• 한국기계연구소 소보
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• 통권20호
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• pp.13-20
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• 1990

An algorithm is presented for 3-dimensional contour lines with a hidden line removal ~technique developed by T.L. Janssen(l). Contour line algorithm on any 3-dimensional plane cutting solid body is also shown. NUFIG(2) algorithm is adopted for searching contour lines. Test problems show well-established contour lines on the surface and also on the cutting plane of the structure.

• 한국결정학회지
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• 제14권2호
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• pp.93-104
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• 2003

The crystals of group-Ⅲ nitride semiconductors with wurtzite structure exhibit a strong polarity. Especially, GaN has characteristics of different growth rate, anisotropic electrical and optical properties due to the polarity. In this work, GaN epilayer was grown and the polarities of the crystals were observed by the chemical wet etching and SP-EFM. GaN thin films were deposited on c-plane A1₂O₃ substrate under the variations of growth conditions by HVPE such as the deposition temperature of the buffer layer, the deposition time, the ratio of Group-V and Ⅲ and the deposition temperature of the film. The adquate results were obtained under the conditions of 500℃, 90 seconds, 1333 and 1080℃, respectively. It is observed that the GaN layer grown without the buffer layer has N-polarity and the GaN layer grown on the buffer layer has Ga-polarity. Fine crystal single particles were grown on c-plane A1₂O₃ and SiO₂, layer. The external shape of the crystal shows ｛10-11｝｛10-10｝(000-1) planes as expected in the PBC theory and anisotropic behavior along c-axis is obvious. As a result of etching on each plane, (000-1) and ｛10-11｝planes were etched strongly due to the N-polarity and ｛10-10｝ plane was not affected due to the non-polarity. In the case of the crystal grown on c-plane A1₂O₃, two types of crystals were grown. They were hexagonal pyramidal-shape with ｛10-11｝plane and hexagonal prism with basal plane. The latter might be grown by twin plane reentrant edge (TPRE) growth.

• Earthquakes and Structures
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• 제6권5호
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• pp.515-537
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• 2014

Current seismic codes (e.g. the NTC08 Italian code and the EC8 European code) adopt a performance-based approach for both the design of new buildings and the assessment of existing ones. Different limit states are considered by verifying structural members as well as non structural elements and facilities which have generally been neglected in practice. The key role of non structural elements on building performance has been shown by recent earthquakes (e.g. L'Aquila 2009) where, due to the extensive damage suffered by infills, partitions and ceilings, a lot of private and public buildings became unusable with consequent significant socio-economic effects. Furthermore, the collapse of infill panels, particularly in the case of out-of-plane failure, represented a serious source of risk to life safety. This paper puts forward an infill model capable of accounting for the effects arising from prior in-plane damage on the out-of-plane capacity of infill panels. It permits an assessment of the seismic performance of existing RC buildings with reference to both structural and non structural elements, as well as of their mutual interaction. The model is applied to a building type with RC framed structure designed only to vertical loads and representative of typical Italian buildings. The influence of infill on building performance and the role of the out-of-plane response on structural response are also discussed.

• 한국전자파학회논문지
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• 제16권5호
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• pp.526-533
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• 2005

본 논문에서는 GPS 중심 주파수 1.575 GHz에서 마이크로스트립 안테나의 공진 길이 방향 양끝을 접거나 또는 네 방향 끝을 패치 아래로 모두 접어들이는 방법으로 선형 편파와 원형 편파 마이크로스트립 안테나의 소형화시키는 방법을 제시하고 설계, 제작하였다. 먼저 선형 편파의 경우, 마이크로스트립 안테나를 수직으로 내린 구조로써 안테나의 가시 길이를 $31.7\%(\varepsilon_r=1.06)$ 단축시켰으며, 이러한 접혀진 상태의 안테나를 다시 한번 안테나의 중심방향으로 접어 넣는 구조로 선형 편파 마이크로스트립 안테나를 구현하였다 그 결과 안테나의 가시 길이 단축율은 $73.6\%$이었으며 이득 5.12 dBd를 얻었다 -10 dB bandwidth는 $64MHz(4\%)$이고, E-plane과 H-plane의 HPBW는 각각 $151^{\circ},\;79.2^{\circ}$이었다. 또한 원형 편파의 경우, 네 방향 모두 선형 편파 안테나의 폴디드 구조를 적용시켰으며 접혀 넣어진 밑면의 면적 활용도를 높이기 위해 삼각형 구조로 설계하였다. 이때 안테나의 가시 면적 축소율은 $72.5\%$이었으며, 이득은 3.96 dBd이었다. -10 dB bandwidth는 $84 MHz(5.3\%)$, E-plane과 H-plane의 HPBW는 각각 $80.6^{\circ}$과 $82.1^{\circ}$이었다 이 결과들로부터, 선형 편파와 원형 편파의 폴디드 마이크로스트립 안테나가 일반적인 마이크로스트립 패치 안테나의 특성을 유지하면서 소형화되었기 때문에 본 논문에서 제안된 구조가 소형화에 적합함을 확인할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.291-296
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• 2007

To analyze accurately the free vibration of a structure by using the finite element method (FEM), we model the structure as a numerical model with many degrees-of-freedom. However the FEM needs much computation time and storage in this case. The authors developed the finite element-transfer stiffness coefficient method (FE-TSCM) for overcoming the drawback of the FEM. In this paper, the authors apply the FE-TSCM to the in-plane free vibration analysis of plates with various shapes. Two numerical examples, a rectangular plate and a triangular plate, are used to compare the results of the FE-TSCM and the FEM. Through the numerical calculation, we confirm that the FE-TSCM can be applied to the plates with various shapes and is effective to in-plane free vibration analysis of plates.

