• Title/Summary/Keyword: Material Discrimination

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PD Measurement and Pattern Discrimination of Stator Coil for Traction Motor according to Different Defects (결함에 따른 견인전동기 고정자 코일의 부분방전측정 및 패턴분류)

  • Jang, Dong-Uk;Park, Hyun-June;Park, Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.221-222
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    • 2005
  • In this paper, application of NN (Neural Network) as a method of pattern discrimination of PD(partial discharge) which occurs at the stator coil of traction motor was studied. For PD data acquisition, three defective models are manufactured such as internal discharge model, slot discharge model and surface discharge model. PD data for recognition were acquired from PD detector and DAQ board which is able to analysis the PD signal and perform the pattern discrimination. Statistical distributions and parameters are calculated to discriminate PD sources. And also these statistical distribution parameters are applied to classify PD sources by BP and has good recognition rate on the discharge sources.

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PD Source Classification of Model Specimens for GIS (GIS 모의결합의 부분방전원 분류)

  • Park, Sung-Hee;Lim, Kee-Joe;Kang, Seong-Hwa;Lee, Chang-Jun;Lee, Hee-Cheol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05b
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    • pp.100-103
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    • 2004
  • In this paper, BP learning algorithm is studied to apply as a PD source classification in GIS specimens. For occurred partial discharge, three defected models are made; floating particle, surface discharge of spacer, needle to plane. And PD data for discrimination were acquired from PD detector. And these data making use of a computer-aided discharge analyser, statistical and other discharge parameters is calculated to discrimination between different models of discharge sources. And also these parameter is applied to classify PD sources by neural networks. Neural Networks has good recognition rate for three PD sources.

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Sensitivity studies on a novel nuclear forensics methodology for source reactor-type discrimination of separated weapons grade plutonium

  • Kitcher, Evans D.;Osborn, Jeremy M.;Chirayath, Sunil S.
    • Nuclear Engineering and Technology
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    • v.51 no.5
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    • pp.1355-1364
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    • 2019
  • A recently published nuclear forensics methodology for source discrimination of separated weapons-grade plutonium utilizes intra-element isotope ratios and a maximum likelihood formulation to identify the most likely source reactor-type, fuel burnup and time since irradiation of unknown material. Sensitivity studies performed here on the effects of random measurement error and the uncertainty in intra-element isotope ratio values show that different intra-element isotope ratios have disproportionate contributions to the determination of the reactor parameters. The methodology is robust to individual errors in measured intra-element isotope ratio values and even more so for uniform systematic errors due to competing effects on the predictions from the selected intra-element isotope ratios suite. For a unique sample-model pair, simulation uncertainties of up to 28% are acceptable without impeding successful source-reactor discrimination. However, for a generic sample with multiple plausible sources within the reactor library, uncertainties of 7% or less may be required. The results confirm the critical role of accurate reactor core physics, fuel burnup simulations and experimental measurements in the proposed methodology where increased simulation uncertainty is found to significantly affect the capability to discriminate between the reactors in the library.

Material Estimation Method Using Dual-Energy X-Ray Image for Cargo Inspection System (화물 검색 시스템을 위한 듀얼 에너지 X-ray 검색기 영상을 이용한 물질 추정 방법)

  • Lee, TaeBum;Kang, HyunSoo
    • Journal of Korea Society of Industrial Information Systems
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    • v.23 no.1
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    • pp.1-12
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    • 2018
  • This paper presents a material estimation method using dual-energy X-ray images generated as a result of cargo inspection system in MeV region. We use new discrimination curve using logarithmic function rather than four discrimination curves commonly used in existing estimation algorithms. We also propose an atomic number estimation using the probability distribution of the logarithmic curve rather than linear interpolation. When the probability distribution is used as a weight, we used two methods of using the weight for the two nearest reference materials and the weight for all the reference materials. Experimental results showed that the atomic number estimation of materials using the probability distribution as a weight is more accurate than the existing methods. In order to visualize the estimated atomic number, the HSI model was used for color the resulting image.

SNP (Single Nucleotide Polymorphism) Detection Using Indicator-free DNA (비수식화 DNA를 이용한 SNP의 검출)

  • Choi, Yong-Sung;Park, Dae-Hee;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.224-226
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    • 2003
  • In this paper, we succeeded SNP discrimination of DNA hybridization on microarray using new electrochemical system. Using the electrochemical method with a label-free DNA has Performed DNA chip microarray. This method is based on redox of an electrochemical ligand. We developed scanning system with high performance.

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A Study on Analysis of Target Characteristics Using Electromagnetic Waves (전자파를 이용한 목표물의 특성 분석에 관한 연구)

  • Lee, Jonggil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.6
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    • pp.1289-1295
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    • 2015
  • Electromagnetic wave signals radiated from an antenna are reflected by targets and received through the same antenna. These received signals show different characteristics according to various target materials having different dielectric constants. Therefore, target characteristics can be recognized if we can utilize these return signals efficiently. this method can be applied for discrimination and classification of hazardous materials. In this paper, utilizing these experimentally obtained signals, correlation characteristics are obtained and analyzed for classification and discrimination purposes. Although the correlation method requires the storage of reference signals, it shows very promising results. this correlation method can be applied for classification and discrimination of hazardous materials.

