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71.
72.
Driven by concerns of climate change, governments across the world are introducing a number of policies to accelerate the uptake of low carbon vehicles (LCVs), with a specific focus on electric motors. However, there is uncertainty in the effectiveness of such policies and technology pathways, which are inherently interlinked. This article considers the short-term situation to 2020 and focuses on the concern that these policies may bring about some disproportionate impacts in society due to changes in mobility. An ethical framework is established that seeks to balance obligations to reduce greenhouse gas (GHG) emissions and rights to car ownership, then selected policies are modelled within this framework to assess acceptability of implementation. Although these policies are successful in introducing LCVs and reducing GHG emissions, findings also indicate uneven cost burdens and reduced affordability of car ownership. Following this, recommendations for policy amendments and model improvements are made. 相似文献
73.
74.
城市人行天桥美学造型简析 总被引:3,自引:0,他引:3
陈正斌 《重庆交通大学学报(自然科学版)》2007,26(4):120-123
主要阐述城市人行天桥的造型与景观的关系,城市人行天桥造型中的城市美学以及对人行天桥美学设计的认识,提出从造型与景观角度塑造城市人行天桥的观点.对城市建设有一定的应用价值. 相似文献
75.
The Powell's method was developed to determine the optimal stiffness and damping of multi-tuned mass dampers (MTMD) in offshore wind turbine (OWT) support structures under fatigue loads. Numerical examples indicated that the Powell's method results are always better than those using MTMD formulations. With the exception of the blade passing (3P) frequency, it was found in this work that a positive integer (n) multiple of the 3P frequency will also result in a large wind-induced vibration, which can be excited by the frequency of the first structural vertical rotation mode and will cause significant fatigue damage. The first translation mode TMD installed at the tower top is efficient to increase fatigue life at the tower and brace connections, but it cannot reduce fatigue damage at the column and brace connections below the platform. The second translation mode TMD can reduce fatigue damage resulting from large wave loads and thus increase the fatigue life of the braces and columns. The mode-3 TMD with a reduction in the 3(3P) vertical rotation can effectively increase the fatigue life of the braces and columns. Thus, the appropriate use of these TMDs can be effective for the fatigue problem of OWT support structures. 相似文献
76.
When a new public transport service is introduced it would be valuable for public authorities, financing organisations and
transport operators to know how long it will take for people to start to use the service and what factors influence this.
This paper presents results from research analysing the time taken for residents living close to a new guided bus service
to start to use (or adopt) the service. Data was obtained from a sample of residents on whether they used the new service
and the number of weeks after the service was introduced before they first used it. Duration modelling has been used to analyse
how the likelihood of starting to use the new service changes over time (after the introduction of the service) and to examine
what factors influence this. It is found that residents who have not used the new service are increasingly unlikely to use
it as time passes. Those residents gaining greater accessibility benefits from the new service are found to be quicker to
use the service, although the size of this effect is modest compared to that of other between-resident differences. Allowance
for the possibility that there existed a proportion of the sample that would never use the new service was tested using a
split population model (SPD) model. The SPD model indicates that 36% of residents will never use the new service and is informative
in differentiating factors that influence whether Route 20 is used and when it is used.
Kiron Chatterjee has been a Senior Lecturer at the University of the West of England, Bristol, since 2003 and previously was at the University of Southampton. Currently, a main focus of his research is on longitudinal analysis of travel behaviour to improve policy analysis. Kang-Rae Ma received a PhD in Planning from University College London. He worked at the University of the West of England, Bristol, and the Korea Transport Institute before he joined Chung-Ang University as an Assistant Professor. His research interests include modelling of travel behaviour and urban excess commuting. 相似文献
Kang-Rae MaEmail: |
Kiron Chatterjee has been a Senior Lecturer at the University of the West of England, Bristol, since 2003 and previously was at the University of Southampton. Currently, a main focus of his research is on longitudinal analysis of travel behaviour to improve policy analysis. Kang-Rae Ma received a PhD in Planning from University College London. He worked at the University of the West of England, Bristol, and the Korea Transport Institute before he joined Chung-Ang University as an Assistant Professor. His research interests include modelling of travel behaviour and urban excess commuting. 相似文献
77.
