• 제목/요약/키워드: pulses

검색결과 1,596건 처리시간 0.031초

Study of Non-uniform Plasma Layer Variation with Optically-Controlled Microwave Pulses

  • Wang, Xue;Yun, Ji-Hun;Kim, Yong-K.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.90-91
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    • 2009
  • We study of the variation on non-uniform plasma in different layer of the semiconductor. The transient response in different plasma layer has been evaluated theoretically. The reflection function of dielectric microstrip lines resulting from the presence of plasma are evaluated by the transmission line model. The diffusion length is small compared to the absorption depth. The variation of characteristic response in plasma layer with microwave pulses which has in localized has been evaluated.

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Real-time Temporal Characterization and Performance Optimization of a kHz Femtosecond Ti:Sapphire Laser Using a Comprehensive SPIDER

  • Luu, Tran Trung;Park, Ju-Yun;Lee, Jae-Hwan;Nam, Chang-Hee
    • Journal of the Optical Society of Korea
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    • 제14권2호
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    • pp.146-151
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    • 2010
  • A comprehensive real-time spectral phase interferometry for direct electric field reconstruction (SPIDER) apparatus for characterizing femtosecond laser pulses is demonstrated. The SPIDER provides the temporal profiles of femtosecond laser pulses, reconstructed at the speed of 3.5 Hz, with parameters of the spectral phase such as group delay dispersion and third-order dispersion. The apparatus is applied successfully to optimize the spectral dispersion of a kHz femtosecond Ti:Sapphire laser by adjusting a grating compressor in real time.

AC PDP에서 불평형 Sustain Pulse를 이용한 휘도제어법 (Luminance Control by the asymmetric sustain pulse amplitude in ACPDP)

  • 최준영;김동현;이호준;박정후
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.33-35
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    • 2003
  • The luminance of at PDP has been controlled by the number of sustain pulses. Therefore, it is very difficult to control the luminance by sustain pulses for a given gray level. This paper deals with a new method to control the luminance by the sustain pulse amplitude in ac PDP. The suggested method can control the luminance by 60% without change of the number of sustain pulses.

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부분방전 교정펄스 발생기의 표준화 시스템구축과 불확도 (Setup and Uncertainty of Standard System for Calibrating Pulse Generator of Partial Discharge)

  • 김광화;이상화;이헌진;강동식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.1355_1357
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    • 2009
  • This paper describes the standard system for calibrating pulse generator of partial discharge(PD) and its uncertainty. The system is consisted of digital pulse generator, digital recorder and evaluation software. The uncertainty requirement of calibrator charge is less than $\pm$ (0.1pC + 0.03q) and that of pulse duration is less than $\pm$ 10 %. The system can generate various kind of calibration pulses such as single pulse, double pulses, oscillation pulse, long-duration pulse, random pulses and evaluate their uncertainty.

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전력선 주파수를 이용한 가시광 채널의 시분할 전송 (Time Division Transmission of Visible Light Channels Using Power Line Frequency)

  • 이성호
    • 센서학회지
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    • 제23권5호
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    • pp.349-355
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    • 2014
  • In this paper, we developed a new method to transmit multiple visible light channels in time division mode using the AC power line frequency in order to prevent the crosstalk between adjacent optical signals. Synchronizing pulses are generated from the 220 V power line, and one pulse period is subdivided into several time slots for visible light channels. Each channel transmits data in a predefined time slot without interfering adjacent channels. In experiments, synchronizing pulses with a repetition rate of 240 Hz were generated from the 60 Hz power line, and three VLC channels with a bit rate of 9.6 kbps transmitted data independently using the time slots between synchronizing pulses. This configuration is very useful in constructing time division VLC networks for multiple sensors.

