Bender, W.; Waytuck, D.; Wang, S.; Reed, D. A. (2018). In Situ Measurement of Wind Pressure Loadings on Pedestal Style Rooftop Photovoltaic Panels. Engineering Structures, 163, 281 – 293.
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Abstract
The installation of rooftop photovoltaic (PV) arrays is increasing throughout the US. Until recently, pedestal type PV framing systems for rooftops were basically designed using procedures from the ASCE7-10 Components and Cladding Standard for rooftop equipment. The 2011 Japanese Standard Load design guide on structures for photovoltaic arrays was useful in characterizing the pressure coefficients on rooftops, but the Standard employs different wind speed and importance factors, making its use in the US quite limited, Even the updated 2017 version is written for a different audience. Because rooftop pressure loadings are high due to flow separation, SEAOC and other organizations contracted boundary layer wind tunnel tests of panels attached to rooftops to ascertain if the ASCE7-10 equipment loadings were appropriate. The investigations resulted in new standards for pedestal-style arrays that appear in Chapter 29 of ASCE7-16. However, the new standards are limited to simple geometries and orientations, and the dynamics of the simply-supported thin PV plates do not appear to be considered. Questions regarding the ability of the boundary tunnels to simulate accurately the turbulence at the scale required for the attached panels have been raised. In response, very limited full-scale investigations in large-scale tunnels and in situ have been undertaken to calibrate the tunnel results. The results of this paper represent one of these calibration investigations. Specifically, in situ full-scale net wind pressure loadings on a rooftop PV array in a pedestal-style framing system located on the three story Hogue Technology Building of Central Washington University (CWU) in Ellensburg, Washington were measured. The CWU campus has a rural setting in a region with steady winds: Ellensburg is located in the Kittitas Breezeway portion of the Northwest wind power region. Indeed, the Wild Horse Wind and Solar Farm is located on the outskirts of town. The data described here were collected from April through August 2014. The measured net pressure coefficient time series were similar to those for rooftop pressure loadings for low-rise buildings described in the literature such as the Wind Engineering Research Field Laboratory at Texas Tech University (Ham and Bienkiewicz, 1998 [1]; Levitan and Mehta, 1992 [2]). The analysis of the net pressure time series data included an examination of the minimum, maximum, mean, and RMS values. Preliminary results suggest that the range of the values is larger than assumed in the ASCE7 Standard, and that the magnitude of the loadings vary considerably spatially over the multiple panel array. The pressure loading measurements are ongoing.
Keywords
Building Integrated Photovoltaics; Buildings (structures); Calibration; Design Engineering; Pressure Measurement; Roofs; Solar Cell Arrays; Standards; Time Series; Turbulence; Wind Tunnels; Japanese Standard Load Design Guide; Wind Pressure Loading Measurements; Asce7-10 Components-cladding Standard; Tunnel Calibration; Texas Tech University; Kittitas Breezeway Portion; Wild Horse Wind And Solar Farm; Ellensburg; Central Washington University; Hogue Technology Building; Boundary Layer Wind Tunnel Test; Flow Separation; Multiple Panel Array; Wind Engineering Research Field Laboratory; Net Pressure Coefficient Time Series; Northwest Wind Power Region; Pedestal-style Framing System; Pv Plates; Rooftop Equipment; Pedestal Style Rooftop Photovoltaic Panels; Solar-arrays; Loads; Simulation; Wind Engineering; Photovoltaic Modules; Solar Energy; Full-scale Measurements; Wind Loadings; Photovoltaic Cells; Roofing; Wind Power; Structural Engineering; Boundary Layers; Cladding; Wind Tunnel Testing; Solar Cells; In Situ Measurement; Framing; Photovoltaics; Engineering Research; Wind Measurement; Pressure; Panels; Wind Pressure; Design Standards; Fluid Dynamics; Low Rise Buildings; Colleges & Universities; Wind Speed; United States--us
Tobey, Michael B.; Binder, Robert B.; Chang, Soowon; Yoshida, Takahiro; Yamagata, Yoshiki; Yang, Perry P. J. (2019). Urban Systems Design: A Conceptual Framework for Planning Smart Communities. Smart Cities, 2(4), 522 – 537.
