关键词：汽车；管理维护；交通成本

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It is very important to obtain an ideal basic shape with optimal aerody namic characteristics in the auto-body styling design based on the whole shape optimization.Through obtaining the solutions for conflict problem in the auto-body styling aerodynamic design cooperating extension engineering, a variable cross-section method based on aero dynamic theoretical model to obtain ideal basic shape for car body is proposed.A theory model based on aerodynamics is developed.In addition, a generation method for a series of ideal basic bodies with favorable aerodynamic characteristics is developed, which enables the generation of these basic bodies by a variable cross-section method.This method is finally realized and it is shown in the evaluation that it is a new way for the auto-body styling design based on whole shape optimization.

关键词：汽车；车身形状；截面

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This paper introduces the effect of track wheel in rolling test of railway vehicle and puts forward a method of moment of inertia check based on inertia matching. According to coupled vibration between track wheel and wheel of car, normal modal analysis was proposed in this paper using FEM of PATRAN/NA-STRAN. Through analyzing, the result of first 10-order model was obtained. The analysis shows that the first inherent vibration frequency is 12.634 Hz. In this frequency and corresponding speed of 257 km/h of railway vehicle in the rolling test, the coupled vibration occurred between track wheel and wheel. During the test, avoiding running in 257 km/h for a long time will be useful for test precision.

关键词：汽车；模态分析；履带

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Parking facilities are important to the construction and development of urban central commercial district. With the increase of urban economy and people's living standards, more and more cars, followed by more and more city parking is not convenient. Especially in the city center business district, "parking difficult" problem is particularly serious. In order to solve the parking problem, Yuan Yang-Cheng in T city commercial district is taken as the object, according to the investigation on the parking behavior. The survey results show that the key factors affecting the behavior of parking is price and the parking is interested in the convenient parking of parking guidance system. Also, the reasonable use of price lever parking supply and demand has great room for adjustment.

关键词：汽车；停车问题；城市中心

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In this research, the feasibility of using mobile traffic sensors for binary vehicle classification on arterial roads is investigated. Features (e.g. speed related, acceleration/deceleration related, etc.) are extracted from vehicle traces (passenger cars, trucks) collected from real world arterial roads. Machine learning techniques such as support vector machines (SVM) are developed to distinguish passenger cars from trucks using these features. To address privacy concerns, classification is conducted using long vehicle traces and short vehicle traces separately. For classification using long traces, the proportions of accelerations and decelerations larger than 1mpss and the standard deviations of accelerations and decelerations are the most effective features. By classifying general trucks from passenger cars, the average misclassification rate for the best 4-feature SVM model is about 1.6% for the training data, and 4.2% for the testing data. For classification using short traces, it is necessary to define multiple types of traces and analyze them case-by-case. It was found that particularly for the turning movement traces, features such as average speed, standard deviation of speed, maximum acceleration/deceleration and standard deviation of acceleration/deceleration are fairly effective to classify vehicles. The misclassification rate for the best SVM classifier using short traces is about 14.8% for the stop-and-go traffic, and 15.6% for the non-stopped traffic.

关键词：汽车；汽车分类；传感器

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We set up one cylinder of CNG engine by using GT-Power software and the compression ratio and the knock are studied.The conclusions are as follows:when the compression ratio increases,the rate of pressure rise of acute burning period increases; The maximum cylinder pressure increases;The maximum temperature decreased slightly and after burning period the temperature increases;The critical knocking compression ratio appears at the full load of 4000rpm conditions; If we only consider it knocking or not,the engine compression ratios can change from 10 to 11.

关键词：汽车；发动机；仿真分析

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A template of pre-crash scenarios is presented to depict national crash statistics and kinematic information of time-to-collision for the design of appropriate crash countermeasures based on vehicle-to-vehicle (V2V) communications. This template serves the development of functional requirements, performance specifications, test procedures, and benefits estimation for potential light-vehicle V2V safety applications. A set of ten pre-crash scenarios is suggested as a priority list to be addressed by V2V technology for light vehicles (i.e., passenger cars, vans and minivans, sport utility vehicles, and light pickup trucks with gross vehicle weight ratings of 10,000 pounds or less). This report presents the time-to-collision equations as well as the crash statistics for each of the ten priority scenarios based on data available in the General Estimates System, National Motor Vehicle Crash Causation Survey, and Event Data Recorder databases.

关键词：汽车；安全通信；撞车

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This paper presents an analysis of the degree of willingness to change from motorized travel modes to walking or cycling. The aim of the analysis is to reduce uncertainty between stated willingness to change and real shifts from car or transit to nonmotorized transportation modes. Data were collected in the city of Valencia, Spain, through a novel data collection effort based on multiple survey methods. Respondents traveling by car or transit were asked about their willingness to change to walking or cycling under the implementation of improvement measures to be selected. Then a hypothetical scenario was presented to respondents who stated a willingness to change; in the scenario, the previously selected measures were implemented and respondents were supposed to be cycling or walking. In addition, the costs of their usual travel mode were gradually reduced until they gave up cycling or walking. Those who decided to keep on walking or cycling were assumed to have a strong willingness to change. A statistical analysis performed with Heckman's sample selection model permitted identification of demographic, socioeconomic, and travel-related factors influencing the degree of willingness to change. Results revealed that car users presented a stronger willingness to switch to walking or cycling than transit users. In addition, older respondents showed a stronger willingness to change to both walking and cycling. Work- and school-related journeys were less associated with walking than noncommuting journeys, but they were more related to cycling. Policy implications of the results are highlighted.

关键词：汽车；意愿评估；模式选择

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A passenger vehicle is a motor vehicle weighing less than 10,000 pounds and includes passenger cars and light trucks (pickup trucks, vans, SUVs, and other light trucks). Passenger vehicles make up over 90 percent of registered vehicles, and account for nearly 90 percent of total vehicle miles traveled (VMT). In 2011 there were an estimated 9,291,000 vehicles involved in police-reported crashes, 96 percent (8,953,000) of which were passenger vehicles. There were 43,917 vehicles involved in fatal crashes, of which 78 percent (34,182) were passenger vehicles. More than 21,000 passenger vehicle occupants lost their lives in traffic crashes in 2011, and an estimated 1.97 million were injured. From 2002 to 2011, passenger vehicle registrations increased 12 percent. Light trucks (LTVs) experienced a 27-percent increase in registrations, while passenger cars had an increase of 3 percent. Among the light-truck categories, pickup truck registrations increased 14 percent and van registrations decreased 6 percent; however, SUV registrations increased by 72 percent.

关键词：汽车；载客汽车；交通安全

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关键词：汽车；交叉研究；交通安全

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