Abdirad, Hamid; Dossick, Carrie S. (2019). Restructuration of Architectural Practice in Integrated Project Delivery (IPD): Two Case Studies. Engineering, Construction And Architectural Management, 26(1), 104 – 117.
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Abstract
Purpose The purpose of this paper is to clarify that while integrated project delivery (IPD) methods can be momenta for restructuring architectural practice, they do not predetermine specific patterns of restructuration for the roles, responsibilities and services of architects. Design/methodology/approach This paper is based on a multiple case study design; two IPD projects were theoretically sampled and studied. The data collection methods included semi-structured interviews and observations. An inductive data analysis approach was applied to frame the phenomena, conduct cross-case comparisons and develop propositions. Findings While IPD implementations set expectations for new structures for practices, it is the project participants' situated decisions that lead to the restructuration of some dimensions of architectural practice. The dimensions in this study included team formation, design leadership and collaboration and architectural services. IPD project participants locally changed and redefined conventional roles, responsibilities and project artifacts (e.g. drawings and models) that concerned design development and coordination. Practical implications - IPD context, by itself, does not predetermine a fixed pattern of change in establishing designers' roles, responsibilities and services because restructuration is highly negotiated amongst the IPD parties and can lead to different responses to this contractual setting. Contracts set expectations for collaborative behavior, but the fulfillment of these expectations is situated and emerging as project participants negotiate to develop practices. Originality/value - While IPD research and guidelines aim to provide recipes for IPD implementation, this study contributes to the body of knowledge by clarifying that IPD is a context in which unprecedented ways of practice restructuration could emerge.
Keywords
Construction Industry; Contracts; Data Analysis; Human Resource Management; Innovation Management; Organisational Aspects; Project Management; Team Working; Architectural Practice; Case Studies; Integrated Project Delivery Methods; Specific Patterns; Responsibilities; Design/methodology; Multiple Case Study Design; Ipd Projects; Data Collection Methods; Observations; Inductive Data Analysis Approach; Cross-case Comparisons; Ipd Implementation; Practices; Design Leadership; Architectural Services; Ipd Project Participants; Conventional Roles; Project Artifacts; Concerned Design Development; Coordination; Practical Implications; Ipd Context; Designers; Ipd Parties; Different Responses; Practice Restructuration; Contractors; Ipd; Architecture; Integration; Design Management; Case Study; Integrated Project Delivery; Integrated Practice; Restructuration
Nnaji, Chukwuma; Karakhan, Ali A.; Gambatese, John; Lee, Hyun Woo. (2020). Case Study to Evaluate Work-Zone Safety Technologies in Highway Construction. Practice Periodical On Structural Design And Construction, 25(3).
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Abstract
The construction industry is known for its conservative approach toward adopting new, emerging technologies. This conservative approach for adopting technology is caused by multiple factors including the lack of adequate resources to guide construction practitioners in the process of evaluating whether a construction firm should adopt a certain technology or not. Previous studies have already proposed rigorous protocols for evaluating work-zone technologies, but the implementation of such protocols is still unclear to many construction practitioners. The objective of this study is to provide a case study example of how evaluation protocols can be used in practice to determine whether a firm should adopt a certain work-zone technology. The case study focused on assessing the usefulness of commercially available work-zone intrusion alert technologies (WZIATs). The results of the evaluation revealed that some WZIATs could be more attractive to construction organizations and agencies in terms of providing louder alarms, being more mobile, and allowing a higher transmission range. The case study example discussed in this study is expected to provide invaluable practical information to practitioners in the construction industry interested in evaluating and adopting emerging technologies.
