• 제목/요약/키워드: pulse period

검색결과 570건 처리시간 0.032초

흡수격자를 갖는 DFB 레이저의 제작 및 특성 (Fabrication and Characteristics of DFB Laser with Absorption Grating)

  • 이형종
    • 한국광학회:학술대회논문집
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    • 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
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    • pp.73-78
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    • 1990
  • 1.3${\mu}{\textrm}{m}$ DFB with absorption grating of 1.55${\mu}{\textrm}{m}$ InGaAsP layer was fabricated. This new type of DFB laser shows self-plusation for DC operation. At low level of injection the relation between the pulsation frequency and the injection current shows similar behavior with the relaxation oscillation of ordinary laser and at high level of injection the pulsation frequency decreases compared to the relaxation oscillation. Period doubling, period 3 and 4 were observed for AC modulation. In case of period doubling the waveform shows only one pulse within a period without any accompanying subsidiary pulses and the oscillation frequency was quite stable. The pulse widths as short as 58.5 ps was achieved with AC modulation. We propose the time division multiplexing application of this kind of DFB laser.

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음식섭취에 따른 좌우(左右) 촌관척(寸關尺) 6부위 맥파의 주파수 분석 (A Study on the Effect of Food Intake on Radial Pulse using Fourier Analysis)

  • 임윤경;박광석
    • 대한한의학회지
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    • 제32권4호
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    • pp.139-148
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    • 2011
  • Objective: The purpose of this study was to investigate the effect of food intake on the Fourier components of radial pulse wave. Methods: Thirty-one healthy male subjects participated in this study. Radial pulse was measured using 3 dimensional pulse imaging system (DMP-3000) before, right after, 40 minutes after, 80 minutes after and 120 minutes after food intake. Fourier transform was performed and the frequency and amplitude of Fourier components were analyzed. Results: 1. The frequency and the amplitude of Fourier components of radial pulse wave increased significantly after food intake. 2. The frequency of Fourier components increased right after food intake and then gradually decreased as time passed, however the amplitude of Fourier components increased and maintained certain levels and patterns throughout the experimental period of 120 minutes. 3. The change ratios of the frequency and the amplitude of Fourier components after food intake varied with the pulse measuring locations. Conclusions: Food intake exerts an influence on radial pulse wave, resulting in increase of frequency and amplitude of Fourier components. The change ratios of the frequency and the amplitude of Fourier components after food intake varied with the pulse measuring locations.

3D Blood Pressure Pulse Analyzer로 측정한 맥파 에너지와 산후 부종과의 상관성 연구 (Correlations between Postpartum Edema and Pulse Energy Measured by 3D Blood Pressure Pulse Analyzer)

  • 이지연;윤영진
    • 대한한방부인과학회지
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    • 제27권1호
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    • pp.167-175
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    • 2014
  • Purpose: This study was performed to find correlations between Edema Index and Pulse Energy in early postpartum period. Methods: Fiftynine postpartum women were participated in this study which was conducted with Inbody 720 (Biospace Co. Ltd) and 3D Blood Pressure Pulse Analyzer (3D-MAC). Edema Index (Extra Cellular Water/Total Body Water) calculated after body composition analysis and 3D-MAC result (Pulse Energy) were analysed within a week after delivery. Results: The results were as follows 1. Edema Indexes of the upper, lower limbs, trunk and whole body were associated with each other respectively. 2. Edema Indexes and Right Kwan pulse energy had significant positive correlation. 3. Right Kwan pulse energy showed positive correlations with Left Kwan, Right Chon, Right Cheok. Conclusions: Viscera associated with Postpartum Edema are Spleen, Lung, Liver and Vital Gate. The most important thing is thought to be Spleen.

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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Design and Simulation a New Unique-Slit Reticle for Pulsed Infrared Seekers

  • Yasin, Sair Alcekh;Erfanian, Ali Reza;Mosavi, Mohammad Reza;Mohammadi, Ali
    • Journal of the Optical Society of Korea
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    • 제18권1호
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    • pp.1-8
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    • 2014
  • Spin reticle infrared seekers have good linearity, and the pulse-modulated reticle seekers have good digital characteristics for anti-jamming processing. A basic design for a spin pulse-modulated reticle is introduced. This design uses the rotating design of the optical system in the spin infrared seekers and an improved design of the reticle in the pulse-modulated seekers. The reticle contains a unique well-designed slit to produce one pulse for each target in the spinning period. The target data will be carried by the unique pulse parameters. A simulation tool is implemented using the MATLAB packages for analyzing and evaluating the new design.

