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Department: College of Built Environments

Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies

Lindell, Michael K.; Mumpower, Jeryl L.; Huang, Shih-kai; Wu, Hao-che; Samuelson, Charles D. (2015). Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies. Environmental Health Insights, 9, 13 – 21.

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Abstract

This study extends the Protective Action Decision Model, developed to address disaster warning responses in the context of natural hazards, to boil water advisories. The study examined 110 Boston residents' and 203 Texas students' expectations of getting sick through different exposure paths for contact with contaminated water. In addition, the study assessed respondents' actual implementation (for residents) or behavioral expectations (for students) of three different protective actions - bottled water, boiled water, and personally chlorinated water - as well as their demographic characteristics and previous experience with water contamination. The results indicate that people distinguish among the exposure paths, but the differences are small (one-third to one-half of the response scale). Nonetheless, the perceived risk from the exposure paths helps to explain why people are expected to consume (or actually consumed) bottled water rather than boiled or personally chlorinated water. Overall, these results indicate that local authorities should take care to communicate the relative risks of different exposure paths and should expect that people will respond to a boil water order primarily by consuming bottled water. Thus, they should make special efforts to increase supplies of bottled water in their communities during water contamination emergencies.

Keywords

Water Contamination; Exposure Paths; Risk Perception; Protective Action

Time-Cost Performance Effect of Change Orders from Accelerated Contract Provisions

Choi, Kunhee; Lee, Hyun Woo; Bae, Junseo; Bilbo, David. (2016). Time-Cost Performance Effect of Change Orders from Accelerated Contract Provisions. Journal Of Construction Engineering And Management, 142(3).

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Abstract

Accelerated contract provisions (ACPs) such as cost-plus-time (A+B) and incentives/disincentives (I/D) are increasingly common, yet very little is known about their pure time-cost performance effects on change orders. To fill this large knowledge gap, a two-stage research methodology drawing on 1,372 highway improvement projects completed in California was adopted for this study. The Stage I study investigated the marginal change-order impacts of two ACPs, pure A+B and I/D combined with A+B. How ACP change orders affect projects' time-cost performance was numerically modeled and successfully validated over the Stage II study. The results clearly showed that both ACPs led to more schedule-change and cost-change orders than conventionally contracted projects, whereas I/D combined with A+B performed significantly better than pure A+B in terms of the magnitude of schedule-change orders. This conveys an important recommendation to state transportation agencies (STAs) that A+B be used with an I/D provision. The results and numerical models of this study would help STAs better assess and justify the impact of change orders on the duration and cost of projects, enabling them to more effectively use contingency amounts. Use of the models can also benefit contractors requesting a change order because the models can provide them with advanced knowledge of the probable time-cost growth rates specifically for the pursued ACP. (C) 2015 American Society of Civil Engineers.

Keywords

Construction Industry; Contracts; Costing; Incentive Schemes; Numerical Analysis; Order Processing; Performance Evaluation; Roads; Scheduling; Time Management; Transportation; Projects Time-cost Performance Effect; Cost-change Order; Accelerated Contract Provision; Knowledge Gap; California; Acp; Schedule-change Order; State Transportation Agency; Numerical Model; Sta; Incentive; Highway Improvement Project; Labor Productivity; Construction; Impact; Model; Projects; Change Order; Highway Rehabilitation; Decision Modeling; Regression; Validation; Contracting

Spatial Energetics Integrating Data from GPS, Accelerometry, and GIS to Address Obesity and Inactivity

James, Peter; Jankowska, Marta; Marx, Christine; Hart, Jaime E.; Berrigan, David; Kerr, Jacqueline; Hurvitz, Philip M.; Hipp, J. Aaron; Laden, Francine. (2016). Spatial Energetics Integrating Data from GPS, Accelerometry, and GIS to Address Obesity and Inactivity. American Journal Of Preventive Medicine, 51(5), 792 – 800.

