• 제목/요약/키워드: Fast Switching

검색결과 560건 처리시간 0.035초

Depleted Optical Thyristor의 공핍전압에 관한 연구 (Optimization of GaAs/AIGaAs depleted optical thyristor structure for lower depletion voltage)

  • 최운경;김두근;최영완;이석;우덕하;변영태;김재헌;김선호
    • 한국광학회:학술대회논문집
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    • 한국광학회 2003년도 하계학술발표회
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    • pp.220-221
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    • 2003
  • We optimized the structure of a fully depleted optical thyristor (DOT) to achieve the faster switching speed and the lower power consumption by the depletion of charge at the lower negative voltage. The fabricated optical thyristor shows sufficient nonlinear s-shape I-V characteristics with the switching voltage of 2.85 V and the complete depletion voltage of -8.73 V. In this paper, using a finite difference method (FDM), we calculate the effects of parameters such as doping concentration and thickness of each layer to determine the optimized structure in the view of the fast and low-power-consuming operation.

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Cognitive Radio Based Jamming Resilient Multi-channel MAC Protocol for Wireless Network

  • Htike, Zaw;Hong, Choong Seon
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2009년도 추계학술발표대회
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    • pp.679-680
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    • 2009
  • Radio jamming attack is the most effective and easiest Denial-of-Service (DOS) attack in wireless network. In this paper, we proposed a multi-channel MAC protocol to mitigate the jamming attacks by using cognitive radio. The Cognitive Radio (CR) technology supports real-time spectrum sensing and fast channel switching. By using CR technologies, the legitimate nodes can perform periodic spectrum sensing to identify jamming free channels and when the jamming attack is detected, it can switch to un-jammed channel with minimum channel switching delay. In our proposed protocol, these two CR technologies are exploited for thwarting the jamming attacks.

Fast clip을 적용한 콘크리트궤도용 노스가동 분기기 개발 (Development of Movable nose crossing turnout on concrete track using Fast Clip)

  • 황광하;류기대;박춘복;박광련;윤병현
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.287-296
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    • 2011
  • Turnout is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction. A movable nose crossing frog is a device used at a railway turnout to eliminate the gap at the common crossing (High manganese, block, assembly crossing)which can cause impact damage, noise and vibration. Our government has a plan speed up of conventional line to 250km/h semi-high speed. We had already developed flexible turnout with fixed crossing(High manganese) and SFC fastening system can cover in the semi-high speed line In this study is about development of the movable nose crossing turnout available Semi-high speed line on concrete track. This paper describes about geometry, attack angle, bending stress at the nose, switching force, safety of continuous welded long rails. This movable nose crossing turnout is expected greatly increases passing speed of turnout in national railway.

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Two Approaches in LCDs With Fast Electro-optic Response: PSV-mode FLCDs and FM-TN-LCDs

  • Kobayashi, Shunsuke
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.911-914
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    • 2004
  • This paper discusses on new two LCD technologies featured by the fast electro-optic response:one is polymer-stabilized FLCDs that exhibit V-shaped electro-optic (EO) switching called PSV-mode FLCDs with response time of 400 ${\mu}$ s; and the other is TN-mode LCDs that exhibit a frequency modulation response (called PM-TN LCDs)and a peculiar sensitivity to the high frequency component of driving voltage waveforms resulting in a short decay time constant of 5ms and an enhancement in the over-driving that yields short response time of 1ms between two gray levels.

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Novel Driving Method for fast Response Time in Vertical Alignment LCDs

  • Song, Jang-Kun;Jun, Man-Bok;Park, Bo-Yoon;Seomun, San-Seong;Lee, Kye-Hun;Choi, Kwang-Soo;Kim, Sang-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.205-208
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    • 2004
  • The switching mechanism of multi-domain vertical alignment mode LCD and delayed on response time phenomenon in special conditions are investigated. A modified DCC (Dynamic Capacitance Compensation), DCCII has been developed for the fast response time performance in PVA TFT-LCD TVs. DCCII applies a pre-tilt voltage to addressed pixels during the previous frame in addition to an overshoot voltage. In result, the response time less than 8 msec, has been obtained for all moving images through the DCCII technique.

