支持上下文感知服务的中间件原型*

提出了基于传感器网络环境的上下文感知应用开发中间件原型的体系结构MidCASE,重点阐述了中间件的体系结构设计和软件运行时基于服务的分布式运行架构.讨论了上下文感知过程中的两个关键问题,包括上下文信息建立的方法和感知过程中上下文信息与高层通信的调度模型.最后,以该中间件原型为基础,通过在医疗护理的场景下实现上下文感知应用并证明了其易用性与支撑作用.     

基于反模式的J2EE中间件优化模型

针对反模式“细粒度远程调用”提出一种反模式检测模型,根据该检测模型提出基于反模式的J2EE中间件优化模型。在不中断应用系统的前提下,该优化模型能在中间件的辅助下支持在线重构,克服了离线重构模型修改客户端和不能自动重构的缺点。在企业资产管理系统中运用该模型,结果证明其在使系统其他属性不变的情况下,实现了自动在线重构,减少了开发人员的工作量。     

基于容器中间件的组件系统体系结构性能评价

对组件系统性能建模时,需要考虑中间件平台的影响.基于体系结构模式,分析了容器风格中间件对组件系统结构和性能的影响,并提出了一种在组件系统UML描述中集成中间件组件及交互关系的方法.从该集成UML模型导出的性能模型,能够有效地反映中间件的影响.这样,在对组件系统性能建模时,无须了解中间件内部细节.这种基于体系结构模式的方法可以方便扩展以处理不同风格的中间件,且易于实现自动化.以EJB容器中间件为例说明并验证了所提出方法的有效性.     

异构数据库集成中间件的研究与实现

为了解决企业网络环境中异构数据库的数据集成和共享问题,重点研究了如何利用XML技术屏蔽数据库间的异构数据难题.提出了基于XML和中间件的集成异构数据库数据源的框架模型,该模型主要实现两部分的功能:数据库信息映射字典的生成和中间件系统查询的运行.中间件系统以XML作为数据交换的中介,提出了关系数据库数据与XML文档相互转换的方法,实现了用户对异构数据库数据的透明化共享.该模型适合企业信息化建设的需要.     

中间件在数据库安全中的应用

提出了一种通过中间件技术对数据库信息的加密解决方案,针对数据库信息加密的一些特殊性,提出了相关加密定义和密文挪用方案,并将该中间件应用到数据库应用系统.     

基于软件体系结构的反射式中间件研究

Internet为分布应用提供了一种开放、动态的运行环境,这要求分布应用的主要基础设施中间件能够支持运行时查看并调整平台内部状态和行为,由此产生了反射式中间件.目前的反射式中间件研究与实践存在3个不足:注重系统局部或单个实体的反射而缺乏全局视图;注重中间件平台内部功能的反射,而对上层应用的反射不够;集中于CORBA平台,而对J2EE平台的反射性研究较少.介绍了一个反射式的J2EE应用服务器PKUAS.基于构件化的平台内部体系结构,PKUAS引入软件体系结构作为全局视图以实现反射体系对系统整体的表示和控制,作为J2EE应用服务器,PKUAS可反射底层平台以及上层EJB构件.同时,以PKUAS实时监控工具为例,探讨了如何利用基于软件体系结构的反射体系管理整个系统,并给出了PKUAS与其他几种反射式中间件的比较.该工作有效地解决了现阶段反射式中间件研究的不足,提高了反射式中间件的实用性.     

中间件技术在移动增值领域的设计与实现

中间件是构件化软件的一种表现形式,中间件抽象了典型的应用模式.以一个移动增值平台为例,阐述构件化中间件系统的基本技术及在移动增值领域的应用.通过移动中间件在实际应用系统的具体设计与模块实现,设计一种基于数据库为中介的通用移动增值服务平台,并具体分析中间件满足快速开发和增强系统稳定性的优点,以及在增值领域开发还需要关注的问题.阐述了用移动中间件建立通用移动增值服务系统的必然性.     

基于中间件和Web Services的企业应用集成方法应用研究

在企业的信息化发展过程中.形成的"信息孤岛"已成为现代企业信息共享的一个制约因素.论文对当前企业应用集成的需求、方法及存在的问题进行了分析和讨论,通过结合中间件技术和Web Services技术特点,探讨了一个基于中间件技术的企业应用集成框架.该集成框架以中间件系统为核心构建分布式应用平台,克服了传统应用集成方法的不足,有效地解决了企业内部的跨平台应用间的集成问题,并为企业发展电子商务提供支持.     

