Obsolete Maps and Coastal Management: Case Studies from Northwest Ireland

On dynamic coastal sites, subject to rapid and sometimes unpredictable shoreline changes, management problems can be aggravated if legally authoritative maps are obsolete. These difficulties are illustrated by two case studies from County Donegal in northwest Ireland. The first case study outlines the problems that arise where statutory functional area boundaries are based on a near century-old map. The second case study deals with the problems of planning development on a site where a customized map only a few years old has been rendered obsolete by rapid coastal erosion. Other problems are caused by the inappropriate use of maps. Suggestions are made to mitigate the effects of outdated maps.     

US Navy Studies on Alternative Fuel Sources and Power and Propulsion Methods for Surface Combatants and Amphibious Warfare Ships

The US Navy has been studying the technical and cost impacts associated with the availability and cost of fossil fuel contrasted with nuclear energy alternatives for surface combatants and amphibious warfare ships. Over the past 2 years these efforts have grown in maturity to examine the tactical and strategic implications of our Navy's dependence on fossil fuels from technical, economic, and military perspectives. This paper will present three major topics:

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  Background research on alternative energy sources.
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  A survey discussion of current and future power and propulsion system technologies.
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  An overview of principal Naval Sea Systems Command studies on the integration of alternative power and propulsion system technologies into notional surface combatants, submarines, and amphibious warfare ships.

Given the US Navy's dependence on fossil fuels and the expected increase in cost and reduced availability of fossil fuel, propulsion system investment decisions made today will have a profound impact on the future tactical and strategic roles of the US Navy surface fleet. This paper lays the foundation for providing robust and flexible technology decision opportunities for the Navy's future.     

以船为家

在中国,很少人住在船上——即便真的有,也是迫于经济压力而生活在极度恶劣的食宿条件下。欧美的情况则大相径庭,人们会将或长或短地在船上居住作为一种生活方式。他们的船通常舒适而奢华。船主肯定不是穷人,但他们可能正寻求一种逃避日常生活压力的方式,抑或只是享受令人兴奋的水上生活。     

September 11 and the World Airline Financial Crisis

Abstract

This paper analyses the effectiveness of policy measures aimed at triggering a modal shift in the freight transport market. The analysis is based on the inventory‐theoretic framework that studies modal choice from a business logistics viewpoint. The crux of the inventory‐theoretic approach lies in the fact that explicit attention is paid to all costs in the supply chain that are affected by the choice of transport mode. After a brief literature review on the inventory‐theoretic framework, the framework is used to calculate the market shares of different freight transport modes for a hypothetical transport market. In a second step, the impact of some policy measures on the market shares of the transport modes is calculated. By way of illustration, the analysis is applied to the market for container transport from a seaport to its hinterland. It is shown that a combination of certain policy measures can lead to significant modal shifts from road transport to intermodal transport.     

High-Speed Generators for Power-Dense, Medium-Power, Gas Turbine Generator Sets

Concepts to improve turbine generator (TG) set power density (PD) are identified, developed, and evaluated. The evaluation focuses on the TG set as a part of overall system optimization, with weight and volume penalties for special auxiliaries. PD is given priority, while other attributes such as efficiency, acoustics, and total system cost are also assessed. The strengths and weaknesses of each concept are assessed based on technical viability, potential for PD improvement, and risk. Sixty-one generator concepts over four generator types—air-cooled wound field, water-cooled wound field, permanent magnet (PM), and high-temperature superconducting (HTS)—are evaluated with three ship-level electrical distribution architectures—high-frequency AC and active- and passive-rectified DC. A prime mover of 14 MW at 7,000 r.p.m. is assumed. The study assesses generator size enabled by directly coupling the generator to the prime mover, eliminating the typical gear required in TG sets with engine speeds greater than 3,600 r.p.m. Technology approaches are described and trends in the design data are identified. Advanced PM and superconducting rotor technologies are evaluated. For the power, speed, and system requirements studied, these technologies do not differ significantly from water-cooled designs in size and weight. A water-cooled generator would be compatible with a range of future power distribution systems such as high-frequency AC, rectified DC, or 60 Hz AC (using a rectifier and an inverter).     

Application of Models in the Design of Underwater Electromagnetic Signature Reduction Systems

The susceptibilities of surface ships and submarines to electromagnetic influence mines and detection systems are generally determined with the aid of mathematical and physical scale models of the vessel's underwater field signatures. In addition, they are the primary tools used in the design of signature reduction systems. However, limitations of model accuracy need to be recognized and identified through verification and validation, and they should not be used blindly as a substitute for critical engineering analysis. The proper use of underwater electromagnetic field models of naval vessels in designing signature reduction systems will be presented.     

如何养护你的艇

这个月我想谈谈关于游艇养护的话题。无论你拥有的是动力艇还是帆船,及时养护都能提高巡航质量并保障人员安全。在欧洲和美国,拥有一艘船通常源于强烈的爱好,很多船主愿意花费所有业余时间亲自完成养护工作,保证船上的一切清洁如新。总之,培养对船上所有系统的兴趣是个明智之举,它能使你确定所有必要工作都被正确执行。     

Estuary Management and Recreational Fishing Benefits

Recognition of the benefits to society supported by estuary ecosystem functions and services, and threats to these benefits posed by human activities, has led to various public programs to restore and protect estuaries at the federal, state, and local levels. As available budgets shrink, program administrators and public elected officials struggle to allocate limited restoration and protection funds to the highest priority areas. Economic benefit and cost information can provide useful inputs into this decision-making process by quantifying estuary restoration and protection benefits and costs in commensurate terms. In this paper, a combined actual and intended travel behavior model is described that can be applied to estimate the recreational fishing benefits of estuary restoration and protection. The model was estimated for recreational fishing in the Lower Atchafalaya River Basin estuary along the Gulf of Mexico, Louisiana, USA coast. Changes in freshwater flows into this estuary may affect redfish and speckled trout game fish populations. The model indicates that changes in catch rates of these two species would have a relatively minor affect on annual fishing trips per angler. However, because total effects may be large when effects per angler are aggregated across total anglers, resource management agencies should consider these changes in recreation benefits when evaluating projects that influence the ecology of coastal estuaries, fish populations, and catch rates. Moreover, in other coastal areas or situations, the responsiveness of angling trips to changes in catch rates may vary because of differences in user populations, environmental conditions, fish populations, and fishing experiences.     

Freighter operators' choice of airport: a three‐stage process

With increasing levels of congestion at the major cargo hubs and further restrictions on noise and night‐time flying, freighter operators' airport choice is a complex and important issue. The aim is to identify the factors that affect the airport choice of freighter operators through a review of the published literature. The literature reviewed includes work relating to passenger hub location, airport quality and airline network configuration, and other works relating to airport choice to paint a full picture of the current research in this area. The literature shows that freighter operators initially choose a shortlist of possible airports based on geography and then investigate any restrictions in place, such as capacity caps or noise limits that might block operations from that airport. Only when these hurdles have been cleared do freighter operators consider attributes of airport quality such as charges and terminal facilities, as well as other influences such as freight forwarder presence and airport marketing. Of particular prominence is the impact of legislation on airport choice.     

帆船设计与装备

如果你已经确定帆船是最佳选择,接下来就必须做出多种判断。在最开始确定何种帆船适合自己非常重要。帆船为适应这项运动的多个不同方面而设计——虽然可以购买一艘船专门用作帆船赛或是海上航行,但大多数船只的设计仍是二者的折衷,以便适应多种用途。重中之重是考虑船体形状和帆面积。