毕业设计外文翻译

金融体制、融资约束与投资——来自OECD的实证分析R．SemenovDepartment of Economics，University of Nijmegen，Nijmegen（荷兰内梅亨大学，经济学院）这篇论文考查了OECD的11个国家中现金流量对企业投资的影响.我们发现不同国家之间投资对企业内部可获取资金的敏感性具有显著差异,并且银企之间具有明显的紧密关系的国家的敏感性比银企之间具有公平关系的国家的低.同时，我们发现融资约束与整体金融发展指标不存在关系.我们的结论与资本市场信息和激励问题对企业投资具有重要作用这种观点一致，并且紧密的银企关系会减少这些问题从而增加企业获取外部融资的渠道。

一、引言各个国家的企业在显著不同的金融体制下运行。

金融发展水平的差别(例如，相对GDP的信用额度和相对GDP的相应股票市场的资本化程度），在所有者和管理者关系、企业和债权人的模式中，企业控制的市场活动水平可以很好地被记录.在完美资本市场,对于具有正的净现值投资机会的企业将一直获得资金。

然而，经济理论表明市场摩擦，诸如信息不对称和激励问题会使获得外部资本更加昂贵，并且具有盈利投资机会的企业不一定能够获取所需资本.这表明融资要素，例如内部产生资金数量、新债务和权益的可得性，共同决定了企业的投资决策.现今已经有大量考查外部资金可得性对投资决策的影响的实证资料（可参考，例如Fazzari（1998）、 Hoshi(1991)、 Chapman（1996）、Samuel(1998））.大多数研究结果表明金融变量例如现金流量有助于解释企业的投资水平。

这项研究结果解释表明企业投资受限于外部资金的可得性。

很多模型强调运行正常的金融中介和金融市场有助于改善信息不对称和交易成本，减缓不对称问题,从而促使储蓄资金投着长期和高回报的项目,并且提高资源的有效配置（参看Levine（1997)的评论文章）。

因而我们预期用于更加发达的金融体制的国家的企业将更容易获得外部融资.几位学者已经指出建立企业和金融中介机构可进一步缓解金融市场摩擦。

1 工程概论1.1 工程专业1.2 工业和技术1.3 现代制造业工程专业1 工程行业是历史上最古老的行业之一。

如果没有在广阔工程领域中应用的那些技术，我们现在的文明绝不会前进。

第一位把岩石凿削成箭和矛的工具匠是现代机械工程师的鼻祖。

那些发现地球上的金属并找到冶炼和使用金属的方法的工匠们是采矿和冶金工程师的先祖。

那些发明了灌溉系统并建造了远古世纪非凡的建筑物的技师是他们那个时代的土木工程师。

2 工程一般被定义为理论科学的实际应用，例如物理和数学。

许多早期的工程设计分支不是基于科学而是经验信息，这些经验信息取决于观察和经历，而不是理论知识。

这是一个倾斜面实际应用的例子，虽然这个概念没有被确切的理解，但是它可以被量化或者数字化的表达出来。

3 从16、17世纪当代初期，量化就已经成为科学知识大爆炸的首要原因之一。

另外一个重要因素是实验法验证理论的发展。

量化包含了把来源于实验的数据和信息转变成确切的数学术语。

这更加强调了数学是现代工程学的语言。

4 从19世纪开始，它的结果的实际而科学的应用已经逐步上升。

机械工程师现在有精确的能力去计算来源于许多不同机构之间错综复杂的相互作用的机械优势。

他拥有能一起工作的既新型又强硬的材料和巨大的新能源。

工业革命开始于使用水和蒸汽一起工作。

从此使用电、汽油和其他能源作动力的机器变得如此广泛以至于它们承担了世界上很大比例的工作。

5 科学知识迅速膨胀的结果之一就是科学和工程专业的数量的增加。

到19世纪末不仅机械、土木、矿业、冶金工程被建立而且更新的化学和电气工程专业出现了。

这种膨胀现象一直持续到现在。

我们现在拥有了核能、石油、航天航空空间以及电气工程等。

每种工程领域之内都有细分。

6 例如，土木工程自身领域之内有如下细分：涉及永久性结构的建筑工程、涉及水或其他液体流动与控制系统的水利工程、涉及供水、净化、排水系统的研究的环境工程。

机械工程主要的细分是工业工程，它涉及的是错综复杂的机械系统，这些系统是工业上的，而非单独的机器。

毕业设计(论文）外文文献翻译院系：财务与会计学院年级专业：201＊级财务管理姓名:学号：132148*＊*附件: 财务风险管理【Abstract】Although financial risk has increased significantly in recent years risk and risk management are not contemporary issues。

The result of increasingly global markets is that risk may originate with events thousands of miles away that have nothing to do with the domestic market。

Information is available instantaneously which means that change and subsequent market reactions occur very quickly。

The economic climate and markets can be affected very quickly by changes in exchange rates interest rates and commodity prices。

Counterparties can rapidly become problematic。

As a result it is important to ensure financial risks are identified and managed appropriately. Preparation is a key component of risk management。

【Key Words】Financial risk，Risk management，YieldsI. Financial risks arising1.1What Is Risk1.1.1The concept of riskRisk provides the basis for opportunity. The terms risk and exposure have subtle differences in their meaning. Risk refers to the probability of loss while exposure is the possibility of loss although they are often used interchangeably。

毕业设计外文文献翻译专业学生姓名班级学号指导教师优集学院外文资料名称：Knowledge-Based Engineeri--ng Design Methodology外文资料出处：Int.J.Engng Ed.Vol.16.No.1附件： 1.外文资料翻译译文2.外文原文基于知识工程(KBE)设计方法D. E. CALKINS1.背景复杂系统的发展需要很多工程和管理方面的知识、决策，它要满足很多竞争性的要求。

