• Title/Summary/Keyword: detectors

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The development of UV falme detector (UV 화재감지장치 개발)

  • Gwon, O-Seung;Jeong, Chang-Gi;Lee, Bok-Yeong
    • Fire Protection Technology
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    • s.28
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    • pp.48-54
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    • 2000
  • The technique detects radiant energy form a flaming fire of fuels contained carbonaceous material can be applied to fast growing fires. This technique applied detectors are ultimately effective when early detecting fire alarm system is required or the smoke and heat detectors can not applied. In Korea Fire regulation, a flame detector should be install in case that the installation height is higher than 20[m], chemical plant, hangar refinery. Therefore it is really necessary that a flame detector has to be developed as soon as possible. With foundation technique of flame detector, ideal sensing element and stable circuit design, a trial UV flame detector is manufactured. The stable and reliable technique of flame detector is established through the repeateed perfomance test and modification. An early detecting fire alarm device is developed through the modification, supplement of the structure and circuit. Results of the R & D for the manufacture of an excellent flame detecting device is carried out with the establishment of technique for the mass production and the qualified manufacturing process.

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Installed Spacing and Reponse Time Index of Heat Detection Devices (열감지장치의 응답시간지수와 경계구역)

  • 권오승;이복영;김동석
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1996.11a
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    • pp.72-75
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    • 1996
  • The objectives of this paper investigate the effect of installed spacing on the activation of spot type heat detection devices. The flow of hot gases under a ceiling resulting from the impingement of a fire plume activates heat detectors and sprinklers. Local temperature and velocity in this ceiling jet are usually expressed with the function of a ceiling height, the distance from a fire location and the heat release rate of fire. And detectors having different. RTI respond in different ways to the same temperature and velocity of ceiling jet. Thus great care should be taken to decide installed spacing of heat detection devices by considering above effects.

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Gravitational-wave detection - for the new age of astronomy (중력파 검출 - 새로운 천문학의 시대를 위하여)

  • Oh, John J.
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.58.1-58.1
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    • 2015
  • Gravitational-wave has been predicted by Einstein's general relativity in 1916, but its direct detection has failed to date despite of the persistent efforts in the last fifty years in the ground-based gravitational wave detectors. In the centennial year of the birth of general relativity, 'advanced LIGO', one of the most promising Earth-based gravitational wave detectors, plans to start commissioning for the successful discovery of gravitational waves. In addition, a pathfinder satellite of eLISA project, a space-based GW antenna by European Space Agency (ESA), will be launched in the mid of this year. In this talk, we review the current status of gravitational waves detection experiments and discuss its scientific impacts and the possibility of opening the new age of astronomy.

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Field tests of the radiation detectors for environmental radiation monitoring around KORI nuclear power plants (고리원자력 주변 환경방사선 감시를 위한 방사선 측정기의 현장 성능 시험)

  • 최성수;신대용;조규성;하달규
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1371-1374
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    • 1997
  • We had developed the on-line environmental monitoring system which has installed around Kori Nuclear Power Plants and will be taken the place of the existing system. The system consists of a main computer and 11 sets of radiation monitoring post equipments. Nal(Tl) scintillation detectro was adopted in addition to ion-chamber detector and implemented with DCU(Dose Conversion Unit) and SCA(Single Channel Analyzer). Compared with the existing system, it has revised feature in the radiation measurements which are detection of artificial radioactivity and 2-ways of the radiatiion detectors. The field test trsults show that the developed radiation detecting equipments can measure environmental radiation withn 5.0% of the theoretical value.

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A Two-dimensional Numerical Simulation of Self-signal Processing Infrared Detectors (자기신호처리 적외선 감지소자의 2차원 수치해석)

  • 조남홍;곽계달
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.11
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    • pp.52-62
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    • 1995
  • We developed a two-dimensional numerical simulator which can analyze the electrical as well as optical characteristics and evaluate the detection performances of self-signal processing infrared detectors. It solves the poisson equation and the electron, hole current continuity equations including the optical generation and recombination models. To speed up convergency rate. the Newton algorithm is used. Automatic triangular grid generator make it easy to simulate the devices with the various read-out geometries. This simulator can show the variation of spatial resolution which is caused by the transit velocity and transit time dispersion in bifurcate and horn geometries respectively. Also, we calculated the responsivity, noise, and detectivity in respect of the applied electric field and background field-of-view. The results obtained from simulation correspond to those of experiments, and it is verified that horn read-out geometry has the superior spatial resolution and detection performance to bifurcate geometry.

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Improving Sensitivity of the Pyroelectric Infrared Flame Detector (초전형 적외선식 불꽃감지기의 감도특성 개선)

  • Song, Hyun Seon;Lee, Yeu Yong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.4
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    • pp.77-84
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    • 2015
  • PZT ceramics, usually used pyroelectric materials exhibited a relatively highly Curie temperture(Tc) of $250-450^{\circ}C$ and permittivity constant of 500-1600. In this paper, the pyroelectric infrared detectors are applied two different types of pyroelectric materials, that is tetragonal crystal of ferroelectric $PbTiO_3$ and rhombohedral crystal of $Pb(Zr,Ti)O_3$. PZT ceramics shows not only highly Curie temperture but also excellent pyro and piezoelectric properties at the Zr/Ti(=52/48) ratio. Therefor in this paper, the pyroelectric infrared detectors are applied PZT ceramics, and obtained sensitive sensing characteristics by expriment case studies.