Kim, Jonghyeob; Lee, Hyun Woo; Bender, William; Hyun, Chang-taek. (2018). Model for Collecting Replacement Cycles of Building Components: Hybrid Approach of Indirect and Direct Estimations. Journal Of Computing In Civil Engineering, 32(6).
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Abstract
Building maintenance, repair, and replacement (MR&R) costs are estimated to be two to three times larger than initial construction costs. Thus, it is important to accurately estimate and manage MR&R costs in the planning phase and/or design phase of a construction project based on life cycle cost analysis (LCCA). However, the nature of LCCA requires making necessary assumptions for the prediction and analysis of MR&R costs, and the reliability of the assumptions greatly impacts LCCA results. In particular, determining reasonable replacement cycles is especially important given that each replacement typically involves a significant amount of capital. However, conventional approaches largely focus on either collecting component-specific replacement cases or surveying expert opinions, both of which reduce the usability and reliability of replacement cycle data at an early stage. To overcome these limitations, this study aims to develop a replacement cycle collection model that can expedite the data collection by combining indirect estimations with direct estimations. The development of the model involves collecting replacement cases, developing replacement cycle and index estimation methods, and developing an algorithm to implement the suggested model. As a validation, the applicability and effectiveness of the model were illustrated and tested by using simulated cases based on 21 real-world facilities. This study makes a theoretical contribution to the body of knowledge by developing a replacement cycle data collection model based on long-term and macro perspectives. The developed model will also be of value to practitioners when they try to improve the reliability of their LCCA.
Keywords
Buildings (structures); Life Cycle Costing; Maintenance Engineering; Structural Engineering; Building Components; Building Maintenance; Planning Phase; Design Phase; Construction Project; Life Cycle Cost Analysis; Replacement Cycle Data Collection Model; Construction Costs; Lcca; Maintenance Repair And Replacement Cost; Service Life Prediction; Repair; Replacement; Replacement Cycles; Replacement Index; Database; Indirect Estimations
Stewart, Orion T.; Moudon, Anne Vernez; Littman, Alyson J.; Seto, Edmund; Saelens, Brian E. (2018). The Association between Park Facilities and Duration of Physical Activity During Active Park Visits. Journal Of Urban Health, 95(6), 869 – 880.
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Abstract
Public parks provide places for urban residents to obtain physical activity (PA), which is associated with numerous health benefits. Adding facilities to existing parks could be a cost-effective approach to increase the duration of PA that occurs during park visits. Using objectively measured PA and comprehensively measured park visit data among an urban community-dwelling sample of adults, we tested the association between the variety of park facilities that directly support PA and the duration of PA during park visits where any PA occurred. Cross-classified multilevel models were used to account for the clustering of park visits (n=1553) within individuals (n=372) and parks (n=233). Each additional different PA facility at a park was independently associated with a 6.8% longer duration of PA bouts that included light-intensity activity, and an 8.7% longer duration of moderate to vigorous PA time. Findings from this study are consistent with the hypothesis that more PA facilities increase the amount of PA that visitors obtain while already active at a park.
Keywords
Park Facilities; Physical Activity; Park Use; Recreation; Built Environment; Global Positioning System; Accelerometer; Gis; Gps; Accelerometer Data; United-states; Adults; Proximity; Features; Walking; Size; Attractiveness; Improvements; Environment; Parks & Recreation Areas; Parks; Luminous Intensity; Clustering; Urban Areas
Bailey, David R.; Dittbrenner, Benjamin J.; Yocom, Ken P. (2019). Reintegrating The North American Beaver (castor Canadensis) In The Urban Landscape. Wires Water, 6(1).