• 한국강구조학회 논문집
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• 제24권2호
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• pp.137-147
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• 2012

본 연구는 L형, I형 실험체에 강판 콘크리트 구조와 철근콘크리트 구조를 적용하여 이질접합부를 만들고, 실험체에 반복하중을 파괴 시 까지 가력하여 면외 휨 내력 및 면내 전단 내력을 평가하고 구조특성을 검토하기 위해서 실험연구를 수행하였다.본 연구에서 면외 휨 성능실험은 접합부에서 정착부 수직철근이 인발되면서 파괴되었고, 면내 전단성능실험은 기초부에서의 휨 균열이 발생하여 파괴되었으며, 이론식과의 비교결과 최대 내력이 실험값/이론값의 결과가 면외 휨성능실험은 96%, 면내 전단성능실험은 82%의 값을 나타내었다.

• 한국해양공학회지
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• 제31권4호
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• pp.299-307
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• 2017

The design of the mooring line to maintain the position of an offshore structure in rough marine environments is recognized as a very important consideration. Conventional fatigue evaluation of a mooring line was performed by considering the tensile force acting on the mooring line, but the mooring line broke after 238 days in the girassol area even though the expected fatigue life was expected to be longer. The causes of this event are known to be due to OPB/IPB (out-of-plane bending/in-plane bending) caused by chain link friction due to the excessive tensile strength of the mooring line. In this study, three models with different boundary conditions were proposed for fatigue analysis of a mooring line considering OPB/IPB. Interlink stiffness was calculated by nonlinear structure analysis and a stress concentration factor was derived. In addition, the sensitivity of interlink stiffness according to the magnitude of tensile force, large deformation effect, and coefficient of friction was analyzed, and the effect of critical elastic slip and bending moment calculation position on interlink stiffness was confirmed.

• 한국CDE학회논문집
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• 제21권1호
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• pp.90-98
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• 2016

When ships and offshore plants are flooded or the floating crane is equipped with a heavy object, these floating structures are excessively inclined. In this case, immersion, heel, and trim affecting the hydrostatic restoration performance are very large and are coupled each other. In this paper, in order to calculate a static equilibrium position of floating structures with excessive inclination, the nonlinear governing equations were constructed by sequential linearization. In the governing equation, the immersion, heel, and trim are fully coupled, and the equations are represented using a plane area, a primary moment, and a moment of inertia of the water plane area. Therefore, it is possible to calculate the additional factor related the water plane area for estimating stability. Position and orientation of the floating structure are obtained by iterative calculation. The calculated results are compared with the previous studies in the aspect to the performance and the accuracy.

• 한국조경학회지
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• 제19권3호
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• pp.16-26
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• 1991

The traditional housing of Cheju Island has been steadily researched, but from the point of an environmental view which has been neglectly treated all the while, the formative process of the housing and its relationship to the structure of a village are studied, so the writer summarized the relation to the housing type. To study the peculiarity of the physical space, a type of a way, and element of the spatial structure, by stage and a type of the arrangement of the residential space are researched and analyzed, and to understand the plane peculiarity, the distribution of the plane type has been studied. In consequence, the housing and the structure and the form of the village have an organic relation each other and have been made under a very diverse and mixed background, we can find. Especially, the element of the natural environment acts as an important element which decides the type of life and the residential type. The arrangement of buildings is gradually free from the traditional type, but a traditional type of "Three-Room House" is kept well in spite of a change of the plane type.

• 한국농촌건축학회논문집
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• 제9권2호
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• pp.21-28
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• 2007

This thesis analyzed the uniqueness of a toilet plane structure, centering on a case of Beautiful Public Toilet Construction Project under a project by Chungcheongnam-do and drew a conclusion as followings. Most of public toilets, constructed under a project by Chungcheongnam-do, were located in remains, tourist resorts, parks, and the outskirts of traditional markets. They were constructed at the selected location within an easy access of most user and plane structure was also designed so that the persons, in charge of management and maintenance, and the users could use them without difficulty. But some public toilets didn't establish the handicaps' toilet or made them difficult to sue due to location or size. The plane structure style was various such as a rectangular, stream line, or circle in accordance with location or building size. A circle-styled toilet offered a good view but didn't offer a good access or an effective space for users. In addition, when a handicapped person enters a toilet, he or she has to enter or go out of it through a sliding dor. So a constructor has to make progress of a work in accordance with this point.