• 제목/요약/키워드: repetition maximum

검색결과 146건 처리시간 0.023초

A Study on the Adjusting Output Energy of the $CO_2$ Laser Controlled Directly in AC Power Line

  • Noh, Ki-Kyong;Jeong, Jong-Jin;Chung, Hyun-Ju;Kim, Hee-Je
    • KIEE International Transactions on Electrophysics and Applications
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    • 제5C권4호
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    • pp.152-154
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    • 2005
  • We demonstrate a simple $CO_2$ laser by controlling firing angle of a TRIAC switch in ac power line. The power supply for our laser system switches the voltage of the AC power line (60Hz) directly. The power supply does not need elements such as a rectifier bridge, energy-storage capacitors, or a current-limiting resistor in the discharge circuit. In order to control the laser output power, the pulse repetition rate is adjusted up to 60Hz and the firing angle of TRIAC gate is varied from $45^{circ}$ to $135^{circ}$. A ZCS(Zero Crossing Switch) circuit and a PIC one-chip microprocessor are used to control the gate signal of the TRIAC precisely. The maximum laser output of 40W is obtained at a total pressure of 18 Torr, a pulse repetition rate of 60Hz, and a TRAIC gate firing angle of $90^{circ}$.

High Repetition Rate Optical Pulse Multiplication with Cascaded Long-period Fiber Gratings

  • Lee, Byeang-Ha;Eom, Tae-Joong;Kim, Sun-Jong;Park, Chang-Soo
    • Journal of the Optical Society of Korea
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    • 제8권1호
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    • pp.29-33
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    • 2004
  • We propose and demonstrate a novel optical pulse multiplier applicable to OTDM (Optical Time Division Multiplexing) systems using cascaded long-period fiber gratings. We have exploited the fact that each mode in a fiber has a different propagation constant to obtain time delays among optical pulses. The proposed scheme could realize high-frequency optical pulse multiplication for optical short pulse trains. We have successfully implemented two, four, and eight times multiplications with the maximum repetition rate of 416.7 ㎓. The obtained pulse delays are well matched with the simulated ones.

Nd:YLF 레이저 펄스의 재생식 증폭 (Regenerative amplification of pulses in Nd:YLF)

    • 한국광학회지
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    • 제3권1호
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    • pp.37-42
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    • 1992
  • 공진기 내에서 종자펄스를 여러번 왕복시키며 증폭시키는 재생식 증폭기의 설계 및 동작톡성에 대하여 연구하였다. 기계적, 열적 요동에 대하여 안정된 작동을 하도록 Nd:YLF를 레이저 매질로 사용하고, 광학 부품에 미치는 에너지 밀도를 최소화할 수 있도록 오목거울과 볼록거울로 구성된 증폭기 공진기를 설계, 제작하였다. 종자펄스로는 펄스 폭 40ps, 에너지 100pJ, 파장 1,053.$\mu$m인 Nd:YLF 레이저 펄스를 사용하여 재생식 증폭기로 최대 반복률 3.5kHz에서 1mJ의 안정된 펄스를 얻었으며, 최대 출력은 5mJ이었다.

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10kV 고 반복률 펄스 전원장치 (10kV High Repetitive Pulsed Power Generator)

  • 조현빈;송승호;장성록;류홍제
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2019년도 전력전자학술대회
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    • pp.171-173
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    • 2019
  • In this paper, 10kV solid-state pulsed power modulator with high repetition rate is described. The modulator is based on a Marx generator that charges capacitors in parallel and discharges them in series. Twelve IGBTs and capacitors are connected in series to generate output voltages up to 10kV at a repetition rate of 100kHz. The volume of the modulator is 26.1 liters, and its maximum average output power is 10kW. Therefore, the compact design is achieved with a high power density of 380 W/L. Finally, it is confirmed that the pulsed power modulator can operate stably through the experiment results at 10kV 100kHz condition.

