交通运输-外文翻译-外文文献-英文文献-北京运输系统
智能交通系统中英文对照外文翻译文献
智能交通系统中英文对照外文翻译文献(文档含英文原文和中文翻译)原文:Traffic Assignment Forecast Model Research in ITS IntroductionThe intelligent transportation system (ITS) develops rapidly along with the city sustainable development, the digital city construction and the development of transportation. One of the main functions of the ITS is to improve transportation environment and alleviate the transportation jam, the most effective method to gain the aim is to forecast the traffic volume of the local network and the important nodes exactly with GIS function of path analysis and correlation mathematic methods, and this will lead a better planning of the traffic network. Traffic assignment forecast is an important phase of traffic volume forecast. It will assign the forecasted traffic to every way in the traffic sector. If the traffic volume of certain road is too big, which would bring on traffic jam, planners must consider the adoption of new roads or improving existing roads to alleviate the traffic congestion situation. This study attempts to present an improved traffic assignment forecast model, MPCC, based on analyzing the advantages and disadvantages of classic traffic assignment forecast models, and test the validity of the improved model in practice.1 Analysis of classic models1.1 Shortcut traffic assignmentShortcut traffic assignment is a static traffic assignment method. In this method, the traffic load impact in the vehicles’ travel is not considered, and the traffic impedance (travel time) is a constant. The traffic volume of every origination-destination couple will be assigned to the shortcut between the origination and destination, while the traffic volume of other roads in this sector is null. This assignment method has the advantage of simple calculation; however, uneven distribution of the traffic volume is its obvious shortcoming. Using this assignment method, the assignment traffic volume will be concentrated on the shortcut, which isobviously not realistic. However, shortcut traffic assignment is the basis of all theother traffic assignment methods.1.2 Multi-ways probability assignmentIn reality, travelers always want to choose the shortcut to the destination, whichis called the shortcut factor; however, as the complexity of the traffic network, thepath chosen may not necessarily be the shortcut, which is called the random factor.Although every traveler hopes to follow the shortcut, there are some whose choice isnot the shortcut in fact. The shorter the path is, the greater the probability of beingchosen is; the longer the path is, the smaller the probability of being chosen is.Therefore, the multi-ways probability assignment model is guided by the LOGIT model:∑---=n j ii i F F p 1)exp()exp(θθ (1)Where i p is the probability of the path section i; i F is the travel time of thepath section i; θ is the transport decision parameter, which is calculated by the followprinciple: firstly, calculate the i p with different θ (from 0 to 1), then find the θwhich makes i p the most proximate to the actual i p .The shortcut factor and the random factor is considered in multi-ways probabilityassignment, therefore, the assignment result is more reasonable, but the relationshipbetween traffic impedance and traffic load and road capacity is not considered in thismethod, which leads to the assignment result is imprecise in more crowded trafficnetwork. We attempt to improve the accuracy through integrating the several elements above in one model-MPCC.2 Multi-ways probability and capacity constraint model2.1 Rational path aggregateIn order to make the improved model more reasonable in the application, theconcept of rational path aggregate has been proposed. The rational path aggregate,which is the foundation of MPCC model, constrains the calculation scope. Rationalpath aggregate refers to the aggregate of paths between starts and ends of the trafficsector, defined by inner nodes ascertained by the following rules: the distancebetween the next inner node and the start can not be shorter than the distance betweenthe current one and the start; at the same time, the distance between the next innernode and the end can not be longer than the distance between the current one and theend. The multi-ways probability assignment model will be only used in the rationalpath aggregate to assign the forecast traffic volume, and this will greatly enhance theapplicability of this model.2.2 Model assumption1) Traffic impedance is not a constant. It is decided by the vehicle characteristicand the current traffic situation.2) The traffic impedance which travelers estimate is random and imprecise.3) Every traveler chooses the path from respective rational path aggregate.Based on the assumptions above, we can use the MPCC model to assign thetraffic volume in the sector of origination-destination couples.2.3 Calculation of path traffic impedanceActually, travelers have different understanding to path traffic impedance, butgenerally, the travel cost, which is mainly made up of forecast travel time, travellength and forecast travel outlay, is considered the traffic impedance. Eq. (2) displaysthis relationship. a a a a F L T C γβα++= (2)Where a C is the traffic impedance of the path section a; a T is the forecast traveltime of the path section a; a L is the travel length of the path section a; a F is theforecast travel outlay of the path section a; α, β, γ are the weight value of that threeelements which impact the traffic impedance. For a certain path section, there aredifferent α, β and γ value for different vehicles. We can get the weighted average of α,β and γ of each path section from the statistic percent of each type of vehicle in thepath section.2.4 Chosen probability in MPCCActually, travelers always want to follow the best path (broad sense shortcut), butbecause of the impact of random factor, travelers just can choose the path which is ofthe smallest traffic impedance they estimate by themselves. It is the key point ofMPCC. According to the random utility theory of economics, if traffic impedance is considered as the negativeutility, the chosen probability rs p of origination-destinationpoints couple (r, s) should follow LOGIT model:∑---=n j jrs rs bC bC p 1)exp()exp( (3) where rs p is the chosen probability of the pathsection (r, s);rs C is the traffic impedance of the path sect-ion (r, s); j C is the trafficimpedance of each path section in the forecast traffic sector; b reflects the travelers’cognition to the traffic impedance of paths in the traffic sector, which has reverseratio to its deviation. If b → ∞ , the deviation of understanding extent of trafficimpedance approaches to 0. In this case, all the travelers will follow the path whichis of the smallest traffic impedance, which equals to the assignment results withShortcut Traffic Assignment. Contrarily, if b → 0, travelers ’ understanding error approaches infinity. In this case, the paths travelers choose are scattered. There is anobjection that b is of dimension in Eq.(3). Because the deviation of b should beknown before, it is difficult to determine the value of b. Therefore, Eq.(3) is improvedas follows:∑---=n j OD j OD rsrs C bC C bC p 1)exp()exp(，∑-=n j j OD C n C 11（4） Where OD C is the average of the traffic impedance of all the as-signed paths; bwhich is of no dimension, just has relationship to the rational path aggregate, ratherthan the traffic impedance. According to actual observation, the range of b which is anexperience value is generally between 3.00 to 4.00. For the more crowded cityinternal roads, b is normally between 3.00 and 3.50.2.5 Flow of MPCCMPCC model combines the idea of multi-ways probability assignment anditerative capacity constraint traffic assignment.Firstly, we can get the geometric information of the road network and OD trafficvolume from related data. Then we determine the rational path aggregate with themethod which is explained in Section 2.1.Secondly, we can calculate the traffic impedance of each path section with Eq.(2),Fig.1 Flowchart of MPCC which is expatiated in Section 2.3.Thirdly, on the foundation of the traffic impedance of each path section, we cancalculate the respective forecast traffic volume of every path section with improvedLOGIT model (Eq.(4)) in Section 2.4, which is the key point of MPCC.Fourthly, through the calculation processabove, we can get the chosen probability andforecast traffic volume of each path section, but itis not the end. We must recalculate the trafficimpedance again in the new traffic volumesituation. As is shown in Fig.1, because of theconsideration of the relationship between trafficimpedance and traffic load, the traffic impedanceand forecast assignment traffic volume of everypath will be continually amended. Using therelationship model between average speed andtraffic volume, we can calculate the travel timeand the traffic impedance of certain path sect-ionunder different traffic volume situation. For theroads with different technical levels, therelationship models between average speeds totraffic volume are as follows: 1) Highway: 1082.049.179AN V = (5) 2) Level 1 Roads: 11433.084.155AN V = (6) 3) Level 2 Roads: 66.091.057.112AN V = (7) 4) Level 3 Roads: 3.132.01.99AN V = (8) 5) Level 4 Roads: 0988.05.70A N V =(9) Where V is the average speed of the path section; A N is the traffic volume of thepath section.At the end, we can repeat assigning traffic volume of path sections with themethod in previous step, which is the idea of iterative capacity constraint assignment,until the traffic volume of every path section is stable.译文智能交通交通量分配预测模型介绍随着城市的可持续化发展、数字化城市的建设以及交通运输业的发展，智能交通系统（ITS）的发展越来越快。
