• Title/Summary/Keyword: Spikes

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A study on the characteristics of SPD from PF track circuit (PF궤도회로에서의 서지보호장치 특성연구)

  • Kim, Jong-Ki;Kim, Sun-Ho
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1038-1043
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    • 2010
  • According to the korea standard (KS)'s definition through 'KSC IEC 61643-1(2007), A SPD(Surge Protective Device) is an appliance designed to protect electrical devices from voltage spikes and the principal components used to reduce or limit high voltages can include one or more of the nonlinear components. 4 type of those nonlinear components are utilized in accordance with korea standard's IEC regulation. The SPD is installed the place(in and out side of installation for protecting damage due to the inflow of light surge) which we need by combination of nonlinear components. In this study, the analysis based on the characteristics of SPD from PF track circuit are discussed.

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Analysis of the Irradiated Nuclear Fuel Using the Heavy Atom and Neodynium Isotope Correlations with Burnup

  • Kim, Jung-Suk
    • Nuclear Engineering and Technology
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    • v.29 no.4
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    • pp.327-335
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    • 1997
  • The correlation of isotope composition of uranium, plutonium and neodymium with the burnup in M uranium dioxide fuel has been investigated experimentally. The total and fractional($^{235}$ U) burnup were determined by Nd-148 and, U and Pu mass spectrometric method respectively. The isotope compositions of these elements, after their separation from the fuel samples were measured by mass spectrometric. The content of the elements in the irradiated fuel ore determined by isotope dilution mass spectrometric method using $^{233}$ U, $^{242}$ Pu and $^{150}$ Nd as spikes. The content of plutonium in the irradiated fuel was expressed by the correlation with uranium isotopes. The correlations between isotope compositions themselves and the total and fractional burnup ore compared with those calculated from ORIGEN2 code.

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Flicker Prevention Through Transition-Frequency Modulation in Visible Light Communication (가시광통신에서 천이주파수 변조를 이용한 플리커 방지)

  • Lee, Seong-Ho
    • Journal of Sensor Science and Technology
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    • v.29 no.4
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    • pp.243-248
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    • 2020
  • In this study, we applied transition-frequency modulation to prevent the flickering of light-emitting diodes (LEDs) in visible light communication (VLC). In the VLC transmitter, rectangular waveforms with transition frequencies of four and two in each bit time were used for the high and low bits, respectively, in the non-return-to-zero data. In the VLC receiver, an RC-high-pass filter (HPF) was used to eliminate the interference of the 120 Hz noise light from the adjacent lighting lamps, and an SR-latch circuit was used to recover the transmitted signal using spikes from the output of the RC-HPF. This configuration is useful for constructing VLC systems that are flicker-free and resistant to adjacent noise light interference.

A Study on the Transient Analysis of Coupled Lines and Ability of Crosstalk Suppression Inherent to Nonuniform Lines (결합선로의 과도해석과 불균일선로에 잠재된 누화 억압 능력에 관한 연구)

  • 권중훈;이병희;박의준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.3
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    • pp.464-473
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    • 2000
  • The method is presented which predicts voltage waveforms at each nodes inter-connected arbitrarily on the coupled transmission lines by extracting the node connection condition to be included in the modal telegrapher's equation, hence analyzing the mechanism of waveform propagation on transmission lines. It is shown that it is also possible to analyze efficiently the coupled nonuniform lines. And then the nonuniformity of coupled lines is demonstrated for suppressing the crosstalk spikes using the one-dimensional inverse-scattering control theory. The predicted waveforms by presented method are analyzed and verified by comparison with those by the generalized S-parameter technique.

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A Study on 600 V Super Junction Power MOSFET Optimization and Characterization Using the Deep Trench Filling (Deep Trench Filling 기술을 적용한 600 V급 Super Junction Power MOSFET의 최적화 특성에 관한 연구)

  • Lee, Jung-Hoon;Jung, Eun-Sik;Kang, Ey-Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.4
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    • pp.270-275
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    • 2012
  • Power MOSFET(metal oxide silicon field effect transistor) operate voltage-driven devices, design to control the large power switching device for power supply, converter, motor control, etc. But on-resistance characteristics depending on the increasing breakdown voltage spikes is a problem. So 600 V planar power MOSFET compare to 1/3 low on-resistance characteristics of super junction MOSFET structure. In this paper design to 600 V planar MOSFET and super junction MOSFET, then improvement of comparative analysis breakdown voltage and resistance characteristics. As a result, super junction MOSFET improve on about 40% on-state voltage drop performance than planar MOSFET.

