基于组件的软件系统可靠性评估的不确定性研究

当前一些基于体系结构的软件可靠性模型,在操作剖面和组件可靠性中,不管这些模型是否准确,只要有相当多的不确定性存在,在计算软件可靠性时,就会存在较多的不确定性.若采用传统方法估算软件的可靠性,忽略了属于参数不确定性存在的差异,那么结果可能不准确.提出了一种新的基于体系结构的不确定性的分析方法,该方法适合大型复杂的基于组件的应用程序及整个软件生命周期.     

基于组件的软件可靠性模型

首先对不同的软件体系结构描述语言（ADL）进行分析，找出体系结构的共性，用抽象代数和一代阶逻辑理论对组件，连接器和软件体系结构的属性和动态行为进行讨论和描述，探讨不同连接形式下的软件体系结构，给出基于组件的软件可靠性模型，在此模型基础上，对基于组件的软件系统的可靠性计算模型进行研究，提出一种半Markov模型，并在理论上证明该模型的可用性，最后通过CORBA应用系统说明该可靠性模型在系统设计和可靠性计算方面的应用。     

基于Petri网运行状态的组件化软件可靠性分析方法

通过分析软件系统的组件结构特征、运行状态和可靠性因素,提出了基于随机Petri试网运行状态的可靠性分析方法。对构成软件系统的各组件的可靠性进行分析和评估,根据系统运行状态动态跟踪软件的可靠性,推导出整个软件系统的可靠性。与仅着眼于系统组件间的执行路径不同,该方法更关注于系统各个运行状态的可靠性。最后给出了一个实例研究。     

基于Petri网运行状态的组件化软件可靠性分析方法

通过分析软件系统的组件结构特征、运行状态和可靠性因素,提出了基于随机Petri网运行状态的可靠性分析方法.对构成软件系统的各组件的可靠性进行分析和评估,根据系统运行状态动态跟踪软件的可靠性,推导出整个软件系统的可靠性.与仅着眼于系统组件间的执行路径不同,该方法更关注于系统各个运行状态的可靠性.最后给出了一个实例研究.     

基于体系结构的软件可靠性参数早期预测

在对组成软件系统的组件间关系进行分析的基础上,提出了基于组件间关系的软件可靠性的数学模型,该模型给出了在已知组件的可靠性和平均无故障运行时间的基础上计算系统可靠性的方法。通过各组件对系统可靠性的影响分析,给出了改善系统可靠性的方案。     

一种软件可靠性评估模型及其Petri网描述

通过提出k-可靠模型,对现有软件可靠性评估方法所依据的模型进行重构,并根据Petri网及软件可靠性的相关理论,对构成软件系统的各个组件进行可靠性评估,从而实现对软件系统的可靠性评估,并介绍一种自底向上的可靠性计算过程。该方法能对软件系统的进行分解和综合计算,达到对整个软件系统可靠性评估的目的。     

基于Java的网格计算框架及其实现

为了提高网格计算的可靠性,适应大规模计算的要求,采用了一种基于Java的分布式网格计算框架,它利用移动部署代理管理计算任务,可以最大限度地减轻中心主机的负担,并通过在Java运行环境中引入两个组件,解决了用Java构建网格计算时存在的安全和资源管理问题,是一种理想的基于Internet的网格应用项目,具有良好的实用性和推广价值。     

基于通信消息的云计算系统故障传播分析

云计算系统中,软件故障检测能够帮助提高各个组件以及整体系统的可靠性。该文提出了一种基于消息队列中的通信消息的故障检测方法。通过分析一般分布式系统的结构以及对OpenStack云计算平台进行故障注入,得到了云计算平台中软件故障传播的机理。实验结果表明基于通信消息能够有效的对云计算平台进行故障检测。     

基于框架技术的通用虚拟计算平台的实现

通过分析目前几种虚拟计算环境的现状、特点及适用范围,针对聚合异构分散计算资源的需求,提出了一种基于框架技术的虚拟计算环境的实现方法.研究了虚拟计算环境的关键实现技术,主要包括计算平台的总体框架和服务组件,以及各个组成部分之间的关系和通信方式;并基于服务分层设计方法来优化计算服务的架构,对各服务组件进行了详细的设计,实现了虚拟计算平台系统.以地震资料数据处理为例进行了实验测试,测试结果表明,该虚拟计算框架具有一定的可行性和有效性,能够整合零散、异构的计算资源,尤其适用于性能差异明显的计算组织,为用户提供了透明的资源访问模式,提高了计算资源的利用率.     

一种调和两种观点的安全协议分析法

在安全协议的形式化分析中，有两种完全不同的观点：符号方法和计算方法，两者各有优缺点．通过对两种观点的研究，按照优势互补的原则将两者相调和，建立了一种新的形式化分析方法．该方法将协议的安全性分为完全性和正确性，通过分析这两种性质，不仅能考察协议在逻辑上能否达到预期目标，而且能考察敌手在计算上的攻击能力．第一次从逻辑可靠性和计算可靠性两方面对协议进行了综合的安全性分析．     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate