The Anti-lock Braking System is an important component of the steering system in a modern car. In the latest generation of brake-by-wire systems, the performance requirements on the ABS are much higher. The controllers have to be able to maintain a specified tire slip for each wheel during braking. The authors propose a design model and based on that a gain-scheduled controller that regulates the tire-slip. Simulation and test results are presented. 相似文献
Transportation - We show how data collected from a GPS device can be incorporated in motor insurance ratemaking. The calculation of premium rates based upon driver behaviour represents an... 相似文献
This paper performs an ex-post cost–benefit and distribution analysis of the Gothenburg congestion charges introduced in 2013, based on observed effects and an ex-post evaluated transport model. Although Gothenburg is a small city with congestion limited to the highway junctions, the congestion charge scheme is socially beneficial, generating a net surplus of €20 million per year. From a financial perspective, the investment cost was repaid in slightly more than a year and, from a social surplus perspective, is repaid in < 4 years. Still, the sums that are redistributed in Gothenburg are substantially larger than the net benefit. In the distribution analysis we develop an alternative welfare rule, where the utility is translated to money by dividing the utility by the average marginal utility of money, thereby avoiding putting a higher weight on high-income people. The alternative welfare rule shows larger re-distribution effects, because paying charges is more painful for low-income classes due to the higher marginal utility of money. Low-income citizens pay a larger share of their income because all income classes are highly car dependent in Gothenburg and workers in the highest income class have considerably higher access to company cars for private trips. No correlation was found between voting pattern and gains, losses or net gain.
This paper considers railway operations in 23 European countries during 1995–2001, where a series of reform initiatives were
launched by the European Commission, and analyses whether these reform initiatives improved the efficiency of the railway
systems. Efficiency is measured using Multi-directional Efficiency Analysis, which enables investigation of how railway reforms
affect the inefficiencies of specific cost drivers. The main findings are that the reform initiatives generally improve technical
efficiency but potentially differently for different cost drivers. Specifically, the paper provides empirical evidence that
accounting separation is important for improving the efficiency in the use of both material and staff costs, whereas other
reforms only influenced one of these factors.
Dorte KronborgEmail:
Mette Asmild
is Associate Professor in Operational Research at Warwick Business School (UK). Her main research interests are theoretical
developments and practical applications of efficiency and productivity analysis techniques, particularly Data Envelopment
Analysis.
Torben Holvad
is Economic Adviser at the European Railway Agency (France), senior research associate at the Transport Studies Unit (University
of Oxford) and external associate professor at the Department of Transport (Danish Technical University). He obtained Economics
degrees from Copenhagen University (MSc) and the European University Institute in Florence (PhD).
Jens Leth Hougaard
is Professor in Applied Microeconomics at Department of Food and Resource Economics, University of Copenhagen. His main research
interests are related to applied microeconomics and include Efficiency Analysis and Benchmarking. Currently, he is working
with cost sharing methods and allocation in networks.
Dorte Kronborg
is MSc in mathematical statistics from the University of Aarhus and Associate Professor at Center for Statistics, Department
of Finance, Copenhagen Business School. Her primary research interests are applications and development of mathematical statistical
methods within business economics. 相似文献
Summary High-frequency train-track interaction and mechanisms of wheel/rail wear that is non-uniform in magnitude around/along the running surface are surveyed. Causes, consequences and suggested remedies to relieve the problems are discussed for three types of irregular wheel/rail wear: (1) short-pitch rail corrugation on tangent tracks and large radius curves, (2) wheel corrugation as caused by tread braking, and (3) wheel polygonalisation. The state-of-the-art in modelling of dynamic train-track interaction in conjunction with prediction of irregular wear is reviewed. 相似文献
This article describes a valuation method for time charter contracts for ships, i.e. leasing contracts for ships with embedded Bermudan options for buying the ship and extending the contract. As there often are embedded foreign exchange options in the buy options on the ship, a two factor stochastic model is developed and it is shown how the price can be determined applying techniques from contingent claim analysis such as dynamic programming. 相似文献
A new model system dealing with trips of length up to 100 km has recently been developed in Norway. A new way of dealing with
seasonal passes for public transport is used in the travel-to-work model. The objective was to account for the fact that a
respondent that posses a seasonal pass for public transport may behave as if public transport is free on the day they report
a travel diary. On the other hand, we can not assume that public transport is free for respondents that used other modes of
transport or that public transport is free to alternative destinations. This problem was solved by defining seasonal pass
as a separate alternative in the form of a nest that included all modes of travel. The cost of a seasonal pass is a common
cost for all modes in the nest and will thus not affect the choice within the nest. The estimation of this specification is
compared with the more common approach of assigning an average cost per day based on the cost of a monthly pass and the number
of workdays in a month. The comparison indicates that the “average cost per day” approach may produce biased estimates for
several parameters. It also turns out that the cost parameter for seasonal pass is higher than the parameter for “out of pocket”
cost, probably reflecting that there will be some uncertainty with respect to the actual use of a seasonal pass. 相似文献
Charts, Sailing Directions (SDs) and other nautical publications constitute an information unit for the mariner. All relevant
charts and publications together provide the mariner with an overview of a particular sea area. SDs are publications for voyage
planning rather than for direct navigation. These days, the Electronic Chart Display Information System (ECDIS) is on the
way to become a digital information system, which should comprise all information relevant for the mariner. Therefore, the
integration of Sailing Directions information into the present ECDIS is necessary to obtain a comprehensive ECDIS, which makes
conventional SDs and other publications superfluous. 相似文献