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Co-Channel Interference Cancellation in Cellular OFDM Networks PART II: Co-Channel Interference Cancellation in Single Frequency OFDM Networks using Soft Decision MLE CCI Canceler

  • Mohaisen, Manar;Chang, Kyung-Hi
    • 한국통신학회논문지
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    • 제32권7A호
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    • pp.710-716
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    • 2007
  • 본 논문에서는 OFDM 셀룰라 네트워크에서 셀 가장자리에 위치한 사용자를 위한 다운링크 동일채널간섭(CCI) 제거 기법을 소개한다. 기지국간의 협력적 심볼 전송은 동일 심볼을 다른 기지국에서 상이한 부반송파를 사용하여 전송함으로서 이루어진다. 단말기에서는 전송된 심볼을 추정하기 위하여 연판정 최대우도 동일채널간섭 제거기(soft decision maximum likelihood CCI canceler)와 수정된 최대비 합성법 (modified maximum ratio combining (M-MRC))을 적용하며, 합성법에 사용된 가중치는 협력 기지국과 단말기 사이의 채널 상수에 의해서 유도된다. 시뮬레이션 결과로부터 제안된 기법이 주파수 선택적 페이딩 채널과 주파수 비선택적 페이딩 채널에서 각기 9 dB와 6dB의 SIR 이득을 보임을 알 수 있다.

여수세계박람회와 지역문화의 융합을 기반으로 한 패션문화상품 디자인개발 (Design Development of Fashion Cultural Products based on Convergence of International Exposition Yeosu and Regional Culture)

  • 김선영
    • 복식
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    • 제61권1호
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    • pp.58-68
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    • 2011
  • With Expo 2012 Yeosu to be held in 2012, this study intends to propose designs for fashion cultural products into which the characteristics of local cultures of Yeosu are fused. Using symbols of Expo 2012 Yeosu and cultural symbols of Yeosu City as motifs, this study will develop patterns and then, apply them to neckties, handkerchiefs, and T-shirts. Adobe Illustrator CS2 and Adobe Photoshop CS2 will be used. This study developed basic motifs so that cultural resources using camellia, Odong Island, and the Turtle Ship, which represent Yeosu City, could be well harmonized with the topic of Expo 2012 Yeosu. This paper set three basic motifs of new formative images, using graphic images that were made by omission of forms, simplification, overlap, repetition, and calligraphy of the name of Yeosu holding the event. Each set motif was expanded to three motifs again through change, conversion, and mixture of colors, and three types of repetitive applied patterns were developed through revolution, symmetry, repetition, and reversal of each motif. The modern and refined image for neckties, to which the developed motif was applied, was made by directly applying the repetitive pattern of each motif or by making $45^{\circ}$ revolution. For handkerchiefs, revolution, enlargement, reduction, and gradation were applied to the motif so the pattern could be highlighted to the maximum and finally, a colorful image was developed. For T-shirts, three designs-a half-sleeved box type, a sleeveless round neckline type, and a sleeveless V-neckline tight type-were developed, through which availability of the design was increased. Through enlargement, reduction, revolution, and repetition of each motif, this paper layout the pattern on the whole part of a T-shirt, pursuing a decorative and casual image.

링 블로우를 이용한 펄스형 $CO_2$ 레이저 시스템의 효율 향상과 동작 특성에 관한 연구 (A Study on Efficiency Improvement and Optimization of Operating Characteristics of Pulsed $CO_2$ Laser System using Ring Blower)

  • 김도완;정현주;박성준;정종한;이동훈;김희제;조정수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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    • pp.57-60
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    • 2000
  • In this paper, it is purpose to develop a pulsed $CO_2$ laser with stable output at pulse repetition rate range of 2 KHz. We used a IGBT as a switching device. The laser cavity was fabricated as an axial and water cooled type. It was used a ring blower to increase a cooling effect The laser performance characteristics as parameters, such as pulse repetition rate, gas pressure have been investigated. The experiment was done under 3 electrode-type instead of 2 electrode-type. To achieve 3 electrode-type, we used two pulse-transformers which is operated parallel. As a result, the maximum output was about 28 W at the total pressure of 20 Torr, the gas mixture $Co_2$:$N_2$:He=1:9:15 and the pulse repetition rate of 1300 Hz.

