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Static VAR Compensator Using 3-Phase PWM Converter(II) (3상 PWM 콘버어터에 의한 정지형 무효전력 보상장치의 동작특성( II ))

  • Kwon, Soon-Jae;Whang, Yong-Moon;Kim, Kwang-Tae;Kim, Cheul-U
    • Proceedings of the KIEE Conference
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    • 1988.11a
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    • pp.287-289
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    • 1988
  • A reactive power compensator whiych employs a 3-phase voltage source PWM converter is presented and ana lysed in this study. In this study, instantaneous reactive power compensator by the theort of instantaneous real and imaginary power are theoretically studied how to compensate reactive power occured by fundamental and harmonic reactive current. And we showed the compensation characteristic as well as the capacity of condenser.

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The Application of Boiler Digital Control System 3D MMI Using Virtual Real (보일러 분산제어 시스템 3차원 MMI 구현)

  • Oh, Young-Il;Kim, Eung-Seok
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.880-882
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    • 1999
  • Virtual Reality is a set of computer technologies which, when combined, provide an interface to a computer-generated world, and in particular, provide such a convincing interface that the user believes he is actually in a three dimensional computer-generated world. This computer generated world may be a model of a real-world object, such as a house; it might be an world that does not exist in a real sense but is understood by humans, such as a chemical molecule or a representation of a set of data; or it might be in a completely imaginary science fiction world. this paper describes the application of boiler digital control system MMI for power plant using virtual reality

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Measurement of Spatial Coherence Function of laser beam by using a Sagnac Interferometer (샤냑간섭계를 이용한 레이져빔의 Spatial Coherence Function 측정)

  • Lee, Chang-Hyouck;Kang, Yoon-Shik;Sung, Yu-Gene;Noh, Jae-Woo
    • Proceedings of the Optical Society of Korea Conference
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    • 2007.07a
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    • pp.111-112
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    • 2007
  • The spatial coherence function of laser beam was measured by using a Sagnac interferometer and self referencing technique. For laser beam passing through a narrow slit, absolute value of measured spatial coherence function becomes more symmetric as the slit size is reduced. For diverging beams, the spatial coherence function shows fast oscillations in its real and imaginary parts. We explain this by using a Gaussian Schell-model. One can use this measurement method to study and characterize the property of light field coming out of small sample.

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Static VAR Compensator Using 3 Phase PWM converter (3상 PWM 콘버어터에 의한 정지형 무효전력 보상장치의 동작특성)

  • Kim, Cheul-U;Kim, Kwang-Tae;Kwon, Soon-Jae;Hong, Soon-Il
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.137-139
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    • 1988
  • A reactive power compensator whitch employs a three phase voltage source PWM converter is presented and analysed in this study. In this study, instantaneous reactive power compensator by the theory of instantaneous real and imaginary power are theoretically studied how to compensate reactive power occured by fundamental and harmonic reactive current. And we showed the compensation characteristics by comparing the experimental results with those of computer simulation.

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The Diophantine Equation ax6 + by3 + cz2 = 0 in Gaussian Integers

  • IZADI, FARZALI;KHOSHNAM, FOAD
    • Kyungpook Mathematical Journal
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    • v.55 no.3
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    • pp.587-595
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    • 2015
  • In this article, we will examine the Diophantine equation $ax^6+by^3+cz^2=0$, for arbitrary rational integers a, b, and c in Gaussian integers and find all the solutions of this equation for many different values of a, b, and c. Moreover, two equations of the type $x^6{\pm}iy^3+z^2=0$, and $x^6+y^3{\pm}wz^2=0$ are also discussed, where i is the imaginary unit and w is a third root of unity.

Analysis of the Fear Inventory by Preschoolers' Sex, Age, and Degree of Emotional and Behavioral Problems (유아의 성, 연령, 정서행동문제 수준에 따른 유아기 두려움 목록 분석)

  • Koo, Mee-Hyang
    • Korean Journal of Child Studies
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    • v.30 no.3
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    • pp.55-69
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    • 2009
  • The purpose of this study was to describe preschoolers' perceptions of fear from their own perspective. Qualitative data from 213 preschoolers 4 to 6 years of age were obtained by semi-structured interviews. The fear inventory was analyzed by content analysis and frequency. The most common fears of preschoolers in this study were fear of ferocious animals and imaginary figures, such as tigers, lions, snakes, spirits and ghosts. Fear of ghosts was the primary fear of both boys and girls. Results showed that most fears were caused by disgust-related visual images. Worry about injury and pain was another common pathway to fear. At-risk preschoolers scored significantly higher than normal preschoolers on fears of criticism and getting an injection.

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Computation of distortion power using complex THD in harmonic distortion involved (THD의 복소 성분을 이용한 고조파 왜곡 환경에서의 전력량 계산)

  • Choi, Joung-Ug;Jang, Gil-Soo;Kwon, Sae-Hyuk;Lee, Han-Min;Kim, B.J.
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.202-204
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    • 2003
  • This paper introduces a new algorithm to calculate distortion power using complx THD(Total Harmonic Distortion) index. The proposed algorithm involves FFT(Fast Fourier Transform) to compute real and imaginary THDs of voltage and current. Case studies are presented to show the availability of the proposed method.

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Thermal characteristics variation of PDP in compliance with dielectric loss

  • Lee, Tae-Ho;Jung, Jae-Chul;Lee, Sang-Kuk;Kim, Joong-Kyun;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.265-268
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    • 2009
  • The discharge condition of Plasma display panel(PDP) changes as the display time increases. Imaginary part of permittivity of dielectric material which is related to dielectric loss has been often neglected because of relatively small value compare to that of the real part. The thermal characteristics of PDPs with two different dielectrics has been studied and compared.

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ON THE INFINITE PRODUCTS DERIVED FROM THETA SERIES I

  • Kim, Dae-Yeoul;Koo, Ja-Kyung
    • Journal of the Korean Mathematical Society
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    • v.44 no.1
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    • pp.55-107
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    • 2007
  • Let k be an imaginary quadratic field, h the complex upper half plane, and let $\tau{\in}h{\cap}k,\;q=e^{{\pi}i\tau}$. In this article, we obtain algebraic numbers from the 130 identities of Rogers-Ramanujan continued fractions investigated in [28] and [29] by using Berndt's idea ([3]). Using this, we get special transcendental numbers. For example, $\frac{q^{1/8}}{1}+\frac{-q}{1+q}+\frac{-q^2}{1+q^2}+\cdots$ ([1]) is transcendental.

An Accurate Small Signal Modeling of Cylindrical/Surrounded Gate MOSFET for High Frequency Applications

  • Ghosh, Pujarini;Haldar, Subhasis;Gupta, R.S.;Gupta, Mridula
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.4
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    • pp.377-387
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    • 2012
  • An intrinsic small signal equivalent circuit model of Cylindrical/Surrounded gate MOSFET is proposed. Admittance parameters of the device are extracted from circuit analysis and intrinsic circuit elements are presented in terms of real and imaginary parts of the admittance parameters. S parameters are then evaluated and justified with the simulated data extracted from 3D device simulation.