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1.
This research seeks to improve the understanding of the full range of determinants for mode choice behavior and to offer practical solutions to practitioners on representing and distinguishing these characteristics in travel demand forecasting models. The principal findings were that the representation of awareness of transit services is significantly different than the underlying assumption of mode choice and forecasting models that there is perfect awareness and consideration of all modes. Furthermore, inclusion of non-traditional transit attributes and attitudes can improve mode choice models and reduce bias constants. Additional methods and analyses are necessary to bring these results into practice. The work is being conducted in two phases. This paper documents the results of Phase I, which included data collection for one case study city (Salt Lake City), research and analysis of non-traditional transit attributes in mode choice models, awareness of transit services, and recommendations for bringing these analyses into practice. Phase II will include data collection for two additional case study cities (Chicago and Charlotte) with minor modifications based on limitations identified in Phase I, additional analyses where Phase I results indicated a need, and a demonstration of the research in practice for at least one case study city.  相似文献   
2.
Thermal gradients and related deformations induced in elevated Maglev guideways by temperature variations in their environment have been predicted by a mathematical model. The deflections induced by thermal gradients in typical guideways are found to exceed specified limits for acceptable operation of an electromagnetic suspension system vehicle unless measures are taken to reduce the thermal gradients and related deflections by suitable treatment of the guideway surfaces.  相似文献   
3.
Abstract

States and other jurisdictions may protect coral reefs using biological water quality standards outlined by the United States Clean Water Act (CWA). Such protection will require long-term, regional monitoring of the resource using biological indicators and a probability-based sampling design. A 60-station survey targeting nearshore linear coral reef was conducted across southern Puerto Rico in December 2011 to document the status of reef inhabitants using a probabilistic, regional sampling design. The quantity, type and condition of stony corals, fish, gorgonians, and sponges were documented from each station, providing a robust representation of linear reef status and composition across the region. Fish represented 106 unique taxa and stony corals 32 unique taxa. Benthic organisms (stony corals, sponges, and gorgonians) averaged nearly 12 colonies per square meter, more than half of which were gorgonians. Assessment results can be used as a baseline to compare with future regional surveys to quantify change in reef condition over time (trend). Both temporal and spatial changes can be expected after large-scale disturbances like hurricanes Maria and Irma in 2017. The indicators and probabilistic sampling design support the long-term regional monitoring envisioned by the Environmental Protection Agency to implement CWA protections in Puerto Rico and elsewhere.  相似文献   
4.
The transport sector has been identified as a significant contributor to greenhouse gas emissions. As part of its emissions reduction strategy, the United Kingdom Government is demonstrating support for new vehicle technologies, paying attention, in particular, to electric vehicles.Cluster analysis was applied to Census data in order to identify potential alternative fuel vehicle drivers in the city of Birmingham, United Kingdom. The clustering was undertaken based on characteristics of age, income, car ownership, home ownership, socio-economic status and education. Almost 60% of areas that most closely fitted the profile of an alternative fuel vehicle driver were found to be located across four wards furthest from Birmingham city centre, while the areas with the poorest fit were located towards the centre of Birmingham. The paper demonstrates how Census data can be used in the initial stages of identifying potential early adopters of alternative vehicle drivers. It also shows how such research can provide scope for infrastructure planning and policy development for local and national authorities, while also providing useful marketing information to car manufacturers.  相似文献   
5.
This paper discusses structural response to blast loading and temperature changes in fires. Both extreme events can be modelled using a range of analytical techniques from simple methodologies to the very complicated finite element analysis. The relatively simple techniques are appropriate for this type of problem and degree of accuracy required given the level of uncertainty in the loading. Given specific boundary conditions and physical properties, the methodologies proposed in the paper provide as good estimates of the dynamic response to blast loading and temperature increases in fires as the more sophisticated finite element method. Experimental data compares well with the analytical results.  相似文献   
6.
为建立新的汽车酸蚀试验方法开展了一系列的研究工作,测试了酸雨的组成和pH值,统计了降雨频率和持续时间、空气和样品温度等大量的环境参数,确认pH值、温度、湿度、紫外光谱、样品的辐照量以及样品的放置角度等关键测试参数。通过对这些环境参数的记录分析,研制出一种仿酸雨溶液和一个加速测试程序,并对一款加速老化试验装置进行了改进,使其能极好地模仿户外的酸蚀结果。  相似文献   
7.
