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131.
132.
Regional passenger rail services are prevalent in France, as opposed to the more marginal role they play elsewhere in the world. It is indeed at the regional level that reforms have been successfully implemented, probably because the process was gradual and cautious. Initially in 1997, seven regions began experimenting with a decentralized system of regional passenger transportation services. By 2002, all metropolitan regions, with the exception of Corsica and Ile-de-France, were involved. Today we have reached a point where this process can be retrospectively and prospectively assessed. This article is first a retrospective assessment of the role of actors and the emerging dynamic between regional passenger rail transport supply and demand. Then, a prospective evaluation is offered since regionalization is best understood as an ongoing learning process that can be discontinuous or continuous. 相似文献
133.
Becky P. Y. Loo 《Transportation》2007,34(4):471-486
Paratransit refers to urban transport services “somewhere between private passenger transport and conventional public transport in terms of cost and quality of service” [Rimmer (1980), Paratransit: A commentary. Environ. Plan. A 12, 937–944]. Since the 1980s, a new form of paratransit—residents’ coach, which provides exclusive transport services to residents living in private housing estates—has emerged in Hong Kong. What was the background underlying the emergence and subsequent growth of residents’ coach services? Also, what was the role of residents’ coach in the public transport system of Hong Kong? With the completion of more railway extensions, should residents’ coach services be replaced? If so, what are the potential impacts on people’s life? This paper addresses the above research questions through a large-scale questionnaire survey that examined not only people’s modal choice but also their residential choice, socio-economic background and attitudes. The findings suggest that transport policy makers should pay more attention to examine new forms of paratransit and the ways of integrating them into the overall public transport system, both spatially and temporally. It is only through the development of an efficient and multi-modal transport system can the maximum potential of paratransit in filling the transport gap between conventional mass transit and private cars be realized. 相似文献
134.
依托台—忻线在忻府区城北铁路和公路立交勘察设计工程,运用指标分析的方法,综合考虑了建设条件、工程规模及投资、经济评价、环境影响、土地占用等因素,进行了技术方案比选,提出了切实可行的方案,并进行了经济评价和敏感性分析。研究表明:推荐方案为最佳方案,本项目具有良好的国民经济效益,并具备一定的抗风险能力,为解决类似的公铁立交设计方案提供有价值的参考。 相似文献
135.
随着大城市路网建设的逐渐稳定,服务水平评价结果成为城市交通管理决策的一个重要依据,因而对城市道路交通服务水平(LOS)的评价成为一项重中之重的研究内容. 本文提出一种基于模糊积分的区域交通LOS评价模型. 该模型能够解决区域交通服务水平中多路段评价结果复合时的非可加性问题,即区域交通服务水平不等于局部路段或路口服务水平的简单之和,可满足区域交通的评价需求. 在现场海量实测数据集的基础上,利用模糊积分用微观评价数值计算中观评价结果,排除了主观约束,并选取北京市典型区域进行了实验和应用,取得了较好的评价结果. 相似文献
136.
Y. S. Kim E. Y. Kim Y. W. Shin S. K. Lee 《International Journal of Automotive Technology》2010,11(5):759-765
This paper presents a multi-body flexible dynamic analysis of a centrifugal turbo blower for a fuel cell electric vehicle
(FCEV) based on the application of computer-aided engineering (CAE) to predict the acceleration at the mount position of the
blower. This predicted acceleration is validated by using the measured acceleration data. The numerical simulation for the
multi-body flexible dynamics of the blower is used not only to identify the most effective mount among four mounts in an FCEV
by controlling the complex stiffness of the isolator, but also to suggest the range of complex stiffness of the isolator at
the most effective mount. This numerical simulation technology can be useful for the estimation of the variation of vibration
transmission for the structural modification of the turbo blower. 相似文献
137.
