地铁车站出入口设施优化设置研究

闸机检票效率影响地铁车站的整体通行能力,且作用于乘客等待时间来影响社会效益。为此,从系统优化的角度出发,以稳态条件下单位时间总费用为目标函数,通过研究北京西直门地铁枢纽A口客流出入站的过程,分析影响闸机设置的因素,以客流需求、空间限制、成本投入、疏散要求等为约束条件,采用线性规划的方法,对闸机设置进行优化研究,分别确定普通闸机与加宽闸机的个数。根据优化结果,为科学组织高峰小时客流出入车站提供基础数据和重要参考,检验实设闸机的合理程度。     

Hub location in the South-Atlantic airline market: A spatial competition game

The paper analyzes the airlines’ hub location problem through a spatial competition game played in two stages. First, airlines sequentially choose the location of their hub and second, they compete offering direct or connecting services between each city-pair. Different outcomes in the first stage will affect competition in the second, and as a consequence, the market share that airlines can obtain.Given actual demand patterns, results of the model are applied to the South-Atlantic airline market. We study the subgame perfect equilibriums obtained as a result of competition in each city-pair to anticipate where airlines will probably locate their hubs once an “open skies” policy is adopted in this market.     

The impact of compliance measures on the operation of a bus system: The case of Transantiago

In a regulated bus system operated by private companies, pecuniary incentives can be of primary importance to ensure the quality of the operation and the level of service, especially when there are only a few companies and basically no competition among them. The case of Transantiago, in the capital city of Chile, provides a good example of this. The very ambitious Transantiago project, implemented in 2007 in Santiago, integrated the bus and the subway systems, changing the route structure of the bus services, introducing a common and integrated fare system and electronic payment device, and tendering the operation of approximately 4,600 buses (which by the launch of the system in February 2007 had increased to 5600) to 10 private companies replacing some 4000 small operators which owned 8000 buses. In the beginning, the system faced huge difficulties. Operators' revenue formula basically consisted of a fixed payment, which changed slightly with the actual patronage. This quickly turned out to be a problem, and as technological support became available (several months after the launch), compliance measures were implemented, directly affecting the operators' revenue. The first measure considered the seat/standing places per hour of the buses in operation, for each company, and compared it to the theoretical figure. As a result, buses operating during peak hours increased from 4600 to 5600 in just two months. Subsequent indexes included service frequency and regularity, as well as effective bus-km, aggregated by company first and later by service. This paper shows how the successive implementation of these performance indexes had an impact on the operation of Transantiago in the first years, discusses the difficulties faced to implement them and highlights the importance of technological support to make possible the application of adequate compliance measures.     

Market Orientation in Public Transport Research—A Review

It is commonly argued that, in order to meet increasing competition, public transport organizations and systems need to be market oriented. Even though the notion of market orientationhas not been explicitly addressed in public transport research, studies relevant to market orientation have been conducted. The aim of this paper is to introduce the concept of market orientation into the field of public transport, to review previous research into market orientation in public transport research, and to suggest directions for future research. Market orientation is defined as the generation and dissemination of market intelligence by organizations, as well as responses to it. The review suggests that previous academic research has focused on intelligence generation by developing and using models for measuring travel behaviour, stated preferences, perceived customer quality, and satisfaction. Studies of responsiveness have mainly addressed the physical improvements made in public transport organizations, which is also the primary concern of the industry research accounted for. There has been less research into the dissemination of market intelligence, the drivers of market orientation, the relations between the elements, and the overall concept of market orientation in public transport. It is thus concluded that future public transport research needs to address these issues.     

Assessment of Cross‐Border Spillover Effects of National Transport Infrastructure Plans: An Accessibility Approach