营运管理 外文翻译 外文文献 英文文献 对整个行业中营运资金管理的研究
An Analysis of Working Capital Management Results Across IndustriesGreg Filbeck. Schweser Study ProgramThomas M. Krueger. University of Wisconsin-La Crosse AbstractFirms are able to reduce financing costs and/or increase the funds available for expansion by minimizing the amount of funds tied up in current assets. We provide insights into the performance of surveyed firms across key components of working capital management by using the CFO magazine’s annual Working Capital Management Survey. We discover that significant differences exist between industries in working capital measures across time. In addition. we discover that these measures for working capital change significantly within industries across time.IntroductionThe importance of efficient working capital management is indisputable. Working capital is the difference between resources in cash or readily convertible into cash (Current Assets) and organizational commitments for which cash will soon be required (Current Liabilities). The objective of working capital management is to maintain the optimum balance of each of the working capital components. Business viability relies on the ability to effectively manage receivables. inventory. and payables. Firms are able to reduce financing costs and/or increase the funds available for expansion by minimizing the amount of funds tied up in current assets. Much managerial effort is expended in bringing non-optimal levels of current assets and liabilities back toward optimal levels. An optimal level would be one in which a balance is achieved between risk and efficiency.A recent example of business attempting to maximize working capital management is the recurrent attention being given to the application of Six Sigma® methodology. Six Sigma® methodologies help companies measure and ensure quality in all areas of the enterprise. When used to identify and rectify discrepancies. inefficiencies and erroneous transactions in the financial supply chain. Six Sigma® reduces Days Sales Outstanding (DSO). accelerates the payment cycle. improves customer satisfaction and reduces the necessary amount and cost of working capital needs. There appear to be many success stories. including Jennifer Towne’s (2002) r eport of a 15 percent decrease in days that sales are outstanding. resulting in an increased cash flow of approximately $2 million at Thibodaux Regional Medical Center. Furthermore. bad debts declined from $3.4 million to $600.000. However. Waxer’s (2003) study of multiple firms employing Six Sigma® finds that it is really a “get rich slow” technique with a rate of return hovering in the 1.2 – 4.5 percent range.Even in a business using Six Sigma® methodology. an “optimal” level of working capital management needs to be identified.Even in a business using Six Sigma® methodology. an “optimal” level of working capital management needs to be identified. Industry factors may impact firm credit policy. inventory management. and bill-paying activities. Some firms may be better suited to minimize receivables and inventory. while others maximize payables. Another aspect of “optimal” is the extent to which poor financial results can be tied to sub-optimal performance. Fortunately. these issues are testable with data published by CFO magazine. which claims to be the source of “tools and information for the financial executive.” and are the subject of this research.In addition to providing mean and variance values for the working capital measures and the overall metric. two issues will be addressed in this research. One research question is. “are firms within a particular industry clustered together at consistent levels of working capital measures?” For instance. are firms in one industry able to quickly transfer sales into cash. while firms from another industry tend to have high sales levels for the particular level of inventory . The other research question is. “does working capital management performance for firms within a given industry change from year-to-year?”The following section presents a brief literature review. Next. the research method is described. including some information about the annual Working Capital Management Survey published by CFO magazine. Findings are then presented and conclusions are drawn.Related LiteratureThe importance of working capital management is not new to the finance literature. Over twenty years ago. Largay and Stickney (1980) reported that the then-recent bankruptcy of W.T. Grant. a nationwide chain of department stores. should have been anticipated because the corporation had been running a deficit cash flow from operations for eight of the last ten years of its corporate life. As part of a study of the Fortune 500’s financial management practices. Gilbert and Reichert (1995) find that accounts receivable management models are used in 59 percent of these firms to improve working capital projects. while inventory management models were used in 60 percent of the companies. More recently. Farragher. Kleiman and Sahu (1999) find that 55 percent of firms in the S&P Industrial index complete some form of a cash flow assessment. but did not present insights regarding accounts receivable and inventory management. or the variations of any current asset accounts or liability accounts across industries. Thus. mixed evidence exists concerning the use of working capital management techniques.Theoretical determination of optimal trade credit limits are the subject of many articles over the years (e.g.. Schwartz 1974; Scherr 1996). with scant attention paid to actual accounts receivable management. Across a limitedsample. Weinraub and Visscher (1998) observe a tendency of firms with low levels of current ratios to also have low levels of current liabilities. Simultaneously investigating accounts receivable and payable issues. Hill. Sartoris. and Ferguson (1984) find differences in the way payment dates are defined. Payees define the date of payment as the date payment is received. while payors view payment as the postmark date. Additional WCM insight across firms. industries. and time can add to this body of research.Maness and Zietlow (2002. 51. 496) presents two models of value creation that incorporate effective short-term financial management activities. However. these models are generic models and do not consider unique firm or industry influences. Maness and Zietlow discuss industry influences in a short paragraph that includes the observation that. “An industry a company is located in may have more influence on that company’s fortun es than overall GNP” (2002. 507). In fact. a careful review of this 627-page textbook finds only sporadic information on actual firm levels of WCM dimensions. virtually nothing on industry factors except for some boxed items with titles such as. “Should a Retailer Offer an In-House Credit Card” (128) and nothing on WCM stability over time. This research will attempt to fill this void by investigating patterns related to working capital measures within industries and illustrate differences between industries across time.An extensive survey of library and Internet resources provided very few recent reports about working capital management. The most relevant set of articles was Weisel and Bradley’s (2003) article on cash flow management and one of inventory control as a result of effective supply chain management by Hadley (2004).Research MethodThe CFO RankingsThe first annual CFO Working Capital Survey. a joint project with REL Consultancy Group. was published in the June 1997 issue of CFO (Mintz and Lezere 1997). REL is a London. England-based management consulting firm specializing in working capital issues for its global list of clients. The original survey reports several working capital benchmarks for public companies using data for 1996. Each company is ranked against its peers and also against the entire field of 1.000 companies. REL continues to update the original information on an annual basis.REL uses the “cash flow from operations” value located on firm cash flow statements to estimate cash conversion efficiency (CCE). This value indicates how well a company transforms revenues into cash flow. A “days of working capital” (DWC) value is based on the dollar amount in each of the aggregate. equally-weighted receivables. inventory. and payables ac counts. The “days of working capital” (DNC) represents the time period between purchase of inventory on acccount from vendor until the sale to the customer. the collection of the receivables. and payment receipt. Thus. it reflects the company’s ability to finance its core operations with vendor credit. A detailedinvestigation of WCM is possible because CFO also provides firm and industry values for days sales outstanding (A/R). inventory turnover. and days payables outstanding (A/P).Research FindingsAverage and Annual Working Capital Management Performance Working capital management component definitions and average values for the entire 1996 – 2000 period . Across the nearly 1.000 firms in the survey. cash flow from operations. defined as cash flow