设计被认为是决定产品最终形态、成本、可靠性、市场接受程度的首要因素。

高级别的工程设计和分析过程(概念设计阶段)特别重要，因为大多数的生命周期成本和整体系统的质量都在这个阶段。

产品成本的压缩最可能发生在产品设计的最初阶段。

整个生命周期阶段大约百分之七十的成本花费在概念设计阶段结束时，缩短设计周期的关键是缩短概念设计阶段，这样同时也减少了工程的重新设计工作量。

工程权衡过程中采用良好的估计和非正式的启发进行概念设计。

传统CAD工具对概念设计阶段的支持非常有限。

有必要，进行涉及多个学科的交流合作来快速进行设计分析(包括性能，成本，可靠性等)。

最后，必须能够管理大量的特定领域的知识。

解决方案是在概念设计阶段包含进更过资源，通过消除重新设计来缩短整个产品的时间。

所有这些因素都主张采取综合设计工具和环境，以在早期的综合设计阶段提供帮助。

这种集成设计工具能够使由不同学科的工程师、设计者在面对复杂的需求和约束时能够对设计意图达成共识。

那个设计工具可以让设计团队研究在更高级别上的更多配置细节。

问题就是架构一个设计工具，以满足所有这些要求。

2.虚拟(数字)原型模型现在需要是一种代表产品设计为得到一将允许一产品的早发展和评价的真实事实上原型的过程的方式。

虚拟样机将取代传统的物理样机，并允许设计工程师，研究“假设”的情况，同时反复更新他们的设计。

真正的虚拟原型，不仅代表形状和形式，即几何形状，它也代表如重量，材料，性能和制造工艺的非几何属性。

（Sheaｒ waｌl ｓt ｒuctural desigｎ ofh ｉgh-ｌev ｅl fr ａmeworkＷｕ Jiche ｎgＡbstract ： In t ｈis pape ｒ the basic c ｏｎcepts of ｍａn ｐow ｅr ｆｒom th ｅ ｆra ｍｅ sh ｅａr w ａｌl str ｕc ｔｕｒｅ, analy ｓis of the ｓtruct ｕr ａｌ des ｉgn ｏf th ｅ c ｏnt ｅnt ｏｆ t ｈe fr ａme she ａr wall, in ｃｌudi ｎg the ｓeism ｉc wa ｌl she ａr spa本科毕业设计外文文献翻译学校代码： 10128学 号：题 目：Shear wall structural design of high-level framework 学生姓名： 学 院：土木工程学院 系 别：建筑工程系 专 业：土木工程专业（建筑工程方向） 班 级：土木08-（5）班 指导教师： (副教授)ｎratiｏdesign, ａnd a concrｅtｅｓtruｃtuｒe in thｅmｏst co ｍmonｌy useｄframe shear walｌstｒｕcturｅtｈｅdesign of p ｏiｎｔs to note.Keyworｄs: cｏncrｅｔｅ; fｒaｍｅshｅａｒwall sｔｒucｔｕre；hiｇh－risｅbuildｉｎｇsThe wall is aｍoｄern high－rｉｓe buiｌdiｎgs is an iｍpo ｒｔant buiｌdinｇconｔｅnt, the ｓize of thｅfraｍe sheａr wall must comｐly with buildｉng reguｌａtｉons. The pｒｉnｃipｌe is ｔhat the largeｒsｉzｅbｕt the thｉｃknessｍuｓt ｂｅsmaller gｅoｍetric featｕrｅｓshoｕlｄｂe ｐｒeｓented ｔo the pｌatｅ,ｔｈe forｃe is close to cylｉndrｉcal.Ｔhe waｌl sｈｅar wa ｌl strｕｃｔure ｉs a flaｔcomｐonent. Itｓeｘposure to tｈe force aｌoｎg ｔhe ｐlane leｖｅl of theｒole ofｓｈear and momｅｎt, must also take ｉｎtｏａccounｔthe veｒｔical preｓsure.Opeｒate unｄer thｅcomｂiｎed actｉｏn oｆbenｄing momeｎts and axial force aｎｄsheａr forcｅbｙthe caｎtilｅｖｅr deep beａm uｎder ｔｈe acｔion of the force leveｌｔo lｏo ｋinto ｔｈe bottom mouｎted on ｔhe basｉs of. Sheaｒｗaｌl ｉｓdiｖidｅｄinｔo a whole walｌand ｔheａssoｃiated ｓｈeａr wall in thｅactual project,a wholｅwａlｌfor ｅxａmpl ｅ, suｃh as ｇenｅraｌhｏusiｎｇｃonstｒuction in tｈe gablｅｏr fish bｏne strｕcture ｆｉlｍwａｌls ａnd small opｅningｓwall.Cｏupled Sｈeａr ｗalls are ｃonnｅcted bｙｔhｅcｏupｌing ｂeam shｅａr wall.Buｔｂecause tｈeｇｅnerａlｃｏupling beaｍstｉｆfness is less thaｎｔhe wall stiｆfnｅsｓof the lｉmbs，ｓｏ. Wａlｌliｍb aｌonｅis obviｏus.The ｃｅntral beam of tｈeｉnflｅｃtion pｏｉnｔtｏpay aｔtenｔiｏｎto tｈeｗaｌl pressｕre thａn the limiｔs of the lｉmb axis. Will forｍa shortｗiｄe beａms，widｅcolｕmn wａll liｍｂｓhear wａll ｏpｅnings toｏlarge ｃomｐonｅnt aｔbothｅn ｄs ｗith jｕst the domain of vａｒiabｌe crosｓ－ｓecｔｉon ro ｄin ｔhe intｅrｎａｌforcｅｓｕnder tｈｅaｃtioｎof maｎy Ｗalｌlｉmb iｎflｅcｔion point Ｔhｅｒeｆoｒe, ｔhe cａｌcula ｔions ａｎd consｔruction sｈouldAccordinｇtｏappｒoxiｍａｔe tｈe framｅstｒucｔure to ｃonsideｒ.Tｈe desｉｇｎof ｓhｅａr walls ｓhoulｄbe based on the cｈａractｅrisｔics ｏf ａvａｒｉｅty oｆwall itseｌｆ,ａnd dｉfferｅnｔmeｃhanical ch ａrａcteｒisｔｉcｓand requireｍents,wall oｆthｅinternａｌforceｄistrｉbutｉon and failurｅmoｄｅs ｏf sｐecific and cｏmprehensive ｃonｓideration of the design rｅinｆorcemｅnt aｎd stｒuctural measｕres. Ｆrame sｈear wall ｓｔrｕctuｒe deｓiｇn is to cｏｎsider the ｓtructｕre of the oｖerall ａnａｌysis for ｂoｔh dｉrecｔｉｏｎsｏｆthｅhｏrｉzontal and vｅrtiｃalｅfｆects. Oｂtain thｅinternal force ｉs reｑuirｅd in ａccｏrdancｅｗｉｔｈtｈe bias or paｒtｉal ｐull normal sｅcｔｉon forｃｅｃaｌculatiｏn.The waｌl strｕcture oｆtheｆｒame sｈear ｗall ｓｔructural dｅsign of ｔhe coｎtent frame hｉgh-rise buildings, in ｔhe actual ｐrｏjeｃｔiｎｔhｅuse of thｅｍoｓt seisｍic ｗａlls have suffiｃient quantitｉeｓto meｅt ｔheｌｉmitsｏf the lａyer displacement, the loｃation iｓｒelａtiｖely flexiblｅ. Seiｓmic wａll for cｏntinuous layout，ｆulｌ-length ｔhroｕgh．Should bｅdesigned to avoid the waｌl mutaｔioｎs ｉn limb ｌｅｎgth and alignment is noｔuｐａnd down the ｈolｅ. The samｅtｉme．Tｈe inｓide of ｔhe hole marginｓcｏlｕｍｎshｏｕld not ｂｅｌｅssｔhan３00mm ｉｎordｅｒtｏguaraｎteｅtheｌengtｈof the colｕｍn ａs the edgｅof tｈe coｍponent and constｒａiｎt eｄgｅcｏｍponeｎts．Thｅbi-direc ｔiｏnal laｔerａl forｃe ｒesiｓting strucｔurａl fｏrm of verticａl aｎｄhorｉzontaｌwalｌcoｎnected.Eａｃh ｏｔhｅr as ｔhe ａffiｎiｔｙof the shｅar wall. Ｆor ｏnｅ, two seismic frａme sｈe ａr ｗalｌｓ,ｅｖen beam highｒatio ｓhould noｔgreateｒthan 5 aｎd a height of nｏt less thaｎ400mm.Midline colｕmnａnd beａmｓ,wall ｍｉdline shouｌdｎoｔbe greaｔer tha ｎthe ｃoｌｕmｎwidｔｈof1/4，ｉn ordｅr ｔｏreｄuce thｅtoｒsional eｆfect of the sｅiｓmｉｃacｔion ｏnｔｈｅｃolｕmn．Oｔhｅrwｉsｅcan be taken tｏstrengthｅn theｓtirruprａｔｉo iｎｔhe cｏlｕmn tｏmake ｕp.If thｅshear wａｌl sheａｒsｐａn ｔhａnｔhe ｂig twｏ. Ｅveｎthe beａｍcro ｓs-heｉｇht ratiｏgreateｒthan 2.5, ｔhen tｈe design presｓｕｒe ｏf thｅｃｕt shoulｄnoｔmａkｅａｂig 0.2. Howevｅｒ, ｉf the sheａｒwallｓheａr sｐａｎｒatiｏof ｌess than two couｐlinｇｂeａms sｐan of ｌeｓs than ２．5, then the shear coｍｐres ｓiｏn rａｔiｏis noｔgreaｔer thａn 0.15. Thｅｏther haｎｄ，ｔhe bｏttom oｆthe fraｍe ｓhｅar walｌstructure ｔo enhａnce tｈｅdｅsign sｈould ｎoｔbe leｓs thaｎ２０0mmａnd noｔlesｓthaｎstorey 1/１6，othｅｒｐaｒtｓｓhｏulｄnot be lｅss than 160mm ａnd ｎｏt ｌｅss thaｎｓtoｒey １/20. Arounｄthe wall of the frame ｓhｅar ｗall strucｔure sｈｏulｄbe set ｔo the beａm or dark bｅamａnd the sｉｄe columｎｔｏform a borｄｅr. Ｈoｒizｏntａl ｄｉｓtrｉbuｔioｎoｆsｈear waｌls cａn from the sheａr effect，tｈｉs design wｈen ｂuilｄｉng higｈｅr longeｒor fｒaｍｅｓtructｕre reinfoｒcｅment shｏuld be aｐprｏpｒiatelｙincｒeａｓed, ｅspｅcｉａlｌy in the sｅnｓitivｅｐarts of the beam pｏsition ｏr teｍperaｔuｒe, stiffnｅsｓchａnge is besｔappｒopriatｅly increased, ｔｈeｎcｏnsidｅration sｈoulｄbe ｇｉveｎｔo the wａlｌvertｉcaｌreiｎforｃemeｎt,becaｕse ｉt is mａinly fｒom the bｅnding efｆecｔ, aｎｄtake in ｓome ｍｕlti-ｓtorｅｙshｅａｒｗａll structuｒereinforcｅｄreｉnｆorceｍent rate -likｅlｅsｓconｓtｒained edgｅｏｆｔhｅcomｐonent or components reinforｃemeｎt of thｅedge ｃomｐｏnent.Referｅnces: [1 sad Hａyaｓhi,He Yaming. Ｏn the shorｔshｅar ｗall ｈigh-riｓe bｕilｄinｇｄesign ［J]．Kｅｙｕaｎ, 2008, (O2).高层框架剪力墙结构设计吴继成摘要: 本文从框架剪力墙结构设计的基本概念人手, 分析了框架剪力墙的构造设计内容, 包括抗震墙、剪跨比等的设计, 并出混凝土结构中最常用的框架剪力墙结构设计的注意要点。

毕业设计（论文）外文参考文献翻译计算机科学与信息工程系系（院）2008 届题目企业即时通Instant Messaging for Enterprises课题类型技术开发课题来源自选学生姓名许帅专业班级 04计算机科学与技术指导老师王占中职称工程师完成日期：2008年4 月 6 日目录I NSTANT M ESSAGING FOR E NTERPRISE (1)1. Tips (1)2. Introduction (1)3. First things first (2)4.The While-Accept loop (4)5. Per-Thread class (6)6. The Client class (7)企业即时通 (9)1.提示 (9)2.简介 (9)3.首先第一件事 (10)4.监听循环 (11)5.单线程类 (13)6.用户端类 (14)Instant Messaging for Enterprise1. TipsIf Java is, in fact, yet another computer programming language, you may question why it is so important and why it is being promoted as a revolutionary step in computer programming. The answer isn’t immediately obvious if you’re coming from a tr aditional programming perspective. Although Java is very useful for solving traditional standalone programming problems, it is also important because it will solve programming problems on the World Wide Web. What is the Web?The Web can seem a bit of a mys tery at first, with all this talk of “surfing,”“presence,” and “home pages.” It’s helpful to step back and see what it really is, but to do this you must understand client/server systems, another aspect of computing that is full of confusing issues. The primary idea of a client/server system is that you have a central repository of information，some kind of data, often in a database。

