Choi, Kunhee; Bae, Junseo; Yin, Yangtian; Lee, Hyun Woo. (2021). Act(2): Time Cost Tradeoffs from Alternative Contracting Methods. Journal Of Management In Engineering, 37(1).
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Abstract
Incentive/disincentive (I/D) and cost-plus-time (A+B) are two of the most widely used alternative contracting methods (ACMs) for accelerating the construction of highway infrastructure improvement projects. However, little is known about the effects of trade-offs in terms of project schedule and cost performance. This study addresses this problem by creating and testing a stochastic decision support model called accelerated alternative contracting cost-time trade-off (ACT(2)). This model was developed by a second-order polynomial regression analysis and validated by the predicted error sum of square statistic and paired comparison tests. The results of a descriptive trend analysis based on a rich set of high-confidence project data show that I/D is effective at reducing project duration but results in higher cost compared to pure A+B and conventional methods. This cost-time trade-off effect was confirmed by the ACT(2) model, which determines the level of cost-time trade-off for different ACMs. This study will help state transportation agencies promote more effective application of ACMs by providing data-driven performance benchmarking results when evaluating competing acceleration strategies and techniques. (C) 2020 American Society of Civil Engineers.
Keywords
Highway; Construction; Model; Alternative Contracting Methods; Cost-plus-time; A Plus B; Incentive; Infrastructure Trend; Time-cost Trade-off
Zuidema, Christopher; Austin, Elena; Cohen, Martin A.; Kasner, Edward; Liu, Lilian; Isaksen, Tania Busch; Lin, Ken-Yu; Spector, June; Seto, Edmund. (2022). Potential Impacts Of Washington State’s Wildfire Worker Protection Rule On Construction Workers. Annals Of Work Exposures & Health, 66(4), 419 – 432.
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Abstract
Driven by climate change, wildfires are increasing in frequency, duration, and intensity across the Western United States. Outdoor workers are being exposed to increasing wildfire-related particulate matter and smoke. Recognizing this emerging risk, Washington adopted an emergency rule and is presently engaged in creating a permanent rule to protect outdoor workers from wildfire smoke exposure. While there are growing bodies of literature on the exposure to and health effects of wildfire smoke in the general public and wildland firefighters, there is a gap in knowledge about wildfire smoke exposure among outdoor workers generally and construction workers specifically-a large category of outdoor workers in Washington totaling 200,000 people. Several data sources were linked in this study-including state-collected employment data and national ambient air quality data-to gain insight into the risk of PM2.5 exposure among construction workers and evaluate the impacts of different air quality thresholds that would have triggered a new Washington emergency wildfire smoke rule aimed at protecting workers from high PM2.5 exposure. Results indicate the number of poor air quality days has increased in August and September in recent years. Over the last decade, these months with the greatest potential for particulate matter exposure coincided with an annual peak in construction employment that was typically 9.4-42.7% larger across Washington counties (one county was 75.8%). Lastly, the 'encouraged' threshold of the Washington emergency rule (20.5 mu g m(-3)) would have resulted in 5.5 times more days subject to the wildfire rule on average across all Washington counties compared to its 'required' threshold (55.5 mu g m(-3)), and in 2020, the rule could have created demand for 1.35 million N-95 filtering facepiece respirators among construction workers. These results have important implications for both employers and policy makers as rules are developed. The potential policy implications of wildfire smoke exposure, exposure control strategies, and data gaps that would improve understanding of construction worker exposure to wildfire smoke are also discussed.
Keywords
Particulate Matter; Industrial Safety; Occupational Exposure; Rules; Smoke; Construction Industry; Employment; Occupational Hazards; Descriptive Statistics; Industrial Hygiene; Wildfires; N95 Respirators; Washington (state); Forest Fires; Pm 2.5; Respirator; Wildfire Smoke Protection Rule; Wildland Fire; Pm2 5; Health Impacts; Climate-change; Forest-fire; Exposure; Firefighters; Infiltration
El-Anwar, Omar; El-Rayes, Khaled; Elnashai, Amr. (2010). Maximizing Temporary Housing Safety after Natural Disasters. Journal Of Infrastructure Systems, 16(2), 138 – 148.
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Abstract
In the aftermath of large-scale natural disasters, emergency management organizations are expected to provide safe temporary housing for a large number of displaced families and to ensure that these housing arrangements are not located in hazardous areas. Potential postdisaster hazards can take many forms such as earthquake aftershocks, landslides, postearthquake soil liquefaction, flooding, hazardous material releases, etc. This paper presents the development of a multiobjective optimization methodology to support decision-makers in emergency management organizations in optimizing postdisaster temporary housing arrangements. The developed methodology incorporates (1) a safety model to measure and quantify temporary housing safety in the presence of multiple potential postdisaster hazards; (2) a cost model to minimize total public expenditures on temporary housing; and (3) a multiobjective optimization model to simultaneously maximize temporary housing safety and minimize public expenditures on temporary housing. An application to a large region is presented to illustrate the use of the models and demonstrate their capabilities in optimizing postdisaster temporary housing arrangements.
