状态图到PTL形式规范的转化

本文讨论从状态图到PTL形式规范的转化方法.状态图是描述系统行为的半形式化的图形工具,但缺少精确的形式语义,PTL(投影时序逻辑)是一种具有离散的时间模型的时序逻辑,把状态图转换到PTL后可以使其具有精确的形式语义并能使用形式化验证方法来证明状态图所描述的系统的一些重要性质是否得到满足,同时可把系统的形式描述转换为Tempura程序进行模拟,从而提高系统设计的可信性.     

良基归纳法在时序逻辑程序不变式验证中的应用

并发程序的不变式验证对理解程序和提高程序的正确性具有重要意义.以一种区间时序逻辑程序设计语言Framed Tempura为研究对象,给出了该语言的等价正则形,定义了该正则形在相邻两个状态上的良基关系,进而利用良基归纳法原理对该语言所描述的系统的不变式进行归纳验证.提出的基于良基归纳法的验证方法在时序逻辑程序中可以方便地验证系统的不变式,尤其是循环结构的不变量性质.     

时间区间时序逻辑的判定性与表达能力

模型检测技术在实时系统验证中被广泛使用。离散时间区间时序逻辑满足性是可判定的,因而也是可模型检测的。连续时间域时间区间时序逻辑是否可模型检测,则并不清楚。约束时间域到非负实数,证明了其可满足性是不可判定的,但存在该逻辑的可判定子集,并发现了这样的子集。由于模型检测问题可归约为时序逻辑满足性判定问题,因此结果表明,时间区间时序逻辑不可模型检测,但其可判定子集可模型检测。     

WISHBONE片上总线符号模型检测

随着多核体系结构的出现和普及,片上总线逐渐成为影响片上系统功能和性能的关键部件.因此,片上总线的验证成为片上系统设计中一个重要组成部分.模型检测作为一种主流的形式化验证方法,可以自动化穷举搜索系统行为以决定片上系统的设计是否满足设计规范.然而,模型检测受制于状态空间爆炸问题,且现有规范语言如计算树逻辑和线性时序逻辑等的描述能力有限.提出了一种基于命题投影时序逻辑的WISHBONE片上总线符号模型检测方法.该方法将以Verilog硬件描述语言实现的WISHBONE总线转化为以NuSMV模型检测工具的建模语言SMV描述的系统模型,使用命题投影时序逻辑描述WISHBONE总线期望的性质,通过PLSMC工具验证系统模型是否满足期望的性质.实验结果表明该方法能够有效验证WISHBONE片上总线的定性性质,以及时间敏感和迭代性等定量性质.     

基于命题投影时序逻辑的单调速率调度算法模型检测

提出了基于命题投影时序逻辑(propositional projection temporal logic,简称PPTL)的单调速率调度(rate monotonic scheduling,简称RMS)模型检测方法.该方法使用SPIN模型检测器的系统建模语言PROMELA为任务调度系统建模,使用PPTL描述系统期望的性质,通过SPIN验证系统模型是否满足性质,从而得知一个任务组在RMS下是否可调度.同时,RMS算法控制下的任务调度系统的其他性质也可以得到验证.     

程序时序属性的自动测试

测试预言是一种用来检测被测系统的测试执行是否正确的方法。文中，作者设计并实现了一种根据程序的线性时序逻辑(LTL)的性质产生测试预言的方法。首先，作者将一线性时序逻辑公式转换为一个有限状态自动机，然后，管理源代码，以便抽取与线性时序逻辑性质有关的状态序列。最后，用谊信息来模拟状态自动机，并决定程序执行是否满足线性时序逻辑的性质。     

一种基于并发命题投影时序逻辑模型检测的入侵检测方法

基于投影时序逻辑模型检测的入侵检测方法具有描述网络入侵者分段攻击的能力,然而对并发攻击仍无能为力,因为该逻辑无法直接描述并发。针对此问题,在该逻辑的基础上定义了一种新的并发算子,并给出基于并发投影时序逻辑模型检测的入侵检测方法。对复杂攻击实例的检测表明,新方法可有效提高对并发攻击的检测能力。     

分布式软件系统交互行为建模、验证与测试

为了确保分析与设计阶段分布式软件系统中模块之间交互行为的正确性,提出了一种分布式软件系统模块交互的抽象方法,分别通过系统状态机图和对象状态机图对各模块状态变迁进行建模,使用UML2．0序列图对模块之间交互行为进行描述．采用基于命题投影时序逻辑的模型检测技术,将对象状态机图转换为 Promela 模型,系统交互性质转换为命题投影时序逻辑公式,通过模型检测器验证交互模型是否满足于系统的性质,若不满足于该性质,则能够获得反例执行的路径．给出了一个分布式软件系统测试框架,在验证后的序列图模型基础上,使用基于模型的测试用例自动生成方法得到测试用例集合,该集合能够实现对交互行为的有效测试．实例结果表明,该方法可以提高分布式软件系统中模块交互行为的有效性和可靠性．     

一种基于投影时序逻辑模型检测的入侵检测方法

基于时序逻辑模型检测的入侵检测技术降低了误用检测的漏报率,然而却几乎不能描述并发攻击和分段攻击,因而对这些复杂的攻击模式漏报率仍很高。本文针对该问题,提出了一种基于投影时序逻辑模型检测的入侵检测方法。对若干复杂攻击实例的检测表明,新方法可有效降低对并发攻击和分段攻击的漏报率。     

一种基于Büchi自动机的LTL程序模型检测方法

时序逻辑程序的形式化验证对提高程序的正确性具有重要意义。基于自动机的理论,用标签转移系统（S）表示程序的行为,用时序逻辑公式（F）描述程序的性质,构建相应的Büchi自动机,从而证明形式化公式SF是否可满足。     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

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.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

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.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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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.