• Title/Summary/Keyword: Domain switching

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Simultaneous Switching Noise Reduction Technique in Multi-Layer Boards using Conductive Dielectric Substrate (전도성 유전기판을 이용한 다층기판에서의 Simultaneous Switching Noise 감소 기법)

  • 김성진;전철규;이해영
    • Journal of the Microelectronics and Packaging Society
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    • v.6 no.4
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    • pp.9-14
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    • 1999
  • In this paper, we proposed a simultaneous switching noise (SSN) reduction technique in multi-layer boards (MLB) for high-speed digital applications and analyzed it using the Finite Difference Time Domain (FDTD) method. The new structure using conductive dielectric substrates is effective for the reduction of SSN couplings and resonances. The uniform insertion of the conducive layer reduced the SSN coupling and resonance by 85% and the partial insertion only around the edges reduced by 55% respectively.

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A controller design method of switching regulator satisfying time-domain specifications (시간 영역에서의 성능 사양 만족을 위한 스위칭 직류 변환기의 제어기 설계)

  • 고정호;권봉환;윤명중
    • 제어로봇시스템학회:학술대회논문집
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    • 1986.10a
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    • pp.576-579
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    • 1986
  • In this paper, a design method of an optimal output PIM(Proportional-Integral-Measurable) controller is presented so that the closed-loop output response of the switching regulator closely match to that of ideal model system satisfying the time domain specifications. The computer simulation for a design example is given to show the usefulness of the proposed technique.

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Eigenvalue Sensitivity Analysis of Discrete Power Systems Including Generator Controllers and TCSC (발전기 제어장치와 TCSC를 포함하는 이산 전력시스템의 고유치 감도해석)

  • Kim, Deok-Young
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.12
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    • pp.193-200
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    • 2010
  • In this paper, the eigenvalue sensitivity analysis is calculated in the power system which is including both generator controllers such as Exciter, PSS and thyristor controlled FACTS devices in transmission lines such as TCSC. Exciter and PSS are continuously operating controllers but TCSC has a switching device which operates non-continuously. To analyze both continuous and non-continuous operating equipments, the RCF method one of the numerical analysis method in discrete time domain is applied using discrete models of the power system. Also the eigenvalue sensitivity calculation algorithm using state transition equations in discrete time domain is devised and applied to a sampled system. As a result of simulation, the eigenvalue sensitivity coefficients calculated using discrete system models in discrete time domain are changed periodically and showed different values compared to those of continuous system model in time domain by the effect of periodic switching operations of TCSC.

Low delay window switching modified discrete cosine transform for speech and audio coder (음성 및 오디오 부호화기를 위한 저지연 윈도우 스위칭 modified discrete cosine transform)

  • Kim, Young-Joon;Lee, In-Sung
    • The Journal of the Acoustical Society of Korea
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    • v.37 no.2
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    • pp.110-117
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    • 2018
  • In this paper, we propose a low delay window switching MDCT (Modified Discrete Cosine Transform) method for speech/audio coder. The window switching algorithm is used to reduce the degradation of sound quality in non-stationary trasient duration and to reduce the algorithm delay by using the low delay TDAC (Time Domain Aliasing Cancellation). While the conventional window switching algorithms uses overlap-add with different lengths, the proposed method uses the fixed overlap add length. It results the reduction of algorithm delay by half and 1 bit reduction in frame indication information by using 2 window types. We apply the proposed algorithm to G.729.1 based on MDCT in order to evaluate the performance. The propose method shows the reduction of algorithm delay by half while speech quality of the proposed method maintains same as the conventional method.

Magnetization Reversal and Magnetic Switching Volume in Electrodeposited CoPt Magnetic Films with Different Thickness (전기도금법으로 제작한 두께가 다른 CoPt 자성막의 자화역전과 자기역전 부피)

  • Kim, Hyeon-Soo;Jeong, Soon-Young;Lee, Chang-Hyeong;Suh, Su-Jeong
    • Journal of the Korean Magnetics Society
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    • v.21 no.6
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    • pp.193-197
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    • 2011
  • The thickness dependence of the magnetic switching volumes in electrodeposited CoPt films was investigated from the magnetization reversal and the magnetic interaction behavior. As the sample thickness is increased, the field difference between the wall pinning field ($H_{DW}$) and the nucleation field ($H_N$) as well as the absolute value of ${\Delta}$area are increased. Therefore, the decrement tendency of the switching diameter with increasing sample thickness can be well explained by the domain wall motion controlled by the domain wall pinning and the strength of dipolar interaction.

