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Fabrication of transducer optimized acousto optic modulator for laser projection display (Transducer 최적화 설계에 의한 Laser Projection Display용 음향광학변조기 제작 및 특성평가에 대한 연구)

  • 차승남;이항우;김용훈;황영모
    • Korean Journal of Optics and Photonics
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    • v.8 no.5
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    • pp.410-414
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    • 1997
  • Laser projection display is a full color display system for large area. In this system, laser beams are modulated at acousto optic modulators(AOM) according to the video signal. AOM consists of a $TeO_2$ crystal and a $LiNbO_3$ transducer. We calculated the acoustic wave propagating from transducer to acousto optic media and made AOM by the calculated results. We compared calculated results with fabricated AOM by measuring modulation efficiency at various frequency. The modulation efficiency of AOM is 85% at the carrier frequency of 144MHz and the rise time is 41.5 ns.

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Immobilization of Lum,brokinase on the Surface of Polyurethane by using the Photoreactive Poly(acrylic acid) (광반응성 poly(acrylic acid)를 이용한 Lumbrokinase 의 polyurethane 표면 고정화 방법에 관한 연구)

  • 김현정;류은숙;김종원;민병구
    • Journal of Biomedical Engineering Research
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    • v.20 no.6
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    • pp.547-553
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    • 1999
  • 생체재료로 사용되는 polyurethane(PU) 표면에 항혈전성 lumbrokinase(LK)를 고정함으로써 생체적합성을 향상시키고자하였다. 먼저 LK를 PU 표면에 고정하기 위한 가교제로서 4-azidoaniline hydrochloride와 poly(acrylic acid)를 이용하여 4-azidophenyl 작용기가 amido 결합으로 치환된 수용성, 광반응성 poly(acrylic acid)(PPa-II)를 합성하였다. H-nuclear magnetic reasonance spectrum(500MHz H-NMR)의 6-7 peak와 infrared spectrum (FT-IR) 의 2125.48 cm peak으로부터 PPA-II의 합성을 지원하였다. EH한 4-azidophenyl 작용기가 poly(acrylid acid) 잔기에 치환된 정도는 UV/VIS adpectrophotometric spectrum을 확인한 결과 11~14%임을 알 수있었다. 0.5 1및 5% PPA-II를 각각 광반응하여 얻은 PU는 39.5, 161.8 및 181.5 nmole/$\textrm{cm}^2$의 농도로 표면에 carvoxyl 작용기가 유도되었음을 알 수있었다. 0.05M KH2PO4 (pH 4.5) 용액에서 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide(EDC)를 촉매로 사용하여 LK를 PU표면에 amido 공유결합으로 고정하였으며, 이것은 지속적인 fibrinolytic 활성도를 보였다. PPA-II를 이용한 표면 개질 방법은 수용성 반응조건에서 이루어진다는 점과 광반응을 이용함으로써 특정부위에서의 표면개질이 가능하다는 점에서 그 응용가치가 크며 아울러 PU의 생체적합성을 향상시킬 수 있는 방법으로서 판단된다.

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Microwave fixation of Setaria Digitata for scanning electron microscopy (선충류의 주사전자현미경적 관찰을 위한 마이크로웨이브 고정법)

  • Lee, San-Soo;Cho, Kyoung-Oh;Shin, Kil-Sang;Shin, Sung-Shik
    • Korean Journal of Veterinary Research
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    • v.47 no.2
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    • pp.203-207
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    • 2007
  • Conventional processing of biological materials including nematode parasites for scanning electron microscopy includes fixation with glutaraldehyde and osmium, followed by dehydration in an ascending grade of ethanol, and finally freeze drying. This procedure takes about 8 to 12 h depending on the characteristics of samples. Microwave irradiation of 2,450 MHz enhance the action of cross-linking fixatives and can greatly accelerate various stages of tissue processing. In this study, samples of nematode parasites, Setaria digitata, were fixed by a combination of conventional chemical fixation and the microwave irradiation during the process. The microwave irradiation was also incorporated in the serial dehydration process with ethanol. The complete procedure from the initial fixation to the completion of dehydration with ethanol was reduced to 1 h with good preservation of the ultrastructural details of the specimens.

