Kandil, Amr; El-Rayes, Khaled; El-Anwar, Omar. (2010). Optimization Research: Enhancing the Robustness of Large-Scale Multiobjective Optimization in Construction. Journal Of Construction Engineering And Management, 136(1), 17 – 25.
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Abstract
Many construction planning problems require optimizing multiple and conflicting project objectives such as minimizing construction time and cost while maximizing safety, quality, and sustainability. To enable the optimization of these construction problems, a number of research studies focused on developing multiobjective optimization algorithms (MOAs). The robustness of these algorithms needs further research to ensure an efficient and effective optimization of large-scale real-life construction problems. This paper presents a review of current research efforts in the field of construction multiobjective optimization and two case studies that illustrate methods for enhancing the robustness of MOAs. The first case study utilizes a multiobjective genetic algorithm (MOGA) and an analytical optimization algorithm to optimize the planning of postdisaster temporary housing projects. The second case study utilizes a MOGA and parallel computing to optimize the planning of construction resource utilization in large-scale infrastructure projects. The paper also presents practical recommendations based on the main findings of the analyzed case studies to enhance the robustness of multiobjective optimization in construction engineering and management.
Keywords
Optimizing Resource Utilization; Trade-off; Highway Construction; Genetic Algorithms; Cost; Model; Network; Design; Colony; Optimization Models; Parallel Processing; Resource Management; Housing; Multiple Objective Analysis; Linear Analysis; Algorithms
Bogus, Susan M.; Migliaccio, Giovanni C.; Jin, Ruoyu. (2013). Study of the Relationship between Procurement Duration and Project Performance in Design-Build Projects: Comparison between Water/Wastewater and Transportation Sectors. Journal Of Management In Engineering, 29(4), 382 – 391.
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Abstract
Previous studies on building, industrial, and transportation projects found that projects delivered using design-build tend to perform better than projects delivered with the traditional design-bid-build method. However, performance of design-build projects is affected by various factors, with procurement-related factors being among the most influential. Whereas other aspects of procurement have been largely investigated, the effect of procurement duration on project performance has been studied only for design-build transportation projects. In addition, few studies have focused specifically on the delivery of water/wastewater projects. This paper includes the results of a study on the relationship between procurement duration and performance of water/wastewater design-build projects. The study methodology was based on regression analysis of data from a sample of water/wastewater design-build projects. The results show that unlike the transportation sector, procurement duration has little effect on either schedule or cost performance in the water/wastewater sector. Likely reasons for this difference were then explored through a content analysis of procurement documents. (C) 2013 American Society of Civil Engineers.
Keywords
Design Engineering; Procurement; Project Management; Regression Analysis; Transportation; Waste Management; Procurement Documents; Schedule Performance; Cost Performance; Design-build Transportation Projects; Procurement-related Factors; Design-bid-build Method; Water-wastewater Sectors; Transportation Sectors; Project Performance; Procurement Duration; Design/build; Project Delivery; Water; Wastewater
El-Anwar, Omar; Aziz, Tamer Abdel. (2014). Integrated Urban-Construction Planning Framework for Slum Upgrading Projects. Journal Of Construction Engineering And Management, 140(4).
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Abstract
Slums are areas of population concentrations developed in the absence of physical planning and lack access to life essentials. Slums represent major national challenges in countries where they exist, especially developing countries. Various intervention strategies can be adopted to upgrade and/or replace slums, but are often faced with serious construction challenges, such as lack of access to sites and poor terrain conditions. Moreover, during the execution of slum upgrading projects, resident families can experience significant social and economic disruptions. The objective of this paper is present an integrated urban-construction planning framework for slum upgrading projects. This framework incorporates participatory upgrading and is designed to achieve three important objectives, including (1)maximizing the benefits of slum upgrading projects by identifying and accelerating the delivery of urgent projects; (2)providing more accurate and practical estimates of upgrading projects costs and timelines, which enables controlling and minimizing the total projects costs and durations; and (3)minimizing the social and economic disruptions for resident families during construction. An illustrative example is presented to demonstrate the potential of the proposed framework and its core multiobjective optimization process.
