• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.943-945
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• 2000

In this paper described that study on the distribution and characteristics of axial magnetic field by mathematical analysis and experiment for axial magnetic field type vacuum interrupter that important part on vacuum circuit breaker. And, it was shown that inspected results of arc shape at breaking the current by typical axial magnetic field type model and new axial magnetic field type model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.672-674
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• 2001

Axial magnetic field(AMF) type electrode can increase the interrupting capability of vacuum interrupters. But, this interrupting capability vary with design parameters such as shape of electrode, slits of contact, material of contact and so on. In this paper, shown arc characteristics of unipolar axial magnetic field type electrode for vacuum interrupter by design parameters such as shape of contact slits and diameter of contact. And, confirmed vacuum arc configuration by individual design parameter using high speed camera.

• Applied Science and Convergence Technology
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• 제25권6호
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• pp.154-157
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• 2016

The energy dispersion and magnetization of a modified magnetic dot are investigated numerically. The effects of additional electrostatic potential, magnetic field non-uniformity, and Zeeman spin splitting are studied. The modified magnetic quantum dot is a magnetically formed quantum structure that has different magnetic fields inside and outside of the dot. The additional electrostatic potential prohibits the ground-state angular momentum transition in the energy dispersion as a function of the magnetic field inside the dot, and provides oscillation of the magnetization as a function of the chemical potential energy. The magnetic field non-uniformity broadens the shape of the magnetization. The Zeeman spin splitting produces additional peaks on the magnetization.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.22-24
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• 1997

The 4-pole LHSM was composed of the figure-of-eight shaped 3-phase armature windings. DC field windings, and the segmented secondary with the transverse bar track. The motor was designed on the base of the performance characteristic equations and the equivalent circuit model, with the coefficients of the magnetic shape. These coefficients were computed from the analytical expressions and examined from FEM analysis. The magnetic equivalent circuit of 3-D model of LHSM was obtained. and this concept provided the equivalent models for 2-D FEM analysis. Therefore, the airgap field, the lift and thrust force were calculated and compared with the results of magnetic equivalent circuit method.

• 전기전자학회논문지
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• 제22권1호
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• pp.61-67
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• 2018

We investigated theoretically the magnetic field dependence of the quantum optical transition of qusi 2-Dimensional Landau splitting system, in CdS and ZnO. In this study, we investigate electron confinement by square well confinement potential in magnetic field system using quantum transport theory(QTR). In this study, theoretical formulas for numerical analysis are derived using Liouville equation method and Equilibrium Average Projection Scheme (EAPS). In this study, the absorption power, P (B), and the Quantum Transition Line Widths (QTLWS) of the magnetic field in CdS and ZnO can be deduced from the numerical analysis of the theoretical equations, and the optical quantum transition line shape (QTLS) is found to increase. We also found that QTLW, ${\gamma}(B)_{total}$ of CdS < ${\gamma}(B)_{total}$ of ZnO in the magnetic field region B<25 Tesla.

• 대한금속재료학회지
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• 제49권6호
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• pp.505-513
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• 2011

A magnetic device which enables the application of a strong and uniform magnetic field to thin film during sputtering was designed for controlling the magnetic anisotropy using a three dimensional finite element method, and the effects of the external magnetic field on the magnetic properties of sputtered thin films were investigated. Both the intensity and the uniformity of the magnetic flux density in the sputter zone (50 mm ${\times}$50 mm) was dependent on not only the shape and size of the magnet device but also the magnitude of stray fields from the magnet. For the magnet device in which the distance between two magnets or two pure iron bars was 80-90 mm, the magnetic flux density along the direction normal to the external magnetic field direction was minimum. The two row magnets increased the magnetic flux density and uniformity along the external magnetic field direction. An Fe thin film sputtered using the optimized magnet device showed a higher remanence ratio than that fabricated under no external magnetic field.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.315-317
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• 2002

The value of I$_{c}$(critical current) in HTS (High Temperature Superconducting) tape has a great influence on B(equation omitted) (magnetic field amplitude applied perpendicular to the tape surface). Therefore, I$_{c}$ of HTS magnet is determined by not only operating temperature but also the B(equation omitted). In shape design of field coil for the HTS motor, a method to reduce the B(equation omitted) and to determine operating current should be considered in order to optimal design. On the basis of the magnetic field analysis, this paper deals with various field coil shape to obtain operating current of HTS motor by using analytical method. And also this paper discusses the operating current of 100hp class HTS motor by using I$_{c}$-B(equation omitted) curve.curve.

