• Title/Summary/Keyword: LED detector

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The Study of Fire Detector Circuit with Wireless Communication (무선통신기능을 갖는 화재감지기 회로에 대한 연구)

  • Baek, Dong-Hyun;Kim, Jang-Won
    • Fire Science and Engineering
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    • v.24 no.1
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    • pp.111-115
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    • 2010
  • For the development of fire detector equipments that was fused independent type of fire detector and a wireless communication function, this paper adopted a signal processing method of an independent formation fire sensor by a ZigBee communication method, and it was designed that the combinations of fire detector and wireless communications network were enabled. When a fire occurred, output voltage of a fire detector was 0.4 V, the movement pulse width was $600{\mu}s$, and that was confirmed by an experiment. When it has lookout state, LED worked by 30 s cycle and working current is 0.12 mA. When a fire occurred, LED worked by 0.5 s cycle and working current was 7 mA, and through this experiment of power source, Chamber tester, smoke tester,IRED, LED lighting, the propriety of the method that we showed in this paper confirmed.

A Passive Visible Light Transponder Using an LED for an Optical Transceiver (LED를 광송수신 소자로 사용한 수동형 가시광 트랜스폰더)

  • Lee, Seong-Ho
    • Journal of Sensor Science and Technology
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    • v.24 no.4
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    • pp.232-238
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    • 2015
  • In this paper, we introduce a passive transponder in which an LED is used for both a light transmitter and a receiver, and a solar cell is used for supplying power to the all devices in the transponder. The LED in the transponder operates as a photodetector in the receiving mode, and acts as a light source in the transmitting mode. The current responsivity of the LED detector was measured to be in the order of $10^{-4}A/W$, and the receiving bandwidth with a load resistance of $10k{\Omega}$ was about 10 to 30 kHz. Using the LED for an optical transceiver in a VLID transponder, the detection range was about 70 cm when the transponder was illuminated by the visible light from a $3{\times}3$ LED array in a reader.

A Study of the Rate of Rise Spot Type Heat Detector on the Artificially Accelerated Aging Characteristics (차동식 스포트형 열감지기의 인공 가속열화특성에 관한 연구)

  • Kim, Chan-Young
    • Fire Science and Engineering
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    • v.25 no.2
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    • pp.107-113
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    • 2011
  • This paper presents the results of artificially accelerated aging characteristics of the rate of rise spot type heat detectors. This experiment carried out to investigate the detector's operating characteristics when a fire was broken out or the regular tests were performed. The result showed that the delay of operating time or no-operation of heat detector which was made by company B and used in the field for 5 years may be occurred even at the $100^{\circ}C$. This result is due to the leakage of inflated air from heat chamber. However the operating display LED was not out of order, even if the temperature was increased up to $160^{\circ}C$.

Image System Using Dual Energy Detector (이중 에너지 검출기를 이용한 영상 시스템)

  • Yeo, Hwa-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3517-3523
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    • 2010
  • Single exposure dual X-ray imaging can be used to separate soft and dense-material images for medical and industrial applications. This study keep focusing baggage inspection system(BIS) specifically. New detector modules for single exposure dual X-ray imaging are consisted of low energy detector (LED) and high energy detector (HED). First, the optimized thickness of copper filter coupled HED to separate low energy and high energy was simulated by the given X-ray energy (140 kVp, 1 mA) using Monte Carlo simulation codes, MCNPX. So as a result of simulation, the copper filter thickness is 0.7 mm. For the design of PIN photodiode, ATLAS device simulation tool was used. 16 channels PIN photodiode of 1.5 mm ${\times}$ 3.2 mm for Dual X-ray imaging detector was fabricated in the process of ETRI. And its dark current and quantum efficiency, terminal capacitance were measured. It was proven that the Lanex Fast B coupled HED were a sufficient candidate to replace the CsI(Tl) commerced in dual X-ray system, since these give a strong signal, overcoming system noise. Finally dual X-ray image was acquired through correction of the LED X-ray Image and the HED X-ray Image.

Development of Dual Energy Radiation Detector (이중 에너지 방사선 검출기 개발)

  • Yeo, Hwa-Yeon
    • Journal of the Korean Society of Radiology
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    • v.4 no.3
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    • pp.5-11
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    • 2010
  • In this paper, we are suggested development of dual-mode detector for dual-energy digital radiography. Design of dual-energy radiography module for commercial BIS (Baggage Inspection System) is used in the spectrum of the X-ray generator and detector for dual-mode features and radiological characteristics were analyzed. BIS suggestl on the image detector module being used to target X-ray tube to simulate X-ray spectrum and simulated spectrum to offer through the new radiographic characteristics of the detector modules were investigated. Using X-ray experiments with an increase in the thickness of the copper filter low energy detector (LED) and high-energy detector (HED) as the difference between the output signal increases. HED, especially in the size of the output signal decreases with increasing thickness of the copper filter was found.