from operations divided by sales and referred to as “cash conversion efficiency” (CCE). averages 9.0 percent. Incorporating a 95 percent confidence interval. CCE ranges from 5.6 percent to 12.4 percent. The days working capital (DWC). defined as the sum of receivables and inventories less payables divided by daily sales. averages 51.8 days and is very similar to the days that sales are outstanding (50.6). because the inventory turnover rate (once every 32.0 days) is similar to the number of days that payables are outstanding (32.4 days). In all instances. the standard deviation is relatively small. suggesting that these working capital management variables are consistent across CFO reports.Industry Rankings on Overall Working Capital Management PerformanceCFO magazine provides an overall working capital ranking for firms in its survey. using the following equation:Industry-based differences in overall working capital management are presented for the twenty-six industries that had at least eight companies included in the rankings each year. In the typical year. CFO magazine ranks 970 companies during this period. Industries are listed in order of the mean overall CFO ranking of working capital performance. Since the best average ranking possible for an eight-company industry is 4.5 (this assumes that the eight companies are ranked one through eight for the entire survey). it is quite obvious that all firms in the petroleum industry must have been receiving very high overall working capital management rankings. In fact. the petroleum industry is ranked first in CCE and third in DWC (as illustrated in Table 5 and discussed later in this paper). Furthermore. the petroleum industry had the lowest standard deviation of working capital rankings and range of working capital rankings. The only other industry with a mean overall ranking less than 100 was the Electric & Gas Utility industry. which ranked second in CCE and fourth in DWC. The two industries with the worst working capital rankings were Textiles and Apparel. Textiles rank twenty-second in CCE and twenty-sixth in DWC. The apparel industry ranks twenty-third and twenty-fourth in the two working capital measuresConclusionsThe research presented here is based on the annual ratings of working capital management published in CFO magazine. Our findings indicate a consistency in how industries “stack up” against each other over time with respect to the working capital measures. However. the working capitalmeasures themselves are not static (i.e.. averages of working capital measures across all firms change annually); our results indicate significant movements across our entire sample over time. Our findings are important because they provide insight to working capital performance across time. and on working capital management across industries. These changes may be in explained in part by macroeconomic factors. Changes in interest rates. rate of innovation. and competition are likely to impact working capital management. As interest rates rise. there would be less desire to make payments early. which would stretch accounts payable. accounts receivable. and cash accounts.The ramifications of this study include the finding of distinct levels of WCM measures for different industries. which tend to be stable over time. Many factors help to explain this discovery. The improving economy during the period of the study may have resulted in improved turnover in some industries. while slowing turnover may have been a signal of troubles ahead. Our results should be interpreted cautiously. Our study takes places over a short time frame during a generally improving market. In addition. the survey suffers from survivorship bias – only the top firms within each industry are ranked each year and the composition of those firms within the industry can change annually.Further research may take one of two lines. First. there could be a study of whether stock prices respond to CFO magazine’s publication of working capital management ratings. Second. there could be a study of which. if any. of the working capital management components relate to share price performance. Given our results. these studies need to take industry membership into consideration when estimating stock price reaction to working capital management performance.外文翻译:对整个行业中营运资金管理的研究格雷格Filbeck.Schweser学习计划托马斯M克鲁格.威斯康星大学拉克罗斯摘要:企业能够降低融资成本或者尽量减少绑定在流动资产上的成立基金数额来用于扩大现有的资金。
传动系统离合器论文中英文对照资料外文翻译文献
中英文对照资料外文翻译文献Transmission SystemA Basic Parts of the transmission systemThe transmission system applies to the components needed to transfer the drive from the engine to the road wheels. The main components and their purposes are (1) Clutch --- to disengage the drive--- to provide a smooth take-up of the drive(2) Gearbox --- to increase the torque applied to the driving road wheels--- to enable the engine to operate within a given range of speed irrespective of the vehicle speed--- to give reverse motion of the vehicle--- to provide a neutral position so that the engine can run without moving the vehicle(3) Final drive --- to turn the drive through 90°--- to reduce the speed of the drive by a set amount to match the engine to the vehicle(4) Differential --- to allow the inner driving road wheel to rotate slower than the outerwheel when the vehicle is cornering, whilst it ensures that adrive is applied equally to both wheels.B Clutch and Clutch ServiceIn order to transmit the power of the engine to the road wheels of a car, a friction clutch and a change-speed gearbox are normally employed. The former is necessary in order to enable the drive to be taken up gradually and smoothly, while the latter provides different ratios of speed reduction from the engine to the wheels, to suit the particular conditions of running,A clutch performs two tasks:(1) it disengages the engine from the gearbox to allow for gear changing.(2) it is a means for gradually engaging the engine to the driving wheels, when a vehicle is to be moved from rest the clutch must engage a stationary gearbox shaft with the engine; this must be rotating at a high speed to provide sufficient power or else the load will be too great and the engine will start (come to test).C Clutch ActionTo start the engine, the driver must depress the clutch pedal. This disengages the gearbox from the engine. To move the car, the driver must reengage the gearbox to the engine. However, the engagement of the parts must be gradual. An engine at idle develops little power. If the two parts were connected too quickly, the engine would stall. The load must be applied gradually to operate the car smoothly.A driver depresses the clutch pedal to shift the gears inside the gearbox. After the driver releases the clutch pedal, the clutch must act as solid coupling device. It must transmit all engine power to the gearbox, without slipping.The clutch mechanism include three basic parts: driving member, driven member, operating members.●The driving memberThe driving member consists of two parts: the flywheel and the pressure plate. The flywheel is bolted directly to the engine crankshaft and rotates when the crankshaft turns. The pressure plate is bolted to the flywheel. The result is that both flywheel and pressure plate rotate together.●The driven memberThe driven member, or clutch disc, is located between the flywheel and pressure plate. The disc has a splined hub that locks to the splined input shaft on the gearbox .Any rotation of the clutch disc turns the input shaft .Likewise, any motion of the input shaft moves the clutch disc. The splines allow the clutch disc to move forward and backward on the shaft as it engages and disengages.The inner part of the clutch disc, called the hub flange, has a number of small coil springs. These springs are called torsional springs. They let the middle part of theclutch disc turn slightly on the hub. Thus, the springs absorb the torsional vibrations of the crankshaft. When the springs have compressed completely, the clutch moves back until the springs relax. In other words, the clutch absorbs these engine vibrations, preventing the vibrations from going through the drive train.●Operating MembersThese are the parts that release pressure from the clutch disc. The operating members consist of the clutch pedal, clutch return spring, clutch linkage, clutch fork, and throwout bearing. The clutch linkage includes the clutch pedal and a mechanical or hydraulic system to move the other operating members.When the clutch pedal is depressed, the clutch linkage operates the clutch fork .The clutch fork, or release fork, moves the throwout bearing against the pressure plate release levers. These levers then compress springs that normally hold the clutch disc tightly against the flywheel.At this point, the torque of the engine cannot turn the gearbox input shaft. The gears in the gearbox may be shifted or the vehicle can be brought to a full stop.When the clutch pedal is released, the pressure plate forces the clutch disc against the flywheel. The clutch return spring helps raise the pedal.D Clutch ServiceThe major parts of the clutch assembly need no maintenance or lubrication during normal service. However, all linkage parts need lubrication at points of contact. The linkage itself must be adjusted to prevent wear of the clutch disc.