Keywords
Construction Industry; Mobile Radio; Occupational Safety; Road Building; Road Safety; Highway Construction; Conservative Approach; Construction Practitioners; Construction Firm; Rigorous Protocols; Work-zone Technology; Case Study Example; Evaluation Protocols; Commercially Available Work-zone Intrusion Alert Technologies; Construction Organizations; Evaluate Work-zone Safety Technologies; Speed; Signs; Work Zone; Safety Technology; Intrusion Alert; Evaluation Protocol
Zhang, Zhenyu; Lin, Ken-yu; Lin, Jia-hua. (2021). Factors Affecting Material-Cart Handling in the Roofing Industry: Evidence for Administrative Controls. International Journal Of Environmental Research And Public Health, 18(4).
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Abstract
Material-cart handling can be strenuous and lead to overexertion injuries. The aim of this study is to produce a thorough understanding of how the cart condition, tire type, physical environment-related factors, and load interact to influence the ergonomics and productivity of cart handling. Eighteen roofing carts with different conditions, tires, and loads were tested by one subject on three laboratory tracks: one L-shaped, one with ramps within constrained spaces, and one with obstacles within constrained spaces. A multiple linear regression analysis was performed to quantify the main and interaction effects of the factors of interest on the cart operations. The research findings confirm that using aged carts increases the injury risk by as much as 30.5% and decreases productivity by 35.4%. Our study also highlights the necessity of keeping an open space for cart operation; the travel distance from a cart to a ramp/obstacle should be greater than 61 cm. Finally, the results suggest the at-risk thresholds for different ramp slopes and obstacle heights, and the safe load capacities for the various working circumstances that are common on construction sites. The evidence created in this study can be translated into administrative controls for cart handling to reduce overexertion injuries and enhance performance.
Keywords
Overexertion In Pulling And Pushing; Material Cart Handling; Roof Construction; Ergonomic Risk Factors; Administrative Control
Yi, June-Seong; Kim, Yong-Woo; Kim, Ki-Aeng; Koo, Bonsang. (2012). A Suggested Color Scheme for Reducing Perception-Related Accidents on Construction Work Sites. Accident Analysis And Prevention, 48, 185 – 192.
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Abstract
Changes in workforce demographics have led to the need for more sophisticated approaches to addressing the safety requirements of the construction industry. Despite extensive research in other industry domains, the construction industry has been passive in exploring the impact of a color scheme: perception-related accidents have been effectively diminished by its implementation. The research demonstrated that the use of appropriate color schemes could improve the actions and psychology of workers on site, thereby increasing their perceptions of potentially dangerous situations. As a preliminary study, the objects selected by rigorous analysis on accident reports were workwear, safety net, gondola, scaffolding, and safety passage. The colors modified on site for temporary facilities were adopted from existing theoretical and empirical research that suggests the use of certain colors and their combinations to improve visibility and conspicuity while minimizing work fatigue. The color schemes were also tested and confirmed through two workshops with workers and managers currently involved in actual projects. The impacts of color schemes suggested in this paper are summarized as follows. First, the color schemes improve the conspicuity of facilities with other on site components, enabling workers to quickly discern and orient themselves in their work environment. Secondly, the color schemes have been selected to minimize the visual work fatigue and monotony that can potentially increase accidents. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords
Construction Industry Accidents; Industrial Hygiene; Industrial Safety; Empirical Research; Sensory Perception; Work Environment; Demographic Surveys; Job Performance; Color Scheme; Construction Industry; Labor Demography; Perception-related Accident; Accident Prevention; Accidents; Demography; Human Resource Management; Population Statistics; Color Schemes; Construction Works; Dangerous Situations; Rigorous Analysis; Safety Requirements; Temporary Facilities; Work Environments; Psychological Climate; Drivers; Emotion; Model
Vitro, Kristen A.; Whittington, Jan. (2015). The Cloud beneath the Clouds. Planning, 81(1), 35 – 35.
Abstract
The article discusses the proliferation of cloud computing data centers in Seattle, Washington. It also discusses the reasons behind the selection of the city by cloud computing data centers as site locations which include the availability of inexpensive but abundant sources of electricity, classification of dams as a critical infrastructure, and cooler climate. Another reason discussed is the planning and economic development practiced by municipalities to attract businesses in the area.