毕业设计外文资料翻译学院：信息科学与工程学院专业：软件工程姓名： XXXXX学号： XXXXXXXXX外文出处： Think In Java (用外文写)附件： 1.外文资料翻译译文；2.外文原文。

附件1：外文资料翻译译文网络编程历史上的网络编程都倾向于困难、复杂，而且极易出错。

程序员必须掌握与网络有关的大量细节，有时甚至要对硬件有深刻的认识。

一般地，我们需要理解连网协议中不同的“层”（Layer）。

而且对于每个连网库，一般都包含了数量众多的函数，分别涉及信息块的连接、打包和拆包；这些块的来回运输；以及握手等等。

这是一项令人痛苦的工作。

但是，连网本身的概念并不是很难。

我们想获得位于其他地方某台机器上的信息，并把它们移到这儿；或者相反。

这与读写文件非常相似，只是文件存在于远程机器上，而且远程机器有权决定如何处理我们请求或者发送的数据。

Java最出色的一个地方就是它的“无痛苦连网”概念。

有关连网的基层细节已被尽可能地提取出去，并隐藏在JVM以及Java的本机安装系统里进行控制。

我们使用的编程模型是一个文件的模型；事实上，网络连接（一个“套接字”）已被封装到系统对象里，所以可象对其他数据流那样采用同样的方法调用。

除此以外，在我们处理另一个连网问题——同时控制多个网络连接——的时候，Java内建的多线程机制也是十分方便的。

本章将用一系列易懂的例子解释Java的连网支持。

15.1 机器的标识当然，为了分辨来自别处的一台机器，以及为了保证自己连接的是希望的那台机器，必须有一种机制能独一无二地标识出网络内的每台机器。

早期网络只解决了如何在本地网络环境中为机器提供唯一的名字。

但Java面向的是整个因特网，这要求用一种机制对来自世界各地的机器进行标识。

为达到这个目的，我们采用了IP（互联网地址）的概念。

IP以两种形式存在着：(1) 大家最熟悉的DNS（域名服务）形式。

我自己的域名是。

所以假定我在自己的域内有一台名为Opus的计算机，它的域名就可以是。

南京理工大学紫金学院毕业设计（论文）外文资料翻译系：机械系专业：车辆工程专业姓名:宋磊春学号:070102234外文出处：EDU_E_CAT_VBA_FF_V5R9(用外文写)附件：1。

外文资料翻译译文；2.外文原文.附件1：外文资料翻译译文CATIA V5 的自动化CATIA V5的自动化和脚本：在NT 和Unix上：脚本允许你用宏指令以非常简单的方式计划CATIA。

CATIA 使用在MS –VBScript中(V5.x中在NT和UNIX3。

0 )的共用部分来使得在两个平台上运行相同的宏。

在NT 平台上：自动化允许CATIA像Word/Excel或者Visual Basic程序那样与其他外用分享目标。

ATIA 能使用Word/Excel对象就像Word/Excel能使用CATIA 对象。

在Unix 平台上:CATIA将来的版本将允许从Java分享它的对象。

这将提供在Unix 和NT 之间的一个完美兼容。

CATIA V5 自动化：介绍（仅限NT）自动化允许在几个进程之间的联系:CATIA V5 在NT 上：接口COM：Visual Basic 脚本(对宏来说)，Visual Basic 为应用（适合前:Word/Excel )，Visual Basic。

COM（零部件目标模型)是“微软“标准于几个应用程序之间的共享对象。

Automation 是一种“微软“技术,它使用一种解释环境中的COM对象。

ActiveX 组成部分是“微软“标准于几个应用程序之间的共享对象,即使在解释环境里。

OLE（对象的链接与嵌入）意思是资料可以在一个其他应用OLE的资料里连结并且可以被编辑的方法(在适当的位置编辑）.在VBScript,VBA和Visual Basic之间的差别：Visual Basic(VB）是全部的版本。

它能产生独立的计划,它也能建立ActiveX 和服务器。

它可以被编辑。

VB中提供了一个补充文件名为“在线丛书“(VB的5。

软件工程专业毕业设计外文文献翻译1000字本文将就软件工程专业毕业设计的外文文献进行翻译，能够为相关考生提供一定的参考。

外文文献1: Software Engineering Practices in Industry: A Case StudyAbstractThis paper reports a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The study investigated the company’s software development process, practices, and techniques that lead to the production of quality software. The software engineering practices were identified through a survey questionnaire and a series of interviews with the company’s software development managers, software engineers, and testers. The research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company follows a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The findings of this study provide a valuable insight into the software engineering practices used in industry and can be used to guide software engineering education and practice in academia.IntroductionSoftware engineering is the discipline of designing, developing, testing, and maintaining software products. There are a number of software engineering practices that are used in industry to ensure that software products are of high quality, reliable, and maintainable. These practices include software development processes, software configuration management, software testing, requirements engineering, and project management. Software engineeringpractices have evolved over the years as a result of the growth of the software industry and the increasing demands for high-quality software products. The software industry has developed a number of software development models, such as the Capability Maturity Model Integration (CMMI), which provides a framework for software development organizations to improve their software development processes and practices.This paper reports a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The objective of the study was to identify the software engineering practices used by the company and to investigate how these practices contribute to the production of quality software.Research MethodologyThe case study was conducted with a large US software development company that produces software for aerospace and medical applications. The study was conducted over a period of six months, during which a survey questionnaire was administered to the company’s software development managers, software engineers, and testers. In addition, a series of interviews were conducted with the company’s software development managers, software engineers, and testers to gain a deeper understanding of the software engineering practices used by the company. The survey questionnaire and the interview questions were designed to investigate the software engineering practices used by the company in relation to software development processes, software configuration management, software testing, requirements engineering, and project management.FindingsThe research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company’s software development process consists of five levels of maturity, starting with an ad hoc process (Level 1) and progressing to a fully defined and optimized process (Level 5). The company has achieved Level 3 maturity in its software development process. The company follows a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The software engineering practices used by the company include:Software Configuration Management (SCM): The company uses SCM tools to manage software code, documentation, and other artifacts. The company follows a branching and merging strategy to manage changes to the software code.Software Testing: The company has adopted a formal testing approach that includes unit testing, integration testing, system testing, and acceptance testing. The testing process is automated where possible, and the company uses a range of testing tools.Requirements Engineering: The company has a well-defined requirements engineering process, which includes requirements capture, analysis, specification, and validation. The company uses a range of tools, including use case modeling, to capture and analyze requirements.Project Management: The company has a well-defined project management process that includes project planning, scheduling, monitoring, and control. The company uses a range of tools to support project management, including project management software, which is used to track project progress.ConclusionThis paper has reported a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The study investigated the company’s software development process,practices, and techniques that lead to the production of quality software. The research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company uses a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The findings of this study provide a valuable insight into the software engineering practices used in industry and can be used to guide software engineering education and practice in academia.外文文献2: Agile Software Development: Principles, Patterns, and PracticesAbstractAgile software development is a set of values, principles, and practices for developing software. The Agile Manifesto represents the values and principles of the agile approach. The manifesto emphasizes the importance of individuals and interactions, working software, customer collaboration, and responding to change. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases. This paper presents an overview of agile software development, including its principles, patterns, and practices. The paper also discusses the benefits and challenges of agile software development.IntroductionAgile software development is a set of values, principles, and practices for developing software. Agile software development is based on the Agile Manifesto, which represents the values and principles of the agile approach. The manifesto emphasizes the importance of individuals and interactions, working software, customer collaboration, and responding to change. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases.Agile Software Development PrinciplesAgile software development is based on a set of principles. These principles are:Customer satisfaction through early and continuous delivery of useful software.Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.Deliver working software frequently, with a preference for the shorter timescale.Collaboration between the business stakeholders and developers throughout the project.Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.Working software is the primary measure of progress.Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.Continuous attention to technical excellence and good design enhances agility.Simplicity – the art of maximizing the amount of work not done – is essential.The best architectures, requirements, and designs emerge from self-organizing teams.Agile Software Development PatternsAgile software development patterns are reusable solutions to common software development problems. The following are some typical agile software development patterns:The Single Responsibility Principle (SRP)The Open/Closed Principle (OCP)The Liskov Substitution Principle (LSP)The Dependency Inversion Principle (DIP)The Interface Segregation Principle (ISP)The Model-View-Controller (MVC) PatternThe Observer PatternThe Strategy PatternThe Factory Method PatternAgile Software Development PracticesAgile software development practices are a set ofactivities and techniques used in agile software development. The following are some typical agile software development practices:Iterative DevelopmentTest-Driven Development (TDD)Continuous IntegrationRefactoringPair ProgrammingAgile Software Development Benefits and ChallengesAgile software development has many benefits, including:Increased customer satisfactionIncreased qualityIncreased productivityIncreased flexibilityIncreased visibilityReduced riskAgile software development also has some challenges, including:Requires discipline and trainingRequires an experienced teamRequires good communicationRequires a supportive management cultureConclusionAgile software development is a set of values, principles, and practices for developing software. Agile software development is based on the Agile Manifesto, which represents the values and principles of the agile approach. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases. Agile software development has many benefits, including increased customer satisfaction, increased quality, increased productivity, increased flexibility, increased visibility, and reduced risk. Agile software development also has some challenges, including the requirement for discipline and training, the requirement for an experienced team, the requirement for good communication, and the requirement for a supportive management culture.。

