大学本科毕业设计文献翻译模板
本科毕业论文外文翻译【范本模板】
本科毕业论文外文翻译外文译文题目:不确定条件下生产线平衡：鲁棒优化模型和最优解解法学院：机械自动化专业：工业工程学号: 201003166045学生姓名: 宋倩指导教师：潘莉日期: 二○一四年五月Assembly line balancing under uncertainty: Robust optimization modelsand exact solution methodÖncü Hazır , Alexandre DolguiComputers ＆Industrial Engineering，2013,65：261–267不确定条件下生产线平衡：鲁棒优化模型和最优解解法安库·汉泽，亚历山大·多桂计算机与工业工程，2013，65：261–267摘要这项研究涉及在不确定条件下的生产线平衡，并提出两个鲁棒优化模型。
假设了不确定性区间运行的时间。
该方法提出了生成线设计方法,使其免受混乱的破坏。
基于分解的算法开发出来并与增强策略结合起来解决大规模优化实例.该算法的效率已被测试,实验结果也已经发表。
本文的理论贡献在于文中提出的模型和基于分解的精确算法的开发.另外，基于我们的算法设计出的基于不确定性整合的生产线的产出率会更高，因此也更具有实际意义。
此外,这是一个在装配线平衡问题上的开创性工作,并应该作为一个决策支持系统的基础。
关键字：装配线平衡；不确定性; 鲁棒优化；组合优化；精确算法1.简介装配线就是包括一系列在车间中进行连续操作的生产系统。
零部件依次向下移动直到完工。
它们通常被使用在高效地生产大量地标准件的工业行业之中。
在这方面，建模和解决生产线平衡问题也鉴于工业对于效率的追求变得日益重要。
生产线平衡处理的是分配作业到工作站来优化一些预定义的目标函数。
那些定义操作顺序的优先关系都是要被考虑的,同时也要对能力或基于成本的目标函数进行优化。
就生产（绍尔，1999）产品型号的数量来说，装配线可分为三类：单一模型（SALBP）,混合模型(MALBP）和多模式（MMALBP）。
毕业设计外文翻译模板
本科生毕业设计（论文）外文翻译毕业设计（论文）题目：组合钻床动力滑台液压系统及电控系统设计外文题目： Drilling machine译文题目：组合钻床学生姓名：马莉莉专业：机械设计制造及其自动化0701班指导教师姓名：王洁评阅日期：正文内容小四号字，宋体，行距1.5倍行距。
The drilling machine is a machine for making holes with removal of chips and it is used to create or enlarge holes. There are many different types of drilling machine for different jobs, but they can be basically broken down into two categories.The bench drill is used for drilling holes through raw materials such as wood, plastic and metal and gets its name because it is bolted to bench for stability so that larger pieces of work can be drilled safely. The pillar drill is a larger version that stands upright on the floor. It can do exactly the same work as the bench drill, but because of its size it can be used to drill larger pieces of materials and produce bigger holes. Most modern drilling machines are digitally automated using the latest computer numerical control (CNC) technology.Because they can be programmed to produce precise results, over and over again, CNC drilling machines are particularly useful for pattern hole drilling, small hole drilling and angled holes.If you need your drilling machine to work at high volume, a multi spindle drill head will allow you to drill many holes at the same time. These are also sometimes referred to as gang drills.Twist drills are suitable for wood, metal and plastics and can be used for both hand and machine drilling, with a drill set typically including sizes from 1mm to 14mm. A type of drill machine known as the turret stores tools in the turret and positions them in the order needed for work.Drilling machines, which can also be referred to as bench mounted drills or floor standing drills are fixed style of drills that may be mounted on a stand or bolted to the floor or workbench. A drilling machine consists of a base, column, table, spindle), and drill head, usually driven by an induction motor.The head typically has a set of three which radiate from a central hub that, when turned, move the spindle and chuck vertically, parallel to the axis of the column. The table can be adjusted vertically and is generally moved by a rack and pinion. Some older models do however rely on the operator to lift and re clamp the table in position. The table may also be offset from the spindles axis and in some cases rotated to a position perpendicular to the column.The size of a drill press is typically measured in terms of swing which can be is defined as twice the throat distance, which is the distance from the centre of the spindle to the closest edge of the pillar. Speed change on these drilling machines is achieved by manually moving a belt across a stepped pulley arrangement.Some drills add a third stepped pulley to increase the speed range. Moderndrilling machines can, however, use a variable-speed motor in conjunction with the stepped-pulley system. Some machine shop drilling machines are equipped with a continuously variable transmission, giving a wide speed range, as well as the ability to change speed while the machine is running.Machine drilling has a number of advantages over a hand-held drill. Firstly, it requires much less to apply the drill to the work piece. The movement of the chuck and spindle is by a lever working on a rack and pinion, which gives the operator considerable mechanical advantage.The use of a table also allows a vice or clamp to be used to position and restrain the work. This makes the operation much more secure. In addition to this, the angle of the spindle is fixed relative to the table, allowing holes to be drilled accurately and repetitively.Most modern drilling machines are digitally automated using the latest computer numerical control (CNC) technology. Because they can be programmed to produce precise results, over and over again, CNC drilling machines are particularly useful for pattern hole drilling, small hole drilling and angled holes.Drilling machines are often used for miscellaneous workshop tasks such as sanding, honing or polishing, by mounting sanding drums, honing wheels and various other rotating accessories in the chuck. To add your products click on the traders account link above.You can click on the links below to browse for new, used or to hire a drilling machine.Drilling machines are used for drilling, boring, countersinking, reaming, and tapping. Several types are used in metalworking: vertical drilling machines, horizontal drilling machines, center-drilling machines, gang drilling machines, multiple-spindle drilling machines, and special-purpose drilling machines.Vertical drilling machines are the most widely used in metalworking. They are used to make holes in relatively small work-pieces in individual and small-lot production; they are also used in maintenance shops. The tool, such as a drill, countersink, or reamer, is fastened on a vertical spindle, and the work-piece is secured on the table of the machine. The axes of the tool and the hole to be drilled are aligned by moving the workpiece. Programmed control is also used to orient the workpiece and to automate the operation. Bench-mounted machines, usually of the single-spindle type, are used to make holes up to 12 mm in diameter, for instance, in instrument-making.Heavy and large workpieces and workpieces with holes located along a curved edge are worked on radial drilling machines. Here the axes of the tool and the hole to be drilled are aligned by moving the spindle relative to the stationary work-piece.Horizontal drilling machines are usually used to make deep holes, for instance, in axles, shafts, and gun barrels for firearms and artillery pieces.Center-drilling machines are used to drill centers in the ends of blanks. They are sometimes equipped with supports that can cut off the blank before centering, and in such cases they are called center-drilling machines. Gang drilling machines with more than one drill head are used to produce several holes at one time. Multiple-spindle drilling machines feature automation of the work process. Such machines can be assembled from several standardized, self-contained heads with electric motors and reduction gears that rotate the spindle and feed the head. There are one-, two-, and three-sidedmultiple-spindle drilling machines with vertical, horizontal, and inclined spindles for drilling and tapping. Several dozen such spindles may be mounted on a single machine. Special-purpose drilling machines, on which a limited range of operations is performed, are equipped with various automated devices.Multiple operations on workpieces are performed by various combination machines. These include one- and two-sided jig boring machines,drilling-tapping machines (usually gang drilling machines with reversible thread-cutting spindles), milling-type drilling machines and drilling-mortising machines used mainly for woodworking, and automatic drilling machines.In woodworking much use is made of single- and multiple-spindle vertical drilling machines, one- and two-sided, horizontal drilling machines (usually with multiple spindles), and machines equipped with a swivel spindle that can be positioned vertically and horizontally. In addition to drilling holes, woodworking machines may be used to make grooves, recesses, and mortises and to remove knots.英文翻译指导教师评阅意见。
大学本科毕业设计文献翻译模板
模型预测油田水中溶解的碳酸钙含量：压力和温度的影响XXX 译摘要：油田中水垢沉积会对储层造成伤害、堵塞地层孔道、表面以及注入设备。
碳酸钙是水中最常见的结垢化合物之一，储层产生的盐水会使压力和温度降低，储层压力降低会使CaCO3的溶解度降低，进而提高体系中碳酸钙的饱和速率，而温度下降会产生相反的结果。
因此温度和压力一起作用的结果可能增加或减小CaCO3溶解度，用体系温度的变化来指定其压力的变化。
因此，在石油生产系统中精确的预测方法的应用备受关注。
目前的研究重点是运用基于最小二乘支持向量机(LSSVM)预测模型来估计油田水中溶解碳酸钙浓度的大小。
用超优化参数（r和C2）的遗传算法（GA）嵌入到LSSVM模型，这种方法可简单准确的预测油田卤水中溶解碳酸钙浓度的最小量。
1.引言随着油田卤水压力和温度变化，气体可能会从储层到地表的运动，导致某些固体沉淀。
为了保持注水井压力平衡并将油运移到生产井，有时需要将卤水注入到储层中，因此，过量的盐垢可以沉积在储层或井眼内。
对于大部分油田结垢多会发生在此过程中。
碳酸钙沉积通常是一个自发的过程，沉积形成的主要原因是二氧化碳从水相逸出，导致油气层的压力下降，该过程会除去了水中的碳酸，直到方解石溶解完全。
在恒定二氧化碳分压下，方解石的溶解性随温度的降低而降低[1-4]。
根据公式（1），碳酸钙沉积垢来自碳酸钙沉淀：Ca2+ + CO32-→ CaCO3↓下面的公式为碳酸的电离式[5–7]：CO2 + H2O → H2CO3H2CO3→ H+ + HCO3-HCO3-→ H+ + CO32-若要形成碳酸氢根离子和氢离子，碳酸要电离，因为碳酸的第一电离常数远大于它的第二电离常数，从碳酸第一电离离子化的氢离子与水中自由的碳酸根离子结合。
此外，碳酸钙沉淀的方程式可以说明[8–10]：Ca(HCO3)2→CaCO3↓+ CO2↑+ H2O碳酸钙的溶解度很大程度上取决于二氧化碳在水中的含量（即二氧化碳气体逸出时所需最小的分压）[10–12]。
毕业设计论文外文文献翻译
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(论文)外文翻译【范本模板】
华南理工大学广州学院本科生毕业设计(论文）翻译英文原文名Review of Vibration Analysis Methods for Gearbox Diagnostics and Prognostics中文译名对变速箱振动分析的诊断和预测方法综述学院汽车工程学院专业班级车辆工程七班学生姓名刘嘉先学生学号201130085184指导教师李利平填写日期2015年3月15日英文原文版出处：Proceedings of the 54th Meeting of the Society for Machinery Failure Prevention Technology, Virginia Beach，V A, May 1-4，2000，p. 623-634译文成绩：指导教师(导师组长）签名：译文：简介特征提取技术在文献中有描述;然而，大多数人似乎掩盖所需的特定的预处理功能。
一些文件没有提供足够的细节重现他们的结果，并没有一个全面的比较传统的功能过渡齿轮箱数据。
常用术语,如“残差信号”,是指在不同的文件不同的技术.试图定义了状态维修社区中的常用术语和建立所需的特定的预处理加工特性。
本文的重点是对所使用的齿轮故障检测功能。
功能分为五个不同的组基于预处理的需要。
论文的第一部分将提供预处理流程的概述和其中每个特性计算的处理方案。
在下一节中，为特征提取技术描述，将更详细地讨论每一个功能。
最后一节将简要概述的宾夕法尼亚州立大学陆军研究实验室的CBM工具箱用于齿轮故障诊断。
特征提取概述许多类型的缺陷或损伤会增加机械振动水平。
这些振动水平，然后由加速度转换为电信号进行数据测量。
原则上,关于受监视的计算机的健康的信息被包含在这个振动签名。
因此，新的或当前振动签名可以与以前的签名进行比较,以确定该元件是否正常行为或显示故障的迹象。
在实践中，这种比较是不能奏效的。
由于大的变型中,签名的直接比较是困难的。
相反,一个涉及从所述振动署名数据特征提取更多有用的技术也可以使用。
本科毕业设计外文文献翻译
（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。
毕业设计英文翻译》【范本模板】
外文文献翻译（译成中文1000字左右）：【主要阅读文献不少于5篇，译文后附注文献信息，包括：作者、书名（或论文题目）、出版社（或刊物名称）、出版时间（或刊号）、页码。
提供所译外文资料附件(印刷类含封面、封底、目录、翻译部分的复印件等，网站类的请附网址及原文】太阳能—地源热泵的热源性能Y。
Bi1,2，L. Chen1＊and C. Wu3本论文研究了中国天津冬季里的太阳能—地源热泵的太阳能与地源性能。
结果被用于设计和分析的太阳能集热器和地面热交换器。
太阳能-地源热泵在这个地区的使用可行性是成立的. 关键词：太阳能，地源热泵，可行性。
介绍地源热泵（GSHP）利用地下相对稳定的温度作为热源或水槽提供热源或调节空气。
GSHP 系统寻求利用常规空气—空气热泵系统的两方面可用的功能。
首先，地下环境温度缓慢地变化，归结于其高的热质量，导致了相对稳定的源或者散热器的温度而不受较大的极限。
其次，被地面吸收的太阳能在整个冬季可以热源。
自从地源热泵的观念在二十世纪四十年代被发展，大量的理论和实验工作都完成了，实验研究审查了具体的地源热泵系统和现场数据。
理论研究已经集中于用数值方法模拟地下盘管换热器以及研究参数对系统性能的影响。
太阳能—地源热泵（SGSHP)采用太阳能集热器和大地作为热源开始发展于1982年。
热泵实验系统用垂直双螺旋线圈（VSDC）地下换热器(GHX)为太阳能—地源热泵（SGSHP）利用低品位能源，这种方法已经被作者们所创造。
（图1）蒸汽压缩热泵的加热负荷和性能系数（COP）取决于蒸发温度和热源温度。
SGSHP采用太阳能集热器和大地作为热源,因此，其应用主要是依靠太阳能和土壤源性能。
在本论文中，中国天津的气象数据被用来分析SGSHP在该区域的应用可行性。
太阳能源分析天津的太阳能在中国处于中等水平。
1966—1976年期间天津的太阳能辐射月平均变化如图2所示。
结果表明，该太阳能集热器在夏天可以直接用于提供热水。
(完整版)本科生_毕业设计说明书外文文献及翻译_
Computer networking summarizeNetworking can be defined as the linking of people, resources and ideas. Networking occurs via casual encounters, meetings, telephone conversation, and the printed words. Now the computer networking provide beings with new networking capabilities. Computer network are important for services because service tasks are information intensive. During the is transmitted between clients, coworkers, management, funding sources, and policy makers. Tools with rapidly speed up communication will dramatically affect services.Computer network growing explosively. Two decades ago, few people essential part of our infrastructure. Networking is used in every aspect of business, including advertising, production, shipping, planning, bulling, and accounting. Consequently, most corporations in on-line libraries around the world. Federal, state, and local government offices use networks, as do military organizations. In short, computer networks are everywhere.The growth in networking economic impact as well. An entire industry jobs for people with more networking expertise. Companies need workers to plan, acquire, install, operate, and manage the addition computer programming is no longer restricted to individual computers; programmers are expected to design and implement application software that can communicate with software on other computers.Computer networks link computers by communication lines and software protocols, allowing data to be exchanged rapidly and reliably. Traditionally, they split between wide area networks (WANs) and local area networks (LANs). A WAN is a network connected over long-distance telephone lines, and a LAN is a localized network usually in one building or a group of buildings close together. The distinction, computers. Today networks carry e-mail, provide access to public databases, and are beginning to be used for distributed systems. Networks also allow users in one locality to share expensive resources, such as printers and disk-systems.Distributed computer systems are built using networked computers that cooperate to perform tasks. In this environment, each part of the networked system does what it is best at. The of a personal computer or workstation provides a good user interface. The mainframe, on the other the results to the users. In a distributed environment, a user might use in a special language (e. g. Structured Query Language-SQL), to the mainframe, which then parrrses the query, returning the user only the data requested. The user might then use the data. By passing back the user’s PC only the specific information requested, network traffic is reduced. If the whole file were transmitted, the PC would then of one network to access the resources on a different type of network. For example, a gateway could be used to connect a local area network of personal computers to a mainframe computer network. For example, if a company this example, using a bridge makes more sense than joining all thepersonal computers together in one large network because the individual departments only occasionally need to access information on the other network.Computer networking technology can be divided into four major aspects.The first is the data transmission. It explains that at the lowest level electrical signals traveling across wires are used to carry information, and shows be encoded using electrical signals.The second focuses on packet transmission. It explains why computer network use packets, and shows . LANs and WANs discussed above are two basic network.The third covers internetworking—the important idea that allows system, and TCPIP, the protocol technology used in global internet.The fourth explains networking applications. It focuses on , and programs provide services such as electronic mail and Web browsing.Continued growth of the global Internet is one of most interesting and exciting phenomena in networking. A decade ago, the Internet was a research project that involved a few dozen sites. Today, the Internet into a production communication system that reaches millions of people in almost all countries on all continents around the world. In the United States, the Internet connects most corporations, colleges and universities, as well as federal, state, and local government offices. It will soon reach most elementary,junior, and senior addition, many private residences can reach the Internet through a dialup telephone connection. Evidence of the Internet’s impact on society can be seen in advertisements, in magazines and on television, which often contain a reference to an Internet Web site that provide additional information about the advertiser’s products and services.A large organization with diverse networking requirements needs multiple physical networks. More important, if the organization chooses the type network that is best for each task, the organization will network can only communicate with other computers attached to same network. The problem became evident in the 1970s as large organizations began to acquire multiple networks. Each network in the organizations formed an island. In many early installations, each computer attached to a single network and employees employees was given access to multiple svreens and keyboards, and the employee was forced to move form one computer to another to send a massage across the appropriate network. Users are neither satisfied nor productive when they must use a separate computer. Consequently, most modern computer communication syetem allow communication between any two computers analogous to the way a telephone system provides communication between any two telephones. Known as universal service, the concept is a fundamental part of networking. With universal service, a user on any computer in any part of an organization can send messages or data to any other users. Furthermore, a user does not need to change computer systems whenchanging tasks—all information is available to all computers. As a result, users are more productive.The basic component used to commect organization to choose network technologies appropriate for each need, and to use routers to connect all networks into a single internet.The goal of internetworking is universal service across an internet, routers must agree to forward information from a source on one network to a specified destination on another. The task is complex because frame formats and addressing schemes used by underlying networks can differ. As s resulrt, protocol software is needed on computers and routers make universal service possible. Internet protocols overcome differences in frame formats and physical addresses to make communication pissible among networks that use different technologies.In general, internet software provides the appeatrance of a single, seamless communication system to which many computers attach. The syetem offers universal service :each computer is assigned an address, and any computer can send a packet to any other computer. Furthermore, internet protocol software —neither users nor application programs are a ware of the underlying physical networks or the routers that connect them.We say that an internet is a virtual network system because the communication system is an abstraction. That is, although a combination of of a uniform network syetem, no such network exists.Research on internetworking modern networking. In fact,internet techmology . Most large organizations already use internetworking as primary computer communication mechanism. Smaller organizations and individuals are beginning to do so as well. More inportant, the TCPIP technology computers in schools, commercial organications, government, military sites and individuals in almost all countries around the world.电脑网络简述网络可被定义为人、资源和思想的联接。