基于TUXEDO的数据综合服务平台实现

本文首先介绍了中间件的基本概念,重点介绍了交易中间件BEA Tuxedo。结合笔者所参与的应用项目实例,对传统C/S模式下实现的系统与三层架构C/S模式下实现的系统进行了性能比较。简单介绍了利用Tuxedo的开发过程,实现了基于Tuxedo的一个数据综合服务平台,并对该平台的性能进行了评估,突出了中间件Tuxedo在系统开发中的重要作用。     

基于嵌入式系统的RFID中间件设计

针对嵌入式系统的特点,研究了轻量级的嵌入式RFID中间件ERM的体系结构。在ERM体系结构指导下,实现了运行于嵌入式平台的RFID中间件。该中间件体积小、功耗低、占用资源少、性能高,能够满足食品溯源系统的应用需求。     

Specification of behavioral anti-patterns for the verification of block-structured Collaborative Business Processes

Context: The verification of the control flow of a Collaborative Business Process (CBP) is important when developing cross-organizational systems, since the control flow defines the behavior of the cross-organizational collaboration. Behavioral anti-patterns have been proposed to improve the performance of formal verification methods. However, a systematic approach for the discovery and specification of behavioral anti-patterns of CBPs has not been proposed so far.Objective: The aim of this work is an approach to systematically discover and specify the behavioral anti-patterns of block-structured CBP models.Method: The approach proposes using the metamodel of a CBP language to discover all possible combinations of constructs leading to a problem in the behavior of block-structured CBPs. Each combination is called minimal CBP. The set of all minimal CBPs with behavioral problems defines the unsoundness profile of a CBP language, from which is possible specifying the behavioral anti-patterns of such language.Results: The approach for specification of behavioral anti-patterns was applied to the UP-ColBPIP language. Twelve behavioral anti-patterns were defined, including support to complex control flow such as advanced synchronization, cancellation and exception management, and multiple instances. Anti-patterns were evaluated on a repository of block-structured CBP models and compared with a formal verification method. Results show that the verification based on anti-patterns is as accurate as the formal method, but it clearly improves the performance of the latter.Conclusion: By using the proposed approach, it is possible to systematically specify behavioral anti-patterns for block-structured CBP languages. During the discovery of anti-patterns different formalisms can be used. With this approach, the specification of anti-patterns provides the exact combination of elements that can cause a problem, making error correction and result interpretation easier. Although the proposed approach was defined for the context of CBPs, it could be applied to the context of intra-organizational processes.     

一种中间件服务容错配置管理方法

提出一种基于运行时刻软件体系结构的容错管理方法,支持开发者和管理员针对不同中间件服务失效定制合适的故障检测和修复机制.首先,运行时刻软件体系结构自动构造构件依赖视图和错误传播①视图,为理解和分析整个系统的可靠性提供全局视图;然后,操作运行时刻软件体系结构配置容错机制;最后利用AOP技术将容错机制插装到中间件中,使其具备指定的容错能力.上述过程在一个可视化工具的辅助下半自动实施,并在J2EE中间件上得到验证.     

Online approach to feature interaction problems in middleware based system

As a popular infrastructure for distributed systems running on the Internet, middleware has to support much more diverse and complex interactions for coping with the drastically increasing demand on information technology and the extremely open and dynamic nature of the Internet. These supporting mechanisms facilitate the development, deployment, and integration of distributed systems, as well as increase the occasions for distributed systems to interact in an undesired way. The undesired interactions may cause serious problems, such as quality violation, function loss, and even system crash. In this paper, the problem is studied from the perspective of the feature interaction problem （FIP） in telecom, and an online approach to the detection and solution on runtime systems is proposed. Based on a classification of middleware enabled interactions, the existence of FIP in middleware based systems is illustrated by four real cases and a conceptual comparison between middleware based systems and telecom systems. After that, runtime software architecture is employed to facilitate the online detection and solution of FIP. The approach is demonstrated on J2EE （Java 2 Platform Enterprise Edition） and applied to detect and resolve all of the four real cases.     

