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141.
Amaya Alvarez-Ellacuria Alejandro Orfila Maitane Olabarrieta Luís Gómez-pujol Raúl Medina Joaquín Tintoré 《Coastal management》2013,41(6):569-584
A real-time beach hazard level associated with nearshore hydrodynamics is presented in this article. The suitability of the discussed alert system is illustrated via its application to fifteen beaches in the Balearic Islands (Western Mediterranean Sea) providing nearshore safety conditions for beach safety manager. The system provides daily forecasts of nearshore wave conditions using the deep water wave forecasts. The shallow water wave data (wave height, period, and direction) together with the morphology of the site (presence of bars, capes, beach type, etc.) are used to define a hazard level (low, medium, and high) associated with local conditions. The resulting hazard level is transmitted via SMS to lifeguards and local authorities for real-time beach management. The low computational cost of this system after the initial implementation and subsequent calibration results in a very suitable approach for beach management in order to mitigate risks related to local hydrodynamics. 相似文献
142.
Cristina Mata Israel Hervás Jesús Herranz Juan E. Malo Francisco Suárez 《Transportation Research Part D: Transport and Environment》2009,14(7):447-452
Multiple factors determine the use and effectiveness of wildlife passages and crossings installed in new roads as mitigation measures against the barrier effect. It is unknown whether factors such as seasonality determine the use of these structures. This analyses the seasonality of structure used by vertebrates. Forty-eight transverse structures crossing the A-52 motorway in north-western Spain are studied during the summer and winter of 2002–03. The use of structures by terrestrial vertebrates was monitored by tracks left in marble dust and photographic systems, and comparisons carried out by means of generalized lineal methods for count data. Structural factors mostly determined the differential use of passage types by species but seasonal changes were detected both in the intensity of use and in passage selection by some species. 相似文献
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144.
Frank 《交通世界(建养机械)》2007,(2):79
康明斯社会公益活动表现出色 在刚刚过去的2006年,康明斯社会公益活动方面再传喜讯,包括合资企业在内,康明斯在华机构总计捐赠款物超过100万人民币. 相似文献
145.
The daily activity-travel patterns of individuals often include interactions with other household members, which we observe in the form of joint activity participation and shared rides. Explicit representation of joint activity patterns is a widespread deficiency in extant travel forecasting models and remains a relatively under-developed area of travel behavior research. In this paper, we identify several spatially defined tour patterns found in weekday household survey data that describe this form of interpersonal decision-making. Using pairs of household decision makers as our subjects, we develop a structural discrete choice model that predicts the separate, parallel choices of full-day tour patterns by both persons, subject to the higher level constraint imposed by their joint selection of one of several spatial interaction patterns, one of which may be no interaction. We apply this model to the household survey data, drawing inferences from the household and person attributes that prove to be significant predictors of pattern choices, such as commitment to work schedules, auto availability, commuting distance and the presence of children in the household. Parameterization of an importance function in the models shows that in making joint activity-travel decisions significantly greater emphasis is placed on the individual utilities of workers relative to non-workers and on the utilities of women in households with very young children. The model and methods are prototypes for tour-based travel forecasting systems that seek to represent the complex interaction between household members in an integrated model structure. 相似文献
146.
Andrés Weintraub Carmen Ortiz Jaime González 《Transportation Research Part B: Methodological》1985,19(2):113-122
We consider the Frank-Wolfe algorithm in the context of the traffic assignment problem. The slow-convergence characteristics close to the optimum solution of this popular approach are well known. Several proposals have improved on the original method by modifying the search direction. We propose modifying the step size, which leads to very significant improvements in efficiency. 相似文献
147.
Modeling air carrier demand is instrumental to understanding the relative importance of competitive forces that shape the airline environment and determine a carrier's market share. This paper develops a conceptual framework for analyzing carrier demand in a competitive context and applies that framework to study air carrier choice. This framework can be used by carriers to assess the market share and revenue implications of service design, pricing, marketing, and promotional strategies. We adopt an individual traveler choice approach to identify and measure the relative importance of factors which influence air travel demand. Travelers' patterns of air travel, perceptions of carrier service, frequent-flyer program membership, and carrier choice behavior are used to estimate models of individual carrier choice. These models indicate the importance of carrier presence in the origin market, carrier service in a city pair market (share of flights), carrier quality of service reflected in ratings by individual travelers, and traveler loyalty reflected in frequent-flyer program membership on carrier choice. The importance of these variables and the specific quantitative relationship estimated, can be used to estimate the market share impact of service design, pricing, marketing, and promotional changes. The empirical results of this study demonstrate the dramatic impact of frequent-flyer program participation on carrier choice for individual flights. These effects are particularly strong among the most important air carrier market, the frequent business traveler. 相似文献
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150.
Following the growing interest in the characterisation and modelling of activity scheduling and re-scheduling behaviour, this
paper reports the results of a study on the resolution of activity scheduling conflicts. Using empirical data collected through
an Internet survey, the modification of the timing of pre-planned activities to accommodate a new activity in the schedule
was analysed. Schedule adjustment was studied using a parametric hazard model. The results indicate that the characteristics
of the activities involved are the most important factors influencing the process of schedule change. Several correlations
among schedule modifications were found.
Harry Timmermans is a Professor at the Eindhoven University of Technology. He is also Director of the Urban Planning Group and the European
Institute of Retailing and Services Studies.
Tomás Ruiz is a Lecture and researcher at the Technical University of Valencia (Spain). Prior to his employment with the University,
Dr. Ruiz was a consultant at Estudios, Proyectos y Planificación S.A. 相似文献