文献翻译模板
2016届本科毕业设计（论文）文献翻译题目宋体三号字，加粗学院宋体四号字专业宋体四号字班级宋体四号字学号宋体四号字姓名宋体四号字指导教师宋体四号字开题日期宋体四号字文献一：（宋体五号）英文题目(居中，Times New Roman字体，三号加粗)正文（英文不少于10000印刷符号，Times New Roman字体，五号，首行缩进2.5字符，单倍行距，两边对齐）翻译一：（宋体五号，另起一页）中文题目(居中，黑体，三号加粗)正文（中文不少于2000字，宋体，五号，单倍行距，首行缩进2字符）文献二：（宋体五号，另起一页）英文题目(居中，Times New Roman字体，三号加粗)正文（英文不少于10000印刷符号，Times New Roman字体，五号，首行缩进2.5字符，单倍行距，两边对齐）翻译二：（宋体五号，另起一页）中文题目(居中，黑体，三号加粗)正文（中文不少于2000字，宋体，五号，单倍行距，首行缩进2字符）（请参照下面模板）文献一：Research on Spillover Effect of Foreign Direct Investment1. IntroductionIn recent decades, economists have begun to identify technical progress, or more generally, knowledge creation, as the major determinant of economic growth. Until the 1970s, the analysis of economic growth was typically based on neoclassical models that explain growth with the accumulation of labor, capital, and other production factors with diminishing returns to scale. In these models, the economy converges to steady state equilibrium where the level of per capita income is determined by savings and investment, depreciation, and population growth, but where there is no permanent income growth. Any observed income growth per capita occurs because the economy is still converging towards its steady state, or because it is in transition from one steady state to another.The policies needed to achieve growth and development in the framework of these models is therefore straightforward: increases in savings and investments and reductions in the population growth rate, shift the economy to a higher steady state income level. From the view of developing countries, however, these policies are difficult to implement. Low income and development levels are not only consequences, but also causes of low savings and high population growth rates. The importance of technical progress was also recognized in the neoclassical growth models, but the determinants of the level of technology were not discussed in detail; instead, technology was seen as an exogenous factor. Yet, it was clear that convergence in income percapita levels could not occur unless technologies converged as well.From the 1980s and onwards, growth research has therefore increasingly focused on understanding and ontogenetic technical progress. Modern growth theory is largely built on models with constant or increasing returns to reproducible factors as a result of the accumulation of knowledge. Knowledge is, to some extent, a public good, and R&D, education, training, and other investments in knowledge creation may generate externalities that prevent diminishing returns to scale for labor and physical capital. Taking this into account, the economy may experience positive long-run growth instead of the neoclassical steady state where per capita incomes remain unchanged. Depending on the economic starting point, technical progress and growth can be based on creation of entirely new knowledge, or adaptation and transfer of existing foreign technology.Along with international trade, the most important vehicle for international technology transfer is foreign direct investment (FDI). It is well known that multinational corporations (MNCs) undertake a major part of the world’s private R&D efforts and production, own and control most of the world’s advanced technology. When a MNC sets up a forei gn affiliate, the affiliate receives some amount of the proprietary technology that constitutes the parent’s firm specific advantage and allows it to compete successfully with local firms that have superior knowledge of local markets, consumer preferences, and business practices. This leads to a geographical diffusion of technology, but not necessarily to any formal transfer of technology beyond the boundaries of the MNCs; the establishment of a foreign affiliate is, almost per definition, a decision to internalize the use of core technology.However, MNC technology may still leak to the surrounding economy through external effects or spillovers that raise the level of human capital in the host country and createproductivity increases in local firms. In many cases, the effects operate through forward and backward linkages, as MNCs provide training and technical assistance to their local suppliers, subcontractors, and customers. The labor market is another important channel for spillovers, as almost all MNCs train operatives and managers who may subsequently take employment in local firms or establish entirely new companies.It is therefore not surprising that attitudes towards inward FDI have changed considerably over the last couple of decades, as most countries have liberalized their policies to attract all kinds of foreign investment. Numerous governments have even introduced various forms of investment incentives to encourage foreign MNCs to invest in their jurisdiction. However, productivity and technology spillovers are not automatic consequences of FDI. Instead, FDI and human capital interact in a complex manner, where FDI inflows create a potential for spillovers of knowledge to the local labor force, at the same time as the host country’s level of human capital determines how much FDI it can attract and whether local firms are able to absorb the potential spillover benefits.2. Foreign Direct Investment and SpilloversThe earliest discussions of spillovers in the literature on foreign direct investment date back to the 1960s. The first author who systematically introduced spillovers (or external effects) among the possible consequences of FDI was MacDougall (1960), who analyzed the general welfare effects of foreign investment. The common aim of the studies was to identify the various costs and benefits of FDI.Productivity externalities were discussed together with several other indirect effects that influence the welfare assessment, such as those arising from the impact of FDI on government revenue, tax policies, terms of trade, and the balance of payments. The fact that spillovers included in the discussion was generally motivated by empirical evidence from case studies rather than by comprehensive theoretical arguments.Yet, the early analyses made clear that multinationals may improve locatives efficiency by entering into industries with high entry barriers and reducing monopolistic distortions, and induce higher technical efficiency if the increased competitive pressure or some demonstration effect spurs local firms to more efficient use of existing resources. They also proposed that the presence may lead to increases in the rate of technology transfer and diffusion. More specifically, case studies showed that foreign MNCs may:(1) Contribute to efficiency by breaking supply bottlenecks (but that the effect may become less important as the technology of the host country advances);(2) Introduce new know-how by demonstrating new technologies and training workers who later take employment in local firms;(3) Either break down monopolies and stimulate competition and efficiency or create a more monopolistic industry structure, depending on the strength and responses of the local firms;(4) Transfer techniques for inventory and quality control and standardization to their local suppliers and distribution channels;Although this diverse list gives some clues about the broad range of various spillover effects, it says little about how common or how important they are in general. Similar complaints can be made about the evidence on spillovers gauged from the numerous case studies discussing various aspects of FDI in different countries and industries. These studies often contain valuable circumstantial evidence of spillovers, but often fail to show how significant the spillover effectsare and whether the results can be generalized.For instance, many analyses of the linkages between MNCs and their local suppliers and subcontractors have documented learning and technology transfers that may make up a basis for productivity spillovers or market access spillovers. However, these studies seldom reveal whether the MNCs are able to extract all the benefits that the new technologies or information generate among their supplier firms. Hence, there is no clear proof of spillovers, but it is reasonable to assume that spillovers are positively related to the extent of linkages.Similarly, there are many works on the relation between MNCs entry and presence and market structure in host countries, and this is closely related to the possible effects of FDI on competition in the local markets. There are also case studies of demonstration effects, technology diffusion, and labor training in foreign MNCs. However, although these studies provide much detailed information about the various channels for spillovers, they say little about the overall significance of such spillovers.The statistical studies of spillovers, by contrast, may reveal the overall impact of foreign presence on the productivity of local firms, but they are generally not able to say much about how the effects come about. These studies typically estimate production functions for locally owned firms, and include the foreign share of the industry as one of the explanatory variables. They then test whether foreign presence has a significant positive impact on local productivity once other firm and industry characteristics have been accounted.Research conclude that domestic firms exhibited higher productivity in sectors with a larger foreign share, but argue that it may be wrong to conclude that spillovers have taken place if MNC affiliates systematically locate in the more productive sectors. In addition, they are also able to perform some more detailed tests of regional differences in spillovers. Examining the geographical dispersion of foreign investment, they suggest that the positive impact of FDI accrue mainly to the domestic firms located close to the MNC affiliates. However, effects seem to vary between industries.The results on the presence of spillovers seem to be mixed; recent studies suggest that there should be a systematic pattern where various host industry and host country characteristics influence the incidence of spillovers. For instance, the foreign affiliate’s levels of tech nology or technology imports seem to influence the amount of spillovers to local firms. The technology imports of MNC affiliates, in turn, have been shown to vary systematically with host country characteristics. These imports seem larger in countries and industries where the educational level of the local labor force is higher, where local competition is tougher, and where the host country imposes fewer formal requirements on the affiliates’ operations.Some recent studies have also addressed the apparent contradictions between the earlier statistical spillover studies, with the hypothesis that the host country’s level of technical development or human capital may matter as a starting point.In fact, in some cases, large foreign presence may even be a sign of a weak local industry, where local firms have not been able to absorb any productivity spillovers at all and have therefore been forced to yield market shares to the foreign MNCs.3. FDI Spillover and Human Capital DevelopmentThe transfer of technology from MNC parents to its affiliates and other host country firms is not only mbodied in machinery, equipment, patent rights, and expatriate managers and technicians,but is also realized rough the training of local employees. This training affects most levels of employees, from simple manufacturing operatives through supervisors to technically advanced professionals and top-level managers. While most recipients of training are employed in the MNCs own affiliates, the beneficiaries also include employees among the MNCs suppliers, subcontractors, and customers.Types of training ranged from on-the-job training to seminars and more formal schooling to overseas education, perhaps at the parent company, depending on the skills needed. The various skills gained through the elation with the foreign MNCs may spill over directly when the MNCs do not charge the full value of the training provided to local firms or over time, as the employees move to other firms or set up their own businesses.While the role of MNCs in primary and secondary education is marginal, there is increasingly clear evidence hat FDI may have a noticeable impact on tertiary education in their host countries. The most important effect is perhaps on the demand side. MNCs provide attractive employment opportunities to highly skilled graduates in natural sciences, engineering, and business sciences, which may be an incentive for gifted students to complete tertiary training, and MNCs demand skilled labor, which may encourage governments to invest in higher education.Many studies undertaken in developing countries have emphasized the spillovers of management skills. There is evidence of training and capacity development in technical areas, although the number of detailed studies appears smaller.While training activities in manufacturing often aim to facilitate the introduction of new technologies that are embodied in machinery and equipments, the training in service sectors is more directly focused on strengthening skills and know-how embodied in employees. This means that training and human capital development are often more important in service industries. Furthermore, many services are not tradable across international borders, which mean that service MNCs to a great extent are forced to reproduce home country technologies in their foreign affiliates. As a consequence, service companies are often forced to invest more in training, and the gap between affiliate and parent company wages tends, therefore, to be smaller than that in manufacturing.4. ConclusionThis paper has noted that the interaction of FDI and spillovers is complex and highly non-linear, and that several different outcomes are possible. FDI inflows create a potential for spillovers of knowledge to the local labor force, at the same time as the host country’s level of human capital determines how much FDI it can attract and whether local firms are able to absorb the potential spillover benefits. Hence, it is possible that host economies with relatively high levels of human capital may be able to attract large amounts of technology intensive foreign MNCs that contribute significantly to the further development of labor skills. At the same time, economies with weaker initial conditions are likely to experience smaller inflows of FDI, and those foreign firms that enter are likely to use simpler technologies that contribute only marginally to local learning and skill development.翻译一：外商直接投资溢出效应研究1.引言在最近几十年中，经济学家们已开始确定技术进步，或更普遍认为知识创造，作为经济增长原动力的一个重要决定因素，直到20世纪70年代，分析经济增长运用典型的新古典主义模型来解释经济增长的积累，劳动力、资本等生产要素与收益递减的规模。
本科毕业设计文献翻译
中文翻译2．1理想蜂窝小区的覆盖范围根据标准传播模型SPM，各个地区针对不同的无线信号频段分别进行传播模型校正，得到较适合该地区该频段的传播模型：d表示接收机与基站间的距离；HT x为发射机高度；HRx为接收机高度；DiffLoss表示散射造成的路径损耗；f(clutter)表示各个clutter损耗的加权平均，表示为Kc。
通常情况下，一个区域内的移动终端接收电平在-85dBm以上，可以认为该区域有较良好的无线网络覆盖。
因此蜂窝基站小区覆盖边界处的接收电平为-85dBm、平均天线口发射功率51dBm来推算理论覆盖范围。
2．2 GSM理论网络容量与载干比C/I间的计算方法载干比C/I通常被用来衡量GSM网络的移动通话质量若使用MRP（多重频率复用方式）来进行频率规划的话，则理论计算规划可实现的C/I，可以应用以下的公式大致推算出：其中a表示传播模型中的路径损耗斜率；D表示相邻2个小区群中位置相对应的2个小区中心之间的距离，即最近同频小区距离，也称为频率复用距离；R 为小区六边形外接圆半径，即小区覆盖半径；Ki为传播条件、天线方向去耦、天线下倾等因素的综合修正因子（建议取值范围为-5~0）。
针对一个地区具体的网络a和Ki为相对固定的值。
2．3 GSM系统网络容量与无线通话质量间的关系GSM网络无线通话质量的主要衡量标准为载干比C/I，当一块区域的GSM网络载干比C/I>9dB时，可以认为该区域拥有较好无线通话质量。
从章节2.2中的公式中得到推论，在一个确定的无线环境中，蜂窝小区连续均匀覆盖，即小区的覆盖距离为定值，若载干比C/I值恒定，则GSM理论网络容量与可用载频数成正比。
若GSM理论网络容量恒定，则载干比C/I值与可用载频数成正比。
3．2 COMMON BCCH技术COMMON BCCH是双频共BTS的一种方式，利用DCS1800M的无线频率资源来补充GSM900M的单蜂窝扇区的载频数，从而实现容量上的增加。
毕业设计论文翻译（译文+原文）