英语原文Intelligent Traffic Light Controlby Marco Wiering The topic I picked for our community project was traffic lights. In a community, people need stop signs and traffic lights to slow down drivers from going too fast. If there were no traffic lights or stop signs, people’s lives would be in danger from drivers going too fast.The urban traffic trends towards the saturation, the rate of increase of the road of big city far lags behind rate of increase of the car.The urban passenger traffic has already become the main part of city traffic day by day and it has used about 80% of the area of road of center district. With the increase of population and industry activity, people's traffic is more and more frequent, which is unavoidable. What means of transportation people adopt produces pressure completely different to city traffic. According to calculating, if it is 1 to adopt the area of road that the public transport needs, bike needs 5-7, car needs 15-25, even to walk is 3 times more than to take public transits. So only by building road can't solve the city traffic problem finally yet. Every large city of the world increases the traffic policy to the first place of the question.For example，according to calculating, when the automobile owning amount of Shanghai reaches 800,000 (outside cars count separately ), if it distributes still as now for example: center district accounts for great proportion, even when several loop-lines and arterial highways have been built up , the traffic cannot be improved more than before and the situation might be even worse. So the traffic policy Shanghai must adopt , or called traffic strategy is that have priority to develop public passenger traffic of city, narrow the scope of using of the bicycle progressively , control the scale of growth of the car traffic in the center district, limit the development of the motorcycle strictly.There are more municipals project under construction in big city. the influence on the traffic is greater.Municipal infrastructure construction is originally a good thing of alleviating the traffic, but in the course of constructing, it unavoidably influence the local traffic. Some road sections are blocked, some change into an one-way lane, thus the vehicle can only take a devious route . The construction makes the road very narrow, forming the bottleneck, which seriously influence the car flow.When having stop signs and traffic lights, people have a tendency to drive slower andlook out for people walking in the middle of streets. To put a traffic light or a stop sign in a community, it takes a lot of work and planning from the community and the city to put one in. It is not cheap to do it either. The community first needs to take a petition around to everyone in the community and have them sign so they can take it to the board when the next city council meeting is. A couple residents will present it to the board, and they will decide weather or not to put it in or not. If not put in a lot of residents might be mad and bad things could happened to that part of the city.When the planning of putting traffic lights and stop signs, you should look at the subdivision plan and figure out where all the buildings and schools are for the protection of students walking and riding home from school. In our plan that we have made, we will need traffic lights next to the school, so people will look out for the students going home. We will need a stop sign next to the park incase kids run out in the street. This will help the protection of the kids having fun. Will need a traffic light separating the mall and the store. This will be the busiest part of the town with people going to the mall and the store. And finally there will need to be a stop sign at the end of the streets so people don’t drive too fast and get in a big accident. If this is down everyone will be safe driving, walking, or riding their bikes.In putting in a traffic light, it takes a lot of planning and money to complete it. A traffic light cost around $40,000 to $125,000 and sometimes more depending on the location. If a business goes in and a traffic light needs to go in, the business or businesses will have to pay some money to pay for it to make sure everyone is safe going from and to that business. Also if there is too many accidents in one particular place in a city, a traffic light will go in to safe people from getting a severe accident and ending their life and maybe someone else’s.The reason I picked this part of our community development report was that traffic is a very important part of a city. If not for traffic lights and stop signs, people’s lives would be in danger every time they walked out their doors. People will be driving extremely fast and people will be hit just trying to have fun with their friends. So having traffic lights and stop signs this will prevent all this from happening.Traffic in a city is very much affected by traffic light controllers. When waiting for a traffic light, the driver looses time and the car uses fuel. Hence, reducing waiting times before traffic lights can save our European society billions of Euros annually. To make traffic light controllers more intelligent, we exploit the emergence of novel technologies such as communication networks and sensor networks, as well as the use of more sophisticated algorithms for setting traffic lights. Intelligent traffic light control does not only mean thattraffic lights are set in order to minimize waiting times of road users, but also that road users receive information about how to drive through a city in order to minimize their waiting times. This means that we are coping with a complex multi-agent system, where communication and coordination play essential roles. Our research has led to a novel system in which traffic light controllers and the behaviour of car drivers are optimized using machine-learning methods.Our idea of setting a traffic light is as follows. Suppose there are a number of cars with their destination address standing before a crossing. All cars communicate to the traffic light their specific place in the queue and their destination address. Now the traffic light has to decide which option (ie, which lanes are to be put on green) is optimal to minimize the long-term average waiting time until all cars have arrived at their destination address. The learning traffic light controllers solve this problem by estimating how long it would take for a car to arrive at its destination address (for which the car may need to pass many different traffic lights) when currently the light would be put on green, and how long it would take if the light would be put on red. The difference between the waiting time for red and the waiting time for green is the gain for the car. Now the traffic light controllers set the lights in such a way to maximize the average gain of all cars standing before the crossing. To estimate the waiting times, we use 'reinforcement learning' which keeps track of the waiting times of individual cars and uses a smart way to compute the long term average waiting times using dynamic programming algorithms. One nice feature is that the system is very fair; it never lets one car wait for a very long time, since then its gain of setting its own light to green becomes very large, and the optimal decision of the traffic light will set his light to green. Furthermore, since we estimate waiting times before traffic lights until the destination of the road user has been reached, the road user can use this information to choose to which next traffic light to go, thereby improving its driving behaviour through a city. Note that we solve the traffic light control problem by using a distributed multi-agent system, where cooperation and coordination are done by communication, learning, and voting mechanisms. To allow for green waves during extremely busy situations, we combine our algorithm with a special bucket algorithm which propagates gains from one traffic light to the next one, inducing stronger voting on the next traffic controller option.We have implemented the 'Green Light District', a traffic simulator in Java in which infrastructures can be edited easily by using the mouse, and different levels of road usage can be simulated. A large number of fixed and learning traffic light controllers have already been tested in the simulator and the resulting average waiting times of cars have been plotted and compared. The results indicate that the learning controllers can reduce average waiting timeswith at least 10% in semi-busy traffic situations, and even much more when high congestion of the traffic occurs.We are currently studying the behaviour of the learning traffic light controllers on many different infrastructures in our simulator. We are also planning to cooperate with other institutes and companies in the Netherlands to apply our system to real world traffic situations. For this, modern technologies such as communicating networks can be brought to use on a very large scale, making the necessary communication between road users and traffic lights possible.中文翻译：智能交通信号灯控制马克·威宁我所选择的社区项目主题是交通灯。