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Abstract
Urban systems design arises from disparate current planning approaches (urban design, Planning Support Systems, and community engagement), compounded by the reemergence of rational planning methods from new technology (Internet of Things (IoT), metric based analysis, and big data). The proposed methods join social considerations (Human Well-Being), environmental needs (Sustainability), climate change and disaster mitigation (Resilience), and prosperity (Economics) as the four foundational pillars. Urban systems design integrates planning methodologies to systematically tackle urban challenges, using IoT and rational methods, while human beings form the core of all analysis and objectives. Our approach utilizes an iterative three-phase development loop to contextualize, evaluate, plan and design scenarios for the specific needs of communities. An equal emphasis is placed on feedback loops through analysis and design, to achieve the end goal of building smart communities.
Keywords
Urban Design; Planning Support System; Resilience; Sustainability; Economics; Human Factors; Big Data
Costa, Ana; Sass, Victoria; Kennedy, Ian; Roy, Roshni; Walter, Rebecca J.; Acolin, Arthur; Crowder, Kyle; Hess, Chris; Ramiller, Alex; Chasins, Sarah. (2021). Toward a Cross-Platform Framework: Assessing the Comprehensiveness of Online Rental Listings. Cityscape, 23(2), 327 – 339.
Abstract
Research on rental housing markets in the United States has traditionally relied on national or local housing surveys. Those sources lack temporal and spatial specificity, limiting their use for tracking short-term changes in local markets. As rental housing ads have transitioned to digital spaces, a growing body of literature has utilized web scraping to analyze listing practices and variations in rental market dynamics. Those studies have primarily relied on one platform, Craigslist, as a source of data. Despite Craigslist's popularity, the authors contend that rental listings from various websites, rather than from individual ones, provide a more comprehensive picture. Using a mixed-methods approach to study listings across various platforms in five metropolitan areas, this article demonstrates considerable variation in both the types of rental units advertised and the features provided across those platforms. The article begins with an account of the birth and consolidation of online rental platforms and emergent characteristics of several selected websites, including the criteria for posting, search parameters, search results priority, and first-page search results. Visualizations are used to compare features such as the 40th percentile of rent, rent distribution, and bedroom size based on scraped data from six online platforms (Padmapper, Forrent.com , Trulia, Zillow, Craigslist, and GoSection8), 2020 Fair Market Rents, and 2019 American Community Survey data. The analyses indicate that online listing platforms target different audiences and offer distinct information on units within those market segments, resulting in markedly different estimates of local rental costs and unit size distribution depending on the platform.
Inanici, M; Abboushi, B; Safranek, S. (2022). Evaluation of Sky Spectra and Sky Models in Daylighting Simulations. Lighting Research & Technology, 1.
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Abstract
Sky models in daylight simulations represent the luminance variation across the sky-dome for different locations, dates, times and weather conditions, but skies are typically modelled as colourless. Recent studies explore techniques for incorporating the spectral content of daylighting in simulations. This paper provides an evaluation of the existing spectral sky models in lighting simulation software. The comparisons are made between the available mathematical sky models and naturally occurring skies that were recorded using high dynamic range photography and spectrophotometric measurements. The results show that recently developed sky models present progress compared to colourless sky models, but further research is needed to accurately simulate daylight spectra. [ABSTRACT FROM AUTHOR]; Copyright of Lighting Research & Technology is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Comu, Semra; Iorio, Josh; Taylor, John E.; Dossick, Carrie Sturts. (2013). Quantifying the Impact of Facilitation on Transactive Memory System Formation in Global Virtual Project Networks. Journal Of Construction Engineering & Management, 139(3), 294 – 303.
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Abstract
Building strong ties between geographically dispersed project participants is crucial to project success. In global project networks, many firms have adopted virtual collaboration tools to address the challenges imposed by temporal and geographical distance. Some researchers have examined the role of facilitators and found that process facilitation can improve collaboration. Research has also shown that facilitators can be drawn into content interactions, which may negatively impact collaboration effectiveness in virtual workspaces. Research to date has not quantified this negative impact. In this study, the formation and maintenance of transactive memory systems (TMS) in two facilitated and two nonfacilitated global virtual project networks were investigated, each executing a 2-month project. Using TMS formation and cohesive subgroup formation as a proxy for performance, quantitative evidence was found that demonstrates a negative impact on collaboration effectiveness when facilitators engage in content facilitation in virtual project networks. This paper shows that this negative impact restricts the establishment of TMSs. These findings have important implications for understanding and designing appropriate facilitator interactions in global virtual project networks. DOI: 10.1061/(ASCE)CO.1943-7862.0000610. (C) 2013 American Society of Civil Engineers.