$H_{\infty}$ Switching PSS and Load Variation Analysis ($H_{\infty}$ 스위칭 제어 비선형 전력계통안정화장치(NPSS) 설계 및 부하변동 분석)

  • Lee, Sang-Seung
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.229-231
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    • 2005
  • This paper presents the nonlinear $H_{\infty}$ switching power system stabilizer (PSS) based on Lie group and Lie transformation theory. The proposed controller combines the $H_{\infty}$ switching controller and Lie theory. The proposed power system stabilizer (PSS) is used to improve the transient stability in the time-domain and to solve the problem associated with the inaccessible state variables by measuring only the angular velocity. In the simulation study, the different load conditions, fault periods, and fault locations are considered. The nonlinear time-domain simulation showed that the proposed controller was effective restoring transient stability in a one-machine infinite-bus power system.

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Electro-Optic Characteristics of the Dual Domain Fringe-Field Switching(FFS) Mode using the Liquid Crystal with Negative Dielectric Anisotropy (유전율 이방성이 음인 액정을 이용한 이중 도메인 FFS 모드의 전기광학 특성)

  • 김향율;고재완;노정동;서대식;이승희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.8
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    • pp.720-725
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    • 2002
  • The fringe-field switching (FFS) mode was known to exhibit both a wide viewing angle and high transmittance, especially when using the liquid crystal (LC) with negative dielectric anisotropy. In the device, the LC director rotates almost in-plane. However, in the bright state the device shows bluish and yellowish color along parallel and perpendicular to the LC director at off-normal directions since the LC director rotates only in one direction. Such a problem was greatly improved using a wedge shape of only pixel electrodes. In this way two different field directions exist in a pixel, enabling the LC director to rotate in two opposite directions. Consequently, owing to dual domain effect when using the LC with negative dielectric anisotropy, the viewing angle characteristics are greatly improved.

Analysis of a Crack in Ferroelectric Ceramics Subjected to Electric Fields (전기장을 받는 강유전체 세라믹내의 균열 해석)

  • 범현규;김인옥
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.6
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    • pp.138-144
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    • 2003
  • A crack in a ferroelectric ceramic subjected to an electric field is analyzed. The boundary of the electrical saturation zone is estimated based on the finite-width saturation zone model, which is analogous to a finite-width Dugdale zone model for mode III. It is shown that the shape and size of the switching zone depends strongly on the boundary of the electrical saturation zone and the ratio of the coercive electric field to the yield electric field. The crack tip stress intensity factor under small scale conditions is evaluated by employing the model of electric nonlinear domain switching. It is found that fracture toughness of the ferroelectric material may be increased or decreased depending on the material property of electrical nonlinearity.

Conducting Crack Growth Behavior in Ferroelectrics Subjected to Electric Fields (전기장을 받는 강유전체 내의 전도균열 성장거동)

  • 정경문;박재연;범현규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.820-823
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    • 2002
  • The asymptotic problem of a semi-infinite conducting crack parallel to the poling direction in ferroelectric ceramics subjected to electric fields is analyzed. The main mechanism for the conducting crack growth behavior is thought to be ferroelectric domain switching leading to the development of a process zone around the crack. The shape and size of the switching zone is shown to depend strongly on the relative magnitude on the ratio of the coercive electric field to the yield electric field. It is shown that the crack growth can be either enhanced or retarded depending on the ratio of the coercive electric field to yield electric field.

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A Performance Evaluation on Optical Burst Switched Networks and Wavelength Routed Networks (광 버스트 스위칭 네트워크와 파장 라우팅 네트워크의 성능 비교)

  • 유명식;정연미;홍현하
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.5B
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    • pp.404-413
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    • 2003
  • Optical Internet consists of IP domain and optical (WDM) domain, where the wavelength routing (WR) and optical burst switching (OBS) are the promising switching technologies in the optical domain. In this paper, we perform the simulations on the WR network and the OBS network, and compare their performances. It is verified from our simulations that the OBS network performs better than the WR network when the same network resources are given.