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Abstract

To address the current obesity and inactivity epidemics, public health researchers have attempted to identify spatial factors that influence physical inactivity and obesity. Technologic and methodologic developments have led to a revolutionary ability to examine dynamic, high-resolution measures of temporally matched location and behavior data through GPS, accelerometry, and GIS. These advances allow the investigation of spatial energetics, high-spatiotemporal resolution data on location and time-matched energetics, to examine how environmental characteristics, space, and time are linked to activity-related health behaviors with far more robust and detailed data than in previous work. Although the transdisciplinary field of spatial energetics demonstrates promise to provide novel insights on how individuals and populations interact with their environment, there remain significant conceptual, technical, analytical, and ethical challenges stemming from the complex data streams that spatial energetics research generates. First, it is essential to better understand what spatial energetics data represent, the relevant spatial context of analysis for these data, and if spatial energetics can establish causality for development of spatially relevant interventions. Second, there are significant technical problems for analysis of voluminous and complex data that may require development of spatially aware scalable computational infrastructures. Third, the field must come to agreement on appropriate statistical methodologies to account for multiple observations per person. Finally, these challenges must be considered within the context of maintaining participant privacy and security. This article describes gaps in current practice and understanding and suggests solutions to move this promising area of research forward. (C) 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Keywords

Physical-activity Levels; Built Environment; Activity Monitors; Travel Behavior; Health Research; Neighborhood; Exposure; Validation; Children; Design

Physical Activity and the Built Environment in Residential Neighborhoods of Seoul and Seattle: An Empirical Study Based on Housewives’ GPS Walking Data and Travel Diaries

Park, Sohyun; Choi, Yeemyung; Seo, Hanlim; Moudon, Anne Vernez; Bae, C. -h. Christine; Baek, So-ra. (2016). Physical Activity and the Built Environment in Residential Neighborhoods of Seoul and Seattle: An Empirical Study Based on Housewives’ GPS Walking Data and Travel Diaries. Journal Of Asian Architecture And Building Engineering, 15(3), 471 – 478.

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Abstract

This paper is based on a collaborative pilot-study to ascertain the characteristic walking patterns and neighborhood features in residential areas of Seoul, Korea and Seattle, USA. As for sample sites, four case neighborhoods were selected: two from Seoul and two from in and outside of the Seattle-Shoreline areas. As for participants, thirty Korean housewives in Seoul and thirty Korean-American housewives in the Seattle area were selected respectively, and their socio-demographic characteristics, GPS records, and travel diary data for seven days were collected and analyzed. Considering the typical rainy seasons in the two cities, data collections, including the physical activity assessment by GPS devices, were carried out from May to June and from September to October in Seoul, and from July to October in Seattle during the year 2010. Noteworthy research findings include the following: Korean participants in Seoul walk about 2.6 km on average per day, while Korean-American participants in Seattle walk about 400m on average per day. In the case sites of Seoul, 75% of grocery shopping activities happen within the neighborhood by walking, while only 17% of those activities on foot happen in the case sites of Seattle. As for the most walking activity, about 70% of total walking amounts are related to utilitarian walking in Seoul sites, while 50% of total walking are related to recreational walking in Seattle sites. Recreational walking and utilitarian walking occur separately in Seattle sites, while the two walking types are often combined in Seoul sites, which also contribute to more walking amounts and farther walking distances in Seoul sites. This paper empirically confirms the widely held assumptions in part that residents in Seoul, a relatively high-density and high mixed-use city, walk more than those in Seattle, a relatively low-density and low mixed-use city. This paper also recognizes that in the case of both cities, more walking activities occur in the neighborhood built environment, where finely-grained street networks, small lots and blocks, various pedestrian destinations, public transit access, etc are provided in close connection. The amount and frequency of walking activities, as well as the fineness of neighborhood features, however, are remarkably different in the two cities, whose implications deserve in-depth exploration in further studies.

Keywords

Urban Design; Physical Activity; Neighborhood Environment; Objective Measures; Gps Walking Data; International Comparative Study

The Influence of Urban Design Packages on Home Values

Bitter, Christopher; Krause, Andy. (2017). The Influence of Urban Design Packages on Home Values. International Journal Of Housing Markets And Analysis, 10(2), 184 – 203.

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Abstract

Purpose The purpose of this study is to examine the impact of neighborhood design templates on residential home values in King County, WA, USA. Previous research examines a number of individual design factors; this study combines these factors into typologies and tests for the impacts of the composite set of design features. Design/methodology/approach The study analyzes over 27,000 home sales with a hedonic price model to measure the impacts across three large, regional submarkets. Neighborhood design categories are developed using a cluster analysis on a set of individual neighborhood attributes. Findings The key finding from this research is that the impact of more traditional (“urban”) design packages on home values is highly contextual. For the older and denser neighborhoods in the study area, a more traditional design results in a significantly positive impact on home values. In the new and more suburban regions of the study area, this effect is not found. Originality/value Prior work focused on valuing design attributes individually. The study argues that neighborhood design is better conceived of as a “package”, as the value of a given design element may depend on other co-located attributes. This is the first study, to the authors’ knowledge, to treat physical neighborhood design variables as a composite whole and to attempt to value their impact on home values as such.

