Skip to content

Teaching Life-Cycle Thinking in Construction Materials and Methods: Evaluation of and Deployment Strategies for Life-Cycle Assessment in Construction Engineering and Management Education

Lin, K. Y.; Levan, A.; Dossick, C. S. (2012). Teaching Life-Cycle Thinking in Construction Materials and Methods: Evaluation of and Deployment Strategies for Life-Cycle Assessment in Construction Engineering and Management Education. Journal Of Professional Issues In Engineering Education And Practice, 138(3), 163 – 170.

View Publication

Keywords

Sustainability; Design

PACPIM: New Decision-Support Model of Optimized Portfolio Analysis for Community-Based Photovoltaic Investment

Shakouri, Mahmoud; Lee, Hyun Woo; Choi, Kunhee. (2015). PACPIM: New Decision-Support Model of Optimized Portfolio Analysis for Community-Based Photovoltaic Investment. Applied Energy, 156, 607 – 617.

View Publication

Abstract

Inherent in large-scale photovoltaic (PV) investments is volatility that stems from a unique set of spatial factors, such as shading, building orientation, and roof slope, which can significantly affect both the level of risk and the return on investment. In order to systematically assess and manage the volatility, this study seeks to create a quantitative decision-support model: Portfolio Analysis for Community-based PV Investment Model (PACPIM). Focusing on residential PV systems, PACPIM determines optimized portfolios by applying the Mean Variance Portfolio theory. The model is intended to play an instrumental role in: (1) maximizing the hourly electricity output of PV systems; (2) minimizing the hourly volatility in electricity output; and (3) optimizing the risk-adjusted performance of community-based PV investment. The application and framework of PACPIM were deployed with an actual residential community consisting of 24 houses and their simulated data utilizing PVWatts (R) for estimating hourly electricity production. Results reveal that the optimized portfolios developed by PACPIM (1) increased annual electricity output of PV systems by 4.6%; (2) reduced the volatility in electricity output by 4.3%; and (3) offered the highest risk-adjusted performance among all possible portfolios based on the Sharpe ratios. This study is expected to effectively assist project owners and investors in systematically assessing their community-based PV projects and in developing optimized investment strategies. (C) 2015 Elsevier Ltd. All rights reserved.

Keywords

Photovoltaic Cells; Rate Of Return; Electricity; Dwellings; Electric Utilities; Community-based Investments; Decision-support Model; Mean–variance Portfolio Theory; Residential Photovoltaic Systems; Solar Energy; Decision Support Systems; Investment; Photovoltaic Power Systems; Large-scale Photovoltaic Investments; Spatial Factors; Shading; Building Orientation; Roof Slope; Return On Investment; Quantitative Decision-support Model; Portfolio Analysis For Community-based Pv Investment Model; Pacpim; Residential Pv Systems; Mean-variance Portfolio Theory; Hourly Electricity Output; Hourly Volatility; Risk-adjusted Performance; Hourly Electricity Production Estimation; Community-based Pv Projects; Optimized Investment Strategies; Romanian National Strategy; Renewable Energy; Public-attitudes; Wind Power; Pv Module; Performance; Implementation; Efficiency; Form; Economic Theory; Electricity Generation; Models; Risk; Shade; Solar Collectors

Sustainability in an Urbanizing Planet

Seto, Karen C.; Golden, Jay S.; Alberti, Marina; Turner, B. L., Ii. (2017). Sustainability in an Urbanizing Planet. Proceedings Of The National Academy Of Sciences Of The United States Of America, 114(34), 8935 – 8938.

View Publication

Keywords

Sustainability; Urbanization; Nature; Environment

Restructuration of Architectural Practice in Integrated Project Delivery (IPD): Two Case Studies

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.

View Publication

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

Case Study to Evaluate Work-Zone Safety Technologies in Highway Construction

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).

View Publication

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

Factors Affecting Material-Cart Handling in the Roofing Industry: Evidence for Administrative Controls

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).

View Publication

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

A Suggested Color Scheme for Reducing Perception-Related Accidents on Construction Work Sites

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.

View Publication

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

The Cloud beneath the Clouds

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)

A Probabilistic Portfolio-based Model For Financial Valuation Of Community Solar.

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.

View Publication

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

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.

View Publication

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