• Title/Summary/Keyword: Counting System

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MEASUREMENT OF THE D-D NEUTRON GENERATION RATE BY PROTON COUNTING

  • Kim, In-Jung;Jung, Nam-Suk;Choi, Hee-Dong
    • Nuclear Engineering and Technology
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    • v.40 no.4
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    • pp.299-304
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    • 2008
  • A detection system was set up to measure the neutron generation rate of a recently developed D-D neutron generator. The system is composed of a Si detector, He-3 detector, and electronics for pulse height analysis. The neutron generation rate was measured by counting protons using the Si detector, and the data was crosschecked by counting neutrons with the He-3 detector. The efficiencies of the Si and He-3 detectors were calibrated independently by using a standard alpha particle source $^{241}Am$ and a bare isotopic neutron source $^{252}Cf$, respectively. The effect of the cross-sectional difference between the D(d,p)T and $D(d,n)^3He$ reactions was evaluated for the case of a thick target. The neutron generation rate was theoretically corrected for the anisotropic emission of protons and neutrons in the D-D reactions. The attenuations of neutron on the path to the He-3 detector by the target assembly and vacuum flange of the neutron generator were considered by the Monte Carlo method using the MCNP 4C2 code. As a result, the neutron generation rate based on the Si detector measurement was determined with a relative uncertainty of ${\pm}5%$, and the two rates measured by both detectors corroborated within 20%.

Study of a Method for Measuring Hydrogen Gas Concentration Using a Photon-counting Raman Lidar System (광 계수 방식의 라만 라이다 시스템을 이용한 원격 수소 가스 농도 계측 방법에 대한 연구)

  • Choi, In Young;Baik, Sung Hoon;Cha, Jung Ho;Kim, Jin Ho
    • Korean Journal of Optics and Photonics
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    • v.30 no.3
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    • pp.114-119
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    • 2019
  • This paper discusses the development of a Raman lidar system for remote detection and measurement of hydrogen gas by using a photon counter. The Raman signal of the hydrogen gas is very weak and has a very low signal-to-noise ratio. The photon counter has the advantage of improving the signal-to-noise ratio, because it has a discriminator to eliminate the background noise from the Raman signal of the hydrogen gas. Therefore, a small and portable Raman lidar system was developed using a low-power pulsed laser and a photon-counter system to measure the hydrogen gas concentration remotely. To verify the capability of measuring hydrogen gas using the developed photon-counting Raman lidar system, experiments were carried out using a gas chamber in which it is possible to adjust the hydrogen gas concentration. As a result, our photon-counting Raman lidar system is seen to measure a minimum concentration of 0.65 vol.% hydrogen gas at a distance of 10 m.

Gap Control Using Discharge Pulse Counting in Micro-EDM (미세 방전 가공에서의 방전 펄스 카운팅을 이용한 간극 제어)

  • Jung J.W.;Ko S.H.;Jeong Y.H.;Min B.K.;Lee S.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.499-500
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    • 2006
  • The electrode wear in micro-EDM significantly deteriorates the machining accuracy. In this regard, electrode wear needs to be compensated in-process to improve the product quality. Therefore, there are substantial amount of research about electrode wear. In this study a control method for micro-EDM using discharge pulse counting is proposed. The method is based on the assumption that the removed workpiece volume is proportional to the number of discharge pulses, which is verified from experimental results analyzing geometrically machined volume according to various number of discharges. Especially, the method has an advantage that electrode wear does not need to be concerned. The proposed method is implemented to an actual micro-EDM system using high speed data acquisition board, simple counting algorithm with 3 axis motion system. As a result, it is demonstrated that the volume of hole machined by EDM drilling can be accurately estimated using the number of discharge pulses. In EDM milling process a micro groove without depth variation caused by electrode wear could be machined using the developed control method. Consequently, it is shown that machining accuracy in drilling and milling processes can be improved by using process control based on the number of discharge pulses.

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Three-Dimensional Visualization and Recognition of Micro-objects using Photon Counting Integral Imaging Microscopy (광자 계수 집적 영상 현미경을 사용한 마이크로 물체의 3차원 시각화와 인식)

  • Cho, Myungjin;Cho, Giok;Shin, Donghak
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.5
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    • pp.1207-1212
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    • 2015
  • In this paper, we propose three-dimensional (3D) visualization and recognition techniques of micro-objects under photon-starved conditions using photon counting integral imaging microscopy. To capture high resolution 2D images with different perspectives in the proposed method, we use Synthetic Aperture Integral Imaging (SAII). Poisson distribution which is mathematical model of photon counting imaging system is used to extract photons from the images. To estimate 3D images with 2D photon counting images, the statistical estimation is used. Therefore, 3D images can be obtained and visualized without any damage under photon-starved conditions. In addition, 3D object recognition can be implemented using nonlinear correlation filters. To prove the usefulness of our technique, we implemented the optical experiment.

