Synthesis of decentralized and concurrent adaptors for correctly assembling distributed component-based systems

Building a distributed system from third-party components introduces a set of problems, mainly related to compatibility and communication. Our existing approach to solve such problems is to build a centralized adaptor which restricts the system’s behavior to exhibit only deadlock-free and desired interactions. However, in a distributed environment such an approach is not always suitable. In this paper, we show how to automatically generate a distributed adaptor for a set of black-box components. First, by taking into account a specification of the interaction behavior of each component, we synthesize a behavioral model for a centralized glue adaptor. Second, from the synthesized adaptor model and a specification of the desired behavior that must be enforced, we generate one local adaptor for each component. The local adaptors cooperatively behave as the centralized one restricted with respect to the specified desired interactions.     

基于变更模型的元数据在构件回归测试中的应用研究

本文针对Orso元数据方法的不足,对构件可能的变更进行了充分分析和分类,并按照分类情况对相关的构件变更处理方法进行了详尽的形式化描述,构造了构件变更模型,描述了每个变更的具体表现形式,论述了方法变更到构件接口变更的映射机制和算法,给出了算法实现的框架,并将这些理论模型应用到自主开发的构件RegisterStuGrade中,与没有元数据情况下的回归测试用例生成技术以及Orso方法进行回归测试用例数和回归测试运行时间两方面的分析和对比,给出了比较结果.     

Failure-free coordinators synthesis for component-based architectures

One of the main problems in component assembly is how to establish properties on the assembly code by only assuming a limited knowledge of the single component properties. Our answer to this problem is an architectural approach in which the software architecture imposed on the assembly prevents black-box integration anomalies. The basic idea is to build applications by assuming a “coordinator-based” architectural style. We, then, operate on the coordinating part of the system architecture to obtain an equivalent version of the system which is failure-free. A failure-free system is a deadlock-free one and it does not violate any specified coordination policy. A coordination policy models those interactions of components that are actually needed for the overall purpose of the system. We illustrate our approach by means of an explanatory example and validate it on an industrial case study that concerns the development of systems for safeguarding, fruiting, and supporting the Cultural Heritage.     

Enforceable component-based realtime contracts

We present enforceable component-based realtime contracts, the first extension of component-based software engineering technology that comprehensively supports adaptive realtime systems from specification all the way to the running system.To provide this support, we have extended component-based interface definition languages (IDLs) and component representations in repositories to express realtime requirements for components. The final software, which is assembled from the components, is then executed on a realtime operating system (RTOS) with the help of a component runtime system. RTOS resource managers and the IDL-extensions are based on the same mathematical foundation. Thus, the component runtime system can use information expressed in a component-oriented manner in the extended IDL to derive parameters for the task-based admission and scheduling in the RTOS. Once basic realtime properties can thus be guaranteed, runtime support can be extended to more elaborate schemes that also support adaptive applications (container-managed quality assurance).We claim that this study convincingly demonstrates how component-based software engineering can be extended to build systems with non-functional requirements.     

Utility and accuracy of smell-driven performance analysis for end-user programmers

This paper proposes a technique, called smell-driven performance analysis (SDPA), which automatically provides situated explanations within a visual dataflow language IDE to help end-user programmers to overcome performance problems without leaving the visual dataflow paradigm. An experiment showed SDPA increased end-user programmers’ success rates at finding performance problems and decreased the time required for finding solutions. Another study, based on using SDPA to analyze a corpus of example end-user programs, revealed that it is usually accurate at identifying performance problems. Based on these results, we conclude that SDPA provides a reliable basis for helping end-user programmers to troubleshoot performance problems, as well as a potential foundation for future work aimed at training users and at aiding code reuse.     

An editing tool that manages device associations in an in-home environment

The forthcoming home environment will comprise numerous computationally enhanced artifacts that are autonomous, but interconnected via an invisible web of network-based services. The approach presented in this paper is to enable end users to make their own applications by linking such artifacts, which are treated as reusable components. A key requirement to achieve this is the availability of editing tools that meet the needs of different classes of users. A tool of this kind designed for end users is presented in this paper, together with the outcome of user evaluation sessions.     