The importance of vehicle safety cannot be exaggerated in today’s mobile societies. Many manufacturers, associates related
to vehicles and universities make an effort to improve vehicle safety by developing new technologies, applying high strength
steel to the body structure etc. However, the majority of these efforts are focused on decreasing injury. It is absolutely
important to minimize injury, but a more important aspect is coping with vehicle accidents. That is, As undeniably important
as it is to minimize potential injuries, it is critical that experts focus on developing ways to keep drivers out of situations
likely to lead to crashes in the first place. The purpose of this paper is to determine what the most critical factor is when
coping with an unfamiliar driving situation. The answer is to provide a wide-open field of vision, especially for the driver.
The driver’s field of vision is obstructed by the vehicle’s A-pillar. To solve this, the A-pillar obstruction angle, which
is the angle between the driver’s eyes and the A-pillar should be decreased. This paper purposes three-methods for decreasing
this angle structurally and applying a slim A-pillar which is as the best solution to decrease the A-pillar obstruction angle
and ensure the drivers field of vision at the same time 相似文献
138.
H. J. Kim B. Han W. S. Hong W. H. Shin G. B. Cho Y. K. Lee Y. J. Kim 《International Journal of Automotive Technology》2010,11(4):447-453
A 3000 cc diesel engine attached to an engine dynamo was used to test three newly developed electrostatic Diesel Particulate
matter filtration Systems (DPS 1, 2, and 3) under four steady-state engine operating conditions: idle, 2000 rpm with no load,
and 2000 rpm under 25% and 50% loads. Of the two developed alternatives, DPS 1 and DPS 2, DPS 2 comprises an ionization section,
electrostatic field additional section and Flow-Through Filter (FTF), which achieved almost 90% removal of particulate matter
(PM) under the engine’s operating conditions, and the efficiency of the FTF was maintained between 20% and 50%. Comparing
the long-term performance of DPS 2 and DPS 3 (effectively a serial combination of two DPS 2s) with a commercially-available
Diesel Particulate Filter (DPF), the DPS 2 and DPS 3 achieved almost the same efficiency for removing PM as the DPF but had
significantly improved (75%∼90% lower) differential pressure drops. 相似文献
139.
G. -Q. Liu Y. -C. Yan J. Chen F. -F. Xu 《International Journal of Automotive Technology》2010,11(4):573-580
A hydraulic power-assist system is a hydraulic regeneration system that can significantly improve fuel economy when installed
on a conventional bus operating in urban traffic. This paper presents a methodology for matching a new hydraulic power-assist
system (HPA) to a conventional bus. The HPA and the conventional bus were modeled using the AMESim environment. The HPA was
optimized using a simulation-based orthogonal design method with two indexes, the fuel economy and the acceleration performance.
According to the simulation results, the volume of the accumulator was the primary factor affecting fuel economy, and the
gear ratio of the transfer case was the primary factor influencing the acceleration performance. As a result, tradeoffs between
the two indexes are required for a practical operational scenario. Experimental results demonstrated that the optimal HPA
installed on a conventional bus was able to satisfy the acceleration performance requirement of the vehicle and also reduced
fuel consumption by 25 percent. 相似文献
140.
Fault detection method for electric parking brake (EPB) systems with sensorless estimation using current ripples 总被引:1,自引:0,他引:1
C. W. Lee H. B. Chung Y. O. Lee C. C. Chung Y. S. Son P. Yoon 《International Journal of Automotive Technology》2010,11(3):387-394
A fault detection method with parity equations is proposed in this paper. Due to its low cost implementation, the velocity
of the motor is not measurable in electric parking brake (EPB) systems. Therefore, residuals are not reliable when estimating
the motor velocity with a low-resolution encoder. In this paper, we propose a fault detection method with sensorless estimation
using current ripples that estimates the position and velocity of the motor by detecting periodical oscillations of the armature
current caused by rotor slots. In addition, this method can estimate the position and velocity of the motor with less computational
effort than a state observer. Moreover, the method is less sensitive to motor parameters than model-based estimation methods.
The effectiveness of this method is validated with experimental data, and the simulation results show that various faults
have their own residual patterns. Therefore, we can detect the presence of faults by monitoring the residual signals. 相似文献