• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.977-980
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• 2008

Recently, the study on the application of SCC(Self-Compacting Concrete) is actively underway, in order to solve the lack of flowability and the poor compacting which is one of the chronic problems of tunnel lining concrete. The aim of this study is that to verify the validity of the application of SCLC(Self-Compacting Lining Concrete) for tunnel lining concrete and to examine the characteristic of flowing and mechanics of SCLC in term of comparing before and after casting SCLC was developed by Packing Factor mix method and casted in field mix-design according to the condition of site and the characteristic of aggregate. Before casting, the tests of the capability of flowability and durability was performed by slump flow, air void and so on. Additionally, the slump flow loss is measured to evaluated the possibility of cast-in-place. Furthermore, considering on the first time SCLC casting applied to the tunnel lining in Korea, it is provided that the careful items and the correct way for construction when applied the SCLC on site.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.5
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• pp.218-226
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• 2011

Low heat concrete using strontium hydroxide based latent heat material was manufactured in ready-mixed concrete batcher plant and its fundamental properties were tested. As a result of B/P test, its applicability to the construction site was verified. After B/P test, low heat concrete using strontium hydroxide based latent heat material was applied to the real construction site of bridge footing. Through the analysis and the actual measurement of the hydration heat of the concrete footing, the reduction effect of hydration heat and thermal crack was confirmed.

• Tunnel and Underground Space
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• v.18 no.4
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• pp.263-271
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• 2008

3D seismic tomography technique was assessed for applicability of developed 3D tomography algorithm based on Fresnel volume in the dam-planned area. Reconstructed 3D tomogram based on Fresnel volume and Fast Marching Method(FMM) reveals similar velocity structure to the other geotechnical survey results. With the correlation analysis between RMR data and seismic velocity information, it could provide reliable information of rock mass rate. The applicability of 3D seismic tomography was verified in this study. It would be expected to apply 3D tomography with new developed first arrival calculation and inversion algorithm to the engineering field economically.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.767-771
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• 2008

From industrial field spearhead IT and new create an added value and market with fusion of traditional industry composition researches actively to be in the process of advancing. The application possibility of high-tech IT technique is coming to be high in construction industry. Currently, the user requirements that upgrade existing system to high-tech construction project information system combined construction CALS system applying in road/river business management service with high-tech IT such as ubiquitous and mobile techniques are increasing. Therefore, the objective of this study is to verify site application of RFID and mobile equipment for applying in high-tech field with ubiquitous and mobile techniques so that construction CALS system gets advanced increasingly.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.128-137
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• 2023

Purpose: This study proposes a way to improve quality and increase safety by studying a method that allows the system scaffolding, which is partly used for high-altitude work at construction sites, to be applied to various types of structures in shipbuilding and plant industry sites. Method: A fact-finding survey was conducted targeting 8 companies, and a plan was established that reflected the opinions of the field survey and the practitioners and experts by analyzing the literature and the Internet survey. Result: Through analysis of related patents, FGI with companies, etc., we discovered the possibility of application expansion through research and development of materials that can be applied to various types and improvement plans for enhancing the professionalism of construction companies. Conclusion: System scaffolding has a high importance in terms of safety, but related research around the world is sluggish. Therefore, it will be possible to meet the demands for quality and safety by enhancing the software expertise and developing and researching user materials that can be applied to various types.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.793-796
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• 2005

금형공장의 생산 일정관리에 있어서 실제 가공작업에 대한 실적데이터의 집계는 매우 중요하지만, 이러한 작업상황을 기록하는 것에 대해서 현장 작업자는 비협조적이고 반감을 갖고 있는 실정이다. 현장에서는 작업자의 개입없이 CNC 장비의 컨트롤러와의 직접적인 인터페이스를 통해서 신호를 추출하고 자동으로 작업상황을 파악할 수 있는 시스템을 구축하려고 시도하고 있지만, 컨트롤러 메이커마다 다르게 적용해야 하고 많은 비용을 요구한다. 이러한 이유로 본 연구에서는 저가의 PC 카메라를 장비에 설치하여 가공상황에 대한 동영상을 수집하고 영상처리 알고리즘을 적용하여 가공시간을 집계하는 방법을 제안한다. 제안된 방법은 CNC 컨트롤러에 독립적으로 운용되며 저렴하게 시스템을 구축할 수 있는 장점이 있다. 본 연구에서는 무인가공과 유인가공 상황에 시범적으로 적용 및 운영함으로써 시스템의 활용가능성을 살펴보았다.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.289-302
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• 2019

