• 제목/요약/키워드: line sources

검색결과 621건 처리시간 0.028초

전원선 전도잡음 분리기 설계에 관한 연구 (A Study on the Design of Conducted Noise Separator for Power Line Noise)

  • 권준혁;이응주
    • 한국전자파학회논문지
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    • 제9권4호
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    • pp.552-559
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    • 1998
  • Conducted noise in power line contains both the common mode(CM) and differential mode(DM) noise. These two modes of noise are caused by different noise sources and paths. Therefore, CM/DM noise must be deal with individually in EMI filter. In this paper the technique to separate power line noise is presented, which can be used to measure both the CM and the DM noise from total generated noise. Also, noise-separator is designed and experimental results showed 30 dB above of separation performance in 10 kHz~10 MHz.

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국내 전동차 스퀼소음에 관한 연구 (A Study on the Squeal Noise for Domestic EMU)

  • 문경호;김재철;유원희;서정원
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(I)
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    • pp.66-71
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    • 2002
  • Squeal noise is generated by railway vehicles transversing tight curves. This squeal has always been noticed as one of the most disturbing noise sources of railway systems. At present we cannot predicted squeal noise that is influenced by a large number of dependent parameters. In this study, we performed structural analysis to find out the frequency of the wheel and also measured squeal noise at Seoul subway line 1, line 2, line 4 for domestic EMU(Electrical Multiple Unit).

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견인전동기용 고정자 코일의 off-line 부분방전 진단을 위한 NN의 적용 (An application of NN on off-line PD diagnosis to stator coil of Traction Motor)

  • 전용식;박성희;장동욱;박현준;강성화;임기조
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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    • pp.653-657
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    • 2004
  • In this study, PD(partial discharge) signals which occurrs at stator coil of traction Motor are acquired. these data are used for classifying the PD sources. W(Neural Network) has recently applied to classify the PB pattern. The PD data are used for the learning process to classify PD sources. The PD data come from normal specimen and defective specimens such as internal void discharges, slot discharges and surface discharges. PD distribution parameters are calculated from a set of the data, which is used to realize diagnostic algorithm. NN which applies distribution parameters is useful to classify the PD patterns of defective sources generating in stator coil of traction motor.

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Statistical Studies Based on SiO and $H_2O$ Maser Survey toward Evolved Stars

  • 김재헌;조세형;김상준
    • 천문학회보
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    • 제37권2호
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    • pp.237.1-237.1
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    • 2012
  • We report extensive statistical analyses based on the simultaneous observational results of SiO and $H_2O$ masers toward 166 known both SiO and $H_2O$ maser sources (Kim et al. 2010), 83 known SiO maser sources (Cho & Kim 2012 submitted), and 152 known $H_2O$ maser sources (Kim et al. 2012 in preparation). We investigate mutual relations between SiO and $H_2O$ maser properties (peak and total flux density ratios, full line width ratios, and velocity structures etc.) according to stellar pulsation phases and type of evolved stars. These statistical results are compared with monitoring observational results of some individual stars. In addition, a relation between the full line width of SiO/$H_2O$ masers and stellar mass loss rates is examined. For 401 observed stars, we also investigate characteristics of SiO and $H_2O$ maser properties related with evolutionary stages in the IRAS two-color diagram.

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한국 여자 수영복 디자인의 변천(I) (A Study on the Korean Women's Swimwear Design(I))

  • 김혜경;조은정;최형민
    • 한국의류산업학회지
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    • 제6권5호
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    • pp.558-564
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    • 2004
  • The purpose of this study was to examine the design characteristics of women's swimwear from 1955 to 1969 in Korea using documentary research sources. Both visual and linguistic elements found in the illustrations and advertisements that appeared in periodicals from 1955 to 1969 were used as primary sources. The primary sources were 아리랑, 여상, 여성계, 여성동아, 여원, 주부생활. The methods of content analysis and frequency seriation were combined to analyze the data obtained from the primary sources. Seriational analysis of the data were performed by ordering the frequency chronologically for the entire fifteen-year period. As the result of the study, it was found that the design of the swimwear during this period changed consistently in terms of swimwear type, shape of thigh line, textile design and decorative details. The degree of skin exposure was also continuously increased in different body parts.

