• Title/Summary/Keyword: detectors

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A Study on the Comparison of Aspirating Smoke Detector and General Smoke Detector Detection Time according to the Fire Speed and Location of Logistics Warehouse through FDS (화재시뮬레이션을 통한 물류창고 화재 속도와 위치에 따른 공기흡입형 감지기와 일반 연기 감지기 감지시간 비교에 관한 연구)

  • SangBum Lee;MinSeok Kim;SeHong Min
    • Journal of the Society of Disaster Information
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    • v.19 no.3
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    • pp.608-623
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    • 2023
  • Purpose: Recently, the number of logistics warehouses has been on the rise. In addition, as the number of such logistics warehouses increases, number of fire accidents also increases every year, increasing the importance of preventing fires in large logistics warehouses. Method: investigated aspirating smoke detectors that are emerging as adaptive fire detectors in logistics warehouses. Then, through fire simulation (FDS), logistics warehouse modeling was conducted to compare and analyze the detection speed of general smoke detectors and aspirating smoke detectors according to four stages of fire growth and three locations of fire in the logistics warehouse. Result: Growth speed in Slow-class fires and Mediumclass fires, the detection speed of aspirating smoke detectors was faster regardless of the location of the fire. However, in Fast-class fires and Ultra-Fast-class fires, it was confirmed that the detection speed of general smoke detectors was faster depending on the location of the fire. Conclusion: It was confirmed that the detection performance of the aspirating smoke detector decreased as the fire growth speed increased and the location of the fire occurred further than the receiver of the aspirating smoke detector. Therefore, even if an aspirating smoke detector is installed in a warehouse that stores combustibles with high fire growth rates, it is judged that an additional smoke detector is attached far away from the receiver of the general smoke detector to increase fire safety.

A Potential Application of Ge (Li) Detectors in Fast Neutron Leakage Spectrum Determination

  • Kang, Chang-Sun
    • Nuclear Engineering and Technology
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    • v.11 no.2
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    • pp.133-136
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    • 1979
  • In the paper it is proposed to use Ge(Li) detectors in determining fast neutron spectra. The spectrum at 691.4 KeV which is produced by the internal conversion of Ge nuclei being broadened by the coincident ionization energy deposited by recoil Ge atoms is proposed to be analysed in estimating the fast neutron spectra.

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Mechanically Modulated Actuators and Branched Finger Detectors for Nano-Precision MEMS Applications

  • Cho, Young-Ho;Lee, Won-Chul;Han, Ki-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.39.1-39
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    • 2002
  • We present nanoactuators and nanodetectors for high-precision Micro Electro Mechanical System (MEMS) applications. Major technical difficulties in the high-precision MEMS are arising from the fabrication uncertainty and electrical noise problems. In this paper, we present high-precision actuators and detectors, overcoming the technical limitations placed by the conventional MEMS technology. For the nano-precision actuation, we present a nonlinearly modulated digital actuator (NMDA). NMDA composed of a digital microactuator and a nonlinear micromechanical modulator. The nonlinear micromechanical modulator is intended to purify the actuation errors in the stroke of the digital a...

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Linear-Quadratic Detectors for Spectrum Sensing

  • Biglieri, Ezio;Lops, Marco
    • Journal of Communications and Networks
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    • v.16 no.5
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    • pp.485-492
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    • 2014
  • Spectrum sensing for cognitive-radio applications may use a matched-filter detector (in the presence of full knowledge of the signal that may be transmitted by the primary user) or an energy detector (when that knowledge is missing). An intermediate situation occurs when the primary signal is imperfectly known, in which case we advocate the use of a linear-quadratic detector. We show how this detector can be designed by maximizing its deflection, and, using moment-bound theory, we examine its robustness to the variations of the actual probability distribution of the inaccurately known primary signal.

A REPORT ON THERMAL LAG OF PAINTED HEAT DETECTORS (도막상태에 따른 열감지기의 감온특성에 관한 시험, 연구)

  • Lee, Bok-Yeong;Yu, In-Ho
    • Fire Protection Technology
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    • s.14
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    • pp.18-33
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    • 1993
  • This report is announced about thermal lag of painted heat detectors. Thermal lag is forecast result from painting the part of heat receiving. It is delayed responsive time to assume fire fighting, escape. Test is simulated that heat detector is painted by synthetic resin emulsion paint according to the circumstance of installation. Painting method, number, thick etc is determined by research worker based on the popular idea.

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Detection of Antineutrinos for Reactor Monitoring

  • Kim, Yeongduk
    • Nuclear Engineering and Technology
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    • v.48 no.2
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    • pp.285-292
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    • 2016
  • Reactor neutrinos have been detected in the past 50 years by various detectors for different purposes. Beginning in the 1980s, neutrino physicists have tried to use neutrinos to monitor reactors and develop an optimized detector for nuclear safeguards. Recently, motivated by neutrino oscillation physics, the technology and scale of reactor neutrino detection have progressed considerably. In this review, I will give an overview of the detection technology for reactor neutrinos, and describe the issues related to further improvements in optimized detectors for reactor monitoring.

A Study on Placement of Point Detectors Based on Homogeneous Section for Travel Time Estimation in National Highway (일반국도 통행시간 추정을 위한 동질구간 기반 지점검지기 배치에 관한 연구)

  • Kim, Seong-Hyeon;Im, Gang-Won;Lee, Yeong-In
    • Journal of Korean Society of Transportation
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    • v.24 no.1 s.87
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    • pp.73-84
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    • 2006
  • This study was carried out to set up the logic to determine lengths of the homogeneous sections effectively in order to provide dynamic travel time on real time base for the application of the model. First, considering real time traffic pattern fluctuation, lengths of the homogeneous sections for each time period and the final homogeneous sections were determined. In order to determine lengths of the homogeneous sections according to traffic condition, the cluster analysis was used based on real time data. In order to verify the homogeneous section the case with detectors in all links and the case with detectors in homogeneous section for each time period are used. As the results of verification, each cases showed similar estimation results. The results of this study are expected to be used for National Highway traffic management and the system to Provide a traffic information in the future. According to this study, when the homogeneous section decision model are used to the ITS project for National Highway, operation cost is expected to be cut by effectively establishing point detectors.

Design and fabrication of power detector for multi-band six-port direct conversion method (다중대역 6단자 직접변환 방식을 위한 전력 검파기 설계 및 제작)

  • Kim, Young-Wan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.10
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    • pp.2194-2200
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    • 2010
  • In this paper, the power detectors using metamaterials were designed and fabricated for multi-band six-port direct conversion method. The RF short-stubs for power detector were designed by using metamaterials which provide multi-band characteristics. The power detectors with metamaterial RF short-stub were analyzed and fabricated by using lumped and distributed element. The measured results of metamaterial power detectors show the good agreement with the simulation results. The performance of lumped-metamaterial RF short-stub shows the insertion loss below 1 dB and the good frequency response characteristics. Also, the distributed-metamaterial RF short-stub shows the good frequency response characteristics and the insertion loss under that of lumped-metamaterial RF short-stub. The multi-band power detectors with metamaterial RF short-stub detect the input RF signal in the designed dual frequency bands very well.