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위상각와 주파수 제어에 따른 상용주파 AC 여기 방식의 펄스형 $CO_2$ 레이저 전원장치 개발에 관한 연구 (Output characteristics of ac excited $CO_2$ laser as a adjusting a phase angle and frequency)

  • 정현주;김도완;이동훈;김중만;김희제;조정수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.2098-2100
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    • 2000
  • We propose pulsed $CO_2$ laser below 30W by the AC(60Hz) switching control of leakage transformer primary which has some advantage of cost and size compared to a typical pulsed power supply. Pulse repetition rate is adjusted from 5Hz to 60Hz to control laser output. In this laser, a low voltage open loop control for high voltage discharge circuit is employed to avoid the HV sampling or switching and high voltage leakage transformer is used to convert rectified low voltage pulse to high voltage one. A ZCS(Zero Cross Switch) circuit and a PIC one-chip microprocessor are used to control gate signal of SCR precisely. The pulse repetition rate is limited by 60Hz due to the frequency of AC line and a high leakage inductance. The maximum laser output was obtained about 23W at pulse repetition rate of 60Hz, total gas mixture of $CO_{2}/N_{2}$/He = 1/9/15, SCR gate trigger angle 90$^{\circ}$, and total pressure of 18Torr.

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3전극 방식과 링 블로우를 이용한 펄스형 $CO_2$ 레이저 시스템의 효율 향상과 동작 특성에 관한 연구 (A Study on Efficiency Improvement and Optimization of Operating Characteristics of Pulsed $CO_2$ Laser System using 3 Electrode-type and Ring Blower)

  • 김도완;정현주;박성준;이유수;이동훈;김희제;조정수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.2101-2103
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    • 2000
  • In this paper, it is purpose to develop a pulsed $CO_2$ laser with stable output at pulse repetition rate range of 2 kHz. We used a IGBT as a switching device. The laser cavity was fabricated as an axial and water cooled type. It was used a ring blower to increase a cooling effect. The laser performance characteristics as parameters, such as pulse repetition rate, gas pressure have been investigated. The experiment was done under 3 electrode-type instead of 2 electrode-type. To achieve 3 electrode-type, we used two pulse-transformers which is operated parallel. As a result. the maximum output was about 28 W at the total pressure, of 20 Torr(the gas mixture $CO_2$:$N_2$:He=1:9:15 and the pulse repetition rate of 1300 Hz).

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상용교류방전 자기자극장치의 동작특성 (Commercial frequency AC discharge magnetic stimulation operating characteristics)

  • 김휘영
    • 한국정보통신학회논문지
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    • 제13권12호
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    • pp.2685-2692
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    • 2009
  • 펄스형 자기자극장치를 누설변압기의 1차측 스위칭 제어로 교류(60hz) 스위칭 제어를 하여 비용과 크기면에서 기존의 전원장치로 구성된 것보다 약30w의 소용량으로 구성을 할 수가 있었다. 펄스반복률은 자기자극장치의 출력제어를 5-60hz로 적절하게 조절하였다. 이 자석 자극에서는, 고전압 출력 회로를 위한 낮은 전압 열리는 반복 통제가 고전압 표본 추출을 피하기 위하여 채택되며, 또는 스위칭제어와 고전압 누설 변압기는 고전압 하나로 조정된 낮은 전압 펄스를 개조하기 위하여 사용된다. ZCS (영전류스위칭) 회로 및 DSP & FPGA는 SCR의 게이트 신호를 정확하게 통제하기 위하여 사용된다. 펄스 반복 비율은 AC 선과 높은 누설 유도자의 주파수 때문에 60Hz에 의해 제한된다. 최대 자석자극장치의 출력은6 0Hz, 각각 40, 80, 120, $160^{\circ}$, SCR 게이트의 펄스반복 비율로 33W에 관하여 트리거 각 $90^{\circ}$에 대한 전체적인 출력으로 얻어졌다.