A formal framework for on-line software version change

The usual way of installing a new version of a software system is to shut down the running program and then install the new version. This necessitates a sometimes unacceptable delay during which service is denied to the users of the software. An online software replacement system replaces parts of the software while it is in execution, thus eliminating the shutdown. While a number of implementations of online version change systems have been described in the literature, little investigation has been done on its theoretical aspects. We describe a formal framework for studying online software version change. We give a general definition of validity of an online change, show that it is in general undecidable and then develop sufficient conditions for ensuring validity for a procedural language     

Introduction of modern software technology. A case from Swedish industry

A project to develop a new system, Core Master 2, was undertaken in Sweden in 1990. This is a relatively large system, for nuclear power plant core engineering. Main project goals were to increase end-user productivity while reducing user-induced errors and software life-cycle costs. To meet them and improve software quality, object-oriented technology was adopted. The software process became much slower than expected. Learning aspects related to the new technology and changing specifications account for most of the delay. The first version is now ready and is being shipped to customers. Lessons learned from the process, education and training are discussed     

动态数据访问方式探讨

随着计算机网络技术的日益“平民化”和软件信息化的发展,以及由各种在线功能如在线翻译、在线杀毒等联想到的给用户带来的方便,基于Web下的软件开发（网络化软件）成为时下的研究热点。而此过程中必须要面对的一个难题是制作的软件如何在客户端访问,即实现服务器端软件与浏览器（IE）的“无缝焊接”,这就涉及到动态数据访问技术。本文将着眼于实际工程和系统开发的需要,详细地分析和对比了动态数据访问几种方式,特别是基于PHP的动态数据访问方式。     

Understanding the triaging and fixing processes of long lived bugs

ContextBug fixing is an integral part of software development and maintenance. A large number of bugs often indicate poor software quality, since buggy behavior not only causes failures that may be costly but also has a detrimental effect on the user’s overall experience with the software product. The impact of long lived bugs can be even more critical since experiencing the same bug version after version can be particularly frustrating for user. While there are many studies that investigate factors affecting bug fixing time for entire bug repositories, to the best of our knowledge, none of these studies investigates the extent and reasons of long lived bugs.ObjectiveIn this paper, we investigate the triaging and fixing processes of long lived bugs so that we can identify the reasons for delay and improve the overall bug fixing process.MethodologyWe mine the bug repositories of popular open source projects, and analyze long lived bugs from five different perspectives: their proportion, severity, assignment, reasons, as well as the nature of fixes.ResultsOur study on seven open-source projects shows that there are a considerable number of long lived bugs in each system and over 90% of them adversely affect the user’s experience. The reasons for these long lived bugs are diverse including long assignment time, not understanding their importance in advance, etc. However, many bug-fixes were delayed without any specific reasons. Furthermore, 40% of long lived bugs need only small fixes.ConclusionOur overall results suggest that a significant number of long lived bugs may be minimized through careful triaging and prioritization if developers could predict their severity, change effort, and change impact in advance. We believe our results will help both developers and researchers better to understand factors behind delays, improve the overall bug fixing process, and investigate analytical approaches for prioritizing bugs based on bug severity as well as expected bug fixing effort.     

An Installable Version Control File System for Unix

We present a file system named VCFS, a Version Control File System that provides transparent version control of files. VCFS is implemented as an installable file system in the Unix operating system. The facility is transparent to users in the sense that VCFS automatically stores changes between incremental versions of a file without user intervention. Access to the latest version of the file retains traditional Unix semantics, enabling all existing Unix applications to be run modified under VCFS if so desired. VCFS provides system call enhancements and supports application level utilities for version number retrieval, displaying changes between two versions of a file, upgrading to a new release number, and related version control functions. Performance measurements show that VCFS provides a significant increase in version control operations compared to application level change management systems such as SCCS, and that the space utilization is significantly better than of the existing version control systems. The primitives and facilities provided by VCFS can be exploited for use in a wide range of applications, ranging from immutable files, transaction processing and file replication support in a distributed file system, to the development of enhanced change management control systems for software project management. © 1997 John Wiley & Sons, Ltd.     

The development of a theoretical framework and design tool for process usability assessment

The purpose of usability engineering is to facilitate the deployment of new products by decreasing development costs and improving the quality of systems. This paper will discuss the development and delivery of a unique, theoretically based software tool that provides engineers and designers with easy access to the most recent advances in human-machine interface design. This research combines several theoretical views of the interaction process into a hybrid model. Based on this model, a software tool was produced that allows engineers to model the human interaction process within their design. The system then provides feedback on the interaction process through items such as: the amount of mental effort required by a user, the degree to which the system conforms to human capabilities, the expected time to complete the interaction, where potential human error may occur, as well as potential misunderstandings or points of confusion to the users. The designer may then use this information to improve the design of the system. Validation of this technique indicates that the hybrid model produces accurate predictions of usability attributes and that the technique transfers from the laboratory to the real world.     

