• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.41-41
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• 2001

포항가속기의 초고진공 세정기술은 초고진공 영역에서의 기체방출을 최소화하기 위한 것으로 발생한 오염원을 추적하여 큰 오염원 부터 시작하여 단계적으로 진행해 미세한 오염원 을 제거해 나가는 방법을 적용하고 있다. 이러한 극청정한 진공표면을 얻기 위해서는 표면과 오염물질 사이의 결합에너지를 극복해야 한다. 오염물 제거 방법으로는 물리.전기.화학적인 방법을 모두 적용하며 그리스 및 절삭유를 비롯해 흡착된 탄화수소와 불순물 성분 또는 산소나 황과 같은 반응성 원소와의 화합물 등을 효과적으로 제거한다. 또한, 세정 과정 에서 생성될 수 있는 수소, 불규칙한 산화물, 질화물, 염화물, 그리고 탄수화물을 최소화하여 초고진공 영역에 도달할 수 있는 방법을 제공한다. 본 논문에서는 포항가속기 연구소의 초고진공 환경을 확보하기 위한 화학세정 설비 및 응용기술, 주요 진공 구성재료의 표면 분석 결과를 소개하고자 한다.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.366-368
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• 2007

하이브리드 차량은 기존의 화석연료를 사용하는 엔진과 배터리, 초고용량 커패시터로부터 전원을 공급받는 전동기를 직 병렬 구조로 연결하여 연비를 개선하기 위해 개발되었다. 이를 위하여 가속 시 배터리와 초고용량 커패시터의 방전으로부터 전원을 공급받고, 감속 시 회생제동을 통해 다시 충전을 반복한다. 최근 배터리와 초고용량 커패시터의 용량 및 출력의 장단점을 상호 보완하고자 이중 보조 동력원에 대한 연구가 활발히 진행되고 있다. 본 논문에서는 배터리와 초고용량 커패시터의 내부 저항을 고려하여 병렬 사용하는 이중 보조 동력원 시스템에 대하여 각각의 충전용량(SOC)에 따른 운전전략을 개발하고자 한다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.345-346
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• 2015

본 논문에서는 재난상황발생 시 신속하고 효율적인 재난대응에 실패하면 다수의 인명피해를 야기할 수 있는 초고층 건축물의 재난시나리오 기반 피난계획수립에 대한 연구과정을 제시하고 발전방향을 제안하였다. 초고층 건축물의 피난계획수립을 위해서 초고층 건축물에서 발생 가능한 재난시나리오를 자연재난, 인적재난, 전쟁 또는 테러재난, 건물시설관계재난인 4가지 유형으로 분류하고 이를 프로토콜화하여 건축물의 피난관리시설과 자원을 고려한 피난계획을 작성하고 이를 피난시뮬레이션을 통해서 검토하고 보완하는 연구를 진행하여 최종적으로 효율적인 피난계획서를 수립하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.228-229
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• 2020

최근 딥러닝 기술은 여러 컴퓨터 비전 응용 분야에서 많이 쓰이고 있다. 물체 인식, 분류 및 영상 생성 등을 예로 들 수 있다. 특히 초고해상도 변환 문제에서 최근 딥러닝을 사용하면서 큰 성능 개선을 얻고 있다. Fast super-resolution convolutional neural network (FSRCNN)은 딥러닝 기반 초고해상도 알고리즘으로 잘 알려져 있으며, 여러 개의 convolutional layer로 추출한 저 해상도의 입력 특징을 활용하여 deconvolutional layer에서 초고해상도의 영상을 출력하는 알고리즘이다. 본 논문에서는 병렬 연산 효율성을 고려한 FPGA 기반 convolutional neural networks 가속기를 제안한다. 특히 deconvolutional layer를 convolutional layer로 변환하는 방법을 통해서 에너지 효율적인 가속기를 설계했다. 또한 제안한 방법은 FPGA 리소스를 고려하여 FSRCNN의 구조를 변형한 Optimal-FSRCNN을 제안한다. 사용하는 곱셈기의 개수를 FSRCNN 대비 2.4 배 압축하였고, 초고해상도 변환 성능을 평가하는 지표인 PSNR은 FSRCNN과 비슷한 성능을 내고 있다. 이를 통해서 FPGA 에 최적화된 네트워크를 구현하여 FHD 입력 영상을 UHD 영상으로 출력하는 실시간 영상처리 기술을 개발했다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2487-2496
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• 2013

