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921.
F. Jimnez Espadafor M. Torres García J. Becerra Villanueva J. Moreno Gutirrez 《Transportation Research Part D: Transport and Environment》2009,14(7):461-469
Heavy fuels are likely to remain the dominant fuel source for two-stroke, low-speed diesel engines for large ship propulsion for the next decade or more. There is however, potential for increased use of pure vegetable oils (PVO) as an alternative and, by emitting lower levels of several pollutants, this can help the attainment of Annex VI of the MARPOL 73/78 convention aimed at large ships using fuels with less than 4.5% sulphur or 1.5% sulphur in SOX emission control areas The use of alternative fuels can also influence the attainment of the Kyoto protocol that requires greenhouse gas emissions to be reduced by 5% by 2010 compared to 1990. This paper analyses the physical and chemical properties of various pure vegetable oils as an alternative to heavy fuel oil for large ship propulsion. 相似文献
922.
Sanghpriya H. Kamble Tom V. Mathew G.K. Sharma 《Transportation Research Part D: Transport and Environment》2009,14(2):132-140
The critical component of all emission models is a driving cycle representing the traffic behaviour. Although Indian driving cycles were developed to test the compliance of Indian vehicles to the relevant emission standards, they neglects higher speed and acceleration and assume all vehicle activities to be similar irrespective of heterogeneity in the traffic mix. Therefore, this study is an attempt to develop an urban driving cycle for estimating vehicular emissions and fuel consumption. The proposed methodology develops the driving cycle using micro-trips extracted from real-world data. The uniqueness of this methodology is that the driving cycle is constructed considering five important parameters of the time–space profile namely, the percentage acceleration, deceleration, idle, cruise, and the average speed. Therefore, this approach is expected to be a better representation of heterogeneous traffic behaviour. The driving cycle for the city of Pune in India is constructed using the proposed methodology and is compared with existing driving cycles. 相似文献
923.
Juan-Antonio Carrasco Eric J. Miller 《Transportation Research Part A: Policy and Practice》2009,43(1):90-104
This paper presents a social activity-travel generation model, which explicitly incorporates the individual’s social dimension through the concept of personal networks, modeling the multilevel structure of social relations defined by these networks. The objective of the analysis is to study the relevance of the social dimension as a source of explanation of social activity-travel generation behavior between an individual and each relevant person of their social life. The paper uses a disaggregated perspective of personal networks, explicitly incorporating the characteristics of each network member as well as the characteristics of the overall social structure. Using an ordinal multilevel specification that accounts for the social network in which individuals are embedded, four dimensions are studied: personal characteristics, “with whom” activities are performed, social network composition and structure, and ICT (information and communication technology) interaction. The results show that a proper and complete understanding of social activity generation requires going beyond the individualistic paradigm, explicitly incorporating the role of the social dimension in the study of this decision-making process. 相似文献
924.
J. Enrique Fernández L. Joaquín de Cea Ch G. Germán Valverde 《Transportation Research Part A: Policy and Practice》2009,43(5):481-499
The effect of the application of advanced transport information system (ATIS) and road pricing is studied in a transportation system under non-recurrent congestion. A stochastic network deterministic user equilibrium model (SNDUE) with elastic demand is formulated and used to evaluate the welfare and private impacts of different market penetrations of ATIS, together with road pricing for a simple network. Both marginal first-best road pricing and a second-best fixed road pricing are considered. The incentives of private users to use ATIS are analyzed and the characteristics of optimum tolls as a function of ATIS market penetration are shown. We conclude that ATIS is an efficient and necessary tool to reduce the effects of non-recurrent incidents in a transportation network, especially when non-recurrent congestion causes a significant deterioration of operational conditions of the network. If the impact of non-recurrent incidents on free flow costs is small or is reduced only to congestion effects, the use of road pricing would be more efficient. Social benefits obtained when jointly implementing ATIS and road pricing are practically the same whether first-best or second-best road pricing is used. Considering the private costs perceived by the network users, and the benefits experienced by equipped users, the maximum level of market penetration achieved could be limited because private benefits disappear after certain market penetration is obtained. 相似文献
925.
