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31.
采用物理光学法导出金属平板RCS与倾斜角的理论公式。讨论在舰船RCS整形设计中如何采用该公式进行折衷设计和理论分析。 相似文献
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Barbara E. Baarsma Jan G. Lambooy 《Transportation Research Part D: Transport and Environment》2005,10(6):459-475
Externalities are uncompensated influences that are not expressed in a market but that affect the production possibilities or the welfare level of third parties. An example is the noise pollution in airport areas. Although air transport is an important source of economic growth and employment in many countries, the social and environmental problems connected with this sector are rising rapidly. Consequently, airports are becoming a matter of concern to many politicians. On what kind of values should they base their decisions as to further growth or consolidation of the current situation? In this paper we discuss two approaches, one based on mainstream, neo-classical, economics, and one based on institutional approaches, more in particular new institutional economics, which can be seen as a development complementary to the mainstream. 相似文献
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Louis E. Keefer 《Transportation》1985,12(4):333-342
Joint development, as the term is generally used in connection with transit systems in the United States, is real estate development that is closely linked to public transportation services and station facilities, and takes advantage of the market and locational advantages provided by them. Research conducted by LEK Associates for the Urban Mass Transportation Administration (UMTA) suggests that, in addition to helping shape urban growth and land development, joint development is also a surprisingly effective means of increasing transit system ridership and farebox revenues, as well as a source of increasingly significant revenues from the sale or lease of air rights.The completion of nine joint development projects in as many different cities, started under the former Urban Initiatives Program, for example, net additional annual ridership might reach 12000000 one-way trips. Net additional annual farebox revenues might reach over $9000000. This added revenue would be sufficient to repay the $62 million combined UMTA/transit operator investment in the nine projects, exclusive of the costs of the basic transit system improvements around which the projects are planned, in less than six years.Among transit authority-administered joint development programs examined in a separate study, the Washington Metropolitan Area Transit Authority (WMATA) has had the most success in generating significant value capture income. For example, the cumulative revenue realized by WMATA from just six joint development projects in the Washington, DC region, through September 1983 exceeded $ 6.9 million. Projections through fiscal year 1986 indicate cumulative revenues approximating $ 28 million will be received from developer leases. 相似文献
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本文对电磁悬浮型常导高速磁浮列车绝对定位传感器进行工程化设计研究。建立传感器的解析电磁学模型,并采用有限元仿真分析标志板的屏蔽特性,从而为线圈设计及传感器工作频率的选择提供依据。在此基础上,针对传感器的读码准确率、实时性和鲁棒性问题,对信号调理电路的动态特性及参数选择进行分析与设计,并基于有限状态机设计传感器的读码算法。试验表明本文所设计的传感器稳定可靠,可保证样车试验的长期顺利进行。该传感器同样适用于中低速磁浮列车,对于轮轨列车定位也有一定的参考价值。 相似文献
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结合溆浦至怀化高速公路沅水大桥深水大直径钻孔灌注桩的施工实践,介绍了岩溶地区深水环境下钻孔灌注桩的成桩工艺要点、关键施工技术及事故预防处理措施,可供类似地质条件的岩溶桩基施工借鉴。 相似文献
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宋丹 《现代城市轨道交通》2012,(6):43-45
轨道交通延伸线工程的接合处车站改造方案是影响整个工程实施的关键因素。针对长春轻轨3号线东延线过渡段2个车站信号系统的改造,详细探讨和分析信号设备变动和施工量,提出整体改造可行性方案,从工程实施难度和风险、节省投资等多个角度进行了比选。 相似文献