• Title/Summary/Keyword: Light Output

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100kHz PWM LED 광조사가 백서 골수세포에 미치는 영향 (The effect of 100KHz PWM LED light irradiation on RAT bone-marrow cells)

  • 천민우;김성환;김영표;이호식;박용필;유성미;이희갑;김태곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.512-513
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    • 2008
  • The study examined what effects 100kHz PWM LED light irradiation causes to bone marrow cells of SD-Rat when LED characterized cheap and safe is used onto the light therapy by replacing the low 1evel laser. We developed the equipment palpating cell proliferation using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on. Especially, to control the light irradiation frequency, FPGA was used, and to control the change of output value, TLC5941 was used. Consequent1y, the current value could be controlled by the change of 1eve1 in Continue Wave(CW) and Pulse Width Modulation(PWM), and the output of a high brightness LED could be controlled stage by stage. MTT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring 590nm transmittance of ELISA reader. As a result, the cell increase of Rat bone marrow cells was verified in 100kHz PWM LED light irradiation group as compared to non-irradiation group.

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Improvement of output coupling efficiency of organic light emitting device by using porous anodic alumina

  • Lee, Hyung-Sup;Choi, Ji-Young;Gao, Xinwei;Kim, Seong-Su;Lee, K.W.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.625-628
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    • 2004
  • Porous anodic alumina(PAA) which has arrays of nano size holes, was incorporated into organic light emitting devices. Porous anodic alumina on glass scattered the light generated from emitting layer and was decreased the waveguiding modes within the glass. An increase in the device coupling-out factor for the scattering structure is demonstrated.

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경량전철용 보조전원장치의 새로운 제어 기법 (New control strategy of Static Inverter for the Light Rail Transit)

  • 이은규;최재호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.190-193
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    • 2003
  • This paper Proposes 40 [KVA] rated SIV(Static Inverter) system for Light Rail Transit. The SIV Provide power of a fluorescent light in the car, Air-conditioner. and other equipments. To control output voltage it is used voltage control loop for constant voltage control and simultaneously used current control loop for instantaneous control at load changing. The Performance of SIV system will be verified by experimental results.

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색광 부호화와 전연산 후캐리 처리를 이용한 논리 및 산술연산 (Logic/Arithmetic Operation Using Color Light Encoding and Pre-operation Post-carry Processing Methods)

  • 황상현;배장근;김성용;김수중
    • 한국통신학회:학술대회논문집
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    • 한국통신학회 1991년도 추계종합학술발표회논문집
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    • pp.86-91
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    • 1991
  • A capability of performing the optical logic and arithmetic operations is followed by an effective encoding technique. In this paper, we proposed the color light encoding technique. By using this encoding technique, the space bandwidth product(SBP) is minimized in the output plane. In addition, we proposed the pre-operation pro-carry processing method that performs faster than the same time operation and carry processing method in optical computing. We proposed that the color liquid crystal device(CLCD) is used as the encoded color light input source.

경량전철용 보조전원장치의 개발 (Development of Static Inverter for the Light Rail Transit)

  • 이은규;염상구;최재호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(I)
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    • pp.522-527
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    • 2002
  • This paper proposes 40 [KVA] rated SW(Static Inverter) system for Light Rail Transit. The SIV provide power of a fluorescent light in the car, Air-conditioner, and other equipments. To control output voltage it is used voltage control loop for constant voltage control and simultaneously used current control loop for instantaneous control at load changing. The performance of SW system will be verified by experimental results.

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가시광통신에서 천이주파수 변조를 이용한 플리커 방지 (Flicker Prevention Through Transition-Frequency Modulation in Visible Light Communication)

  • 이성호
    • 센서학회지
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    • 제29권4호
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    • pp.243-248
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    • 2020
  • In this study, we applied transition-frequency modulation to prevent the flickering of light-emitting diodes (LEDs) in visible light communication (VLC). In the VLC transmitter, rectangular waveforms with transition frequencies of four and two in each bit time were used for the high and low bits, respectively, in the non-return-to-zero data. In the VLC receiver, an RC-high-pass filter (HPF) was used to eliminate the interference of the 120 Hz noise light from the adjacent lighting lamps, and an SR-latch circuit was used to recover the transmitted signal using spikes from the output of the RC-HPF. This configuration is useful for constructing VLC systems that are flicker-free and resistant to adjacent noise light interference.

A Calibration Study of Therapeutic Ultrasound Equipment Output Intensity Accuracy

  • Yuk, Goon-Chang;Ahn, Sang-Ho;Park, So-Hyun
    • The Journal of Korean Physical Therapy
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    • 제23권3호
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    • pp.37-42
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    • 2011
  • Purpose: The principal objective of this study was to evaluate the power output of ultrasound in Korean clinics and compare the value with Korean and global standards. Methods: A total of 69 units were measured for ultrasound power output. The normal range of power output level was ${\pm}30%$ of the output set according to KFDA standards. Device model, manufacturer, ERA, and BNR were obtained via simple questionnaires. A portable ultrasound power meter was used for output measurement. Results: 37 machines, with reported ERA values, were assessed for power output per unit area. Of these machines, 13 (37.14%) were considered to be compliant with US FDA standards at 0.5, 1.0, 1.5, $20W/cm^2$ and 18 (51.43%) were considered within KFDA standards. The remainder of the machines were outside the standard error and evidenced irregular output levels, even though most of them were the same model. Conclusion: Appropriate ultrasound intensity is incredibly important for safety and effective use. Therefore, the KFDA standards regarding ultrasound may require revision in light of global standards, including BNR and ERA additionally, attention should be paid to regular calibration for safe use in clinical practice.

Current Uniformity Enhancement for AMOLED Data Driver IC

  • Bae, Han-Jin;Bae, Joon-Ho;Choi, Byong-Deok;Kwon, Oh-Kyong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1436-1439
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    • 2005
  • A novel current-type data driver for active matrix organic light emitting diode (AMOLED) is proposed for current uniformity enhancement among its output channels. New architecture is composed of shadow DACs that precharge output stages, a single-real DAC that correct the output level to a real target current level and output stages that operate in 3 states of sampling, correcting and driving. Simulation results show that the proposed driving method and circuits improve the current uniformity among output channels of a current-type driver IC.

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콤팩트 형광램프용 다출력형 전자식 안정기의 설계 (Design of an Electronic Ballast of Multiple Power Output for Compact Fluorescent Lamps)

  • 곽재영;송상빈;여인선
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 A
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    • pp.413-415
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    • 1995
  • This paper presents a new approach in the design of multiple power output electronic ballasts for compact fluorescent lamps which power output range of 11W, 15W, 20W by using equivalent resistance and RLC equivalent circuit concept and frequency control. A multiple power output electronic ballast which adopts half-bridge inverter topology is set up to compare the results of PSpice simulation with experimental ones. Starting characteristics of lamp voltage, lamp current and light output are better than the existing electronic ballasts, and therefore is verified the validity of the proposed method.

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