• Title/Summary/Keyword: 중성점

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Algorithm for Switch Open Fault Detection of Asymmetric 6-phase PMSM Based on Stationary Reference Frame dq-axis Currents (비대칭 6상 영구자석 동기 전동기의 정지 좌표계 DQ축 전류를 이용한 스위치 개방 고장 검출 기법)

  • Lee, Won-Seok;Kim, Han-Eol;Hwang, Seon-Hwan;Lee, Ki-Chang;Park, Jong-Won
    • Journal of IKEEE
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    • v.26 no.2
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    • pp.265-270
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    • 2022
  • This paper proposes the detection algorithm for switch open fault of asymmetric 6-phase PMSM based on stationary reference frame dq-axis currents. In this paper, target motor has an asymmetric structure in which two upper three windings have an electrical phase difference of 30° and a neutral point is separated. As a result, dual 3-phase PWM inverters and the detection techniques due to open failures of switch are definitely required. In this paper, the dual dq-axis current control method is used for driving the asymmetric 6-phase PMSM and the open fault switch should be detected by using variable all pass filter and low pass filter in order to detect the current amplitude. The effectiveness and usefulness of the proposed method is verified by several experiments.

고준위 폐기물 지하처분연구시설 부지 특성에 관한 연구

  • 김건기;권상기;조원진;박정화
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.226-227
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    • 2004
  • 본 연구에서는 원자력 연구소 내에 건설할 고준위 폐기물 지하처분연구시설 부지에 관한 특성을 파악하고, 연구시설의 위치를 선정하기 위한 지질학적 연구를 실시하였다. 지표지질조사를 통하여 연구소 내에 분포하는 암석들의 분류와 선구조 분석을 실시하였고, 지구물리탐사와 시추조사를 통한 지하 암반의 분포양상과 연구시설 주변의 추정되는 파쇄대의 분포를 확인하였다. 지표지질조사결과 복운모화강암과 화강섬록암질 편마암이 점이적인 관계로 분포하고 있으며 (Fig.1, 3), 이들 화강암류 내에는 암맥상으로 중성 혹은 염기성 암맥들이 절리의 방향과 동일하게 관입 분포한다. 절리의 방향성은 N30E, N80W, NS방향으로 분포하고 있다(Fig. 2).(중략)

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울진 2호기 5주기 저출력 노물리 시험에서의 감마 Background 의 영향 분석

  • 송재웅;김용래
    • Nuclear Engineering and Technology
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    • v.28 no.2
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    • pp.197-205
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    • 1996
  • 울진 2호기 5주기 노물리 시험 결과 기준 제어군의 제어능과 기준 제어군 삽입 전후의 붕소 농도의 차이의 비로 정의되는 평균 붕소능의 측정 결과가 제한치를 위배하였다. 이것은 노물리 시험시 사용하는 노외 계측기가 비보상형 전리함이기 때문에 중성자속 준위가 낮을 때 감마 background 에 의한 영향이 커지며, 이런 경우에 발생될 수 있는 현상으로 판명되었다. 따라서 본 연구에서는 이러한 감마 background로 인한 반응도 증가 현상을 분석하기 위해 점 동특성 방정식을 수치 해석적으로 풀고 이로부터 감마 background가 없을 때의 기준 제어군 제어능 측정 시험을 모사 계산하였다. 이러한 방법으로 계산한 결과, 기준 제어군의 예상 측정제어능이 실제 측정치보다 약 6%증가하였으며 이 값을 사용하여 평균 붕소능을 계산한 바에 의하면 그 제한치를 만족하는 것으로 평가되었다.

