Inanici, Mehlika; Hashemloo, Alireza. (2017). An Investigation of the Daylighting Simulation Techniques and Sky Modeling Practices for Occupant Centric Evaluations. Building And Environment, 113, 220 – 231.
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Abstract
Occupant centric performance approaches in daylighting studies promote design decisions that support human visual comfort, productivity, and visual preferences, along with more conventional energy efficiency criteria. Simulating per-pixel luminance values and luminance distribution patterns for the entire scene allows us to analyze the occupant centric metrics and performance criteria. However, there are a number of different sky models, complex fenestration models, and simulation techniques that produce either conventional point in time images or annual luminance maps. This paper discusses the similarities and differences between different techniques; and a comparison analyses provides insight about their impact on occupant centric lighting measures. The comparisons for sky modeling include the conventional CIE skies (Clear, Intermediate, and Overcast), measurement based CIE models, Perez all-weather skies, and high dynamic range image based skies. The comparison of simulation techniques include point in time simulations, image based lighting simulations, and annual luminance simulations (threephase and five-phase methods). Results demonstrate that measurement based sky models match real world conditions with reasonable proximity, and generic CIE skies consistently underestimate the indoor lighting conditions. Annual simulation methods provide a large database of temporal luminance variations, where individual instances are comparable to point in time simulations. Long term luminance simulations provide opportunities to evaluate the percentage of the year that a given luminance based criteria is met or violated. (C)2016 Elsevier Ltd. All rights reserved.
Keywords
Complex Fenestration Systems; Scattering Distribution-functions; Discomfort Glare; Visual Comfort; Daylit Spaces; Validation; Radiance; Performance; Offices; Design; Sky Models; Daylight Simulations; Point In Time Simulations; Image Based Lighting; Annual Lighting Simulations; Annual Luminance Maps
Lee, Wonil; Migliaccio, Giovanni C. (2018). Temporal Effect of Construction Workforce Physical Strain on Diminishing Marginal Productivity at the Task Level. Journal Of Construction Engineering And Management, 144(9).
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Abstract
Physiological status and environmental stressors are known to influence workforce performance at the individual worker level. A previous study, which conducted a cross-sectional comparison in repetitive material-handling construction activities, suggested that a U-shaped relationship existed between physical strain and productivity at the group level. This research revisits those findings to further investigate the U-curve relationship between physical strain and productivity at the group level and validate the concept of diminishing marginal productivity. Heart rates were measured as an indicator of subjects' physical strain, whereas task productivity was estimated by work sampling. Eighty person-hour data were converted into panel data sets by dividing each subject's 4-h experimental data into 5-min intervals. These data sets were subsequently used to evaluate the effects of time on physical strain and productivity with 5-min lags. The study found a U-curve relationship between physical strain and task-level productivity at the group level while controlling for individual characteristics. The U-shape relationship was constant in the low-performance and high-performance groups, although the degrees of the polynomials differed. Productive workers will remain more productive than low-productive workers with increased physical strain.
Keywords
Construction Industry; Industrial Psychology; Labour Resources; Occupational Health; Polynomials; Productivity; Physiological Status; Environmental Stressors; U-shaped Relationship; Productive Workers; Polynomials Degree; Diminishing Marginal Productivity; Construction Workforce Physical Strain; Labor Productivity; Scientific Management; Shift Work; Performance; Model; Taylorism; Burnout; Design; Impact; Safety; Construction Productivity; Labor And Personal Issue; Work Physiology; Physical Strain
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
Adhikari, Pramodit; Mahmoud, Hussam; Xie, Aiwen; Simonen, Kathrina; Ellingwood, Bruce. (2020). Life-Cycle Cost and Carbon Footprint Analysis for Light-framed Residential Buildings Subjected to Tornado Hazard. Journal Of Building Engineering, 32.
