Min, Yohan; Lee, Hyun Woo. (2023). Characterization of Vulnerable Communities in Terms of the Benefits and Burdens of the Energy Transition in Pacific Northwest Cities. Journal of Cleaner Production.
View Publication
Abstract
Energy transition to renewable sources has occurred along with the development of various clean energy policies aimed at decarbonization and electrification. However, the transition can inadvertently lead to social inequity resulting in increasing burdens on vulnerable communities. Although many studies have tried to define and identify vulnerable communities, there has been no study specifically aimed at characterizing vulnerable communities in terms of the benefits and burdens of such energy transition. In response, the objective of this study is to characterize vulnerable communities by examining rooftop solar adoption and energy expenditure using spatial and mixed-effect models. Rooftop solar adoption operationalizes energy resilience and benefits, and energy expenditure operationalizes energy dependence and burdens of the transition. The study also investigates the link between rooftop solar adoption and energy expenditure by considering city-level variability in three Pacific Northwest cities. The results show that Bellevue has 50.4% less rooftop solar adoption than Portland, while Portland has 16.1% or $223 more energy expenditure than Seattle. On average, an increase in annual energy expenditure of $431 is associated with 29% increase in rooftop solar adoption, specifically Bellevue, Seattle, and Portland by 21.4%, 39.1%, and 26.2%, respectively, but not vice versa. Furthermore, the group of communities more vulnerable in housing attributes has 15.2% less rooftop solar adoption than the group of more vulnerable communities in socioeconomic attributes. In addition, the city centers, commercial areas, or mid-rise and high-rise zones are found to have lower rooftop solar adoption and energy expenditure than other areas. The results suggest that policymakers should consider between-city variability when identifying vulnerable communities. Policies should also be tailored to local communities based on their attributes as communities with similar attributes tend to cluster together. Furthermore, policymakers should focus more on housing and built environment attributes to promote resilient communities.
Osburn, Laura; Lee, Hyun Woo; Gambatese, John A. (2022). Formal Prevention through Design Process and Implementation for Mechanical, Electrical, and Plumbing Worker Safety. Journal Of Management In Engineering, 38(5).
View Publication
Abstract
There are many studies that focus on Prevention through Design (PtD) for construction workers and developing formalized PtD processes for construction projects. However, few studies have aimed at developing a formalized PtD process for mechanical/electrical/plumbing (MEP) worker safety. A formal process for implementing PtD for MEP worker safety is badly needed because MEP work onsite and during operation and maintenance (O&M) can lead to injury and death. To address this knowledge gap, our research team aimed to create a formalized PtD process for MEP safety and developed case studies that detail how the process can be implemented in the field. The formalized process and case studies would then be used in an implementation guide created specifically for the industry. This project was completed through expert interviews, six case studies, and ongoing discussion and review by an Industry Advisory Council. Using these methods, the team identified factors for implementation success and developed a formalized PtD process specific to the MEP worker context. The process consists of five phases: (1) hazard identification, (2) risk assessment, (3) design review, (4) implementation, and (5) learning. We anticipate that this study will contribute to the field of PtD research through creating one of the first formalized PtD processes for MEP construction and O&M worker safety, and through a cross-case analysis of the six PtD cases that indicated not only the importance of stakeholder engagement and cross-disciplinary dialogue, but that effective PtD implementation can occur even outside of a collaborative project delivery context at any point during design and construction.
Keywords
Construction Safety; Health; Attitude; Prevention Through Design (ptd); Construction Worker Safety; Mechanical; Electrical; Plumbing (mep)
Gambatese, John A.; Pestana, Catarina; Lee, Hyun Woo. (2017). Alignment between Lean Principles and Practices and Worker Safety Behavior. Journal Of Construction Engineering And Management, 143(1).
