• Journal of the Korea Institute of Building Construction
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• v.12 no.3
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• pp.358-368
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• 2012

On most construction sites, the arrangement of tower cranes is decided by site engineers based on their own experience, which can cause cost overruns and delays in the lifting work. Although many researchers have conducted studies on tower crane arrangement using computer modeling and knowledge-based expert systems as well as mathematical models, no research has aimed to develop an algorithm to identify an optimum solution among several alternatives for installation areas of tower cranes satisfying the conditions of lifting work. The objective of this study is to develop an automatic arrangement algorithm for tower cranes used in high-rise apartment construction. First, as a new concept, a possible installation area of tower cranes was suggested. Second, after proposing several alternatives based on the installation points suggested in this study, an algorithm analyzing the economic feasibility of tower cranes was developed considering the rental, installation and removal costs. Third, a case study was conducted to prove the validity of the developed algorithm for selecting and installing an effective set of tower cranes at minimum cost.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1154-1157
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• 2005

This report is to do design management for constructability review of high quality exposed concrete, which is used increasingly in recent. To secure systematic management at design phase, we reviewed each definition and work at each design phase, we define high quality exposed concrete, a part of architectural concrete, as "an exposed concrete which has well ordered joint & is in pursuit of smooth surface." We reviewed requirements and influential factor to obtain High quality finishing surface and compared construction process of high quality exposed concrete with that of other finishing method. Management method at each design phase for constructability review to meet additional works and requirements is presented.

• Journal of the Korea Institute of Building Construction
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• v.18 no.6
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• pp.603-609
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• 2018

It has been widely-reported that the quality of life in Korea is lower than that of the economic growth. In particular, construction managers are reported to have a lower quality of life compared to people in other job types due to the specific nature of the tasks they have to carry out. These include early work attendance time and fewer holidays. In this respect, the aim of this study is to analyse construction managers' requirements on work-life balance. The results showed that the working hours of construction managers were long and their leisure hours were shorter. The requirements for work-life balance were in the order of non-working time, working time, salary, and job security. The requirements by group showed a statistically significant difference in work hours. The requirements on the shortening of work hours were highest in the group of "section chiefs and deputy heads" and lowest in the group of "department heads" and up. It is hoped that the results of this study will be used as basic data for future government-level policy making and construction companies' business directions in relation to the improvement of workers' work-life balance.

• Journal of the Korea Institute of Building Construction
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• v.13 no.6
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• pp.594-601
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• 2013

One of the important problems associated with building demolition is the dust generated during the work. The only way to reduce the demolition dust is to use a dust net during water spraying. However, it is difficult to supply the necessary amount of water to remove demolition dust, thus making it difficult to apply this method on a demolition site. This work attempted to find an alternative approach to dust removal by incorporating surfactant and high range AE water reducer in the water being sprayed. Through the experiment, it was found that the addition of surfactant did not contribute to the removal of demolition dust. However, the use of high range AE water reducer showed better performance than spraying plain water, indicating that some amount of demolition dust had been adsorbed on the high range AE water reducer.

• Journal of the Korea Institute of Building Construction
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• v.21 no.6
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• pp.653-664
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• 2021

As the construction standards for energy-saving eco-friendly housing have recently been strengthened, the proportion of window work has increased with the demand for high-efficiency housing. Windows have high frequency of use, and there is the potential for many defects to occur depending on the characteristics of construction. According to a government agency's survey of defects in public rental apartment housing, defects in the windows work accounted for the highest portion of complaints received. Accordingly, related previous studies were considered, and it was found that the existing studies in Korea lacked research that reflected the construction characteristics of window work and the importance of maintenance. In addition, existing overseas studies considered both the constructor and the resident's position, considering the cost aspect together, and showed a trend of structuring the relationship between defects and causes. Therefore, this study will analyze the causes of defects that can occur in the construction phase of the windows work, reflect the construction characteristics, and derive major factors that consider the importance of maintenance based on the possibility of recurrence after repairing defects. Ultimately, this research will contribute to preventing defects in the construction phase and reducing maintenance costs by presenting a highly effective defect management plan through selecting the major factors for each defect type that can be intuitively judged by analyzing the causal relationship between defect types and causes.