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Abstract
Light-frame wood building construction dominates the single-family residential home market in the United States. Such buildings are susceptible to damage from extreme winds due to hurricanes in coastal areas and tornados in the Midwest. The consequences of extreme winds on the built environment and on social and economic institutions within the community can be severe and are likely to increase in the coming decades as a result of increases in urbanization and economic development and the potential impacts of changing climate in hazard prone areas. Current building practices provide minimum standards for occupant safety and health, including structural integrity, water and sanitation, lighting, ventilation, means of egress and fire protection. However, they generally do not consider building resilience, which includes robustness and an ability to recover following extreme natural hazard events. Nor do they address sustainability, the notion that building design, construction and rehabilitation should not adversely impact the environment. In this paper, we establish a generalized cost and carbon footprint life-cycle analysis methodology for examining the benefits of different building practices for residential light-frame wood construction subjected to tornado hazards. A multiobjective approach is used to reveal tradeoffs between resilient and sustainable practices for typical residential construction. We show that when the life cycle of a typical residence is considered, a balance between resilience, sustainability and cost might be achieved in design and rehabilitation of residential building construction for tornado hazards.
Keywords
Performance; Risk; Fragility; Residential Buildings; Life-cycle Analysis; Resilience; Optimal Decisions; Sustainable Construction; Tornadoes
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
Shtrepi, Louena; Echenagucia, Tomás Méndez; Badino, Elena; Astolfi, Arianna. (2021). A Performance-based Optimization Approach For Diffusive Surface Topology Design. Building Acoustics, 28(3), 231 – 247.
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Abstract
Different numerical techniques have been used in the last decades for the acoustic characterization and performance optimization of sound diffusive surfaces. However, these methods require very long calculation times and do not provide a rapid feedback. As a result, these methods can hardly be applied by designers at early stages of the design process, when successive design iterations are necessary from an aesthetic point of view. A suitable alternative could be the use of parametric modeling in combination with performance investigations during the design process of sound diffusive surfaces. To this aim, this study presents a design process for diffusive surfaces topology optimization based on the combination of parametric models and geometrical acoustic simulations. It aims to provide architects and designers with rapid visual feedback on acoustic performances at a preliminary stage of the design process. The method has been tested on different case studies, which have been modelled based on geometric guidelines for diffusive surface optimization. The sensitivity of the method showed that it could be a very useful tool for comparisons among surface design alternatives. Finally, the advantages and limitations of the integrated optimization in comparison with conventional optimizations are discussed.
Keywords
Acoustic Performance; Room Acoustics; Scattering; Coefficients; Accuracy; Field; Simulations; Diffusion; Surface Optimization; Performance-based Design
Lucko, Gunnar; Rojas, Eddy M. (2010). Research Validation: Challenges and Opportunities in the Construction Domain. Journal Of Construction Engineering And Management, 136(1), 127 – 135.
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Abstract
Validation of the research methodology and its results is a fundamental element of the process of scholarly endeavor. Approaches used for construction engineering and management research have included experiments, surveys and observational studies, modeling and simulation, theory building, case studies, and various subtypes thereof. Some studies use more than one approach. A particular contribution of this paper is that it reviews different types of validation using examples of studies, analyzes the specific challenges that were found to be significant, and presents how they were successfully overcome in each case. Another contribution is that it describes new opportunities for research validation that are emerging at the horizon as well as ongoing collaborative efforts to enhance the access of construction researchers to validation tools. This paper increases the awareness of the paramount role that validation techniques play in scholarly work by providing readers with recommendations to properly validate their own research efforts.
Keywords
Labor Productivity; Regression-models; Delivery-systems; Performance; Cost; Methodology; Management; Framework; Control Methods; Delphi Method; Models; Research Needs; Sampling Design; Statistical Analysis; Surveys; Validation; Verification
Cheng, Tao; Migliaccio, Giovanni C.; Teizer, Jochen; Gatti, Umberto C. (2013). Data Fusion of Real-Time Location Sensing and Physiological Status Monitoring for Ergonomics Analysis of Construction Workers. Journal Of Computing In Civil Engineering, 27(3), 320 – 335.
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Abstract
Previous research and applications in construction resource optimization have focused on tracking the location of material and equipment. There is a lack of studies on remote monitoring for improving safety and health of the construction workforce. This paper presents a new approach for monitoring ergonomically safe and unsafe behavior of construction workers. The study relies on a methodology that utilizes fusion of data from continuous remote monitoring of construction workers' location and physiological status. To monitor construction workers activities, the authors deployed nonintrusive real-time worker location sensing (RTLS) and physiological status monitoring (PSM) technology. This paper presents the background and need for a data fusion approach, the framework, the test bed environment, and results to some case studies that were used to automatically identify unhealthy work behavior. Results of this study suggest a new approach for automating remote monitoring of construction workers safety performance by fusing data on their location and physical strain. DOI: 10.1061/(ASCE)CP.1943-5487.0000222. (C) 2013 American Society of Civil Engineers.
