英语专业文献阅读.ppt

059844 Developing linear error models for analog devices,Techniques are presented for developing linear error models for analog and mixed-signal devices. A simulation program developed to understand the modeling process is described, and results of simulation are presented. Methods for optimizing the size of empirical error models based on simulated error analyses are included.,Once established, the models can be used in a comprehensive approach for optimizing the testing of subject devices. Models are developed using data from a group of 13-bit A/D converters and composed with the simulation results.,开发模拟装置的线性误差模型。给出了开发模拟和混合信号装置线性误差模型的技术。描述了用于理解建模过程的仿真程序，给出了仿真结果。文中包括了基于仿真误差分析的经验误差模型规模的优化方法。一经建立，该模型便可在优化实验装置的测试中得到全面应用。模型的开发使用了从一组13位转换器上获得的数据和仿真结果。,Natl Inst,National Institute,Trans,transaction trAn5zAkF(E)n n.办理, 处理, 会报, 学报, 交易, 事务, 处理事务,034807 Software assembly workbench:how to construct software like hardware,This paper describes an approach for assembling software by combining reusable building blocks, much in the way hardware is being designed. The approach uses a Software Assembly Workbench and is predicted on the existence of Network Execution Platform.,The Network Execution Platform is a network computer that performs network functions necessary to execute typical services. Its operating system provides access to telecommunication and computing functionality. The Software Assembly Workbench is based on two adjacent software layers, the Service (upper) layer and the Computer (intermediate) layer.,These two layers require the implementation of a third (lower) layer, the Capability layer, which resides on the Network Execution Platform, the Software constructed using the two layers of the Software Assembly Workbench is first verified through Simulation. Both the execution platform and the application software are instrumented for failure detection and management.,The uniqueness of this approach resides in our ability to rapidly create software that can be dependably executed in a distributed telecommunication network.,软件装配平台:如何像构造硬件那样构造软件。本文描述了一个像设计硬件那样, 通过将可用组件块结合起来以装配软件的方法。这一方法利用软件装配平台并且需要网络执行平台。网络执行平台是一台网络计算机，它能执行完成典型服务所必须的网络功能。,其操作系统提供了对远程通讯和计算功能性的访问。软件装配平台以两个相邻的软件层为基础，即服务程序（上）层和计算机（中间）层。这两层都要求第三（低）层的实现，即权能层。它归属于网络执行平台。用软件装配平台的这两层构造的软件要先通过模拟检验。提供执行平台和应用软件都是为了用于错误检测和管理的。这一方法的独到之处在于能够快速生成可在分布式远程通讯网上可靠执行的软件。,empirical,em5pIrIk(E)l Relying on or derived from observation or experiment 经验的, 依据观察或实验或由观察或试验得出的 theoretical,assembly,E5semblI n.集合, 装配, 集会, 集结, 汇编,workbench,工作台,building block,n.(儿童游戏用的)积木; 构件块,构件,组成部件,积木构件,标准组件. In software engineering, an individual unit or module that is utilized by higher-level programs or modules. 在软件工程中,指较高一级程序或模块使用的一个单元或模块。,predict,To state, tell about, or make known in advance, especially on the basis of special knowledge. 预测，预知，预告预先陈述、告诉或公布，尤指以特殊知识为基础,service,5sE :vis 服务(程序),业务 In network architecture, the capabilities that a layer provides to the adjacent layer closer to the end user. 在网络体系结构中,某一层向接近于最终 用户的相邻层提供的(服务)能力。,functionality,9fQNkFEn5Aliti功能性 A computer industry term for what the hardware or software can do. 一种计算机工业用语,用于说明计算机硬件或软件能做什么样的工作。,implementation,implimen5teiFLn实现施 In system development,the realization of a system design in hardware, software,or both. 在系统开发过程中,用硬件、软件或其两者对一个系统设计的具体实现。,capability,9keipE5biliti能力,权能 Permission which the user process must possess for the object in order to carry out an operation on the object (i.e. to retrieve a file). 系统为执行一种对象操作(如检索一个文件)时,用户进程必须具有完成该作业的许可。,uniqueness,ju:5ni:knisn.唯一性; 单值性; 独特性,dependable,dI5pendEb(E)ladj.可靠的 dependent adj.依靠的, 依赖的, 由.决定的, 随.而定的,A BRIEF INTRODUCTIN TO THE INTERNET,DANIEL B.DAVISON and EDWARD CHEN Department of Biochemical and Biophysical Sciences and Computer Science, BCHS-5934 University of Houston, 4800 Calhoun, Houston, TX 77203-5934, U. S. A. e-mail: (Received 11 November 1994; accepted 30 November 1994),AbstractThe Internet has changed the way science is performed. The upcoming changes to the Internet will change the way we live. The article will examine briefly the internet, how it got to where it is, and where it might be going. Key words: Internet, Ipng, Gopher, World Wide Web, WAIS,The early days,The rationale for the Net The Internet began with the concern of the U. S. Department of Defense that command communications were too fragile. At the time (the late 1960s) all telecommunications were strictly point-to-point. A message destined for a defense facility in Chicago might have to pass through Washington, Baltimore, Philadelphia, Pittsburgh, and Cincinnati to get to Chicago.,Under this system, any national disaster such as a nuclear war, or local emergency (e.g. weather) in any of the intermediate sites could stop communications with Chicago. A communications system that was decentralized and contained redundant pathways for messages clearly was