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121.
W.W. Hall Jr. 《Coastal management》2013,41(4):247-264
Abstract This paper presents an analysis of the findings of a survey of a sample of Beaufort county, South Carolina, households which was conducted to ascertain preferences for environmental quality. These preferences were approximated from survey responses on willingness to pay for environmental amenities and the size of payments households would require to forfeit them. A scale was developed and used to rank these responses ordinally, and the matrices of scaled responses for each of eight household annual‐income classes were subjected to factor analyses. 相似文献
122.
Alan J. Horowitz 《Transportation》2010,37(4):689-703
This paper describes a group of techniques for disaggregating origin–destination tables for travel forecasting that makes
explicit use of observed traffic on a network. Five models within the group are presented, each of which uses nonlinear least-squares
estimation to obtain row and column factors for splitting trip totals from and to larger geographical areas into smaller ones.
The techniques are philosophically similar to Fratar factoring, although the solution method is quite different. The techniques
are tested on a full-sized network for Northfield, MN and are found to work effectively. 相似文献
123.
G. Menghini N. Carrasco N. Schüssler K.W. Axhausen 《Transportation Research Part A: Policy and Practice》2010,44(9):754-765
This paper presents the first route choice model for bicyclists estimated from a large sample of GPS observations and overcomes the limitations inherent in the generally employed stated preference approach. It employs an improved mode detection algorithm for GPS post-processing to determine trips made by bicycle, which are map matched to an enriched street network. The alternatives are generated as a random sample from an exhaustive, but constrained search. Accounting for the similarity between the alternatives with the path-size factor the MNL estimates show that the elasticity with regards to trip length is nearly four times larger than that with respect to the share of bike paths. The elasticity with respect to the product of length and maximum gradient of the route is small. No other variable describing the routes had an impact. The heterogeneity of the cyclists is captured through interaction terms formulated on their average behaviour. 相似文献
124.
Hybrid vehicles of different configurations and utilizing different energy storage systems have existed in development for many decades and more recently in limited production. They can be grouped as parallel, series or complex hybrids. Another classification is micro, mild and full hybrids which makes the distinction on the basis of functionality. The common energy storage systems in hybrid vehicles are batteries, supercapacitors and high speed flywheels. This paper aims to review a specific type of hybrid vehicle which involves the internal combustion engine (ICE) as the prime mover and the high speed flywheel as an energy storage device. Such hybrids are now attracting considerable interest given their potential for low cost. It is hence timely to produce a review of research and development in this subject. The flywheel is coupled to the drive line with a continuous variable transmission (CVT). The CVT can be of various types such as electrical, hydraulic or mechanical but usually in this case it is a non-electrical one. Different configurations are possible and the paper provides a timeline of the development of such powertrains with various examples. These types of hybrid vehicles have existed as prototypes for many decades and the authors believe that their development has reached levels where they can be considered serious contenders for production vehicles. 相似文献
125.
126.
V. Alkan S. M. Karamihas G. Anlas 《International Journal of Automotive Technology》2011,12(4):529-535
To investigate static tire enveloping characteristics, a three dimensional (3-D) finite element model is proposed. The vertical
stiffness of the tire is studied on a flat surface with and without cleat. Tire rubber materials and cord layers are represented
independently using “rebar” elements available in MSC Marc Mentat. Comparisons of numerical and experimental results are given
to show the validity of the proposed model. It is shown that after a certain displacement, the results of the proposed model
agree well with experimental results. In addition, the model results show that regardless of the type of the cleat placed
under the rim center (hub center), all vertical force curves intersect after a certain displacement, which indicates typical
static enveloping characteristics. Moreover, another typical characteristic of the radial tires that is unlike those of bias-ply
constructions confirms that the contact patch does not expand laterally after a level vertical load is applied to the tire,
which is directly related to fuel consumption and tire tread life. 相似文献
127.
128.
This paper explores the effect of airline emissions charges on airfares, airline service quality, aircraft design features, and network structure, using a detailed and realistic theoretical model of competing duopoly airlines. These impacts are derived by analyzing the effects of an increase in the effective price of fuel, which is the path by which emissions charges will alter airline choices. The results show that emission charges will raise fares, reduce flight frequency, increase load factors, and raise aircraft fuel efficiency, while having no effect on aircraft size. Given that these adjustments occur in response to the treatment of an emissions externality that is currently unaddressed, they represent efficient changes that move society closer to a social optimum. 相似文献
129.
The location of bus garages is a complex issue that has received recent attention in the literature. Given a bus system, the number of bus garages and their locations depend on garage cost, deadheading cost and environmental impacts. An approximate analytical model is used to determine the number of bus garages that minimizes the above costs. The concept of a slowly varying density of bus-route origins (hence deadheads) per unit area is used to model deadheading costs. The increased deadheading caused by breakdowns and accidents is also considered. The garage cost is modeled as a function of the number of buses stored. A closed-form solution is obtained for the optimal density of garages, when the garage cost function is linear. The actual locations of garages and the allocations of buses to the garages are found using a discrete space location-allocation model formulated so as to consider the environmental impact associated with buses deadheading through populated neighborhoods. 相似文献
130.
Anu Rani Sharma Shailesh Kumar Kharol K.V.S. Badarinath 《Transportation Research Part D: Transport and Environment》2010,15(3):154-159
In the present study, impact of vehicular traffic emissions on black carbon aerosol mass concentration, trace gases and ground reaching solar radiation were analyzed during nationwide truck strike of 5–12 January, 2009 over urban environment of Hyderabad, India. A significant reduction of about 57%, 60%, 40% and 50% was observed in black carbon, particulate matter, carbon monoxide and ozone respectively during nationwide truck strike period. Results of the study are important for source apportionment of pollutants as the strike created natural laboratory for studying the impact of diesel operated trucks on urban air quality. 相似文献