基于嵌入式模块实现RS-485与工业以太网的通信

由于以太网技术在确定性，速度和信息优先级等方面有了突破性进展，因而把以太网技术从商业应用领域引入到现场控制领域将是工业控制系统发展的最佳选择。本基于一种全新的嵌入式以太网控制模块，提供一种将原先使用RS－485通信的传感器等自动化元件便捷接入工业以太网的解决方案，并列举了应用实例。     

引入以太网技术是现场总线技术发展的一个必然趋势

工业控制领域需要一种高速廉价的网络。在过去几年,以太网标准有了许多进步,特别是确定性、速度和信息优先级等方面。交换技术的快速发展大大消除了以太网应用于控制领域的障碍。目前许多组织和公司致力于将以太网与现场总路线实现无缝连接,发展的趋势是以太网越来越向底层延伸。还介绍了现场总线基金会的HSE和PROFIBUS联合会的PROFIBUS以太网发展计划。     

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。     

改进的WRR策略在交换式工业以太网中的最大时延计算

为满足不同类型的数据在交换式工业以太网中传输的不同要求,在交换机中引入具有优先级队列的加权轮循(Weighted Round Ring,WRR)策略,应用网络演算理论推导不同类型的数据在该策略下的等待时延上界,得出计算公式,并与绝对优先级调度算法进行比较,展现该策略在工业以太网中应用的优越性.     

以太网上的多媒体传输

为了在以太网上有效地传输多媒体信息，本文提出了一种位于传输层的基于动态优先级调度的令牌传递策略，对发向以太网的数据包进行控制，避免碰撞的发生，保证数据的定时发送。     

基于QOS区分服务的以太NCS的MAC协议设计及仿真

结舍QoS区分服务的概念,在CSMA／CD基础上提出了一种新的以太网MAC协议：DS-CSMMCD。并引入网络建模工具Opnet Modeler对该协议进行建模分析,得到了一些实用的网络配置参数,模拟结果达到了预期效果,能在时限要求内有效的区分开不同优先级信息的服务延迟。该协议兼容CSMMCD,可以扩展到上层网络,为以太网在工业控制领域底层的应用提供了一些有益的思路。     

基于网络演算计算交换式工业以太网中的最大时延

为保证周期性实时数据在交换式工业以太网中的服务质量,在交换机中引入非抢占式的优先级调度方法,并在源节点对进入网络的非周期数据流进行漏桶管制;基于网络演算理论推导了交换机对不同类型数据的服务曲线;针对一个树型拓扑的交换式工业以太网模型,利用所推导出的结论计算了实时数据的最大网络时延.     

交换式工业以太网的现状和研究

首先介绍了交换式以太网为支持实时工业通信所提供的新特性,探讨了交换式以太网应用于工厂底层时需要解决的关键技术:如优先级服务、多播的解决方法和底层智能仪表的开发等.然后对交换式工业以太网的研究进行了综述.     

新型实时工业以太网MAC协议的设计与实现

论文介绍了一种基于载波长度的信令传播机制,根据信元的包长建立优先级,新型的实时以太网介质访问控制协议通过引入信道阻塞模式,在标准以太网信道上为硬实时信息提供具有上限的传输时延保证。在OPNET仿真环境下,详细描述了用离散时间驱动的有限状态机实现协议的建模方法,并通过仿真验证了协议的正确性和有效性。     

交换式以太网数据采集和分析软件

交换式以太网数据采集系统以交换式,高速,宽速皮太网为基础,ＣＡＭＡＣ系统直接与网络接口,避免了为单个计算机系统重写ＣＡＭＡＣ驱动程序,保证了网络上ＣＡＭＡＣ系统和主机之间较高的数据传输率。利用其中的数据采集和分析软件,用户不必写任何代码就可以建立一个完整的数据采集通道,获取并处理数据。     

An Analysis of the Criteria for Evaluating Adequate Theories of Computation

This paper deals with the question: What are the criteria that an adequate theory of computation has to meet? (1) Smith’s answer: it has to meet the empirical criterion (i.e. doing justice to computational practice), the conceptual criterion (i.e. explaining all the underlying concepts) and the cognitive criterion (i.e. providing solid grounds for computationalism). (2) Piccinini’s answer: it has to meet the objectivity criterion (i.e. identifying computation as a matter of fact), the explanation criterion (i.e. explaining the computer’s behaviour), the right things compute criterion, the miscomputation criterion (i.e. accounting for malfunctions), the taxonomy criterion (i.e. distinguishing between different classes of computers) and the empirical criterion. (3) Von Neumann’s answer: it has to meet the precision and reliability of computers criterion, the single error criterion (i.e. addressing the impacts of errors) and the distinction between analogue and digital computers criterion. (4) “Everything” computes answer: it has to meet the implementation theory criterion by properly explaining the notion of implementation.     

