基于三值语义的软件运行时验证方法

运行时验证技术是对传统的程序正确性保证技术如模型检验和测试的有效补充。模型检验和测试都试图验证系统的所有可能执行路径的正确性,而运行时验证关注的是系统的当前执行路径。本文提出一种基于三值语义的软件运行时验证方法,一方面该方法提供了从代码插装、系统底层信息提取到监控器生成、验证系统运行轨迹是否满足性质规约的完整的解决方案;另一方面基于三值语义的监控器有发现一条无穷运行轨迹的最小好(坏)前缀的能力,从而使得监控器能尽可能早的发现性质违背。同时,我们开发了基于三值语义的软件运行时验证原型工具并针对案例进行了分析。     

面向组合式软件功能正确性和非功能满足性的统一建模方法

在Internet动态、开放、异构、多变的环境下,组合式软件不仅要满足功能正确,非功能(时间、代价、概率等)属性的满足也日益成为一个重要的问题。在组合式软件的设计阶段,建立组合式软件功能和非功能的统一模型并验证其功能正确性和非功能满足性,是确保组合式软件可信性的重要手段。在UML序列图的基础上进行时间、代价、概率属性的扩展,提出了一种可对组合式软件的交互行为及其时间、代价、概率属性统一建模的属性序列图,该属性序列图以两层模式进行建模,其中基本属性序列图可对涉及时间、代价属性的具体交互场景建模,高层属性序列图通过概率合成基本属性序列图可形成全局场景。给出了针对BPEL4WS的建模实例以说明所提建模方法的有效性。     

逆向工程中动态剧情的多重抽象方法研究

动态信息是目标系统运行时行为特征的表现.从对软件的动态行为的可读视图(序列图)中,可以抽取出系统高层的动态模型,展示目标系统的高层体系结构.针对逆向自动生成的序列图,引入了多种对序列图的分割和抽象方法,帮助用户从不同的层次和不同关注点来分析动态信息,理解系统的动态行为.     

基于AADL的软件重构工具设计与实现

模态(Mode)表示的是软件可操作配置的状态,在一个或多个模态内可对资源和属性进行重新配置,即重构。目前,在对VxWorks系统下C程序的AADL架构进行模态的提取和蓝图制定过程中,还没有现成的工具。因而,设计一个基于AADL架构的软件重构工具将给软件架构的重构提供更大的帮助。为了搭建起基于AADL架构的软件重构可扩展工具平台,在Eclipse开源开发环境下,设计了SRM2( Software Reconfiguration Middlcware based on Mode)插件工具。SRM2工具主要完成对C程序的AADL架构的扫描进而描述程序架构的静态蓝图信息,以及结合代码(探针设计和植入)在VxWorks系统下的运行信息生成动态蓝图,从而指导软件的重构。     

位置不确定移动对象的连续概率反Skyline查询

为了确保包括非功能属性在内的服务规约与服务实际运行行为之间的一致性,提出一种Web服务运行时行为验证方法。首先对UML 2.0序列图进行扩展,将QoS属性和功能属性的描述统一起来,以精确表达Web服务的需求规约。然后,提出利用确定有限自动机构造出扩展序列图(Extended Sequence Diagrams,ESD)的语义模型的方法。最后,给出验证准则,根据Web服务的交互消息和规约建模的结果来验证Web服务运行时行为与需求规约之间的一致性。基于上述研究,设计开发了Web服务运行时验证工具(Runtime Verification Tool for Web Services,RVT4WS),以支持对Web服务运行时行为的验证。     

软件可靠性评估中 UML 应用

在开放环境下,软件规模日趋扩大,结构更加多元化,传统的基于状态的软件可靠性评估方法,状态空间膨胀增加了计算复杂度,而且不能对多种典型的系统结构进行很好的描述。为此,对传统的方法进行了改进,用UML的用例图分解系统,序列图描述子系统,并都作为软件可靠性分析的输入,通过自底向上的方法评估软件的可靠性,符合当前大规模复杂结构的软件系统可靠性评估。     

面向安全属性的机器人运行时验证

为了保证机器人操作系统(Robot operating system,ROS)的安全性,提出一个运行时验证框架ROS-Monitor来监控系统。将所有的监控信息分为节点消息和节点行为,并实现从用户自定义场景模型自动生成相应监控器的工具。实验证明了该方法的有效性。     

基于程序运行形式化分析的软件故障监控技术

关键软件要求极高的可靠性和安全性,然而当前的技术途径尚不能完全消除软件故障——软件测试不能保证软件正确性,模型检查等形式化验证技术也存在着诸多局限。文章提出了基于监控程序运行途径来捕获软件故障和验证程序性质正确性,构建了基于程序运行形式化分析的软件故障监控（SFMRFA）模型,在监控逻辑表达、程序插桩、multi-agent设计等关键技术的基础上开发计算机辅助工具来监控、分析和引导程序执行,使软件运行当中可测、可控,避免软件失效。     

一种基于多维属性的CPS软件可信性评估方法

信息物理融合系统(CPS)是一种融合了物理过程和计算进程的新型系统,在信息物理融合系统中,存在多种软件且每个软件的运行环境是动态变化的。如何有效保证软件在动态环境下的正确性、安全性、可靠性等属性是值得关注的问题,而可信评估可为软件质量的控制和管理提供有力依据。提出了一种基于多维属性的CPS软件可信性评估方法。首先提出一种基于多维属性的可信指标系统,在此基础上提出一种具有时效性的可信属性评价方法,用以评价CPS软件的可信性;然后,设计可信性结果决策规则集,根据软件间的交互结构,计算出软件系统的可信性,并根据决策规则集评价软件系统可信性;最后通过一个实例进一步说明了所提方法的有效性。     

离散事件系统的混合分散监控

研究了混合信息下的分散监控综合问题.首先提出δ-可观察(hδ-可观察)可控闭语言是(状态部分可观察下)状态反馈综合解存在的充要条件,并由此得到n-联合可观察、可控闭的系统约束是保证混合分散监控器存在的充要条件,进而得到纯分散监控器(控制器)存在的充要条件为n-可观察(n-hδ-可观察)可控闭语言被满足.最后,又通过研究系统约束与混合约束的关系,提出混合分散监控器存在的充分条件是可观察、可控闭语言与可观察可控谓词被满足.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.