The main objective of this study is to develop the application system of building code in super-tall building design. In order to improve the design company's qualification in the specialized building project such as super-tall, developing the reasonable application of domestic building code system is one of essential factors. This study show the unique environment required in the super-tall design process and compare the regulation system in domestic building code and international building code, mostly US. By analyzing the building codes of Busan Lotte Tower, this study suggest the addition or modification of building code application for the similar super-tall building design projects.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.349-356
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• 2011

In this paper, the optimal diagrid angle of atypical tall buildings has been found using diagrid optimization technique which is based on parametric algorithm. A diagrid is a diagonal grid which can be seen among atypical tall buildings and structures which effectively resist horizontal and vertical direction loads. Therefore, it is also the objective of this studyto find the maximum stiffness of atypical tall buildings by optimizing diagrid angle. Moreover, this study touches on both cylindrical and tapered off cylindrical structures, as shown in the examples to check the compatibility of optimum diagrid angle, which effectively resists horizontal deformation on top by optimization algorithm.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.387-391
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• 2007

A proper selection of formwork greatly affects project success in tall building construction. The tall building construction, however, has not been selected properly using the characteristics by formwork and demands the comprehensive consideration of cost, duration, quality, safety, and environment. Therefore, this study compares and analyzes the application by formwork of five aspects. In order to perform an analysis, the questionnaire was performed to research the priority order of management as determining formwork and application by formwork of tall building construction engineers. This study is expected to help reasonable selection of formwork.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.2
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• pp.51-58
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• 2008

This study is to investigate the ultimate shear load of prestressed girder made of Ultra High Performance Fiber Reinforced Concrete (UHPFRC). Nine girders were tested until failure in shear. An analytical model to predict the ultimate shear load was formulated based on the Two Bounds Theory. A fiber reinforcing model was constituted based on the random assumption of steel fiber uniform distribution. The predicted values were compared with the conventional predictions and the test results. The proposed equations for computing the ultimate shear strength can be used for the ultimate failure status analysis, which could also be utilized for numerical limit analysis of prestressed UHPFRC girder. The established fiber reinforcing theoretical model can also be a reference for micro-mechanics analysis of UHPFRC.

• Journal of the Korea Concrete Institute
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• v.26 no.5
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• pp.599-606
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• 2014

Since progressive collapse of tall buildings can cause enormous damage, it should be considered during the design phase of tall buildings. The progressive collapse analysis of tall buildings using finite element methods is almost impossible due to the vast amount of computing time. In this paper, applied element method was evaluated as an alternative to the finite element method. Reduced DOFs modeling technique was proposed to enable the progressive collapse analysis of tall buildings. The reduced DOFs model include only the part which is subjected to direct damage from blast load and the structural properties such as mass, transferred load and stiffness of excluded parts are accumulated into the top story of the reduced DOFs model. The proposed modeling technique was applied to the progressive collapse analysis of 20-story RC building using three collapse scenarios. The reduced DOFs model showed similar collapse behavior to the whole model while the computing time was reduced by 30%. The proposed modeling technique can be utilized in the progressive collapse analysis of tall buildings due to abnormal loads.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.190-199
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• 2020

Globally, more super-tall buildings tend to be constructed competitively in the social and economic foundations. In the circumstance, this study is aimed at establishing a paradigm of super-tall buildings in terms of their various forms. Symbolizing a city or state, super-tall buildings not only are used as resources of tourism, but play an important role as a characteristic landmark. Therefore, it is necessary to find a curved form for a futuristic perspective. The purpose of this study is to infer the convergence relativity of curved forms among complex and diverse unstructured construction forms. This study used as subjects 50 super-tall buildings among the ranking data selected Council on Tall Buildings and Urban Habitat (CTBUH) in order for the basis of constructability related to actual design, rather than the way of recognizing a formative type, in the classification of curved forms into regularized surfaces, developable surfaces, and double-curved surfaces. The results of this study are presented as follows. This classification can be used as a fundamental material which is reasonably involved in the design process pursuing diverse curved surfaces in terms of design of tall buildings.