●Free-play AdjustmentYou can make only one adjustment on the clutch linkage —the free-play adjustment. Free play is the allowable space between the throwout bearing and the pressure plate release levers. This space is important because it prevents pressure on the levers that could keep the clutch from engaging fully. In other words, the throwout bearing must be slightly away from the pressure plate levers so that the bearing applies no pressure on the levers. On the other hand, there must not be too much freeplay between the bearing and the levers. With too much clearance, the clutch cannot fully disengaged when the driver press the clutch pedal to the floor. In most cases, you measure the free play at the clutch pedal, rather than at the bell housing.The free play allows some motion at the beginning of the clutch pedal travel, before the pedal meets resistance. Since the distance varies with the type of pressure plate, check the service manual. Usually, free play should be about 20 to 25mm.Free play can be adjusted at some point where the clutch linkage consists of threaded rods with locknuts. The rod closest to the clutch fork is the most common adjustment point. Begin by locating the rod and locknut beneath the vehicle. Then determine which way to turn the adjustment nuts to get the correct free play at the pedal. You can get a rough estimate of free play by moving the clutch fork to see if it still has some movement. The best way to make the adjustment is to loosen the locknut and move the adjustment nut a few turns. Then check the free play at the pedal. Continue making adjustments until you have the correct free play. When the free-play adjustment meets the manufacturer’s specification, tighten the locknut.Check the free-play adjustment every six months and make any adjustment. Clutches need adjustment that often, since free play decreases slightly as the clutch disc wears. However, the need for frequent adjustments means a problem in the clutch mechanism itself.There must be free play between the throwout bearing and pressure plate release levers. Problems can result from “riding the clutch”. A driver who rests one foot on the clutch pedal causes the throwout bearing to rub against the clutch release levers. As a result, the throwout bearing becomes worn quickly. Also, the clutch disc may wear out due to slippage because the parts are not fully engaged.●Clutch FaultsThe following are the main faults:Slip —failure of the surface to grip resulting in the driven plate revolving slower than the engine flywheel : Clutch gets hot and emits an odor.Spin or drag —failure of the plates to separate resulting in noise from thegearbox when selecting a gear: most noticeable when thevehicle is stationary.Judder —a vibration which occurs when the clutch is being engaged , i.e. when the vehicle is stationary.Fierceness —sudden departure of the vehicle even though the pedal is being released gradually.E The Clutches（supplementary contract）A clutch is a friction device used to connect and disconnect a driving force from a driven member. In automotive applications, it is used in conjunction with an engine flywheel to provide smooth engagement and disengagement of the engine and manual transmission.Since an internal combustion engine develops little power or torque at low rpm, it must gain speed before it will move the vehicle. However, if a rapidly rotating engine is suddenly connected to the drive line of a stationary vehicle, a violent shock will result.So gradual application of load, along with some slowing of engine speed , is needed to provide reasonable and comfortable starts. In vehicles equipped with a manual transmission, this is accomplished by means of a mechanical clutch.The clutch utilizes friction for its operation. The main parts of the clutch are a pressure plate, and a driven disk. The pressure plate is coupled with the flywheel, while the driven disk is fitted to the disk by the springs so that the torque is transmitted owing to friction forces from the engine to the input shaft of the transmission. Smooth engagement is ensured by slipping of the disk before a full pressure is applied.The automobiles are equipped with a dry spring-loaded clutch. The clutch is termed “dry”because the surfaces of the pressure plate and driven disks are dry in contrast to oil-bath clutches in which the plate and disks operate in a bath of oil. It is called “springloaded”because the pressure plate and the driven disk are always pressed to each other by springs and are released only for a time to shift gears or to brake the automobile.In addition to the plate and disk, the clutch includes a cover, release levers, a release yoke, pressure springs and a control linkage. The clutch cover is a steel stamping bolted to the flywheel. The release levers are secured inside the cover on the supporting bolts. The outer ends of the release levers are articulated to the pressure plate. Such a construction allows the pressure plate to approach the cover or move away from it, all the time rotating with the cover or move away from it, all the time rotating with the flywheel. The springs spaced around the circumference between the pressure plate and the clutch cover clamp the driven disk between the pressure plate and the flywheel.The springs are installed with the aid of projections and sockets provided on the cover and pressure plate. The pressure plate sockets have thermal-insulation gaskets for protecting the springs against overheating.The clutch release mechanism can be operated either mechanically or hydraulically. The mechanically-operated release mechanism consists of a pedal, a return spring, a shaft with lever, a rod m release yoke lever, a release yoke, a release ball bearing with support and a clutch release spring. When the clutch pedal is depressed, the rod and shaft with yoke shift the release bearing and support assembly. The release bearing presses the inner ends of the release levers, the pressure plate is moved away from the driven disk and the clutch is disengaged. To engage the clutch , the pedal is released, the release bearing and support assembly is shifted back by the return spring thus releasing the release levers so that the pressure plate is forced by its springs towards the flywheel to clamp the driven disk and engage the clutch.The clutch hydraulically-operated release mechanism consists of a clutch pedal , clutch release spring , a main cylinder , a pneumatic booster, pipelines and hoses and a lever of the clutch release yoke shaft. Time main cylinder accommodates a piston with a cup. The pneumatic booster serves to decrease the pedal force required disengage the clutch. The booster includes two housings with the servo diaphragm clamped in between. The housing accommodates pneumatic, hydraulic and servo plungers. When the clutch pedal is pushed, the fluid pressure from the main cylinder is transmitted through the pipelines and hoses to the hydraulic and servo plungers of the pneumaticbooster.The servo arrangement is intended for automatic change of the air pressure in the pneumatic cylinder proportionally to the force applied to the pedal. The plunger moves with the diaphragm, the outlet valve closes and the inlet valve opens thus admitting the compressed air to the pneumatic plunger piston. The forces created by the pneumatic and hydraulic plungers are added together and are applied through the push rod to the release yoke shaft lever; the lever turns the shaft and the release yoke, thus disengaging the clutch. After the clutch pedal is released, the outlet valve opens and the air from the cylinder is let out to the atmosphere.Automatic clutches were used in certain U.S. and European cars. American Motors’“E-Stick”clutch eliminated the need for physical operation of the clutch system called “Hydrak”, which consisted of a fluid flywheel connected to a single, dry disk clutch.In the “E-Stick” set up, the pressure plate levers “engage” the clutch disk rather than “release” them. Also, the clutch remains disengaged until a servo unit is applied by oil pressure when the shift lever is placed “in gear” with the engine running.The “Hydrak”unit also begins operation when the lever is “in gear”. This activates a booster unit, which disengages the clutch disk. The hydraulic clutch parts are bridged over by a free-wheel unit, which goes into action when the speed of the rear wheel is higher than the speed of the engine. A special device controls engagement of the mechanical clutch, depending on whether the rear axle is in traction or is pushed by car momentum.A more-or-les unusual clutch pressure plate set-up is used on late model Chrysler and American Motors cars. Called a semi-centrifugal clutch, the pressure plate has six cylindrical rollers which move outward under centrifugal force until they contact the cover. As engine speed increases, the rollers wedge themselves between the pressure plate and cover so that the faster the clutch rotates, the greater the pressure exerted on the pressure plate and disk.传动系统A基本传动系统的组成部份传动系统是将发动机动力转移到驱动轮的结构。
交通运输与物流专业中英文对照外文翻译文献
(文档含英文原文和中文翻译)中英文翻译税收和运输外部性摘要综述的运输外部控制税收的作用（资料评论到税收的作用在于控制交通运输的运营状况）。
它认为，运输税的设计应预先考虑到现有的税收扭曲经济的影响（设计运输税时应该考虑到现有税收对经济的负面影响），在决策者的处置运输手段的限制。
运输定价的公平考虑的相关性探讨。
引言对欧盟数据显示乘客驾驶汽车行驶的公里数，1999是1970的两点五倍,汽车驾驶占有的份额达到79%( 1970年74%)。
在美国汽车运输中，汽车运输比例甚至在总额行驶千米数占更高比例， (1998年是84%)。
在1999年，欧盟的75%货物运输(包括短程海运和航运) 是通过公路运输的。
而美国的30%是公路运输(欧洲委员会,2001)。
汽车和卡车的模式在各自的运输市场占据着大份额，这反应出出它们的特性，比如灵活性和舒适性。
