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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).

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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

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.

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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

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.

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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

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

Human-Centric Lighting Performance of Shading Panels in Architecture: A Benchmarking Study with Lab Scale Physical Models Under Real Skies

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

A Framework for Estimating Commute Accessibility and Adoption of Ridehailing Services Under Functional Improvements from Vehicle Automation

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

Threats to Municipal Information Systems Posed by Aging Infrastructure

Armbruster, Ginger; Endicott-Popovsky, Barbara; Whittington, Jan. (2013). Threats to Municipal Information Systems Posed by Aging Infrastructure. International Journal Of Critical Infrastructure Protection, 6(3-4), 123 – 131.

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Abstract

State and local governments across the United States are leveraging the Internet and associated technologies to dramatically change the way they offer public services. While they are motivated to capture efficiencies, the public entities increasingly rely on information systems that are dependent on energy and related civil structures. This reliance is incongruous with the widespread awareness of aging infrastructure - decaying for lack of investment - in cities across the United States. Important questions that come up in this environment of persistent expansion of the use of digital assets are the following: What threat does aging infrastructure pose to governmental reliance on computing infrastructures? How are local governments responding to this threat? Are the solutions posed appropriate to the problem, or do they pose new and different threats? This paper uses a case involving the disruption of a local government data center due to the failure of an electrical bus to illustrate how the threats of aging infrastructure grow, quietly and steadily, into emergencies, on par with the catastrophic events encountered in the context of critical infrastructure protection. The decisions precipitating the disruption are routine, borne of circumstances shared by agencies that are pressed to maintain services with scarce resources. Patterns of capital investment and management explain the emergence of crises in routine operations. If, as in the case described in this paper, deferred maintenance motivates public agents to explore private cloud services, then governments may solve several problems, but may also be exposed to new risks as they enter into arrangements from which they are unable to exit. (C) 2013 Elsevier B.V. All rights reserved.

Keywords

Aging Infrastructure; Municipal Data Center; Capital Improvement; Interdependence

BIM Curriculum Design in Architecture, Engineering, and Construction Education: A Systematic Review

Abdirad, Hamid; Dossick, Carrie S. (2016). BIM Curriculum Design in Architecture, Engineering, and Construction Education: A Systematic Review. Journal Of Information Technology In Construction, 21, 250 – 271.

Abstract

In the past several years, Building Information Modeling (BIM) adoption has grown significantly in the architecture, engineering, and construction (AEC) industry. In response to this trend, the industry and academia realized that BIM education in university curricula is an important requirement for satisfying educational demands of the industry, and a notable body of research has reported strategies AEC programs implemented to incorporate BIM in their curricula. However, no study has comprehensively reviewed and synthesized the research on sfrategies adopted by educators. To bridge this gap in the literature, this paper presents a systematic review of research on BIM curriculum design in AEC education. The authors report on the trends of research on BIM curriculum design (e.g. methods, timelines, and contexts) as well as a synthesis of implemented pedagogical strategies with detailed discussions on their implications and effectiveness across different studies and contexts. These strategies address a variety of important pedagogical issues such as enrolment of students, optional or required BIM use, important competencies and skills, tutoring methods, industry engagement, designing assignments, and assessment methods and criteria. This synthesis shows that designing pedagogical sfrategies for BIM education is complex and challenging, and AEC programs need to make trade-offs between advantages and disadvantages associated with these strategies. The results also highlight the need for more diverse research designs and settings to bridge the gaps identified in BIM curriculum research to date. Finally, the authors present a literature-based framework of BIM curriculum design sfrategies as well as a set of recommendations that can be used BIM educators and researchers as a guide for designing or assessing their BIM curricula in future research.

Keywords

Bridges; Curricula; Economic And Social Effects; Education; Information Theory; Personnel Training; Reviews; Students; Architecture; Engineering; And Constructions; Building Information Model; Bim; Curriculum Designs; Pedagogical Issues; Pedagogical Strategies; Research Designs; Systematic Review; University Curricula; Industry; Management; Building Information Modeling; Training; Curriculum; Review

Exploring the Influence of System Quality, Information Quality, and External Service on BIM User Satisfaction

Song, Jiule; Migliaccio, Giovanni C.; Wang, Guangbin; Lu, Hao. (2017). Exploring the Influence of System Quality, Information Quality, and External Service on BIM User Satisfaction. Journal Of Management In Engineering, 33(6).

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Abstract

Over the past decade, architecture, engineering and construction (AEC) companies around the world implemented building information modeling (BIM) to enhance their firms' competitiveness and readjust their business processes. Although substantial efforts have been made to implement BIM, previous research highlighted that implementation of BIM tools has not always resulted in satisfaction by users. Grounded in the literature on information systems and enterprise resource planning user satisfaction, this study tries to evaluate the success of BIM in terms of user satisfaction while controlling for the mediating effect of top-management support. The effects of four factors (i.e., system quality, information quality, external service, and top-management support) on BIM user satisfaction in AEC industries were examined through a survey of BIM users from China. Survey responses were analyzed with the partial least-squares method. The major contribution of this work lies in the findings that information quality, external service, and top-management support have a significant influence on BIM user satisfaction, and system quality did not have a significant influence on BIM user satisfaction. Moreover, top-management support acts as a mediating factor between external service and BIM user satisfaction. (C) 2017 American Society of Civil Engineers.

Keywords

Computing Satisfaction; Perceived Usefulness; Erp Systems; Success; Model; Performance; Technology; Acceptance; Tool; Determinants; Bim User Satisfaction; System Quality; Information Quality; External Services; Top-management Support