Shang, Luming; Migliaccio, Giovanni C. (2020). Demystifying Progressive Design Build: Implementation Issues and Lessons Learned through Case Study Analysis. Organization Technology And Management In Construction, 12(1), 2095 – 2108.
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Abstract
The design-build (DB) project delivery method has been used for several decades in the US construction market. DB contracts are usually awarded on the basis of a multicriteria evaluation, with price as one of the most salient criteria. To ensure the project's success, an owner usually has to invest enough time and effort during scoping and early design to define a program, scope, and budget, ready for procurement and price generation. However, this process can become a burden for the owner and may lengthen the project development duration. As an alternative to the traditional DB, the progressive design-build (PDB) approach permits the selection of the DB team prior to defining the project program and/or budget. PDB has the advantage of maintaining a single point of accountability and allowing team selection based mainly on qualifications, with a limited consideration of price. Under PDB, the selected team works with the project stakeholders during the early design stage, while helping the owner balance scope and budget. However, the key to the effectiveness of PDB is its provision for the ongoing and complete involvement of the owner in the early design phase. Due to the differences between PDB and the other project delivery methods (e.g., traditional DB), project teams must carefully consider several factors to ensure its successful implementation. The research team conducted a case study of the University of Washington's pilot PDB project to complete the West Campus Utility Plant (WCUP). This paper carefully explores and summarizes the project's entire delivery process (e.g., planning, solicitation, design, and construction), its organizational structures, and the project performance outcomes. The lessons learned from the WCUP project will contribute to best practices for future PDB implementation.
Keywords
Progressive Design Build; Project Delivery Method
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
Lin, Lin; Chen, Xueming (Jimmy); Moudon, Anne Vernez. (2021). Measuring the Urban Forms of Shanghai’s City Center and Its New Districts: A Neighborhood-Level Comparative Analysis. Sustainability, 13(15).
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Abstract
Rapid urban expansion has radically transformed the city centers and the new districts of Chinese cities. Both areas have undergone unique redevelopment and development over the past decades, generating unique urban forms worthy of study. To date, few studies have investigated development patterns and land use intensities at the neighborhood level. The present study aims to fill the gap and compare the densities of different types of developments and the spatial compositions of different commercial uses at the neighborhood level. We captured the attributes of their built environment that support instrumental activities of daily living of 710 neighborhoods centered on the public elementary schools of the entire Shanghai municipality using application programming interfaces provided in Baidu Map services. The 200 m neighborhood provided the best fit to capture the variations of the built environment. Overall, city center neighborhoods had significantly higher residential densities and housed more daily routine destinations than their counterparts in the new districts. Unexpectedly, however, the total length of streets was considerably smaller in city-center neighborhoods, likely reflecting the prominence of the wide multilane vehicular roads surrounding large center city redevelopment projects. The findings point to convergence between the city center's urban forms and that of the new districts.
Keywords
Quantifying Spatiotemporal Patterns; Fast-food Restaurants; Instrumental Activities; Physical-activity; Chinese Cities; Land; Schools; Redevelopment; Expansion; Transformation; Built Environment; Planning; Neighborhood; Urban Form; Shanghai
Soltaninejad, Mostafa; Fardhosseini, Mohammad Sadra; Kim, Yong Woo. (2021). Safety Climate and Productivity Improvement of Construction Workplaces Through the 6S System: Mixed-Method Analysis of 5S and Safety Integration. International Journal Of Occupational Safety & Ergonomics, 28(3), 1811-1821.
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Abstract
The purpose of this study is to develop a framework for integrating essential safety practices (visualization, job safety analysis and plan-do-check-act) into 5S steps and validate it. First, 18 interviews with a snowball sample of construction workers, safety representatives, supervisors and site and project managers were conducted. A grounded theory method was utilized to code the interview data. The results revealed that the studied construction companies implement a systematic safety-based methodology to minimize construction work injuries. Second, to validate the proposed framework, a pre-test and post-test study was applied. The case and control groups (26 participants) answered a 6S questionnaire before the 6S system and 1 month after implementation. The results revealed that safety climate and productivity significantly increased for the case group but reduced for the control group during time.