Reducing the Effects of Noise Light in a Visible Light Communication System Using Two Color LEDs (가시광통신 시스템에서 2색 LED를 이용한 잡음광의 영향 감소)

  • Lee, Seong-Ho
    • Journal of Sensor Science and Technology
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    • v.21 no.6
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    • pp.429-433
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    • 2012
  • In this paper, we reduced the optical noise interference in a visible light communication system using two color LEDs. In the transmitter, the original and the inverted signals of the transmitted data modulated a red LED and a blue LED, respectively. In the receiver, a differential detector which is composed of two photodetectors and an optical red filter detected the mixed signal radiated from the two LEDs. In an environment that the optical noise from a fluorescent lamp exists, the signal-to-noise ratio in this system was improved by about 20dB compared to that in the conventional system which uses a single LED and a single photodetector.

Realization of Optical Measurement using White Source and Fourier-domain (고휘도 백색 LED 및 CCD Array Detector를 사용한 Fourier-Domain 방식의 광 계측 시스템 구현)

  • Kim, Kwang-Yoo;Lee, Jung-Rul;Eom, Jin-Seob
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.1
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    • pp.25-30
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    • 2008
  • In this study, the Fourier-Domain optical measurement system, which use a commercial high power white LED as a light source and a CCD linear-array as a detector is realized. The proposed system shows the axial measurement range over $125{\mu}m$ and the axial resolution below $1.24{\mu}m$. This system has the advantage of the cost effective and compact structure and also the better resolution than the existing technologies, which have a resolution above a few of ${\mu}m$ and use bulky and/or expensive broadband light sources.

Noninvasive Hematocrit Monitoring Based on Parameter-optimization of a LED Finger Probe

  • Yoon, Gil-Won;Jeon, Kye-Jin
    • Journal of the Optical Society of Korea
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    • v.9 no.3
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    • pp.107-110
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    • 2005
  • An optical method of measuring hematocrit noninvasively is presented. An LED Light with multiple wavelengths was irradiated on fingernail and transmitted light from the finger was measured to predict hematocrit. A finger probe contained an LED array and detector. Our previous experience showed that prediction accuracy was sensitive to reliability of the finger probe hardware and we optimized the finger probe parameters such as the internal color, detector area and the emission area of a light source based on Design of Experiment. Using the optimized finger probe, we developed a hematocrit monitoring system and tested with 549 persons. For the calibration model with 368 persons, a regression coefficient of 0.74 and a standard deviation of 3.67 and the mean percent error of $8\%$ were obtained. Hematocrits for 181 persons were predicted. We achieved a mean percent error of $8.2\%$ where the regression coefficient was 0.68 and the standard deviation was 3.69.

Development of compact ear inspection probe with fiber-coupled LED (광섬유와 LED를 활용한 소형화된 검이경 개발)

  • Choe, Yeong-Hui;Ma, Hye-Jun;Lee, Ji-Seong;Choe, Eun-Seo
    • Proceedings of the Optical Society of Korea Conference
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    • 2009.02a
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    • pp.527-528
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    • 2009
  • We developed the compact-sized ear inspector utilizing fiber-pigtailed cheap LED light source and CCD(charge coupled detector) camera. With adjusting the lens pair having different focal length respectively, optimized imaging conditions with fiber-coupled LED were obtained.

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The study of the linetracer-developement for the Automatic Guided Vehicle using Infrared LED (적외선 LED를 이용한 무인 주행 저속 전기 자동차용 라인트레이서에 관한 연구)

  • Choi, Sung-Wook;Kim, Seok-Won;Choi, Jae-Ho;Kim, Ho-Seong
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1967-1969
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    • 2003
  • 본 논문에서는 무인 주행 저속 전기 자동차 시스템 개발을 위한 적외선 LED 라인트레이서를 제작하였다. 햇빛에 의한 영향을 제거하기 위해 적외선 LED를 펄스(pulse)로 구동시켰으며 흰색선에서 반사된 적외선 신호를 photodiode를 이용하여 감지하였다. 감지된 신호는 증폭단과 Peak Detector를 거쳐 최종적으로 AVR MCU로 입력이 된 후 여러 상황에 따른 차량의 방향을 결정할 수 있도록 알고리즘를 통해 처리하였다. 실험을 통하여 본 논문에서 제작한 라이트레이서 모듈이 원하는 방향으로 동작함을 확인하였다.

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