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671.
In Europe, ports are confronted with a closer integration in the maritime and shipping industries. The co-operation agreements can take several forms such as alliances and mergers among shipping lines, conferences, involvement of shipping companies in terminal management, and extending interests in inland transport of shipping companies. In this paper we give a brief overview of these different types of agreement and we examine the consequences of this evolution of the market structures in which ports and shipping companies have to operate. More specifically, attention goes to the competitive position of the port in this new environment. It is clear that the role of the port and the port authorities has to be redefined to guarantee that it remains a fully fledged player in this fast evolving integrated market. 相似文献
672.
In addition to its harmful economical and social effects, road traffic congestion is a key contributor of emissions of CO2 and local pollutants. Many traffic management policies could be implemented to tackle it. However, the impacts of those strategies on air quality and greenhouse effect are poorly predicted by classical assessment procedures. Indeed, current assessment tools are based on aggregated traffic data, which fail to capture the dynamic effects of traffic management policies on traffic flow. This article presents an estimation tool capable of measuring all the effects of traffic management policies. It is based on a commonly used dynamic traffic flow model (AIMSUN) combined with different emission models, in order to identify modelling features leading or not to differences in results. Different models combination have been applied and compared for two traffic regulation strategies: a HOV lane dedicated only to buses and taxis created on the leftmost lane of A1 between Charles de Gaulle airport and Paris, and a reduction of speed limits on a section of motorway A86 in the northwest of Paris. Substantial differences in predictions of different emission models are highlighted. They cannot be entirely explained by differences in emission laws. Other insights with regard to traffic representation and emission models?? inputs are also investigated to explain them. 相似文献
673.
Oxygen and phosphorus dynamics and cyanobacterial blooms in the Baltic Sea are discussed using results from the Swedish Coastal and Ocean Biogeochemical model (SCOBI) coupled to the Rossby Centre Ocean model (RCO). The high-resolution circulation model is used to simulate the time period from 1902 to 1998 using reconstructed physical forcing and climatological nutrient loads of the late 20th century. The analysis of the results covers the last 30 years of the simulation period. The results emphasize the importance of internal phosphorus and oxygen dynamics, the variability of physical conditions and the natural long-term variability of phosphorus supplies from land on the phosphorus content in the Baltic Sea. These mechanisms play an important role on the variability of available surface layer phosphorus in late winter in the Baltic Sea. The content of cyanobacteria increases with the availability of phosphorus in the surface layers of the Baltic proper and the probability for large cyanobacteria blooms in the model is rapidly increased at higher concentrations of excess dissolved inorganic phosphorus in late winter. The natural increase of phosphorus supplies from land due to increased river runoff since the early 1970s may to a large degree explain the increased phosphorus content in the Baltic proper. Another significant fraction of the increase is explained by the release of phosphorus from increased anoxic areas during the period. These results refer to the long-term variability of the phosphorus cycle. In accordance to earlier publications is the short-term (i.e. interannual) variability of the phosphorus content in the Baltic proper mainly explained by oxygen dependent sediment fluxes. 相似文献
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676.
The dynamic stability of a vehicle depends on various maneuvering features, such as traction, braking, and cornering. This
study presents nonlinear vehicle models for estimating the stability region and simulating the dynamic behavior of a vehicle.
Two types of vehicle models were found by considering the degrees of freedom and linearity. A simple model with nonlinear
tire dynamics is useful for determining the stability region, while a complex model (a multi-body dynamic model in MSC.ADAMS)
is appropriate for carrying out accurate simulations. Actual data for a mid-sized passenger car were used, and the models
were validated by comparison with test results. 相似文献
677.
<正>本书收录的12篇论文,系20世纪80年代初由东南亚英国学院资助召开的两次学术研讨会的研究成果,令人耳目一新。这些文章对东南亚部分重要地区从古代至19世纪末的贸易与政体之间的相互关系进行了选择性的探讨。不过,书中绝大部分的论文讨论的是1400年之后的情况,当时,贸易的迅速增长限制了该地区传统权力的变动。书中仅有一篇有关阿瑜陀耶(Ayutthaya)的文章考察了东南亚大陆的非马来地区。 相似文献
678.
寓于语境的英语词汇教学 总被引:1,自引:0,他引:1
熊娥 《武汉船舶职业技术学院学报》2010,9(2):97-99,102
针对当前大学生的英语词汇学习存在弊端这一问题,提出英语词汇教学应分为直接词汇教学和间接词汇教学,间接词汇教学应结合语境来进行。并结合话语语境、情景语境、文化语境与词汇外延意义和内涵意义的关系,分析语境对词汇教学的影响及实际意义。 相似文献
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680.
A risk analysis approach to the capital planning of vessel traffic services (VTS) is embedded within the benefit-cost methodology. The method is discussed in the Canadian context, but has already been used to plan the Hong Kong VTS system. Recently, in response to the Exxon Valdez oil spill, the US Congress asked for a study of the requirements for VTS systems in American ports and waterways, and the US Coast Guard chose to apply our risk analysis approach to their study. 相似文献