• Korean Journal of Construction Engineering and Management
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• v.23 no.6
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• pp.3-14
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• 2022

Quantitative analysis of the number of construction workers and construction period can present a new standard for appropriate personnel. This study presents a Queueing model that predicts the execution time of work procedures, the most important factor among work efficiency indicators. During the working cycle of apartment frame construction the same process tends to be repeated the volume of contruction. Based on these characteristics, this study used a Queueing Model and analyzed reference layer cycle of the delayed frame construction. After adjusting the number of people and the construction period, the performance of the model was analyzed and suggested. This study aims to support the decision making of personnel distribution according to the volume of construction by performing a performance analysis of the Queueing Model.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1089-1093
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• 2005

Proving the effect of lean construction has yet to be done for its staying poor basic building though there has been efforts and wants to introduce the theory and concept of lean construction in practical site. Therefore, we need to specify the methods of productivity improvement and construction process through various adaptations in the site. Also, to apply such improvement methods systematically, we need active participation of owners, contractors and supply chain members in relation to construction industry and are also require appropriate methods to adapt. At first, this study thinks over the techniques of lean construction that has been verified through studies carried before. For second, it selects the technique of lean construction with the practicality in the construction site. For third, it is aimed to make a manual of lean process management by the use of TACT and V.S.M. For fifth, it will show the method of management for repeated activity and develop a guide-line and procedure that applies the concept of work sequence and resource equalization to each phase of process management. At last, it will show methods of reflecting V.S.M. to improve and grasp the waste factor from the step of managing an activity process and develop the form to analyze the waste in construction site by mapping the value flow.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.616-623
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• 2022

Some regions and states, such as Wyoming, have harsh weather conditions, forcing most transportation projects to be completed under tight schedules. However, construction projects are not only delayed by weather conditions, but also delayed by other factors such as contractor's competency, resource availability, coordination issues, and safety. Also, the construction method, geographical location of the projects, and inability to follow baseline schedules accurately due to the contractor's resource allocation are also reasons for the delay. This paper discusses the main reasons for the delay in the public transportation projects based on Daily Work Reports (DWRs) from five different transportation projects of the last three years in Wyoming. This paper focuses on the inconsistencies of the contractor's schedules to complete the project according to the baseline schedule. First, the authors collected DWRs and baseline schedules from the Wyoming Department of Transportation (WYDOT). Second, the DWR data are compared against the baseline schedules to determine the reasons for delaying their significance. Finally, the paper presents the recommendations to mitigate the effects of delays on public transportation projects as well as to improve the documentation process of DWR data.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.413-423
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• 2015

Exterior Insulation and Finishing System(EIFS) is recognized as a promising alternative for energy reduction as energy reduction ratio of apartment is to be increased from 40% to 60% in 2017. However, EIFS is not actively applied to apartment because additional construction costs and duration are required for the current existing construction method of EIFS. Therefore, this study proposes a conceptual framework for concurrent construction method of EIFS which can reduce construction costs and duration by working sequentially from frame work to exterior insulation finishing work, and then verify the method's feasibility by analyzing a case study. It has been proven from the analysis that concurrent construction method of EIFS reduces 6.7% of construction duration and 13% of construction costs compared with the conventional exiting method. The proposed method is expected to contribute to invigorated application of EIFS to apartment.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.57-67
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• 2022

Tower cranes have an unstable superstructure, which means that there is a very high risk of accidents. It is necessary to establish preventive measures to ensure the safety of tower cranes at a time when active efforts are being made to reduce safety accidents involving tower cranes. As such, the purpose of this study is to analyze disaster cases to ensure the safety of tower cranes. For this study, 260 cases of tower crane disasters filed with the Korea Occupational Safety and Health Agency from July 2012 to July 2020 were analyzed. Through this analysis, it was found that lifting work was the most common of the work types, at 45.3%; while of the types of disasters, accidents caused by falls were the most common type, at 35.8%. In addition, with regard to the cause of accidents, work method defects was found to be the highest, at 38.8%. In the future, the findings of this study will be used as basic data to guide the establishment of policy to prevent tower crane accidents.