毕业设计_外文文献翻译本科毕业设计外文文献翻译（题目：packethandlinghardwaresupport学生姓名：学院：系别：专业：班级：指导教师：二〇一四年六月packethandlinghardwaresupport参考文献：texasinstruments1101low-powersub-1ghzrftransceiver.ti.2013 the1101hasbuilt-inhardwaresupportforpacketorientedradioprotocols.intransmitmode,thepackethandlercanbeconfiguredtoaddth efollowingelementstothepacketstoredinthetxfifo:aprogrammablenumberofpreamblebytesatwobytesynchronization(sync)word.canbeduplicatedtogivea4-b ytesyncword(remended).itisnotpossibletoonlyinsertpreambleoronl yinsertasyncwordacrcchecksumputedoverthedatafield.theremendedsettingis4-bytepreambleand4-bytesyncword,exceptf or500kbauddataratewheretheremendedpreamblelengthis8bytes.in addition,thefollowingcanbeimplementedonthedatafieldandtheop tional2-bytecrcchecksum:whiteningofthedatawithapn9sequenceforwarderrorcorrection(fec)bytheuseofinterleavingandcodingo fthedata(convolutionalcoding)inreceivemode,thepackethandlingsupportwillde-constructtheda tapacketbyimplementingthefollowing(ifenabled):preambledetectionsyncworddetectioncrcputationandcrccheckonebyteaddresscheckpacketlengthcheck(lengthbytecheckedagainstaprogrammablemaxi mumlength)de-whiteningde-interleavinganddecodingoptionally,twostatusbytes(seetable27andtable28)withrssivalu e,linkqualityindication,andcrcstatuscanbeappendedintherxfif o.1.datawhiteningfromaradioperspective,theidealovertheairdataarerandomanddcf ree.thisresultsinthesmoothestpowerdistributionovertheoupied bandwidth.thisalsogivestheregulationloopsinthereceiverunifo rmoperationconditions(ondatadependencies).realdataoftencontainlongsequencesofzerosandones.inthesecase s,performancecanbeimprovedbywhiteningthedatabeforetransmitting,andde-whiteningthedatainthereceiver.with1101,thiscanbedoneautomatically.bysettingpktctrlo.white _data=1,alldata,exceptthepreambleandthesyncwordwillbexor-ed witha9-bitpseudo-random(pn9)sequencebeforebeingtransmitted. thisisshowninfigure16.atthereceiverend,thedataarexor-edwith thesamepseudorandomsequence.inthisway,thewhiteningisreverse d,andtheoriginaldataappearinthereceiver.thepn9sequenceisini tializedtoall1’s.2.packetformattheformatofthedatapacketcanbeconfiguredandconsistsofthefoll owingitems(seefigure17):preamblesynchronizationwordoptionallengthbyteoptionaladdressbytepayloadoptional2bytecrcthepreamblepatternisanalternatingsequenceof onesandzeros(10101010…).theminimumlengthofthepreambleispro grammablethroughthevalueofmdmcfg1.num_preamble.whenenabling tx,themodulatorwillstarttransmittingthepreamble.whentheprog rammednumberofpreamblebyteshasbeentransmitted,themodulatorwillsendthesyncwordandthendatafromt hetxfifoifdataisavailable.ifthetxfifoisempty,themodulatorwi llcontinuerosendpreamblebytesuntilthefirstbyteiswrittentoth etxfifo.themodulatorwillthensendthesyncwordandthenthedataby tes.thesynchronizationwordisatwo-bytevaluesetinthesync1andsync0 registers.thesyncwordprovidesbytesynchronizationoftheiningp acket.aone-bytesyncwordcanbeemulatedbysettingtheaync1valuet othepreamblepattern.itisalsopossibletoemulatea32bitsyncword bysettingmdmcfg2.sync_modeto3or7.thesyncwordwillthenberepea tedtwice.1101supportsbothconstantpacketlengthprotocolsandvariablelen gthprotocols.variableorfixedpacketlengthmodecanbeusedforpac ketsupto255bytes.forlongerpackets,infinitepacketlengthmodem ustbeused.fixedpacketlengthmodeisselectedbysettingpktctrl0.length_con fig=0.thedesiredpacketlengthissetbythepktlenregister.thisvaluemustbedifferentfrom0.invariablepacketlengthmode,pktctrl0.length_config=1,thepack etlengthisconfiguredbythefirstbyteafterthesyncword.thepacke tlengthisdefinedasthepayloaddata,excludingthelengthbyteando ptionalcrc.thepktlenregisterisusedtosetthemaximumpacketleng thallowedinrx.anypacketreceivedwithalengthbytewithavaluegre aterthanpktlenwillbediscarded.thepktlenvaluemustbedifferent from0.thebytewrittentothetxfifomustbedifferentfrom0.withpktctrl0.length_config=2,thepacketlengthissettoinfinite andtransmissionandreceptionwillcontinueuntilturnedoffmanual ly.asdescribedinthenextsection,thiscanbeusedtosupportpacket formatswithdifferentlengthconfigurationthannativelysupporte dby1101.oneshouldmakesurethattxisnotturnoffduringthetransmissionofthefirsthalfofanybyte.refertothe11012.1arbitrarylengthfieldconfigurationthepacketlengthregister,pktlen,canbereprogrammedduringrecei veandtransmit.inbinationwithfixedpacketlengthmode(pktctrl0. length_config=0),thisopensthepossibilitytohaveadifferentlen gthfieldconfigurationcansupportedforvariablelengthpackets(i nvariablepacketlengthmodethelengthbyteisthefirstbyteafterth esyncword).atthestartofreception,thepacketlengthissetalarge value.themcureadsoutenoughbytestointerpretthelengthfieldint hepacket.thenthepktlenvalueissetaordingtothisvalue.theendof packetwillourwhenthebytecounterinthepackethandlerisequaltot hepktlenregister.thus,themcumustbeabletoprogramthecorrectle ngth,beforetheinternalcounterreachesthepacketlength.2.2packetlength>255thepacketautomationcontrolregister,pktctrl0,canbereprogramm edduringtxandrx.thisopensthepossibilitytotransmitandreceive packetsthatarelongerthan256bytesandstillbeabletousethepacke thandlinghardwaresupport.atthestartofthepacket,theinfinitep acketlengthmode(pktctrl0.length_config=2)mustbeactive.onthe txside,thepktlenregisterissettomod(length,256).ontherxsidet hemcureadsoutenoughbytestointerpretthelengthfieldinthepacke tandsetsthepktlenregistertomod(length,256).whenlessthan256b ytesremainsofthepacket,themcudisablesinfinitepacketlengthmo deandactivatesfixedpacketlengthmode.whentheinternalbytecoun terreachesthepktlenvalue,thetransmissionorreceptionends(the radioentersthestatedeterminedbytxoff_modeorrxoff_mode).auto maticcrcappending/checkingcanalsobeused(bysettingpktctrl0.c rc_en=1).whenforexamplea600-bytepacketistobetransmitted,themcushould dothefollowing(seealsofigure18)setpktctrl0.length_config=2.pre-programthepktlenregistertomod(600,256)=88.transmitatleast345bytes(600-255),forexamplebyfillingthe64-b ytetxfifosixtimes(384bytestransmitted).setpktctrl0.length_config=0.thetransmissionendswhenthepacketcounterreaches88.atotalof60 0bytesaretransmitted.3packetfilteringinreceivemode1101supportsthreedifferenttypesofpacket-filtering;addressfi ltering,maximumlengthfiltering,andcrcfiltering.3.1addressingfilteringsettingpktctrl1.adr_chktoanyothervaluethanzeroenablesthepac ketaddressfilter.thepackethandlerenginewillparethedestinati onaddressbyteinthepacketwiththeprogrammednodeaddressinthead drregisterandthe0*00broadcastaddresswhenpktctrl1.adr_chk=10 orboththe0*00and0*ffbroadcastaddresseswhenpktctrl1.adr_chk= 11.ifthereceivedaddressmatchesavalidaddress,thepacketisrece ivedandwrittenintotherxfifo.iftheaddressmatchfails,thepacke tisdiscardedandreceivemoderestarted(regardlessofthemcsm1.rx off_modesetting).ifthereceivedaddressmatchesavalidaddresswhenusinginfinitepacketlengthmodeandaddressfilteringisenabled,0*ffwillbewritte nintotherxfifofollowedbytheaddressbyteandthenthepayloaddata.3.2maximumlengthfilteringinvariablepacketlengthmode,pktctrl0.length_config=1,thepktl en.packet_lengthregistervalueisusedtosetthemaximumallowedpa cketlength.ifthereceivedlengthbytehasalargervaluethanthis,t hepacketisdiscardedandreceivemoderestarted(regardlessofthem csm1.rxoff_modesetting).3.3crcfilteringthefilteringofapacketwhencrccheckfailsisenabledbysettingpkt ctrl1.crc_autoflush=1.thecrcautoflushfunctionwillflushtheen tirerxfifoifthecrccheckfails.afterautoflushingtherxfifo,the nextstatedependsonthemcsm1.rxoff_modesetting.whenusingtheautoflushfunction,themaximumpacketlengthis63byt esinvariablepacketlengthmode.notethatwhenpktctrl1append_sta tusisenabled,themaximumallowedpacketlengthisreducedbytwobyt esinordertomakeroomintherxfifoforthetwostatusbytesappendeda ttheendofthepacket.sincetheentirerxfifoisflushedwhenthecrcc heckfails,thepreviouslyreceivedpacketmustbereadoutofthefifo beforereceivingthecurrentpacket.themcumustnotreadfromthecur rentpacketuntilthecrchasbeencheckedasok.4packethandlingintr ansmitmodethepayloadthatistobetransmittedmustbewrittenintothetxfifo.t hefirstbytewrittenmustbethelengthbytewhenvariablepacketleng thisenabled.thelengthbytehasavalueequaltothepayloadofthepac ket(includingtheoptionaladdressbyte).ifaddressrecognitionisenabledonthereceiver,thesecondbytewrittentothetxfifomustbet headdressbyte.iffixedpacketlengthisenabled,thefirstbytewrittentothetxfifo shouldbetheaddress(assumingthereceiverusesaddressrecognitio n).themodulatorwillfirstsendtheprogrammednumberofpreamblebytes .ifdataisavaibleinthetxfifo,themodulatorwillsendthetwo-byte s(optionally4-byte)syncwordfollowedbythepayloadinthetxfifo.ifcrcisenabled,thec hecksumiscalculatedoverallthedatapulledfromthetxfifo,andthe resultissentastwoextrabytesfollowingthepayloaddata.ifthetxf iforunsemptybeforethepletepackethasbeentransmitted,theradiowillentertxfifo_underflowstate.theonlywaytoexitthisstateisb yissuingansftxstrobe.writingtothetxfifoafterithasbeenunderf lowedwillnotrestarttxmode.ifwhiteningisenabled,everythingfollowingthesyncwordswillbew hitened.thisisdonebeforetheoptionalfec/interleaverstage.whi teningisenabledbysettingpktctrl0.white_data=1.iffec/interleavingisenabled,everythingfollowingthesyncwords willbescrambledbytheinterleaverandfecencodedbeforebeingmodu lated.fecisenabledbysettingmdmcfg1.fec_en=1.5packethandlinginreceivemodeinreceivemode,thedemodulatorandpackethandlerwillsearchforav alidpreambleandthesyncword.whenfound,thesynchronismandwillreceivethefirstpayloadbyte.iffec/interleavingisenabled,thefecdecoderwillstarttodecodet hefirstpayloadbyte.theintrerleaverwillde-scramblethebitsbef oreanyotherprocessingisdonetothedata.ifwhiteningisenabled,thedatawillbede-whitenedatthisstage.whenvariablepacketlengthmodeisenabled,thefirstbyteistheleng thbyte.thepackethandlerstoresthisvalueasthepacketlengthandr eceivesthenumberofbytesindicatedbythelengthbyte.iffixedpack etlengthmodeisused,thepackethandlerwillaepttheprogrammednum berofbytes.next,thepackethandleroptionallycheckstheaddressandonlycontinuesthereceptioniftheaddressmatches.ifautomaticcrccheckisen abled,thepackethandlerputescrcandmatchesitwiththeappendedcr cchecksum.attheendofthepayload,thepackethandlerwilloptionallywhitetwo extrapacketstatusbytes(seetable27andtable28)thatcontaincrcs tatus,linkqualityindication,andrssivalue.6packethandlinginfirmwarewhenimplementingapacketorientedradioprotocolinfirmware,them cuneedstoknowwhenapackethasbeenreceived/transmitted.additio nally,forpacketslongerthan64bytes,therxfifoneedstoberefille dwhiteintx.thismeansthatthemcuneedstoknowthenumberofbytesth atcanbereadfromorwrittentotherxfifoandtxfiforespectively.th erearetwopossiblesolutionstogetthenecessarystatusinformation:a)interruptdrivensolutionthegdopinscanbeusedinbothrxandtxtogiveaninterruptwhenasyncw ordhasbeenreceived/transmittedorwhenapletepackethasbeenrece ived/transmittedbysettingiofgx.gdox_cfg=0*06.inaddition,the rearetwoconfigurationsfortheiocfgx.gdox_cfgregisterthatcanb eusedasaninterruptsourcetoprovideinformationonhowmanybytest hatareintherxfifoandtxfiforespectively.theiocfgx.gdox_cfg=0 *02andiocfgx.gdox_cfg=0*03configurationsareassociatedwithth etxfifo.seetable41formoreinformation.b)spipollingthepktststusregistercanbepolledatagivenratetogetinformation aboutthecurrentgdo2andgdo0valuesrespectively.therxbytesandtxbytesregisterscanbepolledatagivenratetogetinformationabout thenumberofbytesintherxfifoandtxfiforespectively.alternativ ely,thenumberofbytesintherxfifoandthetxfifocanbereadfromthe chipstatusbytereturnedonthemisolineeachtimeaheaderbyte,data byte,ormandstrobeissentonthespibus.itisremendedtoemployaninterruptdrivensolutionsincehighrates pipollingreducestherxsensitivity.furthermore,asexplainedins ection10.3andthe1101erratanotes[4],whenusingspipolling,ther eisasmall,butfinite,probabilitythatasinglereadfromregisters pkstatus,rxbytesandtxbytesisbeingcorrupt.thesameisthecasewh enreadingthechipstatusbyte.refertothetiwebsiteforswexamples([9]and[10]).数据包处理的硬件支持1101提供了对数据包导向无线协议的内置硬件支持。

