• 대한수학회지
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• 제32권2호
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• pp.351-361
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• 1995

Let M be a complete open Riemannian manifold. When the sectional curvature $K_M$ of M is nonpositive, Gromov has defined, in his lectures [3], the ideal boundary of M, and used it to study the geometric structure of M. In a Hadamard manifold, a simply connected manifold with nonpositive sectional curvature, a point at infinity can be defined as an equivalence class of rays. He proved many interesting theorems using this definition of ideal boundary and the so-called Tit's metric on it. He also suggested a counterpart to this for nonnegative curvature case. This idea has been taken up by Kasue to study the structure of complete open manifolds with asympttically nonnegative curvature [14]. Motivated by these works, we will define an idela boundary of a general noncompact manifold M, and study its structure.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.85-101
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• 2020

The optimal parameters for the fluid-structure interaction analysis using the Smoothed Particle Hydrodynamics (SPH) for fluids and finite elements for structures, respectively, are explored, and the effectiveness of the simulations with those parameters is validated by solving several open surface fluid problems. For the optimization of the Equation of State (EOS) and the simulation parameters such as the time step, initial particle spacing, and smoothing length factor, a dam-break problem and deflection of an elastic plate is selected, and the least squares analysis is performed on the simulation results. With the optimal values of the pivotal parameters, the accuracy of the simulation is validated by calculating the exerted force on a moving solid column in the open surface fluid. Overall, the SPH-FEM coupled simulation is very effective to calculate the fluid-structure interaction. However, the relevant parameters should be carefully selected to obtain accurate results.

• 교육녹색환경연구
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• 제3권1호
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• pp.15-23
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• 2003

Focusing on both the form of open classroom and that of independent one which have been most planned and being built, this study was designed to see if the educational environment of their inner space, structure, and facilities gives a proper support to classroom activities during the various classes based on open education. Selecting representative teaching methods in elementary school, such as open simultaneous learning, learning through a medium, learning in the corner, subject learning, team teaching and learning hardening basics, this study surveyed problems and improvements using literature works, questionnaires, observing, and interviews. Through the study on learning space for open education, it has been known that the form of independent classroom fits into one classroom learning and open classroom into small group learning and individual learning, and that the form of open classroom connecting open space with a classroom are more desirable when there is change from large to small group.

• 한국조경학회지
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• 제26권4호
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• pp.135-143
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• 1999

This study is about the pattern of spatial structures of major university campuses in Korea. The pattern is composed of buildings, circulation, and open space within the campus. It is physical structural system which makes campus more educational environment as well as new academic landscape. The pattern is checked on the basis of existing sub-patterns of eleven universities with base data by using computer program, Autocad and Landcadd. The result is that most of campus spatial structures consists of simple and unified grid pattern. Basic educational facilities are at the center of the whole structure as well. Some universities are located in suburb and have large site which makes it more open space oriented pattern, more various exterior space and more specific circulation system. So the campus patterns of recently built is more diverse and has more design components. In most cases, campus does not have strong spatial coherence among its buildings, circulation, and open space. It is important to develop Korean formal campus spatial structure which is intrinsic to its site and is proper to its academic plan. Campus spatial structure should be formulated to embrace diverse demands of university and to accumulate unique university landscape.

• 융합보안논문지
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• 제20권2호
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• pp.37-52
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• 2020

최근 우리나라를 비롯한 EU, 영국 등은 금융구조 개혁 및 금융소비자의 편의성 제고를 위하여 금융회사가 보유하고 있는 금융정보를 핀테크기업에게 개방하는 오픈뱅킹을 적극 추진하고 있다. 향후 오픈뱅킹이 점차 활성화될수록 오픈뱅킹 제공기관의 안정성 확보 및 이용자 보호의 중요성은 더욱 커질 것이다. 특히 우리나라는 전자금융거래의 안정성과 신뢰성 확보를 위하여 2007년부터 시행해 온 전자금융거래법이 있지만, 오픈뱅킹 제공기관에게 적용하기 어려운 한계가 있어 오픈뱅킹에 대한 보안사고 예방 및 이용자 보호가 취약해질 위험성이 있다. 따라서 본 논문에서는 오픈뱅킹에 관한 외국의 규제를 살펴보고, 국내 오픈뱅킹의 안정성 강화 및 이용자 보호를 위한 규제 개선 방안을 제시해 본다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.475-477
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• 1997

A new open structure of the bird-cage RF coil is proposed. By applying in-phase or out-of-phase voltage to the two terminals of the open bird-cage RF coil, desirable level of RF field uniformity has been achieved. Theoretical resonance frequencies of the RF coil has been obtained and compared with experimental ones. The quality factor of the open bird-cage RF coil has been found to be comparable to the one of the conventional RF coil.