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Abstract
In recent decades, ecological restoration and landscape architecture have focused on reintegrating ecological processes in the urban environment to support greater habitat complexity and increase biodiversity. As these values are more broadly recognized, new approaches are being investigated to increase ecosystem services and ecological benefits in urban areas. Ecosystem engineers, such as the North American beaver (Castor canadensis), can create complex habitat and influence ecological processes in natural environments. Through dam building and wetland formation, beaver can create fish habitat, diversify vegetation in riparian zones, and aggrade sediment to increase stream productivity. As beaver populations have increased in urban areas across North America, their presence presents challenges and opportunities. Beaver can be integrated into the design of new and established urban green spaces to improve ecosystem functions. If managed properly, the conflicts that beaver sometimes create can be minimized. In this paper, we examine how landscape architects and restoration ecologists are anticipating the geomorphic and hydrological implications of beaver reintroduction in the design of wetlands and urban natural areas at regional and site levels. We present an urban beaver map and three case studies in Seattle, WA, USA, to identify various approaches, successes, and management strategies for integrating the actions of beaver into project designs. We make recommendations for how designers can capitalize on the benefits of beaver by identifying sites with increased likelihood of colonization, leveraging ecosystem engineers in design conception, designing site features to reduce constraints for the reintroduction and establishment of beaver, and anticipating and managing impacts. This article is categorized under: Water and Life > Conservation, Management, and Awareness Engineering Water > Planning Water
Keywords
Beavers; Cities & Towns In Art; Nature; Riparian Areas; Municipal Water Supply; Restoration Ecology; Wetland Ecology; United States; Seattle (wash.); North America; Beaver; Biodiversity; Castor Canadensis; Ecological Design; Ecological Restoration; Ecosystem Engineers; Ecosystem Services; Species Richness; Wetland Habitat; River-basin; Dams; Channel; Streams; Impact; Water; Ponds; Ecology; Urban Populations; Habitats; Ecosystem Management; Landscape Architecture; Colonization; Fish; Geomorphology; Habitat; Design; Ecological Monitoring; Landscape; Urban Areas; Restoration; Riparian Environments; Ecosystems; Wetlands; Ecologists; Reintroduction; Case Studies; Environmental Restoration; Open Spaces; Freshwater Mammals; Urban Environments; Aquatic Mammals; Water Conservation; Ecological Effects; Disputes; Design Engineering; Dam Construction; Engineers; Urban Planning; Complexity; Hydrology
Jung, B.; Inanici, M. (2019). Measuring Circadian Lighting through High Dynamic Range Photography. Lighting Research & Technology, 51(5), 742 – 763.
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Abstract
The human ocular system functions in a dual manner. While the most well-known function is to facilitate vision, a growing body of research demonstrates its role in resetting the internal body clock to synchronize with the 24-hour daily cycle. Most research on circadian rhythms is performed in controlled laboratory environments. Little is known about the variability of circadian light within the built and natural environments. Currently, very few specialized devices measure the circadian light, and they are not accessible to many researchers and practitioners. In this paper, tristimulus colour calibration procedures for high dynamic range photography are developed to measure circadian lighting. Camera colour accuracy is evaluated through CIE trichromatic (XYZ) measurements; and the results demonstrate a strong linear relationship between the camera recordings and a scientific-grade colorimeter. Therefore, it is possible to correct for the colour aberrations and use high dynamic range photographs to measure both photopic and circadian lighting values. Spectrophotometric measurements are collected to validate the methodology. Results demonstrate that measurements from high dynamic range photographs can correspond to the physical quantity of circadian luminance with reasonable precision and repeatability. Circadian data collected in built environments can be utilized to study the impact of design decisions on human circadian entrainment and to create guidelines and metrics for designing circadian friendly environments.
Keywords
Physical Constants; Medical Photography; Photography; Built Environment; Morningness-eveningness Questionnaire; Statistical Reliability; Circadian Rhythms; Action Spectrum; Ganglion-cells; Bright Light; Exposure; Sensitivity; Framework; Daylight; Daytime; Model; Rod
Reina, Vincent; Acolin, Arthur; Bostic, Raphael W. (2019). Section 8 Vouchers and Rent Limits: Do Small Area Fair Market Rent Limits Increase Access to Opportunity Neighborhoods? An Early Evaluation. Housing Policy Debate, 29(1), 44 – 61.
