A knowledge system for integrated product design

This paper discusses the architecture and implementation issues for a knowledge system to assist in product design. The goals of the concurrent Design Advisor (CODA) are to enhance the quality of designs by 25 percent and the efficiency by a factor of 10. The improvement springs from the integration of diverse knowledge bases, ranging from customer needs to product evaluation, and from process configuration to production control. One source of efficiency is the automation of many routine tasks, thereby increasing user productivity. Another source is the increase in the quality of initial designs, which obviates the need for numerous iterations in the design process due to poor manufacturability. CODA is based on the general architecture of the Creativity Support System, an expert system for assisting users in specific domains requiring creative solutions. The bilevel structure of the system consists of a domain-independent module containing general tools and techniques for creative problem-solving, and a domain-dependent module incorporating knowledge specific to particular fields of application. The utility of this approach is illustrated in the realm of concurrent product design by demonstrating a CODA within the general architecture of the system.     

A non-invasive object-oriented tool for software testing

A non-invasive approach for capture and playback (C&P) can be a very useful tool for testing applications endowed of a graphic user interface in local and/or distributed environments, and in general for testing applications without modifying their run-time environment. In the software lifecycle, the phases ofC&P are performed after the application design. Since these are close to the delivery deadline, the time needed for application testing is considered as a high, and frequently unacceptable, cost. In this paper, a new approach for non-invasiveC&P testing techniques is proposed. This is strongly based on the object-oriented paradigm at both hardware and software levels. In particular, a new board for image grabbing and pattern matching, and a new object-oriented language for specifying the tests have been defined. The main goals of this new approach are (i) the reduction of testing time by supporting the reuse of tests (coded by using a specific language) at each level of abstraction, and (ii) the anticipation of the capture-phase of testing with the system design.     

Object-oriented software modeling of a Flexible Manufacturing System

Flexible Manufacturing Systems play an important role in improving our manufacturing productivity. Simulation is emerging as a popular tool in modeling FMS for analyzing its performance in the area of production planning/scheduling. In this paper, we illustrate how to model a Flexible Manufacturing System in the object-oriented paradigm using an example. We present a systemtic approach to the design of object-oriented programming systems based on a combination of data modeling and event analysis techniques.An entity relationship approach is used as the basis for an initial decomposition of the system into objects. The design is refined by an analysis of the events the objects participate in. The design is implemented in Objective-C. Finally, we describe ways in which this model of an FMS can be extended to explore popular research questions in production planning and scheduling.     

An expert system for the selection of software design patterns

Abstract: This paper describes the development of a prototype expert system for the selection of design patterns that are used in object-oriented software. Design patterns provide one method of software reuse, which supports the goal of improved software development productivity. The prototype system represents an initial step towards providing an automated solution regarding the design pattern application problem, i.e. leading a designer to a suitable design pattern which is applicable to the problem at hand. The feasibility of using expert system technology to aid in the selection problem is demonstrated.     

小卫星软件共用平台设计

以小卫星共用平台相配套,以面向对象的程序设计方法（OOP）为基础,提出软件共用平台的设计。利用OOP的封装性、继承性和多态性,设计小卫星软件的基本类库,介绍各个基本类的具体设计思想。最后给出由基本类库生成星载机软件系统的实例。实践表明,软件共用平台对小卫星研制是行之有效的技术。     

A program design language based software maintenance tool

Program design languages are an increasingly important method of expressing the detailed design of a software system. Such languages can be modelled using a data structure known as a semantic net. This paper describes a maintenance tool for program design languages based on such a data structure. The tool allows the user to interrogate a semantic net using an interactive procedural language in order to derive information necessary for software maintenance. The technique upon which this tool is based is applicable to the maintenance of activities throughout the software lifecycle.     

A tool for design pattern detection and software architecture reconstruction

It is well known that software maintenance and evolution are expensive activities, both in terms of invested time and money. Reverse engineering activities support the obtainment of abstractions and views from a target system that should help the engineers to maintain, evolve and eventually re-engineer it. Two important tasks pursued by reverse engineering are design pattern detection and software architecture reconstruction, whose main objectives are the identification of the design patterns that have been used in the implementation of a system as well as the generation of views placed at different levels of abstractions, which let the practitioners focus on the overall architecture of the system without worrying about the programming details it has been implemented with.In this context we propose an Eclipse plug-in called MARPLE (Metrics and Architecture Reconstruction Plug-in for Eclipse), which supports both the detection of design patterns and software architecture reconstruction activities through the use of basic elements and metrics that are mechanically extracted from the source code. The development of this platform is mainly based on the exploitation of the Eclipse framework and plug-ins as well as of different Java libraries for data access and graph management and visualization. In this paper we focus our attention on the design pattern detection process.     