A Study on Audience Counting Method in Auditorium Based on Pattern Comparison (패턴비교를 이용한 공연장에서의 관객 수 카운팅 방법에 관한 연구)

  • Sim, Sang-Kyun;Park, Young-Kyung;Kim, Joong-Kyu
    • The KIPS Transactions:PartB
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    • v.14B no.1 s.111
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    • pp.13-22
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    • 2007
  • In this paper, we propose an audience counting method in an auditorium based on pattern comparison. The previous counting methods based on object detection can't exactly count the audience in real time because auditorium has coarse illumination condition and so many audiences. Therefore, in this paper, we count the audience in an auditorium with fixed seats by the method which the pattern from each reference seat is compared to the pattern from each input seat. Especially, to overcome limitations based on either illumination or noise, two pattern comparison methods are efficiently employed and combined. One is based on the amplitude projection, and the other is based on Walsh-Hadamard Kernel. Walsh-Hadamard Kernel has the characteristic which complements amplitude projection. Therefore, we ran achieve the accurate counting in the presence of coarse illumination and noise. The experimental results show that our method performs well on sequences of images acquired in an auditorium. We also verify a realistic possibility for other applications applying our method to the parking positioning system.

The Effects of Breath-Counting Meditation and Deep Breathing on Heart Rate Variability

  • Kim, Ji-Hwan;Bae, Hyo-Sang;Park, Seong-Sik
    • The Journal of Korean Medicine
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    • v.37 no.2
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    • pp.36-44
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    • 2016
  • Objectives: This study aimed to evaluate the effects of breath-counting meditation (BCM) and deep breathing (DB) on heart rate variability (HRV). These breathing techniques have the characteristics of non-paced and self-controlled breathings, resulting in less increase of HRV. We also compared BCM and DB with usual breathing (UB) or relaxing breathing (RB) which can reveal the characteristics of those. Methods: 83 healthy volunteers sitting in chairs performed non-paced breathing; UB, RB, BCM, and DB each for 5 minutes. One minute of relaxation was permitted between breathings. Participants surfed the internet sitting in front of a computer during UB, while for RB, they remained steady with eyes closed. For BCM, they breathed inwardly counting from 1 to 10 repetitively, while they took a deep breath during DB. Physiological indices were simultaneously recorded with a biofeedback system. Results: Respiration rate, thoracic amplitude, and mean heart rate decreased in RB compared with UB, but there was no change in HRV. Respiration rate in BCM and DB was lower than that in UB or RB, and the amplitude of thorax or abdomen, and HRV all increased (p<0.05). However, mean heart rate and skin conductance decreased in BCM compared with UB (p<0.05), whereas those were no different between DB and UB. Conclusion: BCM, just concentrating mentally on breathing with counting each breath, can increase HRV with less sympathetic activation, while DB, actively moving thorax and abdomen for achieving the deepest respiration rate, can greatly raise HRV with the maintenance of mean vagal or sympathetic tone.

A Study on the Counter Program of the Radiation Detector Using 8051 Micro-controller (8051 마이크로 콘트롤러를 이용한 휴대용 방사능 측정기의 카운터 프로그램 연구)

  • Kim, Yong-Duk;Park, Se-Kwang
    • Journal of Sensor Science and Technology
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    • v.6 no.3
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    • pp.228-236
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    • 1997
  • Radioactive materials need to control, measure and protect precisely the overflow because they are dangerous. In this paper, GM-counter type radiation detector system, that can precisely measure the quantity of radioactivity using improved counting program is designed and program that can store and transfer the counted data is studied. The manufactured system, counting system of GM-counter type radiation detector, and counter program can be utilized to measure them at various methods in an atomic power plant and research centers.

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Development of Drive for BLDC Motor Using Resolver (레졸버를 이용한 BLDC 모터의 드라이브 개발)

  • Lee, G.Y.;Lee, C.H.;Kim, S.B.;Kwon, S.J.
    • Journal of Power System Engineering
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    • v.3 no.2
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    • pp.64-69
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    • 1999
  • The paper shows a result for development of BLDC motor drive by using a resolver as position detection sensor. The developed drive use a method detecting rotor position based on HSI interrupt function of microprocessor without a specialized counting circuit. The algorithm generating three-phase PWM wave to change switching voltage and current is realized based on single chip microprocessor. The PWM generating part and position counting circuit are realized by software technique without usage of conventional analogue circuit or object-oriented chips. So the drive system become compact. The effectiveness of the developed drive is verified by experimented results of speed response for step reference input.

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