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231.
Onboard decision support systems (DSS) are used to increase the operational safety of ships. Ideally, DSS can estimate future ship responses within a time scale of the order of 1–3 h taking into account speed and course changes, assuming stationary sea states. In principle, the calculations depend on a large amount of operational and environmental parameters, which will be known only in the statistical sense. The present paper suggests a procedure to incorporate random variables and associated uncertainties in the calculations of the outcrossing rates that are the basis for risk-based DSS. The procedure is based on parallel system analysis, and the paper derives and describes the main ideas. The concept is illustrated by an example, where the limit state of a non-linear ship response is considered. The results from the parallel system analysis are in agreement with corresponding Monte Carlo simulations. However, the computational speed of the parallel system analysis proved slower than expected.  相似文献   
232.
Travel demand models implicitly assume that people respond to changes in a continuous way. This is in contrast to the physical sciences, where discontinuous response is a common phenomenon and is embodied in such concepts as sub-critical and supercritical states.Recent studies have shown that responses to transport policies differ in degree and kind according to the nature and severity of the stimulus and the types of people affected. Response patterns may be categorised by the extent to which they involve adjustments to spatio-temporal or inter-personal linkages. This paper identifies four response domains, with a further distinction between permissive and forced changes.Most travel demand models are designed to operate within an independent, forced (and to a less extent independent permissive) domain and their forecasts become unreliable when responses lie outside that domain. Conversely, a model designed for a more complex domain is unnecessarily cumbersome where simpler responses apply. This paper describes the types of model which are appropriate for each domain and discusses how the effects of a policy may be assigned to the correct domain(s).  相似文献   
233.
234.
This article proposes a framework for how successful shipping companies can develop strategies for growth and take advantage of business opportunities. It is essential to strengthen strategy implementation to trigger faster, internallygenerated and profitable business growth. Formal planning and control systems, as they traditionally exist in shipping companies, need to be modified to allow for such growth. The forward-thinkers, the truly dynamic companies, will be able to perceive business opportunities before anyone else, mobilize their people, and implement the necessary strategies. In doing so, a balance must be struck between the everyday and visionary focus, between the top-down and bottom-up focus, between the business and corporate portfolio focus. Shipping companies can learn from the example of the progressive business leaders in other fields, capitalizing on their way to succeed and grow, by developing a dual capability to ‘see’ new opportunities and to ‘mobilize’ the relevant organizational resources to implement these. Examples from successful shipping companies are provided.  相似文献   
235.
In this paper,numerical modeling and model testing of a complex-shaped remotely-operated vehicle(ROV) were shown.The paper emphasized the systematic modeling of hydrodynamic damping using the computational fluid dynamic software ANSYS-CFXTM on the complex-shaped ROV,a practice that is not commonly applied.For initial design and prototype testing during the developmental stage,small-scale testing using a free-decaying experiment was used to verify the theoretical models obtained from ANSYS-CFXTM.Simulation results are shown to coincide with the experimental tests.The proposed method could determine the hydrodynamic damping coefficients of the ROV.  相似文献   
236.
Abstract

This short paper supplements and updates the writer's Recent Developments in the Pricing of Local Public Transport Services, Transport Reviews, 1 (2), pp. 127–150 (1981). That paper described the situation as at 1980 in Britain, with some examples from other countries. This paper updates the position with regard to four main issues:

(a) Impact of the Transport Act 1980 in Britain, which has virtually removed fares control from stage carriage services, and removed all price and quantity control from express services by road.

(b) Further development of zonal pricing, travelcards and off‐bus fare collection on urban systems, and the effects of price reductions (and subsequent increases) in London, West Midlands, and Merseyside.

(c) Problems concerning the legality of financial support for fares policies in British cities.

(d) Following a presentation of work arising from the earlier paper at the meeting of the Transportation Research Board in Washington, D.C. in January 1983, the contrast between British and American policy is reviewed, with the writer's personal view on current policy there.

In addition, evidence on certain other points in the text is updated.  相似文献   
237.
航运经济解析   总被引:1,自引:0,他引:1  
宏观经济 在真正实现可持续增长之前,失业、外债和赤字问题依然严峻. 全球经济 世界贸易组织已经将2010年全球贸易增长率预期由今年3月的10%上调至13.5%.当前世界经济正在努力摆脱金融危机的阴霾,保持良好的增长势头.  相似文献   
238.
Although France does not have a specific law dealing with shorelines management, various policies and policy instruments exist which enable a certain amount of control over the shoreline development process. This article discusses the various institutional arrangements in France as they relate to (1) problems of marine pollution, (2) the control of land‐based pressures for shoreline use and development, and (3) the creation of a new shorelands trust. The role of existing institutions, such as the six river basin agencies, is also discussed.  相似文献   
239.
The shipping industry was transformed by the expansion of international trade and technological innovation, notably containerization, since the 1960s. Accordingly, this was followed by a significant increase in research addressing different aspects of container shipping. Despite such availability, important questions have remained unanswered: what are the major contributions that the research community has made to the container shipping industry, global and regional economies? Have their contributions been skewed towards particular themes, directions, and geographical areas? What can the shipping research community learn from the evolution and trends of container shipping research so that they can continue to contribute to the well-being of the global and regional economies? To address these questions, the paper undertakes a critical review and analysis on the evolution and trends of research in container shipping in the past four decades, based on a collection of 282 papers investigating different topics in container shipping featuring in major scholarly journals between 1967 and 2012. The study enables the shipping research community to enhance self-understandings and identifies major gaps for further research.  相似文献   
240.
This article presents an overview of trends relevant for the long-term development of Rotterdam's port complex and resulting opportunities for this complex. These trends resulted from a literature review and conversations with 20 professors in fields relevant for port development. Nine trends that can be expected to become increasingly important in the next decades are discussed. These trends include the rise of manufacturing and logistics platforms, higher land efficiency, increasingly mixed land use in port areas, and rising importance of a “regional innovation system” in ports. Opportunities and concerns for the port of Rotterdam resulting from the trends are discussed.  相似文献   
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