Hacking tricks toward security on network environments Tzer-Shyong Chen1, Fuh-Gwo Jeng 2, and Yu-Chia Liu 11 Department of Information Management, Tunghai University, Taiwan2 Department of Applied Mathematics, National Chiayi University, TaiwanE-Mail:****************.edu.twAbstractMounting popularity of the Internet has led to the birth of Instant Messaging, an up-and-coming form of Internet communication. Instant Messaging is very popular with businesses and individuals since it has instant communication ability. As a result, Internet security has become a pressing and important topic for discussion. Therefore, in recent years, a lot of attention has been drawn towards Internet security and the various attacks carried out by hackers over the Internet. People today often handle affairs via the Internet. For instance, instead of the conventional letter, they communicate with others by e-mails; they chat with friends through an instant messenger; find information by browsing websites instead of going to the library; perform e-commerce transactions through the Internet, etc. Although the convenience of the Internet makes our life easier, it is also a threat to Internet security. For instance, a business email intercepted during its transmission may let slip business confidentiality; file transfers via instant messengers may also be intercepted, and then implanted with backdoor malwares; conversations via instant messengers could be eavesdropped. Furthermore, ID and password theft may lose us money when using Internet bank service. Attackers on the Internet use hacking tricks to damage systems while users are connected to the Internet. These threats along with possible careless disclosure of business information make Instant Messaging a very unsafe method of communication for businesses. The paper divides hacking tricks into three categories: (1) Trojan programs that share files via instant messenger. (2) Phishing or fraud via e-mails. (3) Fake Websites. Keywords:Hacking tricks, Trojan programs, Phishing, Firewall, Intrusion detection system.1. IntroductionIncreasingly more people are using instant messengers such as MSN Messenger, Yahoo! Messenger, ICQ, etc as the media of communication. These instant messengers transmit alphanumeric message as well as permit file sharing. During transfer, a file may be intercepted by a hacker and implanted with backdoor malware. Moreover, the e-mails users receive every day may include Spam, advertisements, and fraudulent mail intended to trick uninformed users. Fake websites too are prevalent. Websites which we often visit could be counterfeited by imitating the interface and the URL of the original, tricking users. The paper classifies hacking tricks into three categories which are explained in the following sections.2. Hacking TricksThe paper divides hacking tricks into three categories: (1) Trojan programs that share files via instant messenger. (2) Phishing (3) Fake Websites.2.1 Trojan programs that share files via instant messengerInstant messaging allows file-sharing on a computer [9]. All present popular instant messengers have file sharing abilities, or allow users to have the above functionality by installing patches or plug-ins; this is also a major threat to present information security. These communication softwares also makeit difficult for existing hack prevention methods to prevent and control information security. Therefore, we shall discuss how to control the flow of instant messages and how to identify dangerous user behavior.Hackers use instant communication capability to plant Trojan program into an unsuspected program; the planted program is a kind of remotely controlled hacking tool that can conceal itself and is unauthorized. The Trojan program is unknowingly executed, controlling the infected computer; it can read, delete, move and execute any file on the computer. The advantages of a hacker replacing remotely installed backdoor Trojan programs [1] with instant messengers to access files are:When the victim gets online, the hacker will be informed. Thus, a hacker can track and access the infected computer, and incessantly steal user information.A hacker need not open a new port to perform transmissions; he can perform his operations through the already opened instant messenger port.Even if a computer uses dynamic IP addresses, its screen name doesn’t change.Certain Trojan programs are designed especially for instant messengers. These Trojans can change group settings and share all files on the hard disk of the infected computer. They can also destroy or modify data, causing data disarray. This kind of program allows a hacker access to all files on an infected computer, and thus poses a great threat to users. The Trojan program takes up a large amount of the resources of the computer causing it to become very slow and often crashes without a reason.Trojan programs that access a user computer through an instant messenger are probably harder to detect than classic Trojan horse programs. Although classic Trojan intrudes a computer by opening a listening or outgoing port which is used to connect toa remote computer, a desktop firewall can effectively block such Trojans. Alternatively, since it is very difficult for the server’s firewall to spot intrusion by controlling an instant messenger’s flow, it is extremely susceptible to intrusion.Present Trojan programs have already successfully implemented instant messengers. Some Trojan programs are Backdoor Trojan, AIMVision, and Backdoor. Sparta.C. Backdoor Trojans use ICQ pager to send messages to its writer. AIMVision steals AIM related information stored in the Windows registry, enabling a hacker to setup an AIM user id. Backdoor. Sparta.C uses ICQ to communicate with its writer and opens a port on an infected host and send its IP Address to the hacker, and at the same time attempts to terminate the antivirus program or firewall of the host.2.1.1 Hijacking and ImpersonationThere are various ways through which a hacker can impersonate other users [7]. The most commonly used method is eavesdropping on unsuspecting users to retrieve user accounts, passwords and other user related information.The theft of user account number and related information is a very serious problem in any instant messenger. For instance, a hacker after stealing a user’s information impersonate the user; the user’s contacts not knowing that the user’s account has been hacked believe that the person they’re talking to is the user, and are persuaded to execute certain programs or reveal confidential information. Hence, theft of user identity not only endangers a user but also surrounding users. Guarding against Internet security problems is presently the focus of future research; because without good protection, a computer can be easily attacked, causing major losses.Hackers wishing to obtain user accounts may do so with the help of Trojans designed to steal passwords. If an instant messenger client stores his/her password on his/her computer, then a hacker can send a Trojan program to the unsuspecting user. When the user executes the program, the program shall search for the user’s password and send it to the hacker. There are several ways through which a Trojan program can send messages back to the hacker. The methods include instant messenger, IRC, e-mails, etc.Current four most popular instant messengers are AIM, Yahoo! Messenger, ICQ, and MSN Messenger, none of which encrypts its flow. Therefore, a hackercan use a man-in-the-middle attack to hijack a connection, then impersonate the hijacked user and participate in a chat-session. Although difficult, a hacker can use the man-in-the-middle attack to hijack the connection entirely. For example, a user may receive an offline message that resembles that sent by the server, but this message could have been sent by the hacker. All at once, the user could also get disconnected to the server. Furthermore, hackers may also use a Denial of Service (DoS) tool or other unrelated exploits to break the user’s connection. However, the server keeps the connection open, and does not know that the user has been disconnected; thus allowing the hacker to impersonate the user. Moreover, since the data flow is unencrypted and unauthenticated, a hacker can use man-in-the-middle attacks that are similar to that of ARP fraud to achieve its purpose.2.1.2 Denial of Service (DoS)There are many ways through which a hacker can launch a denial of service (DoS) attack [2] on an instant messenger user. A Partial DoS attack will cause a user end to hang, or use up a large portion of CPU resources causing the system to become unstable.Another commonly seen attack is the flooding of messages to a particular user. Most instant messengers allow the blocking of a particular user to prevent flood attacks. However, a hacker can use tools that allow him to log in using several different identities at the same time, or automatically create a large number of new user ids, thus enabling a flood attack. Once a flood attack begins, even if the user realizes that his/her computer has been infected, the computer will not be able to respond. Thus, the problem cannot be solved by putting a hacker’s user id on the ignore list of your instant messenger.A DoS attack on an instant messenger client is only a common hacking tool. The difficulty of taking precautions against it could turn this hacking tool into dangerous DoS type attacks. Moreover, some hacking tools do not just cause an instant messenger client to hang, but also cause the user end to consume large amount of CPU time, causing the computer to crash.2.1.3 Information DisclosureRetrieving system information through instant messenger users is currently the most commonly used hacking tool [4]. It can effortlessly collect user network information like, current IP, port, etc. IP address retriever is an example. IP address retrievers can be used to many purposes; for instance, a Trojan when integrated with an IP address retriever allows a hacker to receive all information related to the infected computer’s IP address as soon as the infected computer connects to the internet. Therefore, even if the user uses a dynamic IP address, hackers can still retrieve the IP address.IP address retrievers and other similar tools can also be used by hackers to send data and Trojans to unsuspecting users. Hackers may also persuade unsuspecting users to execute files through social engineering or other unrelated exploits. These files when executed search for information on the user’s computer and sends them back to the hacker through the instant messenger network.Different Trojan programs were designed for different instant messaging clients. For example, with a user accounts and password stealing Trojans a hacker can have full control of the account once the user logs out. The hacker can thus perform various tasks like changing the password and sending the Trojan program to all of the user’s contacts.Moreover, Trojans is not the only way through which a hacker can cause information disclosure. Since data sent through instant messengers are unencrypted, hackers can sniff and monitor entire instant messaging transmissions. Suppose an employee of an enterprise sends confidential information of the enterprise through the instant messenger; a hacker monitoring the instant messaging session can retrieve the data sent by the enterprise employee. Thus, we must face up to the severity of the problem.2.2 PhishingThe word “Phishing” first appeared in 1996. It is a variant of ‘fishing’, and formed by replacing the ‘f’ in ‘fishing’ with ‘ph’ from phone. It means tricking users of their money through e-mails.Based on the statistics of the Internet Crime Complaint Center, loss due to internet scam was as high as $1.256 million USD in 2004. The Internet Crime Complaint Center has listed the above Nigerian internet scam as one of the ten major internet scams.Based on the latest report of Anti-Phishing Working Group (APWG) [8], there has been a 28% growth of Phishing scams in the past 4 months, mostly in the US and in Asia. Through social engineering and Trojans, it is very difficult for a common user to detect the infection.To avoid exploitation of your compassion, the following should be noted:(1)When you need to enter confidentialinformation, first make sure that theinformation is entered via an entirely secureand official webpage. There are two ways todetermine the security of the webpage:a.The address displayed on the browserbegins with https://, and not http://. Payattention to if the letter ‘s’ exists.b.There is a security lock sign on the lowerright corner of the webpage, and whenyour mouse points to the sign, a securitycertification sign shall appear.(2)Consider installing a browser security softwarelike SpoofStick which can detect fake websites.(3)If you suspect the received e-mail is a Phishinge-mail, do not open attachments attached to theemail. Opening an unknown attachment couldinstall malicious programs onto your computer.(4)Do not click on links attached to your emails. Itis always safer to visit the website through theofficial link or to first confirm the authenticityof the link. Never follow or click on suspiciouslinks in an e-mail. It is advisable to enter theURL at the address bar of the web browser,and not follow the given link.Generally speaking, Phishing [3] [5] is a method that exploits people’s sympathy in the form of aid-seeking e-mails; the e-mail act as bait. These e-mails usually request their readers to visit a link that seemingly links to some charitable organization’s website; but in truth links the readers to a website that will install a Trojan program into the reader’s computer. Therefore, users should not forward unauthenticated charity mails, or click on unfamiliar links in an e-mail. Sometimes, the link could be a very familiar link or an often frequented website, but still, it would be safer if you’d type in the address yourself so as to avoid being linked to a fraudulent website. Phisher deludes people by using similar e-mails mailed by well-known enterprises or banks; these e-mails often asks users to provide personal information, or result in losing their personal rights; they usually contain a counterfeit URL which links to a website where the users can fillin the required information. People are often trapped by phishing due to inattentionBesides, you must also be careful when using a search engine to search for donations and charitable organizations.2.3 Fake WebsitesFake bank websites stealing account numbers and passwords have become increasingly common with the growth of online financial transactions. Hence, when using online banking, we should take precautions like using a secure encrypted customer’s certificate, surf the net following the correct procedure, etc.There are countless kinds of phishing baits, for instance, messages that say data expired, data invalid, please update data, or identity verification intended to steal account ID and matching password. This typeof online scam is difficult for users to identify. As scam methods become finer, e-mails and forged websites created by the impostor resemble their original, and tremendous losses arise from the illegal transactions.The following are methods commonly used by fake websites. First, the scammers create a similar website homepage; then they send out e-mails withenticing messages to attract visitors. They may also use fake links to link internet surfers to their website. Next, the fake website tricks the visitors into entering their personal information, credit card information or online banking account number and passwords. After obtaining a user’s information, the scammers can use the information to drain the bank accounts, shop online or create fake credit cards and other similar crimes. Usually, there will be a quick search option on these fake websites, luring users to enter their account number and password. When a user enters their account number and password, the website will respond with a message stating that the server is under maintenance. Hence, we must observe the following when using online banking:(1)Observe the correct procedure for entering abanking website. Do not use links resultingfrom searches or links on other websites.