• Title/Summary/Keyword: Phase Variable

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A Generalized Predictive Self-Tuning Control Using Mean Horizon Control Method (Mean Horizon 제어방식을 사용한 일반화 예측 자기동조 제어)

  • Park, Juong-Il;Chung, Jong-Dae;Park, Keh-Kun
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.9
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    • pp.1039-1045
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    • 1988
  • In the original incremental generalized predictive control, the receding horizon predictive control is introduced as a control law. But in this paper, we propose a generalized predictive self-tuning control using full-valued incremental controls. The control law is a mean horizon predictive control. The effectiveness of this algorithm in a variable time delay or load disturbances environment is demonstrated by computer simulation. The controlled plant is a nonminimum phase system.

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A study on the Variable Elimination of the 0-th order Diffraction Using the Fourier Transform in the Digital Holography Microscope System

  • Choi, Kyu-Hwan;Kim, Sung-Kyu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1357-1360
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    • 2009
  • In this study, the 0-th order diffraction could be efficiently removed with the obtained data for one hologram using the numerical reconstruction method. This method has a reduced data acquisition and processing time compared with the existing method wherein the data for two or more phase holograms are obtained for regeneration, and efficiently eliminates the 0-th order diffraction.

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A Study on the Improvement of the IM Speed Control Characteristics with Load Torque Variation (부하 변동에 대한 유도 전동기의 속도 제어 특성에 관한 연구)

  • 강문호;김남정;유기윤;박귀태;민경일
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.7
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    • pp.1075-1083
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    • 1994
  • In this paper, a study on the improvement of the IM speed response against load torque variation is presented. A VSCS(Variable Structure Control System) is proposed which gives the desired robustness against load torque variation using a new kind of time-varing switching plane. In order to eliminate the reaching phase of the states from one switching plane to another during variation, the switching plane is varied continuously. To verify the high dynamic performance of the proposed VSCS, simulation and experimental results are presented.

Speed control induction motor (속도제어형 유도전동기)

  • 오상세;박창엽
    • 전기의세계
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    • v.17 no.1
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    • pp.6-10
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    • 1968
  • To control of the speed of induction Motor, a variable frequency power supply is needed. But this New type induction Motor Constitute stator and Rotor with New principle, its speed can be easily and widely Controlled by changing phase of the stator, and start at low current than rating without starter. Also, its no load current is same as shart current, and speed increase in proportion to current. On this points this induction Motor for speed control is different from induction Motor using Now.

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Paraffinoma induced bilateral preauricular cheek skin defects

  • Heo, Jae-Woo;Kim, Baek Kyu
    • Archives of Craniofacial Surgery
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    • v.19 no.3
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    • pp.227-230
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    • 2018
  • "Paraffinoma" is a well-recognized complication of paraffin oil injection into various body parts for an aesthetic purpose. After a variable latency phase, paraffinoma can present as a wide range of clinical symptoms. This paper is a case report of surgical excision of the paraffinoma and subsequent reconstruction of the associated skin defect on bilateral preauricular cheeks, manifesting 50 years after a primary injection.

Frequency relativity of soil resistivity (대지저항률의 주파수 의존성)

  • 이복희;조성철;엄주홍
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2003.11a
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    • pp.373-376
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    • 2003
  • A new method measuring soil resistivity in frequency range of 5-500[KHz] using variable frequency inverter was presented, and soil resistivity was analysed by resistive and reactive components on the basis of magnitude and phase of measured ground impedance. The test lead arrangement was proposed to reduce the inductive coupling in test circuit for measuring the soil resistivity. The frequency dependence of soil resistivity was mainly caused by the inductive current flowing through grounding conductors over the frequency of 70[KHz].

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Design of Optimal Controller Using Discrete Sliding Mode

  • Kim Min-Chan;Ahn Ho-Kyun;Kwak Gun-Pyong;Nam Jing-Rak
    • Journal of information and communication convergence engineering
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    • v.2 no.3
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    • pp.198-201
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    • 2004
  • In this paper, the discrete optimal control is made to have the robust property of Sliding mode controller. A augmented system with a virtual state is constructed for this objective and noble sliding surface is constructed based on this system. The sliding surface is the same as the optimal control trajectory in the original system. The states follow the optimal trajectory even if there exist uncertainties. The reaching phase problem of sliding mode control is disappear in this method.

Phase Stability and Electronic Properties of $Bi_2BaLnCuO_{6+δ}$ Cuprates with Structure 2201 Type

  • V. E. Fedorov;N. G. Naumov;P. P. Samoilov;N. F. Zakharchuk;N. I. Matskevich;백우현
    • Bulletin of the Korean Chemical Society
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    • v.16 no.6
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    • pp.484-489
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    • 1995
  • The synthesis of new bismuth-barium containing members of layered cuprates with 2201 type structure was reported. By solution calorimetry the formation enthalpies for Bi2MLaCuO6.5 (M=Ba, Ba0.5Sr0.5, Sr) were obtained. Crucial influence of partial oxygen pressure and size of lanthanoid on stability of layered cuprates was shown. Electronic states of variable valence atoms were studied by voltammetry of solids.

Experimental Study of the Phase Equilibria for $CO_2$ in Liquified Natural Gas Components at 77-219K

  • Yun, Sang-Kook
    • International Journal of Air-Conditioning and Refrigeration
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    • v.11 no.2
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    • pp.61-66
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    • 2003
  • In order to prevent roll-over and a rapid boil-off of LNG in tanks, the phase equilibria of carbon dioxide in liquefied natural gas components as binary mixtures at cryogenic temperatures have been experimentally measured using Fourier transform infrared spectroscopy in conjunction with a specially designed variable pressure/temperature cryostat cell (pathlength 2 mm; pressures up to 30 bar). Solid carbon dioxide has been found to be comparatively soluble in liquid nitrogen (3.25$\times$${10}^{-6}$ mole fraction), liquid methane (1.04$\times$${10}^{-4}$ mole fraction), liquid ethane (3.1$\times$${10}^{-2}$ mole fraction) and liquid propane (6.11$\times$${10}^{-2}$ mole fraction) at their normal boiling temperatures. The solubilities of carbon dioxide in various cryogens, which increased with increasing temperature, are much lower than those obtained by others using gas chromatography. The differences are attributed to infrared spectroscopy selectively measuring dissolved solute in situ whereas gas chromatography measures microscopic particulate solid in addition to dissolved solute.

Application of thermodynamics to chemical vapor deposition (화학증착에서 열역학의 응용)

  • Latifa Gueroudji
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.1
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    • pp.80-83
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    • 1999
  • Processing of thin films by chemical vapor deposition(CVD) is accompanied by chemical reactions, in which the rigorous kinetic analysis is difficult to achieve. In these conditions, thermodynamic calculation leads to better understanding of the CVD process and helps to optimise the experimental parameters to obtain a desired product. A CVD phase diagram has been used as guide lines for the process. By determining the effect of each process variable on the driving force for deposition, the thermodynamic limit of the substrate temperature for a diamond deposition is calculated in the C-H system by assuming that the limit is defined by the CVD diamond phase diagram. The addition of iso-supersaturation ratio lines to the CVD phase diagram in the Si-Cl-H system provides additional information about the effects of CVD porcess variables.

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