工业以太网在控制系统中的应用前景

简要介绍了以太网技术在工业控制系统中应用的优势和面临的问题，着重讨论了以太网的确定性和实时性问题，展示了工业以太网应用于控制系统的前景。     

PROFINET及其应用

1．PROFINET实时通讯技术是工业以太网进入现场级通讯的钥匙（概念介绍） PROFINET由PROFIBUS国际组织（PROFIBUS International）推出，是新一代基于工业以太网技术的工业自动化通讯标准。PROFINET解决方案囊括了诸如实时以太网、运动控制、分布式自动化、故障安全以及网络安全等当前自动化领域的热点话题，并且，完全兼容工业以太网和现有的现场总线（如PROFIBUS）技术。因此，PROFINET技术的出现，将为工业自动化领域提供一种全新的通讯解决方案，即整个工厂全部使用一个网络连接在一起。     

工业以太网实时通信技术及进展

改善实时性之后,以太网已经成功地进入工业自动化信息层、控制层。以太网应用到工业现场设备层,实时性仍然是最大障碍。文章结合以太网的通信机制,探讨了典型的工业以太网实时性技术特点,介绍了能够应用于现场设备的确定性工业以太网———Ethernet Powerlink的解决方案。     

可靠实时工业控制网络的优化设计

从网络通信时延的角度入手,分析了工业以太网的响应时间特点,指明了以太网实时性改进有优化方法.提出了一种可靠实时的的工业控制网络设计方案,并分别从网络主控制模块、通讯模块和显示操作模块进行实时性和可靠性的优化设计.文章详细介绍的具体的实现方案的预期达到的优化效果.     

论六种实时以太网的通信协议

在研究工业网络实时性要求的基础上，给出了工业以太网和实时以太网的定义，深入分析了6种主要实时以太网的通信协议。并概要论述了以太网运动控制、网络安全和以太网延伸至现场设备级等关键技术。同时，较全面地概述了我国ERA实时以太网技术及其标准。     

基于VC的执行机构以太网控制系统的设计

本文介绍了一种适用于过程控制领域的工业以太网监控系统的架构,通过主控计算机和工业以太网,可以方便的将所设计的各种网络化的电动执行机构按照我们的控制需要来连成网络,形成系统.通过自定义的通讯协议,保证了系统的实时性以及可靠性.通过通讯试验,证明了该控制系统是可行的.     

工业以太网中流量控制策略的研究

工业以太网技术应用于工业网络是网络控制技术的一大发展趋势。针对工业以太网络通信中存在的数据实时性、确定性等问题，提出了一种用于工业以太网的网络流量控制策略，同时利用数学模型和仿真测试验证了该算法，并将其成功应用在设计的网络流量控制器中。研究结果表明使用该流量控制策略后，工业以太网的网络数据拥塞现象得到了明显改善，可以满足工业现场应用以太网技术进行实时数据通信的要求。     

工业以太网认识的三大误区

介绍了以太网技术及其与现场总线相比的优势所在，提出并剖析了人们在以太网认识上的三大误区，即“以太网和TCP／IP等同”，“提高网络速度可以解决以太网应用于工业控制现场的实时性问题”，“引入以太网可以彻底实现系统的集成问题”。展望了工业以太网发展前景。     

Rabbit 2000在工业以太网中的应用研究

交换技术和全双工技术在以太网中的应用使得工业以太网的通信实时性和确定性大大提高，底层智能节点是基于Rabbit2000的嵌入式系统，它具有实时性好和可靠性高等优点，基于交换式以太网的嵌入式测控系统将两者进行了有机的结合。首先介绍了控制系统的结构，然后分析了通信系统的流程，最后用仿真结果证明了系统的可行性和有效性。     

一种面向控制应用的总线以太网改进协议

在底层工业控制网络中，以太网和TCP／IP协议的应用已经成为研究和发展热点．针对控制应用实时性和确定性要求，提出一种面向控制应用的总线以太网CSMA／CD-Master／Slave切换混合协议，并在其上构建了UDP／IP协议，分析和仿真结果表明．该协议在负载变化时确实能够提高通讯实时性和可靠性．其实现只需对现有协议软件进行部分改动．因而在计算机控制网络应用中具有一定实际价值．     

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.