Keywords

Regional Development; Packages; Cluster Analysis; Suburban Areas; Residential Areas; Housing; Design; Connectivity; Property Values; Urban Planning; Emission Standards; Neighborhoods; Urban Areas; Influence; Household Utilities; Design Factors; Regional Analysis; Housing Prices; Land Use; Tax Assessments; Urbanism

Differences in Behavior, Time, Location, and Built Environment between Objectively Measured Utilitarian and Recreational Walking

Kang, Bumjoon; Moudon, Anne V.; Hurvitz, Philip M.; Saelens, Brian E. (2017). Differences in Behavior, Time, Location, and Built Environment between Objectively Measured Utilitarian and Recreational Walking. Transportation Research: Part D, 57, 185 – 194.

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Abstract

Objectives: Utilitarian and recreational walking both contribute to physical activity. Yet walking for these two purposes may be different behaviors. We sought to provide operational definitions of utilitarian and recreational walking and to objectively measure their behavioral, spatial, and temporal differences in order to inform transportation and public health policies and interventions. Methods: Data were collected 2008-2009 from 651 Seattle-King County residents, wearing an accelerometer and a GPS unit, and filling-in a travel diary for 7 days. Walking activity bouts were classified as utilitarian or recreational based on whether walking had a destination or not. Differences between the two walking purposes were analyzed, adjusting for the nested structure of walking activity within participants. Results: Of the 4905 observed walking bouts, 87.4% were utilitarian and 12.6% recreational walking. Utilitarian walking bouts were 45% shorter in duration (-12.1 min) and 9% faster in speed (+0.3 km/h) than recreational walking bouts. Recreational walking occurred more frequently in the home neighborhood and was not associated with recreational land uses. Utilitarian walking occurred in areas having higher residential, employment, and street density, lower residential property value, higher area percentage of mixed-use neighborhood destinations, lower percentage of parks/trails, and lower average topographic slope than recreational walking. Conclusion: Utilitarian and recreational walking are substantially different in terms of frequency, speed, duration, location, and related built environment. Policies that promote walking should adopt type-specific strategies. The high occurrence of recreational walking near home highlights the importance of the home neighborhood for this activity.

Keywords

Walking; Utilitarianism; Recreation; Behavioral Assessment; Built Environment; Physical Activity Measurement; Accelerometer; Active Transportation; Gps; Home And Non-home Based Walking; Pedestrian; Physical-activity; Us Adults; Accelerometer Data; Trip Purpose; Urban Form; Travel; Neighborhood; Distance; System

Lighting Energy Consumption in Ultra-Low Energy Buildings: Using a Simulation and Measurement Methodology to Model Occupant Behavior and Lighting Controls

Zhu, Panyu; Gilbride, Michael; Yan, Da; Sun, Hongshan; Meek, Christopher. (2017). Lighting Energy Consumption in Ultra-Low Energy Buildings: Using a Simulation and Measurement Methodology to Model Occupant Behavior and Lighting Controls. Building Simulation, 10(6), 799 – 810.