Keywords
Earthquake; Landslides; Optimization; Temporary Housing; Postdisaster Hazards; Housing Safety; Postdisaster Recovery
Streatfield, David C. (2012). The San Francisco Peninsula’s Great Estates: Part II. Eden, 15(2), 1 – 17.
Abstract
This article discusses the landscaping of American country estates built in late 19th century in San Francisco Peninsula. These estates are mentioned to have been influenced by the growing popularity of gardening in Europe. Andrew Jackson, America's first landscape architecture practitioner, is cited for promoting garden styles derived from English precedents. Some of the noteworthy estates built during the first three decades of 20th century are also described like New Place and Green Gables.
Keywords
Landscape Gardening; Country Homes; Gardening; Landscape Architecture; Europe; Jackson, Andrew
Dossick, Carrie Sturts(1). (2014). Messy Work in Virtual Worlds: Exploring Discovery and Synthesis in Virtual Teams. Lecture Notes In Computer Science (including Subseries Lecture Notes In Artificial Intelligence And Lecture Notes In Bioinformatics), 8683, 134 – 142.
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Abstract
The challenges of engineering team collaboration—establishing trust, fostering productive informal communication, cultivating knowledge exchange—are often exacerbated in virtual teams by geographical separation as well as team members’ cultural and linguistic differences. Researchers have observed that powerful collaboration in collocated teams is supported by shared visualizations with which the team engages in informal, flexible and active ways. In studying virtual team interactions in a virtual world known as the CyberGRID, we see that just as with AEC collocated teams, shared visualizations were instrumental for the teams as they define, understand, and generate knowledge when working on interrelated tasks. Emerging from this analysis is an empirically supported theory that while avatar-model interaction supports mutual discovery, more messy interactions of brainstorming, knowledge exchange and synthesis requires flexible, active, and informal shared visualizations. © Springer International Publishing Switzerland 2014.
Keywords
Communication; Flow Visualization; Information Technology; Knowledge Management; Visualization; Building Information Model; Bim; Collaboration; Geographical Separation; Global Virtual Teams; Informal Communication; Linguistic Differences; Virtual Team Interactions; Virtual Worlds
D’Incognito, Maria; Costantino, Nicola; Migliaccio, Giovanni C. (2015). Actors and Barriers to the Adoption of LCC And LCA Techniques in the Built Environment. Built Environment Project And Asset Management, 5(2), 202 – 216.
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Abstract
Purpose - The purpose of this paper is to evaluate the existing barriers to the slow adoption of Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) in construction, and the main responsible actors. Design/methodology/approach - The research design is based on a two-phase approach. First, the existing literature was studied through a multiple-step content analysis (CA) approach, which combined unsupervised concept mapping with computer aided CA. Using a relational CA approach, statistical-based analysis tools were initially used to identify the relationships between actors and barriers. Later, a Delphi study was administered to a panel of experts, to triangulate, validate, and refine the initial results. Findings - The study revealed that organizational culture is the most relevant barrier, and that clients and professionals are the actors that predominantly influence the adoption of LCC and LCA in projects. Technical and financial barriers, such as the lack and quality of input data and the high costs of implementation are also deemed relevant. Research limitations/implications - The CA was performed by a single rater on a sample that included 50 papers in English language. Future research may focus on enlarging the sample, extending it to other languages, and linking the source (or the expert) to their professional context to evaluate geographical differences in barriers. Originality/value - The adopted approach gives new insights on the relationships behind the rejection of LCA and LCC suggesting that solutions at the organizational level may be more effective than technical ones.
Keywords
Construction; Innovation; Content Analysis; Sustainability; Organizational Culture; Lca; Lcc; Life Cycle Management; Innovations; Life Cycle Costs; Experts; Software; Corporate Culture; Concept Mapping; Urban Environments; Computer Aided Mapping; Life Cycles; Life Cycle Engineering; Decision Making; Organizational Aspects; Supply Chains; Research Design; Professionals; Construction Industry; Construction Costs; Life Cycle Analysis; Urban Areas; English Language; Barriers; Regulation Of Financial Institutions; Life Cycle Assessment
Drewnowski, Adam; Aggarwal, Anju; Tang, Wesley; Hurvitz, Philip M.; Scully, Jason; Stewart, Orion; Moudon, Anne Vernez. (2016). Obesity, Diet Quality, Physical Activity, and the Built Environment: The Need for Behavioral Pathways. BMC Public Health, 16.
