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Abstract

The economics literature offers many examples of studies of the economic impact of transportation infrastructure such as highways, ports, and airports; however, little attention has been paid to other types of infrastructure such as logistics platforms. This article is a first assessment of the economic effects of the largest logistics platform in Europe – PLAZA, the Zaragoza Logistics Platform – located in Spain. More precisely, this paper analyzes the economic significance of PLAZA on the economy of the Aragon region where it is located. The methodology is based on the application of input–output analysis to the final demand of logistics platform-based companies in a manner that is similar to well-established studies of the economic impacts of tourism on tourist expenditure. This makes it possible to quantify the various levels of economic effects (direct, indirect, and induced) in terms of jobs, salaries, and wages, turnover, gross operating surplus (GOS), and gross value added (GVA). The conclusions reveal the economic importance PLAZA has for the regional economy of Aragon, representing just over 2% of total GVA and 3% of turnover.  相似文献   
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Transportation - Urban growth originates multiscale spatial patterns, such as those of transportation networks. Here, the public transportation network (PTN) of the city of Lisbon is analysed from...  相似文献   
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This paper outlines an approach to complex spatio-temporal marine ecosystem modelling as applied to the North Western European Continental Shelf. The model presented here combines an eddy-permitting (approximately 6 km horizontal resolution) baroclinic model, the Proudman Oceanographic Laboratory Coastal Ocean Modelling System (POLCOMS), with the European Regional Seas Ecosystem Model (ERSEM). This has been run within an operational framework using operationally available high resolution atmospheric and lateral boundary forcing, allowing hindcast and near-real time nowcast simulations to be performed. The modelled surface temperature and chlorophyll distributions are presented, and interannual variations discussed. Validation of both the physical and ecosystem submodels show the system to be effective, whilst highlighting areas where improvements in the system can be made. Distinct regional differences in predictive skill are shown. The system presented is ready for operational implementation to provide products and services for use both scientifically and in coastal zone and shelf seas management activities. A programme of work to update the system is already in place.  相似文献   
4.
The steerability and stability of vehicles must be maintained during emergency stopping and evasive driving maneuvers on degraded road surfaces. The introduction of antilock brake and traction control systems (ABS/TCS) has expanded the envelope of safe vehicle operation for the majority of drivers. These mechatronic systems combine an electronic controller with wheel speed sensors, an electro-mechanical hydraulic brake actuator, and in some instances, engine intervention through the engine control unit, to regulate wheel slip. The development of ABS systems has traditionally depended on extensive in-vehicle testing, at cold weather proving grounds, which contribute to lengthy product development cycles. However, recent attention has been focused on the use of simulation and hardware-in-the-loop strategies to emulate test conditions in a controlled setting to shorten product design time and methodically address critical safety issues. In this paper, the effect of transient load shifting due to cargo movement on ABS performance in light-duty vehicles will be investigated. Analytical and empirical mathematical models are presented to describe the chassis, tire/road interface, wheel, brake modulator, and cargo dynamics. Two strategies, a model-free table lookup and model-based discrete nonlinear controller, are presented to regulate the ABS modulator's operation. These vehicle and controller dynamics have been integrated into a simulation tool to investigate the effect of transient weight transfers on the vehicle's overall stopping distance and time. Representative numerical results are presented and discussed to quantify the ABS systems' performance for various loading and operating conditions.  相似文献   
5.
Gordon Mills 《运输评论》2013,33(3):337-352

For the light-rail line that opened in Montpellier in late 2000, this study describes the urban setting, the previous bus services, the reasons for choosing light rail, the procedures for evaluation and approval, the chosen route, and the arrangements for funding, construction and operation. The Montpellier case shows how a bus-way can be a step on the path to light-rail. Among other conclusions, the study highlights the scope for light-rail to yield reduced journey times for public transport users, and to effect environmental improvement; the case for building a tramway is strengthened if complementary urban developments are in hand.  相似文献   
6.
The ability of conventional South African travel analysis practices to analyse adequately the travel needs of the poor is examined. The origins and nature of conventional practices are described, and it is observed that typically their scope has been limited to motorized modes, commutes and peaks. The paper reports on the findings of an activity diary survey administered in Cape Town that extended the conventional scope of analysis. An activity‐based survey method was selected because it typically yields higher rates of trip recall than other methods and is therefore relatively well suited to investigating travel behaviour in its fuller complexity. Selected findings of the survey are presented to demonstrate that travel occurring by non‐motorized modes, for non‐work purposes and during off‐peak periods, is considerable. It is argued that the conventional limitation in analytical scope can create serious misconceptions of the true nature of travel behaviour, particularly of low‐income households. By restricting the focus of analysis to motorized, work and peak period trip‐making, there is a risk of a routine bias being introduced in the way the urban passenger transport problem is understood, and in the nature of the interventions that are implemented as a result.  相似文献   
7.
In this paper, the combined power management/design optimization problem is investigated for a fuel cell/Liion battery PHEV. Formulated as a constrained multi-objective optimization problem (MOP), the combined optimization problem simultaneously minimizes the vehicle cost and fuel consumption subject to the vehicle performance requirements. With an emphasis on developing a generic optimization algorithm to find the Pareto front for the synthesized MOP, the Pareto based multi-objective particle swarm optimization (PMOPSO) algorithm is developed, which solely depends on the concept of Pareto dominance. Three approaches are introduced to the PMOPSO method to address the constrained MOP. They are: (i) by incorporating system constraints in the original objective functions, the constrained MOP is transformed to an unconstrained MOP; (ii) to avoid being trapped in local minima, a disturbance operator with a decaying mutation possibility is introduced; (iii) to generate a sparsely distributed Pareto front, the concept of crowding distance is utilized to determine the global guidance for the particles. Finally, under the Matlab/Simulink software environment, simulation results are presented to demonstrate the effectiveness of the PMOPSO in the derivation of the true Pareto front.  相似文献   
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