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MB-OFDM UWB 시스템을 위한 주파수 합성기의 유형별 설계 및 비교 (Design and Comparison of the Frequency Synthesizers for MB-OFDM UWB Systems)

  • 이재경;정태현;박종태;유종근
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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    • pp.482-484
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    • 2006
  • This paper describes fast-hopping frequency synthesizers for multi-band OFDM(MB-OFDM) ultra-wide band(UWB) systems. Three different structures in generating 3 center frequencies(3432MHz, 3960MHz, 4488MHz) are designed and compared. The first structure generates 3 center frequencies using only one PLL operating at 4224MHz. The second uses three PLLs operating at corresponding center frequencies. The third employes two PLLs operating at 3960MHz and 528MHz. Simulation results using a 0.18um RF CMOS process parameters show that the third structure exhibit the best characteristics. The band switching time of the proposed synthesizer is less than 1.3ns and the spur is less than -36dBc. The synthesizer consumes 22mA from a 1.8V supply.

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AUTOSAR CAN Interface 확장을 이용한 ECU의 소프트웨어 업데이트 방법 (Fast ECU Software Update Algorithm using by Extending AUTOSAR CAN Interface)

  • 김종욱;백장운;권기구;이석규
    • 대한임베디드공학회논문지
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    • 제8권3호
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    • pp.163-169
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    • 2013
  • This paper proposes a novel ECU (Electronic Control Units) update algorithm for AUTOSAR based automotive embedded system. The proposed algorithm provides fast and easy ECU update by extending AUTOSAR CAN Interface. The proposed system removes the update sequences from PDUR to RTE (ECU update program), and it stops other ISRs and operating system in order to reduce unnecessary context switching time. In experimental results, we can see that the proposed algorithm reduces update time.

A Study on the Color Performance of FFS Mode Using the Various Analysis Methods

  • Park, Se-Hong;Park, Eun-Jung;Han, Sang-Hun;Park, Jong-Gyun;Park, In-Cheol;Lee, Kyung-Ha;Lee, Jung-Yeal
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.691-694
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    • 2006
  • So far, we have done much research improving quality of LCD TV. Recently, we have developed 26" WXGA LCD TV by advance fringe field switching (AFFS) technology with smooth and every scene realistic in color image that obtained from the amazing authentic color delivery, optical characteristic and fast response time. Our upgrade device has shown the brightness over 600nits (Color shift <0.015 and Transmittance ratio > 5.5%), gray to gray response time under 6ms, contrast ratio over 1200:1 and viewing angle over 178/178, respectively. And also, motion artifacts improved by fast response of LC with low viscosity, cell gap and dielectric constant.

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UWB 펄스전자파 발생용 원통형 Marx 펄스발생장치개발 (Coaxial Marx Type Pulse Generator for UWB EM Pulse)

  • 장용무;이상욱
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.121-121
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    • 2010
  • As the industrial technology is getting higher, the pulsed power technology is required from various fields such as thermonuclear fusion energy sources, military applications, electric power distribution, and a variety of new specialized needs. This technology deals with the generation of very high power electromagnetic pulses through fast switching. We fabricated a pulsed power generator, named EMD pulse generator, by using Marx circuit with 200 kV high, 50 ns fast rise time. In this paper, we described about an effect of stray capacitance of coaxial Marx generator, EPG-AM200k, and a comparing the results of experiments and circuit analysis.

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Design of IM Control System for Industrial Sewing Ma-chines

  • Hwang, Dae-kyu;Oh, Tae-Seok;Kim, Il-Hwan
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.91.3-91
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    • 2002
  • This paper describes a design of an induction motor control system for industrial sewing machines. On the basis of vector control principle, the control system is simulated by using the ACSL, implemented on a DSP(TMS320C31).A space vector modulation is used as the inverter switching strategy. For the application of industrial sewing machines, A fast acceleration (deceleration) and removal of velocity ripples are required, because a sewing quality and sewing machines life time depends on these characteristics. The designed control system has fast dynamic characteristics and small speed vibration. The result is applied to the industrial sewing machine and result are shown.

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