构件化移动agent创建方法研究

分析了Client/Server中C/S结构与B/S结构,指出两种结构都不适用于移动agent。提出了一种构件化移动agent创建方法。采用程序变换技术,将移动agent体系结构分为本体体系结构和虚拟体系结构。本体体系结构表达移动agent实现特性,虚拟体系结构表达移动agent接口特性。最后,文章给出了一个移动agent体系结构,表明该文提出的创建方法在实践上确实可行、有效,较好地解决了上述结构的不足。     

一种基于元数据的采样模拟技术优化

分析了目前主流采样模拟技术中定长样本的不足,提出了一种基于编译器元数据的采样模拟技术(BigLoopSP).首先利用编译器收集各种可能的周期行为的边界信息作为元数据.然后为了处理程序中大量存在的动态行为,基于编译器产生的元数据结合程序的动态行为进行周期行为的划分和采样点的选取.以此方案划分的变长候选样本能够在保证样本质量的前提下有效地减少所需特征样本的总数.因此比较于定长采样技术SimPoint,BigLoopSP在提高精确性的同时,进一步降低了模拟所需的时间(相对于SimPoint的平均加速比为2.63).     

可重定向的周期精确模拟器生成环境研究

针对嵌入式系统设计对模拟器生成环境可重定向性的要求,以及当今大多数生成环境多为功能级,而不支持周期级模拟的现状,本文提出了一个可重定向的周期精确模拟器的自动生成环境.通过体系结构描述语言xpADL对目标体系结构的组成和周期级行为进行描述,利用生成器和构件库完成了模拟器的生成.其中,xpADL的描述构架、生成器的分析机制和构件库中控制模拟框架的应用,使得与现有的生成环境相比,此环境在指令的周期级行为、流水线组织和流水化部件的模拟能力等方面均具有优势.实验部分完成了PISA和StrongARM两种体系结构的周期级模拟,并进行了针对加解密应用的流水线结构设计空间搜索的研究,证明了该环境的可重定向性和有效性.     

基于系统调用的神经网络异常检测技术

给出了一种基于程序行为的神经网络异常检测技术,通过使用ELMAN网络,利用了程序执行时的系统调用的周期重复特性,使该系统具有检测新型入侵攻击和具有较低虚警率的特点。     

基于程序周期行为的快速模拟方法

提出了一种基于程序周期行为的快速模拟方法,通过对基本块执行次数和基本块跳转关系进行统计采样和分类,选择有代表性的程序片段来执行,能够在保证模拟精度的同时极大地缩短模拟时间。实验结果表明,在模拟了龙芯2号微体系结构的sim-godson模拟器上,采用这种方法SPEC2000测试程序可以在1h内运行完,误差率不超过5%。     

面向存储层次设计优化的GPU程序性能分析

图形处理器凭借着比传统CPU更高的峰值性能和能效,以及日渐成熟的软件环境,逐渐成为构建异构并行系统的最流行的加速器之一。虽然GPU依靠轻量级线程的灵活切换来隐藏访存延迟,但其超高的并发度仍然给存储系统带来了很大压力,其性能的有效发挥受访存效率的强烈影响。因此GPU程序的访存行为分析及优化一直是GPU相关领域的研究热点,但很少有工作从体系结构的角度分析存储层次的设计对性能的影响。为了更好地指导GPU存储层次的设计和访存优化,从实验的角度详细地分析了GPU各存储层次对程序性能的影响,并总结出若干指导性的优化策略,为未来类似体系结构的存储层次设计和程序优化提供建议。     

影响分布式控制系统性能的若干因素

分布式控制系统(DCS)是工业控制应用技术的热点和主流.本文简要地阐述了系统体系结构的架构、时间延迟、控制网络和通讯调度等这些因素对控制系统整体性能的影响以及相关研究现状.并指出系统的、恰当的方法分析DCS的行为特性,允许系统集成人员能够快速评价多种不同方案并从中选择最佳方案而无需大量的仿真,在此基础上,对系统体系结构进行优化.这是DCS研究需要进一步深入的课题.     

基于JSP的WEB数据库应用系统设计

本文分析了目前流行的网站建设技术，采用三层体系结构，注重安全与效率，应用JSP的特性快速开发WEB程序。在数据库设计方面针对网站做了一些适应性的设计。     

IA-64二进制翻译中优化代码消除技术

IA-64架构为获得高性能支持许多先进体系结构的特性,例如显式指令级并行,指令判定执行,以及投机装入等,这些特性对编译器是可见的,但是为了充分利用这些体系结构的特性,编译器优化往往将程序的代码进行深度重构,使得从优化后的可执行代码中很难恢复源程序逻辑。本文提出了在IA-64二进制翻译中应用优化代码消除技术,提高翻译效率和生成目标机代码的质量。     

基于语义层软件理解的形式化格局识别技术

目前国内外学者在软件理解的研究上多注重于程序的词法层和语法层技术的探索,相应的有程序切片、程序类跟随踪、程序依赖性分析、反汇编与反编译等。但对程序的语义层理解方法进行研究的甚少。该文正是基于上述分析研究了一种软件理解新认识水平——形式化格局识别技术,以行为层状结构的变换来表述程序的语义,进而采用近人类的思维方式来理解并抽取软件的设计决策与体系结构。     

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.