A Thin Folded Dipole UHF RFID Tag Antenna with Shorting Pins for Metallic Objects

  • Tang, Tao;Du, Guo-Hong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.9
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    • pp.2253-2265
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    • 2012
  • A novel folded dipole type microstrip patch antenna designed for ultrahigh frequency (UHF) band radio frequency identification (RFID) tag is presented in this paper, which can be used on the metallic objects. The presented antenna is fabricated on a very thin Rogers 5880 substrate with a thickness of 0.508 mm. The structure consists of two folded dipole and two symmetrical shorting pins placed at both sides of feed point. An adjustable frequency response can be easy obtained via modify the location and radius of the shorting pins. The antenna has been analyzed by full wave simulations soft. The simulated bandwidth is about 67.2 MHz, which covers the Europe and North America UHF RFID frequency range. A manufactured prototype has been fabricated and measured to demonstrate the antenna performances. The simulation results agree with the measurement data well. The measured maximum reading range of the prototype can be reached 4.1 m in free space, and 3.2 m on a metal plate whose size is $150{\times}150{\times}8mm^3$.

Development of Time Measure System for Acceleration of Gravity Experiment (중력 가속도 실험을 위한 시간 측정 시스템 개발)

  • Lee, Hyeon-Hee;Kim, Seong-Gon;Chin, Dal-Bok
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2280-2284
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    • 2002
  • This study is to develop a time measure system for acceleration of gravity verification. The system can measure time interval between two points when an object passes through the points. The system has 1${\mu}$sec time resolution. The AT90S8515 microprocessor, product of ATMEL. can make 1${\mu}$sec time resolution possible connected with the 8 MHz fine crystal oscillator. The two external signals called 'start' and 'stop' have AT90S8515 that counted time intervals of the two signals. Sensors are composed of the IR beam emitting diode. TNL108 and the IR beam receiving photo diode, TNL601, produced by NEC company. In order to acquire the measurement of exactitude of the system, measure the pendulum period. Experimental result, the average period =3.0406sec with pendulum length of 2.314m. The acceleration of gravity g=$908821{\pm}6.416{\times}1^{-4}m/s^2$.

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A 256-Radix Crossbar Switch Using Mux-Matrix-Mux Folded-Clos Topology

  • Lee, Sung-Joon;Kim, Jaeha
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.6
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    • pp.760-767
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    • 2014
  • This paper describes a high-radix crossbar switch design with low latency and power dissipation for Network-on-Chip (NoC) applications. The reduction in latency and power is achieved by employing a folded-clos topology, implementing the switch organized as three stages of low-radix switches connected in cascade. In addition, to facilitate the uniform placement of wires among the sub-switch stages, this paper proposes a Mux-Matrix-Mux structure, which implements the first and third switch stages as multiplexer-based crossbars and the second stage as a matrix-type crossbar. The proposed 256-radix, 8-bit crossbar switch designed in a 65nm CMOS has the simulated power dissipation of 1.92-W and worst-case propagation delay of 0.991-ns while operating at 1.2-V supply and 500-MHz frequency. Compared with the state-of-the-art designs in literature, the proposed crossbar switch achieves the best energy-delay-area efficiency of $0.73-fJ/cycle{\cdot}ns{\cdot}{\lambda}^2$.