NIR spectroscopy of three class I young stellar objects using IGRINS

  • Sharma, Neha;Lee, Joeng-Eun;Park, Sunkyung;Lee, Soekho;Yoon, Sung-Yong
    • 천문학회보
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    • 제44권1호
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    • pp.66.3-66.3
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    • 2019
  • We present near-infrared spectroscopic results for three nearby class I sources, IRAS 03445+3242, IRAS 04239+2436 and ESO $H{\alpha}$ 279a. We detected many molecular and atomic line emissions, e.g., $H_2$, [Fe II], Hydrogen Bracket series recombination, Ca I, Na I & CO overtone band, from these sources using the high-resolution Immersion GRating INfrared Spectrometer (IGRINS; R~45,000). Previous studies showed that all the three sources posses actively accreting Keplerian disks. We performed spectral analysis to understand the origin of Hydrogen Bracket series recombination lines. We also estimated the accretion properties and mass loss rates of circumstellar disks for all the three sources.

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Use of Mobile Devices in the Performance of Group Decision-Making under Contextual Pressure

  • Kwon, Oh-Byung;Kim, Tae-Kyung;Kim, Choong-Rhyun
    • Journal of Information Processing Systems
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    • 제3권2호
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    • pp.64-72
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    • 2007
  • Mobile technology appears promising as a method to promote group performance in circumstances dependent on time, but not member proximity. However, the success of mobile technology in group decision-making situations has not yet been proven. This paper aims to see how mobile technology affects the performance of group decision-making tasks that should be resolved urgently and/or sources of idea are disconnected with on-line network. Laboratory experiment was used to investigate the effects of mobile factors on group decision-making. The results from the experiment supported the proposition that pressures of time and location play a significant role in the assessment of group decision performance measures. We found that the adoption of mobile technology to group decision-making procedures might be competitive when group decision-making tasks are urgent and sources of idea are disconnected with on-line network, even though mobile technology is not a panacea on which to depend when designing group decision-making.

KSTAR 중성빔 입사(NBI) 장치 배기계통 설계 (Design of the vacuum pumping system for the KSTAR NBI device)

  • 오병훈;인상렬;조용섭;김계령;최병호
    • 한국진공학회지
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    • 제8권4B호
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    • pp.548-555
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    • 1999
  • The NBI (Neutral BGeam Injection) System for the Korea Superconducting Tokamak Advanced Research (KSTAR) is composed of ion sources, neutralizers, bending magnets, ion dumps, and calorimeter. The vacuum chamber, in which all of the beam line components are enclosed, is composed of differential pumping system for the effective transfer of the neutral beams. The needed pumping speeds of each of the divided vacuum chamber and the optimized gas flow rate ot the neutralizer were calculated with the help of the particle balance equations. The minimum gas flow rate to the ion sources for producing needed beam current (120kV, 65A, 78MW), the pressure distributions in the vacuum chamber for minimizing re-ionization loss, and the beam loss rate on the beam line components were used as the input in the calculation. Also the scenario for short pulse operation was determined by analysing the time dependent equations. It showed that beam extraction during less than 0.5 sec could be made only with TMP.

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HANbit ACE64 ATM 교환기 시스템의 Twinax 케이블 모델링 (Twinax Cable Modeling for Use in HANbit ACE64 ATM Switching Systems)

  • 남상식;박종대
    • 한국통신학회논문지
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    • 제24권12A호
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    • pp.1985-1991
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    • 1999
  • 본 논문은 HANbit ACE64 ATM 교환기 시스템의 데이터 경로인 IMI(Inter Module Path)에 사용되는 고속 전송선로인 Twinax 케이블을 two-port lumped Spice-network 모델로 구현하기 위해 lumped 네트워크 요소와 수학적 함수를 사용하여 개발하였다. 사용된 요소들은 저항성분과 주파수의존 전압제어 소스로 구성되어 있고 Hspice 수학적 함수인 FREQ, DELAY, POLY를 사용하여 구현하였다. 구현된 모델을 사용하여 케이블 길이와 종류에 따른 각종 노이즈 분석을 실시하여 그 특성을 비교 분석하였다.

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미생물 배양액으로부터 항암제의 예비선별을 위한 cccDNA Breakage 활성검정과 Assay Sulforhodamine B 활성검정의 이용 (Use of cccDNA Breakage Assay and Sulforhodamine B Assay for the Prescreening of Antitumor Agents from Microbial Sources)

  • 이상한;이동선;김종국;홍순덕
    • 생명과학회지
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    • 제8권1호
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    • pp.67-71
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    • 1998
  • 다량의 시료를 빠르게, 적은 격비로, 간다히 검색할수 있는 예비선별법을 찾던중, ccDNA와 sulforhodamine B를 각각 사용한 미생물배양액내의 신규항암후보물질의 탐색을 시도하였다. cccDNA법으로는 3.3%가 positive 반응을 나태내었으며, SRB assat에서는 A549와 SK-OV-3에 활성을 나타내는 4개의 발효여액을 확인한수 있었다.

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