Keywords
5s Method; 6s System; Grounded Theory; Lean Construction; Productivity; Safety Climate; Health; Management; Leadership; Culture; Impact
Shim, Yukyung; Jeong, Jaemin; Jeong, Jaewook; Lee, Jaehyun; Kim, Yongwoo. (2022). Comparative Analysis of the National Fatality Rate in Construction Industry Using Time-series Approach and Equivalent Evaluation Conditions. International Journal Of Environmental Research And Public Health, 19(4).
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Abstract
Fatality rates such as fatalities per full-time equivalent workers are officially used to compare the risk level of the construction industry among various countries. However, each country evaluates the fatality rate using different conditions. This paper presents the comparison of fatality rates of various countries using conventional (national data) and pair (equivalent condition) methods through a time-series approach. The research was conducted in three stages. The risk level was evaluated in order in South Korea (1.54), Japan (0.84), Mexico (0.83), China (0.70), United Kingdom (0.15), and Singapore (0.13) in terms of national data. However, the risk level was re-evaluated in order in China (2.27), South Korea (2.05), Mexico (1.23), Singapore (0.98), Japan (0.80), and United Kingdom (0.47) in terms of equivalent conditions. The risk level of each can be changed when the fatality rate is compared under given equivalent conditions.
Keywords
Fatality Rate; Risk Level; Full-time Equivalent Workers; Equivalent Evaluation Conditions; Time-series Analysis; Occupational Accidents; United-states; Injuries; Korea; Work; Comparative Analysis; Equivalence; Manual Workers; Risk Levels; Construction Industry; Fatalities; Risk Assessment; Safety Management; Industrial Accidents; Environmental Protection; Time Series; Accident Investigations; United Kingdom--uk; South Korea; Mexico; United States--us; Singapore; China; Japan
Kim, Taehoon; Kim, Yong-woo; Lee, Dongmin; Kim, Minju. (2022). Reinforcement Learning Approach To Scheduling Of Precast Concrete Production. Journal Of Cleaner Production, 336.
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Abstract
The production scheduling of precast concrete (PC) is essential for successfully completing PC construction projects. The dispatching rules, widely used in practice, have the limitation that the best rule differs according to the shop conditions. In addition, mathematical programming and the metaheuristic approach, which would improve performance, entail more computational time with increasing problem size, let alone its models being revised as the problem size changes. This study proposes a PC production scheduling model based on a reinforcement learning approach, which has the advantages of a general capacity to solve various problem conditions with fast computation time and good performance in real-time. The experimental study shows that the proposed model outperformed other methods by 4-12% of the total tardiness and showed an average winning rate of 77.0%. The proposed model could contribute to the successful completion of off-site construction projects by supporting the stable progress of PC construction.
Keywords
Precast Concrete; Reinforcement Learning; Deep Q -network; Production Scheduling; Minimize; Model
El-Anwar, Omar; El-Rayes, Khaled; Elnashai, Amr. (2010). Minimization of Socioeconomic Disruption for Displaced Populations Following Disasters. Disasters, 34(3), 865 – 883.
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Abstract
In the aftermath of catastrophic natural disasters such as hurricanes, tsunamis and earthquakes, emergency management agencies come under intense pressure to provide temporary housing to address the large-scale displacement of the vulnerable population. Temporary housing is essential to enable displaced families to reestablish their normal daily activities until permanent housing solutions can be provided. Temporary housing decisions, however, have often been criticized for their failure to fulfil the socioeconomic needs of the displaced families within acceptable budgets. This paper presents the development of (1) socioeconomic disruption metrics that are capable of quantifying the socioeconomic impacts of temporary housing decisions on displaced populations; and (2) a robust multi-objective optimization model for temporary housing that is capable of simultaneously minimizing socioeconomic disruptions and public expenditures in an effective and efficient manner. A large-scale application example is optimized to illustrate the use of the model and demonstrate its capabilities ingenerating optimal plans for realistic temporary housing problems.
