• Title/Summary/Keyword: 전자기장 분석

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ULF electromagnetic variation associated with seismic wave (지진파에 의해 발생하는 ULF 전자기장 변동)

  • Lee Heuisoon;Lee Choon-Ki;Kwon Byung-Doo;Yang Jun-Mo;Oh Seokhoon;Song Yoonho;Lee Tae Jong;Uchida Toshihiro
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.05a
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    • pp.197-202
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    • 2005
  • The electromagnetic signals associated with the seismic activity in the south-east offshore of Kii peninsula, Japan, were clearly recorded at the MT sites in Jeju island, Korea. In this research, we have identified the co-seismic electromagnetic signals associated with the seismic activity and have analyzed the characteristics of significant electromagnetic variations. The analysis of phase velocity, power spectral density, MT impedance and polarization direction shows that the significant earthquake signals have the frequency band of about 0.05 to 0.5 Hz and that the sources of electromagnetic field are local effects of passing seismic waves. The simple approximation using electrokinetic effect successfully explains the co-seismic EM signals coincides with measured data but cannot explain the localities of electromagnetic variations.

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Field Strength Standards in 30~ 1000MHz Frequency Range (30~1000MHz 주파수 범위에서의 전자기장의 세기 표준)

  • 김정환;강찬구
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.12
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    • pp.1893-1901
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    • 1993
  • This paper presents the field strength standard established using a standard antenna method in the frequency range of 30~1000MHz at KRISS(Korea Research Institute of Standards and Science). Designs on antenna elements and a balun, and the characteristics of an antenna voltmeter are described. The uncertainties in generation the standard fields are analzed and estimated to be 5~14%.

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The Statistical Technique for Dosimetric Meta-Analysis at in-vivo and in-vitro Papers about Bioeffects of RF Electromagnetic Field (RF 전자기장 생체 영향 연구 문헌에서 노출량 메타분석을 위한 통계적 기법)

  • Choi, Sung-Ho;Kim, Nam
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.12
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    • pp.1311-1320
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    • 2003
  • This paper proposed the estimating method of electromagnetic dosimetric reliability at in-vivo and in-vitro experiments. For more accurate consequences of these researches, we have tried to find out any correlations among output power, power density and specific absorption rate(SAR) with the results of in-vivo, in-vitro tests and SAR reports of cellular phone and PDA. In the case of in-vivo tests, the power density has close statistical correlations with SAR value and in the event of in-vitro tests, the output power has considerable statistical correlations with SAR containing duty factor. We analysed the coefficient of determination to estimate the dosimeoic uncertainty. If we use this method before evaluating techniques of measurement and analysis at both in-vivo and in-vitro experiments, we will conduct more accurate reliability test.

시뮬레이션을 이용한 저온 대기압 플라즈마 소스의 전자기장 분석

  • Yun, Myeong-Su;Jo, Lee-Hyeon;Kim, Dong-Hae;Jo, Tae-Hun;Jeon, Bu-Il;Jo, Gwang-Seop;Gwon, Gi-Cheong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.515-515
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    • 2012
  • 일반적으로 저온 대기압 플라즈마는 표면개질이나 의료도구, 식수등 살균장치에 많이 이용되고 있으며 현재에는 혈액응고, 치아 치료등의 바이오분야에도 활발한 연구가 진행되어지고 있다. 그러나 저온 대기압 플라즈마는 가스 유량, 전극간격, 물질, 모양에 따라 인가되어지는 전자기장이 특성이 상이하다. 본 연구에서는 시뮬레이션을 이용하여 저온 대기압 플라즈마 젯(jet) 소스에서 전극의 간격에 따른 전자기장의 세기를 계산하였고, 전극의 거리별 저온 대기압 플라즈마 젯(jet) 소스에서 인가되는 전압과 비교를 해보았다. 그 결과 시뮬레이션 값과 실험결과가 유사한 경향을 보이는 것을 본 연구에서 확인할 수 있었다.

