• Title/Summary/Keyword: APD

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Development of Retina Photographing and Multi Channel Image Acquisition System for Thickness Measurement of Retina (망막 두께 측정을 위한 망막 촬영 및 다채널 영상획득장치 개발)

  • 양근호
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.1
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    • pp.13-17
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    • 2004
  • In order to measure the retina thickness, the retina photographing system and the multi-channel high speed image data acquisition system is developed. This system requires the optical processing techniques and the high speed image processing techniques. The HeNe laser beam is projected the retina in artificial eye and then we sensed the reflected laser signal using APD array. The laser projection system on retina using optical instruments is implemented. In order to project the plane laser beam on retina, laser photographing system used the polygon mirror for horizontal scanning and the galvano mirror for vertical scanning. We acquired retina images in each channel of APD array, transferred computer using PCI interface the image data after real-time A/D converting.

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지상전시 - APD seoul 2015 Best Creative Awards

  • (사)한국포장협회
    • The monthly packaging world
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    • s.266
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    • pp.120-124
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    • 2015
  • APD(ASIA Package Design)는 한국, 일본, 상해, 대만 4개국의 패키지디자인협회가 2년마다 개최하는 국제행사로 1993년도 한국에서 1회를 시작하여 2013년 상해행사까지 4개국 순회 개최로 주관하였다. 2015년은 한국에서 14회를 맞게 되어 전시, 컨퍼런스, 환영만찬과 공연의 내용으로 각국의 패키지디자인과 트렌드를 공유하며 발표하는 국제적 커뮤니티의 장이 되었다는 평가를 받고 있다. 지난 달 15일부터 18일까지 동대문디자인플라자(DDP) 갤러리문에서는 APD Seoul 2015 Best Creative Awards 수상작들이 전시되었다. 본 고에서는 나라별 수상작들을 살펴본다.

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6.25-Gb/s Optical Receiver Using A CMOS-Compatible Si Avalanche Photodetector

  • Kang, Hyo-Soon;Lee, Myung-Jae;Choi, Woo-Young
    • Journal of the Optical Society of Korea
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    • v.12 no.4
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    • pp.217-220
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    • 2008
  • An optical receiver using a CMOS-compatible avalanche photodetector (CMOS-APD) is demonstrated. The CMOS-APD is fabricated with $0.18{\mu}m$ standard CMOS technology and the optical receiver is implemented by using the CMOS-APD and a transimpedance amplifier on a board. The optical receiver can detect 6.25-Gb/s data with the help of the series inductive peaking effect.

A 2.4 GHz 802.11b Throughput Estimation In a Noisy Environment Using an Experimental Noise Parameter

  • Hur Min-Ho;Lim Sung-Jin;Kwon Sewoong;Yoon Young-Joong
    • Journal of electromagnetic engineering and science
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    • v.5 no.2
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    • pp.61-65
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    • 2005
  • In this paper, a numerical permissible disturbance model is proposed to preserve a throughput performance of a 2.4 GHz wireless LAN service. The model is composed of two parameters, a peak value and a time rate of noise signal. The model parameters are experimentally determined from an APD parameter measurement. The APD parameter is measured by using the APD measurement method which is recommended from CISPR/A/447/CD.

Single-Photon Generation and Low-Noise Detection based on APD for Quantum Key Distribution (양자키분배를 위한 단일광자 생성 및 APD 기반의 저잡음 검출)

  • Park, Jun-Bum;Abdessattar, Bouzid;Hwang, Sung-Hyen;Lim, Young-Geun;Moon, Sung-Uk
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1535_1536
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    • 2009
  • 본 논문에서는 1.5um 파장대에서 감쇄기를 이용한 유사단일광원을 이용하여 단일광자검출의 특성을 실험적으로 분석하였다. Gated Geiger 모드에서 APD를 동작 하여 열적 노이즈에 따른 양자효율을 측정하였다. 또한 APD를 이용하여 단일광자를 고속으로 검출시 문제가 되는 afterpulsing 노이즈의 온도별 특성을 분석하였다.

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High-Speed, High-Reliability Planar-Structure InP/InGaAs Avalanche Photodiodes for 10Gb/s Optical Receivers with Recess Etching (수광영역의 식각을 통한 단일확산 공정의 고속 평판형 InP/InGaAs 10Gb/s 광 검출기의 신뢰성)

  • Jung, Ji-Houn;Kwon, Yong-Hwan;Hyun, Kyung-Sook;Yun, Il-Gu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.1022-1025
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    • 2002
  • This paper presents the reliability of planar InP/InGaAs avalanche photodiodes (APD's) with recess etching, which is very crucial for the commercial 10-Gb/s optical receiver application. A versatile design for the planar InP/InGaAs APD's and bias-temperature tests to evaluate long-term reliability at temperature from 200 to $250^{\circ}C$. The reliability is examined by accelerated life tests by monitoring dark current and breakdown voltage. The lifetime of the APD's is estimated by a degradation activation energy. Based on the test results, it is concluded that the planar InP/InGaAs APD's with recess etching shows the sufficient reliability for practical 10-Gb/s optical receivers.