Keywords
Natural Disasters; Hurricanes; Disaster Relief; Temporary Housing; Tsunamis; Multi-objective Optimization; Post-disaster Recovery; Social Welfare; Socioeconomic Disruption
Abramson, Daniel Benjamin. (2011). Places for the Gods: Urban Planning as Orthopraxy and Heteropraxy in China. Environment & Planning D: Society & Space, 29(1), 67 – 88.
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Abstract
Among the many revivals of older urban practices in China since the death of Mao and the Reforms of Deng Xiaoping is the resurgence of unofficial folk-religious space. As a national phenomenon, it is an uneven process, but where it has become prevalent, it presents challenges both to official standard urban-planning practice, as well as to the public presentation of planning practice. This paper describes how nonstandard practices can emerge in the current context of rapid urbanization, which itself is a force for standardized urban spatial practices in terms of Chinese domestic cultural and political institutions as well as global capital flows. Both local and translocal actors, navigating among various conflicting standards of practice and discourse, can find room to resist hegemony, maintain identity, and innovate. The political and bureaucratic ritualization of planning practice, however, conceals this fact.
Keywords
Urban Planning -- Social Aspects; Urban Policy; Urbanization; Hegemony; Cultural Policy; Social Conditions In China; Social Aspects; China; Late Imperial China; Standardization; Property; Shanghai; Culture; Space; State
Duncan, Glen E.; Dansie, Elizabeth J.; Strachan, Eric; Munsell, Melissa; Huang, Ruizhu; Moudon, Anne Vernez; Goldberg, Jack; Buchwald, Dedra. (2012). Genetic and Environmental Influences on Residential Location in the US. Health & Place, 18(3), 515 – 519.
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Abstract
We used a classical twin design and measures of neighborhood walkability and social deprivation, using each twin's street address, to examine genetic and environmental influences on the residential location of 1389 same-sex pairs from a US community-based twin registry. Within-pair correlations and structural equation models estimated these influences on walkability among younger (ages 18-24.9) and older (ages 25+) twins. Adjusting for social deprivation, walkability of residential location was primarily influenced by common environment with lesser contributions of unique environment and genetic factors among younger twins, while unique environment most strongly influenced walkability, with small genetic and common environment effects, among older twins. Thus, minimal variance in walkability was explained by shared genetic effects in younger and older twins, and confirms the importance of environmental factors in walkability of residential locations. (c) 2012 Elsevier Ltd. All rights reserved.
Keywords
Homesites; Community Life -- Social Aspects; Structural Equation Modeling; Genetics; Analysis Of Variance; Environmental Health; Walking; United States; Environment; Neighborhood; Twins; Walkability; Physical-activity; Twin Registry; Epidemiology; Preferences; Selection; Zygosity
Yang, Jiawen; Shen, Qing; Shen, Jinzhen; He, Canfei. (2012). Transport Impacts of Clustered Development in Beijing: Compact Development Versus Overconcentration. Urban Studies, 49(6), 1315 – 1331.
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Abstract
This research aims to inform the compact city discussion with a case study of Beijing, where urban planning has emphasised clustered suburban development in the past half-century. It uses three decades of census data to describe Beijing's spatial development trajectory and a household survey to assess its transport impacts. The research reveals an overconcentration of urban activities as a result of the featureless expansion of the central built-up area and the absorption of the suburban clusters; and, a lengthened commuting time stemming from the observed spatial development pattern. Beijing's experience adds to the existing literature by informing the search for good city forms in urban areas of high density. It is essential to differentiate compact development from overconcentration when combating sprawling development. Developing and maintaining suburban nodal characteristics around public transit can reduce travel in high-density urban areas.
Keywords
Jobs-housing Balance; Commuting Patterns; Urban; Growth; City; Towns