基于组件的分布式软件的动态配置和容错

论文提出一种结构化新方法,它能通过动态配置支持基于组件的分布式软件的容错。采用面向图形的编程模型,基于组件的分布式软件的软件体系结构可用一个逻辑图来表示,该逻辑图可以精化为一个明确的对象并分布到网络中,软件的动态配置通过执行定义在图上的一系列操作来实现,发生错误时通过动态重配置软件来支持容错。论文描述了该方法的基本模型、系统结构及其在CORBA上的实现原型。     

分布式软件体系结构中组件依赖的描述

分布式软件的动态配置及软件体系结构中的一个重要问题是对组件依赖的理解和描述。该文采用的方法提供了精确描述组件交互的基础,展示了分布式系统组件间的拓扑关系,进而描述了软件体系结构。该方法还对组件测试提供了有力支持,它的突出优点是用一种方法来描述体系结构并支持软件测试。     

软件体系结构建模研究

提出了软件体系结构工程的概念，建立了软件体系结构的生命周期模型并对软件体系结构进行了分类和建模，介绍了几种典型的软件体系结构语言，提出了一个基于时序逻辑的形式化体系结构语言－ＸＹＺ／ＳＡＥ．该语言可作为系列化时序逻辑语言族ＸＹＺ／Ｅ的子语言，支持对软件体系结构可的构件，连接件和配置的描述，并可在统一的框架下描述软件体系的结构静态行为和动态行为。     

ABC:基于体系结构、面向构件的软件开发方法

基于构件的软件复用和开发被认为是提高软件开发效率和质量的有效途径,并在分布式系统中得到了广泛的应用.但是,目前的软件构件技术主要还是着眼于构件实现模型和运行时互操作,缺乏一套系统的方法以指导整个开发过程.近年来,以构件为基本单元的软件体系结构研究取得了较大的发展.它通过对软件系统整体结构和特性的描述,为面向构件的软件开发提供了一个自顶向下的途径.介绍了一种以软件体系结构为指导,面向构件的软件开发方法,试图为基于构件的软件复用提供一种有效的解决方案.这种方法主要是将软件体系结构引入到软件开发的各个阶段,作为系统开发的蓝图,利用工具支持的自动转换机制缩小从高层设计到实现的距离,而后在构件平台的运行支持下实现自动的系统组装生成.     

一种支持软件体系结构重用的反射机制RMRSA

软件实现阶段的重用技术,特别是组件重用技术已经取得了巨大的进展。然而,对于软件开发早期阶段的软件资源的重用却进展缓慢。软件体系结构在软件重用中有着特殊的意义。反射机制在代码重用方面取得了成功,但还没有用于软件体系结构及其组成元素的重用。提出了一种支持软件体系结构设计时重用的反射机制,概述了基于反射机制的软件体系结构重用方法。详细说明了反射机制RMRSA的元级体系结构模型和基级体系结构模型,描述了元级软件体系结构和基级软件体系结构之间进行交互和互操作的协议PMB,以及反射机制RMRSA支持软件体系结构重用的过程。利用所提出的基于反射机制的重用方法,设计人员在软件设计阶段,通过重用体系结构及其组成元素来高效地完成软件计任务。     

Z语言与软件体系结构风格的形式化

软件体系结构风格是软件设计人员在长期开发某种类型软件经验的基础上总结出来的适合于构建某一类软件的模型,也称为构建模式.形式化则是一种基于数学的严谨的描述方式和方法.形式化不仅能够清晰地描述软件体系结构风格,并且为软件体系结构的设计提供了一种易于交流和理解的途径,因此形式化是现在软件体系结构研究的主要课题之一.文中通过Z语言描述管道一过滤器这一软件体系结构风格静态性质和动态行为来说明如何运用Z语言形式化的描述软件体系结构风格,从中可以看出Z语言的严谨、清晰、简洁.     

基于Multi-Agent的动态配置软件体系结构研究

本文介绍了一种基于多代理的动态配置软件体系结构。对于采用基于构件的软件开发方法开发的软件系统,利用这种动态配置中间件能够根据配置请求在系统运行期间调整构件连接关系和完成构件升级,实现系统的动态配置,并且保证系统始终处于正常工作状态。在动态配置框架中,作为软件组成元素的每个构件被封装成具有智能性和机动性的Agent,能够自主地进行构件升级和结构调整。     

一种面向图的分布式软件动态配置和容错方法

提出一种新的方法，通过动态配置对基于组件的分布式软件的容错提供支持。此方法采用面向图的GOP编程模型，将整个分布式软件的体系结构用一张逻辑图来描述，系统的动态配置可以通过执行图上预定义的一组操作来完成。检测到故障或异常的时候实施这种动态配置能够支持系统的容错。文中描述了此方法的基本模型、系统结构和基于CORBA的原型实现。     

基于UML的多agent系统软件体系结构建模研究

针对面向agent软件开发方法普遍缺乏对多agent系统软件体系结构的描述的问题,基于UML 2.0规定的两种扩充方式,在UML元模型的基础上增加了描述多agent系统和软件体系结构两个方面特征的建模元素,并用八个视图对多agent系统的软件体系结构进行描述,最后通过实例说明了该方法适用于多agent系统软件体系结构的构造.     

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.     