(2)Online banking certifications are currently themost effective security safeguard measure. (3)Do not easily trust e-mails, phone calls, andshort messages, etc. that asks for your accountnumber and passwords.Phishers often impost a well-known enterprise while sending their e-mails, by changing the sender’s e-mail address to that of the well known enterprise, in order to gain people’s trust. The ‘From’ column of an e-mail is set by the mail software and can be easily changed by the web administrator. Then, the Phisher creates a fake information input website, and send out e-mails containing a link to this fake website to lure e-mail recipients into visiting his fake website.Most Phishers create imitations of well known enterprises websites to lure users into using their fake websites. Even so, a user can easily notice that the URL of the website they’re entering has no relation to the intended enterprise. Hence, Phishers may use different methods to impersonate enterprises and other people. A commonly used method is hiding the URL. This can easily be done with the help of JavaScript.Another way is to exploit the loopholes in an internet browser, for instance, displaying a fake URL in the browser’s address bar. The security loophole causing the address bar of a browser to display a fake URL is a commonly used trick and has often been used in the past. For example, an e-mail in HTML format may hold the URL of a website of a well-known enterprise, but in reality, the link connects to a fake website.The key to successfully use a URL similar to that of the intended website is to trick the visual senses. For example, the sender’s address could be disguised as that of Nikkei BP, and the link set to http://www.nikeibp.co.jp/ which has one k less than the correct URL which is http://www.nikkeibp.co.jp/. The two URLs look very similar, and the difference barely noticeable. Hence people are easily tricked into clicking the link.Besides the above, there are many more scams that exploit the trickery of visual senses. Therefore, you should not easily trust the given sender’s name and a website’s appearance. Never click on unfamiliar and suspicious URLs on a webpage. Also, never enter personal information into a website without careful scrutiny.3. ConclusionsBusiness strategy is the most effective form of defense and also the easiest to carry out. Therefore, they should be the first line of defense, and not last. First, determine if instant messaging is essential in the business; then weigh its pros and cons. Rules and norms must be set on user ends if it is decided that the business cannot do without instant messaging functionality. The end server should be able to support functions like centralized logging and encryption. If not, then strict rules must be drawn, and carried out by the users. Especially, business discussions must not be done over an instant messenger.The paper categorized hacking tricks into three categories: (1) Trojan programs that share files via instant messenger. (2) Phishing (3) Fake Websites. Hacking tricks when successfully carried out could cause considerable loss and damage to users. The first category of hacking tricks can be divided into three types: (1) Hijacking and Impersonation; (2) Denial of Service; (3) Information Disclosure.Acknowledgement:This work was supported by the National Science Council, Taiwan, under contract No. NSC 95-2221-E-029-024.References[1] B. Schneier, “The trojan horse race,”Communications of ACM, Vol. 42, 1999, pp.128.[2] C. L. Schuba, “Analysis of a denial of serviceattack on TCP,” IEEE Security and PrivacyConference, 1997, pp. 208-223.[3] E. Schultz, “Phishing is becoming moresophisticated,” Computer and Security, Vol.24(3), 2005, pp. 184-185.[4]G. Miklau, D. Suciu, “A formal analysis ofinformation disclosure in data exchange,”International Conference on Management ofData, 2004, pp. 575-586.[5]J. Hoyle, “'Phishing' for trouble,” Journal ofthe American Detal Association, Vol. 134(9),2003, pp. 1182-1182.[6]J. Scambray, S. McClure, G. Kurtz, Hackingexposed: network security secrets and solutions,McGraw-Hill, 2001.[7]T. Tsuji and A. Shimizu, “An impersonationattack on one-time password authenticationprotocol OSPA,” to appear in IEICE Trans.Commun, Vol. E86-B, No.7, 2003.[8]Anti-Phishing Working Group,.[9]/region/tw/enterprise/article/icq_threat.html.有关网络环境安全的黑客技术摘要：现在人们往往通过互联网处理事务。
毕业设计外文文献翻译【范本模板】
毕业设计（论文)外文资料翻译系别：专业：班级:姓名：学号:外文出处:附件： 1. 原文; 2。
译文2013年03月附件一：A Rapidly Deployable Manipulator SystemChristiaan J。
J。
Paredis, H. Benjamin Brown，Pradeep K. KhoslaAbstract:A rapidly deployable manipulator system combines the flexibility of reconfigurable modular hardware with modular programming tools，allowing the user to rapidly create a manipulator which is custom-tailored for a given task. This article describes two main aspects of such a system，namely，the Reconfigurable Modular Manipulator System （RMMS)hardware and the corresponding control software。
1 IntroductionRobot manipulators can be easily reprogrammed to perform different tasks, yet the range of tasks that can be performed by a manipulator is limited by mechanicalstructure。
Forexample，a manipulator well-suited for precise movement across the top of a table would probably no be capable of lifting heavy objects in the vertical direction. Therefore，to perform a given task,one needs to choose a manipulator with an appropriate mechanical structure.We propose the concept of a rapidly deployable manipulator system to address the above mentioned shortcomings of fixed configuration manipulators。
本科毕业设计外文翻译
Section 3 Design philosophy, design method andearth pressures3.1 Design philosophy3.1.1 GeneralThe design of earth retaining structures requires consideration of the interaction between the ground and the structure. It requires the performance of two sets of calculations:1）a set of equilibrium calculations to determine the overall proportions and the geometry of the structure necessary to achieve equilibrium under the relevant earth pressures and forces;2）structural design calculations to determine the size and properties of thestructural sections necessary to resist the bending moments and shear forces determined from the equilibrium calculations.Both sets of calculations are carried out for specific design situations (see 3.2.2) in accordance with the principles of limit state design. The selected design situations should be sufficientlySevere and varied so as to encompass all reasonable conditions which can be foreseen during the period of construction and the life of the retaining wall.3.1.2 Limit state designThis code of practice adopts the philosophy of limit state design. This philosophy does not impose upon the designer any special requirements as to the manner in which the safety and stability of the retaining wall may be achieved, whether by overall factors of safety, or partial factors of safety, or by other measures. Limit states (see 1.3.13) are classified into:a) ultimate limit states (see 3.1.3);b) serviceability limit states (see 3.1.4).Typical ultimate limit states are depicted in figure 3. Rupture states which are reached before collapse occurs are, for simplicity, also classified andtreated as ultimate limit states. Ultimate limit states include:a) instability of the structure or any hart of it, including supports and foundations, considered as a rigid body;b) failure by rupture of the structure or any part of it, including supports and foundations.3.1.3 Ultimate limit states3.1.3.1 GeneralThe following ultimate limit states should be considered. Failure of a retaining wall as a result of:a) instability of the earth mass, e.g. a slip failure, overturning or a rotational failure where the disturbing moments on the structure exceed the restoring moments, a translational failure where the disturbing forces (see 1.3.8) exceed the restoring forces and a bearing failure. Instability of the earth mass aim-involving a slip failure ，may occur where:1)the wall is built on sloping ground which itself is close to limiting equilibrium; or2) the structure is underlain by a significant depth of clay whose undrained strength increases only gradually with depth; or3) the structure is founded on a relatively strong stratum underlain by weaker strata; or4) the structure is underlain by strata within which high pore water pressures may develop from natural or artificial sources.b) failure of structural members including the wall itself in bending or shear;c) excessive deformation of the wall or ground such that adjacent structures or services reach their ultimate limit state.3.1.3.2 analysis methodWhere the mode of failure involves a slip failure the methods of analysis, for stability of slopes, are described in BS 6031 and in BS 8081. Where the mode of failure involves a bearing capacity failure, the calculations should establish an effective width of foundation. The bearing pressures as determined from 4.2.2 should not exceed the ultimate bearing capacity in accordance with BS 8004.Where the mode of failure is by translational movement, with passive resistance excluded, stable equilibrium should be achieved using the design shear strength of the soil in contact with the base of the earth retaining structure.Where the mode of failure involves a rotational or translational movement, the stable equilibrium of the earth retaining structure depends on the mobilization of shear stresses within the soil. The full mobilization of the soil shear strength gives rise to limiting active and passive thrusts. Theselimiting thrusts act in concert on the structure only at the point of collapse, i.e. ultimate limit state.3.1.4 Serviceability limit statesThe following serviceability limit states should be considered:a) substantial deformation of the structure;b) substantial movement of the ground.The soil deformations, which accompany the full mobilization of shear strength in the surrounding soil, are large in comparison with the normally acceptable strains in service. Accordingly, for most earth retaining structures the serviceability limit state of displacement will be the governing criterion for a satisfactory equilibrium and not the ultimate limit state of overall stability. However, although it is generally impossible or impractical to calculate displacements directly, serviceability can be sufficiently assured by limiting the proportion of available strength actually mobilized in service; by the method given in 3.2.4 and 3.2.5.The design earth pressures used for serviceability limit state calculations will differ from those used for ultimate limit state calculations only where structures are to be subjected to differing design values of external loads (generally surcharge and live loads) for the ultimate limit state and for the serviceability limit state.3.1.5 Limit states and compatibility of deformationsThe deformation of an earth retaining structure is important because it has a direct effect upon the forces on the structure, the forces from the retained soil and the forces which result when the structure moves against the soil. The structural forces and bending moments due to earth pressures reduce as deformation of the structure increases.The maximum earth pressures on a retaining structure occur during workingconditions and the necessary equilibrium calculations (see 3.2.1) are based on the assumption that earth pressures greater than fully active pressure (see 1.3.11) and less than fully passive will act on the retaining structure during service. As ultimate limit state with respect to soil pressures is approached, with sufficient deformation of the structure, the active earth pressure (see 1.3.1) in the retained soil reduces to the fully active pressure and the passive resistance (see 1.3.15) tends to increase to the full available passive resistance (see 1.3.12).The compatibility of deformation of the structure and the corresponding earth pressures is important where the form of structure, for example a propped cantilever wall, prevents the occurrence of fully active pressure at the prop. It is alsoparticularly important where the structure behaves as a brittle material and loses strength as deformation increases, such as an unreinforced mass gravity structure or where the soil is liable to strain softening as deformation increases.3.1.6 Design values of parametersThese are applicable at the specified limit states in the specified design situations. All elements of safety and uncertainty should be incorporated into the design values.The selection of design values for soil parametersshould take account of:a) the possibility of unfavorable variations in the values of the parameters;b) the independence or interdependence of the various parameters involved in the calculation;c) the quality of workmanship and level of control specified for the construction.3.1.7 Applied loadsThe design value for the density of fill materials, should be a pessimistic or unfavorable assessment of actual density.For surcharges and live loadings different values may be appropriate for the differing conditions of serviceability and ultimate limit states and for different load combinations. The intention of this code of practice is to determine those earthpressures which will not be exceeded in a limit state, if external loads are correctly predicted. External loads, such as structural dead loads or vehicle surcharge loads may be specified in other codes as nominal or characteristic values. Some of the structural codes, with which this code interfaces, specify different load factors to be applied for serviceability or ultimate limit state the checks and for different load combinations,See 3.2.7 .Design values of loads, derived by factoring or otherwise, are intended, here, to behere most pessimistic or unfavorable loads which should he used in the calculations for the structure. Similarly, when external loads act on the active or retained side of the wall these same external loads should be derived in the same way. The soil is then treated as forming part of the whole structural system.3.1.8 Design soil strength (see 1.3.4)Assessment of the design values depends on the required or anticipated life of the structure, but account should be taken also of the short-term conditions which apply during and immediately following the period of construction. Single design values of soil strength should be obtained from a consideration of the representative values for peak and ultimate strength. The value so selected will satisfy, simultaneously, the considerations of ultimate and serviceability limit states. The design value should be the lower of:a) that value of soil strength, on the stress-strain relation leading to peak strength,which is mobilized at soil strains acceptable forserviceability. This can be expressed as the peak strength reduced by a mobilization factor M as given in 3.2.4 or 3.2.5; orb) that value which would be mobilized at collapse, after significant ground movements. This can general be taken t.o be the critical state strength. Design values selected in this way should be checked to ensure that they conform to 3.1.6. Design values should not exceed representative values of the fully softened critical state soil strength.3.1.9 Design earth pressuresThe design values of lateral earth pressure are intended to give an overestimate of the earth pressure on the active or retained side and an underestimate of the earth resistance on the passive side for small deformations of the structure as a whole, in the working state. Earth pressures reduce as fully active conditions are mobilized atpeak soil strength in the retained soil, under deformations larger than can be tolerated for serviceability. As collapse threatens, the retained soil approaches a critical state, in which its strength reduces to that of loose material and the earth pressures consequently tend to increase once more to active values based on critical state strength.The initial presumption should be that the design earth pressure will correspond to that arising from the design soil strength, see 3.1.8. But the mobilized earth pressure in service, for some walls, will exceed these values. This enhanced earth pressure will control the design, for example.a) Where clays may swell in the retained soil zone, or be subject to the effects of compaction in layers, larger earth pressures may occur in that zone, causing corresponding resistance from the ground, propping forces, or anchor tensions to increase so as t.o maintain overall equilibrium.b) Where clays may have lateral earth pressures in excess of the assessed values taking account of earth pressures prior to construction and the effects of wall installation and soil excavation or filling, the earth pressure inretained soil zones will be increased to maintain overall equilibrium.c) Where both the wall and backfill are placed on compressible soils, differential settlement due to consolidation may lead to rotation of the wall into the backfill. This increases the earth pressures in the retained zone.d) Where the structure is particularly stiff, for example fully piled box-shapedBridge abutments, higher earth pressures, caused, for example by compaction, may be preserved, notwithstanding that the degree of wall displacement or flexibility required to reduce retained earth pressures to their fully active values in cohesionless materials is only of the order of a rotation of 10-3 radians.In each of these cases, mobilized soil strengths will increase as deformations continue, so the unfavorable earth pressure conditions dill not persist as collapse approaches.The design earth pressures are derived from design soil strengths using the usual methods of plastic analysis, with earth pressure coefficients (see 1.3.9) given in this code of practice being based on Kerisel&Absi(1990). The same design earth pressures are used in the default condition for the design of structural. sections, see 3.2.7.3.2 Design method3.2.1 Equilibrium calculationsIn order to determine the geometry of the retaining wall, for exampal the depth of penetration of an embedded wall (see 1.3.10), equilibrium calculations should be carried out for care formulated design situations. The design fully calculations relate to a free-body diagram of forces and stresses for the whole retaining wall. The design calculations should demonstrate that there is global equilibrium of vertical and horizontal forces, and of moments. Separate calculations should be made for different