• 제목/요약/키워드: Semiconductor laser

검색결과 525건 처리시간 0.024초

저강도레이저 조사가 근육압좌손상 후 척수분절의 EGF 발현에 미치는 영향 (Effects of Low Power Laser for the Expression of EGF after Muscle Crush Injury)

  • 김석범;김동현;남기원;이선민;김진상
    • The Journal of Korean Physical Therapy
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    • 제14권2호
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    • pp.16-25
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    • 2002
  • Low energy laser irradiation(LELI) therapy in physical therapy is widespread but the mechanisms are not fully understood. The purpose of the present study was to examine the epidermal growth factor(EGF)'s expression within lumbar spinal cord which corresponding with crushed extensor digitorum longus(EDL) of rats after low-power laser irradiation applied. After a crushed injury on the right EDL, low-power laser irradiation was applied by using 2000mW, 2000Hz, 830nm GaAlAs(Gallium-aluminum-arsenide) semiconductor diode laser. The laser treatment was performed with 10 minutes daily for 3days. After EDL crush injury, EGF immunoreactive positive neurons in experimental group were progressively decreased from the first to third days. Especially 1 day subgroup is highly expressed in dorsal horn(Lamina I, II, III) and around of central cannal of spinal cord(Lamina VII). Control group was only expressed slightly at 3 days. This study suggests that LELI stimulate that release and migration of EGF in spinal cord, which distict to wound site, therfore promote wound healing of EDL crush injury.

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Sensing Properties of Ga-doped ZnO Nanowire Gas Sensor

  • Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • 제16권2호
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    • pp.78-81
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    • 2015
  • Pure ZnO and ZnO nanowires doped with 3 wt.% Ga (‘3GZO’) were grown by pulsed laser deposition in a furnace system. The doping of Ga in ZnO nanowires was analyzed by observing the optical and chemical properties of the doped nanowires. The diameter and length of nanowires were under 200 nm and several ${\mu}m$, respectively. Changes of significant resistance were observed and the sensitivities of ZnO and 3GZO nanowires were compared. The sensitivities of ZnO and 3GZO nanowire sensors measured at 300℃ for 1 ppm of ethanol gas were 97% and 48%, respectively.

Noise Suppression of Spectrum-Sliced WDM-PON Light Sources Using FP-LD

  • Lee, Woo-Ram;Cho, Seung-Hyun;Park, Jae-Dong;Kim, Bong-Kyu;Kim, Byoung-Whi
    • ETRI Journal
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    • 제27권3호
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    • pp.334-336
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    • 2005
  • We improved the performance of the spectrum-sliced light source for wavelength-division-multiplexed passive optical networks by employing a Fabry-Perot laser diode(FP-LD). We found that the FP-LDs can suppress the intensity noise as significantly as using a gain-saturated semiconductor optical amplifier. The transmission characteristics were measured and analyzed in both conditions with and without employing an FP-LD.

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FUZZY POSITION/FORCE CONTROL OF MINIATURE GRIPPER DRVEN BY PIEZOELECTRIC BIMORPH ACTUATOR

  • Kim, Young-Chul;Chonan, Seiji;Jiang, Zhongwei
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.24.2-27
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    • 1996
  • This paper is a study on the fuzzy force control of a miniature gripper driven by piezoelectric bimorph actuator. The system is composed of two flexible cantilevers, a stepping motor, a laser displacement transducer and two semiconductor force sensors attached to the beams. Obtained results show that the present artificial finger system works well as a miniature gripper, which produces approximately 0.06N force in the maximum. Further, the fuzzy position/force control algorithm is applied to the soft-handing gripper for stable grasping of a object. It revealed that the fuzzy rule-based controller be efficient controller for the stable drive of the flexible miniature gripper. It also showed that two semiconductor strain gauges located in the flexible beam play an important roles for force control, position control and vibration suppression control.

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A Technique for Analyzing LSI Failures Using Wafer-level Emission Analysis System

  • Higuchi, Yasuhisa;Kawaguchi, Yasumasa;Sakazume, Tatsumi
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제1권1호
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    • pp.15-19
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    • 2001
  • Current leakage is the major failure mode of semiconductor device characteristic failures. Conventionally, failures such as short circuit breaks and gate breakdowns have been analyzed and the detected causes have been reflected in the fabrication process. By using a wafer-level emission-leakage failure analysis method (in-line QC), we analyzed leakage mode failure, which is the major failure detected during the probe inspection process for LSIs, typically DRAMs and CMOS logic LSIs. We have thus developed a new technique that copes with the critical structural failures and random failures that directly affect probe yields.