Keywords
Construction; Industrial Economics; Optimisation; Planning; Project Management; Social Sciences; Integrated Urban-construction Planning Framework; Slum Upgrading Projects; Physical Planning; Intervention Strategies; Construction Challenges; Economic Disruptions; Social Disruptions; Urgent Projects Delivery; Project Costs; Multiobjective Optimization Process; Logistics; Constructability; Optimization; Design; Build; Urban Areas; Slums Upgrading; Logistics Planning; Multi-objective Optimization; Integrated Design-build; Project Planning And Design
Huang, R.; Moudon, A. V.; Cook, A. J.; Drewnowski, A. (2015). The Spatial Clustering of Obesity: Does the Built Environment Matter? Journal Of Human Nutrition & Dietetics, 28(6), 604 – 612.
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Abstract
BackgroundObesity rates in the USA show distinct geographical patterns. The present study used spatial cluster detection methods and individual-level data to locate obesity clusters and to analyse them in relation to the neighbourhood built environment. MethodsThe 2008-2009 Seattle Obesity Study provided data on the self-reported height, weight, and sociodemographic characteristics of 1602 King County adults. Home addresses were geocoded. Clusters of high or low body mass index were identified using Anselin's Local Moran's I and a spatial scan statistic with regression models that searched for unmeasured neighbourhood-level factors from residuals, adjusting for measured individual-level covariates. Spatially continuous values of objectively measured features of the local neighbourhood built environment (SmartMaps) were constructed for seven variables obtained from tax rolls and commercial databases. ResultsBoth the Local Moran's I and a spatial scan statistic identified similar spatial concentrations of obesity. High and low obesity clusters were attenuated after adjusting for age, gender, race, education and income, and they disappeared once neighbourhood residential property values and residential density were included in the model. ConclusionsUsing individual-level data to detect obesity clusters with two cluster detection methods, the present study showed that the spatial concentration of obesity was wholly explained by neighbourhood composition and socioeconomic characteristics. These characteristics may serve to more precisely locate obesity prevention and intervention programmes.
Keywords
Real Property; Ecology; Age Distribution; Anthropometry; Black People; Cluster Analysis (statistics); Communities; Computer Software; Epidemiological Research; Geographic Information Systems; Hispanic Americans; Mathematics; Obesity; Population Geography; Probability Theory; Race; Regression Analysis; Research Funding; Restaurants; Statistical Sampling; Self-evaluation; Sex Distribution; Shopping; Surveys; Telephones; Transportation; White People; Socioeconomic Factors; Body Mass Index; Data Analysis Software; Medical Coding; Statistical Models; Descriptive Statistics; Odds Ratio; Economics; Washington (state); Built Environment; Local Moran's I; Spatial Scan Statistic; Body-mass Index; Physical-activity; United-states; Risk-factors; Neighborhood; Association; Density; Disease; Disparities; Prevalence
Hashemloo, Alireza; Inanici, Mehlika; Meek, Christopher. (2016). Glareshade: A Visual Comfort-Based Approach to Occupant-Centric Shading Systems. Journal Of Building Performance Simulation, 9(4), 351 – 365.
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Abstract
This paper presents a novel method for designing of an occupant-centric shading algorithm that utilizes visual comfort metric as the form-generating criteria. Based on the premise of previous studies that demonstrate glare as the most important factor for operating shading devices, GlareShade is introduced as a simulation-based shading methodology driven by occupant's visual comfort. GlareShade not only responds to changing outdoor conditions such as the movement of the sun and the variation of cloud cover, but it also accounts for building specific local conditions. GlareShade draws its strength and flexibility from an occupant-centric approach that is based on the visual field of view of each occupant as the occupant is performing common visual tasks in a given environment, and the developed shading system is linked to a distributed sensing network of multiple occupants. ShadeFan is demonstrated as a proof-of-concept dynamic shading system utilizing the GlareShade method.
Keywords
Control Strategies; Design Tool; Daylight; Patterns; Offices; Blinds; Model; Occupant-centric Shading System; Glare; Daylighting; Visual Comfort
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).
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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
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).
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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
Eisenberg-Guyot, Jerzy; Moudon, Anne V.; Hurvitz, Philip M.; Mooney, Stephen J.; Whitlock, Kathryn B.; Saelens, Brian E. (2019). Beyond the Bus Stop: Where Transit Users Walk. Journal Of Transport & Health, 14.
