• 제목/요약/키워드: EM

검색결과 2,400건 처리시간 0.029초

초고속 자기부상열차 적용을 위한 초전도 하이브리드 전자석 시작품의 설계 (Design of Prototype Superconducting Hybrid Electromagnet for High Speed Maglev)

  • 이창영;강부병;조정민;한영재;주승열;황영진;조현철;장재영;고태국
    • 한국초전도ㆍ저온공학회논문지
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    • 제13권3호
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    • pp.1-4
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    • 2011
  • This paper deals with the design and fabrication of prototype superconducting hybrid electromagnet(SH-EM) for EMS (Electromagnetic suspension)-based Maglev. The design requirements are based on the normal conducting EM used in the German high-speed Maglev. From the MMF-Levitation force curves simulated by FEM analysis, the required MMF by superconducting coil is suggested. As an experimental test setup to demonstrate the SH-EM, the experimental SH-EM with HTS coil cooled in $LN_2$ is fabricated. From the expected operating current of the HTS coil, the levitation performance of the SH-EM is estimated.

옥상 저류조 설치에 따른 최상층 실내열환경 변화에 관한 모형 실험연구 (The Variation of Top Floor Indoor Thermal Environment with Roof Storage Using Model Experiment)

  • 박봉길;이경희;장승재
    • 한국주거학회논문집
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    • 제20권3호
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    • pp.105-112
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    • 2009
  • The purpose of this study is to investigate a top floor, indoor, thermal environment by comparison between the indoor air temperature and the rooftop surface temperature, and between the indoor air temperature and the outdoor air temperature using an experimental model. The model experiment was conducted with 4 cases,: no-rainfall, 1 em-height, 10 em-height and 20em-height of rainfall on the rooftop. According to the results of the height of stored rainfall, the average air temperature difference between the indoor and outdoor air with 1, 10 and 20 em-height of rainfall on the rooftop was $4.0^{\circ}C$, rooftop $1.2^{\circ}C$ and rooftop $1.0^{\circ}C$, respectively. The upper 10 em-height of rainfall on the rooftop acted to decrease the indoor air temperature on the top floor.

선박용 레이다의 허상 방지용 PAINT형 전파흡수체의 개발 (Development of Paint-type EM Wave Absorbers for Radar Used in Ships)

  • 정재현;김동일;송재만;최정현
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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    • pp.423-428
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    • 2005
  • We prepared paint-type and sheet-type EM wave absorbers with Mn-Zn Ferrite, Ni-Zn Ferrite, Ba Ferrite, Sr Ferrite, and Sendust against ghosts of a mater in ships. To prepare the absorbers, enamel paint and epoxy paint were used as binders. The prepared EM wave absorber's absorption properties were investigated. The prepared EM wave absorbers have 6 dB over in 2 GHz ${\sim}$ 4 GHz. We compared properties of wave absorption between paint-type and spray-type

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960MHz 대역 다층구조 VCO 설계 (960MHz band multi-layer VCO design)

  • 이동희;정진휘
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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    • pp.410-413
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    • 2001
  • In this paper, we present results of this that design of the multi-layer VCO(Voltage Controlled Oscillator), which is composed of the resonation circuit and the oscillation circuit, using EM simulator and nonlinear RF circuit simulator. EM simulator is used for acquiring EM(Electromagnetic) characteristics of conductor pattern as well as designing multi-layer VCO, Acquired EM characteristics of the circuit pattern was used like real components at nonlinear RF circuit simulator. Finally VCO is simulated at nonlinear RF circuit simulator. The material for the circuit pattern was Ag and the dielectric was DuPont #9599, which is applied for L TCC process. The structure is constructed with 4 conducting layer. Simulated results showed that the output level was about 1[dBm], the phase noise was 102 [dBc/Hz] at 30[kHz] offset frequency, the harmonics -8dBc, and the control voltage sensitivity of 30[MHz/V] with a DC current consumption of l0[mA]

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GHz 대역용 복합형 Ba 페라이트 전파흡수체의 개발 (Development of Composite Ba Ferrite EM Wave Absorbers for GHz Frequency)

  • 문상현;신승재;송재만;김동일;김기만
    • 한국전자파학회논문지
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    • 제14권12호
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    • pp.1329-1334
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    • 2003
  • 폐 처리된 Ba 페라이트를 사용하여 GHz 대역용 전파흡수체를 개발하였다. 도전 손실재인 카본의 첨가에 따른 전파흡수능의 변화와 시편 제작시 제작온도 변화에 따른 전파흡수능의 변화를 조사하였다. 이와 같은 실험을 통하여 GHz 대역용 Ba 페라이트 전파흡수체를 개발하는데 있어 카본의 첨가가 매우 유효함을 알았으며, 시편의 제작온도 또한 우수한 전파흡수체를 개발하는데 있어 반드시 고려되어야 함을 밝혔다.