然而，当家庭和企业决定是否需要进行一个旅行，什么时候进行，采取什么旅行模式和途径，他们只会把自己的成本和收益考虑进去。
与社会最优化相比，由此产生的交通需求太高。
它在集中在特殊时刻的日子，分享不同的模式时是次优的。
这是因为，总体上，每个额外的运输用户还会增加其他运输用户和社会成本。
在人们决策过程中，这些没有考虑进去的成本是外部成本。
这些交通运输主要的边际外部成本包括交通堵塞，交通意外，环境成本和路面损坏 (针对重型车辆)。
大多数这些外部性具有一个反馈效应的特性:外部本身的水平也会影响经济主体的行为。
最明显的例子是交通堵塞和交通事故。
时间的成本影响着客运和货运交通的需求。
同样的道理,事故的风险影响着运输需求,模式的选择、路线的选择和驾驶行为等等。
反馈效应影响也包括空气污染和噪音,因为这些将导致厌恶或减轻此行为。
政府可以利用一些工具来应对这些外因素。
总体来说,一个人可以区分定价、监管和基础设施政策。
最后一类非常广泛。
例如, 它不仅包括实体基础设施或虚拟基础设施膨胀的能力,但也包括空间规划。
《交通运输系统工程与信息》投稿须知
投稿须知《交通运输系统工程与信息》是中国科学技术协会主管、中国系统工程学会主办、交通运输系统工程专业委员会承办、中国科学出版社出版的一级科技学术期刊，国内外公开发行的双月刊。
2004年被国家科技部评定为“中国科技核心期刊”。
目前，本刊已被“EI Compendex美国《工程索引》”、“中国科学引文数据库（CSCD）”、“《中文核心期刊要目总览》（2011年版）（北京大学图书馆）”、“中国科技论文与引文数据库（CSTPCD）”收录，是“中国学术期刊综合评价数据库”来源期刊，同时已被《中国学术期刊文摘（CSAC）》、“中国核心期刊(遴选)数据库”、“中国知识资源总库（CNKI）”全文、“万方数据－数字化期刊群”全文、“中文科技期刊数据库”全文、“SCOPUS文摘引文数据库”收录。
本刊是面向交通运输系统、综合交通工程、智能交通工程、信息工程等学科、以传播新理论、新技术，探讨重大交通工程中的理论与实践问题、促进学术交流、推动学科发展为宗旨，坚持理论与实践、引进与创新相结合的方针，努力反映交通运输系统工程、智能交通与信息等领域的最新成就与世界交通运输科技的前沿动向，鼓励不同观点的争鸣。
本刊设有决策论坛、综合交通运输体系论坛、智能交通系统与信息技术、系统工程理论与方法、案例分析等栏目。
本刊不接收纸质稿和Email投稿，作者来搞请直接通过本刊主页(; ) 提交。
投稿要求：(1) 思想新颖、观点明确、数据真实可靠。
文章全文字数（包括摘要和参考文献）应控制在6 000字以内，对有价值的综述性文章，可8 000字左右.(2) 附中英文标题（20字以内），中英文标题下分别列出所有作者中英文姓名及工作单位（名称、所在省市及邮编）.(3) 首页脚注须分别列出：①基金项目名称（中英文）及项目编号（若有基金资助）；②第一作者简介，包括姓名、出生年、性别、籍贯、职称（职务）、学位；③通讯作者的E-mail地址（第一作者为在校学生须由其导师担任）.(4) 文章最后列出全部作者的姓名、单位、职称、学位、E-mail地址、手机号码、通信地址等.(5) 摘要是介绍文章主要内容和特色的概括性文字，包括：研究目的、研究方法、研究结果和研究结论等要素.中文摘要控制在250~300字.英文摘要与中文摘要一一对应，英文摘要时态:用一般现在时说明研究目的、叙述研究内容、描述结果、得出结论等；用一般过去时描述已做的工作。
智能物流系统中英文对照外文翻译文献
智能物流系统中英文对照外文翻译文献智能物流系统在现代物流行业中发挥着重要的作用。
本文翻译了一篇关于智能物流系统的外文文献，提供了中文和英文对照的版本。
Title: A Translation of Foreign Literature on Intelligent Logistics SystemsAbstract:Introduction:Main Body:1. Definition of Intelligent Logistics Systems- 中文：智能物流系统是指应用人工智能和物联网技术，对物流过程进行智能化管理和优化的系统。
- English: Intelligent logistics systems refer to systems that apply artificial intelligence and Internet of Things technologies to intelligently manage and optimize logistics processes.2. Key Features of Intelligent Logistics Systems- 中文：智能物流系统的主要特点包括即时监控、自动化处理和智能决策等。
- English: The key features of intelligent logistics systems include real-time monitoring, automated processing, and intelligent decision-making.3. Benefits of Intelligent Logistics Systems- 中文：智能物流系统的应用带来了许多好处，包括提高运输效率、降低成本和减少错误率等。
- English: The application of intelligent logistics systems brings numerous benefits, including improved transportation efficiency, cost reduction, and error rate reduction.Conclusion:This translation provides an insight into the concept, functions, and benefits of intelligent logistics systems. Understanding these aspects is essential in harnessing the potential of such systems in the logistics industry.Reference:[Insert reference to the original foreign literature here]以上为智能物流系统中英文对照外文翻译文献的简要内容翻译。
交通安全外文翻译文献中英文
外文文献翻译(含：英文原文及中文译文)英文原文POSSIBILITIES AND LIMITA TIONS OF ACCIDENT ANALYSISS.OppeAbstraetAccident statistics, especially collected at a national level are particularly useful for the description, monitoring and prognosis of accident developments, the detection of positive and negative safety developments, the definition of safety targets and the (product) evaluation of long term and large scale safety measures. The application of accident analysis is strongly limited for problem analysis, prospective and retrospective safety analysis on newly developed traffic systems or safety measures, as well as for (process) evaluation of special short term and small scale safety measures. There is an urgent need for the analysis of accidents in real time, in combination with background behavioural research. Automatic incident detection, combined with video recording of accidents may soon result in financially acceptable research. This type of research may eventually lead to a better understanding of the concept of risk in traffic and to well-established theories.Keyword: Consequences; purposes; describe; Limitations; concerned; Accident Analysis; possibilities1. Introduction.This paper is primarily based on personal experience concerning traffic safety, safety research and the role of accidents analysis in this research. These experiences resulted in rather philosophical opinions as well as more practical viewpoints on research methodology and statistical analysis. A number of these findings are published already elsewhere.From this lack of direct observation of accidents, a number of methodological problems arise, leading to continuous discussions about the interpretation of findings that cannot be tested directly. For a fruitful discussion of these methodological problems it is very informative to look at a real accident on video. It then turns out that most of the relevant information used to explain the accident will be missing in the accident record. In-depth studies also cannot recollect all the data that is necessary in order to test hypotheses about the occurrence of the accident. For a particular car-car accident, that was recorded on video at an urban intersection in the Netherlands, between a car coming from a minor road, colliding with a car on the major road, the following questions could be asked: Why did the driver of the car coming from the minor road, suddenly accelerate after coming almost to a stop and hit the side of the car from the left at the main road? Why was the approaching car not noticed? Was it because the driver was preoccupied with the two cars coming from the right and the gap before them that offered him thepossibility to cross? Did he look left before, but was his view possibly blocked by the green van parked at the corner? Certainly the traffic situation was not complicated. At the moment of the accident there were no bicyclists or pedestrians present to distract his attention at the regularly overcrowded intersection. The parked green van disappeared within five minutes, the two other cars that may have been important left without a trace. It is hardly possible to observe traffic behavior under the most relevant condition of an accident occurring, because accidents are very rare events, given the large number of trips. Given the new video equipment and the recent developments in automatic incident and accident detection, it becomes more and more realistic to collect such data at not too high costs. Additional to this type of data that is most essential for a good understanding of the risk increasing factors in traffic, it also important to look at normal traffic behavior as a reference base. The question about the possibilities and limitations of accident analysis is not lightly answered. We cannot speak unambiguously about accident analysis. Accident analysis covers a whole range of activities, each originating from a different background and based on different sources of information: national data banks, additional information from other sources, especially collected accident data, behavioral background data etc. To answer the question about the possibilities and limitations, we first have to look at the cycle of activities in the area of traffic safety. Some ofthese activities are mainly concerned with the safety management of the traffic system; some others are primarily research activities.The following steps should be distinguished:- detection of new or remaining safety problems;- description of the problem and its main characteristics;- the analysis of the problem, its causes and suggestions for improvement;- selection and implementation of safety measures;- evaluation of measures taken.Although this cycle can be carried out by the same person or group of persons, the problem has a different (political/managerial or scientific) background at each stage. We will describe the phases in which accident analysis is used. It is important to make this distinction. Many fruitless discussions about the method of analysis result from ignoring this distinction. Politicians, or road managers are not primarily interested in individual accidents. From their perspective accidents are often treated equally, because the total outcome is much more important than the whole chain of events leading to each individual accident. Therefore, each accident counts as one and they add up all together to a final safety result.Researchers are much more interested in the chain of events leading to an individual accident. They want to get detailed information abouteach accident, to detect its causes and the relevant conditions. The politician wants only those details that direct his actions. At the highest level this is the decrease in the total number of accidents. The main source of information is the national database and its statistical treatment. For him, accident analysis is looking at (subgroups of) accident numbers and their statistical fluctuations. This is the main stream of accident analysis as applied in the area of traffic safety. Therefore, we will first describe these aspects of accidents.2. The nature of accidents and their statistical characteristics.The basic notion is that accidents, whatever there cause, appear according to a chance process. Two simple assumptions are usually made to describe this process for (traffic) accidents:- the probability of an accident to occur is independent from the occurrence of previous accidents;-the occurrence of accidents is homogeneous in time.If these two assumptions hold, then accidents are Poisson distributed. The first assumption does not meet much criticism. Accidents