• 전기학회논문지
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• 제57권4호
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• pp.629-634
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• 2008

In this paper, we propose a simple numerical formula which can estimate the additional delay time due to interconnection branches in general source-termination scheme. We show that interconnection branches have influence on both signal quality and time delay. Using the proposed numerical formula, time delay can be easily predicted by system designers.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.490-492
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• 2010

Center-tapped termination을 가진 stub series-termination logic (SSTL) 채널을 지원하기 위한 전압모드 송신단을 제안한다. 제안하는 송신단은 진단 모드를 지원하고 신호보전성을 향상시키기 위해 출력레벨 조절수단을 가지며, 가변 병렬 터미네이션을 사용하여 swing level을 조절하는 동안 송신단의 출력 저항을 일정하게 유지시켜준다. 또한 제안하는 송신단의 off-chip 저항은 기생 캐패시터, 인덕터에 의한 termination의 임피던스 부정합을 줄여준다. 제안된 송신단을 검증하기 위해서 $50{\Omega}$의 출력저항을 유지하면서 8-레벨의 출력을 제공하는 전압모드 송신단을 1.5V의 70nm 1-poly 3-metal DRAM공정을 이용하여 구현하였다. 수신단 termination이 존재하지 않는 SSTL 채널에서 제안하는출력레벨 조절이 가능한 송신단을 이용함으로 1.6-Gb/s에서 54%의 jitter 감소가 측정되었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.800-801
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• 2005

• Journal of the Optical Society of Korea
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• 제13권3호
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• pp.361-366
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• 2009

We propose the performance enhancing method optimization of an asynchronous 2.5 Gbps/1.25 Gbps optical subscriber network with inverse RZ (Return to Zero) coded downstream and NRZ (Non Return to Zero) upstream re-modulation by adjusting threshold level control of a receiver. We theoretically analyze the BER (Bit Error Rate) performance by modeling the occurrence of BER by simulation with MATLAB according to the types of downstream data. The results have shown that the normalized threshold level in an optical receiver could be saturated at 1/3 as the SNR (Signal to Noise Ratio) increases. The needed SNR for obtaining the BER $10^{-9}$ can be reduced by $\sim$5 dB by optimizing the normalized threshold level at 1/3 instead of by using the conventional receiver with threshold level of 0.5. The proposed system can be a useful technology for asynchronous optical access networks with asymmetric upstream and downstream data rates, because the improved minimum receiving power could replace a light source with a source with lower power and lower cost in an OLT (Optical Line Termination).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.493-498
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• 2004

The EMI noise source in a switching mode power supply is dominated by a common mode noise. If we can understand the common mode noise occurring mechanism, it is resulted to find out the method to suppress the EMI noise source in the switching mode power supply. The common mode noise is occurring mostly due to circuit is unbalanced which is caused by the capacitive coupling to frame ground, which passes through a heatsink of the switching devices. This research paper presents a new effective balancing method of buck converter circuit by mean of grounding the parasitic and compensation capacitors in correct proportion which is called that the common mode impedance balance (CMIB). The CMIB can be achieved by source, transmission line and termination balanced, such balancing, the common mode current will be cancelled out in the frame ground. The greatly reduced common mode noise can be confirmed by the experimental results.

• 전기학회논문지
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• 제57권3호
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• pp.416-420
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• 2008

This paper proposes a new method to improve signal characteristics at branches frequently met in system-level routing. We also introduce the numerical formula which can estimate the time delay due to branches and the simple design guideline for system-level routing. Finally, we propose the routing method which can eliminate the signal reflection for the case of one driver and two receivers (multi-drop topology).

• 대한전자공학회논문지TC
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• 제38권2호
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• pp.6-12
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• 2001

CBR 소스 트래픽에 대한 ATM 교환기와 광대역 망종단장치의 셀전달지연을 측정하여 국내영역에서의 셀전달지연을 추정하였다. 추정결과 I.356의 할당원칙에 의한 국내영역의 셀전달지연 목표치를 만족하였다. Chernoff 누적방법에 기초한 peak to peak CDV 할당방법을 제안하고 국내영역의 노트들에 적용하였다. 수치해석 결과 전송경로상에 놓인 노드수와 각 노드에서의 CDV가 증가하는 경우에 제안된 할당방법이기존의 균등할당 방법에 비해 정확도가 개선되었다.

• 한국항공우주학회지
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• 제34권4호
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• pp.102-109
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• 2006

본 논문에서는 검증위성(KoDSat)의 시스템 레벨 전자기파(EMC) 환경시험 및 전자기파(EMC) 규격을 초과한 시험결과에 대해서 발사체에 대한 영향성 분석 및 하드웨어 개선 방법에 대하여 논하고, EMC2000 소프트웨어 해석을 통해 KSLV-1 발사체의 비행종단시스템(FTS : Flight Termination System)에 영향을 줄 수 있는 검증위성의 전자기파 노이즈원을 도출하였다. 또한 도출된 전자기파(EMC) 노이즈원은 EMI 필터, 접지, 쉴딩(Shielding) 처리 기법을 데이터획득장치(DAU) 전력보드(Power Board)에 적용하여 미약한 값으로 제거되었다. 그리고 이와 같은 일련의 분석과정에 의해 새로 설계된 전력보드는 검증차원에서 데이터획득장치(DAU)에 장착되어 박스자체 전자기파(EMC) 시험 및 최종 2차 검증위성 시스템 레벨 전자기파 시험을 통해 확인되었고, 측정 결과는 저주파대역과 UHF 주파수대역(430Mhz)에서 만족할 만한 감쇄레벨 값을 나타내었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.367-371
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• 2014

Based on ISO 7235, an experimental setup to measure the acoustic performance of splitter type dissipative silencers are fabricated. The length of each duct, sound source, microphone locations, modal filter, and anechoic termination are considered in the design of this setup. The modal filter is a particularly important factor because it affects the limit of measurement, which is also determined by the amount of flanking transmission of sound generated by the sound source to microphones. The effects of absorptive materials, media which covers the materials, and the number of splitters on the noise reduction of the sample silencers are experimentally investigated. The insertions loss of silencers with media and higher number of splitters increases, especially at higher frequencies.

• 한국전기전자재료학회논문지
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• 제22권6호
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• pp.462-465
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• 2009

Schottky barrier thin film transistors (SB-TFT) on polycrystalline silicon(poly-Si) are fabricated by platinum silicided source/drain for p-type SB-TFT. High quality poly-Si film were obtained by crystallizing the amorphous Si film with excimer laser annealing (ELA) or solid phase crystallization (SPC) method, The fabricated poly-Si SB-TFTs showed low leakage current level and a large on/off current ratio larger than 10), Significant improvement of electrical characteristics were obtained by the additional forming gas annealing in 2% $H_2/N_2$ ambient, which is attributed to the termination of dangling bond at the poly-Si grain boundaries as well as the reduction of interface trap states at gate oxide/poly-Si channel.