• 한국초등과학교육학회지:초등과학교육
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• 제26권4호
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• pp.440-448
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• 2007

The purpose of this study is to examine elementary students' conceptions of magnetic fields around various magnets by drawing tasks. A total of 105 elementary students from the 3rd and 6th grade levels were asked to draw how iron filings would arrange around magnets. We classified their drawings of magnetic field lines with some criteria to identify conceptions of magnetic forces and checked them through interviewing about their representative drawing. Through analyzing drawings, we discovered that 40% of elementary students drew the correct arrangement of iron filings around a bar magnet. In the case of two bar magnets in opposite directions, 33% of them drew correct patterns of iron dust and around two magnets in the same direction only 20% did well. Only 2.9% and 7.6% of students presented the correct drawings of magnetic fields near a disc and a horseshoe magnet. While 3rd grade students were supposed to be poor in drawings of magnetic fields around a loose and a dense coil which was not learned about, only 31% and 23% of 6th grade students who have just studied electromagnetism properly drew patterns of iron dust. This shows that only one quarter of students understood the magnetic filed lines even after instruction of electromagnetism. Many of 6th grade students learned a solenoid becomes just as a permanent magnet, but very few of them correctly drew a magnetic field line could distinguish between the iron dust around a loose and dense coil. After interviewing students, it is found that students consider magnetic forces to be existed only in parts of magnet because many of them drew magnetic field line of a specific areas around magnets. Students had misconceptions that magnetic forces exist only on the poles not in the middle around a horseshoe magnet. Also the disc-shape magnet made students to reveal various types of misconceptions: N- and S-poles are mixed in a whole magnet and right part of a disc-shape magnet is N-pole, left part is S-pole. Students who had not studied magnetic fields of around a magnet and electromagnets could not draw the correct patterns of iron dust suggest that it is indispensable for students to teach how patterns of iron filings would represent a visual image of magnetic fields in order to understand magnetic fields.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3611-3616
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• 2013

MR 유체의 물리특성은 자기장에 의해 영향을 받는다. 본 연구에서는 MR 유체의 자기장에 의한 유동변화를 실험적으로 조사하고자, MR 유체의 밀도와 점도를 변경하면서 자기장에 의한 유동 가시화와 전단응력 변화를 측정하였다. 이를 위해 밀도 3종, 점도 3종에 대한 MR 유체를 제조하였고 MR 유체 가시화 실험장치를 제작하였다. 자기장이 인가되면, MR 유체 파우더의 유동흐름은 띠를 형성하면서 자기장이 인가되지 않은 경우와는 다른 유동흐름을 보여주었다. 또한 전단응력은 인가전류와 밀도가 높을수록 더 크게 증가하였으며, 인가전류 2.0A에서 MR 유체의 밀도가 $1300kg/m^3$에서 $1700kg/m^3$ 로 변하면 전단응력은 33% 정도 증가하였다.

• 한국결정성장학회지
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• 제18권4호
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• pp.140-145
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• 2008

Cz법을 이용하여 다양한 성장 조건하에서 실리콘 단결정이 성장되었따. 고액 계면 형상의 차이는 다양한 자기장 분포를 통하여 구현되었으며 결정의 고액 계면에 있어 ZGP(zero-Gauss plane) 형태와 자기장 세기(MI)의 효과가 실험적으로 연구되었따. ZGP의 형태는 커습 자기장에 있어 상부 및 하부 코일에 인가되는 자기장의 비율(MR)로 인하여 평평하거나 포물선의 형태를 갖게 된다. MR이 증가함에 따라 고액 계면은 더욱 음각(more concave)의 형태가 되고 이는 MR 증가에 따른 고액 계면으로의 뜨거운 융액이 쉽게 유입될 수 있음을 의미한다. 고액 계면의 효과적인 형상은 자기장 분포에 의존됨을 발견하였으며 실험결과는 다른 연구와 비교하였다.