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31.
The work described was undertaken as part of the CASSIOPE project in the EC DRIVE programme. A range of fare collection procedures in public transport is described, and the importance of these for data collection by operators is stressed. It is suggested that such data management could be standardized and to this end four case studies were carried out in different European cities. Data models were built for each city, and these models are merged into a preliminary version of a generalized model. The need and uses for such a fare collection data model is explained. 相似文献
32.
Alan W. Williams 《Transportation》1995,22(2):115-134
The paper puts the case that historical analysis helps to understand current discussions on user-pays principles and practice. In particular, (a) it is demonstrated that the nature of funding systems is dominated by political considerations, and (b) user-pays systems lead to inadequate funding of infrastructure when politically controlled, but provide funds for expansion when “market-driven” (in pursuit of profit maximisation). The case is illustrated by reference to the experience of interregional transport infrastructure in 19th century in England and 20th century Australia. Revenue deficiencies arising from government-controlled rates can lead to the demise of private transport infrastructure. The problem is considered in the context of the history of interregional roads and railways in England between the 15th and 19th century in England and in Australia in the 19th and 20th century. The current embrace by government of the user-pays system in transport services arises from fiscal deficiencies, as much from economic philosophy. User-pays policies are part of the global re-emergence of economic rationalism since the 1970s. The lesson for other nations from Australia's experience is twofold. First, in a federal system of government, despite the efficiency benefits of user-pays in interregional land transport, fiscal and political objectives will prevail. Second, in sparsely populated and/or developing countries, deregulation of long distance road transport will make funding a national highway system a critical concern. 相似文献
33.
D. R. Glen 《Maritime Policy and Management》1997,24(3):245-260
This paper examines the dynamic behaviour of second-hand prices of tankers and dry-cargo vessels over various time periods, with a view to determining whether or not the markets for such assets are efficient. It extends and re-analyses the results of an earlier study by Hale and Vanags, published in this journal in 1992. Using a more modern method of testing for cointegration, it is shown that both the tanker and dry cargo markets appear to be cointegrated, a fact which would suggest that these markets are inefficient. It is suggested that the existence of cointegration does not necessarily imply market inefficiency, if the factors that create the common trends are themselves stochastic in nature. With this in mind, it is argued that the evidence put forward in this paper is still consistent with market efficiency in the long run. 相似文献
34.
The shipping industry in Nigeria since the early 1990s has been experiencing a continuous disastrous downturn. Nigerian shipping companies' participation in international shipping has continued to be very limited. Their presence and impact is hardly felt in the world's shipping industry. Both the national carriers (that is shipping companies with national carrier status) and other indigenous private shipping companies have vessel as well as management problems. These problems have led to the poor performance of the Nigerian shipping industry for over a decade now. The carriers in the industry are not attaining for the country the gains that are supposed to emanate from shipping. This paper points out the importance of shipping to a nation, identifies the problems the country's shipping companies are facing and proffers solutions that include merging of the companies to have strong financial standing and a competitive edge. 相似文献
35.
柳长茂 《西南交通大学学报》1993,(2):74-80
本文讨论m个变元情形,得到结论:m≥2时,二阶方程为Euler-Lagrange方程的充要条件是它为Monge-Ampere方程,其系数满足某些条件。 相似文献
36.
Ship hulls are built with stiffened steel plates and experience continuous fatigue load cycles when in service. Mechanical properties of the steel are expected to change due to the application of these cyclic loads. Therefore, the mechanical properties of the material at various levels of fatigue damage need to be understood. This paper presents two test series that were conducted to determine the effect of two different strain ranges (2000 and 3000 micro strains) of fatigue cycles on the mechanical properties of high-strength structural steel. The test results indicate that the cycle-dependent behaviours of the material can cause a slight increase or a significant decrease in the yield strength when compared to its virgin state. However, the ductility of the steel does not change much as the strain cycle increases. 相似文献
37.
38.
This paper aims to gain more insight into the implications of information provision to drivers on the performance of road transport networks with recurrent congestion. For this purpose, a simulation program consisting of three components has been written. The first component is the traffic simulation model, the second component is the information provision mechanism, and the third component monitors the behavioural decision-making process of the drivers, which is modelled using a utility-based satisficing principle. Three types of information provision mechanisms will be considered: information based upon own-experience, after-trip information and real-time en route information. The findings in this paper, obtained in a hypothetical context, underline the important relationship betweenoverreaction, thelevel of market penetration and thequality of the information. High quality information allows a high level of market penetration, while low quality information, even when provided at low levels of market penetration, induces overreaction. Furthermore, real-time en route information is in particular beneficial during the process leading to a steady state; it reduces the variance in travel time considerably. The paper concludes with a discussion on the market potential of motorist information systems when commercially marketed. 相似文献
39.
J. A. Sparenberg 《Journal of Marine Science and Technology》1997,2(2):53-61
The axial force induced on a duct (duct thrust) which surrounds a propulsor is, by means of an energy conservation argument,
expressed in terms of the thrust and power of the propulsor and the kinetic energy losses per unit of time of the propulsor
and the duct. Emphasis is put on the linear theory of an axisymmetric ducted actuator disk, where it is shown that the work
done by the duct thrust is equal to the extra work done by the actuator disk when it is surrounded by the duct. This simplified
model gives more insight into the interaction between the propeller and the duct and on the limits of linearization. 相似文献
40.
Effect of capacity concentration on highway corridor performance 总被引:1,自引:0,他引:1
Randolph W. Hall 《Transportation Research Part A: Policy and Practice》1997,31(6):475-491
This paper investigates, through use of analytical models, the effects of capacity concentration on highway corridor performance. It concludes that when highways operate at a fixed total capacity, decreasing the highway spacing can increase the average travel time because highways will become more congested. When highways operate below capacity, decreasing the spacing is usually beneficial as it tends to reduce trip length when accessing highways, and allows a greater percentage of travel to be completed on highways instead of arterials. 相似文献