Keywords
Globalisation; Groupware; International Collaboration; Production Engineering Computing; Project Management; Process Facilitation; Transactive Memory System Formation; Global Virtual Project Network; Virtual Collaboration Tool; Temporal Distance; Geographical Distance; Content Interaction; Virtual Workspace; Tms Cohesive Subgroup Formation; Content Facilitation; Knowledge Transfer; Group Cohesiveness; Group Cohesion; Performance; Teams; Models; Globalization; Networks; Project Networks; Social Network Analysis; Transactive Memory Systems; Virtual Teams
Feld, Shara I.; Spencer, Benjamin R.; Bolton, Susan M. (2016). Improved Fog Collection Using Turf Reinforcement Mats. Journal Of Sustainable Water In The Built Environment, 2(3).
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Abstract
Impoverished communities are particularly vulnerable to increasing water scarcity. The development of low-cost technologies that improve access to unconventional water sources, such as the freshwater contained in fog, is one way to address water scarcity. Passive fog collectors, sited to maximize exposure to orographic and advection fog, are typically constructed using 35% Raschel mesh stretched within a structural frame. To assess improvements to this technology, the fog collection potential of nonwoven turf reinforcement mats ( TRM), underwent preliminary testing in a laboratory fog tunnel and more conclusive testing at a field site in Lima, Peru. In fog tunnel tests, both of the two tested TRM specimens increased fog collection yields over 35% Raschel mesh by 26 and 33% respectively. At one field site, the tested mats increased fog collection yields over 35% Raschel mesh by 62 and 75% respectively. At a second field site, these materials increased collection volumes over the 35% Raschel mesh by 146 and 178% respectively. Differences in TRM performance at different sites were likely due to different orientation to prevailing winds at the two test stations. This work suggests that nonwoven turf reinforcement mats have the potential to improve water access in arid, foggy low income communities. (C) 2016 American Society of Civil Engineers.
Keywords
Water; Efficiency; Fresh Water; Water Resources; Water Supply; Peru; Fog Capture
Chen, Peng; Shen, Qing; Childress, Suzanne. (2018). A GPS Data-based Analysis of Built Environment Influences on Bicyclist Route Preferences. International Journal Of Sustainable Transportation, 12(3), 218 – 231.
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Abstract
This study examines the effects of built environment features, including factors of land use and road network, on bicyclists' route preferences using the data from the city of Seattle. The bicycle routes are identified using a GPS dataset collected from a smartphone application named CycleTracks. The route choice set is generated using the labeling route approach, and the cost functions of route alternatives are based on principal component analyses. Then, two mixed logit models, focusing on random parameters and alternative-specific coefficients, respectively, are estimated to examine bicyclists' route choice. The major findings of this study are as follows: (1) the bicycle route choice involves the joint consideration of convenience, safety, and leisure; (2) most bicyclists prefer to cycle on shorter, flat, and well-planned bicycle facilities with slow road traffic; (3) some bicyclists prefer routes surrounded by mixed land use; (4) some bicyclists favor routes which are planted with street trees or installed with street lights; and (5) some bicyclists prefer routes along with city features. This analysis provides valuable insights into how well-planned land use and road network can facilitate efficient, safe, and enjoyable bicycling.
Keywords
Cyclists; Mobile Apps; Multiple Correspondence Analysis (statistics); Traffic Engineering; Cycling; Bicycle Route Choice; Built Environment; Labeling Routes; Mixed Logit Model; Principal Component Analysis; Smartphone GPS Data; Choice Sets; Safe Routes; Walking; Models; Health; Infrastructure; Facilities; California; Networks
Tobey, Michael B.; Binder, Robert B.; Yoshida, Takahiro; Yamagata, Yoshiki. (2019). Urban Systems Design Case Study: Tokyo’s Sumida Ward. Smart Cities, 2(4), 453 – 470.