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Experimental study on flow characteristics for the high efficiency transporting of the dredged soil (준설토 이송고효율화를 위한 유동특성의 실험적 분석)

  • Kim, Yu-Seung;Lee, Myung-Han;Lee, Su-Yeon
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.1
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    • pp.71-81
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    • 2016
  • To evaluate the effects of magnetic force for transporting the dredged soil, magnetic energy inducing device was installed at the dredger. The whole length of transporting pipeline reaches more than 8.5km and the efficiency of the system and the characteristics of the flow are critical factors. The main parameters which govern the flow are flow-rate, velocity, concentration and slip-layer's condition, so in the field test monitoring system was applied to check the real time conditions of the closed circuit flow and the main parameters. From analyzing the relation between the dredged soil amounts and the pump power, it can be concluded that the magnetic forces effect on the transporting system, increase the transporting quantities of dredged soil and decrease power consumption of the pump.

Effect of File I/O on a coupled FEM & FVM solver (FEM 및 FVM solver 결합 이용에 대한 파일 I/O 의 영향)

  • Ko, Won-Jin;Lee, Ki-Taek;Yoo, Ji-Hyung;Jung, Hyung-Soo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2021.11a
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    • pp.423-425
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    • 2021
  • 전기 자동차 에너지 시스템을 개발하기 위해서는 열 유체-전자기장 연성해석이 필요하다. 이를 위해 열 유체와 전자기장 각각의 해석에 특화된 패키지들을 사용하고, 이 패키지의 실험 결과를 저장 장치를 통해 주고받는다. 하지만 이는 저장장치 I/O 횟수를 늘려서 전체 계산 과정을 느리게 만들 수 있다. 데이터 교환을 MPI 패키지를 이용하여 DRAM 을 통해 이루어지도록 만들 수 있지만, 이는 계산 결과의 지속성을 악화시킨다. 즉, 열 유체 및 전자기장 연산과정에서 속도와 결과의 지속성은 상충적인 관계 갖는다. 본 연구는 이러한 관계를 실험적으로 분석하고 데이터의 지속성을 완화했을 때 이에 의해 얻을 수 있는 성능 이익을 분석한다.

Electromagnetic Field Coupling of Small Metallic Cans in Mobile Devices (모바일 기기용 소형 금속 캔의 전자기장 결합 특성)

  • Park, Hyun Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.11
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    • pp.916-919
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    • 2017
  • This paper examines electromagnetic leakage path of small shield cans employed in mobile devices such as smart-phones by using numerical simulation and analyzes near-field coupling due to each of the leakage electric and magnetic fields by using IC-stripline method. From the results, it is confirmed that the leakage from the apertures or slots on the top of shield can is dominated by magnetic field, whereas the leakage from the seam on the side of shield can is mostly caused by electric field.

Analysis of Monostatic/Bistatic Radar Cross Section of Multi-target for Target Signals Simulation (항적 신호 모의를 위한 다기종 모노스태틱/바이스태틱 레이다반사면적 분석)

  • Park, Jun-Sik;Chi, Soung-Hwan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.5
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    • pp.789-798
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    • 2021
  • In this study, for the purpose of collecting and analyzing target-specific RCS data of target signals simulator for verification/improvement of radar system performance, VHF band monostatic/bistatic RCS of civil aircraft(B-747, B-737) and fighter(F-16) models were analyzed by EM simulation tool. In order to reduce the RCS analysis time, the analysis time and RCS data were compared and cross-verified. Also, the analysis range was selected by examining the interpolation error according to the analysis angle resolution. The RCS data obtained for each model were analyzed separately by the incident/reflection elevation angle and frequency. The RCS characteristics according to the shape of the aircraft and the incident/reflection azimuth angle were described. Finally, the statistical RCS distribution value of each model is presented through RCS distribution histogram analysis. In the future, the RCS database obtained by this study will be used for the target signals simulator of the VHF band radar system.