排序方式: 共有57条查询结果,搜索用时 31 毫秒
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Ana C. Paixão Casaca 《Maritime Policy and Management》2013,40(3):203-208
The establishment and implementation of a training programme requires a training needs assessment (TNA). Without this approach, more often than not, training programmes have failed to succeed and to make such an assessment the instructional designer, i.e. the person in charge for this work, needs to follow a methodology. Unlike the other industries, the port industry has neglected the use of these methodologies, which is shown by the lack of research work published in academic journals. With a view to fill the existing gap, the paper proposes a five-step TNA methodology to be used in the port industry and applies its first three steps to investigate the port training situation in the new European Union member states. To achieve this objective, the paper is structured in the following way: Section 1 puts the research work into context; section 2 addresses the role of ports; section 3. presents a port TNA methodology; section 4. explains research methodology; section 5 addresses port training issues in the new European-member states; and section 6 presents conclusions and further comments. 相似文献
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José Manuel Vassallo Pablo Pérez De Villar Ramón Muñoz‐Raskin Tomás Serebrisky 《运输评论》2013,33(2):261-278
Abstract Public transport policy in the Madrid Metropolitan Area is often deemed as a success. In 1985, an important reform was carried out in order to create a new administrative authority to coordinate all public transport modes and establish a single fare for all of them. This reform prompted a huge growth in public transport usage, even though it reduced the funding coverage ratio of the transport system. Since then, Madrid’s public transport system has been undergoing an increasing level of subsidization, which might jeopardize the financial viability of the city public transport system in the future. In this paper, we present a detailed analysis of the evolution of the public transport funding policy in Madrid in recent years. We found that the increasing level of subsidy can hardly be explained on the basis of equity issues. Moreover, we claim that there is still room for a funding policy that makes the efficiency of the system compatible with its financial sustainability. 相似文献
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AbstractThe transition phase is generally defined as the process of switching from one timing plan to another; this process may include changes in offset, phase split or cycle length until coordination for a new timing plan is reached once again. As noted in the literature, transition phases between timing plans may lead to severe disruptions of traffic flow, resulting in potentially lasting effects. The aim of this paper is to comprehensively review, classify and analyse the literature regarding transition between different timing plans to highlight existing research gaps and give researchers a starting point to continue contributing with solutions to the transition problem. Regarding transition approaches, a gap concerning mathematical approaches was deemed significant as a transition could be greatly benefited by simultaneously optimising more than one operational measure of effectiveness through multi-objective mathematical models. Moreover, in the analysis of applied approaches, Shortway algorithms generally outperformed other practical methods under different scenarios. 相似文献
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Ana Laverón-Simavilla Victoria Lapuerta Sebastián Franchini Angel Sanz 《Journal of Marine Science and Technology》2008,13(3):190-206
A study of a boat's motion is carried out in order to analyze the aerodynamic properties of the optimal sail for obtaining
the maximum velocity when sailing to windward. The mechanics study shows the optimal C
L and C
D for a given sail and how the shape of the aerodynamic polar of the sail should be. A parametrical analysis of the aerodynamics
of a sail is then carried out varying the maximum camber, position of the maximum camber in the chord direction and position
of the maximum camber in the mast direction. The parametric analysis is done numerically with a vortex lattice method (VLM)
and experimentally in a wind tunnel. The results show that the influence of the relevant parameters studied can be reduced
to the variation of two parameters, A and B, defining the polar of the sail, C
D = B + A
2
C
L
2; and the influence of parameters A and B on the maximum VMG obtainable are calculated. 相似文献
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Pablo Coto-Millan Jose Banos-Pino Ana Rodriguez-Alvarez 《Maritime Policy and Management》2000,27(2):169-174
In this study, a stochastic frontier cost function is used to estimate the econmic efficiency of Spanish ports through panel data. The sample covers annual data of 27 Spanish ports from 1985-1989. By comparing a Cobb-Douglas function with a translog, it is found that the latter best represents the technology according to the data. Analysing the efficiency indices obtained, it is found that the relatively larger ports are more economically inefficient. Moreover, the presence of large scale economies has been detected, as well as a lack of technical progress for the period considered. 相似文献
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Transportation - This paper introduces a method for estimating the interregional transportation of certain commodities in those cases where the commodity flows are not readily available and only... 相似文献
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Abstract In recent years, concern has grown over good practices in the procurement process in public–private partnerships (PPPs). The consensus view is that PPPs are prone to higher transaction costs than traditional public provision. In this paper, we contrast the hypothesis that transaction costs in transport PPPs depend, to a large extent, on the procurement mechanism used in each case, comparing the Negotiated and the Open procedures. Given that PPPs may offer considerable benefits and significant savings over the entire life cycle of the project, it is essential for PPPs to minimize those costs that undermine efficiency gains and that deter private involvement. The quantitative analysis undertaken in this paper highlights that there is room for important savings in the tendering of PPP transport infrastructure projects, using an Open procedure. 相似文献
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Mark Richard Wilby Juan José Vinagre Díaz Ana Belén Rodríguez Gonz´lez Miguel Ángel Sotelo 《智能交通系统杂志
》2014,18(2):149-163
》2014,18(2):149-163
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. 相似文献