Abstract

Traditional transport infrastructure assessment methodologies rarely include the full range of strategic benefits for the transportation system. One of these benefits is the contribution to cross‐border integration, critical for the European integration process. However, this is a key issue in strategic planning and decision‐making processes, as its inclusion may increase the probability of large‐scale transport infrastructure projects being funded. This paper presents a methodology for the measurement of the contribution of transport infrastructure plans to European integration. The methodology is based on the measurement of the improvement in network efficiency in cross‐border regions of neighbouring countries, via accessibility calculations in a Geographical Information System support. The methodology was tested by applying it to the ambitious road and rail network extensions included in the Spanish Strategic Transport and Infrastructure Plan (PEIT) 2005–2020. The results show significant and important network efficiency improvements of the PEIT outside the Spanish border. For the road mode, while the Spanish average accessibility improvement accounts for 2.6%, average improvements in cross‐border regions of France and Portugal are of 1.8%. And for the rail mode, the corresponding Spanish value is 34.5%, whereas in neighbouring regions it accounts for 20.2%. These results stress the significant importance of this strategic benefit and the consequent need for its inclusion in strategic planning processes. Finally, the paper identifies the potential of the methodology when applied at different administrative levels, such as the local or state levels.     

Lightweight Occupancy Estimation on Freeways Using Extended Floating Car Data

Advanced traffic management systems rely heavily on technology to perform accurate estimations of the current state of the traffic as well as its short-term evolution. The objectives are improving traffic flow and enhancing road safety. Their success is based on accurate monitoring of two key variables, specifically speed and occupancy. The latter of the two has, to date, received significantly less attention from the scientific community. In this work we present a lightweight method to perform “on-line” occupancy estimation. We first propose three occupancy measurements calculated from data collected by a floating car: vehicle count, percentage of stop time, and headway. We then extend these discrete values to a continuous estimation of occupancy in space and time. The proposed estimators are based on a pairwise linear regression of each of the previously calculated measurements over certain references obtained from other floating cars or magnetic loop detectors. The method has been calibrated and validated under real traffic conditions and data. Despite the ease of implementation, the method is able to reproduce the occupancy values generated by the actual loop detectors, achieving promising results, with estimation errors down to 6.52%, even before multivehicle systems are considered.     

免疫抑制因子对宫颈癌患者来源的树突状细胞的体外作用

目的　观察白细胞介素 10 (IL 10 )及血管内皮生长因子 (VEGF)对宫颈癌患者来源的树突状细胞 (DC)的体外抑制作用。方法　培养宫颈癌患者自体DC的小牛血清体系中加入粒 -巨噬细胞集落刺激因子 (GM CSF)、IL 4和肿瘤坏死因子 α(TNF α) ;流式细胞术检测免疫表型 ;甲基噻唑蓝法 (MTT)法检测异体混和淋巴细胞反应 (MLR)和细胞毒实验 ;酶联免疫吸附实验 (ELISA)法检测培养细胞上清液中IL 10和VEGF含量。结果　 10例宫颈癌患者外周血单个核细胞培养 10d后 ,获得 (40± 2 0 ) %的DC ,此类DC共刺激分子的表达减低 ,刺激自体T细胞杀伤癌细胞能力不足 ,分泌IL 10及VEGF的含量却升高。结论　IL 10和VEGF抑制了宫颈癌患者自体DC的功能。     

Modelling bicycle use intention: the role of perceptions

Users’ perceptions are identified as key elements to understand bicycle use, whose election cannot be explained with usual mobility variables and socio-economic characteristics. A hybrid model is proposed to model the intention of bicycle use; it combines a structural equations model that captures intentions and a choice model. The framework is applied to a case of a university campus in Madrid that is studying a new internal bike system. Results show that four latent variables (convenience, pro-bike, physical determinants and external restrictions) help explaining intention to use bike, representing a number of factors that are linked to individual perceptions.     

Using best–worst scaling to identify barriers to walkability: a study of Porto Alegre,Brazil

This paper pursues three goals: (1) determining the relative importance of built environment barriers limiting walkability, (2) analyzing the existence of an asymmetry in the way people evaluate positive and negative built environment characteristics, and (3) identifying solutions to tackle the main barriers and quantify their impact in walkability. A best–worst scaling survey was developed to compare the importance of eight different attributes of the built environment regarding walkability. Model results show an asymmetry negative–positive in the judgment and choice of built environment characteristics that promote and impede walkability. The most important barriers, obtained from worst responses, are connectivity, topography, sidewalk surface and absence of policemen. Walkability scores were computed for different neighbourhoods and different policy scenarios were forecasted. Simulation results from the worst responses indicate that improvements in sidewalk quality, along with an increase in the number of police officers, lead to an 85% increase in the walkability score for the lower income neighbourhoods.