• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2347-2349
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• 2004

The iron loss in electric machines takes large part of machine losses and the reduction of iron loss brings the increase of the efficiency. In the rotating machines, however it is very difficult to calculate result because the measuring processes are very complex and laborious. As is well known, the relation between the flux density B and the magnetic field intensity H relation is not linear. For the iron loss, B and H must be measured and usually B becomes the reference wave(sine wave) and the following H is measured using H-coil. To make the B as sine wave, B is controlled by some devices. The error is controlled to become zero by the proposed algorithm which uses the bisection algorithm. The experiments are compared with the simulation results, and they show acceptable agreements.

• 전자공학회논문지D
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• 제35D권4호
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• pp.24-31
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• 1998

The far-zone magnetic field patterns of a E-plane horn antenna with various edge structures are analyzed using UTD. The ray tracing method is used to lacate the shadow boundaries, and then GO and UTD are utilized to evaluate the incident, reflected, diffracted, surface diffaracted, and the second order diffracted, diffracted-reflected, and diffracted-reflected-diffracted waves existing in each region of interest. By doing this, we analyzed the effects of flanges or caps connected on the edge of a horn antenna on the side lobe and back lobe levels. Also, the validity of this paper is proved by comparing the analytical results with those of measurement and method of moment presented in the reference.

• 천문학논총
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• 제20권1호
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• pp.117-124
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• 2005

We plan to install the polarimetric optics in the AGU(acqusition and guiding unit) of the 1.8 m telescope at the BOAO(Bohyunsan Optical Astronomy Observatory). With this, the spectropolarimetric observations with the resolution of 45,000 and 60,000 in 4,000 to $8,000{\AA}$ ange could be done by the BOES(BOao Echelle Spectrograph). If we use the precision radial velocity measurement capability of the BOES, the accuracy of the magnetic field intensity measurements with this new BOES stokesmeter will be much increased. We present here the design concept of the BOES stokesmeter. Some details on the optics, mechanical parts, fiber parts and the lab test procedures of this stokesmeter are explained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.683-687
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• 1997

The purpose of this work is to develop a highly reliable solar cell based on the diamond-like carbon(DLC)/silicon heterojunction. Thin films of DLC have been deposited by employing both filtered cathodic vacuum arc(FCVA) and magnetron plasma-enhanced chemical vapor deposition(m-PECVD) systems. Structural, electrical, and optical properties of DLC films deposited are systematically analyzed as a function of deposition conditions, such as magnetic field, substrate bias voltage, gas pressure, and nitrogen content. The I-V measurement has been used to elucidate the mechanism responsible for the conduction process in the DLC/Si junction. Photoresponse characteristics of the junction are measured and its reliability against temperature and light stresses is also analyzed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.627-628
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• 2008

본 논문에서는 수직 자계를 이용한 배관 내 자성체를 측정하는 시스템을 개발하였다. 자성체 면적 변화에 따른 측정 신호의 정밀도를 높이기 위해 배관 내 자기장의 크기 및 균일도를 고려한 설계 및 해석을 하였다. 인가 자기장의 크기는 반도체 소자의 노이즈 레벨($0.4{\sim}0.6$[G])보다 크고, 대상물체의 1% 면적 변화에 따른 ${\Delta}B$의 민감도를 고려하였으며, 코어의 형상 및 길이를 변화에 따른 배관 내 자기장의 크기와 균일도를 유한요소법을 이용하여 해석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.58-60
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• 1999

In the industrial field the necessity of the linear motion is increasing. We selected a moving magnet coreless type LDM, which have the advantages, such as long stoke, brushless, no cogging force. Actually, the design is accomplished using FEM analysis for the basic configuration of a magnetic circuit, and characteristic equations for coil design. In the course of design, we have estimated airgap flux density and thrust. We fabricated coreless type LDM and experimented static test. We compared measurement values with FEM analysis values.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2002년도 하계 학술대회 논문집
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• pp.424-431
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• 2002

마이크로파 주파수는 일반적으로 1㎓-30㎓ 정도로서 주파수가 매우 높기 때문에 도체뿐만 아니라 절연체와 공기 중에서도 전류가 흐르는 성질을 갖는다. 자유공간에서의 마이크로파를 전자파라고도 하며 그 속도는 빛의 속도와 동일하며 자유공간에서 1cm-30cm 파장 범위를 가지므로 센티파라고도 한다. 전자방사(electromagnetic radiation)은 공간을 통하여 시간에 따라 변하는 전자계(electric and magnetic field)에 의한 에너지의 전파(propagation)이며 파동이론과 (wave theory)와 미립자이론(corpuscular theory)에 의해 해석될 수 있다. 전자파 이론(electromagnetic wave theory)의 기초는 1864년 Maxwell이 전자기 현상에 관하여 지배방정식을 수립함으로써 정립되었으며 1888년 Hertz에 의해 마이크로파의 존재가 실험적으로 증명되었다. 이후 마이크로파 기술은 2 차 세계대전을 거치면서 크게 발전하였으며 초기의 레이더 및 통신 등과 같은 군용 기술에서 마이크로파 건조 및 센싱과 같은 산업응용 기술로 발전하게 되었다. 특히 마이크로파 센서기술 및 가열기술은 농업 및 식품분야에 응용되어 마이크로파 응용제품을 선보이게 되었다. (중략)

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 사면안정 학술발표회
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• pp.60-76
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• 2000

Early detection in real-time response of slope movements ensures tremendous saving of lives and repair costs from catastrophic disaster Therefore, it is essential to constantly monitor the performance and integrity of slope-stabilizing structures such as Rock bolt, Nail and Pile during or after installation. We developed a novel monitoring system using Fiber Bragg Grating (FBG)sensor. It's advantages are highly sensitivity, small dimension and electro-magnetic immunity. capability of multiplexing, system integrity, remote sensing - these serve real-time health monitoring of the structures. Real-time strain measurement by the signal processing program is shown graphically and it gives a warning sound when the monitored strain state exceeds a given threshold level so that any sign of abnormal disturbance on the spot can be easily perceived.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.49-51
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• 2004

The iron loss in electric machines takes large part of machine losses and the reduction of iron loss brings the increase of the efficiency. In the rotating machines, however it is very difficult to calculate the iron loss and to get the exact experiment result because the measuring precesses are very complex and laborious. As is well known, the relation between the flux density B and the magnetic field intensity H relation is not linear. For the iron loss, B and H must be measured and usually B becomes the reference wave(sine wave) and the following H is measured using H-coil. To make the B as sine wave, B is controlled by some devices. The error is controlled to become zero by the proposed algorithm which uses the bisection algorithm. The experiments are compared with the simulation results, and they show acceptable agreements.

• 반도체디스플레이기술학회지
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• 제15권4호
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• pp.33-35
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• 2016

In this study, a new plasma source was used in the ALD process. Line type plasma sources were analyzed by electric and magnetic field simulation. And the results were compared with plasma density and electron temperature measurement results. As a result, the results of the computer simulation and the diagnosis results of plasma density and electron temperature showed similar tendency. At this time, the plasma uniformity is 95.6 %. $Al_2O_3$ thin film was coated on 6 inch Si-wafer, using this plasma source. The uniformity of the thin film was more than 98% and the thin film growth rate was 0.13 nm/cycle.