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131.
Fixed-rail metro (or ‘subway’) infrastructure is generally unable to provide access to all parts of the city grid. Consequently, feeder bus lines are an integral component of urban mass transit systems. While passengers prefer a seamless transfer between these two distinct transportation services, each service’s operations are subject to a different set of factors that contribute to metro-bus transfer delay. Previous attempts to understand transfer delay were limited by the availability of tools to measure the time and cost associated with passengers’ transfer experience. This paper uses data from smart card systems, an emerging technology that automatically collects passenger trip data, to understand transfer delay. The primary objective of this study is to use smart card data to derive a reproducible methodology that isolates high priority transfer points between the metro system and its feeder-bus systems. The paper outlines a methodology to identify transfer transactions in the smart card dataset, estimate bus headways without the aid of geographic location information, estimate three components of the total transfer time (walking time, waiting time, and delay time), and isolate high-priority transfer pairs. The paper uses smart card data from Nanjing, China as a case study. The results isolate eight high priority metro-bus transfer pairs in the Nanjing metro system and finally, offers several targeted measures to improve transfer efficiency. 相似文献
132.
国外计算机网络技术在现代战争中发挥着越来越重要的作用。文章介绍了计算机网络技术的发展历程以及装备的研制、改进情况,指出了在现代战争中发展计算机网络技术的优势和重要性,重点探讨了几种计算机网络技术的性能及其特点,并论述了计算机网络技术的发展动向与分析。 相似文献
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通过分析CFG桩施工质量控制存在的问题,详细介绍了CFG桩施工参数自动记录仪的原理、性能、使用方法以及在京沪高速铁路李窑路基CFG桩试验段的应用效果. 相似文献
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136.
This paper derives the mathematical expressions for the transit time of cargo through a liner shipping network. Main efforts are devoted to deriving the calculation expressions of the connection time of cargo during trans-shipment. For the forward and many-to-one trans-shipment policies, we conduct a minor correction towards the expressions in existing studies to improve the completeness. Meanwhile, we propose an alternative but more straightforward calculation method for connection time which bypasses the complicated inductive argument in existing studies. Then we introduce two new trans-shipment policies: backward trans-shipment and one-to-many trans-shipment, and mathematically calculate the corresponding connection times. Numerical experiments also deliver some managerial insights into the effectiveness of backward trans-shipment in transit time control. 相似文献
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139.
As intelligent transportation systems (ITS) approach the realm of widespread deployment, there is an increasing need to robustly capture the variability of link travel time in real-time to generate reliable predictions of real-time traffic conditions. This study proposes an adaptive information fusion model to predict the short-term link travel time distribution by iteratively combining past information on link travel time on the current day with the real-time link travel time information available at discrete time points. The past link travel time information is represented as a discrete distribution. The real-time link travel time is represented as a range, and is characterized using information quality in terms of information accuracy and time delay. A nonlinear programming formulation is used to specify the adaptive information fusion model to update the short-term link travel time distribution by focusing on information quality. The model adapts good information by weighing it higher while shielding the effects of bad information by reducing its weight. Numerical experiments suggest that the proposed model adequately represents the short-term link travel time distribution in terms of accuracy and robustness, while ensuring consistency with ambient traffic flow conditions. Further, they illustrate that the mean of a representative short-term travel time distribution is not necessarily a good tracking indicator of the actual (ground truth) time-dependent travel time on that link. Parametric sensitivity analysis illustrates that information accuracy significantly influences the model, and dominates the effects of time delay and the consistency constraint parameter. The proposed information fusion model bridges key methodological gaps in the ITS deployment context related to information fusion and the need for short-term travel time distributions. 相似文献
140.
Julie Paquette François Bellavance Jean-François Cordeau Gilbert Laporte 《Transportation》2012,39(3):539-564
In many countries, dial-a-ride services are provided by public authorities to elderly and handicapped people who cannot use
regular transit. Cost minimization is key to running these services, but one can observe a growing interest in quality measurement
and improvement. A first step in improving quality is to define a quality measurement scale specific to dial-a-ride services.
A second step is to incorporate quality measurements in mathematical models that serve as a basis for optimization algorithms.
To this end, an extensive survey of dial-a-ride users was conducted in Longueuil, the largest suburb of Montreal, Canada.
This paper describes the steps of the survey and presents its main conclusions: (1) 56 attributes were identified based on
interviews, (2) the questionnaire developed has proved to be reliable and valid, (3) an exploratory factor analysis allowed
us to determine 13 dimensions of quality in dial-a-ride services, (4) the most important criteria for users were identified,
and (5) population segmenting variables by which subgroups of users can be categorized were also determined. Managerial implications
of our results are also discussed. 相似文献