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261.
Madhav G. Badami Murtaza Haider 《Transportation Research Part A: Policy and Practice》2007,41(10):961-981
Maintaining and enhancing public transit service in Indian cities is important, to meet rapidly growing mass mobility needs, and curb personal motor vehicle activity and its impacts at low cost. Indian cities rely predominantly on buses for public transport, and are likely to continue to do so for years. However, the public bus transit service is inadequate, and unaffordable for the urban poor. The paper explores the factors that contribute to and affect efforts to improve this situation, based on an analysis of the financial and operational performance of the public bus transit service in the four metropolitan centres and four secondary cities during the 1990s. Overall, there were persistent losses, owing to increasing input costs and declining productivity. The losses occurred despite rapidly increasing fares, and ridership declined. The situation, and the ability to address it, is worse in the secondary cities than the metropolitan centres. We suggest a disaggregated approach based on the needs and motivations of different groups in relation to public transit, along with improved operating conditions and policies to internalize costs of personal motor vehicle use, to address the challenge of providing financially viable and affordable public bus transit service. 相似文献
262.
263.
Martin G. Richards 《Transportation》1974,3(4):335-342
This paper is intended to provide a general background to the two following papers, A Simultaneous Destination and Mode Choice Model for Shopping Trips and Some Estimation Results of a Simultaneous Model of Auto Ownership and Mode Choice to Work. Some of the deficiences of the conventional urban transport modelling system are reviewed and a case is made for the use of simultaneous models estimated with disaggregate data. 相似文献
264.
Robert G. Vambery 《Maritime Policy and Management》1974,1(3):133-135
265.
B. R. Davis A. G. Thompson 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1988,17(6):357-366
This paper considers the application of linear optimal control to the design of an active automobile suspension system. By inclusion of an integral constraint in the performance index it is possible to achieve zero steady state axle to body response to both static body forces and ramp road inputs. Full state feedback is achieved by reconstructing the state variables from easily measured quantities. 相似文献
266.
Approximate analytic methods are used to describe how the equilibrium trip time of an elevator depends upon the physical characteristics of the elevator, the passenger demand, and possible strategies of operation. The analysis is directed particularly toward elevators in buildings of moderate height (10–15 floors) at traffic levels such that the elevator is seldom idle or fully loaded. Part I describes the model and the general method for estimating means and variances of trip time if a group of floors is served by only one elevator and passenger arrivals define a homogeneous Poisson process. 相似文献
267.
G. Leister D. Bestle 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1992,21(1):129-142
For multibody systems with closed kinematic Loops a set of ordinary differential equations and decoupled algebraic equations is formulated which can be solved with explicit multistep integration algorithms. This is achieved by introducing a minimal set of generalized coordinates being specified during numerical integration. For avoiding restart of the integration algorithm after changing these variables transformation relationships are given. Velocity and acceleration constraints are satisfied exactly, position constraints are fulfilled approximately by a dynamic invariant projection onto the constraint manifold. The method is demonstrated by an application to a five-point wheel suspension. 相似文献
268.
269.
Ian G. Heggie 《Transportation》1977,6(1):19-44
British universities have entered a period of crisis. The outward manifestation of the current malady has appeared as a general cut-back in university spending. Until two or three years ago, most universities looked forward to a modest growth in activity. This has now been changed and the expectations of growth have been replaced by the reality of consolidation and modest decline. However, the universities are not alone in their dilemma. The general downturn in economic prosperity has left few institutions unscathed. Most universities, both in Britain and abroad, have therefore been forced to review their expectations and their ongoing commitments in teaching and research. The review of university activity goes much deeper than the immediate problems of finance. The current soul-searching has been sparked off by the crisis of finance, but has roots which go much deeper and touch on the very fundamentals of university education itself. In a sense, one is witnessing a belated form of public accountability: what is the purpose of a university; should its subjects be demonstrably relevant (both in themselves, as well as in their capacity to prepare students for a career); should universities engage in research and, if so, should it complement their teaching functions or be additional to it? These, and many other issues, are currently being discussed, and it is specifically with reference to their role in the field of transport research that this paper is addressed. 相似文献
270.
Robert G. Vambery 《Maritime Policy and Management》1979,6(1):25-37
The author presents a model of the conflicts that arise in the transnational shipping industry with special emphasis on control alternatives during entry into shipping operations. He concludes that, since transnational shipping is a non-zero sum game, gains can be created for world shipping as a whole. 相似文献