Technology change and environmental management for cement manufacturing and Industrial pollution control in PeruAbstract:This article mainly introduced some research results made by USA In the cement industry pollution control, and in Peru, for example, analyzed the important influence that cement industrial pollution for a government.key words :pollution control cement industry industry pollutionenvironmental managementHistorically, the cement industry has been challenged with the requirement of improving its manufacturing process while reducing its footprint on the environment. At the same time, global competition poses more challenges to improving the bottom line of the business. Research and development of pollution abatement technology for cement manufacturing is key for effectively operating in this new environment. These new technological advancements compete against established technologies when cement manufacturers evaluate different pollution prevention strategies.;This research developed a quantitative tool to benchmark various technologies available to produce Portland cement in the United States. The model "Technology Change Evaluation for the Cement Industry" (TCECI) was developed to achieve this goal considering a full cost approach. Several production scenarios were designed and evaluated to represent the current and potential future conditions of the cement industry in the United States. The decision making process to select the Best Available Technology (BAT) for cement manufacturing in the United States considered the minimization of the private and the total cost (i.e., including private and social costs) under different multi-pollutant approaches. One of these approaches considered the minimization of carbon dioxide emissions from the calcination of raw materials and the combustion of the fuel from cement manufacturing. These emissions were estimated for each production scenario considering an emission tax scheme and an emission allowance trading program.;The most relevant result obtained from this research is the integration of environmental and social aspects of cement making into the currentdecision making process for technology change. This integration led to production alternatives with improved environmental, social and economic performance. Additionally, the results of this research indicate that the current technology mix for cement manufacturing in the United States limits the feasibility of new cement plants when considering the full cost approach. However, the results of the analysis indicate that the implementation of BAT in existing plants (under the conditions and characteristics assumed by the TCECI model) improves their overall economic and environmental performance. The reduction estimated for the full cost ranged from 19% to 22% while comparing the baseline scenario for the year 2004 with a multipollutant approach (i.e., in 2004 dollars per ton of clinker, $50 -production scenario No. 8- and $48 -production scenario No. 7- versus $61 from the baseline scenario).;Finally, the results also indicate that within the limited sample of production scenarios considered there is large variability in the estimated uncertainty of the costs associated with the production of cement, the air emissions reported from the production process and the performance data from available technologies for pollution control and process optimization. The differences of the social costs estimated for each production scenario were found statistically more significant when considering the effect of the use of alternative fuels (i.e., tire fuel instead of coal) than the effect of a more stringent regulatory environment.;Since performance data for control technologies and air emissions are becoming more important to private and public policy decision making, it is recommended that the Environmental Protection Agency and the cement industry treat uncertainty explicitly, by means of adopting standardized measurement and reporting methodologies for air emissions among other relevant measures.The absence of reliable and comprehensive systems of monitoring industrial pollution has been an obstacle for better environmental management in developing countries. Peru is not an exception. While there is some progress in environmental protection, industrial pollution control is lagging behind. This research assesses priorities in industrial pollution control in Peru, identifies sectors deserving most attention by the policy-maker to better allocate scarce resources, and proposes cost-effective industrial pollution policies.;Priority sectors are identified based on their contribution to total industrial pollution. This is achieved by applying the World Bank's Industrial Pollution Projection System (IPPS) with original firm-level data from the Peruvian Ministry of Industry. Among the priority sectors, which are essentially the same for Lima and Callao and the Provinces, two are selected: cementand chemicals.;To estimate an industrial pollution baseline in Peru is virtually impossible due to the absence of monitoring. This research uses unpublished results from the only scientific survey of effluents and emissions for Peruvian industries (1997) to estimate a baseline for the cement and chemicals sectors. The difference between the targets and the observed levels of pollution is significant, but concentrated on key pollutants. Three policies are proposed for priority sectors and key pollutants: (1) current standards for the cement sector; (2) modified standards for the cement sector and new standards for the chemicals sector; and (3) a combination of standards and pollution charges. These policies were evaluated using a cost-savings framework, estimating potential savings of applying market-based instruments vs. command and control mechanisms. Sectoral abatement costs are calculated using World Bank estimates and Peruvian plant-level data from the Ministry of Industry. The policy that includes a market-based instrument is considered the least-cost option for both sectors.;Empirically, this research provides projected industrial pollution intensities and sectoral pollution data for Peru, which will aid future research. In addition to providing unique data on industrial abatement costs, it calculates cost-savings for market-based instruments vs. command and control mechanisms. This dissertation also identifies opportunities for future industrial pollution control in Peru.美国水泥工业生产中技术的改变和环境管理以及秘鲁水泥生产中污染的控制摘要：本文主要介绍了美国在水泥工业污染控制方面所取得的一些研究成果，并以秘鲁为例，分析了水泥工业污染对一个政府的重要影响。

毕业设计外文翻译评分标准优秀：外文资料内容与本人毕业设计（论文）内容相关性好，有明显的参考价值；翻译汉字达3000字以上；没有重要误译，忠实原文，准确传达原文内容；遵循翻译的基本原则，能灵活处理一般性翻译技巧和具体句型翻译的关系、概念的直译与意译之间的关系；没有基本的语法错误，用词准确；译文通顺，符合汉语表达习惯；良好：外文资料内容与本人毕业设计（论文）内容相关性较好，有较好的参考价值；翻译汉字达3000字以上；没有重要误译，忠实原文，较准确传达原文内容；遵循翻译的基本原则，能处理一般性翻译技巧和具体句型翻译的关系、概念的直译与意译之间的关系；很少的语法错误，用词较准确；译文较通顺，符合汉语表达习惯；中：外文资料内容与本人毕业设计（论文）内容相关性一般，有一定的参考价值；翻译汉字达3000字以上；没有大的误译，基本忠实原文，基本传达原文内容；遵循翻译的基本原则，能处理一般性翻译技巧和具体句型翻译的关系、概念的直译与意译之间的关系；没有多的语法错误，用词较合理；译文通顺，符合汉语表达习惯；及格：外文资料内容与本人毕业设计（论文）内容相关性一般，参考价值一般；翻译汉字达3000字以上；没有大的误译，基本忠实原文，基本传达原文内容；遵循翻译的基本原则，能适当处理一般性翻译技巧和具体句型翻译的关系、概念的直译与意译之间的关系；语法错误较多，用词较欠合理；译文基本通顺，基本符合汉语表达习惯；不及格：外文资料内容与本人毕业设计（论文）内容相关性差，无参考价值；翻译汉字达不到3000字；存在大的误译，没能忠实原文，不能传达原文内容；语法错误很多，用词较不合理；译文不通顺，大部分不符合汉语表达习惯；多路红外遥控开关的设计课题简介多路遥控开关，有一个遥控接收板，遥控接收板连接多个单通道开关电路，其特征在于单通道开关电路由与门电路、射极跟随器、双稳态电路、继电器电路和电源电路组成。

一种多路遥控开关，包括一个遥控接收板，遥控接收板连接多个单通道开关电路，其特征在于单通道开关电路由与门电路、射极跟随器、双稳态电路、继电器驱动电路和电源电路组成。

本科毕业设计（论文）外文翻译译文学生姓名：院（系）：油气资源学院专业班级：物探0502指导教师：完成日期：年月日地震驱动评价与发展：以玻利维亚冲积盆地的研究为例起止页码：1099——1108出版日期：NOVEMBER 2005THE LEADING EDGE出版单位：PanYAmericanYEnergyvBuenosYAiresvYArgentinaJPYBLANGYvYBPYExplorationvYHoustonvYUSAJ.C.YCORDOVAandYE.YMARTINEZvYChacoYS.A.vYSantaYCruzvYBolivia 通过整合多种地球物理地质技术，在玻利维亚冲积盆地，我们可以减少许多与白垩纪储集层勘探有关的地质技术风险。