The development of a theoretical framework and design tool for process usability assessment

The purpose of usability engineering is to facilitate the deployment of new products by decreasing development costs and improving the quality of systems. This paper will discuss the development and delivery of a unique, theoretically based software tool that provides engineers and designers with easy access to the most recent advances in human-machine interface design. This research combines several theoretical views of the interaction process into a hybrid model. Based on this model, a software tool was produced that allows engineers to model the human interaction process within their design. The system then provides feedback on the interaction process through items such as: the amount of mental effort required by a user, the degree to which the system conforms to human capabilities, the expected time to complete the interaction, where potential human error may occur, as well as potential misunderstandings or points of confusion to the users. The designer may then use this information to improve the design of the system. Validation of this technique indicates that the hybrid model produces accurate predictions of usability attributes and that the technique transfers from the laboratory to the real world.     

Structure and software tools of AIDA

AIDA consists of a set of software tools to allow for fast development and easy-to-maintain Medical Information Systems. AIDA supports all aspects of such a system both during development and operation. It contains tools to build and maintain forms for interactive data entry and on-line input validation, a database management system including a data dictionary and a set of run-time routines for database access, and routines for querying the database and output formatting. Unlike an application generator, the user of AIDA may select parts of the tools to fulfill his needs and program other subsystems not developed with AIDA. The AIDA software uses as host language the ANSI-standard programming language MUMPS, an interpreted language embedded in an integrated database and programming environment. This greatly facilitates the portability of AIDA applications. The database facilities supported by AIDA are based on a relational data model. This data model is built on top of the MUMPS database, the so-called global structure. This relational model overcomes the restrictions of the global structure regarding string length. The global structure is especially powerful for sorting purposes. Using MUMPS as a host language allows the user an easy interface between user-defined data validation checks or other user-defined code and the AIDA tools. AIDA has been designed primarily for prototyping and for the construction of Medical Information Systems in a research environment which requires a flexible approach. The prototyping facility of AIDA operates terminal independent and is even to a great extent multi-lingual. Most of these features are table-driven; this allows on-line changes in the use of terminal type and language, but also causes overhead. AIDA has a set of optimizing tools by which it is possible to build a faster, but (of course) less flexible code from these table definitions. By separating the AIDA software in a source and a run-time version, one is able to write implementation-specific code which can be selected and loaded by a special source loader, being part of the AIDA software. This feature is also accessible for maintaining software on different sites and on different installations.     

分布式网络设备的业务不中断软件升级系统设计①

以往用软件升级来增加新的特性和能力或软件维护是导致网络系统中断的主要原因之一。以冗余路由器为例,设计了一种能在分布式网络设备上实现业务不中断的软件在线升级系统,利用不中断转发（NSF）、状态转换（SSO）、热补丁、进程间通信（IPC）和主控硬件冗余等现有成熟技术在用户流量不中断转发的情况下真正实现了软件在线升级和版本替换,在升级过程中涉及到兼容性检查,回滚定时器设计等内容,有效地解决或减少了软件升级带来的业务中断现象,进一步提高了网络设备的高可用性。     

基于MC13213的无线多跳信报箱告知系统设计

为了实现对多层住宅信报箱报件到达的自动检测,提出了一种基于MC13213的无线多跳信报箱告知系统,并完成系统的软硬件设计。该系统的硬件部分主要包括报箱内的检测节点和用户住宅的用户节点,二者直接或以多跳方式通信。软件部分采用ColdWarrior进行编程,分别完成对报件到达检测并发送无线信号、接收报件到达数据或为上层楼层转发数据。设计实现了多层住宅信报箱报件到达检测与告知,避免了报件和信息延误。     

基于Web的数据采集和在线发布系统

随着电子政务、电子商务概念的提出及相关技术的发展,基于Web的数据采集和在线发布系统得到了越来越多的政府部门和企业的重视和认同。传统的数据采集系统往往是基于客户/服务器模式而设计的,这种系统存在着软件维护费用高、系统升级困难等诸多问题;同时在客户/服务器模式下的应用系统无法实现在线实时发布的功能。随着In-ternet的发展,有很多政府部门和企业实现了一些在线数据申报系统,而利用这些系统申报的数据量往往很小,在系统设计上相对简单。这种小型在线数据申报系统的设计思想往往不能够用于数据量庞大、界面复杂的大型应用系统的设计中;而目前国际上绝大多数在线发布系统中发布的文档格式是基于HTML的,同时在线发布的文档是利用网页设计软件手工编辑得到的,对于一些数据发布时效性强,数据发布量较大的应用环境来说,传统的文档生成模式不再适用。基于上海证券交易所上市公司定期报告数据采集和在线发布系统,笔者系统地介绍了对基于Web模式,同时数据采集量大,数据发布时效性强的中大型应用系统中数据采集和在线发布技术的研究,其中还涉及到一些相关技术的研究。     

