• 한국자기학회:학술대회 개요집
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• 한국자기학회 2012년도 임시총회 및 하계학술연구발표회
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• pp.32-32
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• 2012

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.115.2-115.2
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• 2008

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.280.1-280.1
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• 2008

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2016년도 임시총회 및 하계학술연구발표회
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• pp.159-159
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• 2016

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2016년도 임시총회 및 하계학술연구발표회
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• pp.95-96
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• 2016

• Applied Microscopy
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• 제47권1호
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• pp.29-35
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• 2017

Transverse magnetic field annealing (TFA) was carried out on $Fe_{73.5}Cu_1Nb_3Si_{15.5}B_7$ nano-crystalline magnetic core with the aim at decreasing coercivity ($H_c$) while keeping high inductance ($L_s$). The magnetic field generated by direct current (DC) was applied on the magnetic core during different selected annealing stages and it was proved that the nanocrystalline magnetic core achieved lowest $H_c$ when applying transverse field during the whole annealing process (TFA1). Although the microstructure and crystallization degree of the nanocrystalline magnetic core exhibited no obvious difference after TFA1 compared to no field annealing, the TFA1 sample showed a more uniform nanostructure with a smaller mean square deviation of grain size distribution. $H_c$ of the nanocrystalline magnetic core annealed under TFA1 decreased along with the increasing magnetic field. As a result, the certain size nanocrystalline magnetic core with low $H_c$ of 0.6 A/m, low core loss (W at 20 kHz) of 1.6 W/kg under flux density of 0.2 T and high $L_s$ of $13.8{\mu}H$ were obtained after TFA1 with the DC intensity of 140 A. The combination of high $L_s$ with excellent magnetic properties promised this nanocrystalline alloy an outstanding economical application in high frequency transformers.

• 한국자기학회지
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• 제26권5호
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• pp.154-158
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• 2016

원자력발전소의 원자로에는 노심 반응 속도를 제어하기 위하여 제어봉구동장치가 사용된다. 한국원자력연구원의 SMART 원자로는 원자로 가동 중 제어봉집합체의 위치를 확인하기 위하여 제어봉구동장치에 영구자석과 리드스위치로 구성되는 위치지시기가 설치된다. 원자로 가동 온도는 최대 $350^{\circ}C$로 고려되어 설계되며, 영구자석은 원자로 내에 설치된다. 반면에 리드스위치와 전기회로는 원자로 외부에 설치된다. Test coil은 리드스위치의 품질 검증을 위한 장비로서, 코일과 철심으로 구성되어 있다. 본 연구는 리드스위치에 미치는 Test coil과 영구자석의 자기 특성을 비교하고자 수행되었으며, 유한요소 전자기 시뮬레이션을 활용하였다.

• 천문학회보
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• 제36권2호
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• pp.102.1-102.1
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• 2011

In this study we use three-dimensional magnetohydrodynamic simulations to investigate how the dynamic state of emerging magnetic field is related to the twist of field lines. Emerging magnetic field forms a magnetic structure on the Sun where various kinds of activity such as solar flares, jets, and coronal mass ejections are observed. To understand the physical mechanism for producing such activity, we have to know the dynamic nature of this structure. Since flares are the manifestation of rapidly dissipating electric current in the corona, we also investigate the distribution of current density inside the structure and examine how it depends on the field-line twist. To demonstrate the dynamic structure of emerging magnetic field, we focus on the factors characterizing the geometric property and stratification of emerging magnetic field, such as the curvature of field line and the scale height of field strength. These two factors show that emerging field forms a two-part structure in which the central part is close to a force-free state while the outer marginal part is in a fairly dynamic state where magnetic pressure force is dominant. We discuss how the field-line twist affects the two-part structure and also explain a possible relation between electric current structure and sigmoid observed in a preflare phase.

• Journal of electromagnetic engineering and science
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• 제5권3호
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• pp.117-121
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• 2005

We compared electromagnetic(EM) wave absorption properties between Alnico magnet (A) and (B) with different magnetic properties. Also, we investigated the effect of carbon, thickness of absorbers, and Alnico contents on EM wave absorption, and clarified the relation between Alnico content and central frequency.

• Bulletin of the Korean Chemical Society
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• 제34권7호
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• pp.2203-2206
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• 2013