are rare events and therefore not easily influenced by previous accidents. In some cases where there is a direct causal chain (e.g. , when a number of cars run into each other) the series of accidents may be regarded as one complicated accident with many cars involved.The assumption does not apply to casualties. Casualties are often related to the same accident andtherefore the independency assumption does not hold. The second assumption seems less obvious at first sight. The occurrence of accidents through time or on different locations are not equally likely. However, the assumption need not hold over long time periods. It is a rather theoretical assumption in its nature. If it holds for short periods of time, then it also holds for long periods, because the sum of Poisson distributed variables, even if their Poisson rates are different, is also Poisson distributed. The Poisson rate for the sum of these periods is then equal to the sum of the Poisson rates for these parts.The assumption that really counts for a comparison of (composite) situations, is whether two outcomes from an aggregation of situations in time and/or space, have a comparable mix of basic situations. E.g. , the comparison of the number of accidents on one particular day of the year, as compared to another day (the next day, or the same day of the next week etc.). If the conditions are assumed to be the same (same duration, same mix of traffic and situations, same weather conditions etc.) then the resulting numbers of accidents are the outcomes of the same Poisson process. This assumption can be tested by estimating the rate parameter on the basis of the two observed values (the estimate being the average of the two values). Probability theory can be used to compute the likelihood of the equality assumption, given the two observations and their mean.This statistical procedure is rather powerful. The Poisson assumptionis investigated many times and turns out to be supported by a vast body of empirical evidence. It has been applied in numerous situations to find out whether differences in observed numbers of accidents suggest real differences in safety. The main purpose of this procedure is to detect differences in safety. This may be a difference over time, or between different places or between different conditions. Such differences may guide the process of improvement. Because the main concern is to reduce the number of accidents, such an analysis may lead to the most promising areas for treatment. A necessary condition for the application of such a test is, that the numbers of accidents to be compared are large enough to show existing differences. In many local cases an application is not possible. Accident black-spot analysis is often hindered by this limitation, e.g., if such a test is applied to find out whether the number of accidents at a particular location is higher than average. The procedure described can also be used if the accidents are classified according to a number of characteristics to find promising safety targets. Not only with aggregation, but also with disaggregation the Poisson assumption holds, and the accident numbers can be tested against each other on the basis of the Poisson assumptions. Such a test is rather cumbersome, because for each particular case, i.e. for each different Poisson parameter, the probabilities for all possible outcomes must be computed to apply the test. In practice, this is not necessary when the numbers are large. Then the Poissondistribution can be approximated by a Normal distribution, with mean and variance equal to the Poisson parameter. Once the mean value and the variance of a Normal distribution are given, all tests can be rephrased in terms of the standard Normal distribution with zero mean and variance one. No computations are necessary any more, but test statistics can be drawn from tables.3. The use of accident statistics for traffic safety policy.The testing procedure described has its merits for those types of analysis that are based on the assumptions mentioned. The best example of such an application is the monitoring of safety for a country or region over a year, using the total number of accidents (eventually of a particular type, such as fatal accidents), in order to compare this number with the outcome of the year before. If sequences of accidents are given over several years, then trends in the developments can be detected and accident numbers predicted for following years. Once such a trend is established, then the value for the next year or years can be predicted, together with its error bounds. Deviations from a given trend can also be tested afterwards, and new actions planned. The most famous one is carried out by Smeed 1949. We will discuss this type of accident analysis in more detail later.(1). The application of the Chi-square test for interaction is generalised to higher order classifications. Foldvary and Lane (1974), inmeasuring the effect of compulsory wearing of seat belts, were among the first who applied the partitioning of the total Chi-square in values for the higher order interactions of four-way tables.(2). Tests are not restricted to overall effects, but Chi-square values can be decomposed regarding sub-hypotheses within the model. Also in the two-way table, the total Chisquare can be decomposed into interaction effects of part tables. The advantage of 1. and 2. over previous situations is, that large numbers of Chi-square tests on many interrelated (sub)tables and corresponding Chi-squares were replaced by one analysis with an exact portioning of one Chi-square.(3). More attention is put to parameter estimation. E.g., the partitioning of the Chi-square made it possible to test for linear or quadratic restraints on the row-parameters or for discontinuities in trends.(4). The unit of analysis is generalised from counts to weighted counts. This is especially advantageous for road safety analyses, where corrections for period of time, number of road users, number of locations or number of vehicle kilometres is often necessary. The last option is not found in many statistical packages. Andersen 1977 gives an example for road safety analysis in a two-way table. A computer programme WPM, developed for this type of analysis of multi-way tables, is available at SWOV (see: De Leeuw and Oppe 1976). The accident analysis at this level is not explanatory. It tries to detect safety problems that need specialattention. The basic information needed consists of accident numbers, to describe the total amount of unsafety, and exposure data to calculate risks and to find situations or (groups of) road users with a high level of risk. 4. Accident analysis for research purposes.Traffic safety research is concerned with the occurrence of accidents and their consequences. Therefore, one might say that the object of research is the accident. The researcher’s interest however is less focused at this final outcome itself, but much more at the process that results (or does not result) in accidents. Therefore, it is better to regard the critical event in traffic as his object of study. One of the major problems in the study of the traffic process that results in accidents is, that the actual occurrence is hardly ever observed by the researcher.Investigating a traffic accident, he will try to reconstruct the event from indirect sources such as the information given by the road users involved, or by eye-witnesses, about the circumstances, the characteristics of the vehicles, the road and the drivers. As such this is not unique in science, there are more examples of an indirect study of the object of research. However, a second difficulty is, that the object of research cannot be evoked. Systematic research by means of controlled experiments is only possible for aspects of the problem, not for the problem itself. The combination of indirect observation and lack of systematic control make it very difficult for the investigator to detectwhich factors, under what circumstances cause an accident. Although the researcher is primarily interested in the process leading to accidents, he has almost exclusively information about the consequences, the product of it, the accident. Furthermore, the context of accidents is complicated. Generally speaking, the following aspects can be distinguished: - Given the state of the traffic system, traffic volume and composition, the manoeuvres of the road users, their speeds, the weather conditions, the condition of the road, the vehicles, the road users and their interactions, accidents can or cannot be prevented.- Given an accident, also depending on a large number of factors, such as the speed and mass of vehicles, the collision angle, the protection of road users and their vulnerability, the location of impact etc., injuries are more or less severe or the material damage is more or less substantial. Although these aspects cannot be studied independently, from a theoretical point of view it has advantages to distinguish the number of situations in traffic that are potentially dangerous, from the probability of having an accident given such a potentially dangerous situation and also from the resulting outcome, given a particular accident.This conceptual framework is the general basis for the formulation of risk regarding the decisions of individual road users as well as the decisions of controllers at higher levels. In the mathematical formulation of risk we need an explicit description of our probability space, consistingof the elementary events (the situations) that may result in accidents, the probability for each type of event to end up in an accident, and finally the particular outcome, the loss, given that type of accident.A different approach is to look at combinations of accident characteristics, to find critical factors. This type of analysis may be carried out at the total group of accidents or at subgroups. The accident itself may be the unit of research, but also a road, a road location, a road design (e.g. a roundabout) etc.中文译文交通事故分析的可能性和局限性S.Oppe摘要交通事故的统计数字, 尤其国家一级的数据对监控和预测事故的发展, 积极或消极检测事故的发展, 以及对定义安全目标和评估工业安全特别有益。
