• 제목/요약/키워드: Avalanche

검색결과 217건 처리시간 0.027초

LDD 방식에 의한 Short 채널 MOSFET의 특성

  • 권상직;권오준
    • ETRI Journal
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    • 제8권4호
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    • pp.103-109
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    • 1986
  • LDD(Lightly Doped Drain) 방식에 의한 MOSFET의 제조 공정 및 특성에 관하여 실험 분석하였다. MOS 소자의 채널 길이가 짧아짐에 따라 드레인 가장자리에서 자체 형성되는 높은 전계로 말미암아 애벌런치 항복 전압(avalanche breakdown voltage)이 상당히 감소 한다. 이 전압을 높여 주기 위한 기술로서 LDD 방식이 적용되었으며 종래의 제조방식에 의한 MOSFET와 비교 기술되었다.

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PLCM을 이용한 카오스 블록 암호화 (Chaotic Block Encryption Using a PLCM)

  • 신재호;이성우
    • 전자공학회논문지CI
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    • 제43권3호
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    • pp.10-19
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    • 2006
  • 본 논문에서는 동력학적 특성이 좋은 PLCM(Piecewise Linear Chaotic Map)을 이용한 128비트의 키와 128비트 평문 블록의 카오스 블록 암호화 기법을 제안한다. 본 논문에서 제안한 기법은 128비트의 키를 PLCM을 이용해서 4개의 32비트 서브키로 이루어진 세션 키 생성하는 키 생성과정과 128비트 평문을 4개로 나눈 32비트 서브 블록들과 4개의 서브키와의 XOR(exclusive-OR)된 값을 PLCM의 초기 값과 반복회수로 사용해서 암호문을 생성하는 암/복호화 과정으로 이루어져 있다. 본 논문에서는 제안한 기법이 실험 결과와 안전성 분석을 통해 여러 가지 통계적 공격에 매우 강하고 Avalanche Effect와 Randomness 특성이 매우 좋음을 보여준다.

극초단 펄스 레이저에 의한 절연체의 광학 손상 해석 (Numerical Analysis of Optical Damage in Dielectrics Irradiated by Ultra-Short Pulsed Lasers)

  • 이성혁;강관구;이준식;최영기;박승호;유홍선
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.1213-1218
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    • 2004
  • The present article reports extensive numerical results on the non-local characteristics of ultra-short pulsed laser-induced breakdowns of fused silica ($SiO_{2}$) by using the multivariate Fokker-Planck equation. The nonlocal type of multivariate Fokker-Planck equation is modeled on the basis of the Boltzmann transport formalism to describe the ultra-short pulsed laser-induced damage phenomena in the energy-position space, together with avalanche ionization, three-body recombination, and multiphoton ionization. Effects of electron avalanche, recombination, and multiphoton ionization on the electronic transport are examined. From the results, it is observed that the recombination becomes prominent and contributes to reduce substantially the rate of increase in electron number density when the electron density exceeds a certain threshold. With very intense laser irradiation, a strong absorption of laser energy takes place and an initially transparent solid is converted to a metallic state, well known as laser-induced breakdown. It is also found that full ionization is provided at intensities above threshold, all further laser energy is deposited within a thin skin depth.

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Flow models of fluidized granular masses with different basal resistance terms

  • Wu, Hengbin;Jiang, Yuanjun;Zhang, Xuefu
    • Geomechanics and Engineering
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    • 제8권6호
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    • pp.811-828
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    • 2015
  • Proper modelling of the basal resistance terms is key in simulating the motion of fluidized granular flow. In this paper, standard depth-averaged governing equations of granular flow are used together with the classical Coulomb, Voellmy, and velocity dependent friction models (VDFM). A high-resolution modified TVDLF method is implemented to solve the partial differential equations without numerical oscillations. The effects of basal resistance terms on the motion of granular flows such as geometric shape evolution, travel times and final deposits are analyzed. Based on the numerical results, the predictions of the front and rear end positions and developing length of granular flow with Coulomb friction model show excellent agreements with experiment results reported by Hutter et al. (1995), and illustrate the validity of the numerical approach. For the Voellmy model, the higher value of turbulent coefficient than reality may obtain more reasonable predicted runout for the small-scale avalanche or granular flow. The energy exchange laws indicate that VDFM is different from the Coulomb and Voellmy models, although the flow characteristics of both three models fit the measurements and observations very well.

고정밀 레이저 변위기용 반사 광량 측정 기법 (The Measurement Method of Reflected Intensity of Radiation for High Precision Laser Range Finder)

  • 배영철;조의주;이현재;김성현;김현우
    • 한국항행학회논문지
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    • 제13권1호
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    • pp.34-40
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    • 2009
  • 고정밀 레이저 변위기에서 측정하고자하는 목표물인 표적으로부터 반사되어 돌아오는 반사광의 강도에 따라 애벌런치 포토다이오드(APD: Avalanche Photo Diode) 출력신호의 위상 지연이 발생한다. 이 위상지연에 의한 차이는 측정오차의 주요 원인이 되나 이를 측정하기 위한 적절한 계측기와 측정 방법이 없었다. 본 논문에서는 이들 문제를 해결하기 위하여, APD의 수신회로에 반사광량에 비례하는 출력 DC 전압을 측정하여 실시간으로 반사광의 강도를 측정할 수 있는 광량 측정기법을 제시하고 구현하였다.

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절연 바니시의 전기적특성 (Electrical Properties of Insulating Varnish)

  • 김정훈;신종열;변두균;이종필;조경순;김왕곤;홍진웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.299-302
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    • 2001
  • In this study, we are studied the electrical conduction and dielectric breakdown properties of insulating varnish. In order to analyze the molecular structure and physical properties of insulating varnishs, FT-lR was used. As the result, it can be confirmed that the peak of alcoholic group appeared in wavenumbers 3452[cm$\^$-1], the peak of =CH appeared in 3080[cm$\^$-1] and the peak of -CH appeared in 2919[cm$\^$-1] respectively. The following results were obtained from electrical properties of insulating varnish. The amplitude of current density was decreased by thickness increasing and the current density was effected by the thermal energy from external due to temperature increasing. In study temperature dependence of dielectric strength, the specimen of 10[$\mu\textrm{m}$] thickness was measurement from room temperature to 180[$^{\circ}C$]. It is confirmed that the temperature regions below 60[$^{\circ}C$] is due to electron avalanche breakdown and the temperature regions over 60[$^{\circ}C$] is due to free volume breakdown which makes electron movements easy.

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