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81.
Within the realm of urban logistics, Macário (2013) developed a hypothesis, denominated the Logistics Profile (LP) concept that suggests homogeneous groups of urban zones with respect to three dimensions, which could be used to analyze freight movement policy: (1) the social and built environment; (2) characteristics of the goods/products being moved; (3) characteristics of the deliveries at the receiver establishment. The concept was expected to ease the transferability of best practices in city logistics, by analyzing similarities and differences between zones. This research uses a quantitative methodology to apply the LP concept, and assess its potential, using the city of Lisbon as a case study. The analysis is focused on: (a) the extrapolation of freight trip generation per establishment and delivery characteristics from a sample of commercial establishments to the population within the case study, (b) proposing a methodology to test the LPs, (c) testing the existence of proposed LPs. Freight trips have been extrapolated using a Multiple Classification Analysis (MCA) model. Freight delivery characteristics were attributed to establishments from a sample-based probability distribution. LPs were tested using a two-step cluster analysis. Some LPs have been matched with clusters of case-study zones, subject to case study particularities. Profile overlap was not an issue and occurrences were expected. The testing showed that Logistic Profiles have the potential for being used as a departure point for urban freight planning and policy analysis. 相似文献
82.
Do the determinants of service and pricing on “regional” routes – linking towns and smaller cities to main trunk routes and/or to each other – differ from the established results from the literature? We study all flights (about 3000) on all regional routes (about 250) with scheduled airline service from one of about 130 regional towns or cities, in regional airline markets in six countries: Australia, Canada, New Zealand, Norway, Sweden, and a sample of three U.S. states which closely resemble the other regions studied. For each flight we have observations on up to five prices offered at different times before flight date. We also have equipment type and social-economic data. Overall, our results give qualified support to the standard gravity model of the extent of service between city pairs, though with two interesting differences: operators on regional routes have greater flexibility in the size of aircraft they can deploy, which results in a finer-grained variability of service offerings and, the presence of competition on regional routes has a large effect on the total supply of seats. We are able to successfully estimate a well-specified airfare model, which shows strong effects of competition on prices, quite substantial intertemporal price discrimination, and interesting differences between regional and main trunk route pricing. 相似文献
83.
[目的]空心村的形成和发展受到众多因素的影响,包括经济因素、自然因素、社会因素、户籍和社保制度,以及管理和规划因素等。由于我国的自然地理和区域发展差异悬殊,不同地形区空心村发展的主要影响因素各不相同。文章探究在复杂地形条件下,交通因素对丘陵沟壑区空心村的产生和发展所产生的影响。[方法]以陕西省澄城县为例,通过实地调查、走访农户、搜集资料等方法,利用交通便利指数、交通距离指数等开展分析,综合考虑了道路崎岖程度、道路质量状况以及经济发展水平等,对研究区的农村空心化现象进行了研究。[结果]崎岖的道路极大地增加了居民的出行成本和时间,不利于农村的基础设施建设和发展;在当前的社会经济条件下,黄土丘陵沟壑区农村的交通便利程度与村庄空心化程度呈现一定的负相关性,即交通条件越好,村庄的空心化程度越低。[结论]在黄土丘陵沟壑区开展空心村整治工程时,可以优先考虑交通条件较差、相对偏远的地区。 相似文献
84.
Kenneth Amaechi Agu Vincent Chidi Enemuo Linda Oge Okoye Okechukwu Onwuasoigwe 《International journal of injury control and safety promotion》2017,24(4):487-492
Studies from parts of Nigeria reported low compliance with seatbelt. This study sought to establish driver seatbelt use in Enugu, Nigeria by gender, vehicle type/use and time of day. Observations were done day and night at randomly selected locations. Data were analysed with SPSS version 15. Differences in response were checked with chi-square for trend. Confidence interval was 95% and P value < 0.05 was regarded as significant. Average compliance was 37.6% for the 510 males (85%) and 90 females (15%) observed. It was 74.8% in the day and 0.3% at night. Among males, 218 (42.7%) wore seatbelt while 9 (10%) females did. For commercial drivers 159 (65.2%) complied while 68 (19.1%) private drivers did. Truck drivers had 100% compliance while sports utility vehicle drivers had the lowest (18.8%). There is poor seatbelt compliance in Enugu, Nigeria and need for educational campaigns and stricter enforcement. 相似文献
85.