• 복식
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• 제38권
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• pp.179-191
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• 1998

On this thesis, the focus is that studying costumes which have been affected by deconstructionism that is based on chaos and fractal the-ory. Chaos and fractal theory is accepted as a new paradigm for open world which is changing very vast and fast. And this theory is needed for artists and designers who should have spacetime conciousness and open mind and attitude towark open world. In the results, various costume typess of deconstructionism have been shown by fashion designers and artists' works. Thoes are as follows; 1. normal relationship of costume changes to abnormal relationship 2. three-dimentional structure of costume changes to two-dimentional structure. 3. open to materials and techniques. 4. separated costume parts reconstruct as ambiguous whole on function. 5. body absence and accessorizing.

• 한국해양환경ㆍ에너지학회지
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• 제20권2호
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• pp.63-75
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• 2017

해양환경에서 파랑-구조물 상호작용의 정확한 예측은 극한 환경조건에 노출 된 고정식 및 부유식 해양구조물의 안전성과 설계비용 효율성에 있어서 중요하다. 본 연구에서는 규칙파 와 원형 기둥의 파랑-구조물 상호작용을 해석하였다. 3차원 이상유동(two-phase flow)을 해석하기 위해 오픈소스 전산유체역학 라이브러리인 OpenFOAM을 사용하였다. 수치파랑수조에서 파를 생성 및 흡수하기 위해 소스항을 이용한 relaxation method를 적용하였다. 수치기법을 검증하기 위해 심해조건에서 생성된 2차 stokes 파형은 이론적인 해와 비교하였다. 검증과정을 통해 파장과 진폭에 대한 길이 및 높이 방향의 격자크기를 정하였다. 원형 기둥에 작용하는 파랑 하중과 wave run-up을 계산하고 기존의 실험 데이터와 비교하였다.

• Composites Research
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• 제27권2호
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• pp.77-81
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• 2014

본 연구에서는 전기체 복합재가 적용되어 설계된 소형 항공기의 손상 평가 및 유지 보수 연구를 수행하였다. 본 연구에서 개발 중인 항공기의 스킨 부위는 샌드위치 구조가 적용되었다. 본 연구에서는 노멕스 허니컴코어와 카본 면재가 적용된 샌드위치 복합재 구조에 대해 구멍 손상 이후의 잔류 강도 평가에 대한 연구를 수행하였다. 4점 굽힘 시험을 통해 시편의 굽힘 강도를 확인하고, 시편에 손상을 모사하기 위하여 시편의 중앙 부위에 구멍 손상을 가하였다. 손상된 시편을 손상 전 시편과 동일한 시험을 통해 손상 전의 강도와 비교하였다. 또한 손상된 복합재 구조는 손상 부위 제거 후 패치 수리 기법을 적용하고 손상된 시편과 보수된 시편의 굽힘 강도 시험결과를 비교하였다. 샌드위치 복합재 구조 시편의 유지 보수 후 굽힘 강도 시험 결과 손상 전 시편의 강도와 비교하여 강도의 95%까지 회복되는 것으로 분석되었다.

• Structural Engineering and Mechanics
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• 제76권2호
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• pp.269-278
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• 2020

In this paper, the mechanical characteristics of the open type hyperbolic-parabolic membrane structure under wind load were investigated. First, the numerical simulation of a typical plane membrane structure was performed based on the Large-Eddy Simulation method. The accuracy of the simulation method was validated by the corresponding wind tunnel test results. Then, the wind load shape coefficients of open type hyperbolic-parabolic membrane structures are obtained from the series of numerical calculations and compared with the recommended values in the "Technical Specification for Membrane Structures (CECS 158: 2015). Finally, the influences of the wind directions and wind speeds on the mean wind pressure distribution of open type hyperbolic-parabolic membrane structures were investigated. This study aims to gain a better understanding of the wind-induced response for this type of structure and be useful to engineers and researchers.