Keywords
Civil Engineering Computing; Construction Industry; Ergonomics; Occupational Health; Occupational Safety; Personnel; Sensor Fusion; Psm Technology; Rtls Technology; Construction Workforce Health; Construction Workforce Safety; Equipment Location; Material Location; Construction Resource Optimization; Construction Worker; Ergonomics Analysis; Physiological Status Monitoring; Realtime Location Sensing; Data Fusion; Exposure; Tracking; Demands; Sensors; System; Construction Worker Behavior; Remote Location Sensing; Work Sampling; Workforce Safety And Health
Gatti, Umberto C.; Schneider, Suzanne; Migliaccio, Giovanni C. (2014). Physiological Condition Monitoring of Construction Workers. Automation In Construction, 44, 227 – 233.
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Abstract
Monitoring of workers' physiological conditions can potentially enhance construction workforce productivity, safety, and well-being. Recently, Physiological Status Monitors (PSMs) were validated as an accurate technology to assess physiological conditions during typical sport science and medicine testing procedures (e.g., treadmill and cycle ergometer protocols). However, sport science and medicine testing procedures cannot simulate routine construction worker movements in a comprehensive manner. Thus, this paper investigated the validity of two PSMs by comparing their measurements with gold standard laboratory instruments' measurements at rest and during dynamic activities resembling construction workforce's routine activities. Two physiological parameters such as heart rate and breathing rate were considered. Ten apparently healthy subjects participated in the study. One of the PSMs proved to be a viable technology in assessing construction workers' heart rate (correlation coefficient >= 0.74; percentage of differences within +/- 11 bpm >= 84.8%). (C) 2014 Elsevier B.V. All rights reserved,
Keywords
Construction Workers; Labor Supply; Labor Productivity; Well-being; Health Status Indicators; Heart Rate Monitoring; Physiology; Construction Management; Construction Worker; Ergonomics; Occupational Health And Safety; Physiological Status Monitoring Technology; Productivity; Work Physiological Demand; Work Physiology; Construction Industry; Monitoring; Occupational Safety; Medicine Testing; Sport Science; Psm; Physiological Status Monitors; Safety; Construction Workforce Productivity; Workers Monitoring; Physiological Condition Monitoring; Heart-rate Monitors; R-r Intervals; Statistical-methods; Respiratory Rate; Physical Load; Polar S810; Strain; Validity; Reliability; Validation
Kim, Sang-chul; Kim, Yong-woo; Park, Kun Soo; Yoo, Choong-yuel. (2015). Impact of Measuring Operational-Level Planning Reliability on Management-Level Project Performance. Journal Of Management In Engineering, 31(5).
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Abstract
The earned value management system (EVMS) and the last planner system (LPS) have been widely used as effective performance measurement tools for construction managers and production units at construction projects. While the EVMS measures project-level costs and scheduling performances, the LPS measures the percent plan complete (PPC), which indicates the level of planning reliability. This paper investigates the relationship between planning reliability at the operational level and project performance at the management level (i.e., the success or failure of a project). Analyzing the empirical data of 23 residential projects of a large construction company, the authors find that, while the production plan in the weekly schedule is correlated rigidly with the daily plan in successful projects, such a rigid correlation is not observed in unsuccessful projects. To understand this finding, the authors further conducted interviews with project stakeholders. Taken together, this study suggests that an emphasis on LPS indices causes subcontractors to engage in myopic behaviors such as modifying operational-level indices. Consequently, management-level production plan rigidity is at risk. The findings in this paper offer valuable insights and help project stakeholders understand the attributes of operational-level and management-level indices and their relationships. (C) 2014 American Society of Civil Engineers.
Keywords
Construction Industry; Costing; Production Planning; Project Management; Reliability; Scheduling; Subcontracting; Construction Projects; Production Units; Myopic Behaviors; Project Stakeholders; Subcontractors; Production Plan; Percent Plan Completion; Scheduling Performances; Project-level Costs; Performance Measurement Tools; Construction Managers; Last Planner System; Earned Value Management System; Management-level Project Performance; Evms; Operational-level Planning Reliability; Balanced Scorecard; Lean Construction; Contractors; Indexes; Design; Model; Earned Value; Lean; Construction; Schedule Performance Index; Cost Performance Index; Percent-plan-completion; Empirical Analysis