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VELOCITY AND ITS DIRECTION MEASUREMENT OF SCATTERER WITH DIFFERENT VELOCITIES USING SELF-MOXING SEMICONDUCTOR LDV

  • Shinohara, Shigenobu;Haneda, Yoshiyuki;Suzuki, Takashi;Ikeda, Hiroaki;Yoshida, Hirofumi;Sawaki, Toshiko;Mito, Keiichiro;Sumi, Masao
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.1966-1970
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    • 1991
  • The self-mixing type semiconductor laser Doppler velocimeter(SM-LDV) is applied to measure two simultaneously moving targets with different velocities in the same direction as a prototype target for multiscatterers. The measured beat waveform is found to be a composite wave of each beat waveform measured fran each of only moving target. In the composite waveform, each one-cycle wave has a feature of the sawtooth wave. This fact shows a possibility to discriminate the flow direction of fluid containing multiscatterers with distributed velocities by cooperating an improved version of the direction discrimination circuit already devised by the authors.

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광-마이크로파 기반 유도플라즈마의 과도응답 특성에 관한 연구 (Study of Transient Response in Non-uniform Plasma Layer with Optically-Controlled Microwave Pulses)

  • 왕설;최유순;박종구;김용갑
    • 전기학회논문지
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    • 제58권6호
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    • pp.1174-1179
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    • 2009
  • In this paper we develop the characteristic of density on non-uniform plasma in different layer of the semiconductor with optically controlled microwave pulses. The transient response of the microwave pulses in different plasma layer has been evaluated by calculating the variation of the reflection function of dielectric microstrip lines. The lines has used under open-ended termination containing optically induced plasma region, which has illuminated a laser source. The characteristics impedances resulting from the presence of plasma are evaluated by the transmission line model. The analyzes the variation of transient response in a 0.01cm layer near the surface for frequency range from 1GHz to 128GHz. The diffusion length LD is larger than compared to the absorption depth $l/_{\alpha}l$. The variation of characteristic response in plasma layer with microwave pulses which has in deferentially localized has been evaluated analytically.

열처리 온도에 따른 P-doped ZnO 박막의 구조적 및 전기적 특성 (Structure and Electrical Properties of P-doped ZnO Thin Films with Annealing Temperatures)

  • 한정우;윤영섭;강성준;정양희
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.501-502
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    • 2008
  • In this study, P-doped ZnO thin films were prepared on sapphire substrates by pulsed laser deposition and annealing method. The electrical properties were investigated as a function of annealing temperatures at a fixed oxygen pressure. The XRD measurement showed that p-doped ZnO thin films were c-axis oriented. The Hall measurement showed that p-type ZnO thin film was observed. The carrier concentration of $1.18{\times}10^{16}cm^{-3}$ and the mobility of $0.96\;cm^{-3}/Vs$ were obtained for the P-doped ZnO thin film fabricated annealing temperature $850^{\circ}C$.

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반도체 레이저의 주파수변조 특성에 대한 등가회로 모델 (Circuit Model for Frequency Modulation Characteristics for Semiconductor Lasers)

  • 소준호;송우영;김성환;홍완희
    • 대한전자공학회논문지
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    • 제26권6호
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    • pp.102-107
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    • 1989
  • 본 논문은 반도체 레이저의 주파수변조 응답특성에 대한 새로운 회로모델링 방법을 제시하였다. 특히 본 등기회로 모델은 캐리어농도의 변조효과 뿐만 아니라 온도효과에 따른 변조특성을 고려하였다. 본 모델에서 예상된 이론치는 기존에 발표된 CSP형 레이저의 정형파변조 실험결과와 잘 일치하고 있음을 알 수 있었다.

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BGA(Ball Grid Array) 높이 데이타의 고속 측정 (High Speed Measurement of Ball Height Data for Ball Grid Arrays)

  • 조태훈;주효남
    • 반도체디스플레이기술학회지
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    • 제5권1호
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    • pp.1-4
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    • 2006
  • Recently, Ball Grid Arrays(BGAs) are getting used more frequently for a package type. The connectors on a BGA consist of a large number of small solder balls in a grid shape on its bottom side. However, since balls of BGAs mounted on PCBs are not visible, inspection before mounting them is indispensable. High speed non-contact 3D measurement technologies are necessary far real-time measurement of ball height, the most important inspection item. In this paper, an accurate 3D data acquisition system for BGAs is proposed that can acquire 3D profile at high speed using a 3D smart camera and laser slit ray projection. Some clipping and morphological filtering operations are employed to remove spiky error data, which occur due to reflections from some ball area to camera direction.

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