• 한국재료학회지
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• 제9권3호
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• pp.251-256
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• 1999

대전력을 사용하는 제강공장의 L/F설비에서 발생되는 강자계를 효율적으로 차폐하기 위하여 L/F주위의 자기장 분포를 유한해석법을 이용한 사용해석도구인 ANSYS 5.3 3차원 자기장해석기를 통해 해석하고 그 결과를 평판형태의 차폐체에 적용시키고자 하였다. 분석결과, L1 및 L2가 각각 2.7 및 2.9m 이려 높이가 3.5m인 2중차폐체(1차측 차폐: 1mmt의 전기강판, 2차측차폐: 1mmt의 Fe-Ni alloy sheet)를 설치하는 거싱 최적의 처폐방안으로 도출되었다.

• Applied Microscopy
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• 제48권4호
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• pp.128-129
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• 2018

Soft ferromagnetic materials are utilized for various electromagnetic devices such as magnetic recording heads and magnetic shielding. In situ observation of magnetic microstructures and domain wall motions are prerequisite for understanding and improving their magnetic properties. In this work, by the Fresnel (out-of-focus) method of Lorentz microscopy, we observe the domain wall motions of polycrystalline Ni/Ti thin film layers triggered by single-shot laser pulse. Random motions of domain walls were visualized at every single pulse.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.608-611
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• 2004

As the use of various electronic equipments has been increased recently according to industrialization and information network establishment, concern about electromagnetic wave exposed environment has also been increased. Therefore, this study aims to verify electromagnetic wave absorbing effects of inorganic paint that is made of carbon, electro-conductive materials with regard to its physical characteristics, its electromagnetic wave absorbing rate through a mock-up test for proving its effects in the indoor condition. The results are as follows: The results of running tests on electromagnetic wave absorbing inorganic paints for checking their requirements as painting material such as adherence degree, resistance to fine crack, resistance to washing, alkali-resistance, discoloration-resistance, etc. show that inorganic paints have the physical characteristics meeting the requirements for painting materials. In addition, it shows that the electromagnetic wave absorbing effect, in line with the number of paintings and the thickness of paintings, secures $75\~89\%$ of efficiency. And the mock-up test shows that the electromagnetic wave absorbing effect inside building is directly proportional to the distance from the source of electromagnetic wave such as electronic equipments.

• 대한기계학회논문집A
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• 제41권9호
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• pp.887-895
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• 2017

본 논문에서는 일반적으로 문틀과 문짝을 연결하여 개폐시 작동하는 부품인 힌지의 가속수명시험법에 대한 연구이다. 힌지는 사용하는 용도에 따라 구조와 고장모드가 상이하며 본 연구에서는 전자파 차폐시설에 사용되는 개폐장치 구성품 중 하나인 힌지에 대해서 고장모드를 분석하고 현장작동조건에서의 이론적 검증과 시험장비에 대한 타당성을 분석하였다. 그리고 형상모수와 가속지수의 추정을 통한 특성수명 예측을 위한 가속수명시험법을 설계하였다.

• Journal of Welding and Joining
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• 제30권5호
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• pp.46-50
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• 2012

This study was carried out to investigate the effect of welding parameters such as shielding gas compositions welding voltage and welding current on the pore formation in the weld beads of galvanized steel pipes produced with gas metal arc welding. The porosity was evaluated and rated by metallography and radiographic test in terms of weight percentage, number and distribution of pores in weld beads. The porosity increased with increasing welding voltage and current, in which Ar gas produced the most porosity while $Ar+5%O_2$ generated the least porosity. It was found that the porosity could be reduced by selection of the proper gas mixture composition such as $Ar+5%O_2$ and $Ar+10%CO_2$ and by using current (130~150A) and voltage(16~20V).

• 한국기계가공학회지
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• 제19권10호
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• pp.59-67
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• 2020

Polycarbonate thermoplastic composite materials are anisotropic and exhibit physical properties in the longitudinal direction. Therefore, the physical properties depend on the type and direction of reinforcements. The thermal conductivity, electrical conductivity, and resin impregnation can be controlled by adding carbon nanotubes to polycarbonate resin. However, the carbon fiber used as a reinforcing material is expensive, interfacial adhesion issues occur, and simulation values are different from actual values, making it difficult to perform mathematical analysis. However, carbon nanotubes have advantages such as light weight, rigidity, impact resistance, and reduced number of parts compared to metals. Due to these advantages, it has been applied to various products to reduce weight, improve corrosion resistance, and increase impact durability. As the content of carbon nanotubes or carbon fibers increases, the mechanical properties and antistatic and electromagnetic shielding performance improve. It is expected that the amount of carbon nanotubes or carbon fibers can be optimized and applied to various industrial products.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3506-3513
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• 2023