面向性能的软件再工程研究

将提高遗产系统性能作为软件再工程的一大目标加以考虑，提出了一种基于反模式的再工程方法。这种方法通过对一些反模式的特征进行识别，在遗产系统中发现对于系统性能有不良影响的设计并通过一定的方法加以消除，从而达到改善遗产系统性能的目的。     

An approach to enhance the efficiency of opportunistic grids

Opportunistic grid computing middleware has as a main concern the need to preserve the performance of the local applications running on machines that donate resources to the grid. This concern, together with the fact that it happens in an extremely dynamic environment, causes the adoption of a treatment based on thetextitbest‐effort principle for grid applications. This means that efficient application management schemes are usually not employed, which results in less than optimal performance as grid applications often need to be restarted due to (often temporary) resource claims by local user applications. This paper presents a method to improve the performance of grid applications, taking into account resource usage profiles for local applications, trying to identify when such resource claims are temporary and avoiding costly actions such as the migration of grid tasks. The approach is proposed as an extension to the InteGrade middleware and its evaluation shows promising results for the efficient management of grid applications. Copyright © 2011 John Wiley & Sons, Ltd.     

Software project management anti-patterns

This paper explores the area of bad practices, namely anti-patterns, and their consequences in software project management (SPM). The paper surveys the multitude of anti-patterns that have been reported and documented up to now and stresses the need for tools to formally represent SPM anti-patterns, proposing specific formalisms for such purpose, namely Bayesian Belief Networks, Ontologies and Social Networks. It is also explained how the Web can provide an opportunity for capturing, storing, disseminating and ultimately avoiding SPM anti-patterns. As a consequence, anti-patterns may provide an excellent tool for educating active and future software managers. Finally, conclusions and future research trends are given.     

Don’t do this – Pitfalls in using anti-patterns in teaching human–computer interaction principles

This paper explores the use of design patterns and anti-patterns in teaching human–computer interaction principles. Patterns are increasingly popular and are seen as an efficient knowledge transfer mechanism in many fields, including software development in the field of software engineering, and more recently in the field of human–computer interaction. In software engineering a concerted effort is also being made to identify and document anti-patterns for recording the experiences of expert software developers to caution novices against potential bad practices. It is, however, essential that we ensure compatibility with the learner’s internal knowledge representation and acquisition processes, whether we are attempting to convey the knowledge in the form of a pattern or an anti-pattern. Since teaching with anti-patterns implies using negation, the primary aim of the research reported in this paper is to explore the efficacy of negative, rather than positive, teaching mechanisms. Evidence from theories of mental modelling and knowledge acquisition that highlight significant dangers in the use of anti-patterns to teach novices human–computer interaction principles is presented and supported with empirical findings. We started off by investigating the use of patterns (positive) in teaching, and then carried out experiments to test the use of anti-patterns (negative) in teaching HCI principles. This paper, whilst reporting mainly on our findings with respect to HCI design anti-patterns, will also identify some problems with the structure and use of patterns and anti-patterns in pedagogy.     

Middleware for Internet of Things: Survey and Challenges

The Internet of things (IoT) applications span many potential fields. Furthermore, smart homes, smart cities, smart vehicular networks, and healthcare are very attractive and intelligent applications. In most of these applications, the system consists of smart objects that are equipped by sensors and Radio Frequency Identification (RFID) and may rely on other technological computing and paradigm solutions such as M2M (machine to machine) computing, Wifi, Wimax, LTE, cloud computing, etc. Thus, the IoT vision foresees that we can shift from traditional sensor networks to pervasive systems, which deliver intelligent automation by running services on objects. Actually, a significant attention has been given to designing a middleware that supports many features; heterogeneity, mobility, scalability, multiplicity, and security. This papers reviews the-state-of-the-art techniques for IoT middleware systems and reveals an interesting classification for these systems into service and agent-oriented systems. Therefore two visions have emerged to provide the IoT middleware systems: Via designing the middleware for IoT system as an eco-system of services or as an eco-system of agents. The most common feature of the two approaches is the ability to overcome heterogeneity issues. However, the agent approach provides context awareness and intelligent elements. The review presented in this paper includes a detailed comparison between the IoT middleware approaches. The paper also explores challenges that form directions for future research on IoT middleware systems. Some of the challenges arise, because some crucial features are not provided (or at most partially provided) by the existing middleware systems, while others have not been yet tackled by current research in IoT.     

基于中间件的系统开发过程及实例分析

为了解决网络环境中的应用系统必须具备的能在异构平台上运行的能力,中间件(mid-dleware)就能做到这一点。讨论了基于中间件的分布式系统的开发过程以及主流技术的发展。给出了一个实例进行系统分析。