• Title/Summary/Keyword: KRISS

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Harmonic Waveforms Analysis and Efficiency Measurement of Inverter for driving Induction Motors (유도형 모터 구동용 인버터의 고조파 파형 분석과 효율 측정)

  • Jang, Seok-Myeong;Jeong, Sang-Sub;Park, Young-Tae
    • Proceedings of the KIEE Conference
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    • 1997.07a
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    • pp.282-284
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    • 1997
  • The harmonics are injurious on the operation of the motor, electric instruments etc. In this paper, it is certified the capability of the electric measuring devices at the input/output of inverter. And it is measured the harmonics of the voltage and current waveforms. Also, this paper presents the efficiency of the inverter's power conversion by measuring the fundamental and total power at the input, DC bus and output.

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Reference DC/AC Power comparator on the basis of precision thermal converters (정밀 열전형변환기를 사용한 기준직교류전력비교기)

  • Park, Young-Tae;Jang, Seok-Myeong
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.676-678
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    • 1995
  • The Paper describes a dc/nc power comparator for measurement of power. Based on a thermal principle, the instrument performs ac-dc transfer and absolute power and energy measurements in the range of currents from 0 to 5 A, voltages from 60 to 240 V, power factors from 0 to 1 and frequencies from 50 to 1000 Hz. The ac-dc transfer accuracy is better than 20 ppm at unity power factor and better than 50 ppm at 0.5 power factor.

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Thin film growth by charged clusters

  • Hwang, N.M.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.09a
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    • pp.33-33
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    • 1998
  • Invisible charged clusters are suggested to form in the gas phase and to become the growth unit in the thin film process. Similar suggestion had been made by Glasner el al. in the crystal growth of KBr and KCL in the solution where the lead ions were added. The charged cluster model, which was suggested in the diamond CVD process by our group, will be extended to the other thin film processes. It will be shown based on both the theoretical analysis and the experimental evidences that the charged clusters are formed in the gas phase and become the growth unit of the crystal in the thin film process.

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다양한 통신위성에 따른 KRISS와 NICT 시각비교

  • Han, Ji-Ae;Yang, Seong-Hun;Lee, Yeong-Gyu;Lee, Seung-U;Lee, Chang-Bok
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.490-492
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    • 2006
  • 본 논문에서는 현재 KRISS(한국표준과학연구원)에 구축 된 JCSAT-1B 위성과 PAS-8 위성 그리고 PAS-4 위성을 이용하여 KRISS와 NICT(일본의 정보통신연구기관)간의 양방향 시각비교를 통하여 그들의 안정도를 비교분석하고 향후 JCSAT-1B 위성의 백업시스템으로써 PAS-4 위성과 PAS-8 위성의 활용성을 검토하였다.

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Robust Peak-to-peak Control of the Linear System (선형 시스템의 강인 피크 제어)

  • Ma, Sam-Sun;Hong, Seung-Soo;Kim, Jin-Hoon
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.1973-1975
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    • 2001
  • In this paper, we consider the problem of robust peak-to-peak controller design of linear system. The goal is to design a controller which minimizes the maximum peak value of the measured output subjects to the peak bounded disturbance. The control is obtained by checking the feasibility of the derived matrix inequalities. Finally, we shows the usefulness of our result comparing to $H_{\infty}$ and $H_{2}$ control by an example.

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Characteristics on the Harmonic Sensitivity of Induction Watthour Meter (유도형 적산전력량계의 고조파 민감도 특성)

  • Jang, Seok-Myeong;Lee, Sung-Ho;Park, Young-Tae
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.31-33
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    • 1998
  • The sensitivity of induction watthour meter was reviewed by characteristic tests under the effects of each input harmonics and the variation of power factor of inverter input/output terminal. This paper presents experimental data on the characteristics of induction watthour meter under the effect of harmonics.

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Capability of force standards at KRISS (한국의 힘표준 능력)

  • 강대임;박연규;김종호;김민석
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.9
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    • pp.7-11
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    • 2004
  • 일상생활과 산업현장에서 측정되는 힘의 범위를 정리해 보면 Fig. 1 과 같다. 힘의 SI 단위인 1뉴턴(N : 단위 질량 1 kg에 대해 1$m/s^2$ 의 가속도를 생기게 하는 힘의 크기임 정성적으로는 사과 반쪽을 손에 들고 있을 때 느끼는 중력의 크기가 약 1 N임)을 기준으로 크게는 수십 MN($10^{6}$ N) 크기의 우주선에서 발생하는 추진력에서부터 작게는 수 PN($10^{-12}$ N) 크기의 원자들 사이의 결합력까지 그 범위가 매우 광범위하다.