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491.
Hörcher  Daniel  Graham  Daniel J. 《Transportation》2021,48(5):2521-2544
Transportation - The paper studies a general bidirectional public transport line along which demand varies by line section. The length of line sections also varies, and therefore their contribution...  相似文献   
492.
Arnesen  Petter  Malmin  Olav Kåre  Dahl  Erlend 《Transportation》2020,47(5):2415-2437
Transportation - Speed prediction of different transport modes is important in applications such as route planning, transport modelling and energy calculations. In this paper we model bicycle speed...  相似文献   
493.
Sakai  Takanori  Bhavathrathan  B. K.  Alho  André  Hyodo  Tetsuro  Ben-Akiva  Moshe 《Transportation》2020,47(2):997-1025

Freight forecasting models have been significantly improved in recent years, especially in the field of goods vehicle behavior modeling. On the other hand, the improvements to commodity flow modeling, which provide inputs for goods vehicle simulations, were limited. Contributing to this component in urban freight modeling systems, we propose an error component logit mixture model for matching a receiver to a supplier that considers two-layers in supplier selection: distribution channels and specific suppliers. The distribution channel is an important element in freight modeling, as the type of distribution channel is relevant to various aspects of shipments and vehicle trips. The model is estimated using the data from the Tokyo Metropolitan Freight Survey. We demonstrate how typical establishment survey data (i.e. establishment and outbound shipment records) can be used to develop the model. The model captures the correlation structure of potential suppliers defined by business function and provides insights on the differences in the supplier choice by distribution channel. The reproducibility tests confirm the validity of the proposed approach, which is currently integrated into a metropolitan-scale agent-based freight modeling system, for practical use.

  相似文献   
494.
Fully autonomous vehicles (AVs) have the potential to considerably change urban mobility in the future. This study simulates potential AV operating scenarios in the Greater Toronto Area (GTA), Canada, and assesses transportation system performance on a regional level. For each scenario, the base capacities of certain types of road links are modified to simulate the theoretical increase in throughput enabled by AV driving behavior. Another scenario examines driverless parking operations in downtown Toronto. Simulation results indicate that the increased attractiveness of freeways relative to other routes leads to slightly increased average travel distance as vehicles divert to access higher capacity road links. Average travel time is found to decrease by up to one-fifth at the 90% AV market penetration level. Concurrently, localized increases in congestion suggest that proactive transportation planning will be needed to mitigate negative consequences of AV adoption, especially in relation to induced demand for personal automobile travel.  相似文献   
495.
The Enhanced Variable Rate Codec (EVRC) is a standard for the Speech Service Opti6n 3 for Wideband Spread Spectrum Digital System, which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS (Personal Communications Systems). This paper investigated the combination of turbo codes with Unequal Error Protection (UEP) and 16-QAM modulation for EVRC codec of Rate 1 to get power and bandwidth efficient coding scheme. The results show that the UEP system outperforms the Equal Error Protection (EEP) one by 1.45dB at BER of 10^-5.  相似文献   
496.
Objective To map a mouse deafness gene.identify the underlying mutation and develop a mouse model for human deafncss.Methods Genetic lindage cross and genome scan wer used to map a novel mutation named hypoplasia of the membranous labyrinth (hml),which causes hearing loss in mutant mice.Results ① hml was mapped on mouse Chr 10 (~43 cM from the centromere) suggests that the homologous human gene is on 12q22--q24, which was defined on the basis of known mouse-human homologies (OMIM,2004). ② This study has generated 25 polymorphic microsateUite markers, placed 3 known human genes in the correct order in a high-resolution mouse map and narrowed the hml candidate gene region to a 500 kb area.  相似文献   
497.
Metal injection moulding (MIM) is a new technology to manufacture small intricate parts in large quantity. Numerical simulation plays an important role in its development. To predict the specific segregation effect in MIM injection, mixture theory is adopted to model the injection flow by a bi-phasic model. This model conducts to the solution of two-coupled Stokes equations. It is an extremely computational consuming solution in the scope of the traditional algorithms, which induce a serious challenge to cost-effectivity of the MIM simulation. Referred to some methods proposed by Lewis in mono-phasic simulation and the implicit algorithms in MIM simulation, a new explicit algorithm is proposed and realized to perform efficiently this type of bi-phasic flow. Numerically this algorithm is devised to perform the simulation in a fully uncoupled manner except for a global solution of the pressure field in each time step. The physical coupling is taken into account in a sequential pattern by fractional steps. This special algorithm does not need any iteration, so it is straightforward and robust, suitable for MIM simulation and other sorts of simulations for multi-phasic flow.  相似文献   
498.
���߽�ͨ���ź��Ż�����:�ع���ǰհ   总被引:2,自引:0,他引:2  
概括地回顾了一些关于离线(或脱机)交通信号灯优化设计的方法.其中包括用于在孤立交叉口的单点和区域性的联动控制系统.离线方法在设计时一般利用已有调查出来的交通数据作为固定的输入资料,这个跟实时设计方法所要求的从感应器即时检浏出来的情况作为设计依据是有本质上的区别.但一般沿用的信号配时设计方法都需要依靠已刻在行车线道上(允许通行)的方向指示标志为设计基础,但这个方向指示在确定后在整个优化过程中是维持不变的,这就限制了交通流量在线道上的分布,从而大大减低配时的灵活性,在这样情况下优化出来的结果肯定不会是最好的.直至近期,以行车线道为基本单位的配时设计方法(英文名称为Lane-based method;中文可称为线道法)发展起来.这个方法是由传统的Phase-based method(相位法)所演变出来的.线道法不但包含所有相位法的特点,而且更能为原本受约束的线道和配时设计进行全面优化.线道法可在单点交叉口和区域性的联动控制系统上应用.文末提出一些未来研究发展的新方向.  相似文献   
499.
���зֲ�����Ϣ��ģ��   总被引:2,自引:1,他引:2  
熵最大化方法被广泛应用于交通规划,为交通需求预测模型提供了理论依据.本文使用信息论中的熵概念描述居民出行分布,并根据最大信息熵理论提出了基于原点矩典型特征量约束条件下的出行分布模型,详细阐述了模型中各个参数的实际含义,该模型是一个普适性模型,其具体形式决定于最高阶原点矩阶数的取值,此值对模型精度及参数标定难易程度有重要影响.为确定模型参数,提出了实用的参数标定方法.由于模型中原点矩的最高阶数对模型精度有较大影响,为找到两者之间的关系,利用长春市出行调查数据研究了四种出行方式分别时应于五种原点矩最高阶数的模型拟合情况.因文中所建立的模型是一系列模型,为比较其描述问题的优劣差异,按照最大信息熵原理给出了确定系统分布的熵方法,并运用该方法对前述模型进行了比较.调查数据的验证结果表明,出行分布的信息熵模型可以正确地描述出行分布规律,熵方法可以简单有效地评价不同模型对同一问题描述的优劣差异.本文提出的熵模型和熵方法对城市交通规划具有指导意义.  相似文献   
500.
MULTIPLETRANS-ACTINGFACTORSMEDIATETHEINDUCTIONOFC-FOSINVASCULARSMOOTHMUSCLECELLSChenYanqun;BartekRydzewski,AllenJ.Naftilan(De...  相似文献   
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