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201.
杨娥 《广州航海高等专科学校学报》2011,19(1):33-36
沥青路面性能衰减规律的预测模型是进行路面预防性养护管理的重要内容,通过采用经验法预测模型对性能指标IRI、PCI进行分析,来预测路面的使用性能,总结出经验法预测模型的建模程序和使用特点. 相似文献
202.
杨娥 《广州航海高等专科学校学报》2011,19(4):36-39
根据运用费用效益分析的原理,对沥青路面预防性养护技术进行研究;总结了预防性养护技术的费用效益分析过程和方法,对费用效益分析中的业主费用和用户费用的计算方法、用户费用组成及其影响因素进行探讨. 相似文献
203.
Dean A. JonesJulie L. Farkas Orr BernsteinChad E. Davis Adam TurkMark A. Turnquist Linda K. NozickBrian Levine Carmen G. RawlsScott D. Ostrowski William Sawaya 《Research in Transportation Economics》2011,32(1):3-14
International containerized freight movement is a vital part of the supply chain for many companies, and a critical element of moving consumer goods to points of retail sale within the U.S. Containerized imports also present a clear security concern (e.g., terrorists attempting to ship “dirty bombs,” chemical, biological or even nuclear weapons, into the U.S. in a shipping container). The goal of the research presented here is to create a modeling tool for analyzing flows of U.S. imports and exports of containerized freight, and the potential changes in those flows under a variety of conditions (e.g., port disruptions, extensive security-related delays, etc.). Our focus is on movements through maritime container ports, and not overland movements between the U.S. and Canada or Mexico.The network model, referred to as the System for Import/Export Routing and Recovery Analysis (SIERRA), represents container movements between the U.S. and 46 other countries that account for the vast majority of U.S. imports and exports. The SIERRA model is a network equilibrium model that predicts flows between foreign countries and North American ports, the total volumes handled (import and export) by each port, the modal volumes (truck and rail) moving domestically into and out of each port, and volumes between each port and a set of transportation analysis zones within the U.S. 相似文献
204.
205.
Recreation: Marine Promise, Proceedings of the National Conference on Marine Recreation Susan H. Andersen, Ed., October 2–4, 1975, Newport Beach, California Parable Beach: A Primer in Coastal Zone Economics by J. W. Devanney III, G. Ashe, and B. Parkhurst, The MIT Press, 1976, 99 pp. Marine Recreational Fisheries, Proceedings of the First Annual Marine Recreational Fisheries Symposium Henry Clepper, ed., New Orleans, Louisiana, February 27, 1976. 相似文献
206.
207.
SARA E. WALLACE 《Naval Engineers Journal》2008,120(1):23-27
Sea Perch is an underwater robotics program sponsored by the Office of Naval Research as part of the National Naval Responsibility for Naval Engineering aimed at recruiting the next generation of naval architects and marine engineers. ASNE Delaware Valley (DV) and Naval Surface Warfare Center, Philadelphia, embraced the outreach opportunity as an educational, challenging, and fun way to get kids excited about naval engineering. ASNE-DV has received an overwhelmingly positive feedback from both teachers and students. Teachers have said their students are excited to learn about remotely operated vehicles and cannot wait to work on their Sea Perch robots. During the past 3 years, ASNE-DV has teamed with Drexel University and the school district of Philadelphia to successfully implement a sustainable, local Sea Perch competition program for middle and high school students. ASNE-DV is encouraging expansion of the program to additional areas. This article discusses how the DV Sea Perch program evolved from two schools building the robots in the winter of 2005, to over 40 teams from a diverse range of schools participating in a Sea Perch competition in the spring of 2007. 相似文献
208.
Herb Castillo David E. Pitfield 《Transportation Research Part D: Transport and Environment》2010,15(4):179-188
There is significant reliance on sustainable transport indicators for monitoring and reporting progress towards sustainable transport. The selection of appropriate sustainability indicators presents a number of challenges however, not least because of the vast number of potential indicators available. To help address these challenges, this paper presents the Evaluative and Logical Approach to Sustainable Transport Indicator Compilation (ELASTIC) – a framework for identifying and selecting a small subset of sustainable transport indicators. ELASTIC is demonstrated with an application to the English Regions, UK. 相似文献
209.
Christian Hofer Martin E. Dresner Robert J. Windle 《Transportation Research Part D: Transport and Environment》2010,15(1):37-45
This study investigates how air traffic emissions taxes may impact carbon emissions in the US. The magnitude of emissions savings in the US domestic airline industry that would result from lower demand for air travel as taxes are levied and air fares increase is estimated. At the same time, the air-automobile substitution effect is considered and it is argued that some air travelers may divert to automobiles, thus increasing automobile carbon emissions. Both the analysis of the aggregate US domestic airline industry and the study of a sample of US domestic route markets indicate that potentially sizeable increases in automobile traffic and related emissions may substantially reduce the environmental benefits of air travel carbon emissions taxes. In some instances, carbon emissions may even increase in short-haul markets. Sensitivity analyses are performed to demonstrate the robustness of these findings. 相似文献
210.
The statistical characteristics of corroded steel plate surfaces exposed to marine environments are of interest for assessing longer term structural safety and integrity using probabilistic methods. This requires information about the variability of corrosion loss and pitting over surfaces. The present paper reports on the observed statistical character of the surfaces of 10 large (1.2 m × 0.8 m × 3 mm thick) steel plates exposed in temperate climate marine immersion, tidal and splash zones for 2.5 years. For the analysis the plates were cut into smaller segments that were mechanically scanned to obtain digitised surface topographies. These were then analysed to estimate the correlation structure and the standard deviation of the surface topography. Considerable differences were found for these and for the mean corrosion loss between different exposure zones. For any one segment the surface topography was found to be highly statistically dependent, implying that smaller coupon sizes can provide adequate estimates of corrosion loss. From this it may be inferred that the deepest pits are not statistically independent as commonly assumed in extreme value statistical representations. 相似文献