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Abstract

As building owners, designers, and operators aim to achieve significant reductions in overall energy consumption, understanding and evaluating the probable impacts of occupant behavior becomes a critical component of a holistic energy conservation strategy. This becomes significantly more pronounced in ultra-efficient buildings, where system loads such as heating, cooling, lighting, and ventilation are reduced or eliminated through high-performance building design and where occupant behavior-driven impacts reflect a large portion of end-use energy. Further, variation in behavior patterns can substantially impact the persistence of any performance gains. This paper describes a methodology of building occupant behavior modeling using simulation methods developed by the Building Energy Research Center (BERC) at Tsinghua University using measured energy consumption data collected by the University of Washington Integrated Design Lab (UW IDL). The Bullitt Center, a six-story 4831 m(2) (52,000 ft(2)) net-positive-energy urban office building in Seattle, WA, USA, is one of the most energy-efficient buildings in the world (2013 WAN Sustainable Building of the Year Winner). Its measured energy consumption in 2015 was approximately 34.8 kWh/(m(2)a (TM) yr) (11 kBtu/(ft(2)a (TM) yr)). Occupant behavior exerts an out-sized influence on the energy performance of the building. Nearly 33% of the end-use energy consumption at the Bullitt Center consists of unregulated miscellaneous electrical loads (plug-loads), which are directly attributable to occupant behavior and equipment procurement choices. Approximately 16% of end-use energy is attributable to electric lighting which is also largely determined by occupant behavior. Key to the building's energy efficiency is employment of lighting controls and daylighting strategies to minimize the lighting load. This paper uses measured energy use in a 330 m(2) (3550 ft(2)) open office space in this building to inform occupant profiles that are then modified to create four scenarios to model the impact of behavior on lighting use. By using measured energy consumption and an energy model to simulate the energy performance of this space, this paper evaluates the potential energy savings based on different occupant behavior. This paper describes occupant behavior simulation methods and evaluates them using a robust dataset of 15 minute interval sub-metered energy consumption data. Lighting control strategies are compared via simulation results, in order to achieve the best match between occupant schedules, controls, and energy savings. Using these findings, we propose a simulation methodology that incorporates measured energy use data to generate occupant schedules and control schemes with the ultimate aim of using simulation results to evaluate energy saving measures that target occupant behavior.

Keywords

Control-systems; Patterns; Offices; Lighting Control; Ultra-low Energy Building; Occupant Behavior; Building Simulation; Energy Consumption

Feasibility of Using QR Codes in Highway Construction Document Management

Lee, Hyun Woo; Harapanahalli, Bharat Anand; Nnaji, Chukwuma; Kim, Jonghyeob; Gambatese, John. (2018). Feasibility of Using QR Codes in Highway Construction Document Management. Transportation Research Record, 2672(26), 114 – 123.

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Abstract

Highway construction occasionally takes place in remote locations, making its document management challenging especially when frequent document revisions occur. With the recent advancement of smartphones and tablets, Quick Response (QR) codes can provide project teams rapid and reliable access to up-to-date documents required for field operations. As a result, the use of QR codes can lead to a reduced need for traveling or meeting for document revisions, and reduce the amount of hardcopy documents and storage space. Despite the potential for significant benefits, there have been few studies aimed at assessing the feasibility of using QR codes in highway construction. In response, the objective of the study was to investigate the benefits of and barriers to using QR codes in highway construction for document management. To conduct the study, first a multi-step process was used, involving an online survey and interviews, with a goal of determining the status quo of highway construction in terms of document management and mobile information technology (IT). The results indicate that hardcopy documentation is still the most prevalent form of document management in highway construction, and hence there is an opportunity for implementing QR codes in conjunction with mobile IT. In the second part of the study, a time study using a real-world infrastructure project was conducted based on three activities: detail look up, specification check, and version check. As a result, the study found statistical evidence that using QR codes can lead to significant time savings.

Keywords

Highway Planning; Information Services; Road Construction; Document Management; Field Operation; Highway Construction; Infrastructure Project; Online Surveys; Quick Response Code; Remote Location; Statistical Evidence

Is There a Limit to Bioretention Effectiveness? Evaluation of Stormwater Bioretention Treatment Using a Lumped Urban Ecohydrologic Model and Ecologically Based Design Criteria

Wright, Olivia M.; Istanbulluoglu, Erkan; Horner, Richard R.; Degasperi, Curtis L.; Simmonds, Jim. (2018). Is There a Limit to Bioretention Effectiveness? Evaluation of Stormwater Bioretention Treatment Using a Lumped Urban Ecohydrologic Model and Ecologically Based Design Criteria. Hydrological Processes, 32(15), 2318 – 2334.

