• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 초전도 자성체
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• pp.79-82
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• 2002

Induction heating is widely used in today's industry, in operations such as metal hardening, preheating for forging operations, melting or cooking. In this paper, it was presented the magneto-thermal analysis of an induction heating jar(IH-JAR) with the material value of the stainless and the aluminum for efficient design. The magnetic field intensity inside the axisymmetric shaped cooker was analyzed using three-dimensional axisymmetric finite element method(FEM) and the effectual heat source was obtained by ohmic losses from eddy currents induced in the jar. The heat was calculated using the heat source and heating equation. Also, it was represented the temperature characteristics of the IH-JAR according to time and relative permeability in stainless parts and in aluminum parts.

• Advances in materials Research
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• 제4권2호
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• pp.63-76
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• 2015

The energy crisis involving depletion of fossil fuel resource is not the sole driving force for developing renewable energy technologies. Another driving force is the ever increasing concerns on the air quality of our planet, associated with the continuous and dramatic increase of the concentration of greenhouse gas (mainly carbon dioxide) emissions. The internal combustion engine is a major source of distributed $CO_2$ emissions caused by combustion of gasoline derived largely from fossil fuel. Another major source of $CO_2$ is the combustion of fossil fuels to produce electricity. New technologies for generating electricity from sources that do not emit $CO_2$, such as water, solar, wind, and nuclear, together with the advent of plug-in hybrid electric vehicles (PHEV) and even all-electric vehicles (EVs), offer the potential of alleviating our present problem. Therefore, the relevant technologies in $LiFePO_4$ as cathode material for Li-ion batteries suitable to the friendly environment are reviewed aim to provide the vital information about the growing field for energies to minimize the potential environmental risks.

• Journal of Welding and Joining
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• 제34권4호
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• pp.1-8
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• 2016

Metal AM(Additive Manufacturing) has been steadily developed and that is classified into two method. PBF(Powder Bed Fusion) deposited in the bed by the laser or electron beam as a heat source of the powder material and DED(Directed Energy Deposition) deposited by varied heat source of powder and solid filler material. In the developed countries has been applying high productivity process of solid filler metal based DED method to the aerospace and defense sectors. The price of the powder material is quite expensive compared to the solid filler metal. A study on DED method that is based on a solid filler metal is increasing significantly although was low accuracy and degree of freedom.

• 한국결정성장학회지
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• 제29권3호
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• pp.83-90
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• 2019

본 논문에서는 전력 반도체 소자용 Mg-doped AlN 에피층을 혼합 소스 수소화물 기상 에피택시 방법에 의해 성장하였다. p형 재료로는 Mg을 사용하였다. 소자응용을 위한 기초 기판으로서 역할을 하기 위하여 GaN 에피층이 성장된 기판과 GaN 에피층이 성장되어 패턴이 형성된 사파이어 기판 위에 Mg-doped AlN 에피층을 선택 성장하였다. Mg-doped AlN 에피층의 표면과 결정 구조는 FE-SEM 및 HR-XRD에 의해 조사하였다. XPS 스펙트럼과 라만 스펙트럼 결과로부터 혼합소스 HVPE 방법에 의해 성장된 Mg-doped AlN 에피층은 전력소자 등에 응용이 가능할 것으로 판단된다.

• Journal of Electrochemical Science and Technology
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• 제13권3호
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• pp.407-415
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• 2022

Surface coating of cathodes is an essential process for all-solid-state batteries (ASSBs) based on sulfide electrolytes as it efficiently suppresses interfacial reactions between oxide cathodes and sulfide electrolytes. Based on computational calculations, Li₃PO₄ has been suggested as a promising coating material because of its higher stability with sulfides and its optimal ionic conductivity. However, it has hardly been applied to the coating of ASSBs due to the absence of a suitable coating process, including the selection of source material that is compatible with ASSBs. In this study, polyphosphoric acid (PPA) and (NH₄)₂HPO₄ were used as source materials for preparing a Li₃PO₄ coating for ASSBs, and the properties of the coating layer and coated cathodes were compared. The Li₃PO₄ layer fabricated using the (NH₄)₂HPO₄ source was rough and inhomogeneous, which is not suitable for the protection of the cathodes. Moreover, the water-based coating solution with the (NH₄)₂HPO₄ source can deteriorate the electrochemical performance of high-Ni cathodes that are vulnerable to water. In contrast, when an alcohol-based solvent was used, the PPA source enabled the formation of a thin and homogeneous coating layer on the cathode surface. As a consequence, the ASSBs containing the Li₃PO₄-coated cathode prepared by the PPA source exhibited significantly enhanced discharge and rate capabilities compared to ASSBs containing a pristine cathode or Li₃PO₄-coated cathode prepared by the (NH₄)₂HPO₄ source.