Calcium-activated chloride channels: a new target to control the spiking pattern of neurons

  • Ha, Go Eun;Cheong, Eunji
    • BMB Reports
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    • v.50 no.3
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    • pp.109-110
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    • 2017
  • The nature of encoded information in neural circuits is determined by neuronal firing patterns and frequencies. This paper discusses the molecular identity and cellular mechanisms of spike-frequency adaptation in the central nervous system (CNS). Spike-frequency adaptation in thalamocortical (TC) and CA1 hippocampal neurons is mediated by the $Ca^{2+}$-activated $Cl^-$ channel (CACC) anoctamin-2 (ANO2). Knockdown of ANO2 in these neurons results in increased number of spikes, in conjunction with significantly reduced spike-frequency adaptation. No study has so far demonstrated that CACCs mediate afterhyperpolarization currents, which result in the modulation of neuronal spike patterns in the CNS. Our study therefore proposes a novel role for ANO2 in spike-frequency adaptation and transmission of information in the brain.

Paroxysmal kinesigenic dyskinesia in a patient with a PRRT2 mutation and centrotemporal spike discharges on electroencephalogram: case report of a 10-year-old girl

  • Seo, Sun Young;You, Su Jeong
    • Clinical and Experimental Pediatrics
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    • v.59 no.sup1
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    • pp.157-160
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    • 2016
  • Coexistence of paroxysmal kinesigenic dyskinesia (PKD) with benign infantile convulsion (BIC) and centrotemporal spikes (CTS) is very rare. A 10-year-old girl presented with a 3-year history of frequent attacks of staggering while laughing and of suddenly collapsing while walking. Interictal electroencephalogram (EEG) revealed bilateral CTS, but no changes in EEG were observed during movement. The patient's medical history showed afebrile seizures 6 months after birth, while the family history showed that the patient's mother and relatives on the mother's side had similar dyskinesia. Genetic testing demonstrated that the patient had a heterozygous mutation, c.649_650insC, in the PRRT2 gene. To our knowledge, this constitutes only the second report of a patient with PKD, BIC, CTS, and a PRRT2 mutation.

D-UPFC Application as the Series Power Device in the Massive Roof-top PVs and Domestic Loads

  • Lee, Kyungsoo
    • Current Photovoltaic Research
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    • v.4 no.4
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    • pp.131-139
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    • 2016
  • This paper shows the series power device in the massive roof-top PVs and domestic loads. D-UPFC as the series power device controls the distribution voltage during voltage rise (or fall) condition. D-UPFC consists of the bi-directional ac-ac converter and the transformer. In order to verify the D-UPFC voltage control, the distribution model is used in the case study. D-UPFC enables the voltage control in the distribution voltage range. Dynamic voltage control from voltage rise and voltage fall conditions is performed. Scaled-down experimental test of the D-UPFC is verified the voltage control and it is well performed without high voltage spikes in the inductive load.

The Detection of Epileptic Spikes in EEG using Neural Network (신경망과 웨이브렛 변환을 이용한 뇌전도의 간질 극파 검출)

  • 최혜원;이성수;윤영로
    • Journal of Biomedical Engineering Research
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    • v.20 no.6
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    • pp.555-560
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    • 1999
  • 간질은 신경세포의 일부가 짧은 시간동안 과도한 전기를 발생시킴으로써 일어나는 신경계의 발작적 증상으로 배경 활동파와는 구별되는 극파, 예파, 예파와 서파를 동반한 극서파 복합(sharp and slow complexes)의 뇌파 특징파를 갖는다. 장시간의 뇌파기록에서 시간의 절약과, 정량화를 위해 컴퓨터를 이용한 간질 파형의 자동 검출은 객관성을 높이고 정량적인 해석을 위해 필수적이다. 본 연구에서는 간질 뇌파를 검출하기 위해 웨이브렛 변환과 신경망을 사용하였다. 웨이브렛 변환은 잡음을 제거하고 간질 뇌파의 특징을 강조하며 신경망의 입력노드수를 줄였다. 전문가에 의해서 분류된 간질특성과 정상뇌파를 신경망에 입력시켜 최적의 신경망구조를 선택하였고, 검출 문턱치를 설정하였다. 신경망은 200ms(26개의 데이터포인트)신호의 웨이브렛 결과와 웨이브렛 변환후 데이터 상의 최대, 최소 기울기가 입력되어 전체 28개의 입력 노드로 구성하였다. 은닉층은 18노드, 문턱치값은 민감도와 선택도가 일치하는 0.65가 사용되었다. 결과로 임상 환자 데이터에 입력되어 78.54% 의 검출률을 보였다.

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Classification of Multi-Unit Neural Action Potential by Template Learning (학습 가능한 실시간 다단위 신경 신호의 분류에 관한 연구)

  • Kim, S.D.;Kim, K.H.;Kim, S.J.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.99-102
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    • 1997
  • A neural spike sorting technique has been developed that also has the capability of template learning. A system of software has been written that first obtains the templates by learning, and then performs the sorting of the spikes into single units. The spike sorting can be done in real time. The template learning consists of spike detection based on the discrete Haar transform (DHT), feature extraction by clustering of spike amplitude and duration, classification based on rms error, and fabrication of templates. The developed algorithms can be implemented into real time systems using digital signal processors.

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