism. This paper also describes the MENDELS ZONE implemented on a Prolog machine, which is the working base for the presented application method.     

Graph-Based Parallel Query Processing and Optimization Strategies for Object-Oriented Databases

Much work has been accomplished in the past on the subject of parallel query processing and optimization in parallel relational database systems; however, little work on the same subject has been done in parallel object-oriented database systems. Since the object-oriented view of a database and its processing are quite different from those of a relational system, it can be expected that techniques of parallel query processing and optimization for the latter can be different from the former. In this paper, we present a general framework for parallel object-oriented database systems and several implemented query processing and optimization strategies together with some performance evaluation results. In this work, multiwavefront algorithms are used in query processing to allow a higher degree of parallelism than the traditional tree-based query processing. Four optimization strategies, which are designed specifically for the multiwavefront algorithms and for the optimization of single as well as multiple queries, are introduced. The query processing algorithms and optimization strategies have been implemented on a parallel computer, nCUBE2; and the results of a performance evaluation are presented in this paper. The main emphases and the intended contributions of this paper are (1) data partitioning, query processing and optimization strategies suitable for parallel OODBMSs, (2) the implementation of the multiwavefront algorithms and optimization strategies, and (3) the performance evaluation results.     

A graph mining approach for detecting identical design structures in object-oriented design models

The object-oriented approach has been the most popular software design methodology for the past twenty-five years. Several design patterns and principles are defined to improve the design quality of object-oriented software systems. In addition, designers can use unique design motifs that are designed for the specific application domains. Another commonly used technique is cloning and modifying some parts of the software while creating new modules. Therefore, object-oriented programs can include many identical design structures. This work proposes a sub-graph mining-based approach for detecting identical design structures in object-oriented systems. By identifying and analyzing these structures, we can obtain useful information about the design, such as commonly-used design patterns, most frequent design defects, domain-specific patterns, and reused design clones, which could help developers to improve their knowledge about the software architecture. Furthermore, problematic parts of frequent identical design structures are appropriate refactoring opportunities because they affect multiple areas of the architecture. Experiments with several open-source and industrial projects show that we can successfully find many identical design structures within a project (intra-project) and between different projects (inter-project). We observe that usually most of the detected identical structures are an implementation of common design patterns; however, we also detect various anti-patterns, domain-specific patterns, reused design parts and design-level clones.     

基于.NET平台的三层架构软件框架的设计与实现

面向对象和构件的软件开发平台,几乎是现在信息系统开发的必备之物,通过在平台之上融入三层架构及复用技术来构建一个功能丰富,结构灵活的软件框架也成为现在应用系统开发的主流思想。在介绍分析软件复用技术和三层架构思想的基础之上,研究并提出了基于.NET环境的三层架构信息系统软件框架设计的基本思路和方法,同时运用C#语言实现了该软件框架的代码自动生成器。信息系统开发时通过运用该软件框架代码生成器可以很方便的生成一个MIS雏形,从而能有效的提高信息系统软件的开发效率和软件标准化及构件化水平。     

Expert systems in engineering design: an application for injection molding of plastic parts

The rich development environments of expert system shells provide tools for developing knowledge-based expert systems for complex tasks such as engineering design. The diverse knowledge in engineering design combines heuristics with deterministic knowledge, from multiple sources, and involves complicated, interrelated components. The hybrid capabilities in emerging expert system tools effectively address this diverse knowledge, and facilitate the rapid development of design aids by the engineering designer. A prototype expert system for injection-molded plastic parts demonstrates the utility of expert systems for design applications. The prototype is implemented in an object-oriented, rule-based environment, and incorporates solid modeling software and external material databases.     

An IDSS development environment based on consistent language

This paper describes the architecture of an object-oriented and open intelligent decision support system (IDSS) development environment (IDSS DE), in which parts of the IDSS system can be integrated consistently. A consistent objectoriented representation language, Knonit, is proposed. Its concept, grammar, execution and other major characteristics are discussed as well.     

面向对象的顺控输送系统编程方法

将面向对象方法引入复杂逻辑顺序控制系统，提出将逻辑关系分成两部分，设备及相关的自有逻辑经抽象与封装成为设备对象，设备之间的逻辑则被封装到虚拟的流程对象中，通过对象之间的消息交互实现顺序控制功能。采用面向对象方法，顺序控制系统编程可以从实现复杂的逻辑运算转变成创建两类对象和建立对象之间的消息传递机制以一个输送系统为例阐明面向对象方法可以显著提高编程效率，增强系统的可扩充性，面向对象方法为顺控系统的建模、优化等进一步研究提供了一个新思路。     

Knowledge acquisition techniques for feature recognition in CAD models

Automatic Feature Recognition (AFR) techniques are an important tool for achieving a true integration of design and manufacturing stages during the product development. In particular, AFR systems offer capabilities for recognising high-level geometrical entities, features, in Computer-Aided Design (CAD) models. However, the recognition performances of most of the existing AFR systems are limited to the requirements of specific applications. This paper presents automatic knowledge acquisition techniques to support the development of AFR systems that could be deployed in different application domains. In particular, a method to generate automatically feature recognition rules is proposed. These rules are formed by applying an inductive learning algorithm on training data consisting of feature examples. In addition, a technique for defining automatically feature hints from such rule sets is described. The knowledge acquisition techniques presented in this study are implemented within a prototype feature recognition system and its capabilities are verified on two benchmarking parts.     