• 분석과학
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• 제20권6호
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• pp.502-507
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• 2007

X 선 회절법은 물질 내부에 원자의 배열 상태를 연구하는데 널리 사용되는 실험 방법으로써 넓은 응용 범위를 가지고 있다. 특히 분말 X 선 회절법은 비파괴적으로 다양한 형태의 시료에 대한 측정이 가능하기 때문에 결정의 배향성, 결정의 크기, 결정 내부의 응력 측정 등에 널리 이용되고 있다. 분말 X 선 회절 방법을 이용하여 혼합물의 성분을 정량적으로 측정하기 위해서는 시료를 구성하고 있는 source 스펙트럼을 도출하고 혼합된 시료의 XRD 스펙트럼에 회귀식을 적합시켜 혼합물 구성비를 얻는 방법이 제안된 바 있다. 그러나 구성성분의 특성상 스펙트럼의 피이크가 폭이 좁고 민감한 경우에는 노이즈의 영향을 받아 도출된 source 스펙트럼이 원래의 순수성분의 형태와 달리 나타날 수 있다. 특히 순수성분 시료를 구할 수 없거나 측정이 불가능한 경우 혼합물 구성비 측정에 어려움이 있다. 본 연구에서는 노이즈 간섭에 의한 source 스펙트럼 도출의 문제를 해결하는 방안으로 비음독립성분분석을 이용하여 혼합된 미지시료로부터 순수한 성분에 해당하는 스펙트럼을 분리해내는 방법을 제안하고자 한다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.369-375
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• 2002

The results of source location in terms of AE signal occurred by the spot exciting as suggested in this research, it has been confirmed that AE technique is quite fruitful in figuring out the location of the occurrence, form, size and direction of the defects. Thus, it is expected that the application of the experimental method suggested in this study would make it possible to identify, in the nondestructive way, the location of the defect in the material.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1002-1006
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• 2000

It is diffuse sound field that measuring condition of absorption ratio and sound transmission loss for material consist of building are measured in reverberartion room and on-site. In this study, for upkeeping diffuse sound field in reverberation room, it is measured and etimated that sound field is effected according to sound source lacation and characteristics of emission directivity for sound source.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.133-136
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• 2002

It is very important to get a stable and large-capacity organic effusion source for achievement of OLED mass-production equipment. We present an organic effusion source with film uniformity less than ${\pm}$ 5%, the material charge volume, 300cc for $400{\times}400\;mm^2$ substrate. The fine metal shadow mask alignment technology, one of the color forming technique, also have to support more accurate and fast operating in mass-production. In this paper, we will describe the OLED mass-production equipment with the large volume effusion source and the precision shadow mask alignment technique.

• 대한전자공학회논문지TC
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• 제47권5호
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• pp.60-68
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• 2010

통신서비스에 장애를 유발하는 전력선에 의한 전자유도 현상에 대한 방호를 위하여는 유도전압을 평가하여야 하고 상응한 대책을 수행하여야 한다. 유도전압을 평가하는 방식은 ITU 규격과 일본 유도자료로부터 국내에 도입되어 법률 고시화되어 있는데 이것으로 수용되지 못하는 유도 커플링상의 제원 요소들이 있다. 본 논문에서는 계산 수행 적용이 곤란한 범위를 포괄할 수 있도록 좀더 일반화된 고전적 유도 및 전자파 원론 해석 근간의 전자계 형성에 의한 소스와 관측점의 유도전압 산출 방식에 대한 기술을 분석하여 제시하였다.