地理信息系统在海运智能交通中的应用

智能交通系统（ITS）是当前交通领域研究的热点,更是未来交通发展的方向。本文提出了海运智能交通系统的概念,分析了系统功能和构成。从海运交通的特点出发,以ECDIS为基础,对智能交通系统的重要组成部分－海运交通地理信息系统的处理模型、关键技术和方向进行了分析探讨。     

大攻角划船桨叶的数值模拟

采用非定常非线性涡格法对小展弦比大攻角薄翼的划船运动桨叶进行了定常、非定常运动数值模拟。通过对计算技巧的改进 ,扩展了非定常非线性涡格法的应用范围。对于极小展弦比 (λ=0 .2 )、大攻角 (α=60°)的薄翼的数值计算表明 ,所做的工作是成功的。计算了不同展弦比的平板、圆弧型桨叶的流体动力特性 ,机翼作简谐运动时的流体动力特性 ;计算了目前广泛应用的赛艇“Big Blade”桨叶的流体动力性能以及运动频率对流体动力性能的影响 ,还讨论了攻角、浸水深度等参数对桨叶流体动力性能的影响。     

Co-operation and competition in international container transport: strategies for ports

This paper focuses on the response of port authorities to the changing market environment in which they operate. It documents the changes taking place in the relationships between port authorities and terminal management companies and considers the strategic issues faced by these groups and other port interests. In particular, it investigates the potential conflicts of interest for a port authority in matters related to the level of competition amongst terminals within a port and the amount of competition amongst ports.     

Marine Stingers: Review of an Under-Recognized Global Coastal Management Issue

Dangerous marine stingers (jellyfish) are an emotive issue in tropical Australia, where they are widely regarded as the number one marine health threat. However, numerous severe and fatal stings have been reported throughout the tropical and temperate seas of the world, indicating that marine stingers are a global health problem. Further, life-threatening jellyfish stings are more frequently reported globally now compared to earlier decades, possibly as a result of improved recognition and reporting, or increased spatial and/or temporal distribution or densities. As stinging incidents may also have significant financial implications (lost tourism revenues and liability settlements), and the treatment of envenomed patients comes at high cost to the taxpayer, this issue is also a management challenge. This article outlines suggested approaches, based largely on Australian experience, for dealing with this under-recognized global coastal management issue.     

Contributions to maritime economics—Zenon S. Zannetos,the theory of oil tankship rates

This paper discusses the importance of Zannetos’ 1966 book for the development of maritime economic thought. The main contributions of the book are recounted, and the empirical work in the book is reviewed.

The analysis of the present paper is a citation research on the maritime economics literature that refers to the book. Of the 42 papers in the set, about one-third refers to the book in general. A total of 35 papers refer to one or more elements of the book, with an equal number of references to: (1) the term structure of freight rates; (2) the empirical findings on the form of the supply curve; and (3) on the verification of his results.

The general conclusion of the citation analysis is that, apparently, a number of elements of his work are still very valid for current maritime economics thinking, while maritime economists have disregarded several other elements. The latter seems unjustified for some of the business structure observations that are made in the book, such as the notion that the ship is the firm, and the elasticity of expectations. The former observation is the basis for virtually all empirical work in maritime economics that is based on individual contract data (all freight rate analysis is of this nature), and the second is the basis for the analysis of investment behaviour in shipping, investigations of cyclicality and so on.

Zannetos can definitely be seen as the initiator of the important field of term structure analysis in maritime economics. In addition to this, there are several topics in the 1966 book that are as yet unexplored, and deserve empirical scrutiny.     

Evaluating marginal improvements to a transport network: An application to the Santiago underground

This paper describes a simplified methodology designed for quick investment appraisal of improvements to a transport network, and discusses its limitations and advantages particularly in the context of a developing country. The approach basically considers:

- a method to define the total population (relevant origin-destination pairs) affected by the project

- the selection of a low-cost background model to represent transport demand on a network at an aggregate level

- the choice of a suitable marginal demand model (in this case a discrete mode choice model) capable of providing the required sensitivity and accuracy to model the project

- the estimation of the marginal demand due to the project during all the years of the study horizon, and

- a sensitivity analysis to assess the robustness of the decision recommended using these two models.