Characterizing European high speed train stations using intermodal time and entropy metrics 总被引:1,自引:0,他引:1
Francisco J. Tapiador Kerstin Burckhart Jordi Martí-Henneberg 《Transportation Research Part A: Policy and Practice》2009,43(2):197-208
This paper presents a quantitative method for characterizing high speed train stations in terms of passenger intermodality. The aim of the procedure is two-fold: firstly, the method is to be used as an objective measure for comparing stations in order to detect suboptimal points and improve the performance of stations as nodal points; secondly, the method provides a means to embed intermodality into regional accessibility models, allowing comprehensive modelling at lower scales. The empirical base of the work comprises data from 27 European high speed rail stations, which is deemed an appropriate statistical sample for the whole European rail network. Using the entropy metric, we found that several different patterns emerged: there was a clear hierarchy of stations which was linked to their respective roles within the system, while strong constraints impeded stations from performing optimally as true intermodal nodes. 相似文献
926.
Vitor R. Caldeirinha J. Augusto Felício Sandra F. da Cunha Luís Machado da Luz 《Maritime Policy and Management》2018,45(7):877-892
The diversity of port governance models in the world, sometimes even within the same country, has aroused the interest of researchers. This study is based on contingency theory to support the port governance model. The purpose is to understand the port governance model and the relation with port performance. There are three objectives: to analyze the port governance mechanisms; to analyze the port performance factors; and to understand the influence of the governance model mechanisms on port performance. A factorial analysis was used to determine the main components, and the methodology of the structural equation model was used to analyze a survey sample of 105 valid responses from specialists and managers of port user’s companies that operate in the main Portuguese ports. This study demonstrates that port governance model influences directly the port performance. The main contribution of this paper to the literature is providing a set of factors that public managers may decide when changing the characteristics of the port governance models to ensure their performance. It was also observed the approximation of the port expert vision of port governance with models described in literature. 相似文献
927.
J. Roggema 《Maritime Policy and Management》2013,40(5):265-276
This article describes an experimental project that was designed to meet the challenges of social and technological developments to the existing shipboard organization. 相似文献
928.
J. A. Zerby 《Maritime Policy and Management》2013,40(4):241-251
The potential effects of a rigid adherence to the UNCTAD Code are analysed for 26 developing countries. A brief commentary is given on the advantages of a more liberal application of the Code, including reciprocal sharing of liner tonnages by regions of developing countries with regions of developed market-economy countries. 相似文献
929.
930.
J. M. Hills D. Alcock T. Higham H. Kirkman M. Le Tissier C. Pagdilao 《Coastal management》2013,41(3):323-337
Development of awareness and capacity is a central component to the delivery of ICM and spans from local communities to national-level politicians. Education and training activities associated with ICM must be extremely varied to match both the existing capacity and role that the stakeholders play within the process of ICM. Consequently, there cannot be considered any effective “generic” ICM training; training must be tailored to match the requirements of target groups. The transfer and uptake of good-practice thus becomes an important aspect of quality enhancement in ICM capacity development. Six case studies from the Asia-Pacific region are presented that show diverse and innovative examples of good practice. A comparative analysis of these case studies is carried out in terms of institutional level of impact. In addition a generic systems-based evaluation framework is used to determine the extent to which the training impacts upon ICM implementation indicators. It is concluded that the exchange, transfer, and translation to local conditions of appropriate good practice in ICM capacity development can be an important element in enhancing the impact of ICM programs on the coastal environments and societies. Furthermore, there appears to be a positive link between the involvement of national/state/regional stakeholders in capacity-building initiatives and impacting a wider variety of indicators of ICM delivery. 相似文献