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Abstract
One critique of the U.S. Department of Housing and Urban Development (HUD)'s Housing Choice Voucher program is that its maximum rent limit is set at the metropolitan level, making more expensive neighborhoods effectively off limits to households who receive rental assistance. As a result, the design of the program limits a voucher household's access to opportunity neighborhood. In response, HUD created the Small Area Fair Market Rent (SAFMR) demonstration program, which calculates the maximum voucher rent at the zip code level so that HUD's rent limits more closely align with local neighborhood rents. In theory, this program should improve a voucher household's choice set and location outcomes. Looking at changes in the location of beneficiaries in the six sites that participated in the SAFMR demonstration program, we find a significant amount of regional variation in the results. Specifically, introduction of the SAFMR rent calculations results in voucher households living in higher opportunity neighborhoods in Dallas, Texas, in lower opportunity neighborhoods in Chattanooga, Tennessee, and mixed effects in other areas. These mixed results highlight some of the potential incremental benefits of the program and reinforce the importance of viewing this policy over a longer period of time, and in the context of other constraints voucher households face in accessing neighborhood opportunity.
Keywords
Choice; Mobility; Families; Live; Section 8; Low-income Housing; Subsidized Housing; Vouchers; Neighborhood; Access; Markets; Mathematical Analysis; Federal Agencies; Urban Development; Housing; Households; Neighborhoods; Rents; Limitations; Beneficiaries; Housing Subsidies; United States--us; Dallas Texas; Chattanooga Tennessee
Zhang, Jinlei; Chen, Feng; Shen, Qing. (2019). Cluster-based LSTM Network for Short-term Passenger Flow Forecasting in Urban Rail Transit. Ieee Access, 7, 147653 – 147671.
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Abstract
Short-term passenger flow forecasting is an essential component for the operation of urban rail transit (URT). Therefore, it is necessary to obtain a higher prediction precision with the development of URT. As artificial intelligence becomes increasingly prevalent, many prediction methods including the long short-term memory network (LSTM) in the deep learning field have been applied in road transportation systems, which can give critical insights for URT. First, we propose a novel two-step K-Means clustering model to capture not only the passenger flow variation trends but also the ridership volume characteristics. Then, a predictability assessment model is developed to recommend a reasonable time granularity interval to aggregate passenger flows. Based on the clustering results and the recommended time granularity interval, the LSTM model, which is called CB-LSTM model, is proposed to conduct short-term passenger flow forecasting. Results show that the prediction based on subway station clusters can not only avoid the complication of developing numerous models for each of the hundreds of stations, but also improve the prediction performance, which make it possible to predict short-term passenger flow on a network scale using limited dataset. The results provide critical insights for subway operators and transportation policymakers.
Keywords
Traffic Flow; Neural-network; Prediction; Ridership; Models; Volume; Lstm; Short-term Passenger Flow Forecasting; Urban Rail Transit; K-means Clustering; Deep Learning
Gu, Naeun. (2020). Korean Apartment Complexes and Social Relationships of the Residents. Housing Studies, 35(8), 1362 – 1389.
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Abstract
Korean apartment housing, where more than half of the population lives, has drawn attention with its spatial, historical, and cultural uniqueness. Among many questions on Korean apartments, this article explains how the socio-spatial characteristics of apartment housing have impacts on the social relationships among the residents. This article first analyses the historical, socio-cultural, and spatial characteristics of Korean apartments, and then synthesizes up-to-date empirical study results to examine how the diverse characteristics can be associated with the residents' social relations. The empirical evidence clarifies the effects of Korean apartments' characteristics on residents' social relations-the exclusive complex design, spatial configurations, shared spaces including community facilities, heights of the units, public/private housing types, social homogeneity, and community programs are all associated with social relations of the residents. Key methodological problems in current studies as well as implications for future apartment planning are highlighted.
Keywords
Housing; Homogeneity; Shared Space (traffic Engineering); Empirical Research; Sociocultural Theory; High-rise High-density; Korean Apartments; Residents; Social Relationships; Socio-spatial Characteristics; Built Environment; South-korea; Neighborhood; Community; Health; City; Place; Density; Seoul; Configuration Management; Apartments; Uniqueness; Social Relations; Empirical Analysis; Characteristics
Le, Vi T.; Dannenberg, Andrew L. (2020). Moving Toward Physical Activity Targets by Walking to Transit: National Household Transportation Survey, 2001-2017. American Journal Of Preventive Medicine, 59(3), E115 – E123.
