基于行为协议的构件软件静态测试研究

系统的静态分析能在设计开发阶段发现错误,从而避免了在运行时错误检测技术在系统执行期间带来的负面影响.基于尽可能避免静态错误这一构件测试策略的基本思想提出了一种对构件化软件系统进行静态测试的方法.采用通信模型对数据库服务构件系统进行抽象建模,并结合用于描述构件系统中构件之间交互的形式化方法行为协议,通过对构件系统构件行为协议的一致性验证,从而测试构件交互的正确性.     

通用构件行为适应方法研究

基于构件的软件工程中,构件行为适应是一个关键的问题.目的是为了解决构件交互过程中由于行为不兼容而引起的各种不匹配问题.给出了解决构件行为不匹配的一种通用的方法.该方法首先根据给定的构件接口的行为协议描述计算构件行为之间的同步关系,得到适配器的描述.然后在构件的同步产品中,利用死锁来检测具有同步行为关系的行为之间的不匹配.利用构件及适配器描述计算同步矢量产品的过程中,根据同步矢量来计算适配器的行为协议,适配器通过一对互补事件与被适应构件进行交互.适配器适应交互的构件行为,使得构件交互过程中没有死锁发生.实现对消息顺序的重新排序,解决了具有数据传递的构件行为之间的不匹配问题.最后,用一个实例对文中所述方法进行了说明.     

面向测试的构件系统模型及测试用例生成方法

随着面向构件的软件开发方法的广泛应用,构件系统的描述和测试成为保证软件质量的关键所在。由于构件系统的复杂性和开发方法的特殊性,用传统方法对构件系统进行集成测试往往面对很多困难。提出了一种改进的面向测试的构件描述模型,称为TCSM,它着重对构件系统中的构件间的交互和约束进行了动态描述,为构件系统集成测试阶段的功能测试和边界测试等提供了大量可用信息。在此基础上,进一步提出一种把TCSM转换成测试模型的方法,以UML协作图模型为原型,实现了构件系统从描述模型到测试模型的自动转换。最后,实现了一种在所产生的测试模型上自动生成测试用例的算法。TCSM更好地描述了构件的交互行为信息,进一步实现了系统的自动化测试,减少了通常需要在构件系统搭建完成后,针对测试对系统手工建立测试模型的工作,提高了构件系统开发的效率和可靠性。     

构件行为协议实时性扩展及相容性验证

对复杂实时构件系统行为进行形式化描述和相容性验证,可以有效提高系统的正确性、可靠性。分析了学术界和工业界的主流构件模型及常见时间行为的形式化描述方法,对构件行为协议BP(Behavior Protocol)进行了扩展,提出了时间行为协议TbP(Timed Behavior Protocol),分析了构件组合中常见的相容性错误类型,给出了基于时间行为协议的构件组合相容性验证算法。TBP应用简洁、方便、易于验证。结合具体例子给出了应用示例。     

TCBV:一种构件时序行为建模与相容性验证工具

利用形式化方法对复杂实时构件系统的时序行为进行建模与验证对于提高安全攸关实时构件系统的正确性、可靠性与安全性具有重要意义。介绍了基于时间行为协议的构件时序行为的形式化建模和相容性验证方法,给出了时间行为协议建模与相容性验证工具TCBV的系统架构与功能模块。TCBV应用方便,能够实现实时构件时序行为模型的图形化表示,并可对复杂交互行为的相容性进行自动验证。结合应用实例,介绍了如何利用TCBV对复杂实时构件系统的时序行为进行建模和验证。最后,将TCBV与其它相关工具进行了比较。     

基于构件动态演化的行为一致性验证方法

为了保证构件在动态演化中的行为一致性,避免不合法的构件演化,提出一种基于进程代数的构件模型,引入对外主动请求接口和内部连接,形式化描述构件及其对外交互协议,给出相关定理和验证算法。实例证明,该构件模型可以验证动态演化中的接口兼容性、外部交互行为一致性,以及运行时行为完整性。     

包含协议和语义的构件一致性验证方法

在基于构件的系统设计中,需要对构件的一致性进行验证。构件的一致性包括语义一致性和协议一致性,已有的一致性验证方法仅支持构件的协议一致性验证。而在实际应用中除了要进行构件的协议一致性验证外,还需要进行其语义一致性验证。为此提出了一种包含协议和语义的构件一致性验证方法。所提方法将方法语义与基于场景的需求规约相结合,使用语义扩展接口自动机模型(SIA)来建模构件的语义和协议信息,使用带有语义约束的UML交互概观图来表示基于场景的需求规约。通过对SIA和带语义约束的UML交互概观图的行为的理论分析,进一步形成了一种一致性验证算法,并用实例来说明其过程。该算法不仅能够检验系统中构件的协议一致性,而且能够检验其语义一致性。该算法中的方法语义包括了该方法参数的类型和详细语义信息,更符合实际应用情形。     

