• Title/Summary/Keyword: Maxwell Equations

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An Analysis of Electromagnetic Field Scattering for the Dielectric Cylinders (유전체주의 전자장 산란 해석)

  • 박동희;김정기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.2
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    • pp.181-186
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    • 1992
  • The scattering property of TMz illuminated perfectly conducting and dielectric cylinders of arbitrary cross section are analyzed by the boundary element techniques. The boundary element equations are formulated via Maxwell’s equations, weighted residual or Green’s theorem, and the boundary conditions. The unknown surface fields on the boundaries are then calculated by the boundary element integral equations. Once the surface fields are found, the scattered fields in from a perfectly conducting circular and elliptic cylinders, a dielectric circular and elliptic cylinders are numerically analyzed. A general computer program has been developed using the quadratic elements(higher order boundary elements) and the Gaussian quadrature.

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Numerical Modeling for Behavior Prediction of the Magnetic Fluid Based on Finite Element Method (유한요소법을 이용한 자성유체의 거동예측을 위한 수치적 모델링)

  • Seo, Jae-Hyeong;Lee, Moo-Yeon;Seo, Lee-Soo
    • Journal of the Korean Magnetics Society
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    • v.23 no.1
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    • pp.31-35
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    • 2013
  • The objective of this study is numerically analyzed the behavior characteristics of the magnetic fluid in a closed rectangular container using finite element method (FEM). The governing equations are solved with magnetization and Maxwell equations for consideration of rotating effect of the magnetite particle. Then the discretized equations are solved with boundary conditions of the velocity and temperature. The developed model is validated with the results of Davis (1983) and Fusegi et al. (1991) has a good agreement within 5.5 % and 2.7 %, respectively.

the Combination of Wavelet with Boundary Element Method for the Efficient Solution of Maxwell's Equations (Maxwell 방정식의 효율적인 풀이를 위한 경계요소법과 웨이브렛의 결합)

  • Kim, Hyun-Jun;Lee, Seung-Gol;O, Beom-Hoan;Lee, El-Hang
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.39 no.6
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    • pp.24-35
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    • 2002
  • The wavelet transform is combined with the boundary element method (BEM), to solve efficiently the Maxwell's equation and the proposed method is applied to the electromagnetic problem for the analysis of topological effects of phase-shifting masks. The accuracy of the module developed was verified by comparison with both analytic solutions and published results. In addition, it was found that the boundary element method in combination with the wavelet matrix transform would be more efficient than the conventional methods based on the BEM in views of the calculation speed and the usage of computer memory.

Analysis of a Dipole Antenna Using Maxwell-SCHRÖDINGER Equation (맥스웰-슈뢰딩거 방정식을 이용한 다이폴 안테나 해석)

  • Kim, Jinyoung;Jung, Jaeyoung;Jung, Youngbae;Jung, Changwon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3107-3113
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    • 2014
  • We present a quantitative analysis of a dipole antenna and its characteristics from the viewpoint of quantum mechanics. The method makes use of a Maxwell equation used in an existing antenna propagation formula. This includes radiation resistance, input reactance, and antenna efficiency as functions of frequency and antenna length. Particular attention is paid to the Schr$\ddot{o}$odinger equation. We accomplish E-field and H-field analyses of a dipole antenna by combining the Maxwell and Schr$\ddot{o}$odinger wave equations. When comparing the existing Maxwell wave equation with the Schr$\ddot{o}$odinger wave equation, quantum-electric movement is more accurate than using the Maxwell wave equation alone.

Polarization Properties of Signals in $Bi_{12}SiO_{20}$ Electrooptic Devices (비스무스실리콘 산화물 단결정을 이용한 전기광학 장치에서의 편광 특성)

  • 김상국
    • Korean Journal of Optics and Photonics
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    • v.1 no.1
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    • pp.16-21
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    • 1990
  • The accurate polarization state of the light inside BSO crystal was calculated with consideration of optical activity. By solving Maxwell's equations, the general form of the polarization matrix for any direction of the electric field was obtained. Examples of output polarization states in BSO crystals were also calculated, and their properties were discussed.

