• 한국실천공학교육학회논문지
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• 제2권2호
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• pp.55-60
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• 2010

평상시 전자기 현상들을 접하고 있는 우리들은 이러한 현상들의 단편적인 면은 느낄 수 있으나 시각적으로 파악하기 어려운 현상이며 더욱이 물리 및 정량적으로 이해하기란 쉬운 일이 아니다. 이들 정전기장, 정자기장 또한 전자장이 결합되어있는 교류자장은 실험식과 이론적으로 James Clerk Maxwell에 의해 1873년도에 완성되었다. 따라서 전자장은 Maxwell방정식에 근거를 둔 수식의 전개로 전기 자기 현상을 다룬다. 이러한 수식전개가 바탕이 되는 학문이기에 처음으로 전자기를 배우는 중 고등학교 학생, 대학 기본과목인 대학 물리를 배우는 대학생, 이와 관련된 전공 학생에게 조차 이해하기에 어려움이 따른다. 따라서 이러한 난점들을 해결하고자 전자기 제반현상들을 시각적으로 파악하고 더 나아가 수식적으로 해를 구하기 어려운 문제들을 수치해석방법을 이용해 해의 거동을 추정할 수 있도록 하는 학부 수준의 가상 교육용 전자장 프로그램을 개발하고자 하였다.

• 한국산학기술학회논문지
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• 제5권5호
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• pp.385-388
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• 2004

본 논문에서는 격자구조의 유전체에 수직으로 입사된 전자기파의 산란, 투과 특성을 얇은 위상 막 근사화 이론을 이용하여 분석하였다. 위상 막 근사화 이론은 격자구조가 입사되는 전자기파의 위상 변화만을 주는 것으로 간주하는 것으로 이를 이용하여 격자구조를 통과한 직후인 근거리 필드 분포를 TE 모드에서 계산하였다. 기존의 제시된 이론에 비해 비교적 간단하고 빠르게 산란 필드를 분석할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2462-2464
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• 1999

All electric and electronic appliances require their own electromagnetic compatibility. So an industrially advanced nations have made many standards for regulation for their profits thus the researches on the electro-magnetic shielding effect(SE) are being increased. But the SE can not proved its effect by a theory alone because of complex-material problems. This study Present the correlation of the SE and immunity of radiated radio frequency of the electromagnetic field. We have analyzed the theory of shielding effect to the shield texture. It has been proved that experimental results showed this effects have intensive relations to the electromagnetic field immunity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.46-48
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• 1994

In this paper, for optimum design and good efficiency, the characteristics of a induction motor is analyzed by using electromagnetic field theory, Maxwell'equation with consideration of slot-teeth shape, materials, etc.

• Interaction and multiscale mechanics
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• 제1권4호
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• pp.467-476
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• 2008

In this work, a nano-size rocksalt crystal (magnesium oxide) is considered as a continuous collection of unit cells, while each unit cell consists of discrete atoms; and modeled by a multiscale concurrent atomic/continuum field theory. The response of the crystal to an electromagnetic (EM) wave is studied. Finite element analysis is performed by solving the governing equations of the multiscale theory. Due to the applied EM field, the inhomogeneous motions of discrete atoms in the polarizable crystal give rise to the change of microstructure and the polarization wave. The relation between the natural frequency of this system and the driving frequency of the applied EM field is found and discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.991-993
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• 1999

The method of measurement for contactless eddy-current conductivity using magnetic dipole field theory was suggested by M.C Chen[1], which calculate the eddy-current caused by exciting coil with Faraday's induction law. In this work, we have developed the apparatus for contactless measurement of conductivity or resistivity with the dipole field theory. The resistivity can be measured from several to a dozen $m{\Omega}{\cdot}cm$ range within maximum 30% error. At the high resistivity range above $100{\Omega}{\cdot}cm$, the standard deviation of measurement was very large as the induced voltage of sensing coil is small so it was difficult to measure the value precisely.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.715-716
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• 2006

Nowadays, research of EMI/EMC is very important in electromagnetic wave surroundings generated from many electric and electronic devices. Especially, analysis of electromagnetic radiation characteristic and field have to be performed first of all. At the present most of EMI/EMC problems are solved by the method of practice and inspiration. Hence in this paper, will provide the first step for solving EMI/EMC problems in design process. Model of analysis is structure composed of PCB and Frame. By the first step, theory of dipole antenna is adapted to analyze electromagnetic radiation characteristic and field. Because it is fundamental of analysis of electromagnetic radiation. And it will be expanded for structure of PCB and Frame. Finally, it provide the basic method of analysis of electromagnetic radiation characteristic and field by making similar dipole antenna to PCB and Frame structure.

• 전기의세계
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• 제30권4호
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• pp.219-226
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• 1981

The magnetic field distribution in saturable iron part of electromagnetic energy conversion divices is defined by the nonlinear quasi-Poisson enquation that is described the electromagnetic field characteristics and satisfied the natural boundary condition. The solution of this equation is obtained by minimizing an energy functional by means of trial function that defined in triangular subregion of two-dimensional field region. As a result, the accuracy of the machine design is increased by use of its solution. In this respect, this study is developed the basic theory to analyze the magnetic flux distribution in saturable iron part and air gap of induction motor that its secondary part is short circuit by the variational principle, the minimized theory of energy functional, the application of F.E.M., and treatment of computer. As theoritical data compared with the practics, the validity of the theory in this study is supported by experimental findings.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.549-552
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• 2003

The electrical current generated by heart creates not only electric potential but also a magnetic field. We have observed electrophysiological phenomena of the heart by measuring tangential components of magnetocardiogram(MCG) using 61 channel superconducting quantum interference device(SQUD) system. In this paper, we developed a new analysis method, which is based on the theory of electromagnetic field. We show some differences of the current direction between the normal MCG and the abnormal(ischemic heart disease) MCG.

• 한국안전학회지
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• 제21권2호
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• pp.22-28
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• 2006

This paper presents assessment of possibility on the human risk for the electromagnetic field of unbalanced two coupled three-phase transmission line using fuzzy theory. Three phase load flow program was developed which employed a Newton-Raphson method as a tool to analyze system unbalanced. This research presents a method of handling two coupled three phase transmission system unbalance analysis and unbalanced power demand as a function of voltages. As the results of case study, in case of 345[kV] T/L, the electric field intensity was 10.9540[kV/m], magnetic field intensity was 0.2567[G] in severest case. The results showed that the membership of a proposition fuzzy '10.9540 [kV/m] is hazardous' is 0.6349. As the analytic results using the fuzzy qualifier term, the membership in case of very false is 0.1379 and fairly false is 0.6124, respectively. In assessment of fuzzy measure possibility for the electromagnetic field, this paper used probability of fuzzy arid measure of fuzziness technique.