A software tool for top-down programming

Top-down design and programming methods have become well established in both commercial and academic environments. However, a programmer using such methods faces a number of organizational difficulties. This paper describes a software tool, written in Pascal, which eliminates these difficulties. It allows a programmer to interactively develop programs in a top-down fashion.     

A new programming paradigm for engineering design software

Currently available programming and database systems are insufficient for engineering applications. The authors contend that a logical progression from a formal conceptual model of the engineering domain to a computational model will lead to new programming paradigms capable of directly supporting engineering applications in a rigorous, concise manner. A formal domain model devised by the authors, theHybrid Model (HM) of design information, is briefly introduced. It is an extension of axiomatic set theory and is discussed in detail elsewhere. HM forms the basis ofDesigner, a prototype-based object-oriented programming language supporting a signature-based canonical message-passing mechanism and multiple inheritance. Designer is implemented using the Scheme programming language. Because Designer satisfies a formal conceptual model, and because it is based on a formally specified language, its robustness and logical validity are superior to those of other languages not founded on formal principles. Designer combines concepts of functional and object-oriented programming to provide the formal rigor and flexibility to capture the complex and strongly interrelated information that designers use. Examples demonstrate how Designer represents design information. The results of the authors' research indicate that Designer can capture design information (including aspects of functional requirements and design intent) effectively and efficiently.     

Integrated product and process design: a multi-objective modeling framework

In this paper we present an analytical multi-objective framework for the concurrent design of product and processes. The objective is to simultaneously consider the tolerance specification on the product or the component dimensions along with the selection of the manufacturing processes. For this purpose we consider three objectives: to minimize unit cost, to minimize quality loss and to minimize manufacturing lead time. We characterize the properties of the non-dominated solutions. These solutions provide flexibility needed in an agile manufacturing environment. The min–max approach is used to obtain trade-off solutions.     

OpenTracker: A flexible software design for three-dimensional interaction

Tracking is an indispensable part of any virtual reality and augmented reality application. While the need for quality of tracking, in particular for high performance and fidelity, has led to a large body of past and current research, little attention is typically paid to software engineering aspects of tracking software. To address this issue we describe a software design and implementation that applies the pipes-and-filter architectural pattern to provide a customizable and flexible way of dealing with tracking data and configurations. The contribution of this work cumulates in the development of a generic data flow network library called OpenTracker to deal specifically with tracking data. The flexibility of the data flow network approach is demonstrated in a set of development scenarios and prototype applications in the area of mobile augmented reality.     

NUAPC: A Parallelizing Compiler for C++

is paper presents a model for automatically parallelizing compiler based on C which consists of compile-time and run-time parallelizing facilities.The paper also describes a method for finding both intra-object and inter-object parallelism.The parallelism detection is completely transparent to users.     

A part affordance-based approach for capturing detailed design knowledge

Design knowledge reuse is widely accepted as an effective strategy for designers to develop robust artifacts with less time and lower cost. However, there has been very little research on how to help designers capture detailed design knowledge for reuse. As a result, most detailed design knowledge still has to remain in designers’ memories as tacit knowledge, which can easily get lost due to oblivion or the mobility of designers. Therefore, this paper attempts to develop a part affordance-based approach for externalizing and capturing detailed design knowledge for effective reuse. It first introduces a part model for representing the detailed design-related information. Based on the relational theory for design, the concept, part affordance, is then employed to help designers externalize and capture various lifecycle factors that are implicit in a detailed design. Based on the affordance constraint axiom, a systematic approach is then proposed for deriving tacit design knowledge from captured part affordances through the analysis of extreme working situations. The proposed approach has been implemented as the Design Knowledge-Capturing System (DKCS). A fixture design case has been employed to illustrate the proposed approach.     

A CASE tool for software architecture design

This paper describes the Software Architect's Assistant, an automated visual tool for the design and construction of Regis distributed programs. Unlike conventional CASE tools and their supported methodologies, the Architect's Assistant supports a compositional approach to program development in which the software architecture plays a central role throughout the software life-cycle—from the early design stage through to system management and evolution.In its implementation, we have addressed some of the limitations of existing CASE tools, particularly in the degree of automated support offered to the human developer. Conscious effort has been made to maximise usability and efficiency, primarily by enhancing the level of automation and flexibility together with careful design of the user interface. Our objective is to provide a tool which automates all mundane clerical tasks, enforces program correctness and consistency and, at the same time, accommodates the individual working styles of its users.Although currently specific to the development of Regis programs, the Architect's Assistant embodies concepts and ideas which are applicable to CASE tools in general.     

