• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.49-52
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• 2003

Two types of ozone monitors using UV absorption method were tried in consideration of cost of the monitor and precision in measuring. The high concentration ozone monitor for high concentration real time ozone monitoring from ozone generator was composed of a low pressure mercury lamp as UV source, a photo multiplier tube as UV detector and signal processing unit for the most part. This structure could be very useful for low price high concentration ozone monitor due to simple system structure and fairly good monitoring characteristics. The developed system showed good linear output characteristics to ozone in the measuring concentration range of 0.05 and 2 wt.%. For accuracy ambient ozone monitoring in ambient in ppm level, the system composed of a high power pulsed xenon lamp as UV source, an optical spectrometer with a high sensitivity linear CCD array as UV detector and signal processing unit in brief speaking was proposed our study for the first time in the world. The developed system showed good linearity and sensitivity in relative low measuring range between 10ppm and 10,000ppm, and showed some feasibility of high resolution ozone monitor using CCD array as photodetector.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.2
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• pp.45-53
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• 2004

We measured biophoton emissions from seven acupuncture points of eight healthy subjects. The measured points are the Yintang, the $Danch{\bar{u}}$, the Shinketsu, the left and right $R{\bar{o}}ky{\bar{u}}$ and the left and right Yaotongwue of hands. The photo multiplier tube (H-610805s, Hamamatsu, Japan) has spectral range between 300nm and 650nm. Significantly low emission rate was observed at the Shinketsu where the rate was $3.7\;{\pm}\;1.8\;cps$. On the average the highest emission was from the Yaotongxue points where the rate was $11.3\;{\pm}\;5.4$. The high correlation between the left and right hands, and the low correlation between different points are consistent with previous reports.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2122-2126
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• 2007

A special PM-Tube(Photo Multiplier Tube) that is using the photoelectric effect has been designed and manufactured to measure the radiation energy of arc in a gas circuit breaker(GCB). The PM-Tube, LLG(liquid light guides), ND(neutral density) filter, and a model gas circuit breaker have been combined for the reception and the transmission of the light and a simplified synthetic test facility with the arc energy measuring system has been established. In the case of $SF_6$ gas pressure $5kg.f/cm^2$ and arc length 20mm, the radiation energy increases with the arc current but it tend to be saturated in the above 20kA. Under the arc current 20kA, the total radiation energy has the biggest value around 8kA and was not exceeded 40% of the total arc energy.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.7
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• pp.289-296
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• 1985

The Townsend primary ionization coefficient a was measured by the luminous-flux method using the fact that the intensity of radiant light is proportional to electron density in the townsend discharge domain. The ranges of measurements were 15for He gas and 10

• Journal of IKEEE
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• v.21 no.2
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• pp.146-149
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• 2017

In this paper, we propose a wide-range radiation measurement system using GM Tube and NaI(TI) detector. The proposed system is designed as a small module optimized to control and count the detector signal of NaI(Tl) Detector and GM Tube. The radiation dose is measured in a wide-range 0.1uSv/h to 10mSv/h in conjunction with two detectors, and two detectors operate simultaneously at 10uSv/h to 100uSv/h, where the measurement interval overlaps. The radiation dose was selected using a wide-range radiation measurement algorithm that controls the on/off function of the detector in the appropriate interval for the overlapped radiation measurable interval. In order to evaluate the performance of the proposed system, it has been confirmed that the measurement uncertainty of each section is measured as ${\pm}7.5%$ and it operates normally under ${\pm}15%$ of the international standard.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.293-297
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• 2012

CsI:Gd crystal was grown by the Bridgeman method and its scintillation properties were investigated. The wavelength peak of the luminescence spectrum for the crystal excited by X-ray was 419 nm. The range of the spectrum was from 300 nm to 800 nm. The spectrum well matched to the quantum efficiency of a typical bi-alkali photo-multiplier tube(PMT). An energy resolution of 48.2 % was obtained for 662 keV ${\gamma}$-rays of $^{137}Cs$. The three decay times were obtained as a fast(557.4 ns, 42.2 %), intermediate (1.78 ${\mu}s$, 29.7 %) and slow (5.43 ${\mu}s$, 28.1 %) components, respectively.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.301-304
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• 2008