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미임계 증배 집합체를 이용한 BNCT용 열외중성자빔의 설계

  • 한치영;김도헌;김종경
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05b
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    • pp.746-751
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    • 1998
  • 붕소 중성자 포획 요법(BNCT, Boron Neutron Capture Therapy)용 열외중성자빔의 개발을 위하여 방사성 동위원소인 Cf-252를 중성자 선원으로 사용하였으며 상대적으로 낮은 중성자속을 높이기 위하여 미임계 증배 집합체를 이용하였다. 이전에 계시된 미임계 증배 집합체는 높은 핵연료 농축도를 필요로 하는 단점이 있어 본 연구에서는 이를 감소시키기 위한 몇 가지 설계안을 제시하였다. 중성자빔 설계를 위하여 몬테칼로 방법을 이용한 전산코드인 MCNP를 이용, 타원형두뇌 팬텀 내에서 AD, AR ADDR및 각각의 선량성분 등을 계산함으로써 설계된 중성자빔의 특성분석을 수행하였다. 새롭게 개선되어 제시된 중성자빔의 설계는 상대적으로 낮은 핵연료 농측도를 보이면서 기존의 결과와 유사한 결과를 보여주고 있으며 특히 두뇌 팬텀 내에서의 선량률은 기존에 비해 매우 높은 값을 보임으로써 짧은 시간에 효과적으로 뇌종양을 치료할 수 있는 이 점이 있다.

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Introduction of Distribution system planning for Microgrids (마이크로그리드 도입 시 배전계통 계획에 대한 고찰)

  • Choi, In-Sun;Choi, Young-Jun;Park, Jung-Sung;Shin, Hye-Kyeong
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.145-146
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    • 2008
  • 중국, 인도의 경제 발전 등의 요인으로 인해 고유가 시대가 계속될 것으로 전망되고 있으며, 기후 환경 문제로 인해 신재생 에너지 사업이 큰 부가가치를 지닌 사업으로 부각할 것이다. 이에 분산전원에 대한 관심도는 커지고 있으나, 분산전원이 계통에 연계되기 위해서는 해결해야 할 문제가 너무 많다. 이를 해결할 수 있는 방안으로 마이크로 그리드에 대한 관심이 지속되고 있으며 많은 연구가 진행되고 있다. 본 논문에서는 기존의 배전계통 계획 기법에 대해 분석하고, 마이크로그리드가 도입되기 위해서 배전계통 계획 시 고려해야 할 점에 대해 논하였다.

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A Method for Adaptive Hysteresis Current Control of PWM Inverter Using Neural Network (신경회로망을 이용한 PWM 인버터의 적응 히스테리시스 전류제어 기법)

  • 전태원;최명규
    • The Transactions of the Korean Institute of Power Electronics
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    • v.3 no.4
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    • pp.382-387
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    • 1998
  • The adaptive hysteresis band current control method using neural network is proposed to hold the switching frequency of PWM inverter constant at any operating points of ac motor. The adaptive hysteresis band equation is derived as the teaching signal of neural network. and then the structure and learning algorithm of the neural network a are suggested. The simulation results show that the switching frequency of PWM inverter is held constant at any operating conditions of ac motor and the proposed method has good transient performance of stator current.

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Comparison of Lipid Components in Wild and Cultured Bastard (천연 및 양식산 넙치의 지방질성분)

  • Oh, Kwang-Soo;Ro, Rack-Hyun;Kim, Jeong-Gyun;Lee, Eung-Ho
    • Korean Journal of Food Science and Technology
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    • v.20 no.6
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    • pp.878-882
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    • 1988
  • The lipid components of cultured bastard(Paralichthys olivaceus) were analyzed and compared with those of wild one and flounder(Pleuronichthys cornutus). Total lipid(TL) content of dorsal muscle in wild and cultured bastard, flounder was 2.0%, 1.6%, and 1.9%, respectively. Wild bastard and flounder were higher in neutral lipid(NL) and glycolipid(GL) contents, while lower in phospholipid(PL) content than those of cultured one. The NL was mainly consisted of triglyceride(70.7-72.6%), and PL was mainly occupied by phosphatidylcholine(53.6-58.3%), phosphatidyl-ethanolamine(25.9-29.5%). In fatty acid composition of TL, cultured bastard showed higher content in polyenes such as docosahexaenoic acid. and lower in monoenes such as palmitoleic, oleic acid than those of wild one. Flounder was higher in Percentage of arachidonic, eicosapentaenoic acid compard with bastard. The major fatty acids of these fishes were palmitic, docosahexaenoic, oleic, eicosapentaenoic and palmitoleic acid in order. These fatty acid composition of NL, GL and PL fractions were not significantly different among wild and cultured bastard, flounder.

