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Car Parameters Identification by Handling Manoeuvres 总被引：1，自引：0，他引：1
Michele Russo Riccardo Russo Agsotino Volpe 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2000,34(6):423-436
A methodology is presented for identifying car parameters by studying the vehicle's handling. The methodology is based on the Kalman filter and makes it possible to determine the parameters on the basis of the results obtained from standard, on-road handling manoeuvres. 相似文献
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Francesco Braghin Stefano Bruni Giorgio Diana 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(4):305-325
This paper presents the results of an experimental and numerical investigation on the derailment of a railway wheelset with solid axle. Tests were carried out under quasi-steady-state conditions, on a full-scale roller rig, and allowed to point out the effect of different parameters like the wheelset's angle of attack and the ratio between the vertical loads acting on the flanging and non-flanging wheels. On the basis of the test results, some existing derailment criteria are analysed in this paper and two new criteria are proposed. A model of wheel-rail contact is proposed for the mathematical modelling of the flange climb process, and numerical vs. experimental comparisons are used to obtain model validation. 相似文献
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Francesco Frendo Giordano Greco Massimo Guiggiani 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(6):431-447
The steady-state cornering behaviour of rear-wheel drive vehicles fitted with locked differential is critically analysed by means of simple, albeit carefully formulated, vehicle models, which allow for a rigorous theoretical analysis. Results obtained for some classical manoeuvres, with either constant forward speed, steer angle or turning radius, clearly show that, in the case of locked differential, the vehicle cornering behaviour is strongly affected by the manoeuvre. As an important consequence, the handling diagram is not unique and the understeer gradient is no longer dependent only upon the lateral acceleration, as in vehicles equipped with an open differential. Accordingly, this study shows that some typical tools and concepts of vehicle dynamics are indeed inadequate in the case of locked differential. 相似文献
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Maritime shipping is a strategic sector with a strong international vocation and management. The need to define regulations valid for many different countries w... 相似文献
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Recent studies to evaluate the quality of transit service are generating a good amount of renewed interest in an old idea, the passenger's perspective; this new interest stems from recognizing that transit service quality should be characterised, measured, and managed by parameters capturing both passenger and transit operator perspectives. However, although the selected parameters are user‐oriented in their input, the output may not be as user‐oriented as considered, and the number or the percentage of passengers is often neglected. As a result, the findings are often misleading because the perspectives of transit operators dominate. Therefore, academics and practitioners must rethink their strategies of quality analysis of public transportation by stressing more on the role of passengers. These challenges are addressed in this paper with a practical, simple, and holistic framework, for Transit Quality (TRANSQUAL). This framework provides for the involvement of all stakeholders in the characterisation, measurement, and management of the stages of quality monitoring, which is jointly analyzed at different planning levels. In the characterization stage, the framework supports the selection of parameters to be monitored. The measurement stage sets and measures four quality areas in terms of percentage of passengers who expect a predefined level of service, for whom the service is designed, who receive the planned service, and who perceive the service as delivered. The management stage computes the differences between these percentages, points out criticalities, and recommends corrective actions. These stages are investigated in‐depth, integrated, and discussed in a real‐life case study. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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This paper investigates a strategic signal control, which anticipates travelers' route choice response and determines signal timings to optimize network‐wide objectives. In general traffic assignment models are used for anticipating this route choice response. However, model‐reality mismatch usually brings suboptimal solutions to the real system. A repeated anticipatory control resolves the suboptimality and addresses the modeling error by learning from information on model bias. This paper extends the repeated control approach and focuses on the estimation of flow sensitivity as well as its influence on control, which is a crucial issue in implementation of model bias correction. The main objective of this paper is first to analyze the estimation error in the real flow derivative that is estimated from noisy measurements. A dual control method is then presented, improving both optimization objective function and derivative estimation during the control process. The proposed dual algorithm is tested on a simple network as well as on a midsize network. Numerical examples confirm the reliable performance of the new reality‐tracking control strategy and its ability to identify (local) optimal solutions on real traffic networks. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Giulia Arduino David Carrillo Murillo Francesco Parola 《Maritime Policy and Management》2013,40(3):228-245
During the last 20 years, the reefer shipping sector has been characterised by a gradual changing process, leading from specialised vessels to reefer containers. In fact, the reefer bulk fleet has experienced an irreversible decline, while the reefer container fleet has shown a continuous growth. This article investigates the current major factors shaping the reefer shipping industry, in order to understand the economic drivers inducing competition between bulk and containers. Therefore, a twofold analysis has been performed. First, an overview of the reefer market, including the cold chain, the demand for refrigerated products and the supply of reefer capacity given both by containership fleet and by conventional reefer fleet. Second, a specific case of the banana trade has been carried out for evaluating the revenues of each player involved in the banana cold chain followed by a cost analysis. The results reveal the market tendencies, focusing on the main sources of competition for bulk versus container. 相似文献
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Over the last few years, liner and stevedoring markets have been facing new challenges. The progressive concentration on the demand side (carriers) and the emergence of global alliances in the mid-1990s have triggered a similar process of consolidation on the supply side (stevedores). In turn, more recently, the strategic choices of pure terminal operators have led to the progressive involvement of carriers in port operations, both from a financial and a managerial point of view. This paper aims at analysing the current contest in northern Europe between customers and suppliers of port services. Substantial concentration in the stevedoring market and the emergence of dedicated facilities in that area, make this arm-wrestling stronger and stronger. At present, the liner market is following a number of strategic directions including the pursuit of economies of scale (larger vessels) and the supply of services using faster vessels (deployment of ‘fewer’ assets) in order to offer either new services or additional loops (scope). By exploring the strategic behaviours of the top carriers (‘bigger’ or ‘more effective’), the paper attempts to outline the future evolution of the two industries in a 2015 vision, highlighting in particular scenarios for north European ports. Global alliances are weakening and a new era of M&As is probably approaching: how will the bargaining power change between port users and port customers? Which competitive paradigm will dominate? 相似文献