A survey on search-based software design

This survey investigates search-based approaches to software design. The basics of the most popular meta-heuristic algorithms are presented as background to the search-based viewpoint. Software design is considered from a wide viewpoint, including topics that can also be categorized as software maintenance or re-engineering. Search-based approaches have been used in research from the high architecture design level to software clustering and finally software refactoring. Enhancing and predicting software quality with search-based methods is also taken into account as a part of the design process. The background for the underlying software engineering problems is discussed, after which search-based approaches are presented. Summarizing remarks and tables collecting the fundamental issues of approaches for each type of problem are given. The choices regarding critical decisions, such as representation and fitness function, when used in meta-heuristic search algorithms, are emphasized and discussed in detail. Ideas for future research directions are also given.     

Eliminating synchronization faults in air traffic control software via design for verification with concurrency controllers

The increasing level of automation in critical infrastructures requires development of effective ways for finding faults in safety critical software components. Synchronization in concurrent components is especially prone to errors and, due to difficulty of exploring all thread interleavings, it is difficult to find synchronization faults. In this paper we present an experimental study demonstrating the effectiveness of model checking techniques in finding synchronization faults in safety critical software when they are combined with a design for verification approach. We based our experiments on an automated air traffic control software component called the Tactical Separation Assisted Flight Environment (TSAFE). We first reengineered TSAFE using the concurrency controller design pattern. The concurrency controller design pattern enables a modular verification strategy by decoupling the behaviors of the concurrency controllers from the behaviors of the threads that use them using interfaces specified as finite state machines. The behavior of a concurrency controller is verified with respect to arbitrary numbers of threads using the infinite state model checking techniques implemented in the Action Language Verifier (ALV). The threads which use the controller classes are checked for interface violations using the finite state model checking techniques implemented in the Java Path Finder (JPF). We present techniques for thread isolation which enables us to analyze each thread in the program separately during interface verification. We conducted two sets of experiments using these verification techniques. First, we created 40 faulty versions of TSAFE using manual fault seeding. During this exercise we also developed a classification of faults that can be found using the presented design for verification approach. Next, we generated another 100 faulty versions of TSAFE using randomly seeded faults that were created automatically based on this fault classification. We used both infinite and finite state verification techniques for finding the seeded faults. The results of our experiments demonstrate the effectiveness of the presented design for verification approach in eliminating synchronization faults.     

间歇精馏设计软件的开发

利用Visual Basic 6.0语言开发间歇精馏常规设计及优化设计软件。软件可用于不同物系(二元理想及非理想溶液),采用不同操作方式(恒馏出液组成操作和恒回流比操作)间歇精馏的常规设计和优化设计(包括单变量优化和多变量优化)计算。软件采用面向对象的编程技术,对精馏组分的物性参数、汽液相平衡数据实行数据库操作,界面友好,使用方便。     

带有超大型挠性网状天线航天器姿控系统的参数化多目标设计

本文研究了带有超大型挠性附件的卫星的姿态控制问题.关于挠性航天器振动抑制与姿态控制,绝大多数已有的控制方法都是针对某一单一指标提出的.然而工程上要同时兼顾精度、快速性、平稳性、挠性部件的振动抑制以及各种鲁棒性,因此挠性航天器的姿态控制系统设计实际上是一个典型的多目标设计问题.本文针对具有超大挠性网状天线卫星的俯仰通道姿态系统,提出了一种基于输出反馈的鲁棒极点配置的参数化多目标设计方法.首先给出了系统能控与能观的充分必要条件,然后给出了动态补偿器以及特征向量矩阵的参数化表达,并在此基础上进一步对自由参向量进行了多目标优化,使得控制系统具有:1)配置到期望区域的极点; 2)较低的特征值灵敏度;3)较强的高阶未建模动态抑制能力; 4)尽可能小的控制增益.最后,本文根据卫星工程参数进行了控制器设计与仿真验证,仿真结果表明本文提出的方法可以在动态响应、高阶未建模动态抑制能力、控制量峰值等方面优于传统的PID控制器.     

The software information base: A server for reuse

We present an experimental software repository system that provides organization, storage, management, and access facilities for reusable software components. The system, intended as part of an applications development environment, supports the representation of information about requirements, designs and implementations of software, and offers facilities for visual presentation of the soft-ware objects. This article details the features and architecture of the repository system, the technical challenges and the choices made for the system development along with a usage scenario that illustrates its functionality. The system has been developed and evaluated within the context of the ITHACA project, a technology integration/software engineering project sponsored by the European Communities through the ESPRIT program, aimed at developing an integrated reuse-centered application development and support environment based on object-oriented techniques.