面向对象范型体系结构中构件行为相容性研究

软件体系结构(SA)为基于构件的软件开发提供了一种高层次的抽象.如何有效描述体系结构中构件的对外交互行为、验证组装构件间的行为相容及保证整个体系结构行为无死锁是其中较为重要的研究内容.在基于面向对象范型这类重要的软件体系结构中,构件组装通常是通过接口方法调用加以实现.针对这样一类基于软件体系结构的构件组装问题,形式描述与定义了构件及其对外交互协议,分析了服务请求构件与服务提供构件所能展示的不同行为,给出了组装交互的构件在请求/提供接口上协议级行为相容的一组验证规则及相关定理.最后,通过一个电子商务应用实例来说明所提出途径的可用性和针对性.     

基于软件体系结构的测试及其工具研究

1 引言软件体系结构层测试的目的是找出体系结构的错误和缺陷,这与传统测试有很大的不同。SA测试分为体系结构的静态测试(即体系结构分析)和体系结构的动态测试(即体系结构模拟)两个方面。前者是对体系结构的静态行为特征进行分析,如各类一致性分析等;后者是对体系结构的动态行为特征进行模拟。 SA中的结构模式提供了一个设计和分析大型软件系统的自然框架,也为可重用的构件提供了组合成系统的规则。通过对软件体系结构的描述,使得复杂系统的测试与分析变得     

基于角色划分的构件组合兼容性检查

基于构件的软件开发是软件工程化和工业化发展的必然趋势,构件间通过接口实现交互。目前主要的接口定义语言是为了满足封闭的C/S应用而设计的,仅描述了构件交互的静态语法层信息,这些信息已不能满足开放环境下对构件理解、使用和推导需要。形式化方法因其描述的准确性和使用自动定理证明机制而受到越来越多的重视,以CORBA构件为例,结合一个电子商务应用实例,给出基于π演算的构件接口动态行为信息描述方法,在此基础上根据构件在交互中的作用进行了角色划分,并基于角色模型研究了构件组合中的兼容性问题,从而保证了开放环境下构件间成功地进行互操作。     

On the simulation of molded micro components and systems

Regarding micro components and systems, experimental work for characterizing materials’ properties as well as components’ and systems’ behaviors have to be supplemented by numerical analyses. These analyses should cover component and system issues. On a component level, macroscopic approaches are extended by methods allowing consideration of the influence of components’ grain structures including possible defects. On a system level, the high tolerances accepted for the individual components due to production inaccuracy and their effects on the expected load distribution capability of the system are taken into account. This paper presents approaches for simulation of micro components and systems using the finite element method and multi body simulation. Methods to overcome the abovementioned issues will be shown, as well as the effects of grain structure on the stress distribution in the individual components.     

Development with Off-the-Shelf Components: 10 Facts

Several empirical studies have been conducted on issues related to the development of systems using commercial off-the-shelf and open source software components. The results demonstrate a discrepancy between academic theory and industrial practices regarding the use of components. One reason is that researchers have empirically evaluated only a few theoretical methods; so, industrial practitioners have no reason to adopt them. Another reason might be that researchers have specified the application contexts of only a small number of theories in sufficient detail to avoid misleading users. Academic researchers often hold false assumptions about industry. For example, research on requirement negotiations often assumes that a client will be interested in, and be capable of, discussing a project's technical details. However, in practice this is usually not true. In addition, the quality of a component in the final system is often attributed solely to component quality before integration, ignoring quality improvements by integrators during component integration.     

业务流程驱动的森林仿真构件组装技术及应用研究

针对森林仿真系统的需求或应用目标不断发生变化的问题,提出了一种业务流程驱动的森林仿真构件组装方法。该方法设计和实现了森林仿真领域的构件模型和仿真构件接口,并通过业务流程驱动的构件组装框架实现了森林仿真系统的业务流程、模型算法等的软件复用,解决了现有森林仿真系统存在的快速构建或重构困难的问题。通过在虚拟森林仿真系统开发中的应用表明,基于构件组装的方法与代码级重用、重新开发方式相比,可以大幅减少开发工作量,降低系统的开发难度,实现森林仿真系统的快速搭建或重构。     

Integrated importance measures of multi-state systems under uncertainty

Importance analysis in reliability engineering is used to find the weakest components in a system. Traditional importance measures for multi-state systems analysis mainly pay attention to the reliability or structure characteristics of components, but seldom consider the causalities between components in the system under uncertainty. In order to solve the above problems, the multi-state system Bayesian network is proposed to represent the multi-state system under uncertainty and facilitate the component importance calculation. Then, this paper puts forward a separate subset algorithm based on the Bayesian information criterion and K2 algorithm to build the multi-state system Bayesian network of practical systems automatically. By considering the reliability, structure and causality characteristics of components comprehensively, the integrated importance measure is also presented to describe the effects of component failures on the state distribution of the multi-state system under uncertainty. Finally, the application of the multi-state system Bayesian network, the separate subset algorithm and the integrated importance measure in a simple head-up display system is implemented to verify the effectiveness of the proposed methods in components importance analysis.     