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Abstract
Objectives: Extending the health benefits of public-transit investment requires understanding how transit use affects pedestrian activity, including pedestrian activity not directly temporally or spatially related to transit use. In this study, we identified where transit users walked on transit days compared with non-transit days within and beyond 400 m and 800 m buffers surrounding their home and work addresses. Methods: We used data collected from 2008 to 2013 in King County, Washington, from 221 non-physically-disabled adult transit users, who were equipped with an accelerometer, global positioning system (GPS), and travel diary. We assigned walking activity to the following buffer locations: less than and at least 400 m or 800 m from home, work, or home/work (the home and work buffers comprised the latter buffer). We used Poisson generalized estimating equations to estimate differences in minutes per day of total walking and minutes per day of non-transit-related walking on transit days compared with non-transit days in each location. Results: We found that durations of total walking and non-transit-related walking were greater on transit days than on non-transit days in all locations studied. When considering the home neighborhood in isolation, most of the greater duration of walking occurred beyond the home neighborhood at both 400 m and 800 m; results were similar when considering the work neighborhood in isolation. When considering the neighborhoods jointly (i.e., by using the home/work buffer), at 400 m, most of the greater duration of walking occurred beyond the home/work neighborhood. However, at 800 m, most of the greater duration of walking occurred within the home/work neighborhood. Conclusions: Transit days were associated with greater durations of total walking and non-transit related walking within and beyond the home and work neighborhoods. Accordingly, research, design, and policy strategies focused on transit use and pedestrian activity should consider locations outside the home and work neighborhoods, in addition to locations within them.
Keywords
Physical-activity; Public-transit; Accelerometer Data; Combining Gps; United-states; Travel; Transportation; Health; Time; Neighborhood
Way, Thaisa. (2019). What is the Urban Landscape and What Role in Urban History? Journal Of Urban History, 45(3), 595 – 600.
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Keywords
Urban; Landscapes; Modernism; Preservation; Architecture; Cities
Mooney, Stephen J.; Bobb, Jennifer F.; Hurvitz, Philip M.; Anau, Jane; Theis, Mary Kay; Drewnowski, Adam; Aggarwal, Anju; Gupta, Shilpi; Rosenberg, Dori E.; Cook, Andrea J.; Shi, Xiao; Lozano, Paula; Moudon, Anne Vernez; Arterburn, David. (2020). Impact of Built Environments on Body Weight (The Moving to Health Study): Protocol for a Retrospective Longitudinal Observational Study. Jmir Research Protocols, 9(5).
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Abstract
Background: Studies assessing the impact of built environments on body weight are often limited by modest power to detect residential effects that are small for individuals but may nonetheless comprise large attributable risks. Objective: We used data extracted from electronic health records to construct a large retrospective cohort of patients. This cohort will be used to explore both the impact of moving between environments and the long-term impact of changing neighborhood environments. Methods: We identified members with at least 12 months of Kaiser Permanente Washington (KPWA) membership and at least one weight measurement in their records during a period between January 2005 and April 2017 in which they lived in King County, Washington. Information on member demographics, address history, diagnoses, and clinical visits data (including weight) was extracted. This paper describes the characteristics of the adult (aged 18-89 years) cohort constructed from these data. Results: We identified 229,755 adults representing nearly 1.2 million person-years of follow-up. The mean age at baseline was 45 years, and 58.0% (133,326/229,755) were female. Nearly one-fourth of people (55,150/229,755) moved within King County at least once during the follow-up, representing 84,698 total moves. Members tended to move to new neighborhoods matching their origin neighborhoods on residential density and property values. Conclusions: Data were available in the KPWA database to construct a very large cohort based in King County, Washington. Future analyses will directly examine associations between neighborhood conditions and longitudinal changes in body weight and diabetes as well as other health conditions.
Keywords
Residential Location Choice; Physical-activity; Risk-factors; Food Desert; Neighborhood; Obesity; Association; Outcomes; Bmi; Accelerometer; Electronic Health Records; Built Environment; Washington; Geography; Longitudinal Studies