포켈스 효과를 이용한 불평등 전계 측정 (A possible application of the nonuniform electric field measurement using Pockets effect)

  • 강원종;임윤석;최재옥;장용무;구자윤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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    • pp.513-515
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    • 2000
  • In this paper, new Partial Discharge (PD) detection technique using Pockels-cell was proposed. For this purpose, PD was generated from needle-plane electrode in air and detected by optical measuring system using Pockets cell, based on Mach-Zehnder interferometer, consisting of He-Ne laser, single mode optical fiber, 50/50 beam splitter and photo detector. We show the characteristic of the proto-type sensor for the corona discharge.

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응급의학은 어떤 의학분야이며 그 미래는? (What is Emergency Medicine and Its Agenda for Future)

  • 도병수;이삼범
    • Journal of Yeungnam Medical Science
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    • 제19권2호
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    • pp.92-98
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    • 2002
  • Emergency medicine(EM) is the specialty of evaluating, stabilizing and initiating treatment for patients with life or limb-threatening illnesses or injuries. Techniques unique to the specialty of EM are the triage systems, quick stabilization methods, and emergency surgery procedures. The field of EM encompasses areas such as emergency department management, disaster planning and management, the management of emergency medical service(EMS) systems, research into such areas as brain and heart resuscitation, trauma and disaster management, survival medicine, and environmental emergencies(cold and heat injuries, poisioning, decompression sickness and barotrauma). Today, in addition to providing emergency care, the emergency specialists have moral and legal obligations to assess and report probable cases of child and spouse abuse, sexual assault, and alcohol and drug abuse. Future, the EM should provide surveillance, identification, intervention, and evaluation of injury and disease, therefore EM will remain as a key component of evolving community health care system.

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EM 알고리즘을 이용할 재귀적인 음소분리 (Recursive Segmentation of Speech Signals using Expectation-Minimization)

  • 강병옥;정홍
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 2002년도 하계학술발표대회 논문집 제21권 1호
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    • pp.103-106
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    • 2002
  • 본 논문에서는 입력음성신호로부터 음소간의 경계를 찾는 문제를 풀기위해 재귀적인 방식으로 EM 알고리즘을 적용한다. 즉, 예상되는 두 끝점 사이의 부분을 현재의 프레임 n 이라고 하면, 그 전 프레임 n-1 에서 구해진 끝점이 주는 정보와 그 끝점으로부터 이어지는 음성샘플로부터 현재 프레임의 끝점을 구한다. 또한 현재의 프레임 n 에서 끝점을 추정해 내면, 그 추정한 끝점과 그 점 이후에 이어지는 음성샘플값으로부터 다음 프레임 n+1 의 끝점을 구한다. 이러한 방식을 재귀적인 음소분리 방식이라고 한다. 그리고, 각 프레임에서 끝점을 구하기 위해서는 끝점의 좌표를 추정해야 할 파라메터로 하고, 그 주변의 음성샘플 값을 관찰 값으로 하여 EM(Expectation and Maximization) 알고리즘을 이용한다. 이 EM 알고리즘을 이용한 재귀적인 음소분리 방식을 실제 음성 DB 로부터 음소쌍을 추출하여 테스트 했을 때 약 5 회의 EM 반복 후에 경계간으로 수렴함을 볼 수 있었다.

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Broad-Band Design of Ferrite One-body EM Wave Absorbers for an Anechoic Chamber

  • Kim, Dong-Il;Son, June-Young;Park, Woo-Keun;Park, Dong-Han
    • Journal of electromagnetic engineering and science
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    • 제4권2호
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    • pp.51-55
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    • 2004
  • With the progress of the electronics industry and radio communication technology, certain problems, such as electromagnetic interference(EMI), have arisen due to the increased use of electromagnetic(EM) waves. International organizations such as CISPR, FCC, and ANSI have provided the standards for the EM wave environment and for the countermeasure of the electromagnetic compatibility(EMC). EM wave absorbers are used for constructing an anechoic chamber to test and measure EMI and electromagnetic susceptibility(EMS). In this paper, we have designed an one-body EM(electromagnetic) wave ferrite absorber, based on the equivalent material constants method for both normally and obliquely incident waves, whose absorption abilities are superior to that of the conventional ones. The fabricated absorber has a thickness of 27.68 mm and shows an absorption ability over 20 ㏈ in the frequency from 30 MHz to 6 ㎓.

960MHz대역 다층구조 VCO 설계 (960MHz band multi-layer VCO design)

  • 이동희;정진휘
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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    • pp.410-413
    • /
    • 2001
  • In this paper, we present results of this that design of the multi-layer VCO(Voltage Controlled Oscillator), which is composed of the resonation circuit and the oscillation circuit, using EM simulator and nonlinear RF circuit simulator. EM simulator is used for acquiring EM(Electromagnetic) characteristics of conductor pattern as well as designing multi-layer VCO, Acquired EM characteristics of the circuit pattern was used like real components at nonlinear RF circuit simulator. Finally VCO is simulated at nonlinear RF circuit simulator. The material for the circuit pattern was Ag and the dielectric was Dupont #9599, which is applied for LTCC process. The structure is constructed with 4 conducting layer. Simulated results showed that the output level was about 1[dBm], the phase noise was 102 [dBc/Hz] at 30[kHz] offset frequency, the harmonics -8dBc, and the control voltage sensitivity of 30[MHz/V] with a DC current consumption of 10[mA].

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