基于构件的信息系统体系结构模型

在分析信息系统层次结构的基础上，提出信息系统结构的层次化构件模型；描述了基于构件化层次模型的信息系统的抽象层次、结构元件、结构特征，给出了不同抽象粒度构件的形式化描述方法、构件连接的形式扣方法、基于企业模型的系统软件组织方式；为信息系统的设计与开发提供了参考模型。初步应用表明，层次化构件模型的设计思想架起了管理系统与信息系统之间的桥梁。提高了信息系统适应性扣开发效率。     

Built-In Contract Testing in Component Integration Testing

Assembling new software systems from prefabricated components is an attractive alternative to traditional software engineering practices which promises to increase reuse and reduce development costs. However, these benefits will only occur if separately developed components can be made to work effectively together with reasonable effort. Lengthy and costly in-situ verification and acceptance testing directly undermines the benefits of independent component fabrication and late system integration. This position paper outlines and introduces an approach for reducing manual system verification effort by equipping components with the ability to check their execution environments at run-time. When deployed in new systems, built-in tester components check the contract-compliance of their server components, including the run-time system, and thus automatically verify their ability to fulfill their own obligations. This comprises functional/behavioural contracts as well as quality-of-service contracts between individual components. Enhancing traditional component-based development methods with built-in contract testing in this way reduces the costs associated with component assembly, and thus makes the “plug-and-play” vision of component-based development closer to practical reality.     

Software control flow error detection and correlation with system performance deviation

Detecting runtime errors helps avoid the cost of failures and enables systems to perform corrective actions prior to failure occurrences. Control flow errors are major impairments of system dependability during component interactions. Existing control flow monitors are susceptible to false negatives due to possible inaccuracies of the underlying control flow representations. Moreover, avoiding performance overhead and program modifications are major challenges in these monitoring techniques. In this paper, we construct a connection-based signature approach for detecting errors among component interactions. We analyze the monitored system performance and examine the relationship of the captured error state parameters with the system performance deviation. Using the PostgreSQL 8.4.4 open-source database system with randomly injected errors, the experimental evaluation results show a decrease in false negatives using our approach relative to the existing techniques. It also demonstrates a significant ability of identifying the responsible components and error state patterns for system performance deviation.     

Methods for simulating and optimizing molded micro components and systems

Casting production of metallic and ceramic micro components is still in the research phase, and the components obtained with the current technologies are suffering of a certain lack of reproducibility. Within the scope of Collaborative Research Center 499 “Design, Production and Quality Assurance of Molded micro components made of Metallic and Ceramic Materials”, basics in a persistent process chain for micro components are acquired. The development, process preparation, mass production and material and components behavior investigation is understood under consistent chain. This work presents computer simulation based methods that contribute to optimize micro molded systems on both a component and a system basis. The introduction of such methods allows studying the behavior of components and systems with regard to their grain structure and the wide geometric tolerances required.     

Erratum to: New efficient method for dynamic modeling and simulation of flexible multibody systems moving in plane

Efficient, precise dynamic analysis for general flexible multibody systems has become a research focus in the field of flexible multibody dynamics. In this paper, the finite element method and component mode synthesis are introduced to describe the deformations of the flexible components, and the dynamic equations of flexible bodies moving in plane are deduced. By combining the discrete time transfer matrix method of multibody system with these dynamic equations of flexible component, the transfer equations and transfer matrices of flexible bodies moving in plane are developed. Finally, a high-efficient dynamic modeling method and its algorithm are presented for high-speed computation of general flexible multibody dynamics. Compared with the ordinary dynamics methods, the proposed method combines the strengths of the transfer matrix method and finite element method. It does not need the global dynamic equations of system and has the low order of system matrix and high computational efficiency. This method can be applied to solve the dynamics problems of flexible multibody systems containing irregularly shaped flexible components. It has advantages for dynamic design of complex flexible multibody systems. Formulations as well as a numerical example of a multi-rigid-flexible-body system containing irregularly shaped flexible components are given to validate the method.