多处理器系统的互连网络

本文是一篇面向研究的综合报告,系统地简介了目前存在的各种互连网络.其中,包括单级网孔连接网络、加减2~i网络、均匀洗牌交换网络和立方网络;多级阻塞的二进制n立方网络、Staran Flip网络、Omega网络、Delta网络、数据变换器、Gamma网络和榕树网络;多级非阻塞的Clos置换网络、可重新排列的Benes和Waksman置换网络和一到多的一般化连接网络.     

网络拥塞的原因分析及当前的预防措施

在网络中,传输的数据包大于网络信道的承载能力时,就会引起网络拥塞,在拥塞严重时可造成网络瘫痪。在硬件设备飞速发展的今天,造成网络拥塞的主要原因不再是硬件设备的性能满足不了用户的需求,而是某些人应用某种方法故意使网络拥塞来达到某种目的,而这些人的目的一般是恶意的,例如终止某种网络服务或报复性的网络破坏等。为了防止这些人使网络拥塞,甚至使网络瘫痪,需要制订一些网络策略来预防或排除网络拥塞。     

网络隐语的现状及其折射的网民心理

网络作为语言的一个新载体,催生了语言的新语体——网络隐语。本文从网络隐语的概念、网络隐语的特点、网络隐语的生成方式、常见网络隐语的分类以及网络隐语折射的网民心理等方面进行了研究,进而总结出常用的网络隐语。     

网络用语的魔力

从网络诞生之日起,网络用语就已存在。当网络成为流行文化的主流,网络用语则浓缩了网络流行文化,无数脍炙人口的网络用语在最短的时间内风靡街头巷尾,成为日常人们交流的口头禅,这就是网络用语的魔力。无论你喜不喜欢,玩不玩网络,它都在影响着我们的生活。     

车载传感器网络的研究进展

车载传感器网络是一种建立在车载自组织网络基础上的以数据为中心的新型移动传感器网络。与传统传感器网络不同的是,车载传感器网络中的节点是高速移动的,从而导致网络间歇连通、拓扑结构变化频繁,网络中数据的传输只能依靠节点间机会性的传递,严重影响了这种以数据为中心的网络中的数据传输的性能。对目前车载传感器网络的研究现状进行了分析讨论,同时结合延迟容忍网络和机会网络思想,给出了车载传感器网络的研究方向。     

基于虚拟现实技术的网络学习的应用研究

随着网络技术的发展,基于网络的网络学习已成为人们关注的热点。该文就如何通过虚拟技术,增加网络学习的实用性,从而适应基于网络的网络学习的需要,提高教学质量和学者学习的兴趣。     

网络数据库的数据安全策略

随着我国网络信息技术的迅猛发展,网络数据库也随之得到了推广应用。如今,网络信息已经深入到我们工作、学习和生活的各个方面,网络信息的安全性也显得越来越重要。网络数据库的数据安全是决定网络信息安全的关键。本文就网络数据库进行了简单阐述,对网络数据库的主要威胁进行了分析,在此基础上提出了网络数据库数据的数据安全策略。     

改进TCP拥塞控制算法的仿真及应用研究

研究网络拥塞优化控制问题.由于网络承载量猛增,产生堵塞,延迟增加,使网络效率降低.传统网络的TCP拥塞控制算法不能区分网络拥塞和网络随机错误丢包,导致网络带宽利用率低,网络拥塞严重,甚至导致网络崩溃.为了降低网络拥塞的概率,提出了一种改进的TCP拥塞控制算法.改进的网络拥塞控制算法首先通过对网络状态进行预测,能够有效区分网络拥塞和网络随机错误丢包,同时对TCP网络拥塞控制算法的拥塞避免、快速重传和快速恢复机制进行改进,改善网络性能.最后采用NS2仿真器对算法进行仿真,实验结果表明,提高了网络平均吞吐量,带宽利用率更高,很好的避免了网络拥塞.     

基于复杂网络的学生交流网络模型

基于QQ网络实证数据分析,研究了Internet网络中的QQ网络模型。在调查得到的QQ网络数据库基础上,通过比较网络度分布图形与网络特征参数,发现QQ网络与现有的BA模型差别较大。通过分析QQ网络参数特性,提出了一个新的网络演化模型。统计分析结果表明,新的网络参数与QQ网络参数基本一致。所提出的新模型为QQ网络研究提供了有力的理论支持。     

基于ns的局域网上网络仿真环境的构建方法

1.引言网络模拟(Network Simulation)是网络协议开发人员在设计和评测网络协议时使用的重要方法。网络模拟提供一个可重复、易控制的试验环境,并且建立和运行的费用低。网络模拟将协议实现抽象成模型(即虚拟的协议实现),并将其放在虚拟的网络环境下观察。网络仿真(Network Emulation)是在网络模拟的基础上增加和真实网络的接口,实现真实网络和虚拟网络的交互。网络仿真可以看作网络模拟器和真实协议实现的混合体。仿真器内部简化的协议实现提供了接收、处理和产生真实网络报文的能力;转化装置介于真实网络和仿真器之间、它能够将真实网络报文转换为模拟报文.也可以将模拟报文转换为真实网络报文,从而使得仿真器内部的协议     

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.