代码组件的组合重用是一种新的程序设计范型

本文在描述了程序设计范型的特性之后,详细地介绍了代码组件的组合重用方法,提出并论述了代码组件的组合重用是一种新程序设计范型的观点.本文还详细地描述了这种新程序设计范型的特点,同时也指出了应当解决的一些课题.     

基于组件技术的移动GIS应用软件的设计

随着通讯技术飞速发展,移动GIS将是地理信息系统应用的发展方向.本文提供了一种基于组件技术的移动GIS应用软件设计的体系结构.通过使用组件技术重新构建移动GIS系统结构,可以将复杂的移动GIS系统分解为具有特定功能的组件的集合.通过复用、集成具有各种功能的组件,可以快速开发出面向各种移动设备的GIS应用软件.     

移动计算形式理论分析与研究

移动计算是在网络技术发展中涌现出的一种新计算范型,文章旨在从形式抽象的角度来认识移动计算的本质特点,文中分析了网络计算平台的综合特征,总结了移动计算范型的曲型特征,重点介绍了有代表性的移动计算形式模型和方法,包括进程代数类的π－演算、环境演算和Ｓｅａｌ演算、时序逻辑类的移动Ｕｎｉｔｙ,以及Ａｃｔｏｒ扩充模型,针对每个模型或方法,分析了位置、移动等概念在模型中的刻画,以及各自的交互、动态配置重构和资     

面向控制器的实时组件技术研究

针对组件技术在控制系统设计中存在的建模问题、行为问题与定时问题 ,在系统的分析现有具有确定性行为组件技术的基础上 ,提出了实组件的概念 ,给出了一种面向控制器的实时组件模型 RTC,并对 RTC的结构、行为、通信、时态特性等方面进行了形式化的描述 .最后 ,以数控系统中运动控制的设计为例 ,验证了方法的有效性     

支持渐变过程的软件产品线框架的研究

产品线工程是一种正在出现的软件工程范型,用于开发相同领域的类似产品.在介绍了产品线框架相关的概念之后,根据产品线生命周期的特点,提出了框架从低级框架渐变为高级框架的过程,并在此基础上描述了框架元模型;为了支持从这种渐变,在组件库的基础上建立了视图机制,即原始映射视图、频繁组件项集视图和组件关联视图.这种基于组件库的视图机制,可以指导用户在框架实例化中的组件选取决策,促进了框架的成熟,提高了组件库的复用性能.     

基于组件的移动Agent平台设计与实现

将组件技术与移动Agent技术相结合可以有效地提高软件的重用性、灵活性及适应性,有利于大型分布式软件系统的开发.利用Javabean组件技术设计实现了一种移动Agent平台HBAgent,描述了HBAgent的设计思想和体系结构,给出了平台中的主要组件的概念,并通过一个应用实例说明了各组件的功能.该实例表明,HBAgent平台具有灵活、动态可扩充、支持离线计算等特点,可以为大型的应用开发提供一种面向Agent的开发平台.     

代码组件的组合重用是一种新的程序设计模型

本文在描述了程序设计范型的特性之后,详细地介绍了代码组件的组合重用方法,提出并论述了代码组件的组合重用是一种新程序设计范型的观点。本文还详细地描述了这种新程序设计范型的特点,同时也指出了应当解决的一些课题。     

河道横纵面绘制的组件设计及其应用

断面的绘制和分析在GIS应用系统设计与工程分析计算中常常用到,但可以被集成到应用系统中的断面组件却很少。本文介绍了基于ActivX组件设计方法的断面组件的设计方法、对象组成以及逻辑继承关系,并且介绍了断面组件设计中须注意的问题、断面数据的准备和断面绘制组件与其他GIS组件集成分析和绘制断面的方法。最后给出一个其在流域管理信息系统中的应用实例。     