방사선 펄스의 고안정 계측회로 설계 (Design of a High Stable Measuring Circuit for Radioactive Pulses)

  • 송재용;한주섭;천상규;길경석
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2000년도 추계종합학술대회
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    • pp.577-580
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    • 2000
  • The aim of this paper is to develop a high stable measuring device for radioactive pulses. The device consists of a high voltage supply unit using a fly-back converter principle, and a pulse detection unit for gamma-rays and neutrons. The high voltage supply unit designed can generate DC voltage up to 1,500v at 5V-input, and have a series voltage regulator to maintain the output voltage constantly, resulting in less than 1.63% of voltage regulation. The pulse detection parts consists of an active integrator, a pole-zero circuit, and a 3-stage amplifier of 60 dB, and its frequency bandwidth is from 37 Hz to 300 kHz. From the experimental results, it is confirmed that the measuring device can count at least 10,000 pulses in a second.

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인공적 침상보이드의 갭길이 변화에 따른 음향방출 특성 (Characteristics of acoustic emission according to variation gap length on artificial needle shape void)

  • 박재준;김상남
    • E2M - 전기 전자와 첨단 소재
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    • 제8권4호
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    • pp.495-503
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    • 1995
  • As lengthen gap leng of artificial needle shape void 0.24.rarw.1.5[mm]), the amplitude of AE(Acoustic Emission) pulses was enlarged and number of pulses be generated was few. The longer gap length of void, the shorter breakdown time. As a result of this, I found that existen of void in insulation mate was fatal deterioration of insulation. According to phase angle of applied voltage, time being void was scattered largely in region of phase angle of pulses of origination in phase angle of applied voltage. The result will be used to analysis of void diagnosis.

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LD gain-switching에 의한 초단 광 펄스 발생 해석 (Analysis of ultra-short optical pulse generation by LD gain-switching)

  • 김윤중;김동각;김창민
    • 전자공학회논문지D
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    • 제34D권10호
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    • pp.85-92
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    • 1997
  • For a InGaAsP buried - heterostructrue $1.3\mu\textrm{m}$ LD with fabry-perot cavity structure, the procedures of ultra-short optical pulse genration ar eanalyzed by simulating the rate equations. Investigting the effects of injected current pulse parameters such as bias $J_b$, pulse width $T_d$ and pulse amplitude $J_p$ on the generated optical pulses, we derive the optimum conditions to obtain a single optical pulse with strong peak value. We also observe that the repetition rate of current pulses needs to be restricted under a certain threshold to generate a train of single optical pulses, and that the period doubling phenomenon takes place by increasing the repitition rate.

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Sustain Discharge Mode Assisted by Various Auxiliary Pulses in AC PDP

  • Cho, Byung-Gwon;Tae, Heung-Sik;Chien, Sung-Ii
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.113-116
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    • 2003
  • The sustain discharge mode using various auxiliary pulses was proposed to improve both the luminance and luminous efficiency of ac-plasma display panel (ac-PDP). It was found that the various auxiliary pulses, which were applied at the rising and falling time of the sustain pulse, played a role in strengthening both the main and self-erasing discharges. As a result, the sustain waveforms with auxiliary pulse improved both the luminance of 23 % and the luminous efficiency of 36 %, when compared with the conventional sustain waveform without auxiliary pulse.

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AlGaAs 진행파 반도체 레이저 광증폭기의 모드록킹 (Mode Locking of AlGaAs Semicondctor Laser Traveling Wave Amplifiers)

  • 이창희;강승구;정기웅;임시종;유태경
    • 전자공학회논문지A
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    • 제32A권1호
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    • pp.119-128
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    • 1995
  • We report hybrid and passive mode-locking results of tilted-stripe AlGaAs semiconductor laser traveling wave amplifiers with saturable absorbers. Dependence ofthe pulse width on the mode locking frequency, the bandwidth of spectral filters, and the bias current of the laser amplifier are investigated. We generate 4 ps optical pulses by using the hybrid mode locking technique. The repetition rate and the peak power of generated pulses are 516 MHz and 170 mW, respectively. The tuning range of uor mode locked laser is 10 nm with the center wavelength of 780 nm. We also generate 2.6 ps optical pulses with peak power of 830 mW by using the passive mode locking technique.

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