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191.
The sequenced activity mobility simulator (SAMS): an integrated approach to modeling transportation, land use and air quality 总被引:5,自引:0,他引:5
Ryuichi Kitamura Eric I. Pas Clarisse V. Lula T. Keith Lawton Paul E. Benson 《Transportation》1996,23(3):267-291
The persistence of environmental problems in urban areas and the prospect of increasing congestion have precipitated a variety of new policies in the USA, with concomitant analytical and modeling requirements for transportation planning. This paper introduces the Sequenced Activity-Mobility Simulator (SAMS), a dynamic and integrated microsimulation forecasting system for transportation, land use and air quality, designed to overcome the deficiencies of conventional four-step travel demand forecasting systems. The proposed SAMS framework represents a departure from many of the conventional paradigms in travel demand forecasting. In particular, it aims at replicating the adaptative dynamics underlying transportation phenomena; explicitly incorporates the time-of-day dimension; represents human behavior based on the satisficing, as opposed to optimizing, principle; and endogenously forecasts socio-demographic, land use, vehicle fleet mix, and other variables that have traditionally been projected externally to be input into the forecasting process. 相似文献
192.
The methodology adopted in the design of small fishing vessels is usually concerned only with the vessel's technical characteristics and the procedures utilized may not include consideration of the relevant fishing environment. This paper describes an approach which incorporates operational, economic and technical considerations in a compressive manner. The efficiency of using multicriteria decision making methods in design is investigated with special reference to small vessels. A model is presented which takes into account various operational and fish resource factors. This allows the inclusion of a number of potentially conflicting requirements and goals within the design process. The resulting analysis identifies the optimum fleet mix for three types of fishing vessels for use in a fishing environment of a developing country. 相似文献
193.
John R. Siddorn J. Icarus Allen Jerry C. Blackford Francis J. Gilbert Jason T. Holt Martin W. Holt Jeff P. Osborne Roger Proctor David K. Mills 《Journal of Marine Systems》2007,65(1-4):417
This paper outlines an approach to complex spatio-temporal marine ecosystem modelling as applied to the North Western European Continental Shelf. The model presented here combines an eddy-permitting (approximately 6 km horizontal resolution) baroclinic model, the Proudman Oceanographic Laboratory Coastal Ocean Modelling System (POLCOMS), with the European Regional Seas Ecosystem Model (ERSEM). This has been run within an operational framework using operationally available high resolution atmospheric and lateral boundary forcing, allowing hindcast and near-real time nowcast simulations to be performed. The modelled surface temperature and chlorophyll distributions are presented, and interannual variations discussed. Validation of both the physical and ecosystem submodels show the system to be effective, whilst highlighting areas where improvements in the system can be made. Distinct regional differences in predictive skill are shown. The system presented is ready for operational implementation to provide products and services for use both scientifically and in coastal zone and shelf seas management activities. A programme of work to update the system is already in place. 相似文献
194.
T. X. Mei R. M. Goodall 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2003,39(6):415-436
Summary This paper presents the recent development on active steering for railway vehicles, and carries out a technical appraisal of different actuation schemes and control approaches. It brings together the latest research activities and findings for the full active steering techniques for rail vehicles with the solid-axle wheelsets, independently-rotating wheelsets and wheel-pairs without axles, but relevant work on passive and semi-active solutions is also briefly described. Potential benefits of the use of a combination of modern control technology and mechatronic approach are evaluated, and in particular solutions for the difficult design trade-off between the stability and the curving performance are presented. Various actuation configurations are discussed, and advantages and drawbacks of those schemes are investigated. The outline design using a number of control methods is analysed, and measurement requirement and state estimation techniques essential for implementation of the active steering schemes are also explored. In addition the issue of safety criticality is highlighted and a possible approach for developing fault-tolerant systems is proposed. Overall the paper provides an authoritative assessment of the major advances in actively-steered wheels and addresses outstanding critical issues. 相似文献
195.
The influence of workplace environment on lung function of shopkeepers working near National Highway in Jalgaon: A note 总被引:1,自引:0,他引:1
S.T. Ingle N.D. Wagh B.G. Pachpande V.S. Patel S.B. Attarde 《Transportation Research Part D: Transport and Environment》2005,10(6):476-482
The inferior ambient air quality was observed near highway passing through Jalgaon urban center. Among the pollutants critical level of particulates are observed at the roadside during May 2003 to April 2004. The shopkeepers working at the highway sides are at high risk of exposure to the air pollution caused by heavy highway traffic. The lung function test of the shopkeepers shows significant decrease in forced vital capacity, forced expiratory volume in one second and peak expiratory flow rate. The regular periodic health checkup and use of nose mask will protect the health of shopkeepers working near National Highway passing through Jalgaon urban center. 相似文献
196.