As the occurrence of ground subsidence near the excavation site increases recently, studies are being conducted to predict the possibility of ground subsidence prior to excavation. In this study, the ground subsidence risk rating for pre-excavation (GSRp) developed by the previous study was applied to actual excavation sites to verify its applicability. The final results for the evaluation of the ground subsidence risk level for five excavation sites revealed that GSRp scores were calculated between 40 and 79 points and classified mainly into grades II (Good Ground)~III (Fair Ground). In order to verify the evaluation method, the obtained GSRp grades were compared with the measured horizontal displacements. The horizontal displacements measured in five excavation sites were between 25% and 47% of the allowable displacement, which were well agreed with the low subsidence risk level obtained from GSRp calculation. It is expected that the GSRp method can be used as an evaluation tool for predicting the risk of ground subsidence before excavation if GSRp is verified and supplemented through the additional research for the poor soil with the high risk of ground subsidence.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.563-574
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• 2007

Laser induced breakdown spectroscopy (LIBS) is a recently developed analytical technique that is based upon the measurement of emission lines generated by atomic species close to the surface of the sample, thus allowing their chemical detection, identification and quantification. With powerful advantages of LIBS compared to the conventional analytical methodology, this technique can be applied in the detection of heavy metals in the field. LIBS allows the rapid analysis by avoiding laborious chemical steps. LES have already been applied for the determination of element concentration in a wide range of materials in the solid, liquid and gaseous phase with simplicity of the instrument and diversity of the analytical application. These feasibility of rapid multi elemental analysis are appealing proprieties for the in-situ analytical technique in geochemical investigation, exploration and environmental analysis. There remain still some limitations to be solved for LIBS to be applied in soil environment as an in-situ analytical technology. We would like to provide the basic principle related to the plasma formation and laser-induced breakdown of sample materials. In addition, the matrix effect, laser properties and the various factors affecting on the analytical signal of LIBS was dealt with to enhance understanding of LIBS through literature review. Ultimately, it was investigated the feasibility of LIBS application in soil environment monitoring by considering the basic idea to enhance the data quality of LIBS including the calibration method for the various effects on the analytical signal of LIBS.

• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.12-18
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• 2024

High-rise, large-scale, and diversification of buildings are possible, and the reduction of concrete cross-sections reduces the weight of the structure, thereby increasing or decreasing the height of the floor, securing a large number of floors at the same height, securing a large effective space, and reducing the amount of materials, rebar, and concrete used for designating the foundation floor. In terms of site construction and quality, a low water binder ratio can reduce the occurrence of dry shrinkage and minimize bleeding on the concrete surface. It has the advantage of securing self-fulfilling properties by improving fluidity by using high-performance sensitizers, making it easier to construct the site, and shortening the mold removal period by expressing early strength of concrete. In particular, with the rapid development of concrete-related construction technology in recent years, the application of ultra-high-strength concrete with a design standard strength of 100 MPa or higher is expanding in high-rise buildings. However, although high-rise buildings with more than 120 stories have recently been ordered or scheduled in Korea, the research results of developing ultra-high-strength concrete with more than 130 MPa class considering field applicability and testing and evaluating the actual applicability in the field are insufficient. In this study, in order to confirm the applicability of ultra-high-strength concrete in the field, a preliminary experiment for the member of a reduced simulation was conducted to find the optimal mixing ratio studied through various indoor basic experiments. After that, 130 MPa-class ultra-high-strength concrete was produced in a ready-mixed concrete factory in a mock member similar to the life size, and the flow characteristics, strength characteristics, and hydration heat of concrete were experimentally studied through on-site pump pressing.

• Journal of the Korea Institute of Building Construction
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• v.21 no.1
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• pp.41-49
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• 2021

This study was to solve the lift problem of the existing unit curtain wall type by using the vertical material mullion as a rail in curtain wall, which is recently used as an external finishing material for high-rise buildings. It has been shown that the application of the curtain wall mullion's rail can be quantified even at 20m/sec wind speed through the Mock-Up test. Based on the sites selected for comparison of construction methods, it was analyzed that the construction period could be shortened by 48 days, or about 20 percent. It was analyzed that the number of construction workers could be reduced by about 33 percent from the previous nine to six. Based on these results, assuming the installation of curtain wall units of 10,000㎡, it is judged that construction cost can be reduced by 80% or more.