needed, but the computer science and electronics of the time were not yet up to the task.,Building on some theoretical work of the mid-1960s and advances in semiconductor fabrication in the early 1970s, the first processors implementing a distributed communications system were set up in the mid-1970s (Cerf. 1993a, 1993b). This decentralization had crucial effects on the growth of the Internet.,The name for the way computers talk to each other is a “protocol”. As in experiment science, a communications protocol is a defined series of steps. The protocol designed for the Internet is known as “packet-switching”. A series of characters to be transmitted from one computer to another is broken up into “envelops” termed packets.,Packet-switching,Each packet has on it an address to which it is going and the address that it is from, exactly the same as the letter. The addresses and some other information are termed the header; the series characters to be transmitted are termed the data. Included in the header is a sequence number, which indicates how the packet is to be reassembled at the destination computer.,The minimum packet size on the Internet, not including the header, is 56 bytes, but packets can be larger if the computers talking to each other agree on a larger packet size. The packet-switching protocol used on the ARPANET came to be termed the Transmission Control Protocol, TCP. A large number of machines on the same physical network can talk to each other this way.,Soon after the development of TCP, the problem of connecting net works arose. A new protocol was needed, the Internet Protocol (IP). It is from this protocol that the Internet gets its name. The two protocols are interwound so completely that the set is termed the TCP/IP protocols.,The hardware basis of the Internet is the router, a high-speed computer that reads the source and destination addresses of every packet on the network. From that and other information, the router calculates a least cost route for each packet and sends the packet on its way. The least cost route may change from minute to minute-one packet from MIT to Stanford may go through Chicago and next go through Houston.,Routers and Iraq,It is the responsibility of the destination machine to put the packets together in the correct sequence when they arrive, or ask for them to be retransmitted if they do not. Luckily, the Internet in the U.S.A. has never been tested in a wartime situation. The Defense Department recently determined rather unexpectedly that the ideas do work, however.,During the Gulf War, despite numerous direct hits on Iraqi command and control sites, and bridges thought to carry network hardware (i.e. fiber optic cables) the Iraqi data network remained working. After the war, it was revealed that the network was TCP/IP based and used the same equipment that runs the Internet. It is illegal now to export routers to certain countries from the U.S.A.,As with any other good tool, the TCP/IP protocols provided a base for the development of many other tools. In this situation TCP/IP is chassis, and the other protocols built on it are the cars, trucks, and luxury vehicle of the Internet. ,Telnet, FTP, e-mail,The growth of the Internet-decentralization The Internet began with a few machines in the late 1970s, grew to hundreds by early 1980s, and now numbers at least several hundred-thousand machines. Its growth is charted in Figure 1 (Quarterman, Philips, and Carl-Mitchell, 1994). ,At present the Internet in North American is series of regional networks interconnected by T3 communications lines, with each T3 line having a bandwidth (analogous to total speed) of 45Mbits/sec. To put this in perspective, a T3 line can support approximately 140 voice channels. ,The situation today,New tools The Internet has expanded greatly in the past two years. A large part of the expansion was the result of many small local Internet providers and large computer service organizations such as CompuServe, America Online, and Delphi using the Internet. ,The first of the new tools was Gopher (Anklesaria and others, 1992), designed at the University of Minnesota as a campus-wide information system. It made clever use of existing Internet protocols to expand greatly their utility. ,Gopher,The atomic unit in FTP is the file. In Gopher, it is the content of the file. The WWW (Berners Lee, 1993a) began as a project of the high-energy physics community centered at CERN to share data worldwide. ,The World Wide Web (WWW),The protocol that underlines the WWW (also know as the Web) is HTTP (Berners-Lee, 1993a). As a part of the protocol, the concept of the URL was widely introduced (Berners-Lee, 1994). A URL is composed of three parts. ,Hypertext Transport protocol (HTTP) and Uniform Resource Locators (URLs),Classes of service The most outstanding change coming to the Internet will