Joyce M. Dargay Stephen Clark 《Transportation Research Part A: Policy and Practice》2012,46(3):576-587
This study analyses of the determinants of long distance travel in Great Britain using data from the 1995-2006 National Travel Surveys (NTSs). The main objective is to determine the effects of socio-economic, demographic and geographic factors on long distance travel. The estimated models express the distance travelled for long distance journeys as a function of income, gender, age, employment status, household characteristics, area of residence, size of municipality, type of residence and length of time living in the area. A time trend is also included to capture common changes in long distance travel over time not included in the explanatory variables. Separate models are estimated for total travel, travel by each of four modes (car, rail, coach and air), travel by five purposes (business, commuting, leisure, holiday and visiting friends and relatives (VFRs)) and two journey lengths (<150 miles and 150+ miles one way), as well as the 35 mode-purpose-distance combinations.The results show that long distance travel is strongly related to income: air is most income-elastic, followed by rail, car and finally coach. This is the case for most journey purposes and distance bands. Notable is the substantial difference in income elasticities for rail for business/commuting as opposed to holiday/leisure/VFR. In addition, the income elasticity for coach travel is very low, and zero for the majority of purpose-distance bands, suggesting coach travel to be an inferior mode in comparison to car, rail and air. Regarding journey distance, we find that longer distance journeys are more income elastic than shorter journeys.For total long distance travel, the study indicates that women travel less than men, the elderly less than younger people, the employed and students more than others, those in one adult households more than those in larger households and those in households with children less than those without. Long distance travel is also lowest for individuals living in London and greatest for those in the South West, and increases as the size of the municipality declines. 相似文献
78.
Modelling the impact of weather conditions on active transportation travel behaviour 总被引:1,自引:0,他引:1
Sheyda Saneinejad Matthew J. RoordaChristopher Kennedy 《Transportation Research Part D: Transport and Environment》2012,17(2):129-137
Three weather sensitive models are used to explore the relationship between weather and home-based work trips within the City of Toronto, focusing on active modes of transportation. The data are restricted to non-captive commuters who have the option of selecting among five basic modes of auto driver, auto passenger, transit, bike and walk. Daily trip rates in various weather conditions are assessed. Overall, the results confirm that impact of weather on active modes of transportation is significant enough to deserve attention at the research, data collection and planning levels. 相似文献
79.
Nicholas B. Taylor 《运输规划与技术》2018,41(1):37-57
ABSTRACTPredicting the risk of traffic demands and delays exceeding critical limits at road junctions, airports, hospitals, etc., requires knowing how both mean and variance of queue size vary over time. Microscopic simulation can explore variability but is computationally demanding and gives only sample results. A computationally efficient approximation to the mean is used in many modelling tools, but only empirical extensions for variance in particular situations have been available. The paper derives theoretical formulae for time-dependent and equilibrium variance, believed to be novel and to apply generally to queues covered by the Pollaczek–Khinchin mean formula, and offering possible structural insights. These are applied in an extended approximation giving mutually consistent mean and variance estimates with improved accuracy. Tests on oversaturated peak demand cases are compared with Markov probabilistic simulation, demonstrating accuracy (R2?>?0.99) for typical random, priority-like (M/M/1) and traffic-signal-like (M/D/1) queues. Implications for risk analysis, planning and policy are considered. 相似文献
80.
Hiroshi Isshiki 《Journal of Marine Science and Technology》2001,6(2):93-109
To discuss water-wave problems in unlimited waters, it is important to know what type of wave radiation condition should
be placed on a virtual surface corresponding to infinity. For this kind of problem, the Sommerfeld radiation condition is
well known. In this article, the condition is extended to treat a case with an incident wave. Furthermore, a more general
wave radiation condition is introduced from a different point of view. The above-mentioned wave radiation conditions are introduced
into the variational principles of the Kelvin, Hellinnger–Reissner, and Dirichlet type. The Dirichlet-type variational principles
are then used in numerical calculations for bending waves in a bar, and the effectiveness of the wave radiation conditions
and the variational principles is shown. The numerical results for one-dimensional water-wave problems are then given. As
expected, the region required for the numerical solution is reduced drastically compared with that required by the Sommerfeld-type
formulation. Furthermore, the amplitude of the diverging wave is obtained in the process of reaching the variational solution.
Finally, two-dimensional water-wave problems are briefly discussed.
Received: August 9, 2001 / Accepted: September 17, 2001 相似文献