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AbstractThe paper presents a detailed comparative review of price/cost elasticity estimates published in a number of studies on multi-mode freight transport demands. It attempts to determine which factors could explain the wide diversity of estimates: data aggregation, diversity of markets, and methodology. It also presents new estimates for rail, road, and waterway modes, derived from a multimodal freight network model of the Rhine area market. Direct and cross-elasticities are estimated for 11 groups of commodities and per distance category. The results are critically assessed by comparison with the reviewed studies. The paper concludes with a few recommendations about meaningful uses of existing estimates and the need for additional experiments with different methodologies applied on a common data basis. 相似文献
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A redefinition of characteristic water masses in the Vietnamese upwelling area is presented based on five interdisciplinary cruises during different seasons and 331 CTD casts. In contrast to the previous definition of Rojana-anawat et al. (2001), we clearly can define water masses which serve as end members of mixing. This new definition is useful for an improved understanding of geographical positions of different water masses with respect to climate variability, the phytoplankton distribution and complex nutrient cycle in this area. 相似文献
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Amber Himes-Cornell Carlos Ormond Kristin Hoelting Natalie C. Ban J. Zachary Koehn Edward H. Allison 《Coastal management》2013,41(5):335-358
AbstractDisaster research often focuses on how and why communities are affected by a discrete extreme event. We used the community capitals framework to understand how community characteristics influence their preparedness, response to, and recovery from successive or multiple disasters using the 1964 Good Friday Earthquake and the 1989 Exxon Valdez Oil Spill as case studies. This study assesses community response to these disasters by reviewing published literature on impacts to create profiles for six communities and by identifying community capitals before and during these disasters, and throughout the long-term recovery. While the presence of rich natural capitals commonly contributed resources to pre-disaster planning and long-term recovery, restriction of resource access immediately following the disasters was detrimental to many communities. Communities with strong political, social, and financial capitals tended to fare better immediately following disasters, enabling longer-term processes of transformation or recovery. However, in some communities the oil spill undermined these capitals more than the earthquake and resulting tsunami. In understanding how use and reliance on community capitals can lead to varied recovery success from different kinds of disasters, these findings can help coastal managers and planners prepare for future disasters. 相似文献
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