This paper presents the experimental results on breakdown characteristics in $N_2$ gas under non-uniform electric fields caused by both the positive and negative lightning impulse voltages. $N_2$ gas have an advantage of eco-friendly and cost reduction, and safety aspects. In order to analyze the impulse pre-breakdown processes in $N_2$ gas, we carried out measurements and observations of the impulse breakdown voltages, pre-breakdown current and luminous signals. They were measured by a voltage divider, a shunt and a photo-multiplier tube, respectively. Additionally, the characteristics of discharge channels were observed by high speed cameras. The breakdown voltages in the positive polarity was lower than those in the negative polarity.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.129-132
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• 2004

This paper presents an experimental study on the prebreakdown characteristics in $SF_6/N_2$ mixtures under non-uniform electric fields when subjected to the positive and negative lightning impulse voltages. $SF_6/N_2$ mixtures have a merit of an environmental aspect and cost reduction, and safty aspects. In order to analyze the prebreakdown processes in $SF_6/N_2$ mixtures stressed by impulse voltages, prebreakdown current and light were observed by a shunt with high sensitivity and a photo-multiplier tube, respectively. Additionally, characteristics of luminous events in flashovers were discussed.

• The Journal of the Acoustical Society of Korea
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• v.40 no.5
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• pp.408-416
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• 2021

In the ultrasonic dispersion, in order to avoid direct contact of the radiation surface of ultrasonic transducers with a liquid sample, the liquid sample is separated by a glass container and it receives ultrasonic energy through an acoustic medium. The transmission efficiency of the ultrasonic energy in the multi-layered ultrasonic system is an important factor. In this study, we suggested a method that can improve the ultrasonic energy transfer efficiency by using a propylene glycol solution as a liquid matching layer in the multi-layered acoustic system. In this method, a propylene glycol solution was filled between the Langevin-type ultrasonic transducer and the luminol solution and the sonoluminescence phenomena in the luminol solution, which is caused by nonlinear effect of high power ultrasound radiated from the transducer, was examined by using a Photo Multiplier Tube (PMT). The transmission efficiency depending on the concentration of propylene glycol solution was observed, and we can see that as the concentration of the propylene glycol solution increased, the matching effect increased while the acoustic attenuation increased. It was confirmed that there is an optimal concentration compromised these two conflicting conditions, and the optimum concentration of the propylene glycol solution was determined experimentally.

• Journal of the Korean Society of Combustion
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• v.4 no.1
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• pp.27-38
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• 1999

We constructed a wire-cylinder type pulsed corona discharge system for $NO_x$ removal, which was operated in room temperature. A emission spectrometer was built with a boxcar averager and monochrometer equipped with photo-multiplier tube detector. The sensitivity of the emission spectrometer was greatly improved by synchronizing the emission spectrometer with pulsed corona discharge system using a triggered spark-gap switch. $N_2$ spectrum($c^3{\Pi}_u{\rightarrow}X^1{\Sigma}_g{^+}$) was measured in the range of 300 - 450 nm and oxidizing OH radical emission($A^2{\Sigma}^+{\rightarrow}X^2{\Pi}$) was measured in case $N_2$ was supplied with water bubbling. As wet gas composition of inlet $N_2$ supplied in the discharge system increased, the intensity of OH emission was increased and saturated at wet gas composition 50%. We also investigated additive effect of $C_2H_4,\;H_2O,\;H_2O_2$ on the intensity of OR emission and $NO/NO_2/NO_x$ reduction and analysed the related reaction mechanism in corona discharge process. $H_2O_2$ additive increased the intensity of OH emission and $NO/NO_x$ reduction.