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I-V Characteristics of SAGCM APD by Varing Guard-Ring Depth (SAGCM APD 에서의 가드링 형태에 따른 I-V 특성 연구)

  • 현경숙;백영미
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.100-101
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    • 2003
  • 본 논문은 초고속 광통신용 검출기로 사용되고 있는 InP/InGaAs Avalanche Photodiode (APD)에 대한 연구로서 구조 변화에 따른 APD의 특성에 대해 연구하였다. 채택된 APB의 기본 구조는 Separated Absorption, Grading, Charge and Multiplication (SAGCM)구조로 u-InP 의 두께 3.5$\mu\textrm{m}$에~2.9$\mu\textrm{m}$ 만큼 Zn diffusion 하였으며, u-InGaAs 의 흡수층 두께는 0.8$\mu\textrm{m}$ 로 하였다. charge sheet 층의 도핑 농도는 ~ 3.5 $\times$ 10/sup 12//cm/sup 2/ 이고, 전극 구조는 back side illumination type이다. (중략)

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Growth Responses of two Tree Species Exposed to Simulated Acidic Rain and Ozone (산성비와 오존에 대한 두 수종의 생장반응)

  • Lee, Woong-Sang
    • The Korean Journal of Ecology
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    • v.17 no.2
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    • pp.131-141
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    • 1994
  • One-year-old yellow-poplar (Liriodendron tulipifera L.) and sweetgum (Liquidambar styraciflua L.) seedlings were exposed to 0.10 ${\mu}l/l\;O_3$and simulated acid rain at pH 3.0 for ten consecutive weeks. Shoot height growth (SHG), fresh weight (FWT), dry weight (DWT), apparent plastochron duration (APD) and foliar nutrient concentrations were measured. None of growth measurements, except the apparent plastochron duration (APD), were significantly affected by any treatment in yellow-poplar seedlings. APD was approximately 30% higher in seedlings exposed to $0.1{\mu}l/l\;O_3$ + pH 5.6 solution than any other treatment. Ozone significantly reduced SHG of sweetgum seedlings by 24% at the end of the ten-week fumigation. There were also significant effects of single and combined effects of ozone and simulated acid rain on APD in sweetgum. APD was significantly increased by 19.8% and 25.7% in seedlings exposed to $0.1{\mu}l/l\;O_3$ and pH 5.6 solution, respectively, and resulted in 46.1% higher APD in seedlings exposed to $0.1{\mu}l/l\;O_3$ + pH 5.6 solution compared with seedlings exposed to $0.0{\mu}l/l\;O_3$ + pH 3.0 solution. Phosphorus and sulphur were significantly greater in seedlings exposed to simulated rain at pH 3.0 compared with pH 5.6 for both species. Foliar S concentration was higher in seedlings exposed to $0.0{\mu}l/l\;O_3$ + pH 3.0 than in seedlings exposed to any other treatment in sweetgum. Ozone significantly increased Ca in sweetgum seedlings, however, ozone reduced Ca in yellow-poplar. Ozone also reduced S and Mg in sweetgum seedlings.

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Comparison of electrophysiological effects of calcium channel blockers on cardiac repolarization

  • Lee, Hyang-Ae;Hyun, Sung-Ae;Park, Sung-Gurl;Kim, Ki-Suk;Kim, Sung Joon
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.1
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    • pp.119-127
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    • 2016
  • Dihydropyridine (DHP) calcium channel blockers (CCBs) have been widely used to treat of several cardiovascular diseases. An excessive shortening of action potential duration (APD) due to the reduction of $Ca^{2+}$ channel current ($I_{Ca}$) might increase the risk of arrhythmia. In this study we investigated the electrophysiological effects of nicardipine (NIC), isradipine (ISR), and amlodipine (AML) on the cardiac APD in rabbit Purkinje fibers, voltage-gated $K^+$ channel currents ($I_{Kr}$, $I_{Ks}$) and voltage-gated $Na^+$ channel current ($I_{Na}$). The concentration-dependent inhibition of $Ca^{2+}$ channel currents ($I_{Ca}$) was examined in rat cardiomyocytes; these CCBs have similar potency on $I_{Ca}$ channel blocking with $IC_{50}$ (the half-maximum inhibiting concentration) values of 0.142, 0.229, and 0.227 nM on NIC, ISR, and AML, respectively. However, ISR shortened both $APD_{50}$ and $APD_{90}$ already at $1{\mu}M$ whereas NIC and AML shortened $APD_{50}$ but not $APD_{90}$ up to $30{\mu}M$. According to ion channel studies, NIC and AML concentration-dependently inhibited $I_{Kr}$ and $I_{Ks}$ while ISR had only partial inhibitory effects (<50% at $30{\mu}M$). Inhibition of $I_{Na}$ was similarly observed in the three CCBs. Since the $I_{Kr}$ and $I_{Ks}$ mainly contribute to cardiac repolarization, their inhibition by NIC and AML could compensate for the AP shortening effects due to the block of $I_{Ca}$.

Analysis of Quenching Resistor Effect to Improve Stability of TIA Circuit for APD (APD용 TIA 회로의 안정성 개선을 위한 Quenching 저항 영향 분석)

  • Ki, Dong-Han;Jin, Yu-Rin;Kim, Sung-Mi;Cho, Seong-Ik
    • Journal of IKEEE
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    • v.26 no.3
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    • pp.373-379
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    • 2022
  • In this paper, since the APD(Avalanche Photo Diode) for LTV(Light to Voltage) conversion uses a high voltage in the operating range unlike other PD(Photo Diode)s, the quenching resistor must be connected in series to prevent overcurrent when using the TIA(Transimpedance Amplifier). In such a case, quenching resistance may affect the transfer function of the TIA circuit, resulting in serious stability. Therefore, in this paper, by analyzing the effect of APD quenching resistance on the voltage and current loop transfer function of TIA, we propose a loop analysis and a method for determining the quenching resistance value to improve stability. TIA circuit with quenching resistance was designed by the proposed method and the stability of operation was verified through simulation and chip fabrication.