移动P2P应用环境下的组件管理模型

描述了一个移动P2P应用环境下的组件管理模型P2PCOM(component in mobile P2P applications),P2PCOM支持非集中的网络结构,适合轻量级移动智能终端的P2P分布式应用开发.通过运用OSGi协议规范,提出端口管理器的概念,用来实现抽象的,灵活和高层次的通信机制.端口同时具有协议独立性、位置独立性、同步异步远程调用,组件中的服务可以在本地与远程的容器中迁移,根据QoS的需求,给服务定义服务等级.通过对实验场景的建立与实验性能分析,结果表明了P2PCOM可以较好的支持灵活的、高度可裁减的移动P2P应用开发.     

松耦合组件的通信模式研究

为了解决松耦合软件系统中的组件通信问题,对通知和消息队列通信模式中存在的同步耦合问题进行研究.通过分析组件通信的同步解耦问题,提出基于消息中心的通讯模式,并从通信方法、组件注册和消息队列3个方面进行说明.同时给出组件通讯地址编码方案,以及带有动态优先级的消息排队等待时间计算方法,并应用消息对解决了关联消息问题.结合多学科优化设计系统设计实践,验证该技术可行.     

志愿计算模型形式化方法

旨在从形式化抽象的角度来认识移动计算的本质特点.分析了志愿计算平台的特征,提出并分析了志愿计算中的3种角色以及志愿计算中资源和构件的概念,介绍了一种关于志愿计算的形式化模型和方法.对系统中的基本元素和交互关系进行了形式化的描述,并通过集合理论和操作规约,又以志愿计算平台XtremWeb为例,描述了构件化的志愿计算形式模型和方法,为系统地研究志愿计算形式化理论打下了基础.     

Automating the analysis of design component contracts

Software patterns are a new design paradigm used to solve problems that arise when developing software within a particular context. Patterns capture the static and dynamic structure and collaboration among the components in a software design. A key promise of the pattern‐based approach is that it may greatly simplify the construction of software systems out of building blocks and thus reuse experience and reduce cost. However, it also introduces significant problems in ensuring the integrity and reliability of these composed systems because of their complex software topologies, interactions and transactions. There is a need to capture these features as a contract through a formal model that allows us to analyze pattern‐based designs. In this paper, we provide an overview of a formal framework for ensuring the integrity of the compositions in object‐oriented designs by providing mathematically rigorous modeling and analysis techniques for object‐oriented systems comprising pattern‐based designs as the basic building blocks or design components. A case study related to a hypermedia Web‐based application has been presented to illustrate our approach in distributed systems. Copyright © 2005 John Wiley & Sons, Ltd.     

Reasoning about places, times, and actions in the presence ofmobility

The current trend toward portable computing systems (e.g., cellular phones, laptop computers) brings with it the need for a new paradigm to facilitate thinking about and designing distributed applications. We use the term mobile to refer to distributed systems that include moving, autonomous agents which loosely cooperate to accomplish a task. The fluid nature of the interconnections among components of a mobile system provides new challenges and opportunities for the research community. While we do not claim to have fully grasped all the issues involved in specifying and modeling such systems, we believe that the notions of place, time, and action will play a central role in any model that is developed. We show that these concepts can be expressed and reasoned about in the UNITY logic with a minimal amount of additional notation. The formal derivation of a control system for a radio-dispatched elevator is used to show how considerations involving place, time, and actions impact the design process, be it formal or semiformal     

On performance evaluation and design of atomic commit protocols for mobile transactions

The challenges of wireless and mobile computing environments have attracted the attention of researchers to revisit the conventional transaction paradigm. Indeed, this paradigm is an indispensable asset in modern information systems. The atomicity property of a distributed transaction is ensured with the use of an atomic commit protocol (ACP). Due to their great importance for transaction systems, the recent advances in mobile computing development have renewed the interest in the design of ACPs for mobile systems. The work presented in this paper studies the impact of the various and fluctuant parameters of wireless and mobile systems on a set of ACPs for mobile environment. It highlights performance indices which give orientations to the design of an adaptable approach that supports different atomicity notions satisfying a wide range of applications and environment requirements.     