With the growing interest in the topic of attribute non-attendance, there is now widespread use of latent class (LC) structures aimed at capturing such behaviour, across a number of different fields. Specifically, these studies rely on a confirmatory LC model, using two separate values for each coefficient, one of which is fixed to zero while the other is estimated, and then use the obtained class probabilities as an indication of the degree of attribute non-attendance. In the present paper, we argue that this approach is in fact misguided, and that the results are likely to be affected by confounding with regular taste heterogeneity. We contrast the confirmatory model with an exploratory LC structure in which the values in both classes are estimated. We also put forward a combined latent class mixed logit model (LC-MMNL) which allows jointly for attribute non-attendance and for continuous taste heterogeneity. Across three separate case studies, the exploratory LC model clearly rejects the confirmatory LC approach and suggests that rates of non-attendance may be much lower than what is suggested by the standard model, or even zero. The combined LC-MMNL model similarly produces significant improvements in model fit, along with substantial reductions in the implied rate of attribute non-attendance, in some cases even eliminating the phenomena across the sample population. Our results thus call for a reappraisal of the large body of recent work that has implied high rates of attribute non-attendance for some attributes. Finally, we also highlight a number of general issues with attribute non-attendance, in particular relating to the computation of willingness to pay measures.  相似文献   
8.
There has been an assumption that because many large marine protected areas (LMPAs) are designated in areas with relatively few direct uses, they therefore have few stakeholders and negligible social outcomes. This article challenges this assumption with diverse examples of social outcomes that are distinctive in LMPAs. We define social outcomes as inclusive of both social change processes and social impacts, where “social” includes all perceptual or material human dimensions. We draw on five in-depth case studies to report social outcomes resulting from proposed or designated LMPAs in Bermuda, Rapa Nui (Easter Island), Kiribati, Palau, and the Commonwealth of the Northern Mariana Islands & Guam. We conclude: (1) social outcomes arise even in remote LMPAs; (2) LMPA efforts generate social outcomes at all stages of development; (3) LMPAs have the potential to produce outcomes at a higher level of social organization, which can change the scope and type of affected populations and, in some cases, the nature and stakes of the outcomes themselves; (4) the potential for LMPAs to impart distinctive social outcomes results from their unique geographies and/or intersection with high-level politics and policy processes; and (5) social outcomes of LMPAs may emerge in the form of social change processes and/or social impacts.  相似文献   
9.
We explore how marine ecosystem–based management (EBM) is translated from theory to practice at six sites with varying ecological and institutional contexts. Based on these case studies, we report on the goals, strategies, and outcomes of each project and what we can learn from these efforts to guide future implementation and assessment. In particular, we focus on how projects dealt with the challenges of working across geographic scales and diverse governance arrangements. While we hypothesized that EBM in the United States would be distinct from EBM in developing countries due to differences in social and political factors, we found that sites faced similar challenges. Variation among sites appeared to be more closely related to the preexisting management context and the scale at which the projects began rather than to clear differences between the United States and developing country contexts. EBM project implementers were able to overcome many of these challenges by focusing on a limited number of specific objectives, starting at a small scale, pursuing adaptive management, and monitoring a diverse set of indicators. These findings are directly relevant to current and future EBM efforts in these and other places.  相似文献   
10.
Citizen participation at the neighborhood level will become effective only if reliable procedures can be developed for involving residents in the formulation of alternative plans before official decisions are made. Therefore, a research project in transportation planning was conducted in the Pico-Union neighborhood of Los Angeles, California, in order to design and test methods for producing reliable information that could be used by the neighborhood as well as by city transportation planners.The transportation problem of most concern to the residents of Pico-Union was the patterns and uses of their local streets, rather than the usual trip-to-work problem. Two independent methods were designed for determining what street patterns and uses were most preferred by the resident: a home-interview method and a photo-comparison method. The second enabled residents to compare photographic simulations of many possible re-designs of one of their local streets, and to make individual and group decisions about them. Results of the two methods generally agreed. However, one part of the research revealed that significant differences in decisions occur when simple changes are made in the orientation and sequence of the same two photographic simulations.Methods can be developed for obtaining information useful in urban planning at the neighborhood level by involving residents in an iterative learning and decision process. Broadly representative interdisciplinary teams are needed for further research to improve the reliability of such methods and for putting them into practice.  相似文献   
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