View Publication
Abstract
Alignment and synergy between the areas of lean construction and safety management are expected because all near misses and injury incidents represent waste from the lean perspective. This paper describes a research study of lean and safety principles and practices with regards to worker behavior and safety practices. Specifically, the study aimed to investigate the extent of alignment between lean construction principles/practices and worker behaviors associated with construction safety. To conduct the study, the researchers used a multistep process involving a comprehensive literature review, document content analyses by an expert panel, and a survey of industry practitioners knowledgeable about lean construction. The findings support the perspective that many similarities exist between the application and impacts of lean and safety principles and practices. Lean practitioners surveyed believe that implementation of the last planner system as a lean practice is most beneficial to the following safety practices: management commitment, preproject planning, and pretask planning. The present study revealed that lean principles and practices can provide a valuable opportunity to further improve construction worker safety; however, the findings show that there is a difference between lean construction and safety management practices, revealing a gap with respect to worker behavior. Understanding and eliminating this gap is important for the industry to realize the full benefit that lean principles and practices can have on worker safety. To do so, the authors suggest expanding lean practices to further directly engage field workers and address worker behavior issues along with carefully communicating the lean message to construction personnel. (C) 2016 American Society of Civil Engineers.
Keywords
Construction Industry; Injuries; Lean Production; Occupational Safety; Planning; Lean Principles; Lean Construction; Safety Management Practices; Injury Incidents; Worker Behaviors; Construction Safety; Document Content Analysis; Management Commitment; Preproject Planning; Pretask Planning; Construction Worker Safety Behavior; Construction Accident Causality; Risk; Lean Design; Worker Behavior; Safety; Labor And Personnel Issues
Choi, Suji; Kim, Soyeon; Kwak, Mingi; Park, Jaewan; Park, Subin; Kwak, Dongjoon; Lee, Hyun Woo; Lee, Sangwon. (2022). Would You Trust Driverless Service? Formation Of Pedestrian’s Trust And Attitude Using Non-verbal Social Cues. Sensors (14248220), 22(7).
View Publication
Abstract
Despite the widespread application of Autonomous Vehicles (AV) to various services, there has been relatively little research carried out on pedestrian-AV interaction and trust within the context of service provided by AV. This study explores the communication design strategy promoting a pedestrian's trust and positive attitude to driverless services within the context of pedestrian-AV interaction using non-verbal social cues. An empirical study was conducted with an experimental VR environment to measure participants' intimacy, trust, and brand attitude toward AV. Further understanding of their social interaction experiences was explored through semi-structured interviews. As a result of the study, the interaction effect of social cues was found, and it was revealed that brand attitude was formed by the direct effects of intimacy and trust as well as the indirect effects of intimacy through trust's mediation. Furthermore, 'Conceptual Definition of Space' was identified to generate differences in the interplay among intimacy, trust, and brand attitude according to social cues. Quantitative and qualitative results were synthesized to discuss implications considering the service context. Practical implications were also addressed suggesting specific design strategies for utilizing the sociality of AV.
Keywords
Pedestrians; Nonverbal Cues; Consumer Attitudes; Social Attitudes; Social Interaction; Attitude (psychology); Autonomous Vehicles; Brand Attitude; Driverless Service; Intimacy; Pedestrian–av Interaction; Social Cues; Trust; Pedestrian-av Interaction; Conversational Agent; Brand Experience; Impact; Automation; Perception; Disclosure; Style; Gaze
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
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).
View Publication
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
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.
View Publication
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
Nnaji, Chukwuma; Lee, Hyun Woo; Karakhan, Ali; Gambatese, John. (2018). Developing a Decision-Making Framework to Select Safety Technologies for Highway Construction. Journal Of Construction Engineering And Management, 144(4).