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Abstract

In this study, we developed the urban ecohydrology model (UEM) to investigate the role of bioretention on watershed water balance, runoff production, and streamflow variability. UEM partitions the land surface into pervious, impervious, and bioretention cell fractions. Soil moisture and vegetation dynamics are simulated in pervious areas and bioretention cells using a lumped ecohydrological approach. Bioretention cells receive runoff from a fraction of impervious areas. The model is calibrated in an urban headwater catchment near Seattle, WA, USA, using hourly weather data and streamflow observations for 3years. The calibrated model is first used to investigate the relationship between streamflow variability and bioretention cell size that receives runoff from different values of impervious area in the watershed. Streamflow variability is quantified by 2 indices, high pulse count (HPC), which quantifies the number of flow high pulses in a water year above a threshold, and high pulse range (HPR), which defines the time over which the pulses occurred. Low values of these indices are associated with improved stream health. The effectiveness of the modelled bioretention facilities are measured by their influence on reducing HPC and HPR and on flow duration curves in comparison with modelled fully forested conditions. We used UEM to examine the effectiveness of bioretention cells under rainfall regimes that are wetter and drier than the study area in an effort to understand linkages between the degree of urbanization, climate, and design bioretention cell size to improve inferred stream health conditions. In all model simulations, limits to the reduction of HPC and HPR indicators were reached as the size of bioretention cells grew. Bioretention was more effective as the rainfall regime gets drier. Results may guide bioretention design practices and future studies to explore climate change impacts on bioretention design and management.

Keywords

Performance Assessment; Hydrologic Alteration; Automated Techniques; Management-practices; Land-cover; Streams; Water; Impact; Area; Runoff; Bioretention; Ecohydrology; Green Infrastructure; Stormwater; Stream Health; Urban Hydrology; Evaluation; Urbanization; Watersheds; Soil Moisture; Water Balance; Stream Flow; Design; Variability; Ecological Monitoring; Computer Simulation; Storms; Climate Change; Duration; Water Runoff; Flow Duration Curves; Flow Duration; Cell Size; Soils; Duration Curves; Rainfall; Rivers; Cells; Headwaters; Surface Runoff; Dynamics; Rainfall Regime; Catchment Area; Design Criteria; Environmental Impact; Retention Basins; Soil Dynamics; Stream Discharge; Climatic Changes; Meteorological Data; Headwater Catchments

A Mixed VR and Physical Framework to Evaluate Impacts of Virtual Legs and Elevated Narrow Working Space on Construction Workers Gait Pattern

Habibnezhad, M.; Puckett, J.; Fardhosseini, M.S.; Pratama, L.A. (2019). A Mixed VR and Physical Framework to Evaluate Impacts of Virtual Legs and Elevated Narrow Working Space on Construction Workers Gait Pattern. Arxiv, 7 pp.

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Abstract

It is difficult to conduct training and evaluate workers' postural performance by using the actual job site environment due to safety concerns. Virtual reality (VR) provides an alternative to create immersive working environments without significant safety concerns. Working on elevated surfaces is a dangerous scenario, which may lead to gait and postural instability and, consequently, a serious fall. Previous studies showed that VR is a promising tool for measuring the impact of height on the postural sway. However, most of these studies used the treadmill as the walking locomotion apparatus in a virtual environment (VE). This paper was focused on natural walking locomotion to reduce the inherent postural perturbations of VR devices. To investigate the impact of virtual height on gait characteristics and keep the level of realism and feeling of presence at their highest, we enhanced the first-person-character model with "virtual legs". Afterward, we investigated its effect on the gait parameters of the participants with and without the presence of height. To that end, twelve healthy adults were asked to walk on a virtual loop path once at the ground level and once at the 17th floor of an unfinished structure. By quantitatively comparing the participants' gait pattern results, we observed a decrease in the stride length and increase in the gait duration of the participants exposed to height. At the ground level, the use of the enhanced model reduced participants' average stride length and height. The results of this study help us understand users' behaviors when they were exposed to elevated surfaces and establish a firm ground for gait stability analysis for the future height-related VR studies. We expect this developed VR platform can generate reliable results of VR application in more construction safety studies.

Keywords

Civil Engineering Computing; Construction Industry; Gait Analysis; Medical Computing; Occupational Safety; Virtual Reality; Construction Safety Studies; Mixed Vr; Virtual Legs; Construction Workers Gait Pattern; Immersive Working Environments; Postural Instability; Serious Fall; Postural Sway; Walking Locomotion Apparatus; Natural Walking Locomotion; Inherent Postural Perturbations; Vr Devices; Virtual Height; First-person-character Model; Gait Parameters; Virtual Loop Path; Stride Length; Gait Duration; Gait Stability Analysis; Safety Concerns; Vr Platform; Height-related Vr Studies