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Abstract
Meeting the needs of increasing environmental and systematic pressures in urban settlements requires the use of integrated and wholistic approaches. The Urban Systems Design (USD) Conceptual Framework joins the metric-based modeling of rationalized methods with human-driven goals to form a combined iterative design and analysis loop. The framework processes information for the fundamental element of cities-humans-to large-scale modeling and decision-making occurring in district- and ward-level planning. There is a need in the planning and design profession to better integrate these efforts at a greater scale to create smart communities that are inclusive and comprehensive in aspects from data management to energy and transportation networks. The purpose of this study is to examine the applicability of this method as it pertains to a model and design integrated approach. Northern Sumida Ward, located in Tokyo, exemplifies the contextualized needs of Tokyo, and Japan, while forming a coherent internal community. Focusing on methodology, our process explores the creation of typologies, metric-based analysis, and design-based approaches that are integrated into modeling. The results of the analyses provide initial evidence regarding the validity of the USD approach in modeling changes to complex systems at differing design scales, connecting various qualities of the built environment, building and urban forms, and diagnostic comparisons between baseline and change conditions. Because of some inconsistencies and the need for further evidence gathering, the methods and processes show that there is much work to be done to strengthen the model and to continue building a more productive field of USD. However, in this framework's continuing evolution, there is increasing evidence that combining the planning and design of urban systems creates a more resilient, economically viable, sustainable, and comfortable city.
Keywords
Urban Planning; Resilience; Sustainability; Economics; Human Factors; Tokyo; Planning Support System; Gis
Dunn, Peter T. (2021). Autonomous People: Identity, Agency, and Automated Driving. Journal Of Urban Technology, 28(3-4), 25 – 44.
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Abstract
The prevailing discourse on autonomous vehicles (AVs) has not yet developed a sophisticated conceptualization of autonomy and has given insufficient attention to the autonomy of people. In response, this article shifts our attention away from the AV's autonomy and towards that of its user. Autonomy is conceived here as the socially and materially situated capacity of an individual to identify and act on one's own values and desires, a capacity that is desirable for collective political life. This definition is drawn selectively from a survey of thought illustrating the richness of this concept. I then examine how studies of transportation have already made use of certain themes of autonomy in understanding mobility practices beyond dominant utilitarian models. This sets up an examination of AVs, where the existing literature tends to use a narrow conceptualization of autonomy. I then briefly examine two examples of unsettled questions in AV development, discretionary user controls and shared ride systems, in light of autonomy. The goal of this article is both to show how autonomy can be productive in understanding mobility practices, and to argue for personal autonomy as a normative value worth pursuing in the technical, political, and social development of automated mobility systems.
Keywords
Car Use; Vehicles; Travel; Accidents; Policy; Autonomy; Agency; Autonomous Vehicles; Mobility
Zhong, Bo; Wu, Shuang; Sun, Geng; Wu, Ning. (2022). Farmers’ Strategies to Climate Change and Urbanization: Potential of Ecosystem-based Adaptation in Rural Chengdu, Southwest China. International Journal Of Environmental Research And Public Health, 19(2).
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Abstract
Ecosystem-based adaptation (EbA) is emerging as a cost-effective approach for helping people adapt to climate and non-climate changes. Nowadays, climate change and urbanization have affected agricultural systems, but it is not clear how rural communities have responded or adapted to those changes. Here, we chose two typical villages in the Chengdu Plain, southwest China, through sociological surveys on 90 local farmers with a semi-structured questionnaire, participatory observation, geospatial analysis of land use and land cover, and a literature review, to explore the local people's perception of changes or disturbances and their adaptation strategies from the perspective of EbA. The results showed that climate change and urbanization had impacted agricultural systems dramatically in the last 40 years. In two case-study sites, climate change and urbanization were perceived by most local farmers as the main drivers impacting on agricultural production, but various resource-use models containing abundant traditional knowledge or practices as well as modern tools, such as information communication technology (ICT), were applied to adapt to these changes. Moreover, culture service through the adaptive decoration of rural landscapes is becoming a new perspective for implementing an EbA strategy. Finally, our findings highlighted the potential value of an EbA strategy for sustaining urban-rural integrated development and enhancing the resilience of agricultural systems.
Keywords
Ecosystem-based Adaptation (eba); Chengdu Plain; Climate Change; Urbanization; Agricultural System; Traditional Knowledge Or Practice; Functioning Ecosystem; Agro-biodiversity; Resilience; Services; Diversity; Polls & Surveys; Spatial Analysis; Topography; Rural Communities; Biodiversity; Questionnaires; Adaptation; International Organizations; Land Use; Climate Change Adaptation; Canals; Irrigation; Land Cover; Ecosystems; Case Studies; Literature Reviews; Agriculture; Farmers; Environmental Economics; Sustainable Development; Rural Areas; Gross Domestic Product--gdp; Agricultural Production; Urban Areas; Cultural Heritage; China