View Publication
Abstract
Highway construction has consistently reported relatively high fatality rates largely because of the considerable exposure of workers to live traffic. To address this anomaly, traffic control planners are tasked with making decisions geared toward reducing hazardous situations caused by transiting vehicles and construction equipment. The growing application of technologies to enhance worker safety should be considered during the traffic control planning process. In certain cases, decisions such as choosing among technology options are made using experiential individual knowledge without the application of scientific and systematic decision-making methods. Use of experience-based decision making in this context is largely the result of sparse literature on scientific methods of selecting between alternatives in highway construction work zones. By applying the Choosing by Advantages (CBA) decision-making method, a process that achieves sound and effective decisions, the current study aims to fill the gap in practice by proposing a decision-making framework that could enhance the value-cost selection process of safety technologies in highway construction work zones. A situation that applied work zone intrusion alert technologies (WZIATs) was selected as a case study. Using a focus group session and case projects as an evaluation study process, the proposed framework based on the CBA decision-making process was applied to evaluate three WZIATs. Findings from the current study will benefit safety professionals and practitioners by providing a step-by-step approach to make sound decisions that can enhance the level of safety in highway construction work zones.
Keywords
Construction Equipment; Decision Making; Occupational Safety; Project Management; Road Building; Effective Decisions; Decision-making Framework; Value-cost Selection Process; Highway Construction Work Zones; Work Zone Intrusion Alert Technologies; Cba Decision-making Process; Sound Decisions; Traffic Control Planners; Worker Safety; Traffic Control Planning Process; Technology Options; Scientific Decision-making Methods; Systematic Decision-making Methods; Experience-based Decision Making; Advantages Decision-making Method; Safety Technologies; Knowledge; Signs
Nnaji, Chukwuma; Gambatese, John; Lee, Hyun Woo. (2018). Work Zone Intrusion: Technology to Reduce Injuries & Fatalities. Professional Safety, 63(4), 36 – 41.
View Publication
Abstract
WZIAT was first introduced to work zones in 1995 following a Strategic Highway Research Program (SHRP)-sponsored study (Agent & Hibbs, 1996). Since the SHRP program, several WZIATs have been developed, evaluated by departments of transportation (DOTs) and implemented in work zones on many highway projects. [...]the researchers investigated the potential usefulness of WZIATs on reported fatal work zone intrusion cases. [...]the researchers identified and evaluated work zone fatality cases captured in the NIOSH Fatality Assessment and Control Evaluation (FACE) program to determine whether WZIATs could have prevented the reported fatalities. [...]construction and maintenance workers are provided additional reaction time if an intrusion occurs before the activity zone.
Keywords
Research; Fatalities; Highway Construction; Injury Prevention; Traffic Accidents & Safety; Automobile Safety; Roads & Highways; Transportation Planning; Electronic Mail Systems; Researchers; Intrusion; General Contractors; Occupational Health; Vehicles; Studies; Workers; Employees; Construction Industry; Traffic Control; United States--us; Canada; Kansas; Oregon
Park, Kyungmo; Lee, Hyun Woo; Choi, Kunhee; Lee, Seung-hyun. (2019). Project Risk Factors Facing Construction Management Firms. International Journal Of Civil Engineering, 17(3), 305 – 321.
View Publication
Abstract
Very little is known about the project risk factors that affect construction management (CM) firms, which often struggle due to a lack of effective risk management practices. This study investigates the risk factors critical to project execution in CM firms and ranks them using the analytic hierarchy process (AHP) and failure mode and effects analysis (FMEA) methods. Interviews with executives at the top 15 Korean CM firms are carried out to identify major risk factors in the CM sector, and a survey is used to develop priority ranking. We find that payment delays and project delays are the two most critical risk factors affecting CM firms because of (1) lack of communication between headquarters and field offices, (2) shift of responsibility from headquarters to a field office, (3) absence of regular monitoring of project progress, and (4) ex-post management practices. The findings presented in this study should assist CM firms in establishing more robust risk management practices, thereby improving firms' profitability, project performance, and customer satisfaction.
Keywords
Analytic Hierarchy Process; Customer Satisfaction; Factor Analysis; Risk Assessment; Risk Management; Analytic Hierarchy Process (ahp); Construction Management; Construction Management Firms; Failure Mode And Effects Analysis; Korea; Management Practices; Risk Factors; Risk Management Practices; Industry