扬帆远航所必备的电子助航设备

2009年6月18日，8名来自大连、天津等地的帆船爱好者在大连名岛帆船俱乐部的组织下，齐聚星海湾，驾驶着LAGOON440号双体帆船，开始了大连到青岛的远洋航行。途遇八级阵风、5米海浪、电闪雷鸣；穿越了渔网密布的海域；绕过重重迷雾的成山角，经历了50多个小时的颠簸，于20日中午平安到达阳光灿烂的青岛奥帆基地。     

Dynamic threshold policy for delaying and breaking commitments in transportation auctions

In this paper we consider a transportation procurement auction consisting of shippers and carriers. Shippers offer time sensitive pickup and delivery jobs and carriers bid on these jobs. We focus on revenue maximizing strategies for the shippers in sequential auctions. For this purpose we propose two strategies, namely delaying and breaking commitments. The idea of delaying commitments is that a shipper will not agree with the best bid whenever it is above a certain reserve price. The idea of breaking commitments is that the shipper allows the carriers to break commitments against certain penalties. We evaluate the benefits of both strategies with simulation. In addition, we provide insight into the distribution of the lowest bid which is estimated by the shippers.     

汽车制动系统摩擦材料的开发

在发生紧急情况时,每个人都希望自己的车能配备如防抱死制动系统 (ABS)、牵引力控制系统,及其它保证较短制动距离的动态控制装置。同时,由于每一代的新车型比前代更大、更重、更快,对用于制动的摩擦部件的要求也越来越高。开发性能优良的摩擦材料要求供应商有丰富的专业知识与经验。     

Error and uncertainty in travel surveys

Transportation study home interview surveys normally underestimate the amount of trip-making by residents of a study area, and the data has to be adjusted subsequently to compensate for this effect. One important reason for the shortfall appears to be the incomplete recall and reporting of travel information by respondents. The paper examines the influence of the survey instrument on recall by comparing reported travel behaviour in two surveys conducted in the same town, one using a conventional travel diary and the other an activity diary. The latter format appears to encourage a more complete response, giving rise to significantly higher reported trip rates and travel times. The paper discusses some research and policy implications of this finding and concludes with tentative suggestions for improved travel survey instruments.     

New technology and maritime training in the 21<Superscript>st</Superscript> century: Implications and solutions for MET institutions

This paper examines the impact of new technology on MET institutions in the 21^st century and discusses to what extent global MET institutions can enhance and enrich traditional practices through access to new technology and the use of innovative teaching and assessment methods within a sustainable and achievable framework. It notes the diverse standards and access to new technology by MET institutions across the globe and discusses the implications for them if they are to remain competitive and viable. The paper concludes that maritime institutions can benefit from the use of new technology, but only through rational planning and sustainable staged growth. A series of continua of technical development is provided to assist institutions, from the smallest to the largest, to plan for technical development and growth in a rational and feasible way.     

Can induced traffic be measured by surveys?

This paper addresses the feasibility of measuring induced traffic by means of appropriately designed surveys. The problems which confront any attempt to measure induced traffic are described and discussed. They include: inherent variability of traffic data, difficulty in establishing what would have happened in the absence of the scheme, uncertainties in the attribution of cause and difficulty in determining the most appropriate time to conduct surveys. Some of these problems have no solution while others can be reduced with an appropriate programme of surveys and control studies. Calculations are made of the sample sizes required to achieve various levels of target accuracy. It is concluded that, given an appropriate programme of traffic counts including control studies and extensive screenlines, it should be possible at relatively modest cost and with reasonable precision, to measure the increases in traffic associated with a scheme and to identify how much of that increase is due to rerouteing. Any further disaggregation of this extra traffic into that which is due to change of mode, change of destination and increased frequency, is much more problematic. The basic traffic counts would need to be supplemented by a programme of public transport surveys, registration plate marking and/or roadside interviews, which would add very considerably to the cost of the exercise. However, even with considerable expenditure, adequate precision may be difficult to achieve and attribution of cause impossible to make.     

Evaluation and implications of environmental charges on commercial flights

Environmental charges are one of the economic instruments for controlling externalities. Their application to commercial flights has become a preferred method of encouraging the sustainable development of the air transport industry. Two kinds of externalities, aircraft noise and engine emissions, both generating profound impacts on human beings and on the environment, are considered here. The hedonic price method is applied to calculate the social cost of aircraft noise during the landing and take-off stages of the flight. The marginal impact of each flight with specific aircraft/engine combinations is derived for the allocation of aggregate noise social costs. In contrast, the dose - response method is applied to estimate the social cost of each engine exhaust pollutant during different flight modes. The combination of aircraft noise and engine emissions social costs is then evaluated on the basis of several environmental charge mechanism scenarios, using Amsterdam Airport Schiphol as a case study. It is shown that the current noise or engine emissions related charges at airports are lower than the actual social costs of their respective externalities. The implications of charge mechanism scenarios are subsequently discussed and evaluated in terms of their impacts on airline costs, airfares and passenger demand.     

Hinterland strategies of port authorities: A case study of the port of Barcelona

Port authorities generally focus on the development of the local port area and play a minor role in the development of port hinterlands, whereas shippers, forwarders, barge and rail operators have always been involved in the port-hinterland connection. The increasing importance of intermodal hinterland networks for the competitive position of ports has urged port authorities to become active in the hinterland. This new role has already been suggested by different academics. However, limited empirical evidence exists of port authorities taking stakes in inland terminals or developing transport services. Barcelona, as one of the leading port authorities in this respect, is used as a case study in this paper. The case study provides insight in the components and execution of the hinterland strategy of Barcelona. It shows that the strategy of the port authority of Barcelona and the consequent active involvement in the hinterland has had a significant impact on attracting container volumes from distant hinterlands and improving the accessibility of the port.     

Developing sustainable transport for the next generation: The need for a multi-sector approach

While some countries have made progress in encouraging more sustainable transport and travel patterns, there are limits as to how far this can be taken simply by looking at the decarbonisation of transport systems, since most travel is a derived demand and hence is strongly influenced by decisions taken by public and private sector agencies in different sectors. The paper first identifies some of the major non-transport sector influences on different aspects of travel behaviour. It then looks in more detail at changing patterns of grocery shopping over the last half century, and how these changes have been associated with new non-transport technologies and accompanying developments in business and social practices. Next, a simple visual spreadsheet tool is presented, that has been used by agencies to explore the main cross sector impacts (both positive and negative) of their major location and operating decisions. Finally, the paper proposes three ways in which cross sector synergies can be encouraged: (i) by giving each sector or major organisation responsibility for all CO₂ emissions associated with its activities, including those generated by the travel of its staff, customers, suppliers, etc.; (ii) by making major policy making within government a cross sector activity; and (iii) by developing a common, cross sector appraisal methodology for assessing the full range of impacts of policy proposals.