嵌入式软件中一种修正QoS值的构件选择方法

CBSD(Component-Based Software Development)已经成为嵌入式软件开发的主流技术。在嵌入式环境下,有大量功能相似的构件,在开发过程中基于QoS的构件选择已成为研究热点。然而这些构件的QoS声明与提供者给出的往往并不一致。为此,提出一种基于修正QoS值的构件选择方法,该方法将QoS信任度作为权重,修正QoS值,再结合模糊逻辑,推理出该构件的综合服务能力。通过嵌入式VOD仿真实验,验证了算法的有效性,保证了构件选择的客观性和准确性。     

Integrated model for software component selection with simultaneous consideration of implementation and verification

One important objective of component-based software engineering is the minimization of the development cost of software products. Thus, the costs of software component implementation and verification, which may involve substantial expenses while under development, should be reduced. In addition, the costs for these processes should not be considered individually, but in an integrated manner, to further reduce development cost. In the current paper, an integrated decision model is proposed to assist decision-makers in selecting reuse scenarios for components used for implementation and in simultaneously determining the optimal number of test cases for verification. An objective of the model is the minimization of development cost, while satisfying the required system and reliability requirements. The Lagrange relaxation decomposition (LRD) method with heuristics was developed to solve integrated decision problems. Based on LRD, the nonlinear model is condensed into a 0–1 knapsack problem for the subproblem on reuse scenario selection and an integer knapsack problem for the subproblem on the determination of the optimal number of tests. Combined with the Lagrange multiplier-determined heuristic, the proposed algorithm can determine the global optimum solution. Simulations of varying sizes for problems and sensitivity analyses were conducted, and the results indicate that LRD is more effective than previous methods in determining global optimal solutions for the integrated decision problem.     

软件动态配置模型中的构件依赖描述

构件间的依赖关系是当前基于构件的分布式软件的研究热点之一.提出一种基于XML的描述构件间依赖的方法,并将该方法应用于一个动态配置分布式软件的模型中,成功地实现了构件的动态配置和部署,证明了该方法的可行性.     

面向方面软件体系结构建模研究

用面向方面编程思想研究软件体系结构,提取体系结构中的横切属性,并以方面连接件的形式对其进行建模,然后提出基于UML的面向方面体系结构元模型,最后通过图书管理系统实例说明具体建模过程,对传统体系结构模型和面向方面体系结构模型进行比较分析,结果表明了面向方面软件体系结构模型具有更高的实际应用价值.     

构件软件变更风险分析技术

构件软件相较于传统软件系统有更快的演化速度,对其变更进行有效的度量将有利于后期的维护活动.本文分别针对代码可见及不可见两种类型的构件,运用改进的构件依赖图建模,表示构件软件系统.分两步分析构件变更所带来的风险:首先在计算变更比例的基础上度量单个构件的变更风险,再通过将构件依赖图转化成构件依赖树来计算变更的构件集给系统所带来的风险.此外,结合实例系统的分析给出了所提出的变更风险度量的若干性质.     

A case study on expressiveness and performance of component-oriented parallel programming

Component-oriented programming has been applied to address the requirements of large-scale applications from computational sciences and engineering that present high performance computing (HPC) requirements. However, parallelism continues to be a challenging requirement in the design of CBHPC (Component-Based High Performance Computing) platforms. This paper presents strong evidence about the efficacy and the efficiency of HPE (Hash Programming Environment), a CBHPC platform that provides full support for parallel programming, on the development, deployment and execution of numerical simulation code onto cluster computing platforms.     