Due to the shortage of cargo aircraft, Chinese express companies have to provide transportation services with a hybrid method that consists of “rented bellies and self-owned cargo aircraft”. Because the bellies are rented from air passenger companies and because the cargo aircraft are owned by the express companies, it is important for the express companies to use their cargo aircraft as effectively as possible. This paper constructs a bi-level model to optimize the flight transportation network of an express company. The upper model designs the network and allocates the transportation capacity with the objective of minimizing the total transportation cost, and the lower model calculates the link flows in user equilibrium. Data from ShunFeng (SF) Express Company (China) are used to conduct the case study. Using the model outputs, the flows on links and at nodes are analyzed to illustrate the transportation and transshipment situations. 相似文献
86.
Analyzing the impact of intermodal-related risk to the design and management of biofuel supply chain
This study presents a mathematical model that designs a reliable multi-modal transportation network for a biofuel supply chain system, where intermodal hubs are subject to site-dependent probabilistic disruptions. The disruption probabilities of intermodal hubs are estimated by using a probabilistic model which is developed using real world data. We developed an accelerated Benders decomposition algorithm to solve this challenging NP-hard problem. Numerical analysis show that the model selects to use intermodal hubs located in areas with low disruption probabilities. In case of a disaster, the reliable solution results in 6.21% savings over the minimum cost solution. 相似文献
87.
88.
George Yannis Eleonora Papadimitriou Petros Evgenikos Anastasios Dragomanovits 《International journal of injury control and safety promotion》2016,23(4):373-387
The paper presents the findings of a research project aiming to quantify and subsequently classify several infrastructure-related road safety measures, based on the international experience attained through extensive and selected literature review and additionally on a full consultation process including questionnaire surveys addressed to experts and relevant workshops. Initially, a review of selected research reports was carried out and an exhaustive list of road safety infrastructure investments covering all types of infrastructure was compiled. Individual investments were classified according to the infrastructure investment area and the type of investment and were thereafter analysed on the basis of key safety components. These investments were subsequently ranked in relation to their safety effects and implementation costs and on the basis of this ranking, a set of five most promising investments was selected for an in-depth analysis. The results suggest that the overall cost effectiveness of a road safety infrastructure investment is not always in direct correlation with the safety effect and is recommended that cost–benefit ratios and safety effects are always examined in conjunction with each other in order to identify the optimum solution for a specific road safety problem in specific conditions and with specific objectives. 相似文献
89.
Dongyoun Shin 《International journal of urban and regional research》2016,40(5):1044-1060
The research on which this essay is based sought to provide a deeper understanding of live urban activities. The main idea was to obtain in‐depth trip information by integrating sensing technology with crowdsourcing‐based methods. Location and acceleration sensors embedded in smartphones can deliver useful trip information. Research had previously been conducted to find an accurate data analysis algorithm for high‐level data mining, an efficient sensing method for power saving. As a proof of concept, this essay presents a case study of Zurich that successfully implemented previous research achievements in the real environment. It established that urban travel behaviour can, in fact, be collected by sensors embedded in mobile devices, and that the data thus obtained can be used to measure the characteristics of trip behaviour in cities by means of an advanced classifying algorithm and analysis. The strength of this research is its pioneering role in clearing the ground for future urban data collection methods and planning strategies. Specifically, this study could provide answers to the following key questions: How can crowdsourcing be applied to the collection of urban transportation data? What kinds of information can be extracted from the crowdsourced mobile sensing platform? What kinds of knowledge, within the transportation domain, can be derived from the above? 相似文献
90.
This paper suggests a flexible decision support framework for the strategic planning of a freight transport hub network in Greece. The proposed methodology treats practical aspects related to the optimal number, location and geographical covering of hubs, through the network analysis of interregional trade, based on original survey data for road freight flows during 2004–2012. The results offer insights into the hierarchical structure of the network and related investment priorities, as the hub role of a prefecture is found to be strongly influenced by high population densities and manufacturing specialization, and its location along highway corridors. 相似文献