物流 外文翻译 外文文献 英文文献 中国快递行业研究报告
2011年中国快递行业研究报告——China Express Delivery Industry Report, 2011 Enterprise wide USD $ 3300 Release Date Dec.2011AbstractIn July, 2011, in the “Twelfth Five-Year (2011-2015)” plan on the development of postal industry issued by State Post Bureau of the Peo ple’s Republic of China, the following “twelfth five-year” development indicators were put forward for the express delivery industry: the network coverage of key express delivery enterprises came up to 98% in municipalities and provincial capitals, and over 90% in provincially administered municipalities; and the key express delivery enterprises realized the 72-hour inter-provincial capital and inter-key city express delivery rate of more than 90%, express delay rate of lower than 0.8%, damage rate of lower than 0.01%, and loss rate of lower than 0.005%.The express delivery business of China has witnessed rapid growth in 2011. Up to the end of September of 2011, Chinese express delivery companies (with annual sales of over RMB5 million) had made 2.52 billion deliveries, up 53.3% year-on-year, and harvested RMB53.14 billion, a 28.9% YoY rise, of which Chinese inner-city express business revenue was RMB4.67 billion, with the year-on-year increase of 58.1%; the cross regional express business revenue rose 37% year-on-year to RMB30.73 billion; and the international and Hong Kong, Macao and Taiwan business revenue was RMB13.57 billion, a slight rise of 4.9% from the same period of last year.From January to September of 2011, 1.125 billion deliveries were made in Guangdong, Zhejiang and Shanghai, accounting for 44.64% of the national business volume, and achieved RMB25.697 billion with a 48.36% share of the total business revenue in China.‘Research report on the express delivery industry in China’ mainly covers the followings:The twelfth five-year plan of national express delivery industry and the twelfth five-year plan of express delivery industry in key provinces and cities;Development status, business classification,λ market structure, price and competition structure of the express delivery industry in China;Analysis on the express delivery industry in importantλprovinces and cities in Guangdong, Shanghai, Beijing and Jiangsu etc.Performance of UPS, FedEx, DHL and TNT in Chinese express deliveryλ market.Development history, corporate operation, SWOT analysis and marketλstrategy of 15 local express delivery enterprises (including EMS, China Sinotrans Group, China Railway Express, Air Express, SF Express, STO Express, ZJS Express, YTO Express, Yunda Express, ZTO Express, etc.)EMS：The revenue of China Post Group footed up to RMB189.9 billion in 2010, presenting an AAGR of 18.5% during the 11th Five-Year Plan (2006-2010); wherein, the proceeds of express business saw an average growth rate of 19.2%. Currently, EMS possesses 16 cargo aircrafts, 40 national airlines, 2 international airlines, more than 20 thousand transportation vehicles, 8 collecting and distributing centers and 31 provincial distribution centers.SF Express: its operating revenue has maintained high-speed growth since 2003, with an AAGR of over 40%; and the figure in 2010 registered RMB12 billion. In August, 2011, SF Express increased RMB400 million to reshuffle stock rights of SF Airlines whose air fleet covers two Boeing 757-200 All-Cargo Aircrafts and three Boeing 737-300 Aircrafts at present.ZJS Express: its operating performance has saw a comparatively slow rise since 2004, and it made negative growth affected by economic crisis during 2008-2009. However, the operating revenue of the company hit around RMB2 billion in 2010, soaring 66.7% from a year earlier and setting a new high record.In next a few years, e-commerce will further drive the steady and rapid growth of the express delivery industry, and the operating costs will rise ever and spur the price hike of express delivery. As the market expands, for considerable benefit, a growing number of companies in the express delivery sector will be merged and reorganized, and the businesses of express delivery firms will be increasingly differentiated.2011年中国快递行业研究报告——中国快递行业研究报告，2011企业广泛$ 3300美元的发行日期dec.2011摘要在七月，2011，在“第十二个五年（年）”计划对邮政产业发展的国家邮政局发行的中国人民共和国，以下“第十二五”发展指标提出了快递行业：网络覆盖的关键快递企业走到98%直辖市、省会城市，和90%多个省直管市；和关键快递企业实现72小时省际资本和inter-key快递率超过90%，表示延迟率低于0.8%，破损率低于0.01%，损失率低于0.005%。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
附件1：外文资料翻译译文北京运输系统摘要：运输系统提供了与城市郊区显着不同的服务，这通常会导致有关用户选择交通方式的不同假设。
本文所提到的仿真模型，提出了评估影响运输服务的政策。
运输方式被认为是公共交通工具，包括轻型轨道交通（轻轨）和公共汽车，加上私人轿车。
在三步旅行者行为仿真模型中，使用了广义运输成本的概念。
它提出各类交通以及对居民的出行选择和郊区住宅社区形态量化的建议，并使用了源自于中国北京一个典型走廊的数据。
仿真结果表明：票价降低，增加公共交通的综合能力，以及对私家车的惩罚是很有必要的，以此来提高系统效率和郊区的吸引力，特别是对那些低收入的人；没有公路定价，将鼓励中等收入居民转向私人轿车，同时,高收入者可能因为道路拥挤离开郊区；然而公共交通的改善可以吸引更多短距离和中距离的旅客，但轿车用户对于旅行距离并不敏感。
关键词：广义成本，公共交通，拥挤定价，运输服务，北京从上世纪90年代，中国大中城市已经历郊区化，而且这些城市的空间结构逐步形成，在很大程度上依赖于交通运输的进步。
由于人口爆炸和改造中心城市，许多郊区城镇发展为住宅区，这些新发展城镇的大部分居民受雇于中心城市或附近的工业区。
例如，80%多回龙关郊区社区的居民在北京或发达地区中心城市工作，几乎有一半的北京社区居民受雇于朝阳区中央商务区。
这些领域在交通系统规划与提供经营效率方面对交通政策制定者和城市规划设计师提出了新的挑战。
在许多情况下，边沿城镇通过高速公路和城市轨道连接中心城市或工业园区。
相比传统的城市，郊区展览更稳定的运输使用模式，更加依赖公共交通，私人汽车，较少使用机动模式（自行车，步行）。
工作距离比任何单一因素对人们的交通方式的影响都大。
这样的特点，可以深刻影响的人口郊区化，并限制一些人移民到郊区。
本文利用西北地区的北京作为一个测试案例，分析了运输服务的政策，主要是费用和服务质量，将影响整体运输系统与城市空间结构。
本文的组织如下：第二节简要回顾最近一些有关运输方式选择的文献，并与海城市海城走廊案件，特别是中国的现状进行比较。
第三部分讨论广义运输成本的概念，并建立了新的概念，包括利用广义成本和转移成本预算的障碍。
第四节在公共运输和驾驶之间介绍旅客运输方式选择行为仿真模型，然后转向注意中国经验运输服务政策与海城市海城出行方式选择。
在第五节中，特别提到的情况是，利用北京的轻轨和高速公路，西北地区迅速郊区化。
在第六节中，得出主要研究结果和政策启示。
大量的研究机构在研究运输方式和个体出行方式的选择。
一般来说，有三种常见的方法来确定这个问题。
第一部分着重研究影响选择决策的每个模式的特点，所采用的实证研究状况用于改变结果，研究人与旅游目的等。
例如，travel-to-work 行为在阿克拉（加纳）主要由知觉服务品质、商业通勤车以及员工的个人情况决定，而不是通过访问，等待时间或车载。
在英国，为了走亲访友而决定行程，经济因素在很大程度上解释模式的选择，使用私人交通工具时定性的理由往往是次要的（科恩、哈里斯，1998）。
约翰松等使用瑞典上班者的图片案例表明了灵活性和舒适性这两个感觉影响个人的选择模式。
根据在法兰克福，德国的实验领域研究和统计分析，认为有四类人。
一类人很少重视金钱和时间因素，第二种人非常重视金钱但很不重视时间，第三种人都重视，第四种人很少重视金钱但很重视时间。
林坦库等人选自来自1998年的数据，即荷兰国家旅游调查组确认空间配置，土地利用和交通基础设施，对长途旅行模式比如通勤，商务和休闲旅行具有重大影响。
广义运输成本的概念经常用于评估和解释的旅游行为。
广义旅行成本包括旅行时间，超过时间，金钱成本，停车收费，和一些令人忽视的小费。
然而，这一概念在不同的文献因为不同的研究目的是不同的。
例如，广义骑自行车费用如下：旅行时间，物理需要，舒适，交通安全，自行车被盗的风险，停放自行车的费用以及维护费用，个人安全。
货币化的广义概念通常是将旅行时间转换成货币费用，增加的费用，收取的费用，在这项研究中，模拟通勤出行行为，三个运输关于概念费用是相通的。
第一个可以被定义为预算障碍，包括经营费用，养路费以及停车场收费。
第二个是货币化的广义成本和时间成本，包括经营费用，以及停车费用。
用户被假定为尽量减少个人的货币化成本，把自己的出行方有别于旅行时间和费用成本。
广义货币化成本的公共交通是计算访问到火车站的时间，等候时间，这是计算的基础上的进展，等车时间，以及票价。
货币化费用包括旅行时间，收费，汽车运行成本和在工作地方的停车场收费。
第三个概念是确定模式转移成本即拥挤造成不适的成本。
据推测，如果乘客在车辆已远远超过容量，新来的旅客会转移到其他负担得起的运输方式。
贯穿城市及乡村的公路通常是不仅仅可以通私人轿车，也可以通公共汽车。
介于以前的经验，道路定价可以大大提高用户的剩余地区，公共交通的费用可以大大减少因长时间的旅行而造成的拥挤，特别是，如果用户很大程度上钟情于公共交通。
方案2表明高收入的旅客不得不放弃定期迁移到郊区的计划，主要由于免费使用的情况下所造成的严重挤塞。
另一组是深深影响了中等收入的旅客，她他们从公共运输方式换成了私家车驾驶。
公共汽车票价降低和公交线路的增加使得许多中等收入居民转移去坐公交车，同时小汽车用户转移到轻轨，特别是那些短距离旅行。
此外，研究发现，一个综合改善公共交通服务和一些私人汽车惩罚措施的政策，有利于提高系统效率和郊区社区的吸引力。
这种综合系统包括轻轨、公共汽车票价的降低，服务质量的提高和公路通行费的征收。
应该指出，轻轨已旨在增加公交扶手使公共交通更吸引用户，从而，减少道路拥挤。
根据模拟结果，轻铁及巴士票价减少以及客容量的增加，使这一模式对于那些中低收入旅行者更有吸引力。
最后的结果是，越来越多的人移民到郊区，不论是低收入到高收入阶层。
当然，公共交通服务的改善需要政府补贴，这也是一个世界性的现象。
每个模式的经济旅行距离几乎不受不同的运输服务的政策影响。
公共汽车是用于短距离的旅行，而中、长距离者喜欢轻铁。
反之，小汽车用户则是无所谓。
结果表明，这些低收入公民因现有运输服务的政策限制迁移到郊区的经济房屋，包括相对高收费的公共交通和公路，以及有限的轻轨和公交线路。
当然，所有运输模式对于在家工作的人在一定程度上都有影响。
城市交通在整个世界中都是是政府政策的一个主要领域。
运输政策也会影响城市形态，尤其是郊区化。
在北京，许多经济公寓是专为那些低收入居民建造准备的。
在重大问题的决策之前有两个主要的问题。
首先，从过去的经验，大量在郊区社区中的永久居民都是中等或更高收入的人。
而且很多的业主仍然居住在城市中心，郊区房子只用来去度假。
此外，居民不断投诉交通拥堵和相对高的收费公路，特别是在繁忙时间。
本研究的模拟结果解释了这些现象并尝试给出了相应的政策含义。
附件2：外文原文Transport systemAbstractTransport systems offer substantially different services in city-suburb areas; this usually leads to different assumptions about user behavior in transport mode choice. In this paper a simulation model is proposed to assess the effect of transport service policies on mode choice. The transport modes considered are public transport, including light rail transit (LRT) and bus, together with the private auto.In the three step traveler behaviour simulation model, the concept of generalised transport costs is used. Various transit incentives are proposed and their impacts on residents travel choice and suburban residential community form are quantified, using data on a typical city-suburb corridor in Beijing, China.The simulation results show that: the fare reduction and capacity increase of public transport integrated with private car disincentives is necessary to improve system efficiency and suburb community attractiveness, particularly for those low income people; without highway pricing, medium income residents will be encouraged to shift to private car while more high income persons might leave the suburb because of road congestion; public transport improvement can attract more short and medium distance travelers, but the car users are not sensitive to travel distance.Keywords: generalised cost, public transport, congestion pricing, transport service, BeijingFrom the