发射率在线检测系统的上位机软件实现

针对发射率在线检测系统,提出了基于Visual C＋＋6.0编程平台,实现计算机对发动机辐射率实时数据采集及处理平台的上位机软件设计,并通过试验验证了本上位机软件的功能。该上位机软件通过串口与多台单片机进行通信,能够实现整个系统的数据采集、曲线显示、数据保存、历史数据读取、发射率计算等功能。上位机界面友好,能够实时显示测量结果并保存测量数据至Access数据库中,实现了数据的开放性、传输能力和测量仪器的人机交互性。     

Automated merging of software prototypes

As software becomes more complex, more sophisticated development and maintenance methods are needed to ensure software quality. Computer-aided prototyping achieves this via quickly built and iteratively updated prototypes of the intended system. This process requires automated support for keeping track of many independent changes and for exploring different combinations of alternative changes and refinements. This article formalizes the update and change merging process, extends the idea to multiple changes to the same base prototype, and introduces a new method of slicing prototypes. Applications of this technology include automatic updating of different versions of existing software with changes made to the baseline version of the system, integrating changes made by different design teams during development, and checking consistency after integration of seemingly disjoint changes to the same software system.     

DAVINCI.BYU: Engineering workstation management software

Computer software has been developed to take advantage of hardware advances in engineering workstations. A definition of the engineering workstation and its environment is given. Requirements of a good user interface is discussed and supporting software is described. A general workstation manager program is reviewed that provides a support layer between the user and the operating system, organizes software and data files, and facilitates on-line documentation and demonstrations.     

eLearniXML: Towards a model-based approach for the development of e-Learning systems considering quality

With the evolution of technology, and especially of the Internet, a growing interest has appeared for on-line education. The many advantages of e-Learning have made this teaching philosophy an ideal partner for teachers, either as a complement to regular education or as a substitute for traditional education. The development of an e-Learning system poses extra challenges for software developers, since there are other facets, such as contents and user tracking, not usually considered in software development methodologies. In this paper eLearniXML approach to the development of e-Learning systems is presented. This approach enriches the development of e-Learning systems method proposed in ADDIE with the model-based development of user interfaces and software quality consideration. By doing so, we aim at the development of, what we have named, a Model-Based Instructional Development Environment (MB-ISDE), to include e-Learning development in the current trends of model-based software development.     

A Product Data Management architecture for integrating hardware and software development

This paper proposes an architecture of Product Data Management (PDM) for integrating Software Configuration Management (SCM). The proposed architecture extends its data model to support version items for SCM. Its applications support both PDM and SCM functionalities, as well as integrate hardware parts and software items in product configurations and engineering change management. The architecture is implemented by using a commercial Product Lifecycle Management (PLM) system. The implementation enables hardware engineers and software programmers to share the same user environment, on a consistent database during the collaborative product development.     

网络软件自动升级技术剖析

文中剖析了采用Internet自动下载最新版本的软件升级编程机制，使软件的升级维护在客户端自动下载完成，非常方便快捷。     

Using spreadsheet to teach on-line statistical process control

This paper gives the design considerations for on-line statistical process control (SPC) using spreadsheet software. The system combines a data acquisition system, data translation board, spreadsheet package, and a microcomputer. The objective of this paper is to demonstrate, by means of examples, how a microcomputer spreadsheet software and a data translation board can be used to teach on-line SPC as an alternative to the expensive commercial SPC software. Moreover, in the training and education environment, computer simulated data can be used for different case studies. Experience in using this approach to teach on-line SPC will be described.     

ISP技术和双端RAM在开发高性能运动控制器中的研究

文章针对开发基于工业PC的国产高性能运动控制器,提出了采用ISP技术和双端RAM实现软件升级硬件和双CPU间高速数据交换。该系统结构解决了传统运动控制器执行速度慢,体积大、结构固定,硬件无法实现升级;用户的动态变量无法在线下载的缺点;从开发过程和使用效果来看:该设计有效缩短了开发周期,提高了数控系统硬件的质量,提出了运动控制器的新概念,运行结果表明系统完全达到了设计要求。     

INTELLIGENT SYNTAX-DIRECTED EDITOR THAT MODELS USER PROFICIENCY

Current interactive software systems try to offer many features and a user-friendly interface to aid the user. However, where one system may suit one user, another user may find it difficult to use, because each user is different. User modeling techniques have been applied to make a system suitable for different users. This paper surveys research works for developing interactive systems that use user modeling techniques. After presenting the systems and techniques, we introduce a system called the Intelligent Syntax-Directed Editor (ISE) as an example to show how this approach can benefit the user as an intelligent tool. The ISE assists the user in (1) using the editor more efficiently through ISE's active suggestions and on-line help and (2) program development through the syntax-directed editor. In applying user modeling techniques, ISE builds a profile/model of the user and, based on this model, ISE offers a suitable amount of help and advice depending on the proficiency of the user toward the system. The ISE is implemented on a VAX/780 computer to demonstrate its ability to volunteer advice