• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2003.10a
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• pp.55-72
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• 2003

Dam is a barrier constructed to divert, hold water and raise its level for purpose of water supply, irrigation, power generation, flood control, and recreational facilities, etc. Therefore, there are many inevitable environmental impacts on dam construction. We need some better tools to predict the impacts and mitigate measures before and after dam construction. For this purpose I discussed several feasible suggestions and provisions mainly related to environmental impact assessment.

• Korean Architects
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• v.3 no.8 s.8
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• pp.27-32
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• 1968

This article discusses at a basic level the process of chimney construction. The concept, design, and operation can be understood easily. This, of course, is the first step to orderly construction. The selection of the boiler as to type, capacity, etc. was summarized in brief. The over all planning of the boiler and chimney together was the main object of this article. The architectural books covering this subject are very technical and this article tries to make the understanding of the basic principles more easy for the beginner in architecture.

• Journal of Computational Design and Engineering
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• v.2 no.1
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• pp.16-25
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• 2015

Since construction projects are large and complex, it is especially important to provide concurrent construction process to BIM models with construction automation. In particular, the schematic Quantity Take-Off (QTO) estimation on the BIM models is a strategy, which can be used to assist decision making in just minutes, because 70-80% of construction costs are determined by designers' decisions in the early design stage. This paper suggests a QTO process and a QTO prototype system within the building frame of Open BIM to improve the low reliability of estimation in the early design stage. The research consists of the following four steps: (1) analyzing Level of Detail (LOD) at the early design stage to apply to the QTO process and system, (2) BIM modeling for Open BIM based QTO, (3) checking the quality of the BIM model based on the checklist for applying to QTO and improving constructability, and (4) developing and verifying a QTO prototype system. The proposed QTO system is useful for improving the reliability of schematic estimation through decreasing risk factors and shortening time required.

• Safety and Health at Work
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• v.5 no.3
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• pp.125-130
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• 2014

Background: Construction industry is among the most hazardous industries, and needs a comprehensive and simple-to-administer tool to continuously assess and promote its health and safety performance. Methods: Through the study of various standard systems (mainly Health, Safety, and Environment Management System; Occupational Health and Safety Assessment Series 180001; and British Standard, occupational health and safety management systems-Guide 8800), seven main elements were determined for the desired framework, and then, by reviewing literature, factors affecting these main elements were determined. The relative importance of each element and its related factors was calculated at organizational and project levels. The provided framework was then implemented in three construction companies, and results were compared together. Results: The results of the study show that the relative importance of the main elements and their related factors differ between organizational and project levels: leadership and commitment are the most important elements at the organization level, whereas risk assessment and management are most important at the project level. Conclusion: The present study demonstrated that the framework is easy to administer, and by interpreting the results, the main factors leading to the present condition of companies can be determined.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.185-186
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• 2015

The use of non-bearing lightweight wall has increased recently due to the increase of high-rise buildings and supply of long-life housing. Lightweight wall has advantages such as reducing the self-weight of the building, convenience in installation, and shortening construction period, however, must have a sufficient strength to external force. This study standardized the stiffness (static horizontal load resistance) test method for lightweight walls by using the actual impact load obtained through the load analysis test conducted in the previous studies. The size of specimen was set up as height 2.4m and width 3.0m. Test apparatus and test methods were referred to BS 5234-2:1992. However, the loading level applied to the specimen was divided into 3 steps (3000N, 1000N, 500N) that can be applied selectively depending on the purpose of the wall. The deformation characteristics according to the same loading level were vary depending on the specimen's type, and the evaluation criteria for functional damage may vary depending on the material, method of construction, and purpose of wall. Therefore, we did not suggest unified evaluation criteria of the stiffness to the test results.