In this paper, we demonstrate the neutron attenuation of dry cask shielding materials using the S670e helium-4 detector manufactured by Arktis Radiation Ltd. In particular, two materials expected to be applied to the TN-32 dry cask manufactured by ORANO Korea and KORAD-21 by the Korea Radioactive Waste Agency (KORAD) were utilized. The measured neutron attenuation was compared with our Monte Carlo N-Particle Transport simulation results, and the difference is given as the root mean square (RMS). For the fast neutron case, a rapid decline in neutron counts was observed as a function of increasing material thickness, exhibiting an exponential relationship. The discrepancy between the experimentally acquired data and simulation results for the fast neutron was maintained within a 2.3% RMS. In contrast, the observed thermal neutron count demonstrated an initial rise, attained a maximum value, and exhibited an exponential decline as a function of increasing thickness. In particular, the discrepancy between the measured and simulated peak locations for thermal neutrons displayed an RMS deviation of approximately 17.3-22.4%. Finally, the results suggest that a minimum thickness of 5 cm for Li-6 is necessary to achieve a sufficiently significant cross-section, effectively capturing incoming thermal neutrons within the dry cask.

• 분석과학
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• 제13권4호
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• pp.474-483
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• 2000

사용후핵연료에 함유되어 있는 핵분열생성물을 분석하기 위하여 여러 원소를 동시에 분석할 수 있고, 분석감도가 커서 시료의 방사능과 폐기물의 양을 감소시킬 수 있는 유도 결합 플라스마 원자방출분광기/차폐 시스템을 구성하였다. 방사성 물질이 직접 접촉되는 플라스마 들뜸원과 시료용액 도입부를 스테인리스 스틸 재질의 글로브박스 내부에 설치하였으며, 고주파 들뜸전원, 분광기, 검출기 그리고 전기, 전자 및 아르곤 가스 공급 제어장치는 외부에 설치하였다. 분석능과 방사선 안전의 관점에서 시스템의 특성을 검증하였으며, 사용후핵연료 용해용액과 원자력발전소의 일차냉각수를 대상으로 핵분열생성물과 방사성 부식생성물 분석에 대한 적용성을 평가한 결과 $0.01-0.1mgL^{-1}$ 농도범위에서 상대표준편차는 5% 이하였다.

• 한국산학기술학회논문지
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• 제18권2호
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• pp.95-101
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• 2017

본 논문에서는 복합재료로 만들기 위한 전처리 단계에서 수행한 사이징 제거 상태를 영상처리 알고리즘을 적용하여 수치적으로 나타내었고, 전자파 차폐 성능을 높이기 위해서 건식 공정 방식으로 니켈도금 탄소섬유를 제작하였다. 탄소섬유 제조에서 폴리머 종류로 감싸져 나온 사이징은 건식 코팅을 위해서는 제거해야 한다. 사이징이 제거된 상태를 주사 전자현미경(scanning electron microscope, SEM)으로 촬영한 이미지에서 탄소 섬유의 규칙적인 패턴, 즉 상관성을 구함으로써 수치적인 값으로 나타낼 수 있다. 사이징의 제거 방식은 용액, 압축 공기와 용액과 압축공기(하이브리드)로 제거한 SEM 영상에 대하여 제안된 방법을 적용한 결과 하이브리드 방식이 우수함을 확인 할 수 있었다. 그리고 사이징이 제거된 스프레딩 탄소 섬유 롤을 롤투롤 스퍼터 방식으로 니켈도금 탄소 섬유를 제작할 수 있었다. 제작된 30um, 40um과 100um 니켈코팅 탄소섬유에 대해서 전자파 차폐 성능을 측정하였다. 한국산업기술시험원에서 100um 니켈코팅 탄소섬유의 전자파 차폐 성능을 평가한 결과 최저 66.7(dB)에서 최고 73.2(dB)의 전자파 차폐 성능을 보였다. 이것은 구리의 전자파 차폐율과 유사하여 EV/HEV자동차의 케이블로 사용될 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.628-632
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• 2000

In the recent day, shielding can was made of permalloy materials for automobile display instrument. The good roundness has an effect on magnetic property such as the low coercivity and the high permeability. But the products having the roundness is transformed by the heat treatment, the sending to the company and the assembly process. So for the stiffness of the edge, it is necessary for hemming process to be added in the deep drawing process. And it has the good appearance to create a smooth edge rather than a razor edge with urr. In this paper, it is controlled to get the best hemming product by the Pre-hemming angle($105^{\circ}$, $120^{\circ}$, $135^{\circ}$). And Possible process and tool design modification, which may lead to quality improvement in hemming were tested experimentally and using FEM. The commercial finite element program PAM-STAMPTM was used to simulate the pre-hemming process and hemming process, and the predictions were compared with experimental results according to the pre-hemming angle.