Finally, the paper summarises the results of applying the methodology to the case of an extension to the Santiago underground; it was found that the project has a high social rate of return (almost 20 per cent). However, from the point of view of a private evaluation, it can cover its operating costs only.     

Rail-road crossing impacts: an international synthesis

Rail-road crossings generate a range of transport, economic, social and environmental impacts. While much research has focused on selected impacts such as safety, little consideration has been given to wider impacts. The aim of this research was to therefore develop a holistic understanding of the impacts of rail-road crossings (both at-grade and grade-separated) and to identify key gaps in knowledge in this field. An international synthesis of rail-road crossing impacts was developed through a detailed literature review, which revealed a total of 18 different types of impacts associated with rail-road crossings. The review found that most research to date has focused on quantifying transport and economic impacts, particularly safety and road vehicle delay, with little consideration given to social and environmental impacts. A number of research gaps have been identified which provide a clear agenda for future research. These gaps include the use of empirical evidence to support impact assessments, and the need to better understand the impacts of grade-separating rail-road crossings in terms of safety, travel time variability, land use, traffic flow, rail vehicle delay, disability access, and crime.     

舰载武器体系结构的发展趋势探讨

本文根据舰载武器系统和作战指挥关系的现状和发展趋势,结合当前的装备和技术水平现状,对新型舰载武器体系结构的发展趋势进行了初步的分析和探讨。     

Development of advanced driver assistance systems with vehicle hardware-in-the-loop simulations

This paper presents a new method for the design and validation of advanced driver assistance systems (ADASs). With vehicle hardware-in-the-loop (VEHIL) simulations, the development process, and more specifically the validation phase, of intelligent vehicles is carried out safer, cheaper, and is more manageable. In the VEHIL laboratory, a full-scale ADAS-equipped vehicle is set up in a hardware-in-the-loop simulation environment, where a chassis dynamometer is used to emulate the road interaction and robot vehicles to represent other traffic. In this controlled environment, the performance and dependability of an ADAS is tested to great accuracy and reliability. The working principle and the added value of VEHIL are demonstrated with test results of an adaptive cruise control and a forward collision warning system. On the basis of the 'V' diagram, the position of VEHIL in the development process of ADASs is illustrated.     

The Added Value of Accounting For Users’ Flexibility and Information on the Potential of a Station-Based One-Way Car-Sharing System: An Application in Lisbon,Portugal

Car-sharing systems are an alternative to private transportation whereby a person may use an automobile without having to own the vehicle. The classical systems in Europe are organized in stations scattered around the city where a person may pick up a vehicle and afterward return it to the same station (round trip). Allowing a person to drop off the vehicle at any station, called one-way system, poses a significant logistics problem because it creates a significant stock imbalance at the stations, which means that there will be times when users will not have a vehicle available for their trip. Previous mathematical programming formulations have tried to overcome this limitation by optimizing trip selection and station location in a city in order to capture the best trips for balancing the system. But there was one main limitation: The users were assumed to be inflexible with respect to their choice of a station, and held to use only the one closest to their origin and destination. If the user is willing to use the second or even the third closest station the user could benefit from using real-time information on vehicle stocks at each station and be able to select the one with available capacity. In this article we extend a previous model for trip selection and station location that takes that aspect into account by considering more vehicle pick-up and drop-off station options and then apply it to a trip origin–destination matrix from the Lisbon region in Portugal. Through the extended formulation we were able to conclude that user flexibility allied with having information on vehicle stocks increases the profit of the company, as people will go directly to a station with a vehicle available, thus making the use of the fleet more efficient. Observing the size of the stations resulting from the model, we also concluded that the effect of information is enhanced by large car-sharing systems consisting of many small stations.