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The Effects of Instruction and Stimulus Presentation Time in Attention Bias Modification Training on Social Anxiety Symptom Group (주의편향수정 훈련에서 지시문과 자극제시 시간의 효과: 사회불안증상 집단을 대상으로)

  • Kim, Seul-A;Hong, Chang-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.641-649
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    • 2020
  • This study was conducted to examine the effects of instruction (explicit, implicit) and stimulus presentation time (300 ms, 500 ms) in ABM training. According to the Social Avoidance and Distress Scale (SADS) and the attention bias score (ABS), 60 undergraduate students were selected. All participants' SADS scores were above 82 and their ABS score was greater than 0. The training group was explicit-300 ms training group (n=10), explicit-500 ms training group (n=10), implicit-300 ms training group (n=10) and implicit-500 ms training group (n=10). In the implicit instruction group, only information about procedure was included. In the explicit instruction group, additional information about training manipulation (the probe always presented at the location of the preceding neutral stimuli) was provided. The control group were placebo-300 ms control group(n=10) and placebo-500 ms control group(n=10). After 8 sessions of training, the effect was only found in instruction conditions. The explicit training group showed significantly decreased SADS after training. ABS changed significantly in all three conditions but the treatment effect was most effective in the explicit instruction condition. No significant effect was found in the stimulus presentation time. These results suggest that explicit instruction might promote the effect of ABM training compared to implicit instruction.

Attention Bias Toward Drug Cues in Female Methamphetamine Addicts (여성 메스암페타민 중독자의 약물 단서에 대한 주의편향)

  • Kim, Na-Yeon;Eum, Young-Ji;Kim, Kyo-Heon
    • Science of Emotion and Sensibility
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    • v.22 no.4
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    • pp.75-84
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    • 2019
  • Addicts pay more attention to addiction-related cues, such as substance or behavior. And increased attention to these cues is associated with craving. Methamphetamine is the most abused drug among domestic drug offenders, with continually increasing rates of recidivism. Of the total number of reported drug offenders in the last three years, 21.1 percent have been women. Even so, research on female drug offenders is inadequate, rendering policies and fundamental data for the development of psychotherapy programs insufficient. The present study intended to investigate whether female methamphetamine addicts displayed an attention bias towards drug cues. A dot probe task was conducted on 22 female methamphetamine addicts (addiction group) and 22 non-addicts (control group). The task allowed the correct response rates and correct reaction times of the participants to be calculated according to the positioning of the drug and neutral cues. The analysis results revealed that the control group displayed no difference in correct reaction rates and correct reaction times between the drug or neutral cues. While, the addiction group showed lower correct response rate and slower response time for drug cues in comparison to neutral cues. The results of this study are significant in that it identified the attention bias characteristics toward drug cues of female methamphetamine addicts who were disconnected from drugs.

Morphological Characteristics and Physiological Effects of Mulberry Leaves and Fruits with Wild Varieties (횡성군 일대에서 채취한 야생뽕의 형태학적 특성 및 오디의 효능)

  • 김현복;박광준;석영식;김선림;성규병;남학우;문재유
    • Journal of Sericultural and Entomological Science
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    • v.44 no.1
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    • pp.4-8
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    • 2002
  • We conducted this study to investigate the morphological characteristics and physiological effects of mulberry leaves and fruits with wild varieties. Morphologically sampling materials were showed Morus bombycis type and Morus alba type characteristics. Water contents of mulberry fruits were higher than that of mulberry leaves. Sugar degree of sampling materials was 5.1∼22.7 Brix %. The yield of 85% MeOH extract from freezing dried Mulberry Fruits was 60.2% and Hexane, BuOH and H$_2$O fraction from MeOH extract were 2.8%, 4.6%, 92.3% respectively. In the cholesterol-induced hyperlipidemia rats administered with subfraction of mulberry fruit extract, total cholesterol and serum triglyceride were decreased in the MeOH extract group and H$_2$O soluble fraction group. Also H$_2$O soluble fraction group decreased GPT, GOT and LDH level. Therefore, the above results suggested that mulberry fruit with wild varieties can help to maintain normal liver functions and to protect hyperlipidemia.