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A Finite Element Based PML Method for Time-domain Electromagnetic Wave Propagation Analysis (시간영역 전자기파 전파해석을 위한 유한요소기반 PML 기법)

  • Yi, Sang-Ri;Kim, Boyoung;Kang, Jun Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.2
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    • pp.123-130
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    • 2015
  • This paper presents a new formulation for transient simulations of microwave propagation in heterogeneous unbounded domains. In particular, perfectly-matched-layers(PMLs) are introduced to allow for wave absorption at artificial boundaries used to truncate the infinite extent of the physical domains. The development of the electromagnetic PML targets the application to engineering mechanics problems such as structural health monitoring and inverse medium problems. To formulate the PML for plane electromagnetic waves, a complex coordinate transformation is introduced to Maxwell's equations in the frequency-domain. Then the PML-endowed partial differential equations(PDEs) for transient electromagnetic waves are recovered by the application of the inverse Fourier transform to the frequency-domain equations. A mixed finite element method is employed to solve the time-domain PDEs for electric and magnetic fields in the PML-truncated domain. Numerical results are presented for plane microwaves propagating through concrete structures, and the accuracy of solutions is investigated by a series of error analyses.

SPECTROSCOPIC ADMITTIVITY IMAGING OF BIOLOGICAL TISSUES: CHALLENGES AND FUTURE DIRECTIONS

  • Zhang, Tingting;Bera, Tushar Kanti;Woo, Eung Je;Seo, Jin Keun
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.18 no.2
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    • pp.77-105
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    • 2014
  • Medical imaging techniques have evolved to expand our ability to visualize new contrast information of electrical, optical, and mechanical properties of tissues in the human body using noninvasive measurement methods. In particular, electrical tissue property imaging techniques have received considerable attention for the last few decades since electrical properties of biological tissues and organs change with their physiological functions and pathological states. We can express the electrical tissue properties as the frequency-dependent admittivity, which can be measured in a macroscopic scale by assessing the relation between the time-harmonic electric field and current density. The main issue is to reconstruct spectroscopic admittivity images from 10 Hz to 1 MHz, for example, with reasonably high spatial and temporal resolutions. It requires a solution of a nonlinear inverse problem involving Maxwell's equations. To solve the inverse problem with practical significance, we need deep knowledge on its mathematical formulation of underlying physical phenomena, implementation of image reconstruction algorithms, and practical limitations associated with the measurement sensitivity, specificity, noise, and data acquisition time. This paper discusses a number of issues in electrical tissue property imaging modalities and their future directions.

FDTD Calculation for SAR Induced in a Head Model by the Electromagnetic Fields Irradiated from a Cellular Phone (휴대폰 전자파에 노출된 頭部에 흡수되는 SAR의 FDTD에 의한 해석)

  • 이윤경;임현준;우종우;윤현보
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.1
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    • pp.1-7
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    • 1998
  • The near field radiated from the monopole antenna of the cellular phone was calculated by using the modified finite difference time domain algorithm derived from the integral form of Maxwell's equations. Substituting the near field value into the differential form of Maxwell's equations, SAR's distribution in the human head was obtained. The human head was simulated by a model of 800,000 block cells with dielectric constant and conductivity. The cell size was taken to be 0.5 cm. the transmitted power of the cellular phone was assumed to be 0.6 watts at the frequency of 833 MHz. The distance between the head and the cellular phone was 2.0 cm, the maximum SAR induced in the human head was about 1.5 W/kg and was below the IEEE's upper safety limit of 1.6 W/kg.

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The Analysis of Flow Characteristics of Conductive Liquid Metal Using TLIM Electromagnetic Pump (TLIM 전자펌프를 이용한 전도성 용융금속의 유동특성 해석)

  • Kim, Chang-Eob;Jeon, Mun-Ho;Kwon, Jeong-Tae;Lim, Hyo-Jae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.12
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    • pp.130-141
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    • 2008
  • This paper presents the flow characteristics in the fluid circulation loop using the tubular type linear induction motor(TLIM) electromagnetic pump. A TLIM of thrust 40[N] is analyzed using the equivalent and genetic algorithm for the system The flow characteristics are analyzed by coupling the Maxwell equations with the Navier-Stokes equation with the thrust. The analysis algorithm is developed for analyzing the liquid metal flow in the system for laminar and turbulent flow. And the effect of thrust is analyzed for the flow characteristics.