design situations.The structural geometry of the retaining wall and the equilibrium calculations should be determined from the design earth pressures derived from the design soil strength using the appropriate earth pressure coefficients.Design earth pressures will lead to active and passive pressure diagrams of the type shown in figure 4. The earth pressure distribution should be checked for global equilibrium of the structure. Horizontal forces equilibrium and momentequilibrium will give the prop force in figure 4a and the location of the pointof reversed stress conditions near the toe in figure 4b. Vertical forces equilibrium should also be checked.3.2.2 Design situations3.2.2.1 GeneralThe specification of design situations should include the disposition and classification of the various zones of soil and rock and the elements of construction which could be involved in a limit state event. The specification of design situations should follow a consideration of all uncertainties and the risk factors involved, including thefollowing:a) the loads and their combinations, e.g. surcharge and%or external loads on the active or retained side of the wall;b) the geometry of the structure, and the neighbouring soil bodies, representing the worst credible conditions, for example over-excavation during or after construction;c) the material characteristics of the structure, e.g. following corrosion;d) effects due to the environment within which the design is set, such as: -ground water levels, including their variations due to the effects of dewateringpossible flooding or failure of any drainage system;-scour, erosion and excavation, leading to changes in the geometry of the groundsurface;-chemical corrosion;-weathering;-freezing;-the presence of gases emerging from the ground;-other effects of time and environment on thestrength and other properties of materials;e) earthquakes;f) subsidence due to mining or other causes;g) the tolerance of the structure to deformations;h) the effect of the new structure on existing structures or services and the effect of existing structures or services on the new structure;i) for structures resting on or near rock, theconsideration of:-interbedded hard and soft strata;-faults, joints and fissures;-solution cavities such as swallow holes or fissures, filled with soft material, and continuing solution processes.3.2.2.2 Minimum surcharge and minimum unplanned excavationIn checking the stable equilibrium and soil deformation all walls should be designed for a minimum design surcharge loading of 10 kN/m2 and a minimum depth of excavation in front of the wall, which should be:a)not less than 0.5 m; andb)not less than10% of the total height retained for cantilever walls, or the height retained lowest support level for propped or anchored walls. These minimum values should be reviewed for each design and more adverse values adopted in particularly critical or uncertain circumstances. The requirement for an additional or unplanned excavation as a design criterion is to provide for unforeseen and accidental events. Foreseeable excavations suet as service or drainage trenches infront of a retaining wall, which may be required at some stage in the life of the structure, should be treated as a planned excavation. Actual excavation beyond the planned depth is outside the design considerations of this code.3.2.2.3 Water pressure regimeThe water pressure regime used in the design should be the most onerous that is considered to be reasonably possible.3.2.3 Calculations based on total and effective stress parameters The changes in loading associated with the construction of a retaining wall may result in changes in the strength of the ground in the vicinity of the wall. if"here the mass permeability of the ground is low these changes of strength take place over some time and therefore the design should consider conditions in both the short- and long-term. Which condition will be critical depends on whether the changes in load applied to the soil mass cause an increase or decrease in soil strength. The long-term condition is likely to be critical where the soil mass undergoes a net reduction in load as a result of excavation, such as adjacent to a cantilever wall. Conversely where the soil mass is subject to a net increase in loading, such as beneath the foundation of a gravity or reinforced stem wall at ground level, the short-term condition is likely to be critical for stability. When considering long-term earth pressures and equilibrium, allowance should be made for changes in ground water conditions and pore water pressure regime which may result from the construction of the works or from other agencies.Calculations for long-term conditions require shear strength parameters to be in terms of effective stress and should take account of a range of water pressures based on considerations of possible seepage flow conditions within the earth mass. Effective stress methods can also be used to assess the short-term conditions provided the pore water pressures developed during construction areknown. A total stress method of analysis may be used to assess the short-term conditions in clays and soils of low permeability, but an inherent assumption of this method is that there will be no change in the soil strength as a result of the changes in load caused by the construction. For granular materials and soils of high permeability all excess pore water pressure will dissipate rapidly so that the relevant strength is always the drained strength and the earth pressures and equilibrium calculations are always in terms of effectivestresses.3.2.4 Design using total stress parametersThe retaining wall should be designed to be in equilibrium design clay when based on a mobilized undrained strength (design cu) which does not exceed the representativedivided by a mobilization undrained strength factor M. The value of M should not be less than 1.5 if wall displacements are required to be less than 0.5 % of wall height.The value of M should be larger than 1.5 for clays which require large strains to mobilize their peak strength.3.2.5 Design using effective stress parametersThe retaining wall should be designed to be in equilibrium mobilizing a soil strength the lesser or:a) the representative peak strength of the soil divided by a factor M=1.2: that is:Mmax tantiverepresenta design tan ϕϕ'='（3）Mcc' ='tive representadesign （4） orb) the representative critical state strength of the soil.This will ensure that for soils which are medium dense or firm the wall displacements in service will be limited to 0.5 % of the wall height. The mobilization factor of 1.2 should be used in conjunction with the front of the wall, the 'unplanned' excavation inminimum surcharge loading and the water pressure regime, see 3.2.2.2 and 3.2.2.3.A more detailed analysis of displacement should be are to be applied or for soft or loose soils. The criteria a) and b), taken together, should provide a sufficient reserve of safety against small unforeseen loads and adverse conditions.In stiff clays subject to cycles of strain, such as through seasonal variation of pore water pressure, the long-term peak strength may deteriorate to the critical state strength. The requirements of a) and b) above are sufficiently cautious to accommodate this possibility.3.2.6 Design values of wall friction, base friction and undrained wall adhesionThese should be derived from the representative strength determined in accordance with 2.2.8,using the same mobilization actors as for the adjacent soil.The design value of the friction or adhesion mobilized at an interface with the structure be the lesser of:a) the representative value determined by described in 2.2.8 if such test results are available; orb) 75% of the design shear strength to be mobilized in the soil itself, that is using:ϕδ'⨯= design tan 75.0 design tan(5)u w design 75.0design c c ⨯=(6)Since for the soil mass: 1.2tan tive representa design tan ϕϕ'=' (7)this is equivalent to:32 tive representa design ≈'ϕδ (8)similarly, in total stress analysis:5.1 ng after taki ,5.0 tive representa design uw ==M c c (9) The friction or adhesion, which can be mobilized in practice, is generally less than the value deduced on the basis of soil sliding against the relevant surface. It is unlikely for example, that a cantilever wall will remain at constant elevation while the active soil zone subsides creating full downward wall friction on the retained side, and the passive zone heaves creating full upward wall friction on the excavated side. It is more likely that the wall would move vertically with one or other soil zone,reducing friction on that side, and thereby attaining vertical force equilibrium. The 25% reduction in the design shear strength in b) above makes an allowance for this possibility. Further reductions, and even the elimination of wall friction or its reversal, may be necessary when soil structure interaction is taken into account. Wall friction on the retained or active side should be excluded when the wall is capable of penetrating deeper, due to the vertical thrust imparted by inclined anchors on an embedded wall, by structural loads on a basement wall, or where a clay soil may heave due to swelling during outward movement of the wall. Wall friction on the passive side should be excluded when the wall is prevented from sinking but the adjacent soil may fail to heave, due for example to settlement of loose granular soils induced by cyclic loads, or when the wall is free to move upwards with the passive soil zone, as may happen with buried anchor blocks.3.2.7 Design to structural codesThe earth pressures to be used in structural design calculations are the most severe earth pressures determined for serviceability limit state, see 3.1.9. These are the most severe that can credibly occur under the design situations, see 3.2.2. Accordingly the application of partial load factors to the bending moments and internal forces derived from these earth pressures, is not normally required. Hacking determined the earth pressures using design thestructure increases it should be assumed that loads and design soil strengths, the structural load affects (bending moments, and shears) can be calculated using equilibrium principles in the usual way without applying any further factors. Finally, the material properties and sections should be derived from the load effects according to the structural codes. Reference should be made to the documentary source for the loadings, such as BS 5400:Part 4 for guidance on the respective design values.Structural design calculations based upon ultimate limit state assume that the moments and forces applicable at ultimate larger than limit state are significantly at serviceability limit state. BS8110: Part 1 and Part; BS 5400:Part 4 and BS 5950:Part 1 and Part 5 make this assumption. At ultimate limit state, the earth active or retained side are not pressures on the a maximum.Because the structural forces and bending moments due to earth pressures reduce as deformation of the most severe earth pressures, which are usually determined for the serviceability limit state, also apply to the ultimate limit state structural design calculations. The design at serviceability limit state for flexible structures such as steel or reinforced and prestressed undertaken in a like concrete may be manner to the analysis in 3.1 to 3.4 of BS 8110:Part 2:1985.For gravity mass walls such as masonry structures, which are relatively rigid, the earth pressures on the retained or active side are likely to be higher than the fully active values in the working state. The earth pressures at serviceability and ultimate limit states will be similar, because the displacement criteria will be similar.3.3 Disturbing forces3.3.1 GeneralThe disturbing forces to be taken into account in the equilibrium calculations are the earth pressures on the active or retained side of the wall, togetherwith loads due to the compaction of the fill (if any) behind the wall, surcharge loads, external loads and last, but by no means least, the water pressure.3.3.2 At-rest earth pressuresThe earth pressures which act on retaining walls, or parts of retaining walls, below existing ground, depend on the initial or at-rest state of stress in the ground. For an undisturbed soil at a state of rest, the ratio of the horizontal to vertical stress depends on the type of soil, its geological origin, the temporary loads which may have acted on the surface of the soil and the topography.Soil suction and empirical correlations with in situ tests including static cone and dilatometer. The value of K i depends on the type of soil, its geological history, the loads which may have topography, the temporary acted on the ground surface and changes in ground strain or ground water regime due to natural or artificial causes.Where there has been no lateral strain within the ground, K i can be determinable from equated with K0the coefficient one-dimensional consolidation and swelling tests conducted in a stress-path triaxial test using appropriate stress cycles. For normally consolidated soils, both granular and cohesive: ϕ'1K=sin-(10)For overconsolidated soils, K0 is larger and may approach the passive value at shallow depths in a heavily overconsolidated clay, (see for example Lambe and Whitman, quoting Hendron and Wroth 1975).K i is not used directly in earth retaining structure design because the construction process always modifies this initial value. The value of K i is however, important in assessing the degree of deformation which will be induced as the earth pressure tends towards active or passive states. In normally consolidated soil the ground deformation necessary to mobilize the active condition will be small in relation to that required to mobilize thefull passive resistance, while in heavily overconsolidated soil the required ground deformation will be of similar magnitude.Additional ground deformation is necessary for the structure to approach a failure condition with the earth pressures moving further towards their limiting active and passive values.Where a stressed support system is employed (e.g.ground anchorage) then the partial mobilization the active state on the retained side is reversed during installation of the system and,in the zone of support, the effective stress ratio in the soil may pass through the original toward the value of K0，and tend toward the value of K p.3.3.3 Active earth pressures3.3.3.1 GeneralActive earth pressures are generally assumed to increase linearly with increasing depth. However there may be variations from a linear relationship as a consequence, for example, of wall flexure. This can result in reduced bending moments in the structure, where the structure is flexible.Where deformations of the retaining structure are caused by transient loads, as encountered in highway structures, locked-in moments may remain after the load has been removed. These locked-in stresses will accumulate under repeated loading. This effect will limit the application of reduced bending moments in such structures.The design soil strength, derived in accordance with 3.1.8 should be used in evaluating the active earth pressure.3.3.3.2 Cohesionless soilThe basic formula for active pressure is applicable in the following simple situation:- uniform cohesionless soil;- no water pressure;- mode of deformation such that earth pressure increases linearly with。
外文文献翻译范例
StatusComplete
Type：Office
Location：Hong Kong
Construction started：18 April 1985
Completed：1990
Opening：17 May 1990
HeightAntenna spire：367.4 m (1,205.4 ft)
2011年6月8日
外文文献翻译（译成中文1000字左右）：
【主要阅读文献不少于5篇，译文后附注文献信息，包括：作者、书名（或论文题目）、出 版 社（或刊物名称）、出版时间（或刊号）、页码。提供所译外文资料附件（印刷类含封面、封底、目录、翻译部分的复印件等，网站类的请附网址及原文）
原文网址：/TALLEST_TOWERS/t_sears.htm
译文
建筑师：Bruce Graham, design partner, Skidmore, Owings and Merrill
地点：Chicago
甲方：Sears Roebuck and Company
工程师：Fazlur Khan of Skidmore, Owings and Merrill.项目年份：2008
香港1985年4月18日开工建设1990年完成1990年5月17日开幕高度天线尖顶三百六十七点四米2418英尺屋顶三百一十五点米10335英尺顶层二百八十八点二米九百四十五点五英尺技术细节地上楼层数724层楼建筑面积一十三点五万平方米1450000平方英尺电梯数45由奥的斯电梯公司生产的设计与施工主要承建商香港建设控股有限公司引文需要熊谷组香港贝聿铭建筑师事务所建筑师事务所谢尔曼西贡有限公司sl的托马斯博阿达莱斯利罗伯逊结构工程师协会rllp参考文献对中国塔简称中银大厦银行是中环香港最知名的摩天大楼之一
毕业设计外文翻译例文
