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981.
J. S. Dodgson 《Transportation》1994,21(4):355-370
The European aviation industry is undergoing a process of liberalisation. One of the important lessons of American deregulation was that the industry is not perfectly contestable. One implication of this is that actual competition on a route is important in order to be able to secure the benefits of deregulation or liberalisation. Another is that effective competition policy is important in order to prevent anti-competitive mergers or predatory behaviour. This paper reviews the merger investigations in European aviation which have accompanied the search by carriers to secure the benefits of market power, and considers the extent of route competition within the European Community and its relationship to the different route licensing policies of different national governments. The paper considers the extent of present competition on the busiest routes, and stresses the importance of cabotage rights in opening up the European market to effective competition. 相似文献
982.
Brian S. Hoyle 《Maritime Policy and Management》1992,19(4):279-295
This paper reports on a component of a research project on Canadian Dimensions of Waterfront Revitalization wherein forty-five interviews were held in Canadian port cities with port authority representatives, urban planners and developers. Respondents were asked to fill in a questionnaire, and the findings from this questionnaire survey are discussed in this paper. Anticipated contrasts between planning philosophies in different professions were largely but not invariably confirmed. 相似文献
983.
984.
W. H. P. Canner 《Maritime Policy and Management》1981,8(3):191-196
This paper examines the depth of air-cargo market penetration being made in the UK by the air-transport industry, following the collapse of I.A.T.A.-constructed fares a nd rates in the wake of de-regulation on the US domestic market in 1978.
It looks at statistical evidence from H.M. Customs and Excise for 1978, 1979 and 1980, and in particular makes a distribution costs analysis by comparing sea and air costs together. In the current economic climate, given today's freight rates and the fact that air-freight is rapidly turning towards bulk unitization with a frequent scheduled delivery service, a reassessment of company distribution costs could be financially beneficial to many exporters traditionally using sea transport. 相似文献
It looks at statistical evidence from H.M. Customs and Excise for 1978, 1979 and 1980, and in particular makes a distribution costs analysis by comparing sea and air costs together. In the current economic climate, given today's freight rates and the fact that air-freight is rapidly turning towards bulk unitization with a frequent scheduled delivery service, a reassessment of company distribution costs could be financially beneficial to many exporters traditionally using sea transport. 相似文献
985.
S. Erlander 《Transportation Research Part B: Methodological》1979,13(3):259-267
We consider a model which combines gravity model trip distribution and equilibrium assignment. This model contains a free parameter which must be fixed using supplementary information, that is, the model must be calibrated. It is natural to ask which supplementary information is sufficient to determine the free parameter. We show here that under very weak hypotheses each of the quantities, the entropy H or the total assignment cost F, is alone sufficient to determine the free parameter. In contrast, it is shown by means of a counterexample that even under very strong hypotheses, the total cost C is not sufficient. 相似文献
986.
Destination choice for the urban grocery shopping trip is hypothesized to be determined by three factors: the individual's perception of the destination, the individual's accessibility to the destination and the relative number of opportunities to exercise any particular choice. Results of a multinomial logit model estimation support this hypothesis and provide useful information concerning the role of urban form in this destination choice situation. It is determined that accessibility is the primary aspect influencing destination choice and that its effect is nonlinear.On leave 1977-78 from State University of New York at Buffalo, Buffalo, New York 14214. 相似文献
987.
988.
This article examines the effects of various network extraction schemes on the network design problem. Given an original network, many criteria can be used to identify subnetworks on which the network design problem is solved. For the purposes of this article, these subnetworks are obtained using an extraction algorithm which preserves the magnitude of the user equilibrium flows on the links of these subnetworks. The results of the implementation of the network design problem on the original and the extracted subnetworks are presented and compared. We conclude that very good solutions to the network design problem can be obtained from the use of highly aggregate networks. 相似文献
989.
The role of transport policy in assisting inner city firms is still unclear. This paper raises several important policy questions and reviews the findings of past research, which suggest that transport problems are a major irritant to inner city firms but are unlikely to cause them to leave the area, and that the ability of transport improvements to attract new firms is uncertain.It describes and presents the results of a recent study designed to determine the effect of transport problems on manufacturing and service industries, whether such problems are more serious in the inner city, and which solutions would be most appropriate. The study involved a series of detailed case studies of inner and outer city firms in Leeds and London. It identified as the most serious problems, congestion, public-transport problems, parking shortages and on-site delays for commercial vehicles. Similar problems arose in all areas, but were more severe in inner than in outer areas, and in London than in Leeds.The most common effect was lost time, but reduced efficiency, lost business, staff dissatisfaction and recruitment problems also occurred. Management had difficulty costing the effects of such problems, and often overlooked those incurred by others. The problems were, for the most part, local or site-specific, and are likely to be amenable to low-cost solutions. However, congestion and parking problems in inner London appear to merit area-wide treatment.A series of recommendations is provided for policy-makers.Further details of the study reported here are contained in a series of working papers which are available from the Institute for Transport Studies, University of Leeds. 相似文献
990.
D. A. Wilson R. S. Sharp S. A. Hassan 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1986,15(2):105-118
Some linear stochastic control theory relevant to the design of active suspension systems subject to integrated or filtered white noise excitation is reviewed, and application of the theory to a particular problem is considered. The problem considered is the well known quarter car problem in which a control law which minimises a performance function representing passenger discomfort, suspension working space, and tyre load fluctuations is required. With full state feedback, the requirement for a formulation of the problem which leads to the system under consideration being observable and controllable is referred to, and it is shown how a well known coordinate transformation enables this requirement to be satisfied. With limited state (or output) feedback, problem formulations which will avoid potential numerical problems in deriving the optimal control are described. Example solutions are included in order to illustrate the methods. 相似文献