• Wind and Structures
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• v.32 no.5
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• pp.405-421
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• 2021

To gain insight into the wind-induced safety concerns associated with attached tower cranes during the construction of super-tall buildings, a 606 m level frame-core tube super-tall building is selected to investigate the wind-induced vibration response and fragility of an outer-attached tower crane at all stages of construction. The wind velocity time history samples are artificially generated and used to perform dynamic response analyses of the crane to observe the effects of wind velocity and wind direction under its working and non-working resting state. The adverse effects of the relative displacement response at different connection supports are also identified. The wind-resistant fragility curves of the crane are obtained by introducing the concept of incremental dynamic analysis. The results from the investigation indicate that a large relative displacement between the supports can substantially amplify the response of the crane at high levels. Such an effect becomes more serious when the lifting arm is perpendicular to the plane of the connection supports. The flexibility of super-tall buildings should be considered in the design of outer-attached tower cranes, especially for anchorage systems. Fragility analysis can be used to specify the maximum appropriate height of the tower crane for each performance level.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.784-791
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• 2022

Tack coat is a thin layer of asphalt between the existing pavement and asphalt overlay. During construction, insufficient tack coat layering can later cause surface defects such as slippage, shoving, and rutting. This paper proposed a method for tack coat inspection improvement using an unmanned aerial vehicle (UAV) and deep learning neural network for automatic non-uniform assessment of the applied tack coat area. In this method, the drone-captured images are exploited for assessment using a combination of Mask R-CNN and Grey Level Co-occurrence Matrix (GLCM). Mask R-CNN is utilized to detect the tack coat region and segment the region of interest from the surroundings. GLCM is used to analyze the texture of the segmented region and measure the uniformity and non-uniformity of the tack coat on the existing pavements. The results of the field experiment showed both the intersection over union of Mask R-CNN and the non-uniformity measured by GLCM were promising with respect to their accuracy. The proposed method is automatic and cost-efficient, which would be of value to state Departments of Transportation for better management of their work in pavement construction and rehabilitation.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.435-439
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• 2015

It is important for Singaporean companies to manage the multifaceted risks when forming international construction joint ventures (ICJVs) with developing countries. The objectives of this study are to assess the risks associated with Singaporean ICJVs with developing countries, and investigate the risk allocation preferences in these ICJVs. To fulfill these objectives, a literature review was carried out and a questionnaire survey was performed with 38 professionals. The survey results reported "political instability" as the most critical risk, and market level risks were less critical than country and project level risks. Additionally, the results showed agreement on the risk ranking between building and infrastructure ICJVs, despite significant differences in the criticalities of five risks. Furthermore, five risks were preferably allocated to host and foreign partners, respectively, while 13 risks could be shared among partners. As few studies have explored the risk allocation preferences in ICJVs, this study expands the literature. Also, the identification of the risks allows other companies to customize their own lists of critical risks, while the preferred risk allocation provides valuable information for companies from various countries that intend to form ICJVs with developing countries. Thus, this study contributes to the global body of knowledge relating to ICJVs.

• Journal of the Korea Institute of Building Construction
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• v.24 no.5
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• pp.587-598
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• 2024

In this paper, we attempted to analyze vibration properties depending on construction deviations of concrete slab, and 12 specimens of 8 4 types were selected. The floor impact sound blocking performance measurement method was performed according to the standard weight impact source method among the KS F 2810 field floor impact sound blocking performance measurement methods. As a result, as the compressive strength of the slab increased, the amount of vibration decreased at a frequency of 31.5Hz, while the amount of vibration increased at 40 to 100Hz. As the slab thickness increased, the vibration level increased at a frequency of 31.5Hz and decreased significantly at frequencies between 40 and 100Hz. The level of vibration decreased with the thickness of the weakly bonded center point.

• KIEAE Journal
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• v.1 no.2
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• pp.13-19
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• 2001

Recently, With the increase of income level, many people desire to have agreeable and quiet surrounding. However, the extent and time of the exposure to construction noise and vibration is increasing, which is a factor that ruins the quietness of the surrounding and increasingly raises interests in its effects. In this point, this study attempts to survey the characteristics of construction vibration by SD(Sand drain) method in construction field. In addition, the result of study is presumed to be usable as the fundamental materials for an efficient counter-plan in case of the public resentment in relations to the construction vibration occurring henceforth.