Keywords
Cloud Computing; Server Farms (computer Network Management); Industrial Location; Infrastructure (economics); Urban Planning; Economic Development; Seattle (wash.); Washington (state)
Shakouri, Mahmoud; Lee, Hyun Woo; Kim, Yong-woo. (2017). A Probabilistic Portfolio-Based Model for Financial Valuation of Community Solar. Applied Energy, 191, 709 – 726.
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Abstract
Community solar has emerged in recent years as an alternative to overcome the limitations of individual rooftop photovoltaic (PV) systems. However, there is no existing model available to support probabilistic valuation and design of community solar based on the uncertain nature of system performance over time. In response, the present study applies the Mean-Variance Portfolio Theory to develop a probabilistic model that can be used to increase electricity generation or reduce volatility in community solar. The study objectives include identifying the sources of uncertainties in PV valuation, developing a probabilistic model that incorporates the identified uncertainties into portfolios, and providing potential investors in community solar with realistic financial indicators. This study focuses on physical, environmental, and financial uncertainties to construct a set of optimized portfolios. Monte Carlo simulation is then performed to calculate the return on investment (ROI) and the payback period of each portfolio. Lastly, inclusion vs. exclusion of generation and export tariffs are compared for each financial indicator. The results show that the portfolio with the maximum output offers the highest ROI and shortest payback period while the portfolio with the minimum risk indicates the lowest ROI and longest payback period. This study also reveals that inclusion of tariffs can significantly influence the financial indicators, even more than the other identified uncertainties. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords
Solar Energy; Photovoltaic Power Systems; Monte Carlo Method; Market Volatility; Energy Economics; Community Solar; Monte Carlo Simulation; Photovoltaic Systems; Portfolio Theory; Uncertainty; Environmental Uncertainties; Financial Indicator; Financial Uncertainties; Physical Uncertainties; Identified Uncertainties; Probabilistic Model; Mean-variance Portfolio Theory; Probabilistic Valuation; Individual Rooftop Photovoltaic Systems; Financial Valuation; Probabilistic Portfolio-based Model; Investment; Monte Carlo Methods; Photovoltaic Cells; Risk Analysis; Tariffs; Resolution Lidar Data; Electricity Consumption; Pv Systems; Autoregressive Models; Potential Assessment; Generation Systems; Neural-networks; Energy; Buildings; Economic Theory; Electricity; Exports; Probabilistic Models; Risk
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
Parsaee, Mojtaba; Demers, Claude M. H.; Lalonde, Jean-francois; Potvin, Andre; Inanici, Mehlika; Hebert, Marc. (2020). Human-Centric Lighting Performance of Shading Panels in Architecture: A Benchmarking Study with Lab Scale Physical Models Under Real Skies. Solar Energy, 204, 354 – 368.
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Abstract
This study investigates shading panels' (SPs) impacts on daylighting features in a lab scale model in terms of parameters representing potential human eyes' biological responses identified as image forming (IF) and non-image forming (NIF). IF responses enable vision and NIF responses regulate internal body clocks known as circadian clocks. Human-centric lighting evaluates photopic units, representing IF responses, and melanopic units representing NIF responses, combined with correlated color temperature (CCT) of light for potential biological effects. SPs' impacts on such parameters of daylighting have not yet been studied. Previous research mostly studied panels' impacts on visual comfort and glare related to IF responses. This research explores the impact of SPs' color, reflectance, orientation, and openness on photopic and melanopic units and CCT of daylighting inside a 1:50 physical scale model of a space. Approximately 40 prototypes of SPs were evaluated. An experimental setup was designed under outdoor daylighting conditions to capture high dynamic range (HDR) images inside the model. HDR images were post processed to calculate and render the distribution of photopic and melanopic units, melanopic/photopic (M/P) ratios and CCTs in the captured viewpoint of the model. Results reveal the behavior of SPs' color, reflectance, orientation, and openness in modifying daylighting parameters related to biological responses. Bluish panels, in particular, increase daylighting melanopic units and CCTs whereas reddish panels increase photopic units and reduce CCTs. The research results were discussed to provide an outline for future developments of panels to adapt daylighting to occupants' IF and NIF responses.