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Abstract
Introduction: Public transportation systems can help people engage in physical activity. This study assesses sociodemographic correlates and trends in the daily time spent walking to and from transit in the U.S. from 2001 to 2017. Methods: This cross-sectional study used data from the 2001, 2009, and 2017 National Household Transportation Survey. Data were analyzed in 2019 to assess the daily level of physical activity attained solely by walking to and from transit. Regression models were used to examine predictors of daily transit-associated walking. Results: Compared with the full National Household Transportation Survey sample, transit users who walked to and from transit tended to be younger, from households earning <$25,000 per year, in areas with rail infrastructure, and did not have a household-owned car. Transit walkers spent a median of 20 minutes per day (95% CI=18.5, 21.5) walking to and from transit in 2017, compared with a median of 19 minutes (95% CI=17.5, 20.5) in 2001. Among transit walkers, daily transitassociated physical activity was 27% higher for those residing in areas with rail infrastructure (adjusted coefficient=1.27, 95% CI=1.11, 1.46) and 34% higher for those from households earning $99,999 per year (adjusted coefficient=1.34, 95% CI=1.15, 1.56). Conclusions: As documented in a growing literature, most public transit trips include at least some walking; thus, efforts to encourage transit use are favorable to public health. Continued monitoring by transportation surveys is important as new forms of mobility and changing demographics may impact future transit use and associated physical activity. (C) 2020 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Keywords
Physical Activity; Household Surveys; Public Transit; Cross-sectional Method; Public Health; Walking; Exercise; Research Funding; Transportation; Replacing Sedentary Time; Public-transit; Travel; Mortality; Adults; Health; Work
Shang, Luming; Aziz, Ahmed M. Abdel. (2020). Stackelberg Game Theory-Based Optimization Model for Design of Payment Mechanism in Performance-Based PPPs. Journal Of Construction Engineering And Management, 146(4).
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Abstract
Payment mechanisms lie at the heart of public-private partnership (PPP) contracts. A good design of the payment mechanism should consider the owner's goals in the project, allocate risks appropriately to stakeholders, and assure satisfactory performance by providing reasonable compensation to the private developer. This paper proposes a Stackelberg game theory-based model to assist public agencies in designing payment mechanisms for PPP transportation projects. The interests of both public and private sectors are considered and reflected by a bilevel objective function. The model aims to search for solutions that maximize a project's overall performance for the sake of social welfare while simultaneously maximizing return for the sake of private investment. A variable elimination method and genetic algorithm are used to solve the optimization model. A case study based on a real PPP project is discussed to validate the effectiveness of the proposed model. The solutions provided by the model reveal that the optimal payment mechanism structure could be established such that it would satisfy owners' requirements for overall project performance while optimizing project total payments to contractors.
Keywords
Construction Industry; Contracts; Financial Management; Game Theory; Genetic Algorithms; Investment; Optimisation; Organisational Aspects; Project Management; Public Administration; Transportation; Public-private Partnership Contracts; Good Design; Private Developer; Stackelberg Game Theory-based Model; Ppp Transportation Projects; Public Sectors; Private Sectors; Private Investment; Ppp Project; Optimal Payment Mechanism Structure; Project Performance; Project Total Payments; Stackelberg Game Theory-based Optimization Model; Performance-based Ppps; Public-private Partnerships; Analytic Hierarchy Process; Weighted Sum Method; Multiobjective Optimization; Algorithm; Incentives; Projects; Network; Success; Branch
Chalana, Manish. (2021). Whither the “Hindoo Invasion”? South Asians in the Pacific Northwest of the United States, 1907-1930. International Journal Of Regional & Local History, 16(1), 14 – 38.
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Abstract
The first decade of the twentieth century saw several thousand men migrate from India to the North American West Coast. While most settled in British Columbia or California, a smaller number moved to the US Pacific Northwest states of Washington and Oregon. A series of violent riots in 1907-8 drove many from the region. The basic contours of this population in the region after this time remain unclear. I uncover evidence that Indians persisted for a longer time period, and in more varied locations and occupations than some previous research suggests, but that ultimately violent exclusion led them to disappear almost entirely from the region. I investigate the conditions in which these men lived and toiled, and the ways in which they were viewed by the larger society, particularly in terms of evolving concepts of race and assimilation. [ABSTRACT FROM AUTHOR]; Copyright of International Journal of Regional & Local History is the property of Taylor & Francis 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.)
Keywords
Immigration; Indians; Oregon; Pacific Northwest; Punjabis; Sikh; South Asians; Washington