路由器与交换机的主要区别

路由器与交换机的主要区别体现在以下几个方面：（1）工作层次不同 最初的的交换机是工作在OSICRM开放体系结构的数据链路层,也就是第二层,而路由器一开始就设计工作在OSI模型的网络层。由于交换机工作在OSI的第二层（数据链路层）,所以它的工作原理比较简单,而路由器工作在OSI的第三层（网络层）,可以得到更多的协议信息,路由器可以做出更加智能的转发决策。     

电力载波多联机空调通信系统的设计与开发

为了降低多联机空调系统的成本、简化安装工程,采用电力线载波通信技术构建了多联机空调的通信系统。首先根据系统控制的通信需求提出了基于窄带电力线通信技术的解决方案;然后主要从信道接入控制和组网控制两方面设计了包括物理层、介质访问控制（MAC）层、网络层和应用层的四层通信协议集,提出了基于载波侦听多路访问/冲突避让（CSMA/CA）设计思想的三种信道接入算法以及星型网络拓扑的组网算法;最后对11节点多联机空调系统进行了组网测试、正常通信测试和抗干扰测试。测试结果表明所提算法及方案能够满足多联机空调系统的实时控制要求,并具有较强的抗干扰能力;另外,所设计的通信协议具有开放性,可以根据需求进行修改,应用于智能家居等短距离无中继的实时控制领域。     

校园网信息系统安全防御体系的构建

在校园网应用过程中,人们往往侧重于网络环境安全,而忽视了信息系统层面的安全防范。针对校园网信息系统的特点,阐述了网络环境安全（网络层）、操作系统安全（服务器层）、信息系统软件安全（数据库应用程序层）等安全防范措施,构建了一套应用系统多层次安全防御体系。     

多速率移动自组网中交叉层优化的性能分析

由于严格分层的协议无法很好地适应移动自组织网络（Mobile Ad hoe Network,MANET）的动态变化,交叉层设计与优化近年来成为MANET的一个研究热点。针对802．11b标准支持的多速率通信,分别在网络层和MAC层实现了两种多速率控制方案,并通过仿真实验详细分析了这两种速率控制方案的性能。实验结果表明,在网络层引入物理层提供的多速率信息作为路由选取标准,可有效提高网络吞吐率,降低端到端延迟;同时,在MAC层使用高速率转发中继,对网络层路由进行局部优化,可以进一步改善对拓扑动态变化的适应性。     

煤矿监控类系统远程故障分析平台

针对煤矿监控类系统故障处理时效性低、现场维护工作量大、运维成本高等问题,在对故障信息进行统一规范的基础上,设计了一种煤矿监控类系统远程故障分析平台。该平台分为设备层、网络层、系统层和运维层。设备层内置具备故障自诊断能力的故障探针,检测到故障后将关联信息缓存,并上传至网络层。网络层收到设备层传来的故障信息后,先对设备层故障信息进行缓存,再连同网络层产生的故障信息一起打包上传至系统层。系统层部署的故障信息采集软件可通过内存接口、数据库或文本文件等方式从监控类系统上位机软件中获得故障信息,同时支持网络层设备故障信息直接采集,将故障信息缓存后传输至运维层。运维层将接收的故障信息存入故障信息中心库进行分析和推送。该平台可为煤矿监控类系统故障分析提供重要的数据支撑,为煤矿监控类系统运维服务提供有效的技术保障。     

基于LAMP架构的WEB服务安全优化方案

本文通过对LAMP系统层的配置优化到网络层的开发加固再到应用层的检测完善,为打造一个相对完善的SLAMP（Security-LAMP）WEB服务平台提供了一整套优化策略。     

基于多传感器的室内环境监控系统设计

为满足室内环境监控的新需求,设计并实现了一种基于多传感器的室内环境远程监控系统。系统采用物联网三层架构体系包括感知层、网络层和应用层,感知层主要实现室内环境信息监控、室内舒适性判断及有害气体预警功能;网络层负责传递数据信息;应用层负责数据发布,供用户远程实时获取室内环境信息。实验结果表明,该系统能远程实时监控室内环境,具有低功耗、操作简单、成本较低等优点。     

多方位网络拓扑发现的通用算法与技术实现

网络拓扑发现的算法和实现技术是衡量网络管理系统性能的一个重要方面。通过开发网络管理系统网络拓扑发现服务模块过程中获得的理论和实践经验,提炼了物理拓扑发现（网络层和子网层发现）,逻辑结构发现（虚拟局域网成员发现）和应用发现（服务扫描）中使用的核心算法,并进行了实际开发中的实践经验总结;同时阐述了将网络拓扑发现服务经封装作为MBean组件集成到基于JMX架构的整体系统中的技术和实现。     

中小企业局域网安全设计方案

文章分析了中小企业局域网特点,指出了面临的网络安全隐患,提出了基于MPDRR（安全管理、安全防护、安全检测、安全响应、安全恢复）网络安全模型的提供四层（应用层、系统层、网络层、物理层）网络纵深防御的安全解决方案和网络安全部署方案.     

单片机系统数据远程传输协议设计与实现

单片机系统在远程传输时,因其可靠性以及稳定性的要求,在实际的应用的基础上一种分层设计的传输协议被提了出来。协议分为接入层、网络层以及应用层。接入层解决了因通信方式不同而存在的问题,网络层解决了多种结构数据在不同网络结构中传输的问题,数据对象因组成方式的不同而对数据的传输效率有所影响。本文作者通过MODEM以及公用电话的远程传输为例,进行简单的探讨。和公用电话网实现远程通信的系统方案,     

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     

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.     

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。