面向Web服务的ERP协同集成框架研究

面向服务体系结构作为新一代分布式计算范式而成为研究企业应用集成这一领域的最新热点。但现有的工作尚未明确界定基于Web服务的ERP集成框架模型和实现机制。文章从企业分布式计算和XML技术发展融合的角度提出了一个新的基于Web服务的ERP协同集成框架。在给出Web服务形式化定义的基础上,对6层核心协议栈规范进行了扩充,定义了特定领域服务协同标识语言的基本元素,使协议规范不仅适用于Web服务,而且适用于企业内部的应用程序和应用程序内部组件的描述、发现和集成。建立了基于Web服务集成框架的支撑平台,并将该平台用于企业的整个ERP集成过程中。     

移动Agent系统中的安全问题和技术研究综述

移动Agent是分布式计算领域中一种新的计算模式。由于其在异步性、自治性以及移动性等方面的优势,移动Agent技术应用范围日益广泛,而随之而来的系统安全性问题也日益突出。拳文对移动Agent系统中的主要安全威胁做了细致的分析;在此基础上,从主机和Agent两技术方面以及社会角度总结了目前主要存在的安全保障措施;描述并比较了几种具代表性的移动Agent系统及各自的安全实现机制。     

间接计算模型和间接形式化方法

本文旨在从人机交互界面与协同计算程序结合而构成协同智能计算系统的角度,论述间接计算模型和间接形式化方法结合所支持的优化云计算技术原理。本文在系统回顾图灵可计算理论、克莱尼小字符串形式理论、冯诺依曼数字计算机体系结构和图灵人工智能判定假设等前人理论研究成果对主流数字计算机通用范式影响的基础之上,着重介绍了笔者设计的间接计算模型和大、小字符串兼容的问接形式化理论,并以中文信息数据为例介绍了协同智能计算系统原型的设计构想。其意义是该成果有利于从数据中心到知识中心优化云计算。     

Adaptation in mobile workflow management systems

Workflow management systems (WFMS) are an emerging technology for supporting the coordinated execution of business processes by a group of users. One goal of introducing a WFMS into an enterprise is to integrate all personnel working on a business process into the system. This article describes a new approach to the integration of mobile users into a WFMS. This is of special interest because key personnel such as sales representatives and executives are often travelling and can only be integrated into the WFMS through mobile computing technologies. After introducing an architecture for mobile WFMS, we focus on the handling of one specific feature of mobile systems: the high diversity of environments in which mobile users operate. For handling this feature we have to implement adaptable software systems. In our approach, we start by introducing a formal model of mobile systems. This model offers a basis for the use of optimisation techniques to realise an adaptive mobile WFMS.     

Moset: An anonymous remote mobile cluster computing paradigm

The advance of technology in terms of cellular communications and the increasing computing power of the mobile systems have made it convenient for people to use more of mobile systems rather than static systems. This has seen more of mobile devices in personal and distributed computing, thus making the computing power ubiquitous. The combination of wireless communication and cluster computing in many applications has led to the integration of these two technologies to emerge as Mobile Cluster Computing (MCC) paradigm. This has made parallel computing feasible on mobile clusters, by making use of the idle processing power of the static and mobile nodes that form the cluster. To realize such a system for parallel computing, various issues such as connectivity, architecture and operating system heterogeneities, timeliness issues, load fluctuations on machines, machine availability variations and failures in workstations and network connectivities need to be handled. Moset, an Anonymous Remote Mobile Cluster Computing (ARMCC) paradigm is being proposed to handle these issues. Moset provides transparency to mobility of nodes, distribution of computing resources and heterogeneity of wired and wireless networks. The model has been verified and validated by implementing a distributed image-rendering algorithm over a simulated mobile cluster model.