be the oft-requested charging, as is done on CompuServe or American OnLine. This could change dramatically the nature of the Internet but would speed up its growth. ,THE FUTURE OF THE INTERNET,One of the exciting technologies now being developed is a software robot that can follow HTTP links by itself. The user gives the program a keyword of interest and a starting point. ,Spiders and web-walkers,The address space of the Internet is 231-1 or 4.3 billion addresses. Because of conventions about numbers, the actual address space is smaller. ,Internet protocol-next generation (Ipng),Any good technology, by definition, defines prediction and makes the prognosticator seem foolish. A high official with IBM is said to have commented in the 1950s that they could sell at most 100 computer before exhausting the market. Thus, even those who develop the technology cannot envision even a small number of its users.,WHERE IS THE NET GOING ?,upcoming,Qp5kQmIN adj.即将来临的, 预定将要,destine,5destIn To direct toward a given destination: 朝着, 朝着一个给定的目的地：,command,The act of commanding.,rationale,rAFE5nB:l; (?) -5nAl; 7rAFE5nB:li n.基本原理,根本原因；最基本的原因；基础 rational adj.理性的, 合理的, 推理的 n.数有理数,redundant,rI5dQndEnt adj.多余的 Of or involving redundancy in electronic equipment. 冗余的,电子设备或涉及电子设备中冗余的 Of or involving redundancy in the transmission of messages. 冗余的,传输信息中或涉及传输信息中冗余的,crucial,5kru:F(E)ladj. 至关紧要的, 极其重要的确,决定性的;十字形的.,packet,5pAkIt n.小包裹, 小捆 v.包装 信息包,protocol,5prEutEkCl 协议,规程,规约;议定 A set of semantic and syntactic rules that determines the behavior of functional units in achieving communication. 一组语义和语法规则,决定功能部件在通信时如何进行工作。 A specification for the format and relative timing of information exchanged between communicating parties. 通信双方之间交换信息的格式和相对定时同步的一种规范。,ARPANET,ARPA: abbr. Advanced Research Projects Agency (美国国防部)高级研究计划署,interwind,9IntEwaInd v.互卷,互相盘绕,route,ru:t n.路线, 路程, 通道;路由 v.发送 router计 路由器(读取每一个数据包中的地址然后决定如何传送的专用,智能性的网络设备,unexpected,QnIk5spektId adj.想不到的, 意外的, 未预料到,chassis,5FAsI n.底盘,框架,T3,计传输速率可达44.736Mb/s的通讯线路,perspective,pE5spektIv n.透视画法, 透视图, 远景, 前途, 观点, 看法, 观点, 观察,analogous,E5nAlEEs adj.类似的, 相似的, 可比拟的; 模拟的,utility,ju:5tiliti 应用程序; 效用,oft,5C:ft adv.常常, 再三,community,kE5mju:nItI n.公社, 团体, 社会, (政治)共同体, 共有, 一致, 共同体, (生物)群落 institute, society, association, union,CERN,abbr. European laboratory for particle physics 欧洲粒子物理实验室 CERN =法 Conseil Europeen pour la Recherche Nucleaire 欧洲原子核研究委员会,underlie,QndE5laI vt.位于.之下, 成为.的基础,charge,tFB:dV n.负荷, 电荷, 费用, 主管, 掌管, 充电, 充气, 装料 v.装满, 控诉, 责令, 告诫, 指示, 加罪于, 冲锋, 收费,CompuServe,美国最大的在线信息服务机构之一,spider,5spaIdE(r) n.蜘蛛, 设圈套者, 三脚架,convention,kEn5venFEnn. （政治、宗教、政党等的）会议， 大会； 全国性大会； 召集， 集会; 协议,条约,规定,约定,规范, 公约;常规, 习俗, 惯例,define,详细说明,prognosticator, prCnCstIkeItE(r) n.预言者, 占卜者,envision,in5viVEnvt. 想象; 预见; 展望,Incremental Fuzzy Expert PID Control,AbstractThis paper presents an approach to intelligent PID control of industrial systems, which is based on the application of fuzzy logic. This approach assumes that one available nominal controller parameter settings through some classical tuning technique (Ziegler-Nichols, Kalman, etc.).,By using an appropriate fuzzy matrix (which is similar to Macvicar-Whelan matrix), we determine small changes on these values during the system operation, and these lead to improved performance of transient and steady behavior of the close-loop system. This is achieved at the expense of some small extra computational effort, which can be very easily undertaken by a microprocessor.,Several experimental results illustrate the improvements achieved. KeywordsPID control, controller tuning, intelligent control, fuzzy logic, fuzzy control, Ziegler-Nichols technique, Kalman PID tuning, fuzzy control matrix.,增量模糊专家PID控制 摘要本文给出了一个以模糊逻辑应用为基础的用于工业系统智能PID控制的方法。该方法的实现，以可通过一些经典的整定技术进行控制器的标称参数设置为前提。通过利用适当的模糊矩阵，可确定这些值在系统运行时的较小变化，并改善闭环系统的瞬态和稳态特性。这需要可由微处理器轻松完成的少量额外计算来实现。若干实验结果印证了所获改善。,1. INTRODUCTION,PROPORTIONAL plus integral plus derivative (PID) control is a well-established and popular technique for industrial process control. This is due to its simplicity both from the design and the parameter tuning point of view. However, the capabilities of PID controllers are limited and much research was, and is being, carried out to enhance them in various ways (e.g., by embedding adaptivity and robustness properties. etc.) 1.,The purpose of this paper is to improve the performance of such analog and digital PID controllers by using experimenta1 rules (intelligence) based on fuzzy logic. Through small changes of the values of the three coefficients of the controllers (which are determined by classical tuning procedures) on the basis of fuzzy matrix that contains, in condensed rule form, the experience of human-controller, we obtain considerable improvement of the performance of the controller (smaller overshoot, faster response, and so on).,Of course, this is obtained at the expense of some add