Since the mid-1990s, the effectiveness of road safety measures in Hong Kong has been weakening. Six administrations in Australia, California, Great Britain (GB), Japan, New Zealand and Sweden are selected to help review the road safety activities in Hong Kong. Nine main components of the road safety strategy, including vision, objectives, targets, action plan, evaluation and monitoring, research and development, quantitative modeling, institutional framework and funding are summarized from the road safety strategies of these overseas administrations and compared to that of Hong Kong. It is found that Hong Kong's road safety activities have to be restructured to make significant improvement. In the future, a new approach structured by the nine different road safety components is recommended. The lessons learnt can be generalized to smooth the progress of other administrations at the Intermediate Stage towards the Advanced Stage of road safety development by using the short-, medium- and long-term approaches. 相似文献
197.
T. Frede Thingstad Harry Havskum Ulla Li Zweifel Elisa Berdalet M. Montserrat Sala Francesc Peters Miquel Alcaraz Renate Scharek Maite Perez Stphan Jacquet Gro Anita Fonnes Flaten John R. Dolan Celia Marras Fereidoun Rassoulzadegan ke Hagstrm Daniel Vaulot 《Journal of Marine Systems》2007,64(1-4):15
We compared an idealised mathematical model of the lower part of the pelagic food web to experimental data from a mesocosm experiment in which the supplies of mineral nutrients (nitrogen and phosphorous), bioavailable dissolved organic carbon (BDOC, as glucose), and silicate were manipulated. The central hypothesis of the experiment was that bacterial consumption of BDOC depends on whether the growth rate of heterotrophic bacteria is limited by organic-C or by mineral nutrients. In previous work, this hypothesis was examined qualitatively using a conceptual food web model. Here we explore the extent to which a “simplest possible” mathematical version of this conceptual model can reproduce the observed dynamics. The model combines algal–bacterial competition for mineral nutrients (phosphorous) and accounts for alternative limitation of bacterial and diatom growth rates by organic carbon and by silicate, respectively. Due to a slower succession in the diatom–copepod, compared to the flagellate–ciliate link, silicate availability increases the magnitude and extends the duration of phytoplankton blooms induced by mineral nutrient addition. As a result, Si interferes negatively with bacterial consumption of BDOC consumption by increasing and prolonging algal–bacterial competition for mineral nutrients. In order to reproduce the difference in primary production between Si and non-Si amended treatments, we had to assume a carbon overflow mechanism in diatom C-fixation. This model satisfactorily reproduced central features observed in the mesocosm experiment, including the dynamics of glucose consumption, algal, bacterial, and mesozooplankton biomass. While the parameter set chosen allows the model to reproduce the pattern seen in bacterial production, we were not able to find a single set of parameters that simultaneously reproduces both the level and the pattern observed for bacterial production. Profound changes in bacterial morphology and stoichiometry were reported in glucose-amended mesocosms. Our “simplest possible” model with one bacterial population with fixed stoichiometry cannot reproduce this, and we suggest that a more elaborate representation of the bacterial community is required for more accurate reproduction of bacterial production. 相似文献
198.
E. T. Laing 《Maritime Policy and Management》1976,3(3):141-151
In Part 1*of this article a background to the economics of conference operation was provided, and conference fleet planning and single voyage costs were discussed. This part of the paper will analyse the economic objectives of conferences and will consider the implications of ending the conference princing structure. Some recommendations are also offered. 相似文献
199.
Field observations were carried out at a sea observation tower to investigate how whitecap coverage on the ocean surface responds to wave-field conditions. Images of whitecaps were taken for every 4 h or 7 h in the daytime using a 3CCD digital video camera fixed at 14 m elevation, and they were stored automatically in a hard disk video recorder at a time interval of 1 s. The determination of whitecap coverage was made by means of a digital image processing. The 1/3 power of whitecap coverage increases linearly with increasing the 10-m neutral wind speed. On the basis of the deflection angle between the propagating directions of wind waves and swell, wave-field conditions are classified into four cases. The present results show that whitecaps are produced most actively under the condition of the pure windsea and they tend to be suppressed by the presence of swell. It is difficult to find a certain relation between the deflection angle and whitecap coverage. Whitecap coverage also increases with the wave age in the same wind-speed conditions. 相似文献
200.
David T. Hartgen 《Transportation》1974,3(1):45-58
An analogy is developed between individual traveler mode choice decisions and time-dependent product adoption processes in
consumer behaviour. The structure of the adoption sequence is first described conceptually with reference to mode switch ing;
this structure is then used to develop a simple mathematical model of mode switching behaviour over time. Factors to be considered
in interpreting and operationalizing the model are then discussed at some length. The model appears too complex for direct
mathematical solution except in the simplest cases; it may however, be amenable to numerical estimation, given empirical data
on mode switching behaviour over time. 相似文献