大连科技学院毕业设计(论文)外文翻译学生姓名专业班级指导教师职称所在单位教研室主任完成日期 2016年4月15日Translation EquivalenceDespite the fact that the world is becoming a global village, translation remains a major way for languages and cultures to interact and influence each other. And name translation, especially government name translation, occupies a quite significant place in international exchange.Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. While interpreting—the facilitating of oral or sign-language communication between users of different languages—antedates writing, translation began only after the appearance of written literature. There exist partial translations of the Sumerian Epic of Gilgamesh (ca. 2000 BCE) into Southwest Asian languages of the second millennium BCE. Translators always risk inappropriate spill-over of source-language idiom and usage into the target-language translation. On the other hand, spill-overs have imported useful source-language calques and loanwords that have enriched the target languages. Indeed, translators have helped substantially to shape the languages into which they have translated. Due to the demands of business documentation consequent to the Industrial Revolution that began in the mid-18th century, some translation specialties have become formalized, with dedicated schools and professional associations. Because of the laboriousness of translation, since the 1940s engineers have sought to automate translation (machine translation) or to mechanically aid the human translator (computer-assisted translation). The rise of the Internet has fostered a world-wide market for translation services and has facilitated language localizationIt is generally accepted that translation, not as a separate entity, blooms into flower under such circumstances like culture, societal functions, politics and power relations. Nowadays, the field of translation studies is immersed with abundantly diversified translation standards, with no exception that some of them are presented by renowned figures and are rather authoritative. In the translation practice, however, how should we select the so-called translation standards to serve as our guidelines in the translation process and how should we adopt the translation standards to evaluate a translation product?In the macro - context of flourish of linguistic theories, theorists in the translation circle, keep to the golden law of the principle of equivalence. The theory of Translation Equivalence is the central issue in western translation theories. And the presentation of this theory gives great impetus to the development and improvement of translation theory. It‟s not diffi cult for us to discover that it is the theory of Translation Equivalence that serves as guidelines in government name translation in China. Name translation, as defined, is the replacement of thename in the source language by an equivalent name or other words in the target language. Translating Chinese government names into English, similarly, is replacing the Chinese government name with an equivalent in English.Metaphorically speaking, translation is often described as a moving trajectory going from A to B along a path or a container to carry something across from A to B. This view is commonly held by both translation practitioners and theorists in the West. In this view, they do not expect that this trajectory or something will change its identity as it moves or as it is carried. In China, to translate is also understood by many people normally as “to translate the whole text sentence by sentence and paragraph by paragraph, without any omission, addition, or other changes. In both views, the source text and the target text must be “the same”. This helps explain the etymological source for the term “translation equivalence”. It is in essence a word which describes the relationship between the ST and the TT.Equivalence means the state or fact or property of being equivalent. It is widely used in several scientific fields such as chemistry and mathematics. Therefore, it comes to have a strong scientific meaning that is rather absolute and concise. Influenced by this, translation equivalence also comes to have an absolute denotation though it was first applied in translation study as a general word. From a linguistic point of view, it can be divided into three sub-types, i.e., formal equivalence, semantic equivalence, and pragmatic equivalence. In actual translation, it frequently happens that they cannot be obtained at the same time, thus forming a kind of relative translation equivalence in terms of quality. In terms of quantity, sometimes the ST and TT are not equivalent too. Absolute translation equivalence both in quality and quantity, even though obtainable, is limited to a few cases.The following is a brief discussion of translation equivalence study conducted by three influential western scholars, Eugene Nida, Andrew Chesterman and Peter Newmark. It‟s expected that their studies can instruct GNT study in China and provide translators with insightful methods.Nida‟s definition of translation is: “Translation consists in reproducing in the receptor language the closest natural equivalent of the source language message, first in terms of meaning and secondly in terms of style.” It i s a replacement of textual material in one language〔SL〕by equivalent textual material in another language（TL）. The translator must strive for equivalence rather than identity. In a sense, this is just another way of emphasizing the reproducing of the message rather than the conservation of the form of the utterance. The message in the receptor language should match as closely as possible the different elements in the source language to reproduce as literally and meaningfully as possible the form and content of the original. Translation equivalence is an empirical phenomenon discovered bycomparing SL and TL texts and it‟s a useful operational concept like the term “unit of translati on”.Nida argues that there are two different types of equivalence, namely formal equivalence and dynamic equivalence. Formal correspondence focuses attention on the message itself, in both form and content, whereas dynamic equivalence is based upon “the principle of equivalent effect”.Formal correspondence consists of a TL item which represents the closest equivalent of a ST word or phrase. Nida and Taber make it clear that there are not always formal equivalents between language pairs. Therefore, formal equivalents should be used wherever possible if the translation aims at achieving formal rather than dynamic equivalence. The use of formal equivalents might at times have serious implications in the TT since the translation will not be easily understood by the target readership. According to Nida and Taber, formal correspondence distorts the grammatical and stylistic patterns of the receptor language, and hence distorts the message, so as to cause the receptor to misunderstand or to labor unduly hard.Dyn amic equivalence is based on what Nida calls “the principle of equivalent effect” where the relationship between receptor and message should be substantially the same as that which existed between the original receptors and the message. The message has to be modified to the receptor‟s linguistic needs and cultural expectation and aims at complete naturalness of expression. Naturalness is a key requirement for Nida. He defines the goal of dynamic equivalence as seeking the closest natural equivalent to the SL message. This receptor-oriented approach considers adaptations of grammar, of lexicon and of cultural references to be essential in order to achieve naturalness; the TL should not show interference from the SL, and the …foreignness …of the ST setting is minimized.Nida is in favor of the application of dynamic equivalence, as a more effective translation procedure. Thus, the product of the translation process, that is the text in the TL, must have the same impact on the different readers it was addressing. Only in Nida and Taber's edition is it clearly stated that dynamic equivalence in translation is far more than mere correct communication of information.As Andrew Chesterman points out in his recent book Memes of Translation, equivalence is one of the five element of translation theory, standing shoulder to shoulder with source-target, untranslatability, free-vs-literal, All-writing-is-translating in importance. Pragmatically speaking, observed Chesterman, “the only true examples of equivalence (i.e., absolute equivalence) are those in which an ST item X is invariably translated into a given TL as Y, and vice versa. Typical examples would be words denoting numbers (with the exceptionof contexts in which they have culture-bound connotations, such as “magic” or “unlucky”), certain technical terms (oxygen, molecule) and the like. From this point of view, the only true test of equivalence would be invariable back-translation. This, of course, is unlikely to occur except in the case of a small set of lexical items, or perhaps simple isolated syntactic structure”.Peter Newmark. Departing from Nida‟s receptor-oriented line, Newmark argues that the success of equivalent effect is “illusory “and that the conflict of loyalties and the gap between emphasis on source and target language will always remain as the overriding problem in translation theory and practice. He suggests narrowing the gap by replacing the old terms with those of semantic and communicative translation. The former attempts to render, as closely as the semantic and syntactic structures of the second language allow, the exact contextual meaning of the original, while the latter “attempts to produce on its readers an effect as close as possible to that obtained on the readers of the original.” Newmark‟s description of communicative translation resembles Nida‟s dynamic equivalence in the effect it is trying to create on the TT reader, while semantic translation has similarities to Nida‟s formal equivalence.Meanwhile, Newmark points out that only by combining both semantic and communicative translation can we achieve the goal of keeping the …spirit‟ of the original. Semantic translation requires the translator retain the aesthetic value of the original, trying his best to keep the linguistic feature and characteristic style of the author. According to semantic translation, the translator should always retain the semantic and syntactic structures of the original. Deletion and abridgement lead to distortion of the author‟s intention and his writing style.翻译对等尽管全世界正在渐渐成为一个地球村，但翻译仍然是语言和和文化之间的交流互动和相互影响的主要方式之一。
毕业设计(论文)外文资料及译文(模板)
大连东软信息学院
毕业设计（论文）外文资料及译文
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大连东软信息学院
Dalian Neusoft University of Information
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大连东软信息学院毕业设计（论文）译文
大连东软信息学院毕业设计（论文）译文
大连东软信息学院毕业设计（论文）译文
大连东软信息学院毕业设计（论文）译文
大连东软信息学院毕业设计（论文）译文。
本科毕业设计外文文献及译文1
本科毕业设计外文文献及译文文献、资料题目：Transit Route Network Design Problem:Review文献、资料来源：网络文献、资料发表（出版）日期：2007.1院（部）：xxx专业：xxx班级：xxx姓名：xxx学号：xxx指导教师：xxx翻译日期：xxx外文文献：Transit Route Network Design Problem:Review Abstract:Efficient design of public transportation networks has attracted much interest in the transport literature and practice,with manymodels and approaches for formulating the associated transit route network design problem _TRNDP_having been developed.The presentpaper systematically presents and reviews research on the TRNDP based on the three distinctive parts of the TRNDP setup:designobjectives,operating environment parameters and solution approach.IntroductionPublic transportation is largely considered as a viable option for sustainable transportation in urban areas,offering advantages such as mobility enhancement,traffic congestion and air pollution reduction,and energy conservation while still preserving social equity considerations. Nevertheless,in the past decades,factors such as socioeconomic growth,the need for personalized mobility,the increase in private vehicle ownership and urban sprawl have led to a shift towards private vehicles and a decrease in public transportation’s share in daily commuting (Sinha2003;TRB2001;EMTA2004;ECMT2002;Pucher et al.2007).Efforts for encouraging public transportation use focuses on improving provided services such as line capacity,service frequency,coverage,reliability,comfort and service quality which are among the most important parameters for an efficient public transportation system(Sinha2003;Vuchic2004.) In this context,planning and designing a cost and service efficientpublic transportation network is necessary for improving its competitiveness and market share. The problem that formally describes the design of such a public transportation network is referred to as the transit route network design problem(TRNDP);it focuses on the optimization of a number of objectives representing the efficiency of public transportation networks under operational and resource constraints such as the number and length of public transportation routes, allowable service frequencies,and number of available buses(Chakroborty2003;Fan and Machemehl2006a,b).The practical importance of designing public transportation networks has attractedconsiderable interest in the research community which has developed a variety of approaches and modelsfor the TRNDP including different levels of design detail and complexity as well as interesting algorithmic innovations.In thispaper we offer a structured review of approaches for the TRNDP;researchers will obtain a basis for evaluating existing research and identifying future research paths for further improving TRNDP models.Moreover,practitioners will acquire a detailed presentation of both the process and potential tools for automating the design of public transportation networks,their characteristics,capabilities,and strengths.Design of Public Transportation NetworksNetwork design is an important part of the public transportation operational planning process_Ceder2001_.It includes the design of route layouts and the determination of associated operational characteristics such as frequencies,rolling stock types,and so on As noted by Ceder and Wilson_1986_,network design elements are part of the overall operational planning process for public transportation networks;the process includes five steps:_1_design of routes;_2_ setting frequencies;_3_developing timetables;_4_scheduling buses;and_5_scheduling drivers. Route layout design is guided by passenger flows:routes are established to provide direct or indirect connection between locations and areas that generate and attract demand for transit travel, such as residential and activity related centers_Levinson1992_.For example,passenger flows between a central business district_CBD_and suburbs dictate the design of radial routes while demand for trips between different neighborhoods may lead to the selection of a circular route connecting them.Anticipated service coverage,transfers,desirable route shapes,and available resources usually determine the structure of the route network.Route shapes areusually constrained by their length and directness_route directness implies that route shapes are as straight as possible between connected points_,the usage of given roads,and the overlapping with other transit routes.The desirable outcome is a set of routesconnecting locations within a service area,conforming to given design criteria.For each route, frequencies and bus types are the operational characteristics typically determined through design. Calculations are based on expected passenger volumes along routes that are estimated empirically or by applying transit assignmenttechniques,under frequency requirement constraints_minimum and maximum allowedfrequencies guaranteeing safety and tolerable waiting times,respectively_,desired load factors, fleet size,and availability.These steps as well as the overall design.process have been largely based upon practical guidelines,the expert judgment of transit planners,and operators experience_Baaj and Mahmassani1991_.Two handbooks by Black _1995_and Vuchic_2004_outline frameworks to be followed by planners when designing a public transportation network that include:_1_establishing the objectives for the network;_2_ defining the operational environment of the network_road structure,demand patterns,and characteristics_;_3_developing;and_4_evaluating alternative public transportation networks.Despite the extensive use of practical guidelines and experience for designing transit networks,researchers have argued that empirical rules may not be sufficient for designing an efficient transit network and improvements may lead to better quality and more efficient services. For example,Fan and Machemehl_2004_noted that researchers and practitioners have been realizing that systematic and integrated approaches are essential for designing economically and operationally efficient transit networks.A systematic design process implies clear and consistent steps and associated techniques for designing a public transportation network,which is the scope of the TRNDP.TRNDP:OverviewResearch has extensively examined the TRNDP since the late1960s.In1979,Newell discussed previous research on the optimal design of bus routes and Hasselström_1981_ analyzed relevant studies and identified the major features of the TRNDP as demand characteristics,objective functions,constraints,passengerbehavior,solution techniques,and computational time for solving the problem.An extensive review of existing work on transit network design was provided by Chua_1984_who reported five types of transit system planning:_1_manual;_2_marketanalysis;_3_systems analysis;_4_systems analysis with interactive graphics;and_5_ mathematical optimization approach.Axhausemm and Smith_1984_analyzed existing heuristic algorithms for formulating the TRNDP in Europe,tested them,anddiscussed their potential implementation in the United States.Ceder and Wilson_1986_reportedprior work on the TRNDP and distinguished studies into those that deal with idealized networks and to those that focus on actual routes,suggesting that the main features of the TRNDP include demand characteristics,objectivesand constraints,and solution methods.At the same period,Van Nes et al._1988_grouped TRNDP models into six categories:_1_ analytical models for relating parameters of the public transportation system;_2_models determining the links to be used for public transportation route construction;_3_models determining routes only;_4_models assigning frequencies to a set of routes;_5_two-stage models for constructing routes and then assigning frequencies;and_6_models for simultaneously determining routes and frequencies.Spacovic et al._1994_and Spacovic and Schonfeld_1994_proposed a matrix organization and classified each study according to design parameters examined,objectives anticipated,network geometry,and demand characteristics. Ceder and Israeli_1997_suggested broad categorizations for TRNDP models into passenger flow simulation and mathematical programming models.Russo_1998_adopted the same categorization and noted that mathematical programming models guarantee optimal transit network design but sacrifice the level of detail in passenger representation and design parameters, while simulation models address passenger behavior but use heuristic procedures obtaining a TRNDP solution.Ceder_2001_enhanced his earlier categorization by classifying TRNDP models into simulation,ideal network,and mathematical programming models.Finally,in a recent series of studies,Fan and Machemehl_2004,2006a,b_divided TRNDP approaches into practical approaches,analytical optimization models for idealized conditions,and metaheuristic procedures for practical problems.The TRNDP is an optimization problem where objectives are defined,its constraints are determined,and a methodology is selected and validated for obtaining an optimal solution.The TRNDP is described by the objectives of the public transportation network service to be achieved, the operational characteristics and environment under which the network will operate,and the methodological approach for obtaining the optimal network design.Based on this description of the TRNDP,we propose a three-layer structure for organizing TRNDP approaches_Objectives, Parameters,and Methodology_.Each layer includes one or more items that characterize each study.The“Objectives”layer incorporates the goals set when designing a public transportation system such as the minimization of the costs of the system or the maximization of the quality of services provided.The“Parameters”layer describes the operating environment and includes both the design variables expected to be derived for the transit network_route layouts,frequencies_as well as environmental and operational parameters affecting and constraining that network_for example,allowable frequencies,desired load factors,fleet availability,demand characteristics and patterns,and so on_.Finally,the“Methodology”layer covers the logical–mathematical framework and algorithmic tools necessary to formulate and solve the TRNDP.The proposed structure follows the basic concepts toward setting up a TRNDP:deciding upon the objectives, selecting the transit network items and characteristics to be designed,setting the necessary constraints for the operating environment,and formulating and solving the problem. TRNDP:ObjectivesPublic transportation serves a very important social role while attempting to do this at the lowest possible operating cost.Objectives for designing daily operations of a public transportation system should encompass both angles.The literature suggests that most studies actually focus on both the service and economic efficiency when designing such a system. Practical goals for the TRNDP can be briefly summarized as follows_Fielding1987;van Oudheudsen et al.1987;Black1995_:_1_user benefit maximization;_2_operator cost minimization;_3_total welfare maximization;_4_capacity maximization;_5_energy conservation—protection of the environment;and_6_individual parameter optimization.Mandl_1980_indicated that public transportation systems have different objectives to meet. He commented,“even a single objective problem is difficult to attack”_p.401_.Often,these objectives are controversial since cutbacks in operating costs may require reductions in the quality of services.Van Nes and Bovy_2000_pointed out that selected objectives influence the attractiveness and performance of a public transportation network.According to Ceder and Wilson_1986_,minimization of generalized cost or time or maximization of consumer surplus were the most common objectives selected when developing transit network design models. Berechman_1993_agreed that maximization of total welfare is the most suitable objective for designing a public transportation system while Van Nes and Bovy_2000_argued that the minimization of total user and system costs seem the most suit able and less complicatedobjective_compared to total welfare_,while profit maximization leads to nonattractive public transportation networks.As can be seen in Table1,most studies seek to optimize total welfare,which incorporates benefits to the user and to the er benefits may include travel,access and waiting cost minimization,minimization of transfers,and maximization of coverage,while benefits for the system are maximum utilization and quality of service,minimization of operating costs, maximization of profits,and minimization of the fleet size used.Most commonly,total welfare is represented by the minimization of user and system costs.Some studies address specific objectives from the user,theoperator,or the environmental perspective.Passenger convenience,the number of transfers, profit and capacity maximization,travel time minimization,and fuel consumption minimization are such objectives.These studies either attempt to simplify the complex objective functions needed to setup the TRNDP_Newell1979;Baaj and Mahmassani1991;Chakroborty and Dwivedi2002_,or investigate specific aspects of the problem,such as objectives_Delle Site and Fillipi2001_,and the solution methodology_Zhao and Zeng2006;Yu and Yang2006_.Total welfare is,in a sense,a compromise between objectives.Moreover,as reported by some researchers such as Baaj and Mahmassani_1991_,Bielli et al._2002_,Chackroborty and Dwivedi_2002_,and Chakroborty_2003_,transit network design is inherently a multiobjective problem.Multiobjective models for solving the TRNDP have been based on the calculation of indicators representing different objectives for the problem at hand,both from the user and operator perspectives,such as travel and waiting times_user_,and capacity and operating costs _operator_.In their multiobjective model for the TRNDP,Baaj and Majmassani_1991_relied on the planner’s judgment and experience for selecting the optimal public transportation network,based on a set of indicators.In contrast,Bielli et al._2002_and Chakroborty and Dwivedi_2002_,combined indicators into an overall,weighted sum value, which served as the criterion for determining the optimaltransit network.TRNDP:ParametersThere are multiple characteristics and design attributes to consider for a realistic representation of a public transportation network.These form the parameters for the TRNDP.Part of these parameters is the problem set of decision variables that define its layout and operational characteristics_frequencies,vehicle size,etc._.Another set of design parameters represent the operating environment_network structure,demand characters,and patterns_, operational strategies and rules,and available resources for the public transportation network. These form the constraints needed to formulate the TRNDP and are,a-priori fixed,decided upon or assumed.Decision VariablesMost common decision variables for the TRNDP are the routes and frequencies of the public transportation network_Table1_.Simplified early studies derived optimal route spacing between predetermined parallel or radial routes,along with optimal frequencies per route_Holroyd1967; Byrne and Vuchic1972;Byrne1975,1976;Kocur and Hendrickson1982;Vaughan1986_,while later models dealt with the development of optimal route layouts and frequency determination. Other studies,additionally,considered fares_Kocur and Hendrickson1982;Morlok and Viton 1984;Chang and Schonfeld1991;Chien and Spacovic2001_,zones_Tsao and Schonfeld1983; Chang and Schonfeld1993a_,stop locations_Black1979;Spacovic and Schonfeld1994; Spacovic et al.1994;Van Nes2003;Yu and Yang2006_and bus types_Delle Site and Filippi 2001_.Network StructureSome early studies focused on the design of systems in simplified radial_Byrne1975;Black 1979;Vaughan1986_,or rectangular grid road networks_Hurdle1973;Byrne and Vuchic1972; Tsao and Schonfeld1984_.However,most approaches since the1980s were either applied to realistic,irregular grid networks or the network structure was of no importance for the proposed model and therefore not specified at all.Demand PatternsDemand patterns describe the nature of the flows of passengers expected to be accommodated by the public transportation network and therefore dictate its structure.For example,transit trips from a number of origins_for example,stops in a neighborhood_to a single destination_such as a bus terminal in the CBD of a city_and vice-versa,are characterized as many-to-one_or one-tomany_transit demand patterns.These patterns are typically encountered in public transportation systems connecting CBDs with suburbs and imply a structure of radial orparallel routes ending at a single point;models for patterns of that type have been proposed by Byrne and Vuchic_1972_,Salzborn_1972_,Byrne_1975,1976_,Kocur and Hendrickson _1982_,Morlok and Viton_1984_,Chang and Schonfeld_1991,1993a_,Spacovic and Schonfeld_1994_,Spacovic et al._1994_,Van Nes_2003_,and Chien et al._2003_.On the other hand,many-to-many demand patterns correspond to flows between multiple origins and destinations within an urban area,suggesting that the public transportation network is expected to connect various points in an area.Demand CharacteristicsDemand can be characterized either as“fixed”_or“inelastic”_or“elastic”;the later meaning that demand is affected by the performance and services provided by the public transportation network.Lee and Vuchic_2005_distinguished between two types of elastic demand:_1_demand per mode affected by transportation services,with total demand for travel kept constant;and_2_total demand for travel varying as a result of the performance of the transportation system and its modes.Fan and Machemehl_2006b_noted that the complexity of the TRNDP has led researchers intoassuming fixed demand,despite its inherent elastic nature.However,since the early1980s, studies included aspects of elastic demand in modeling the TRNDP_Hasselstrom1981;Kocur and Hendrickson1982_.Van Nes et al._1988_applied a simultaneous distribution-modal split model based on transit deterrence for estimatingdemand for public transportation.In a series of studies,Chang and Schonfeld_1991,1993a,b_ and Spacovic et al._1994_estimated demand as a direct function of travel times and fares with respect to their elasticities,while Chien and Spacovic2001_,followed the same approach assuming that demand is additionally affected by headways,route spacing and fares.Finally, studies by Leblanc_1988_,Imam_1998_,Cipriani et al._2005_,Lee and Vuchic_2005_;and Fan and Machemehl_2006a_based demand estimation on mode choice models for estimating transit demand as a function of total demand for travel.中文译文：公交路线网络设计问题：回顾摘要：公共交通网络的有效设计让交通理论与实践成为众人关注的焦点，随之发展出了很多规划相关公交路线网络设计问题（TRNDP）的模型与方法。
本科毕业设计(论文)英文翻译模板
本科毕业设计（论文）英文翻译论文标题(中文)学院******姓名***专业*******班级**********大气探测2班学号*************** 大气探测、信处、两个专业填写电子信息工程。
生物医学工程、电子信息科学与技术、雷电防护科学与技术As its name implies, region growing is a procedure that groups pixels or subregions into larger regions based on predefined criteria. The basic approach is to start with a set of “seed ” points and from these grow regions by appending to each seed those gray level or color).be used to assignpixels to regions during the centroid of these clusters can be used as seeds.… … …左右手共面波导的建模与带通滤波器设计速发展之势，而它的出现却是源于上世纪本研究提出了一种新型混合左右手（CPW ）的独特功能。
目前这种有效电长度为0°的新型混合左右手共面波导（CRLH CPW ）谐振器正在兴起，这种谐振器工作在5GHz 时的体积比常规结构的谐振器缩减小49.1%。
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毕业设计(论文)外文文献原文及译文
毕业设计（论文）外文文献原文及译文Chapter 11. Cipher Techniques11.1 ProblemsThe use of a cipher without consideration of the environment in which it is to be used may not provide the security that the user expects. Three examples will make this point clear.11.1.1 Precomputing the Possible MessagesSimmons discusses the use of a "forward search" to decipher messages enciphered for confidentiality using a public key cryptosystem [923]. His approach is to focus on the entropy (uncertainty) in the message. To use an example from Section 10.1(page 246), Cathy knows that Alice will send one of two messages—BUY or SELL—to Bob. The uncertainty is which one Alice will send. So Cathy enciphers both messages with Bob's public key. When Alice sends the message, Bob intercepts it and compares the ciphertext with the two he computed. From this, he knows which message Alice sent.Simmons' point is that if the plaintext corresponding to intercepted ciphertext is drawn from a (relatively) small set of possible plaintexts, the cryptanalyst can encipher the set of possible plaintexts and simply search that set for the intercepted ciphertext. Simmons demonstrates that the size of the set of possible plaintexts may not be obvious. As an example, he uses digitized sound. The initial calculations suggest that the number of possible plaintexts for each block is 232. Using forward search on such a set is clearly impractical, but after some analysis of the redundancy in human speech, Simmons reduces the number of potential plaintexts to about 100,000. This number is small enough so that forward searches become a threat.This attack is similar to attacks to derive the cryptographic key of symmetric ciphers based on chosen plaintext (see, for example, Hellman's time-memory tradeoff attack [465]). However, Simmons' attack is for public key cryptosystems and does not reveal the private key. It only reveals the plaintext message.11.1.2 Misordered BlocksDenning [269] points out that in certain cases, parts of a ciphertext message can be deleted, replayed, or reordered.11.1.3 Statistical RegularitiesThe independence of parts of ciphertext can give information relating to the structure of the enciphered message, even if the message itself is unintelligible. The regularity arises because each part is enciphered separately, so the same plaintext always produces the same ciphertext. This type of encipherment is called code book mode, because each part is effectively looked up in a list of plaintext-ciphertext pairs.11.1.4 SummaryDespite the use of sophisticated cryptosystems and random keys, cipher systems may provide inadequate security if not used carefully. The protocols directing how these cipher systems are used, and the ancillary information that the protocols add to messages and sessions, overcome these problems. This emphasizes that ciphers and codes are not enough. The methods, or protocols, for their use also affect the security of systems.11.2 Stream and Block CiphersSome ciphers divide a message into a sequence of parts, or blocks, and encipher each block with the same key.Definition 11–1. Let E be an encipherment algorithm, and let Ek(b) bethe encipherment of message b with key k. Let a message m = b1b2…, whereeach biis of a fixed length. Then a block cipher is a cipher for whichE k (m) = Ek(b1)Ek(b2) ….Other ciphers use a nonrepeating stream of key elements to encipher characters of a message.Definition 11–2. Let E be an encipherment algorithm, and let Ek(b) bethe encipherment of message b with key k. Let a message m = b1b2…, whereeach bi is of a fixed length, and let k = k1k2…. Then a stream cipheris a cipher for which Ek (m) = Ek1(b1)Ek2(b2) ….If the key stream k of a stream cipher repeats itself, it is a periodic cipher.11.2.1 Stream CiphersThe one-time pad is a cipher that can be proven secure (see Section 9.2.2.2, "One-Time Pad"). Bit-oriented ciphers implement the one-time pad by exclusive-oring each bit of the key with one bit of the message. For example, if the message is 00101 and the key is 10010, the ciphertext is01||00||10||01||10 or 10111. But how can one generate a random, infinitely long key?11.2.1.1 Synchronous Stream CiphersTo simulate a random, infinitely long key, synchronous stream ciphers generate bits from a source other than the message itself. The simplest such cipher extracts bits from a register to use as the key. The contents of the register change on the basis of the current contents of the register.Definition 11–3. An n-stage linear feedback shift register (LFSR)consists of an n-bit register r = r0…rn–1and an n-bit tap sequence t =t 0…tn–1. To obtain a key bit, ris used, the register is shifted one bitto the right, and the new bit r0t0⊕…⊕r n–1t n–1 is inserted.The LFSR method is an attempt to simulate a one-time pad by generating a long key sequence from a little information. As with any such attempt, if the key is shorter than the message, breaking part of the ciphertext gives the cryptanalyst information about other parts of the ciphertext. For an LFSR, a known plaintext attack can reveal parts of the key sequence. If the known plaintext is of length 2n, the tap sequence for an n-stage LFSR can be determined