CBSD方法在机场信息系统中的应用

简述了基于构件的软件开发（Component-Based Software Development:CBSD)方法研究的内容和发展现状，分析了机场领域中信息系统的需求，给出了机场领域信息系统的3种软件体系结构，并采用CBSD方法实现了本系统的部分功能。     

构造基于构件依赖关系矩阵的元数据模型

构件集成到应用环境中实施集成测试时,会与其它构件产生相应的依赖关系.本文在对这些依赖关系进行概述的基础上,给出了构件直接依赖图、构件间接依赖图和构件依赖图的定义,并依据这些定义,提出了构件依赖矩阵(CmDM)的概念,用以描述构件Cm与构件系统中其它构件之间的依赖关系,接着进一步定义了复杂依赖关系矩阵(CmDDM),用以对依赖关系矩阵(CmDM)进行更为详细的描述.对依赖矩阵方法在回归测试、构件变更处理和软件重用的应用方法进行了形式化的描述,进一步将基于依赖关系矩阵的方法应用于学校内部开发的构件RegisterStuGrade 中,并另外选取了三个与之有关的构件,对其依赖关系进行分析,建立相应的构件依赖关系矩阵和复杂依赖关系矩阵,并与Orso方法、Spec方法(基于规范说明的方法)所生成的测试用例对于构件RegisterStuGrade源代码的覆盖情况进行了对比,从而证明了本方法的有效性.     

基于Ontology的数字博物馆通用建设平台研究

本文以Ontology技术为基点,结合Web服务技术的优点,设计了允许最终用户编程的数字博物馆通用建设平台,构建了文博业务领域本体和Web服务本体来支撑用户文博业务需求与Web服务间关联匹配.避免了传统数字博物馆建设中的重复开发及耗资大、周期长等缺点,并为其它领域通用建设平台的构建提供了参考.     

The Palladio component model for model-driven performance prediction

One aim of component-based software engineering (CBSE) is to enable the prediction of extra-functional properties, such as performance and reliability, utilising a well-defined composition theory. Nowadays, such theories and their accompanying prediction methods are still in a maturation stage. Several factors influencing extra-functional properties need additional research to be understood. A special problem in CBSE stems from its specific development process: Software components should be specified and implemented independently from their later context to enable reuse. Thus, extra-functional properties of components need to be specified in a parametric way to take different influencing factors like the hardware platform or the usage profile into account. Our approach uses the Palladio component model (PCM) to specify component-based software architectures in a parametric way. This model offers direct support of the CBSE development process by dividing the model creation among the developer roles. This paper presents our model and a simulation tool based on it, which is capable of making performance predictions. Within a case study, we show that the resulting prediction accuracy is sufficient to support the evaluation of architectural design decisions.     

基于构件的敏捷软件开发方法

软件在规模、复杂度、功能上的极大扩展和提高,以及在需求和技术上不断变化的过程中实现快速软件开发的要求,使得众多现有的软件开发方法不能很好地满足实际的开发需要,该文有效地结合了基于构件的软件开发和敏捷开发方法,提出了软件开发的一种新方法一基于构件的敏捷软件开发方法,并成功地进行了实践。     

Computer vision for human modelling and analysis

This report summarises the author's views and experience on the application of computer vision technology for the modelling and analysis of people. The author conducted research which led to the first commercial booth system for capturing animated models of people for applications in games, multimedia and virtual reality. This research is ongoing with the aim of developing studio capture technology to enable photo-realistic capture of a person's shape, appearance and movement for broadcast production.Published online: 8 August 2003     

接口连接式构件组装的一种形式化方法

构件组装是基于构件的软件开发的研究重点之一,能够有效地提高软件开发的效率和质量。以往大部分构件组装技术是在“成功组装路线”的前提条件下实现的,缺乏对构件组装正确性的检验。本文改进了常用的接口连接式构件组装技术,采用形式化方法描述和推导与构件以及构件组装相关的问题,给出了映射算法,实现了从构件组装规约向粘合代码的自动转换,为构件组装形式化分析、组装正确性检验提供了保证。     

一种图形化的CORBA体系结构描述方法

随着软件技术的发展,对于软件体系结构的研究越来越引起人们的重视。本文对CORBA分布式软件体系结构的描述需求和组件之间的依赖关系进行了较详细的分析,在此基础上提出了一种基于图形的软件体系结构描述方法,该方法把基于CORBA的分布式应用的软件体系结构视为一张逻辑图,在图上预定义一组操作,有助于CORBA应用的程序设计和维护。本文还在CORBA之上实现了一个原型,概括地介绍了具体的实现途径。