middle of 1990s, metropolitans in China have been experiencing suburbanization, and the spatial structures of these cities are shaped, in large measure, by the advances of transportation. Many suburban towns were development only for residential areas because of the population explosion and renovation in central cities. Most of the residents in these new development towns are employed in the central city or near industrial parks. For example, more than 80% residents of Hui long guan suburban community in Beijing have jobs in central city or developed CBD areas. And almost half of the residents in Wangjing community are employed in CBD in Chaoyang District. These areas present new challenges for transport policy makers and urban planning designers to plan and operate efficient transportation systems.In many cases the edge towns are connected to the central city or industrial parks by high-speed highways and urban rails. Compared to traditional urban areas, the suburban towns exhibit more stable transport mode use, more reliance on public transport and private automobile, less use of non-motorized modes (bicycle, walking). Home to work distances have a stronger bearing on people’s transport mode to work than anysingle factor. Such characteristics can deeply influence the population suburbanization, and restrict some people from immigrating to the suburb.This paper analyses how the transport service policy, mainly fare and service quality, will impact the overall transport system performance and urban spatial structure, using the North-west area of Beijing as a test case. The paper is organized as follows. Section II briefly reviews some of the recent literatures on transport mode choice, and compares these studies with the city-suburban corrid or cases, especially the current conditions in China. Section III discusses the concept of generalised transport costs, and establishes the new concepts including budget barrier, monetized generalised cost and shift cost. Section IV presents the traveler behaviour simulation model of transport mode choice between public transport and driving. Attention is then turned to the Chinese experience of transport service policy and city-suburban travel mode choice in section V, with special reference to the case of North-west area which is a rapidly suburbanized region served by light rail and highway in Beijing. Major findings of the research and the policy implications are concluded and discussed in section Ⅵ.A substantial body of research exists on transport mode and individual travel mode choice. In general, there are three common approaches to identify this issue. The first part of researches focuses on determining the characteristics of each mode which influence the choice decision. The results change with the adopted empirical case condition, studied person and travel purpose, etc. For example, travel-to-work behavior in Accra (Ghana) is influenced mainly by perceived service quality of the commercial commuter vehicles as well as employees' personal circumstances rather than by access, waiting or in-vehicle times (Abane, 1993). For trips made to visit friends and relatives in Britain, the economic reasons largely explain mode choice, and qualitative reasons for using private transport are often secondary (Cohen and Harris, 1998). Vredin Johansson et el. used a sample of Swedish commuters to prove that both attitudes towards flexibility and comfort influencing the individual's choice of mode (Vredin Johansson, Heldt et al., 2006).Based on an experimental field study and statistical analysis conducted in Frankfurt Main, Germany, four classes of individuals were identifed. One class allocates a low importance to both monetary and time considerations, the second allocates high importance to money and low importance to time, the third allocates high importance to both, and the fourth allocates a low importance to money and a high importance to time (Davidov, Yang-Hansen etal., 2006). And Limtanakool etel. employed data from the 1998 Netherlands National Travel Survey to confirm the spatial configuration of land use and transport infrastructure has a significant impact on mode choice processes for medium and long distance trips for all purposes: commute, business, and leisure trips Generalised transport costs is a concept frequently used forassessing and explaining travel behaviour. The generalised costs of travel include the travel time, excess time, money cost, parking charge, and the discomfort and lesser connivance. However, this concept is diverse in different literatures for varying research purposes. For example, the generalised costs of cycling are the following: travel time, physical needs, comfort, traffic safety, risk of bicycle theft, costs of parking bicycles and maintenance costs, personal security. And the concept of monetized generalised cost isusually calculated by converting travel time into monetary cost, and adding the cost of the fare charged In this study, for simulating the commuter’s travel behaviour, three transport costs related concepts are adopted in order. The first can be defined as budget barrier, including the fare or toll charged together with parking cost which all means cash payment in the trip. The second one is monetized generalized cost including fare, parking and time cost. Users are assumed to minimize individual monetized generalized trip cost and divide themselves among the travel modes that are differentiated in travel time and fare cost. The monetized generalized costs of public transport is computed as a function of the access time to the station, the waiting time which is calculated based on the line’s headway, in-vehicle travel time, and the fare. The monetized generalized cost of driving includes travel time, toll, car operation cost and parking charge in work place. The third concept is identified as mode shift cost which means discomfort cost caused by congestion. It is assumed that if the passengers in vehicle have far exceeded the capacity, the new coming passenger will shift to other affordable transport mode.The city-suburb highway is usually used not only by private auto, but the bus. Using the previous experience，road pricing can greatly increase users’ surplus in the area where the cost of public transport can be significantly reduced by decreasing congestion because of the long travel distances involved, Particularly, if a substantial portion of users are captive to public transport. The results of scenario 2 show that more high income travelers have to abandon the plan of migrating to suburb mainly owing to the serious congestion on the condition of free use. Another deeply influenced group is medium income travelers who shift from public transport modes to car driving.Bus fare reduction and bus lines increase make many medium income residents shift to bus transport, meanwhile the car users shift to light rail, particularly those who travel for short distances. Furthermore, the research finds that an integrated policy of improved public transport service and some private car disincentives is beneficial to improve system efficiency and suburb community attractiveness.The integration consists of light rail and bus fare reduction, service quality improvement and highway toll imposition. It should be pointed out that light rail has been designed to increase transit rider ship by making public transport more attractive to users and, thus, to reduce road congestion. According to the simulation result, the light rail and bus fare reduction and capacity increase makes this mode more attractive to those low and medium income travelers who are captive to bus mode before. The final outcome is that more people can migrant to the suburb, from low to high income classes. Of course, the public transport service improvement requires government subsidization, which is a worldwide phenomenon. The economic travel distance of each mode is almost not affected by different transport service policies. Bus is used more by short distance traveler, while the medium and long distance commuters prefer to light rail. On the contrary, car users are not sensitive to the travel distance, as shown in figure 3-4. The result indicates that those low income citizens are restricted from migrating to economic houses in suburb towns on account of existing transport service policies, including relatively high fare of public transport and highway, limited light rail capacity and bus lines. Of course, all transport modes have been affected to some degree by the numbers of persons working at home.Urban transportation is a major realm of government po1icy throughout the world. The transport policies also will affect the urban form deeply, especially during suburbanization. In Beijing, many economic apartments have been constructed in suburb for those low income citizens. There are two major problems before the policy makers. First, from the past experience, a large number of the permanent residents in the suburban communities are medium or even high income people. And many of the house owners still reside in central city and go to their suburban house only for holiday. In addition, the residents continually complain at the transport congestion and relative high toll of highway, particularly at peak time. The results of simulation in this study explain these phenomena and try to give some policy implications.。