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This paper reviews some of the current literature concerning liner freight rates. While upholding the traditional basis for the establishment of freight rate structures it disputes some of the arguments that discrimination or differential pricing policies lead to cross-subsidization of low rated by higher rated cargoes.  相似文献   
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Abstract

During the past century, traditional ownership, control, and use of coral reef habitats in the U.S.‐affiliated islands in the Pacific have declined, exposing them to increased construction for plantation, transportation, military, urban, aquaculture, fisheries, mineral, and resort development. Dredging, filling, and other construction in coral reef and related ecosystems are expected to continue at high levels. Collectively, these activities have resulted in major adverse ecological impacts, many of which can be avoided or reduced to minor levels. Improvements in the design, siting, and construction of coastal projects can be accomplished by early integration of environmental objectives. Ecological baseline surveys; environmental impact assessments; regulatory conditions; guidelines and standards during construction; monitoring of construction; post‐construction evaluation; and long‐range research, planning, and management are among the most useful of the environmental tools to describe reefs and to identify measures to reduce or avoid adverse impacts on coral reefs.  相似文献   
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There are concerns that Cable Beach, which is of outstanding natural beauty and a major tourist attraction for Broome and the Kimberley region of northwest Australia, is suffering damage from recreational use, particularly that caused by off-road vehicles. To assess current levels of human impact on the shore and its fauna, the southern-most kilometer of the Beach, covering an area to which vehicles had access and an adjacent area closed to vehicles, was surveyed for human usage and shore crab abundance. Human usage over the recording period was high in the area with high vehicular access. The amount of litter, although considerable, was well below that recorded in some other tourist destinations elsewhere in the world. Burrows of both the ghost crabs Ocypode spp, and the sand bubbler, Scopimera inflata, were less numerous in areas of high vehicle use than those of low use. Both species may be valuable in monitoring human impacts on Cable Beach.  相似文献   
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Pantograph/Catenary Dynamics and Control   总被引:14,自引:0,他引:14  
The pantograph-catenary system with its dynamic behaviour turned out to be a crucial component for new train systems required to run at higher speeds. With the present systems, operational limitations have to be accepted when running with several pantographs in the train set, when tilting trains are employed, when running on low quality catenary sections or when stricter noise reduction regulations are forcing lower noise emissions also for the pantographs. This paper gives an overview of the methods to describe the catenary and the pantograph system dynamics. Furthermore, aspects concerning the interaction between current collectors and overhead equipment, the acquisition of the model data and the verification are presented. Finally various constructions of passive pantographs and proposals for active control concepts are discussed.  相似文献   
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