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101.
Chengfeng Wang James J. Corbett 《Transportation Research Part D: Transport and Environment》2007,12(8):577-588
Potential costs and benefits of policy options for reducing offshore ship pollution are examined using a meta-analysis of studies synthesized regionally for the US West Coast. Net benefits of reducing SO2 emissions from cargo ships in the US West Coast waters are found to range between $98 million and $284 million, annually; the benefit–cost ratio varies between 1.8 and 3.36, depending on the size of the control area and the sulfur content limit. The results show that about 21,000 tons of on-land equivalent SO2 emissions or about 33% of SO2 emissions from all mobile sources in California in 2005 can be reduced annually if the US West Coast exclusive economic zone is designated as an International Maritime Organization-compliant SOx emission control area (SECA) with fuel-sulfur content not exceeding 1.5%. The analysis demonstrates that designating this area reduces more emissions than establishing a smaller zone at a lower but favorable benefit-cost ratio. Control measures that require 0.5% low-sulfur fuels reduce more SO2 emissions, and also may have higher net benefits. Technological alternatives may achieve benefits of emissions reductions on the US West Coast across higher ranges of potential fuel prices. Combinations of fuel switching and control technology strategies provide the most cost-effective benefits from SECAs on the US West Coast and other world regions. 相似文献
102.
Taxi service at a number of major airports is supplied by one taxi company under an exclusive contract with the airport operating authority. Conventional wisdom suggests that airport taxi service produced under exclusive contract is socially inefficient. This was found to be true at the Dallas/Fort Worth Airport. In this paper we analyze the exclusive airport taxi service at Honolulu International Airport as a case study. At Honolulu International Airport, the terms of the exclusive airport taxi service contract are far less restrictive than those at Dallas/Fort Worth. Our analysis indicates that exclusive airport service can provide high quality service, reasonable prices and revenues to finance airport service. We conclude that is not the exclusivity, but rather the terms of the contract and the circumstances specific to each market that determines which system is best for a particular place. 相似文献
103.
104.
This paper investigates an issue largely ignored in the transport literature on cost overruns, namely, cost increases in the early project phase, long before the decision to build is made. This is the phase of project planning that is referred to as the front-end phase in the literature. The rationale of the study is that unless cost estimates during the front-end phase are relatively accurate, the wrong projects may be selected for further development. We first argue for why it is important to address cost escalation during the front-end phase of project planning. We then use Norwegian data to demonstrate the magnitude of cost escalations during the front-end phase of projects and in comparison to the implementation phase. We find that even in a sample of projects with relatively small cost overruns as in the case of Norway, there are substantial cost increases before the formal decision to build was made. This raises the issue of whether decisions and priorities taken at the early stages of project development are based on false information and whether this may lead to the wrong project concepts being selected. 相似文献
105.
Cheng-Chien Liu Chih-Hua Chang Ching-Gung Wen Ching-Hsiang Huang Jia-Jang Hung James T. Liu 《Journal of Marine Systems》2009,76(4):496
Mapping the water constituents from remotely sensed ocean color data enables a better understanding of the dispersal patterns of river-borne substances in the Gaoping (formerly spelled Kaoping) River, Shelf and Canyon (KPRSC) system. Based on twelve MODIS-Aqua images in the KPRSC region taken in 2005, we apply a newly developed GA-SA approach to derive maps of chlorophyll-a concentration (Chl-a), colored dissolved organic matter (CDOM) and non-algal particle/detritus/mineral (NAP). The results demonstrated that the different characteristics of Chl-a, CDOM and NAP make them ideal tracers for observing large-scale dispersal patterns. With ancillary information of averaged daily precipitation, the daily wind field obtained from QuikSCAT (Quick Scatterometer), and the 8-day composite of the temperature field obtained from MODIS-Aqua, we categorized the surface dispersal patterns as coastal, northwestward and frontal patterns. Also, for the first time, we observed a sudden increase of biomass on a large scale from a pair of ocean color images taken over only a 2-day interval. Another remarkable feature is the interaction between the southeastward flow and the intrusion of the Kuroshio Branch, resulting in complicated patterns with various scales of vortex structures and current fronts. The observed features could be used for model validation of the flow field of the KPRSC system. 相似文献
106.
Zichao Li James H. BookbinderSamir Elhedhli 《Transportation Research Part C: Emerging Technologies》2012,21(1):17-30
We study the freight forwarder’s shipment planning problem in an airfreight forwarding network where a set of cargo shipments have to be transported to given destinations. We provide mixed integer programming formulations that use piecewise-linear cargo rates and account for volume and weight constraints, flight departure/arrival times, as well as shipment-ready times.After exploring the solution of such models using CPLEX, we devise two solution methodologies to handle large problem sizes. The first is based on Lagrangian relaxation, where the problems decompose into a set of knapsack problems and a set of network flow problems. The second is a local branching heuristic that combines branching ideas and local search. The two approaches show promising results in providing good quality heuristic solutions within reasonable computational times, for difficult and large shipment consolidation problems. 相似文献
107.
Within the transport sector, modal shift towards more efficient and less polluting modes could be a key policy goal to help meet targets to reduce energy consumption and carbon emissions. However, making comparisons between modes is not necessarily straightforward. Average energy and emissions data are often relied upon, particularly for, rail, which may not be applicable to a given context. Some UK train operating companies have recently fitted electricity metres to their trains, from which energy consumption data have been obtained. This has enabled an understanding to be gained of how energy consumption and related emissions are affected by a number of factors, including train and service type. Comparisons are made with existing data for road and rail. It is noted that although more specific data can be useful in informing policy and making some decisions, average data continue to play an important role when considering the overall picture. 相似文献
108.
Transportation - This paper uses an econometric meta-regression analysis framework to examine how the mean percentage cost overruns (MPCOs) of transportation projects reported in the literature... 相似文献
109.
James K. Mitchell 《Coastal management》2013,41(3):299-327
In an otherwise complex regulatory system, the federal Environmental Impact Statement process affords local decision makers and coastal zone residents a rare opportunity to analyze the comprehensive range of land‐use and environmental issues that may arise from Offshore Continental Shelf (OCS) hydrocarbon development, while there is still time to formulate effective management strategies. As exemplified by the lease sale 40 statements, present onshore impact assessment procedures are sufficiently flawed to seriously compromise this goal. Critical deficiencies include failure to emphasize onshore impacts; insensitivity to spatial variations of impact; neglect of available data; rigid, unsupported assumptions; and preoccupation with short‐trm effects to the exclusion of more significant and dependent long‐term consequences. Suggested reforms include preparation of separate exploration and development impact statements; establishment of special Council on Environmental Quality review procedures; modification of the judicial review process; and provision of additional support to local onshore OCS impact areas. 相似文献
110.
Thomas A. Grigalunas James J. Opaluch Jerry Diamantides Marisa Mazzotta 《Coastal management》2013,41(2):61-77
Liability is an important incentive‐based instrument for preventing oil spills and provides a sustainable approach for restoring coastal resources injured by spills. However, the use of liability for environmental damages raises many challenges, including quantification of money measures of damages. In this article, case studies are used to illustrate the issues, methods, and challenges associated with assessing a range of damages, from those that can be measured relatively easily using market information to more “esoteric,”; and much more difficult, cases involving non‐market‐valued losses. Also discussed are issues raised by the new national and international regulatory focus on restoration and by the simplified, compensatory formula used by some states. 相似文献