Keywords
Models & Modelmaking; Shades & Shadows; Daylighting; Color Temperature; Benchmarking (management); Ecological Houses; Eye Tracking; Circadian Rhythms; Adaptive Design; Healthy Lighting; High Performance Façade; Photobiology; Responsive Building; Design; Sensitivity; Illuminance; Systems; Spaces; Impact; Glare; High Performance Facade; Reflectance; Scale Models; Biological Effects; Human Performance; Prototypes; Parameter Modification; Lighting; Shading; Eye (anatomy); Color; Parameter Identification; Light Effects; Panels; Mathematical Models; Images; Biological Clocks; Orientation
Zou, Tianqi; Aemmer, Zack; Mackenzie, Don; Laberteaux, Ken. (2022). A Framework for Estimating Commute Accessibility and Adoption of Ridehailing Services Under Functional Improvements from Vehicle Automation. Journal Of Transport Geography, 102.
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Abstract
This paper develops an analytical framework to estimate commute accessibility and adoption of various ridehailing service concepts across the US by synthesizing individual commute trips using national Longitudinal Employer-Household Dynamics Origin-Destination Employment Statistics (LODES) data. Focusing on potential improvements in cost and time that could be enabled by vehicle automation, we use this modeling framework to simulate a lower-price autonomous service (e.g., 50% or 75% lower) with variable wait times and implementation levels (solo, pooled, and first/last mile transit connections services, alone or in combination) to determine how they might affect adoption rates. These results are compared across metrics of accessibility and trip density, as well as socioeconomic factors such as household income. We find - unsurprisingly - that major cities (e.g. New York, Los Angeles, and Chicago) support the highest adoption rates for ridehailing services. Decreases in price tend to increase market share and accessibility. The effect of a decrease in price is more drastic for lower income groups. The proposed method for synthesizing trips using the LODES contributes to current travel demand forecasting methods and the proposed analytic framework can be flexibly implemented with any other mode choice model, extended to non-commute trips, or applied to different levels of geographic aggregation.
Keywords
Choice Of Transportation; Demand Forecasting; Poor People; Adoption; Price Cutting; Metropolis; Employment Statistics; Los Angeles (calif.); New York (state); Chicago (ill.); Accessibility; Autonomous Vehicles; New Mobility Services; Ridehailing; Travel Demand; Preferences
Assistant Professor, Department of Construction Management
Fred is an Assistant Professor with the Department of Construction Management (CM) at the University of Washington (UW). Prior to joining UW in September 2021, he was an Assistant Professor at Texas State University in San Marcos, TX where he taught and performed research in the areas of concrete materials, durability, and sustainable infrastructure construction. He received his PhD in Civil Engineering from the University of Texas at Austin in 2016.
Dr. Aguayo is interested in research application that contribute to facilitating the implementation of sustainable and novel cement-based systems in infrastructure and building applications such as alternative cement binders, supplementary cementing materials (SCMs), recycled aggregates, and high performing concretes. His research group focuses on evaluating and characterizing deterioration processes in new and existing cementitious materials, while also developing test methods to predict and enhance their performance and durability in the field. He primarily examines durability-related issues in cement-based materials such as corrosion, carbonation, ASR, sulfate attack, and early-age volume changes.
Dr. Aguayo is a well-established researcher with over 13 years of experience and over $1.2M in funded research projects as either PI or Co-PI since 2016. His work has been supported by both private industry and public agencies including LarfargeHolcim, Texas DOT, Minnesota DOT, New Mexico DOT, National Research Road Alliance (NRRA), and the Portland Cement Association (PCA). He is an active member of the American Concrete Institute and ASTM International, and participates in several committees related to concrete durability (ACI 201) and material science of cementitious systems (ACI 236).