An Analysis of the Criteria for Evaluating Adequate Theories of Computation

This paper deals with the question: What are the criteria that an adequate theory of computation has to meet? (1) Smith’s answer: it has to meet the empirical criterion (i.e. doing justice to computational practice), the conceptual criterion (i.e. explaining all the underlying concepts) and the cognitive criterion (i.e. providing solid grounds for computationalism). (2) Piccinini’s answer: it has to meet the objectivity criterion (i.e. identifying computation as a matter of fact), the explanation criterion (i.e. explaining the computer’s behaviour), the right things compute criterion, the miscomputation criterion (i.e. accounting for malfunctions), the taxonomy criterion (i.e. distinguishing between different classes of computers) and the empirical criterion. (3) Von Neumann’s answer: it has to meet the precision and reliability of computers criterion, the single error criterion (i.e. addressing the impacts of errors) and the distinction between analogue and digital computers criterion. (4) “Everything” computes answer: it has to meet the implementation theory criterion by properly explaining the notion of implementation.     

一种面向查询的多文档摘要方法

面向查询的多文档摘要技术有两个难点 第一,为了保证摘要与查询密切相关,容易造成摘要内容重复,不够全面;第二,原始查询难以完整描述查询意图,需进行查询扩展,而现有查询扩展方法多依赖于外部语义资源。针对以上问题,该文提出一种面向查询的多文档摘要方法,利用主题分析技术识别出当前主题下的子主题,综合考虑句子所在的子主题与查询的相关度以及子主题的重要度两方面因素来选择摘要句,并根据词语在子主题之间的共现信息,在不使用任何外部知识的情况下,进行查询扩展。在DUC2006评测语料上的实验结果表明,与Baseline系统相比,该系统取得了更高的ROUGE评价值,基于子主题的查询扩展方法则进一步提高了摘要的质量。     

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.     

A method of defuzzification based on the approach of areas' ratio

The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.     

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.     

Impact of cognitive theory on the practice of courseware authoring

Abstract The cognitive revolution has yielded unprecedented progress in our understanding of higher cognitive processes such as remembering and learning. It is natural to expect this scientific breakthrough to inform and guide the design of instruction in general and computer-based instruction in particular. In this paper I survey the different ways in which recent advances in cognitive theory might influence the design of computer-based instruction and spell out their implications for the design of authoring tools and tutoring system shells. The discussion will be divided into four main sections. The first two sections deal with the design and the delivery of instruction. The third section analyzes the consequences for authoring systems. In the last section I propose a different way of thinking about this topic.     

CONFLUENT POSSIBILITY DISTRIBUTIONS AND THEIR REPRESENTATIONS

Possibilistic distributions admit both measures of uncertainty and (metric) distances defining their information closeness. For general pairs of distributions these measures and metrics were first introduced in the form of integral expressions. Particularly important are pairs of distributions p and q which have consonant ordering—for any two events x and y in the domain of discourse p(x)⪋ p(y) if and only if q(x) ⪋ q(y). We call such distributions confluent and study their information distances.

This paper presents discrete sum form of uncertainty measures of arbitrary distributions, and uses it to obtain similar representations of metrics on the space of confluent distributions. Using these representations, a number of properties like additivity. monotonicity and a form of distributivity are proven. Finally, a branching property is introduced, which will serve (in a separate paper) to characterize axiomatically possibilistic information distances.     

CCD camera modeling and simulation

In this paper we propose a modeling of an acquisition line made up of a CCD camera, a lens and a frame grabber card. The purpose of this modeling is to simulate the acquisition process in order to obtain images of virtual objects. The response time has to be short enough to permit interactive simulation. All the stages are modelised: in the first phase, we present a geometric model which supplies a point to point transformation that provides, for a space point in the camera field, the corresponding point on the plane of the CCD sensor. The second phase consists of modeling the discrete space which implies passing from the continous known object view to a discrete image, in accordance with the different orgin of the contrast loss. In the third phase, the video signal is reconstituted in order to be sampled by the frame grabber card. The practical results are close to reality when compared to image processing. This tool makes it possible to obtain a short computation time simulation of a vision sensor. This enables interactivity either with the user or with software for the design/simulation of an industrial workshop equipped with a vision system. It makes testing possible and validates the choice of sensor placement and image processing and analysis. Thanks to this simulation tool, we can control perfectly the position of the object image placed under the camera and in this way, we can characterise the performance of subpixel accuracy determining methods for object positioning.     

Gain-scheduled H ∞ filtering of parameter-varying discrete-time systems via parameter-dependent Lyapunov functions

This paper is concerned with the problem of gain-scheduled H _∞ filter design for a class of parameter-varying discrete-time systems. A new LMI-based design approach is proposed by using parameter-dependent Lyapunov functions. Recommended by Editorial Board member Huanshui Zhang under the direction of Editor Jae Weon Choi. This work was supported in part by the National Natural Science Foundation of P. R. China under Grants 60874058, by 973 program No 2009CB320600, but also the National Natural Science Foundation of Province of Zhejiang under Grants Y107056, and in part by a Research Grant from the Australian Research Council. Shaosheng Zhou received the B.S. degree in Applied Mathematics and the M.Sc. and Ph.D. degrees in Electrical Engineering, in January 1992, July 1996 and October 2001, from Qufu Normal University and Southeast University. His research interests include nonlinear control and stochastic systems. Baoyong Zhang received the B.S. and M.Sc. degrees in Applied Mathematics, in July 2003 and July 2006, all from Qufu Normal University. His research interests include and nonlinear systems, robust control and filtering. Wei Xing Zheng received the B.Sc. degree in Applied Mathematics and the M.Sc. and Ph.D. degrees in Electrical Engineering, in January 1982, July 1984 and February 1989, respectively, all from the Southeast University, Nanjing, China. His research interests include signal processing and system identification.