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51.

This paper has been written as a response to the paper of Metz (2002) on 'The limitations of transport policy'. It is argued that the issues involved are more complex than Metz implies, and that many current travel patterns stem from decisions made previously about lifestyles, as a result of changing patterns of work, the availability of home-computing facilities, and increasing aspirations and income. Neither the models nor the data sources available to transport planners reflect these trends, and transport policy tends to be simplistic. Many of the transport policy issues stem from increasing car dependency, with its implications, particularly for the elderly and for the young. It is argued that transport policy has not been very effective in the past, and it is likely to be even less so in the future. Hence, there is a need to redefine the role of the transport planner and recognize the limitations of transport policy.  相似文献   
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The use of controlled traction rods to give active yaw relaxation of coned wheelsets is investigated, and is shown to give significant improvements in curving performance without compromising stability, even on curves for which there is flange contact. An assessment of practical implications such as power, actuator and control requirements is included.  相似文献   
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This paper models traffic congestion formation on highways and roads by recognizing the centrality of dynamical systems and using concepts from complexity theory as imbedded in the spin glasses analogue. Further, it explores the concept of how an increase in air pollution caused by vehicle exhaust emission can be traced to traffic congestion, specifically to the acceleration/deceleration of vehicles on the roads. First, spin glass is introduced and then by applying the two-dimensional xy Ising model and defining a Hamiltonian (based on Edwards-Anderson and Mattis models of spin glass systems) for a system of vehicles on the road, derivations are made of the specific friction of congestion and the bulk modulus of congestion using the Gibbs-Boltzmann statistic. Similarly using the interactions of vehicles with each other and the resulting accelerations and decelerations of vehicles as the basis for exhaust emissions, derivations are made of a specificity of exhaust emissions. These are analogues to the entropy models of thermodynamics. This series of derivations serves as an analytical model for detecting incidents of congestion and increase in air pollution due to exhaust emissions in transportation systems.  相似文献   
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中国汽车生产商们首先必须了解,哪些是消费者愿意花钱购买的Telematics服务,一味地模仿西方市场,是不够的。  相似文献   
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