completely.Nonlinear feedback shift registers do not use tap sequences; instead, the new bit is any function of the current register bits.Definition 11–4. An n-stage nonlinear feedback shift register (NLFSR)consists of an n-bit register r = r0…rn–1. Whenever a key bit is required,ris used, the register is shifted one bit to the right, and the new bitis set to f(r0…rn–1), where f is any function of n inputs.NLFSRs are not common because there is no body of theory about how to build NLFSRs with long periods. By contrast, it is known how to design n-stage LFSRs with a period of 2n– 1, and that period is maximal.A second technique for eliminating linearity is called output feedback mode. Let E be an encipherment function. Define k as a cryptographic key,(r) and define r as a register. To obtain a bit for the key, compute Ekand put that value into the register. The rightmost bit of the result is exclusive-or'ed with one bit of the message. The process is repeated until the message is enciphered. The key k and the initial value in r are the keys for this method. This method differs from the NLFSR in that the register is never shifted. It is repeatedly enciphered.A variant of output feedback mode is called the counter method. Instead of using a register r, simply use a counter that is incremented for every encipherment. The initial value of the counter replaces r as part of the key. This method enables one to generate the ith bit of the key without generating the bits 0…i – 1. If the initial counter value is i, set. In output feedback mode, one must generate all the register to i + ithe preceding key bits.11.2.1.2 Self-Synchronous Stream CiphersSelf-synchronous ciphers obtain the key from the message itself. The simplest self-synchronous cipher is called an autokey cipher and uses the message itself for the key.The problem with this cipher is the selection of the key. Unlike a one-time pad, any statistical regularities in the plaintext show up in the key. For example, the last two letters of the ciphertext associated with the plaintext word THE are always AL, because H is enciphered with the key letter T and E is enciphered with the key letter H. Furthermore, if theanalyst can guess any letter of the plaintext, she can determine all successive plaintext letters.An alternative is to use the ciphertext as the key stream. A good cipher will produce pseudorandom ciphertext, which approximates a randomone-time pad better than a message with nonrandom characteristics (such as a meaningful English sentence).This type of autokey cipher is weak, because plaintext can be deduced from the ciphertext. For example, consider the first two characters of the ciphertext, QX. The X is the ciphertext resulting from enciphering some letter with the key Q. Deciphering, the unknown letter is H. Continuing in this fashion, the analyst can reconstruct all of the plaintext except for the first letter.A variant of the autokey method, cipher feedback mode, uses a shift register. Let E be an encipherment function. Define k as a cryptographic(r). The key and r as a register. To obtain a bit for the key, compute Ek rightmost bit of the result is exclusive-or'ed with one bit of the message, and the other bits of the result are discarded. The resulting ciphertext is fed back into the leftmost bit of the register, which is right shifted one bit. (See Figure 11-1.)Figure 11-1. Diagram of cipher feedback mode. The register r is enciphered with key k and algorithm E. The rightmost bit of the result is exclusive-or'ed with one bit of the plaintext m i to produce the ciphertext bit c i. The register r is right shifted one bit, and c i is fed back into the leftmost bit of r.Cipher feedback mode has a self-healing property. If a bit is corrupted in transmission of the ciphertext, the next n bits will be deciphered incorrectly. But after n uncorrupted bits have been received, the shift register will be reinitialized to the value used for encipherment and the ciphertext will decipher properly from that point on.As in the counter method, one can decipher parts of messages enciphered in cipher feedback mode without deciphering the entire message. Let the shift register contain n bits. The analyst obtains the previous n bits of ciphertext. This is the value in the shift register before the bit under consideration was enciphered. The decipherment can then continue from that bit on.11.2.2 Block CiphersBlock ciphers encipher and decipher multiple bits at once, rather than one bit at a time. For this reason, software implementations of block ciphers run faster than software implementations of stream ciphers. Errors in transmitting one block generally do not affect other blocks, but as each block is enciphered independently, using the same key, identical plaintext blocks produce identical ciphertext blocks. This allows the analyst to search for data by determining what the encipherment of a specific plaintext block is. For example, if the word INCOME is enciphered as one block, all occurrences of the word produce the same ciphertext.To prevent this type of attack, some information related to the block's position is inserted into the plaintext block before it is enciphered. The information can be bits from the preceding ciphertext block [343] or a sequence number [561]. The disadvantage is that the effective block size is reduced, because fewer message bits are present in a block.Cipher block chaining does not require the extra information to occupy bit spaces, so every bit in the block is part of the message. Before a plaintext block is enciphered, that block is exclusive-or'ed with the preceding ciphertext block. In addition to the key, this technique requires an initialization vector with which to exclusive-or the initial plaintext block. Taking Ekto be the encipherment algorithm with key k, and I to be the initialization vector, the cipher block chaining technique isc 0 = Ek(m⊕I)c i = Ek(mi⊕ci–1) for i > 011.2.2.1 Multiple EncryptionOther approaches involve multiple encryption. Using two keys k and k' toencipher a message as c = Ek' (Ek(m)) looks attractive because it has aneffective key length of 2n, whereas the keys to E are of length n. However, Merkle and Hellman [700] have shown that this encryption technique can be broken using 2n+1encryptions, rather than the expected 22n(see Exercise 3).Using three encipherments improves the strength of the cipher. There are several ways to do this. Tuchman [1006] suggested using two keys k and k':c = Ek (Dk'(Ek(m)))This mode, called Encrypt-Decrypt-Encrypt (EDE) mode, collapses to a single encipherment when k = k'. The DES in EDE mode is widely used in the financial community and is a standard (ANSI X9.17 and ISO 8732). It is not vulnerable to the attack outlined earlier. However, it is vulnerable to a chosen plaintext and a known plaintext attack. If b is the block size in bits, and n is the key length, the chosen plaintext attacktakes O(2n) time, O(2n) space, and requires 2n chosen plaintexts. The known plaintext attack requires p known plaintexts, and takes O(2n+b/p) time and O(p) memory.A second version of triple encipherment is the triple encryption mode [700]. In this mode, three keys are used in a chain of encipherments.c = Ek (Ek'(Ek''(m)))The best attack against this scheme is similar to the attack on double encipherment, but requires O(22n) time and O(2n) memory. If the key length is 56 bits, this attack is computationally infeasible.11.3 Networks and CryptographyBefore we discuss Internet protocols, a review of the relevant properties of networks is in order. The ISO/OSI model [990] provides an abstract representation of networks suitable for our purposes. Recall that the ISO/OSI model is composed of a series of layers (see Figure 11-2). Each host, conceptually, has a principal at each layer that communicates with a peer on other hosts. These principals communicate with principals at the same layer on other hosts. Layer 1, 2, and 3 principals interact only with similar principals at neighboring (directly connected) hosts. Principals at layers 4, 5, 6, and 7 interact only with similar principals at the other end of the communication. (For convenience, "host" refers to the appropriate principal in the following discussion.)Figure 11-2. The ISO/OSI model. The dashed arrows indicate peer-to-peer communication. For example, the transport layers are communicating with each other. The solid arrows indicate the actual flow of bits. For example, the transport layer invokes network layer routines on the local host, which invoke data link layer routines, which put the bits onto the network. The physical layer passes the bits to the next "hop," or host, on the path. When the message reaches the destination, it is passed up to the appropriatelevel.Each host in the network is connected to some set of other hosts. They exchange messages with those hosts. If host nob wants to send a message to host windsor, nob determines which of its immediate neighbors is closest to windsor (using an appropriate routing protocol) and forwards the message to it. That host, baton, determines which of its neighbors is closest to windsor and forwards the message to it. This process continues until a host, sunapee, receives the message and determines that windsor is an immediate neighbor. The message is forwarded to windsor, its endpoint.Definition 11–5. Let hosts C0, …, Cnbe such that Ciand Ci+1are directlyconnected, for 0 i < n. A communications protocol that has C0 and Cnasits endpoints is called an end-to-end protocol. A communications protocolthat has Cj and Cj+1as its endpoints is called a link protocol.The difference between an end-to-end protocol and a link protocol is that the intermediate hosts play no part in an end-to-end protocol other than forwarding messages. On the other hand, a link protocol describes how each pair of intermediate hosts processes each message.The protocols involved can be cryptographic protocols. If the cryptographic processing is done only at the source and at the destination, the protocol is an end-to-end protocol. If cryptographic processing occurs at each host along the path from source to destination, the protocolis a link protocol. When encryption is used with either protocol, we use the terms end-to-end encryption and link encryption, respectively.In link encryption, each host shares a cryptographic key with its neighbor. (If public key cryptography is used, each host has its neighbor's public key. Link encryption based on public keys is rare.) The keys may be set on a per-host basis or a per-host-pair basis. Consider a network with four hosts called windsor, stripe, facer, and seaview. Each host is directly connected to the other three. With keys distributed on a per-host basis, each host has its own key, making four keys in all. Each host has the keys for the other three neighbors, as well as its own. All hosts use the same key to communicate with windsor. With keys distributed on a per-host-pair basis, each host has one key per possible connection, making six keys in all. Unlike the per-host situation, in the per-host-pair case, each host uses a different key to communicate with windsor. The message is deciphered at each intermediate host, reenciphered for the next hop, and forwarded. Attackers monitoring the network medium will not be able to read the messages, but attackers at the intermediate hosts will be able to do so.In end-to-end encryption, each host shares a cryptographic key with each destination. (Again, if the encryption is based on public key cryptography, each host has—or can obtain—the public key of each destination.) As with link encryption, the keys may be selected on a per-host or per-host-pair basis. The sending host enciphers the message and forwards it to the first intermediate host. The intermediate host forwards it to the next host, and the process continues until the message reaches its destination. The destination host then deciphers it. The message is enciphered throughout its journey. Neither attackers monitoring the network nor attackers on the intermediate hosts can read the message. However, attackers can read the routing information used to forward the message.These differences affect a form of cryptanalysis known as traffic analysis.A cryptanalyst can sometimes deduce information not from the content ofthe message but from the sender and recipient. For example, during the Allied invasion of Normandy in World War II, the Germans deduced which vessels were the command ships by observing which ships were sending and receiving the most signals. The content of the signals was not relevant; their source and destination were. Similar deductions can reveal information in the electronic world.第十一章密码技术11．1问题在没有考虑加密所要运行的环境时，加密的使用可能不能提供用户所期待的安全。
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模型预测油田水中溶解的碳酸钙含量：压力和温度的影响XXX 译摘要：油田中水垢沉积会对储层造成伤害、堵塞地层孔道、表面以及注入设备。
碳酸钙是水中最常见的结垢化合物之一，储层产生的盐水会使压力和温度降低，储层压力降低会使CaCO3的溶解度降低，进而提高体系中碳酸钙的饱和速率，而温度下降会产生相反的结果。
因此温度和压力一起作用的结果可能增加或减小CaCO3溶解度，用体系温度的变化来指定其压力的变化。
因此，在石油生产系统中精确的预测方法的应用备受关注。
目前的研究重点是运用基于最小二乘支持向量机(LSSVM)预测模型来估计油田水中溶解碳酸钙浓度的大小。
用超优化参数（r和C2）的遗传算法（GA）嵌入到LSSVM模型，这种方法可简单准确的预测油田卤水中溶解碳酸钙浓度的最小量。
1.引言随着油田卤水压力和温度变化，气体可能会从储层到地表的运动，导致某些固体沉淀。
为了保持注水井压力平衡并将油运移到生产井，有时需要将卤水注入到储层中，因此，过量的盐垢可以沉积在储层或井眼内。
对于大部分油田结垢多会发生在此过程中。
碳酸钙沉积通常是一个自发的过程，沉积形成的主要原因是二氧化碳从水相逸出，导致油气层的压力下降，该过程会除去了水中的碳酸，直到方解石溶解完全。
在恒定二氧化碳分压下，方解石的溶解性随温度的降低而降低[1-4]。
根据公式（1），碳酸钙沉积垢来自碳酸钙沉淀：Ca2+ + CO32-→ CaCO3↓下面的公式为碳酸的电离式[5–7]：CO2 + H2O → H2CO3H2CO3→ H+ + HCO3-HCO3-→ H+ + CO32-若要形成碳酸氢根离子和氢离子，碳酸要电离，因为碳酸的第一电离常数远大于它的第二电离常数，从碳酸第一电离离子化的氢离子与水中自由的碳酸根离子结合。
此外，碳酸钙沉淀的方程式可以说明[8–10]：Ca(HCO3)2→CaCO3↓+ CO2↑+ H2O碳酸钙的溶解度很大程度上取决于二氧化碳在水中的含量（即二氧化碳气体逸出时所需最小的分压）[10–12]。
二氧化碳气体注入到储层卤水可产生酸性溶液，能溶解地层中的方解石，压力的下降导致二氧化碳气体从酸性溶液中逸出，并且在近井地带的地层空隙和射孔眼处沉积碳酸盐垢。
而且，在井筒附近产生的垢会进一步导致气井产能的下降和更多结垢的产生[13,14]。
Bahadori借助范德蒙德行列式的相关性来研究估算油田卤水溶解的碳酸钙浓度[15]。
本论文中涉及到的最小二乘支持向量机（LSSVM），是作为一种传统简化的支持向量机（SVM）来预测油田卤水中溶解碳酸钙浓度量的大小。
遗传算法（GA）偶合来优化主题，用于确定超参数。
据我们所了解的，目前还没有文献记录采用支持向量方法进行天然气产能建模。
2.原理理论2.1 最小二乘支持向量机（LSSVM）支持向量机（SVM）最初形成的是一种智能化的系统方法[16]。
支持向量机已被广泛应用于分类，回归分析和模式识别，是一种非常有效的而方法[17]。
支持向量机的原理是对于线性不可分的情况，通过使用非线性映射算法将低维输入空间线性不可分的样本转化为高维特征空间使其线性可分，从而使得高维特征空间采用线性算法对样本的非线性特征进行线性分析成为可能，并且基于结构风险最小化理论之上在特征空间中建构最优分割超平面[18]。
这种新方法基于结垢风险最小化理论（SRM）和统计学理论（SLT）概念[19]。
支持向量机通过求解二次规划（QP）问题来发现目标函数的全局最小值，而不是获得局部最优解。
与其他回归技术不同，二次规划问题是一个凸函数[20]。
然而，这种做法可能会耗时并且困难，因为它需要各种非线性公式（QP），Suyken 和Vandewalle [21]建议最小二乘支持向量机（LSSVM）作为支持向量机（SVM）的一个备用方法。
SVM也具有LSSVM类似的优点。
此外，需要一个二次规划（QP）可代替多个非线性公式（线性规划），这使得计算问题简单且容易处理。
LSSVM公式中的非线性函数可表示如下，给出训练集｛Xk，Yk｝，K=1，2，…N，其中Xk∈R n，是第i个输入到输入集合空间，Yk∈R输出值为特定输入变量的对应值（即Xk），N是指训练样本的数目，通过一个非线性映射，把样本空间映射到一个高维乃至无穷维的特征空间中，构造的回归模型如下：其中w表示权重向量，而b是一个偏置术语，上表“n”是数据区域的范围，“n h”表示未知区域（高维和无穷维）的范围[20]。
当应用LSSVM时会产生一个新的优化问题，该方法涉及的优化问题如下：根据下列等式进行约束：其中r表示正则化参数的平衡训练误差和模型阐述[19]，e k是回归误差。
拉格朗日乘子理论构造如下，以找到优化问题的约束条件：其中，a k拉格朗日乘子或支集值，为了获得上述方程的解，对上述方程中的变量w，b，e k，a k微分：在除去变量w和e后，获得Karush-Kuhn-Trucker系统如下：其中y=[y1，…yN] T，1N=[1，…1] T，a=[a1，…aN] T，I是一个单位矩阵，是内核函数，必须满足Mercerd的条件内核函数三种典型的选择方法如下所示：（1）线性核函数K(x,y)=x·y；（2）多项式核函数K(x,y)=[(x·y)+1]^d；（3）径向基函数K(x,y)=exp(-|x-y|^2/d^2）由此LSSVM模型函数估计如下：其中（b，a）是式（14）线性系统的解。
文献中，一些综合性描述支持向量机内容是可用的[16,21,23]，并且对最小二乘支持向量机理论的解释很详细[21,24]，此外，刘等人[25–27]，提供了LSSVM理论价值的解释，以及SVM和LSSVM在有关情况下的区别，所以，感兴趣的读者可以参考上述文献以了解更多的细节。
2.2 遗传算法遗传算法（Genetic Algorithm）是模拟达尔文生物进化论的自然选择和遗传学机理的生物进化过程的计算模型，是一种通过模拟自然进化过程搜索最优解的方法。
遗传算法是从代表问题可能潜在的解集的一个种群（population）开始的，而一个种群则由经过基因（gene）编码的一定数目的个体(individual)组成。
每个个体实际上是染色体(chromosome)带有特征的实体。
染色体作为遗传物质的主要载体，即多个基因的集合，其内部表现（即基因型）是某种基因组合，它决定了个体的形状的外部表现。
因此，在一开始需要实现从表现型到基因型的映射即编码工作。
由于仿照基因编码的工作很复杂，我们往往进行简化，如二进制编码，初代种群产生之后，按照适者生存和优胜劣汰的原理，逐代（generation）演化产生出越来越好的近似解，在每一代，根据问题域中个体的适应度（fitness）大小选择（selection）个体，并借助于自然遗传学的遗传算子（genetic operators）进行组合交叉（crossover）和变异（mutation），产生出代表新的解集的种群。
这个过程将导致种群像自然进化一样的后生代种群比前代更加适应于环境，末代种群中的最优个体经过解码（decoding），可以作为问题近似最优解。
1. 初始化：此阶段由r和C2超参数来创造染色体，C2表示正规化因素，r 代表RBF核函数的宽度，染色体A的定义为A=｛a1,a2｝，其中a1和a2与r和C2相对应的，此外，选定种群数量大小为20的，最大的代分配给100，初始化代分配给0。
2. 评价适应度: 此阶段，对每一个解(染色体)指定一个适应度的值，根据问题求解的实际接近程度来指定(以便逼近求解问题的答案)。
测试数据的平均相对偏差为适应度函数。
其中Ca i actual表示实际碳酸钙浓度的大小，Ca i predicted表示用LSSVM模型预测碳酸钙浓度的级数。
3. 选择：选择的目的是把优化的个体(或解)直接遗传到下一代或通过配对交叉产生新的个体再遗传到下一代。
轮盘赌选择法（roulette wheel selection）是最简单也是最常用的选择方法。
图1 遗传算法的超参数选择流程图4. 交叉：所谓交叉是指把两个父代个体的部分结构加以替换重组而生成新个体的操作。
生成每一对新的染色体的可能性为0.8，且执行单点交叉，新染色体结合为新的个体后代。
5. 变异：变异操作遵循交叉操作，并确认是否有染色体变异来进行进一步创造，在目前的进展中，均匀变异概率为0.05，此进化方法设计并执行。
6. 下一代：一代一代演化下去，直到达到期望的解为止。
7. 终止条件：当最优个体的适应度达到给定的阈值，或者最优个体的适应度和群体适应度不再上升时，或者迭代次数达到预设的代数时，算法终止，预设代数为100。
3.方法论GA-LSSVM是由实验室1.8免费工具箱和遗传算法工具箱MATLABR2009a 对LSSVM变量进行优化。
在识别和收集数据之后，再定义LSSVM模型的输入和输出参数，在文献数据库的基础上，油田卤水中溶解碳酸钙浓度量作为LSSVM 预测模型的输出参数，该模型有两个输入参数：压力和温度。
识别收集的实际数据库分为两个子集。
首先在预测培训的过程中，利用整个数据的80%（63个数据点），50个等于数据线，剩余的13个组成样本设置，来检验上述建议方法的评估能力和完整性。
与其他内核函数比较，RBF核的参数少并且有最佳的整体性能，因此RBF 核函数在文献中被视为一种合适有效的内核函数[30,31]。
在利用LSSVM模型和RBF核函数开发模型，在上述方程中超参数r2和C2规范很重要，因为这两个参数在获得高估计完整性和概括性的LSSVM模型中有很重要的作用，其中r2为正则化因子，C为样本方差[20]。
根据Ahmadi等，其中包括Levenberg-Marquardt（LM）和Simplex SlmelatedAnnealingAlgvrithm(M-SIMPSON)不倡导不是基于逐代优化技术的方法，因为支持向量机无法处理高非线性问题。
基于逐代优化技术即遗传算法，已经用于对超参数（r2和C2）的评估，AARD的测试数据为遗传算法的适应度，重复优化过程才肯能确定，相应的ARRD变量如图2所示.在图2中，36代后ARRD稳定，并达到最佳态，通过这种方式，从油田卤水溶解碳酸钙浓度量获得r2和C2级数值，分别为20.961370794和1072577.9326。
图2-ARRD变异随代数的变化4.结果和讨论在本研究中，确定参数r2和均方误差（MSE）评价预测模型有效性和准确性的指标，计算MSE和r2的表达式如下：其中，N表示数据点的数量，y i actual表示第i个数值，y i predicted表示第i个输出模型值，y i actual平均表示实验观察数据的平均值。