A New High-Voltage Generator for the Semiconductor Chip

  • Kim Phil Jung;Ku Dae Sung;Chat Sin Young;Jeong Lae Seong;Yang Dong Hyun;Kim Jong Bin
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 학술대회지
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    • pp.612-615
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    • 2004
  • A high-voltage generator is used to program the anti-fuse of the semiconductor chip. A new high-voltage generator consists of PN diodes and new stack type capacitors. An oscillator supply pulses to the high-voltage generator. The pulse period of the oscillator is delayed by controlling gate-voltage of the MOS. The pulse period is about 27ns, therefore the pulse frequency is about 37MHz. The threshold voltage of PN diode is about 0.8V. The capacitance of new stack type capacitor is about 4pF. The output voltage of the new high-voltage generator is about 7.9V and its current capacity is about $488{\mu}$A.

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An Empirical Study on the Application of Lead-Acid Batteries to ESSs and Performance Improvement Methods

  • Jung, Hyun-Chul;Heo, Hoon
    • Journal of Power Electronics
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    • 제15권5호
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    • pp.1295-1304
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    • 2015
  • In this paper, an approach to extend the life of lead-acid batteries through the elimination of sulfation with "rest time" using the pulse current of a conventional DPV (Differential Pulse Voltammetry) method is discussed. A new rest time without "0" current in "saw-tooth" pattern pulses is proposed to overcome the "0" current (blackout period), which is a shortcoming of DPV. This will enable the proposed method to be used in the loaded state. In the proposed approach, ESSs (Energy Storage Systems) were discharged for 5 h twice per day for 6 months on weekdays. To observe the changes in the lifespan of the systems, for the same period, the changes in the impedances of lead-acid batteries which were being charged e without charging and discharging were measure and compared. This study is focused on determining the effectiveness of lead-acid batteries as ESSs.

Improved Waveform during the Addressing Period for the Improvement of the Addressing Time for AC PDPs

  • Lim, Jong-Sik;Kim, Hyun-Seok;Kim, Joon-Yub
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.511-514
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    • 2004
  • ADS(Address Display period Separation) driving method has been considered to be the most appropriate driving technique for AC PDPs. However when the ADS driving method is applied to the high-resolution AC PDP, the required long addressing time often becomes a problem. In this paper, we present a new waveform for reducing the addressing time and for the stable addressing discharge. In this new waveform, a wall charge acceleration pulse is applied to the common electrode right after 80us scan time. In this way, the charge generated by the addressing discharge is accelerated to the electrodes. Experiments using the wall charge acceleration pulse showed that we could stably address an AC PDP with the scan pulses having pulse width of 1 us

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Effect of auxiliary electrode on the discharge characteristics in AC PDP with long sustain-gap

  • Park, Sang-Dae;Lee, Seung-Hun;Shin, Nam-Hoon;Lee, Kyo-Sung;Park, Sung-Yun;Kim, Sang-Ho;Shin, Bhum-Jae;Choi, Kyung-Cheol
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.109-112
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    • 2004
  • The effect of auxiliary electrode on the discharge characteristics in AC PDP with long sustain-gap was investigated. The auxiliary electrode was placed between scan and common electrode. When the pulse was applied to the auxiliary electrode during sustain period, the luminance of Ne + 13%Xe gas-mixture discharge increased and the discharge current decreased. The auxiliary pulse plays a role of improving electron excitation efficiency. When the auxiliary pulse was applied during address period, the address discharge time lag of Ne + 13%Xe gas-mixture could be reduced remarkably.

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Modified Ramp Reset Waveform for High Contrast Ratio in AC PDPs

  • Kim, Jae-Sung;Yang, Jin-Ho;Ha, Chang-Hoon;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.199-202
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    • 2002
  • In general, the background light produced during the reset period deteriorates the dark room contrast ratio in AC PDP. In this paper, we propose a modified ramp reset pulse that can reduce the background light to imperceptible level. In the new reset waveform, the discharges between the scan and sustain electrodes are minimized by applying a positive bias voltage to the sustain electrode and only the weak discharges between the scan and address electrodes occur during the reset period. We adopted a MgO coated phosphor layer to get the same level of voltage margin in the new reset pulse scheme compared to that of the conventional ramp reset pulse one. As a result, the voltage margin is maintained at the same level and the dark room contrast ratio is improved dramatically.

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