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51.
In the next few years there is likely to be a large growth of interest in the dynamic modelling of travel behaviour. In order to try to avoid the eventual collapse of enthusiasm which has sometimes occurred with other new developments when they turn out not to provide transport planning with the hoped-for panacea, this paper aims to demonstrate the diversity of approaches which will be required to tackle the subject of dynamics. In particular, it identifies three overlapping but distinct levels at which dynamics interact with travel behaviour — microdynamics, which is concerned with the detailed scheduling of activities and travel within a day — macrodynamic modifiers, whereby changes in medium- and long-term behaviour which are often considered to be instantaneous are in fact subject to important phasing considerations — and macrodynamic processes, which deal with the overriding demographic processes of birth, ageing and death. The paper suggests approaches to the incorporation of these three topics into the forecasting of travel behaviour. 相似文献
52.
Abstract Vehicle positioning is a key requirement for many safety applications. Active safety systems require precise vehicle positioning in order to assess the safety threats accurately, especially for those systems which are developed for warning/intervention in safety critical situations. When warning drivers of a local hazard (e.g. an accident site), accurate vehicle location information is important for warning the right driver groups at the right time. Global positioning system and digital maps have become major tools for vehicle positioning providing not only vehicle location information but also geometry preview of the road being used. Advances in wireless communication have made it possible for a vehicle to share its location information with other vehicles and traffic operation centres which greatly increases the opportunities to apply vehicle positioning technologies for improving road safety. This paper presents a state‐of‐the‐art review of vehicle positioning requirements for safety applications and vehicle positioning technologies. The paper also examines key issues relating to current and potential future applications of vehicle positioning technologies for improving road safety. 相似文献
53.
在未来几年之内,汽车行业将会执行更加严格的燃油经济性法规。为此,汽车设计和结构制造技术都发生了显著的变化来适应未来新法规对燃油经济性的要求。各汽车厂商2011年的新车型已悉数在美国市场亮相,而其中一些改进后将被称为2012款新车型的产品也将按计划在未来的几个月内陆续在美国汽车市场发 相似文献