一种面向查询的多文档摘要方法

面向查询的多文档摘要技术有两个难点 第一,为了保证摘要与查询密切相关,容易造成摘要内容重复,不够全面;第二,原始查询难以完整描述查询意图,需进行查询扩展,而现有查询扩展方法多依赖于外部语义资源。针对以上问题,该文提出一种面向查询的多文档摘要方法,利用主题分析技术识别出当前主题下的子主题,综合考虑句子所在的子主题与查询的相关度以及子主题的重要度两方面因素来选择摘要句,并根据词语在子主题之间的共现信息,在不使用任何外部知识的情况下,进行查询扩展。在DUC2006评测语料上的实验结果表明,与Baseline系统相比,该系统取得了更高的ROUGE评价值,基于子主题的查询扩展方法则进一步提高了摘要的质量。     

Gain-scheduled H ∞ filtering of parameter-varying discrete-time systems via parameter-dependent Lyapunov functions

This paper is concerned with the problem of gain-scheduled H _∞ filter design for a class of parameter-varying discrete-time systems. A new LMI-based design approach is proposed by using parameter-dependent Lyapunov functions. Recommended by Editorial Board member Huanshui Zhang under the direction of Editor Jae Weon Choi. This work was supported in part by the National Natural Science Foundation of P. R. China under Grants 60874058, by 973 program No 2009CB320600, but also the National Natural Science Foundation of Province of Zhejiang under Grants Y107056, and in part by a Research Grant from the Australian Research Council. Shaosheng Zhou received the B.S. degree in Applied Mathematics and the M.Sc. and Ph.D. degrees in Electrical Engineering, in January 1992, July 1996 and October 2001, from Qufu Normal University and Southeast University. His research interests include nonlinear control and stochastic systems. Baoyong Zhang received the B.S. and M.Sc. degrees in Applied Mathematics, in July 2003 and July 2006, all from Qufu Normal University. His research interests include and nonlinear systems, robust control and filtering. Wei Xing Zheng received the B.Sc. degree in Applied Mathematics and the M.Sc. and Ph.D. degrees in Electrical Engineering, in January 1982, July 1984 and February 1989, respectively, all from the Southeast University, Nanjing, China. His research interests include signal processing and system identification.     

A method of defuzzification based on the approach of areas' ratio

The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.     

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.     

Audio recording of rock/metal music using personal computers

Personal computers and their relevant technologies have been widely used by artists and musicians to create and record their own music and electroacoustic compositions. ＂Laptoppers＂ are famous for using their laptops for their dance/electronic beats and music. A genre that has not relied on the use of PCs for the production of its music is rock/heavy metal, since bands of these genres usually book recording studio time where professionals take on the task of the production using expensive equipment. This study shows that in today＇s day and age, and with the software and hardware currently available, it is possible for rock/metal artists to use their PC to record and produce their own CD successfully and at an extremely competitive cost. The effort＇s of a rock band that does just this is followed from the beginning and the results of their CD production and song successes is presented. The article also serves as a ＂HowTo＂ guide that bands on a low budget can follow to make good quality demo CDs and enter the music business industry.     

类别不平衡的多任务人脸属性识别

属性的识别对物体的识别起到了比较重要的作用,例如人脸验证和场景识别。提高属性的识别率对后面基于属性特征的应用的正确率有很大的影响。近些年来,有些工作也开始关注于属性的学习,而很多的工作都是基于属性之间独立的假设,但在实际中很多的属性都是强相关的,例如没有胡子和女性,光头和头发的颜色;很多的工作忽略了类别之间的不平衡性,例如光头的样本比例可能只占样本的很小一部分。基于这2个观察,本文提出一种基于多任务的类别不平衡的人脸属性识别网络架构,该网络结构是由Densenet修改而来。该方法比以往的方法效果要好,一定程度上缓解了不平衡问题,且参数少,计算效率更高,在公开人脸属性数据集CelebA和LFWA上的实验验证了该方法的有效性。     

Characterization and failure analysis of MEMS: high resolution optical investigation of small out-of-plane movements and fast vibrations

A high resolution optical tool is required to investigate the mechanical behavior and failure modes of micro-electromechanical systems (MEMS). We report on the possibilities of a newly developed optical characterization tool for MEMS devices. Both slow movements and fast mechanical vibrations up to 15 MHz can be monitored. The instrument can perform an imaging operation for a complete image at once by employing laser TV holography, which is a large advantage over scanning laser Doppler vibrometers. For vibration measurements, this new, interference based instrument uses a beat frequency between object excitation and reference beam excitation. A normal CCD camera is used to obtain 3D images and movies of periodic mechanical motions of MEMS devices. Excitation can be by means of a PZT, or by using electronic excitation. We show that the instrument is a very useful tool for the characterization and failure analysis of MEMS devices.The whole MEMS team at IMEC and their coworkers in projects are thanked for providing many of the samples shown in this paper. In particular, we would like to thank the following people. Melexis is thanked for providing the membrane sample of Fig. 4–6 and 14. Figs. 7–9 were measured in the frame of the MISTRA project (IWT contract 000167). Theo Rijks (Philips Natlab) provided the sample of Figs. 10 and 11. Chris Muhlstein sent the sample of Fig. 12 to us. Hans de Vries (Philips Centre for Industrial Technology/EP&A) is thanked for providing the sample of Fig. 13. The switch of Fig. 15 was made in the MIRS project (5012352345). Laurent Francis (IMEC) is thanked for providing the sample of Fig. 16. Sjoerd van de Geijn of Océ-Technologies B.V. provided the sample of Fig. 17.     

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.     

Impact of cognitive theory on the practice of courseware authoring

Abstract The cognitive revolution has yielded unprecedented progress in our understanding of higher cognitive processes such as remembering and learning. It is natural to expect this scientific breakthrough to inform and guide the design of instruction in general and computer-based instruction in particular. In this paper I survey the different ways in which recent advances in cognitive theory might influence the design of computer-based instruction and spell out their implications for the design of authoring tools and tutoring system shells. The discussion will be divided into four main sections. The first two sections deal with the design and the delivery of instruction. The third section analyzes the consequences for authoring systems. In the last section I propose a different way of thinking about this topic.