一种参照MAP标准实现的宽带计算机通信子网

遵循MAP协议的宽带网络是未来的自动化工厂实现计算机综合制造系统(CIMS)所不可缺少的,因而其协议、软件和硬件的研究和开发倍受重视。本文介绍一种参照MAP标准实现的宽带计算机通信子网,它主要由ISO/OSI参考模式的下三层,即物理层、链路层和网络层组成。该通信子网已在实验室进行了成功的数据传送实验。     

MAP及其发展动态

美国通用汽车公司制定的MAP计算机网络标准发展十分迅速,它特别适用于工厂自动化领域的计算机局部区域网络。本文综述了MAP标准的产生背景,介绍了MAP规范、应用形式、发展动态及其意义。     

协议工程行为模型的研究

近年,随着计算机网络和分布式系统的不断发展,各类新型通信技术和分布式应用已开始出现,其中主要包括高速光纤网、多介质通信、宽带综合业务数字网(B-ISDN)、智能网,以及综合语音、数据和图象服务等。它们已对计算机通信协议的设计和实现带来了很大影响。为了适应这种形势的发展,一门新兴的高科技学科—协议工程已应运而生。协议工程本质上是计算机硬件工程和软件工程的理论方法在通信协议设计和实现中的具体应用,但由于协议具有实时、互操作和同步性等特点,因而其复杂度又要比一般传统软件大得多。协议工程的主要研究目标是使协议软件的生产怎样更好地实现规范化、工程化和自动化。它所包含的基本内容     

MAP协议集及其在CIMS中的实现方法

MAP协议集是CIMS制造自动化分系统理想的网络体系结构.本文论述第一层基于IEEE 802.3协议的MAP功能的实现以及IEEE 802.3、IEEE 802.4协议的特点、CSMA/CD总线网的效率、响应时间,给出了基于IEEE 802.3 MAP功能实现的限定条件.     

工业控制网络协议MAP技术的研究与实现

计算机综合制造系统CIMS(Computer Integrated Manufacturing System)中最重要的子系统是计算机局部网络,MAP(Manufacturing Automation Protocol)则是CIMS系统中计算机局部控制网络的通信协议。本文着重研究MiniMAP网络技术,通过把目前技术比较成熟的产品(如ARCNET网络)和MiniMAP协议相结合,实现一种投资省、研制周期快的MiniMAP网络。     

无线mesh网络路由协议的研究

无线mesh网络是一种新型的无线宽带接人、多跳网络,它融合了无线局域网和移动Ad hoc网络的优点.根据无线mesh网络的结构特点,讨论和比较了无线mesh网络中各种路由协议的由来及其各自的特点,对现有的路由协议进行了分析和概括,指出了每种路由协议各自所具有的优缺点,最后讨论了无线mesh网络路由协议的一些应用以及未来的研究方向.     

局布网络 以太网与麦波网

计算机通迅网络,目前比较著名的是以太网Ethernet和麦波网MAP。这两个网络在解决其各自的问题上,均己达到了顶峰,而且两者将很和谐地存在、发展。目前,制造自动化协议(MAP)普遍地受到注意和社会认可。对于具体用户,以太网和麦波网二者那一个更适合用户?这就要看用户将网络用在什么任务上。大部分己在发展且支持以太网和麦波网的公司均在使两者共存的问题上,做出努力。所谓共存是指以太网和麦波网在什么状态下将会连结一在。当初,以太网(IEEE802.3)是被设计成用于办公室及实验室中,而麦波网(IEEE802.4)则用于工厂     

动态路由协议RIP的配置研究

路由协议是计算机通信中数据包发送和接收的规则,同时它还为数据包的交换提供路径.RIP(Routing Information Protocal)即路由信息协议,它属于动态路由协议,是一种内部网关协议,适用于小型同类网络,它应用较早,是典型的基于距离的矢量路由协议.因此,RIP协议的配置比较重要.     

探讨计算机网络通信协议

网络通信协议是计算机网络的一个重要组成部分,是不同网络之间通信、交流的公共语言.有了它,使用不同系统的计算机或网络之间才可以彼此识别,识别出不同的网络操作指令,建立信任关系.本文介绍了网络通信协议的概念、分类、组成及作用,并重点介绍了TCP/IP协议族.     

基于TCP/IP协议栈的网络家电家庭网关的设计

提出了一种基于TCP/IP协议栈来实现网络家电网关的方法.利用TCP/IP协议栈中的IP,TCP,DHCP,DDNS等协议来实现一个完整的具备各种功能的家庭网关.这种设计将可以使现有的家庭计算机网络中的网关,如宽带路由器等只需要做少量的改动,就可成为一个网络家电的网关,满足实现未来网络家电远程控制和集中控制的需求.     

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.