特定应用的嵌入式操作系统构造方法研究

随着通用型嵌入式实时操作系统的发展，一个以面向Internet网络的、特定应用的嵌入式操作系统成为实时嵌入式系统极为重要的发展方向。本文详细阐述了特定应用嵌入式操作系统ASOS(Application Specific embedded Operating Systems)的概念和特点，提出了ASOS的三种构造方法：面向对象技术，组件技术，模式生成。     

An automated coding and classification system with supporting database for effective design of manufacturing systems

The philosophy of group technology (GT) is an important concept in the design of flexible manufacturing systems and manufacturing cells. Group technology is a manufacturing philosophy that identifies similar parts and groups them into families. Beside assigning unique codes to these parts, group technology developers intend to take advantage of part similarities during design and manufacturing processes. GT is not the answer to all manufacturing problems, but it is a good management technique with which to standardize efforts and eliminate duplication. Group technology classifies parts by assigning them to different families based on their similarities in: (1) design attributes (physical shape and size), and/or (2) manufacturing attributes (processing sequence). The manufacturing industry today is process focused; departments and sub units are no longer independent but are interdependent. If the product development process is to be optimized, engineering and manufacturing cannot remain independent any more: they must be coordinated. Each sub-system is a critical component within an integrated manufacturing framework. The coding and classification system is the basis of CAPP and the functioning and reliability of CAPP depends on the robustness of the coding system. The proposed coding system is considered superior to the previously proposed coding systems, in that it has the capability to migrate into multiple manufacturing environments. This article presents the design of a coding and classification system and the supporting database for manufacturing processes based on both design and manufacturing attributes of parts. An interface with the spreadsheet will calculate the machine operation costs for various processes. This menu-driven interactive package is implemented using dBASE-IV. Part Family formation is achieved using a KAMCELL package developed in TURBO Pascal.     

Knowledge-based approach and system for assembly-oriented design,Part II: the system implementation

Assembly is one of the most important stages for product development. Assembly-oriented design (AOD) is a new approach to designing assemblies, which uses a number of design and analysis tools to help the designer plan out and analyze candidate assembly schemes prior to having detailed knowledge of the geometry of the parts. Using this approach, many assembly schemes can be inexpensively evaluated for their ability to deliver the important characteristics of the final product. This research proposes a knowledge-based approach and develops an expert design system to support top-down design for assembled products. The presentation of research report is divided into two parts: the knowledge-based approach (Part I) and the knowledge-based expert design system (Part II). This paper is the second part of the report (Part II). It will focus on the development of knowledge-based expert design system for assembly oriented design. The knowledge-based assembly oriented design system, i.e., the assembly oriented design expert system (AODES) is constructed to integrate assembly modeling and design, assembly planning, assemblability analysis and evaluation within a concurrent engineering environment. This intelligent system is implemented by integrating object-oriented representation, constraint-based modeling, rule-based reasoning, truth maintenance, and interfacing to database management system and CAD module, in which fuzzy logic based knowledge representation and inference technique are also applied to deal with uncertain data and knowledge in the design process. The developed system differs from the existing systems adopting part-first bottom-up modeling technique, in which a comprehensive intelligent framework is used for assembly modeling and design in a top-down manner from the conceptual level to the detailed level. It is able to help obtain better design ideas, provide users with suggestions so as to create and improve a design, and therefore give users the possibility to assess and reduce the total production cost at an early stage during the design process. Through the use of the system, the concurrent engineering knowledge can be effectively incorporated into the assembly design process in an integrated manner. A case assembly design shows that the intelligent modeling and design system is feasible.     

Symbolic manipulation techniques for model simplification in object-oriented modelling of large scale continuous systems

In the present work, techniques for the symbolic manipulation of general nonlinear differential algebraic equation (DAE) systems are presented, and used for model simplification purposes, to support efficient simulation of large scale continuous systems in an object-oriented modelling environment. The specific problems addressed are efficient elimination of trivial equations by means of substitution, system block lower triangular (BLT) partitioning, and tearing, i.e. hiding of algebraic variables. Moreover, the weakening heuristic criterion for decoupling of large systems, via dynamic approximation, is studied. All these techniques have been successfully implemented and tested in MOSES (modular object-oriented software environment for simulation), in order to define a complete model simplification process. The results achieved by applying the discussed algorithms and criteria on serial multibody systems are illustrated. A brief overview on further known symbolic manipulation techniques is also given, comparing them with the proposed ones, throughout the paper.     

A Generic Reification Technique for Object-Oriented Reflective Languages

Computational reflection is gaining interest in practical applications as witnessed by the use of reflection in the Java programming environment and recent work on reflective middleware. Reflective systems offer many different reflection programming interfaces, the so-called Meta-Object Protocols (MOPs). Their design is subject to a number of constraints relating to, among others, expressive power, efficiency and security properties. Since these constraints are different from one application to another, it would be desirable to easily provide specially-tailored MOPs.In this paper, we present a generic reification technique based on program transformation. It enables the selective reification of arbitrary parts of object-oriented meta-circular interpreters. The reification process is of fine granularity: individual objects of the run-time system can be reified independently. Furthermore, the program transformation can be applied to different interpreter definitions. Each resulting reflective implementation provides a different MOP directly derived from the original interpreter definition.