• 한국환경농학회지
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• 제41권3호
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• pp.217-221
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• 2022

BACKGROUND: Gotjawal forest on Jeju Island is characterized by uneven topography that developed as a result of freezing-thawing weathering process and irregular substrates caused by numerous lava-flow collapses. Sanyang Gotjawal, located in southwest of Jeju Island, is a well-developed forest with a long history. In addition to photographs, there is a need for a good way to describe the unique features of Gotjawal, including its geology and vegetation. METHODS AND RESULTS: We illustrated the area's natural features using Clip Studio Paint 1.12.0. To reveal its complexity, we separated the vegetation and geological features in the illustrations. CONCLUSION(S): We drew a cross-section of Gotjawal's unique layers, including lava flows. In addition to an eco-geological approach, we described the dominant vegetation and geological characteristics of the three forest layers (trees, shrubs, and herbs) in Gotjawal.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.170-175
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• 2019

Displacement cross-sections for an advanced assessment of radiation damage rates were obtained for a number of materials using the arc-dpa model at neutron incident energies from $10^{-5}eV$ to 10 GeV. Evaluated data files, CEM03 and ECIS codes, and an approximate approach were applied for the calculation of recoil energy distributions in neutron induced reactions. Three sets of displacement cross-sections based on the use of low-energy data from JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u were prepared. Files contain also cross-sections calculated using the standard NRT model. Special efforts were made to estimate the uncertainty of obtained displacement cross-sections.

• 건축역사연구
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• 제26권2호
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• pp.7-14
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• 2017

Rafter is a member for roof and plays a role in protecting shaft members under rafter such as pillar, beam and girder from natural environment and to fix by supporting finished materials of roof. It is common in the Korean architecture that rafter cross-section is paired with circular form and Buyeon cross-section is paired with the square shape. However, while there are not many, some architectures have rafter end header in the square shape. The aim of this study is to examine the square shape cases of rafter end header with special reference to stone structure. As a result, among stone structure related to Bangyeon, the majority case is seen at Palgakwondang type Seungtap. It was shown in the Seungtap of monk of Gusanseonmun school in the later Unified Silla to the early Goryeo period that succeeded Seodang Jijang.

• 한국전산구조공학회논문집
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• 제12권4호
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• pp.563-571
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• 1999

변단 면과 다양한 경계조건을 갖는 보와 타워구조물의 제1모드에서의 고유진동수를 구하는 정확한 해는 1974년에 Kim에 의해 발표되었다. 최근 이 방법은 복합재료 적층 판을 포함하는 2차원 문제의 제 1모드 진동해석에 확장되었으며, 다양한 경계조건과 불규칙 단면을 갖는 판에 매우 효과적이다. 이 논문에서는 변단 면과 경계조건에 따른 특별직교 이방성 판에 대한, Kim에 의해 개발된 간편한 진동해석 방법의 응용결과가 주어진다. 또한 집중하중들에 대한 영향이 연구되었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.311-315
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• 2008

Currently, in automobile industry. the efforts to reduce the manufacturing cost by changing the process of manufacturing are continually performed. In this paper, we proposed a new manufacturing process, the roll bending of a ring plate of automotive fuel tank instead of conventional press blanking process to reduce material loss and manufacturing cost. Finite element analysis was used to optimize the roll bending process to assure rectangular cross-section of the ring plate. Also, spring-back analysis after the roll bending was performed and dimension of the bending die considering spring-back was analyzed. Finally, we verified a possibility for realization of the proposed method shape with prototypes.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.555-558
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• 2009

본 논문은 상대방으로부터 탐지를 최소화시키는 스텔스 기술을 분석하고, 대부분의 레이더 반사 단면적 감소는 형상화로부터 기인되며, 특별한 부위에는 RAM을 이용하여 최소화 시키는 것을 확인하였다. 따라서 RF 스텔스를 위한 밀리미터파 대역의 레이더 반사 단면적을 최소화시키는 측면에서 94 GHz에서 전파흡수량 17 dB로 98 %를 흡수하는 RAM을 설계 및 제작하였다. 결과적으로 개발된 RAM을 플랫폼에 적용시 상대방으로부터 레이더 탐지거리를 62 % 축소시키는 효과를 얻을 수 있다.

• Transactions on Electrical and Electronic Materials
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• 제2권1호
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• pp.7-11
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• 2001

We measured the electron transport coefficients, the electron drift velocity, W, and the longitudinal diffusion coefficient, $D_{L}$, over the E/N range from 0.03 to 100 Td and gas pressure range from 0.133 to 122 kPa in the 0.526% and 5.05% $C_{3}F_{8}$-Ar mixtures by the double shutter drift tube with variable drift distance. And we calculated these electron transport coefficients by using multi-term approximation of Boltzmann equation analysis. We determined the electron collision cross sections set for $C_{3}F_{8}$ molecule by the comparison of measurement and calculation. Our special attention in the present study was focused upon the inelastic collision cross sections of the $C_{3}F_{8}$ molecule.

• 한국전기전자재료학회논문지
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• 제19권3호
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• pp.301-306
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• 2006

The electron drift velocity W and the product of the longitudinal diffusion coefficient and the gas number density $ND_{L}$ in the $0.525\;\%$ and $5.05\;\%$ $C_{3}F_8-Ar$ mixtures were measured by using the double shutter drift tube with variable drift distance over the E/N range from 0.03 to 100 Td and gas pressure range from 1 to 915 torr. And we determined the electron collision cross sections set for the $C_{3}F_8$ molecule by STEP 1 of electron swarm method using a multi-term Boltzmann equation analysis. Our special attention in the present study was focused upon the vibrational excitation and new excitations cross sections of the $C_{3}F_8$ molecule.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.93-96
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• 2000

The theory of non-prismatic folded plate structures was reported by the senior author in 1965 and 1966. Fiber reinforced composite materials are strong in tension. The structural element for such tension force is very thin and weak against bending because of small bending stiffnesses. Naturally, the box type section is considered as the optimum structural configuration because of its high bending stiffnesses. Such structures can be effectively analyzed by the folded plate theory with relative ease. The "hollow" bending member with uniform cross-section can be treated as prismatic folded plates which is a special case of the non-prismatic folded plates. Tn this paper, the result of analysis of a folded plates with one box type uniform cross-section is presented. Each plate is made of composite laminates with fiber orientation of [ABBCAAB]$_r$, with A=-B=$45^{\circ}$, and C=$90^{\circ}$. The influence of the span to depth ratio is also studied. When this ratio is 5, the difference between the results of folded plate theory and beam theory is 1.66%. is 1.66%.

• 한국공간구조학회논문집
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• 제19권2호
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• pp.35-42
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• 2019

The purpose of this paper is to evaluate the structural performance of joints between modules with steel plate press forming type non-symmetric cross section. The main experimental variables are direction of load, whether vertical bolts are fastened, and whether the concrete inside the column is filled. A total of three experiments were performed for each variable. Experimental results show that the behavior of the joints dominated by the local buckling deformation of the upper and lower beam flanges of the module joints, and the final failure was the fracture of the column-beam welds. In case of short side direction, it is possible to secure the performance of intermediate moment frame (0.02 rad). In case of long side direction, it is evaluated that the performance of special moment frame (0.04 rad) is secured regardless of whether or not concrete is infilled in the column.