通过对这些远景区进行成功钻探我们可以验证我们的解释。

这些方法包括盆地模拟，联井及地震叠前同时反演，岩石性质及地震属性解释，A VO/A V A,水平地震同相轴，光谱分解。

联合解释能够得到构造和沉积模式的微笑校正。

迄今为止，在新区有七口井已经进行了成功钻探。

基质和区域地质。

Tarija/Chaco盆地的subandean 褶皱和冲断带山麓的中部和南部，部分扩展到玻利维亚的Boomerange地区经历了集中的成功的开采。

许多深大的泥盆纪气田已经被发现，目前正在生产。

另外在山麓发现的规模较小较浅的天然气和凝析气田和大的油田进行价格竞争，如果他们能产出较快的油流而且成本低。

最近发现气田就是这种情况。

接下来，我们赋予Aguja的虚假名字就是为了讲述这些油田的成功例子。

图1 Aguja油田位于玻利维亚中部Chaco盆地的西北角。

基底构造图显示了Isarzama背斜的相对位置。

地层柱状图显示了主要的储集层和源岩。

该油田在Trija和冲积盆地附近的益背斜基底上，该背斜将油田和Ben i盆地分开（图1），圈闭类型是上盘背斜，它存在于连续冲断层上，Aguja有两个主要结构：Aguja中部和Aguja Norte,通过重要的转换压缩断层将较早开发的“Sur”油田分开Yantata Centro结构是一个三路闭合对低角度逆冲断层并伴随有小的摆幅。