Improved fast neutron detection using CNN-based pulse shape discrimination

  • Seonkwang Yoon;Chaehun Lee;Hee Seo;Ho-Dong Kim
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.3925-3934
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    • 2023
  • The importance of fast neutron detection for nuclear safeguards purposes has increased due to its potential advantages such as reasonable cost and higher precision for larger sample masses of nuclear materials. Pulse-shape discrimination (PSD) is inevitably used to discriminate neutron- and gamma-ray- induced signals from organic scintillators of very high gamma sensitivity. The light output (LO) threshold corresponding to several MeV of recoiled proton energy could be necessary to achieve fine PSD performance. However, this leads to neutron count losses and possible distortion of results obtained by neutron multiplicity counting (NMC)-based nuclear material accountancy (NMA). Moreover, conventional PSD techniques are not effective for counting of neutrons in a high-gamma-ray environment, even under a sufficiently high LO threshold. In the present work, PSD performance (figure-of-merit, FOM) according to LO bands was confirmed using a conventional charge comparison method (CCM) and compared with results obtained by convolution neural network (CNN)-based PSD algorithms. Also, it was attempted, for the first time ever, to reject fake neutron signals from distorted PSD regions where neutron-induced signals are normally detected. The overall results indicated that higher neutron detection efficiency with better accuracy could be achieved via CNN-based PSD algorithms.

Classification of stator coil degradation of traction motor by PD signal distribution analysis (PD 분포 분석에 의한 견인전동기 고정자 코일의 열화도 분류에 관한 연구)

  • Park, Seong-Hee;Lim, Jong-Ho;Jang, Dong-Uk;Park, Hyun-June;Kang, Seong-Hwa;Lim, Kee-Joe
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1183-1186
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    • 2004
  • Degradation and insulation failure of traction motor depend on the continuous stress imposed on it. And knowing on insulation condition is important thing for safety operation of EMU(electric multiple unit). In this paper, PD(partial discharge) characteristics for degradation analysis of stator coil is studied. For PD data acquisition, two models are made; one is normal condition coil, the other is aged condition coil. And PD data for discrimination were acquired from PD detector. And these data making use of a computer-aided discharge analyser, statistical and other discharge parameters is calculated to discrimination between different discharge sources. And also these parameter is applied to classify PD sources by neural networks. Neural Networks has good recognition rate for degradation of stator coil.

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Comparative Study of Terminology for Identification of the Chinese Herbal Materia Medica (초본류 한약재 감별을 위한 용어의 비교연구)

  • Shin, Yong-Wook
    • The Korea Journal of Herbology
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    • v.29 no.3
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    • pp.43-50
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    • 2014
  • Objectives : To investigate terminology of Herbal drug discrimination commonly used in China, and it was translated into Korean. It also has been modified to fit the circumstances of the Korean for easier understand for Korean student. Methods : First,Terminology for Identification of the Chinese Herbal Materia Medica (TICHMM) was classified by the appearance, cut surface, material, processing and storage of Herb. Chinese commentary of TICHMM was translated into Korean. Comparative Study was performed based on the Pharmacopoeia of Korea and China. Depending on the meaning of the word, TICHMM was modified to revised Korean expression or remain chinese expression or suggest new Korean expression Result : In the 28 TICHMM terms that describes the shape properties of herbal medicine, 5 was remained in Chinese expression, 22 was modified to revised Korean expression and 1 was suggested in new Korean expression. 8 terms that describes the Section properties of herbal medicine, 6 was modified to revised Korean expression and 2 was suggested in new Korean expression. 3 terms that describes the Material properties of herbal medicine, 1 was remained in Chinese expression, 2 was modified to revised Korean expression. 3 terms that describes the processing and storage properties of herbal medicine, 2 was modified to revised Korean expression and 1 was suggested in new Korean expression. Conclusion : By comparative Study of TICHMM, commonly used in China, it will contribute new guideline on the Visual Examination of Herbal Medicine for Korean student.

Discrimination of Acoustic Emission Signals using Pattern Recognition Analysis (형상인식법을 이용한 음향방출신호의 분류)

  • Joo, Y.S.;Jung, H.K.;Sim, C.M.;Lim, H.T.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.10 no.2
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    • pp.23-31
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    • 1990
  • Acoustic Emission(AE) signals obtained during fracture toughness test and fatigue test for nuclear pressure vessel material(SA 508 cl.3) and artificial AE signals from pencil break and ultrasonic pulser were classified using pattern recognition methods. Three different classifiers ; namely Minimum Distance Classifier, Linear Discriminant Classifier and Maximum Likelihood Classifier were used for pattern recognition. In this study, the performance of each classifier was compared. The discrimination of AE signals from cracking and crack surface rubbing was possible and the analysis for crack propagation was applicable by pattern recognition methods.

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