• Journal of Korean Society of Steel Construction
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• v.21 no.4
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• pp.385-392
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• 2009

In this study, the confining effect of the proposed steel jackets and GFRP tubes for concrete was investigated. The new steel jacket differs from the existing steel jacket in terms of installation technique and behavior. Thus, it is necessary to assess its confining effect on concrete. Moreover, the method was compared to GFRP tubes to investigate its strong and weak points. The confining effect of the proposed steel jacket was shown to correspond with that presented in the previous researches. The GFRP jacketing method, however, does not show any confining effect in some cases, according to the tube thickness and concrete peak strength as such, the previous assessment equation cannot be used in such cases. Thus, in this study, a new method of assessing the peak strength of confined concrete was suggested, and the minimum thickness was determined to show the confining effect. Lastly, the ultimate strains of concrete that had been confined through the two methods were compared to assess their ductile behavior.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.1
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• pp.1-9
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• 2010

Pile reinforcement systems with enlarged upper section are newly introduced by using a mechanism that most of horizontal forces are resisted in the upper part of the pile. The new systems are expected to be effectively applicable to the marine structures including port and harbor facilities. In this study, three different reinforcement methods such as bucket pile type, top base pile type, and grouting reinforcement type were utilized in the 3-D. numerical simulations. The parametric study deals with the effects of various factors including soil types and stratigraphy, reinforcement methods, type and dimension of the pile on the lateral behaviors of the pile. The results show that the reinforcement method with bucket pile is the most efficient one compared to the top base pile type and grouting reinforcement type.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.55-65
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• 2008

This study introduced a new method to retrofit RC columns with lap splice that do not have enough ductility during an earthquake. The new method used mechanical external pressure and split steel plates around the RC columns. The introduced method does not require grouting the gap between jacket and concrete surface. In this study, 45 concrete cylinders were manufactured with varyingstrengths and part of them was retrofitted with split steel jackets under a lateral confining stress. The effect of the new method was verified by comparing the results from the compressive tests of retrofitted and unretrofitted cylinders. The steel jacket that was built following the new method showed good results of increasing the compressive strength and ductility of concrete cylinders. The thicker steel jackets showed larger compressive strength, however, the ductility at failure depends on their welding quality.

• Magazine of the Korea Concrete Institute
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• v.7 no.6
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• pp.64-73
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• 1995

• Magazine of the Korea Concrete Institute
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• v.7 no.6
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• pp.50-63
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• 1995

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.3
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• pp.77-86
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• 2004

The retrofit priority of existing and retrofitted bridges is examined and compared to determine effectively the seismic retrofit method of bridges. For the retrofit prioritization of bridges a quantitative procedure is proposed firstly based on seismic damage probabilities and total failure cost due to the damage of seismic vulnerable components. Using the proposed procedure, the retrofit priority of four typical girder-type bridges is determined. In addition, the ranking indices of bridges retrofitted by steel jackets and cable restrainers are revaluated for comparing with the results of existing bridges. Application of retrofitting method can considerably decreases damage possibilities of retrofitted components but may increases those of adjacent vulnerable components. Therefore, the seismic retrofitting effects based on the global motions of existing and retrofitted bridges should be examined to determine efficiently the retrofitting method. For evaluating the retrofitting effects the ranking indices obtained from the proposed procedure is found to be utilized effectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.479-480
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• 2010

The efforts to achieve high-performance, durable reinforced concrete structures have increased the demands for improving the performance of both the concrete and the reinforcing materials. Researches for the hybrid reinforcing technique, which is maximizing the performance of high-strength concrete structures by applying the combination of high performance reinforcing materials, were performed in this study.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.532-534
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• 2022

본 논문에서는 미생 드라마 비디오들을 토대로 구축한 비디오 인물 개체 분할 데이터 집합인 MHIS를 소개하고, 등장인물 클래스 간의 심각한 데이터 불균형 문제를 효과적으로 해결하기 위한 새로운 비디오 데이터 보강 기법인 CDVA를 제안한다. 기존의 비디오 데이터 보강 기법들과는 달리, 새로운 CDVA 보강 기법은 비디오의 시공간적 맥락을 충분히 고려해서 부족한 인물 클래스의 훈련 비디오 데이터들을 추가 생성함으로써, 비디오 개체 분할 신경망 모델의 성능을 효과적으로 개선시킬 수 있다. 본 논문에서는 정량 및 정성 실험들을 통해, 제안 비디오 데이터 보강 기법의 우수성을 입증한다.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2017.10a
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• pp.96-99
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• 2017

현재 시행되고 있는 수목 보강의 단점을 보완할 수 있는 새로운 보강법을 개발하기 위하여 거수의 풍하중에 의한 거동특성을 유한요소해석기법을 사용하여 파악하였다. 개발한 유한요소모델은 속리의 정이품송을 토대고 구성하였다. 새로운 보강법으로 시도된 FRP wrap으로 보강된 나무에 대한 구조해석을 풍하중하에서 수행하였다. 그 결과 FRP wrapping에 의한 명확한 구조적 안정성의 증가를 보였으며 그 효과는 지반으로부터 1.2 m높이를 중심으로 wrapping을 한 모델에서 안정성증대효과가 극대화되는 것으로 나타났다. 본 연구의 해석결과가 향후 실물 실험을 통해 타당한 것으로 입증된다면, 수목 보강기법의 새로운 가이드라인을 제공하게 될 것으로 사료된다.

• Journal of Korean Society of Steel Construction
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• v.20 no.5
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• pp.675-681
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• 2008

This study introduced a new steel-jacketing method to retrofit RC columns. It also estimated the performance of steel-jacketed concrete cylinders. Twelve concrete cylinders were fabricated with varying steel jacket thicknesses of 1.0, 1.5, and 2.0 mm. Lateral confining pressure was applied with three clamps and the performance of plain concrete cylinders was compared with that of steel-jacketed cylinders. Steel jacket proved to be effective in increasing the strength of the cylinder. Finally, Li's constitutive model was compared with that of the experimentalresults. However, Li's model showed incongruity in Region II, which indicates the region after the yield of steel jackets. Therefore, the modified value of n was used for the region and the model showed a good agreement.