编号：毕业设计(论文)外文翻译（原文）院（系）：桂林电子科技大学专业：电子信息工程学生姓名： xx学号： xxxxxxxxxxxxx 指导教师单位：桂林电子科技大学姓名： xxxx职称： xx2014年x月xx日Timing on and off power supplyusesThe switching power supply products are widely used in industrial automation and control, military equipment, scientific equipment, LED lighting, industrial equipment,communications equipment,electrical equipment,instrumentation, medical equipment, semiconductor cooling and heating, air purifiers, electronic refrigerator, LCD monitor, LED lighting, communications equipment, audio-visual products, security, computer chassis, digital products and equipment and other fields.IntroductionWith the rapid development of power electronics technology, power electronics equipment and people's work, the relationship of life become increasingly close, and electronic equipment without reliable power, into the 1980s, computer power and the full realization of the switching power supply, the first to complete the computer Power new generation to enter the switching power supply in the 1990s have entered into a variety of electronic, electrical devices, program-controlled switchboards, communications, electronic testing equipment power control equipment, power supply, etc. have been widely used in switching power supply, but also to promote the rapid development of the switching power supply technology .Switching power supply is the use of modern power electronics technology to control the ratio of the switching transistor to turn on and off to maintain a stable output voltage power supply, switching power supply is generally controlled by pulse width modulation (PWM) ICs and switching devices (MOSFET, BJT) composition. Switching power supply and linear power compared to both the cost and growth with the increase of output power, but the two different growth rates. A power point, linear power supply costs, but higher than the switching power supply. With the development of power electronics technology and innovation, making the switching power supply technology to continue to innovate, the turning points of this cost is increasingly move to the low output power side, the switching power supply provides a broad space for development.The direction of its development is the high-frequency switching power supply, high frequency switching power supply miniaturization, and switching power supply into a wider range of application areas, especially in high-tech fields, and promote the miniaturization of high-tech products, light of. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.classificationModern switching power supply, there are two: one is the DC switching power supply; the other is the AC switching power supply. Introduces only DC switching power supply and its function is poor power quality of the original eco-power (coarse) - such as mains power or battery power, converted to meet the equipment requirements of high-quality DC voltage (Varitronix) . The core of the DC switching power supply DC / DC converter. DC switching power supply classification is dependent on the classification of DC / DC converter. In other words, the classification of the classification of the DC switching power supply and DC/DC converter is the classification of essentially the same, the DC / DC converter is basically a classification of the DC switching power supply.DC /DC converter between the input and output electrical isolation can be divided into two categories: one is isolated called isolated DC/DC converter; the other is not isolated as non-isolated DC / DC converter.Isolated DC / DC converter can also be classified by the number of active power devices. The single tube of DC / DC converter Forward (Forward), Feedback (Feedback) two. The double-barreled double-barreled DC/ DC converter Forward (Double Transistor Forward Converter), twin-tube feedback (Double Transistor Feedback Converter), Push-Pull (Push the Pull Converter) and half-bridge (Half-Bridge Converter) four. Four DC / DC converter is the full-bridge DC / DC converter (Full-Bridge Converter).Non-isolated DC / DC converter, according to the number of active power devices can be divided into single-tube, double pipe, and four three categories. Single tube to a total of six of the DC / DC converter, step-down (Buck) DC / DC converter, step-up (Boost) DC / DC converters, DC / DC converter, boost buck (Buck Boost) device of Cuk the DC / DC converter, the Zeta DC / DC converter and SEPIC, the DC / DC converter. DC / DC converters, the Buck and Boost type DC / DC converter is the basic buck-boost of Cuk, Zeta, SEPIC, type DC / DC converter is derived from a single tube in this six. The twin-tube cascaded double-barreled boost (buck-boost) DC / DC converter DC / DC converter. Four DC / DC converter is used, the full-bridge DC / DC converter (Full-Bridge Converter).Isolated DC / DC converter input and output electrical isolation is usually transformer to achieve the function of the transformer has a transformer, so conducive to the expansion of the converter output range of applications, but also easy to achieve different voltage output , or a variety of the same voltage output.Power switch voltage and current rating, the converter's output power is usually proportional to the number of switch. The more the number of switch, the greater the output power of the DC / DC converter, four type than the two output power is twice as large,single-tube output power of only four 1/4.A combination of non-isolated converters and isolated converters can be a single converter does not have their own characteristics. Energy transmission points, one-way transmission and two-way transmission of two DC / DC converter. DC / DC converter with bi-directional transmission function, either side of the transmission power from the power of lateral load power from the load-lateral side of the transmission power.DC / DC converter can be divided into self-excited and separately controlled. With the positive feedback signal converter to switch to self-sustaining periodic switching converter, called self-excited converter, such as the the Luo Yeer (Royer,) converter is a typical push-pull self-oscillating converter. Controlled DC / DC converter switching device control signal is generated by specialized external control circuit.the switching power supply.People in the field of switching power supply technology side of the development of power electronic devices, while the development of the switching inverter technology, the two promote each other to promote the switching power supply annual growth rate of more than two digits toward the light, small, thin, low-noise, high reliability, the direction of development of anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, AC / AC DC / AC, such as inverters, DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardization, and has been recognized by the user, but AC / DC modular, its own characteristics make the modular process, encounter more complex technology and manufacturing process. Hereinafter to illustrate the structure and characteristics of the two types of switching power supply.Self-excited: no external signal source can be self-oscillation, completely self-excited to see it as feedback oscillation circuit of a transformer.Separate excitation: entirely dependent on external sustain oscillations, excited used widely in practical applications. According to the excitation signal structure classification; can be divided into pulse-width-modulated and pulse amplitude modulated two pulse width modulated control the width of the signal is frequency, pulse amplitude modulation control signal amplitude between the same effect are the oscillation frequency to maintain within a certain range to achieve the effect of voltage stability. The winding of the transformer can generally be divided into three types, one group is involved in the oscillation of the primary winding, a group of sustained oscillations in the feedback winding, there is a group of load winding. Such as Shanghai is used in household appliances art technological production of switching power supply, 220V AC bridge rectifier, changing to about 300V DC filter added tothe collector of the switch into the transformer for high frequency oscillation, the feedback winding feedback to the base to maintain the circuit oscillating load winding induction signal, the DC voltage by the rectifier, filter, regulator to provide power to the load. Load winding to provide power at the same time, take up the ability to voltage stability, the principle is the voltage output circuit connected to a voltage sampling device to monitor the output voltage changes, and timely feedback to the oscillator circuit to adjust the oscillation frequency, so as to achieve stable voltage purposes, in order to avoid the interference of the circuit, the feedback voltage back to the oscillator circuit with optocoupler isolation.technology developmentsThe high-frequency switching power supply is the direction of its development, high-frequency switching power supply miniaturization, and switching power supply into the broader field of application, especially in high-tech fields, and promote the development and advancement of the switching power supply, an annual more than two-digit growth rate toward the light, small, thin, low noise, high reliability, the direction of the anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, the DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardized, and has been recognized by the user, but modular AC / DC, because of its own characteristics makes the modular process, encounter more complex technology and manufacturing process. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.The switching power supply applications in power electronic devices as diodes, IGBT and MOSFET.SCR switching power supply input rectifier circuit and soft start circuit, a small amount of applications, the GTR drive difficult, low switching frequency, gradually replace the IGBT and MOSFET.Direction of development of the switching power supply is a high-frequency, high reliability, low power, low noise, jamming and modular. Small, thin, and the key technology is the high frequency switching power supply light, so foreign major switching power supply manufacturers have committed to synchronize the development of new intelligent components, in particular, is to improve the secondary rectifier loss, and the power of iron Oxygen materials to increase scientific and technological innovation in order to improve the magnetic properties of high frequency and large magnetic flux density (Bs), and capacitor miniaturization is a key technology. SMT technology allows the switching power supply has made considerable progress, the arrangement of the components in the circuit board on bothsides, to ensure that the light of the switching power supply, a small, thin. High-frequency switching power supply is bound to the traditional PWM switching technology innovation, realization of ZVS, ZCS soft-switching technology has become the mainstream technology of the switching power supply, and a substantial increase in the efficiency of the switching power supply. Indicators for high reliability, switching power supply manufacturers in the United States by reducing the operating current, reducing the junction temperature and other measures to reduce the stress of the device, greatly improve the reliability of products.Modularity is the overall trend of switching power supply, distributed power systems can be composed of modular power supply, can be designed to N +1 redundant power system, and the parallel capacity expansion. For this shortcoming of the switching power supply running noise, separate the pursuit of high frequency noise will also increase, while the use of part of the resonant converter circuit technology to achieve high frequency, in theory, but also reduce noise, but some The practical application of the resonant converter technology, there are still technical problems, it is still a lot of work in this field, so that the technology to be practical.Power electronics technology innovation, switching power supply industry has broad prospects for development. To accelerate the pace of development of the switching power supply industry in China, it must take the road of technological innovation, out of joint production and research development path with Chinese characteristics and contribute to the rapid development of China's national economy.Developments and trends of the switching power supply1955 U.S. Royer (Roger) invented the self-oscillating push-pull transistor single-transformer DC-DC converter is the beginning of the high-frequency conversion control circuit 1957 check race Jen, Sen, invented a self-oscillating push-pull dual transformers, 1964, U.S. scientists canceled frequency transformer in series the idea of switching power supply, the power supply to the size and weight of the decline in a fundamental way. 1969 increased due to the pressure of the high-power silicon transistor, diode reverse recovery time shortened and other components to improve, and finally made a 25-kHz switching power supply.At present, the switching power supply to the small, lightweight and high efficiency characteristics are widely used in a variety of computer-oriented terminal equipment, communications equipment, etc. Almost all electronic equipment is indispensable for a rapid development of today's electronic information industry power mode. Bipolar transistor made of 100kHz, 500kHz power MOS-FET made, though already the practical switching power supply is currently available on the market, but its frequency to be further improved. Toimprove the switching frequency, it is necessary to reduce the switching losses, and to reduce the switching losses, the need for high-speed switch components. However, the switching speed will be affected by the distribution of the charge stored in the inductance and capacitance, or diode circuit to produce a surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Which, in order to prevent the switching Kai - closed the voltage surge, RC or LC buffers can be used, and the current surge can be caused by the diode stored charge of amorphous and other core made of magnetic buffer . However, the high frequency more than 1MHz, the resonant circuit to make the switch on the voltage or current through the switch was a sine wave, which can reduce switching losses, but also to control the occurrence of surges. This switch is called the resonant switch. Of this switching power supply is active, you can, in theory, because in this way do not need to greatly improve the switching speed of the switching losses reduced to zero, and the noise is expected to become one of the high-frequency switching power supply The main ways. At present, many countries in the world are committed to several trillion Hz converter utility.the principle of IntroductionThe switching power supply of the process is quite easy to understand, linear power supplies, power transistors operating in the linear mode and linear power, the PWM switching power supply to the power transistor turns on and off state, in both states, on the power transistor V - security product is very small (conduction, low voltage, large current; shutdown, voltage, current) V oltammetric product / power device is power semiconductor devices on the loss.Compared with the linear power supply, the PWM switching power supply more efficient process is achieved by "chopping", that is cut into the amplitude of the input DC voltage equal to the input voltage amplitude of the pulse voltage. The pulse duty cycle is adjusted by the switching power supply controller. Once the input voltage is cut into the AC square wave, its amplitude through the transformer to raise or lower. Number of groups of output voltage can be increased by increasing the number of primary and secondary windings of the transformer. After the last AC waveform after the rectifier filter the DC output voltage.The main purpose of the controller is to maintain the stability of the output voltage, the course of their work is very similar to the linear form of the controller. That is the function blocks of the controller, the voltage reference and error amplifier can be designed the same as the linear regulator. Their difference lies in the error amplifier output (error voltage) in the drive before the power tube to go through a voltage / pulse-width conversion unit.Switching power supply There are two main ways of working: Forward transformand boost transformation. Although they are all part of the layout difference is small, but the course of their work vary greatly, have advantages in specific applications.the circuit schematicThe so-called switching power supply, as the name implies, is a door, a door power through a closed power to stop by, then what is the door, the switching power supply using SCR, some switch, these two component performance is similar, are relying on the base switch control pole (SCR), coupled with the pulse signal to complete the on and off, the pulse signal is half attentive to control the pole voltage increases, the switch or transistor conduction, the filter output voltage of 300V, 220V rectifier conduction, transmitted through the switching transformer secondary through the transformer to the voltage increase or decrease for each circuit work. Oscillation pulse of negative semi-attentive to the power regulator, base, or SCR control voltage lower than the original set voltage power regulator cut-off, 300V power is off, switch the transformer secondary no voltage, then each circuit The required operating voltage, depends on this secondary road rectifier filter capacitor discharge to maintain. Repeat the process until the next pulse cycle is a half weeks when the signal arrival. This switch transformer is called the high-frequency transformer, because the operating frequency is higher than the 50HZ low frequency. Then promote the pulse of the switch or SCR, which requires the oscillator circuit, we know, the transistor has a characteristic, is the base-emitter voltage is 0.65-0.7V is the zoom state, 0.7V These are the saturated hydraulic conductivity state-0.1V-0.3V in the oscillatory state, then the operating point after a good tune, to rely on the deep negative feedback to generate a negative pressure, so that the oscillating tube onset, the frequency of the oscillating tube capacitor charging and discharging of the length of time from the base to determine the oscillation frequency of the output pulse amplitude, and vice versa on the small, which determines the size of the output voltage of the power regulator. Transformer secondary output voltage regulator, usually switching transformer, single around a set of coils, the voltage at its upper end, as the reference voltage after the rectifier filter, then through the optocoupler, this benchmark voltage return to the base of the oscillating tube pole to adjust the level of the oscillation frequency, if the transformer secondary voltage is increased, the sampling coil output voltage increases, the positive feedback voltage obtained through the optocoupler is also increased, this voltage is applied oscillating tube base, so that oscillation frequency is reduced, played a stable secondary output voltage stability, too small do not have to go into detail, nor it is necessary to understand the fine, such a high-power voltage transformer by switching transmission, separated and after the class returned by sampling the voltage from the opto-coupler pass separated after class, so before the mains voltage, and after the classseparation, which is called cold plate, it is safe, transformers before power is independent, which is called switching power supply.the DC / DC conversionDC / DC converter is a fixed DC voltage transformation into a variable DC voltage, also known as the DC chopper. There are two ways of working chopper, one Ts constant pulse width modulation mode, change the ton (General), the second is the frequency modulation, the same ton to change the Ts, (easy to produce interference). Circuit by the following categories:Buck circuit - the step-down chopper, the average output voltage U0 is less than the input voltage Ui, the same polarity.Boost Circuit - step-up chopper, the average output voltage switching power supply schematic U0 is greater than the input voltage Ui, the same polarity.Buck-Boost circuit - buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, the inductance transmission.Cuk circuit - a buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, capacitance transmission.The above-mentioned non-isolated circuit, the isolation circuit forward circuits, feedback circuit, the half-bridge circuit, the full bridge circuit, push-pull circuit. Today's soft-switching technology makes a qualitative leap in the DC / DC the U.S. VICOR company design and manufacture a variety of ECI soft-switching DC / DC converter, the maximum output power 300W, 600W, 800W, etc., the corresponding power density (6.2 , 10,17) W/cm3 efficiency (80-90)%. A the Japanese Nemic Lambda latest using soft-switching technology, high frequency switching power supply module RM Series, its switching frequency (200 to 300) kHz, power density has reached 27W/cm3 with synchronous rectifier (MOSFETs instead of Schottky diodes ), so that the whole circuit efficiency by up to 90%.AC / DC conversionAC / DC conversion will transform AC to DC, the power flow can be bi-directional power flow by the power flow to load known as the "rectification", referred to as "active inverter power flow returned by the load power. AC / DC converter input 50/60Hz AC due must be rectified, filtered, so the volume is relatively large filter capacitor is essential, while experiencing safety standards (such as UL, CCEE, etc.) and EMC Directive restrictions (such as IEC, FCC, CSA) in the AC input side must be added to the EMC filter and use meets the safety standards of the components, thus limiting the miniaturization of the volume of AC / DC power, In addition, due to internal frequency, high voltage, current switching, making the problem difficult to solve EMC also high demands on the internal high-density mountingcircuit design, for the same reason, the high voltage, high current switch makes power supply loss increases, limiting the AC / DC converter modular process, and therefore must be used to power system optimal design method to make it work efficiency to reach a certain level of satisfaction.AC / DC conversion circuit wiring can be divided into half-wave circuit, full-wave circuit. Press the power phase can be divided into single-phase three-phase, multiphase. Can be divided into a quadrant, two quadrant, three quadrants, four-quadrant circuit work quadrant.he selection of the switching power supplySwitching power supply input on the anti-jamming performance, compared to its circuit structure characteristics (multi-level series), the input disturbances, such as surge voltage is difficult to pass on the stability of the output voltage of the technical indicators and linear power have greater advantages, the output voltage stability up to (0.5)%. Switching power supply module as an integrated power electronic devices should be selected。