Composite $BaTiO_3$ Embedded capacitors in Multilayer Printed Circuit Board (다층 PCB에서의 $BaTiO_3$ 세라믹 Embedded capacitors)

  • You, Hee-Wook;Park, Yong-Jun;Koh, Jung-Hyuk
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.2
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    • pp.110-113
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    • 2008
  • Embedded capacitor technology is one of the effective packing technologies for further miniaturization and higher performance of electric packaging system. In this paper, the embedded capacitors were simulated and fabricated in 8-layered printed circuit board employing standard PCB processes. The composites of barium titanante($BaTiO_3$) powder and epoxy resin were employed for the dielectric materials in embedded capacitors. Theoretical considerations regarding the embedded capacitors have been paid to understand the frequency dependent impedance behavior. Frequency dependent impedance of simulated and fabricated embedded capacitors was investigated. Fabricated embedded capacitors have lower self resonance frequency values than that of the simulated embedded capacitors due to the increased parasitic inductance values. Frequency dependent capacitances of fabricated embedded capacitors were well matched with those of simulated embedded capacitors from the 100MHz to 10GHz range. Quality factor of 20 was observed and simulated at 2GHz range in the 10 pF embedded capacitors. Temperature dependent capacitance of fabricated embedded capacitors was presented.

A Study on the Fatigue and Data Retention Characteristics of Single Grained PZT Thin Films (단결정립 PZT 박막의 피로 및 정보 유지 특성에 관한 연구)

  • Lee, Jang-Sik;Ju, Seung-Gi
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.5
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    • pp.1-8
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    • 2000
  • Fatigue and data retention characteristics of the Pt/PZT/Pt structure using single grain PZT thin films by PZT seeding method were investigated. In case of fatigue, there is no loss in switched polarization up to 2$\times$10$^{11}$ cycles using 1MHz square wave form at $\pm$10V and no data loss after 30000sec of memory retention at room temperature. From the activation energy measured at high temperatures, the time required 20% loss in remanent polarization is estimated to be 6.6$\times$10$^{7}$ years at room temperature.

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Class E Power Amplifiers using High-Q Inductors for Loosely Coupled Wireless Power Transfer System

  • Yang, Jong-Ryul;Kim, Jinwook;Park, Young-Jin
    • Journal of Electrical Engineering and Technology
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    • v.9 no.2
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    • pp.569-575
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    • 2014
  • A highly efficient class E power amplifier is demonstrated for application to wireless power transfer system. The amplifier is designed with an L-type matching at the output for harmonic rejection and output matching. The power loss and the effect of each component in the amplifier with the matching circuit are analyzed with the current ratio transmitted to the output load. Inductors with a quality factor of more than 120 are used in a dc feed and the matching circuit to improve transmission efficiency. The single-ended amplifier with 20 V supply voltage shows 7.7 W output power and 90.8% power added efficiency at 6.78 MHz. The wireless power transfer (WPT) system with the amplifier shows 5.4 W transmitted power and 82.3% overall efficiency. The analysis and measurements show that high-Q inductors are required for the amplifier design to realize highly efficient WPT system.

A 8b 1GS/s Fractional Folding-Interpolation ADC with a Novel Digital Encoding Technique (새로운 디지털 인코딩 기법을 적용한 8비트 1GS/s 프랙셔널 폴딩-인터폴레이션 ADC)

  • Choi, Donggwi;Kim, Daeyun;Song, Minkyu
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.1
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    • pp.137-147
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    • 2013
  • In this paper, an 1.2V 8b 1GS/s A/D Converter(ADC) based on a folding architecture with a resistive interpolation technique is described. In order to overcome the asymmetrical boundary-condition error of conventional folding ADCs, a novel scheme with an odd number of folding blocks and a fractional folding rate are proposed. Further, a new digital encoding technique with an arithmetic adder is described to implement the proposed fractional folding technique. The proposed ADC employs an iterating offset self-calibration technique and a digital error correction circuit to minimize device mismatch and external noise The chip has been fabricated with a 1.2V 0.13um 1-poly 6-metal CMOS technology. The effective chip area is $2.1mm^2$ (ADC core : $1.4mm^2$, calibration engine : $0.7mm^2$) and the power dissipation is about 350mW including calibration engine at 1.2V power supply. The measured result of SNDR is 46.22dB, when Fin = 10MHz at Fs = 1GHz. Both the INL and DNL are within 1LSB with the self-calibration circuit.