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Abstract
Background: The built environment ( BE) is said to influence local obesity rates. Few studies have explored causal pathways between home-neighborhood BE variables and health outcomes such as obesity. Such pathways are likely to involve both physical activity and diet. Methods: The Seattle Obesity Study ( SOS II) was a longitudinal cohort of 440 adult residents of King Co, WA. Home addresses were geocoded. Home-neighborhood BE measures were framed as counts and densities of food sources and physical activity locations. Tax parcel property values were obtained from County tax assessor. Healthy Eating Index ( HEI 2010) scores were constructed using data from food frequency questionnaires. Physical activity ( PA) was obtained by self-report. Weights and heights were measured at baseline and following 12 months' exposure. Multivariable regressions examined the associations among BE measures at baseline, health behaviors ( HEI-2010 and physical activity) at baseline, and health outcome both cross-sectionally and longitudinally. Results: None of the conventional neighborhood BE metrics were associated either with diet quality, or with meeting PA guidelines. Only higher property values did predict better diets and more physical activity. Better diets and more physical activity were associated with lower obesity prevalence at baseline and 12 mo, but did not predict weight change. Conclusion: Any links between the BE and health outcomes critically depend on establishing appropriate behavioral pathways. In this study, home-centric BE measures, were not related to physical activity or to diet. Further studies will need to consider a broader range of BE attributes that may be related to diets and health.
Keywords
Body-mass Index; Local Food Environment; Residential Property-values; Supermarket Accessibility; Park Proximity; Neighborhood Walkability; Vegetable Consumption; Atherosclerosis Risk; Restaurant Food; Associations; Built Environment; Physical Activity; Obesity; Diet Quality
Anderson, Anne; Dossick, Carrie Sturts; Iorio, Josh; Taylor, John E. (2017). The Impact of Avatars, Social Norms and Copresence on the Collaboration Effectiveness of AEC Virtual Teams. Journal Of Information Technology In Construction, 22, 287 – 304.
Abstract
A growing number of architecture, engineering, and construction (AEC) firms are outsourcing complex design and construction work to international vendors. Due to the significant geographic distances that can separate project team members in global design networks, much of this work is executed in virtual teams, defined as teams composed of geographically separated members who collaborate to accomplish organizational tasks mediated by technology. The challenges of working in geographically distributed networks have prompted the development of alternative, virtual workspaces. Questions remain on how these virtual workspaces support or hinder collaborative work. People are social beings that rely on body language and other non-verbal cues to communicate. What happens to team formation and collaborative effectiveness when non-verbal cues are mediated through avatar actions? In this paper, qualitative ethnographic data collected over four years from studies conducted in a 3D virtual world are used to examine collaboration effectiveness of global virtual engineering project teams. We found that avatar movement and position was effective at communicating nonverbal information, even when done so unintentionally. Avatar actions that map to established social norms in the physical world results in more efficient communication. Collaboration was also enhanced when gesture bubbles were used for backchannel communication and when text chat was used to avoid interrupting voice communication. We found collaboration was hindered when the learning curve was too steep for participants to adapt to tool use or avatar actions in the environment. These findings have important implications for the future of collaboration in virtual environments, particularly in the AEC industry where 3D models can be imported into the virtual environment and explored synchronously by a project team.
Keywords
Architectural Design; Human Resource Management; International Trade; Bim Coordination; Collaboration Technology; Distributed Teams; Social Norm; Virtual Worlds; Communication; Design; Technology; Dimensions; Teamwork; Behavior; Collaboration Technologies; Social Norms
Dannenberg, Andrew L.; Burpee, Heather. (2018). Architecture for Health Is Not Just for Healthcare Architects. Health Environments Research & Design Journal (herd) (sage Publications, Ltd.), 11(2), 8 – 12.
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Keywords
Building Design & Construction; Public Health; Quality Of Life; Built Environment; Public Spaces
Drewnowski, A.; Arterburn, D.; Zane, J.; Aggarwal, A.; Gupta, S.; Hurvitz, P. M.; Moudon, A., V; Bobb, J.; Cook, A.; Lozano, P.; Rosenberg, D. (2019). The Moving to Health (M2H) Approach to Natural Experiment Research: A Paradigm Shift for Studies on Built Environment and Health. Ssm-population Health, 7.
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Abstract
Improving the built environment (BE) is viewed as one strategy to improve community diets and health. The present goal is to review the literature on the effects of BE on health, highlight its limitations, and explore the growing use of natural experiments in BE research, such as the advent of new supermarkets, revitalized parks, or new transportation systems. Based on recent studies on movers, a paradigm shift in built-environment health research may be imminent. Following the classic Moving to Opportunity study in the US, the present Moving to Health (M2H) strategy takes advantage of the fact that changing residential location can entail overnight changes in multiple BE variables. The necessary conditions for applying the M2H strategy to Geographic Information Systems (GIS) databases and to large longitudinal cohorts are outlined below. Also outlined are significant limitations of this approach, including the use of electronic medical records in lieu of survey data. The key research question is whether documented changes in BE exposure can be linked to changes in health outcomes in a causal manner. The use of geo-localized clinical information from regional health care systems should permit new insights into the social and environmental determinants of health.
Keywords
Body-mass Index; Neighborhood Food Environment; Residential Property-values; Cardiometabolic Risk-factors; New-york-city; Physical-activity; Obesity Rates; King County; Weight-gain; Land-use; Built Environment (be); Geographic Information Systems (gis); Electronic Medical Records; Natural Experiments; Obesity; Diabetes; Residential Mobility