• Title/Summary/Keyword: 천이 파라미터

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Novel Design with Decreasing Conduction Loss in Auxiliary Switch for ZCT PWM Boost Converter (펄스 폭 변조-영전류 천이 승압형 컨버터에서 보조 스위치의 도통 손실을 줄이기 위한 공진 파라미터 설계)

  • Hwang, Ji-Hoon;Soh, Jae-Hwan;Kim, Rae-Young
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.157-158
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    • 2015
  • 본 논문 에서는 펄스폭 변조 영전류 천이 (PWM-ZCT) 승압형 컨버터에서 보조 회로로 흐르는 전류로 인한 도통 손실을 최소화 할 수 있는 공진 파라미터 최적화 방안을 제시한다. 제안된 해석을 통한 소프트 스위칭 기술 적용 시 추가적으로 발생한 보조 회로의 도통 손실을 최소화할 수 있다. 시뮬레이션 결과를 통하여 제안된 해석의 타당성을 입증 하였다.

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Noise Reduction Method for Image Using Transition-Parameter of Cellular Automata (셀룰러 오토마타의 천이 파라미터를 이용한 영상의 잡음제거 방법)

  • Kim, Tai-Suk;Lee, Seok-Ki;Kwon, Soon-Kak;Kwon, Oh-Jun
    • Journal of Korea Multimedia Society
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    • v.13 no.9
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    • pp.1329-1336
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    • 2010
  • Cellular Automata is a discrete dynamical system which natural phenomena may be specified completely in terms of local relation, can increase and decrease the difference of luminance locally according to transition rule by keeping the characteristic of target image. In this paper, we propose a noise reduction method by keeping the characteristic using transition rule of Cellular Automata, also we propose methods of effective transition rule, the selection of parameters, the selection of number of neighborhood pixels. For uniform distribution noise, Gaussian noise, impulse noise, we do an experiment on adaptive state using different mathematical operations and compare its results. It was confirmed that the proposed transition rule is based on fast convergence speed and has stabile results.

Online Cursive Handwriting Character Recognition Using a Bitmap Parameter (비트맵 파라미터를 이용한 온라인 필기체 문자인식)

  • 석수영;김민정;정호열;정현열
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.421-424
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    • 2001
  • 개별적인 인식기를 하나의 단일 인식 시스템으로 구성하여 음성과 문자를 인식할 수 있는 공용인식시스템의 성능향상을 위해 온라인 필기에서 전역적인 정보를 추출할 수 있는 비트맵 파라미터 추출 방법을 제안하였다. 제안된 방식에서는 고속의 파라미터 추출을 위해 보간법을 이용한 재샘플링 과정 대신에 새로운 시간열을 구성하는 방식을 이용한다. 제안한 비트맵 파라미터를 본 연구실에서 개발한 음성/문자 공용인식 시스템에 적용하기 위하여 67개의 자소를 5상태 10천이 CHMM(Continuous Hidden Markov Model)모델로 구성한 다음 인식알고리즘으로서는 상태단위로 지속 시간 정보를 제어하는 OnePassDP법을 이용하였다. 실험결과, 제안한 방법을 이용한 경우, 자소인식률은 61.3%에서 85.3%로 24%의 인식률 향상을 가져왔으며, 글자인식률은 64.3%에서 82.2%로 17.9%의 인식률 향상을 가져와 제안한 방법의 유효성을 확인할 수 있었다.

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A Built-in Self-Test of Static Parameters for Analog-to-Digital Converters (아날로그-디지털 변환기의 정적 파라미터 테스트를 위한 내장 자체 테스트 방법)

  • Kim, In-Cheol;Jang, Jae-Won;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.49 no.5
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    • pp.30-36
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    • 2012
  • A new BIST(Built-In Self-Test) scheme to test ADC(Analog-to-Digital Converter) with a transition detector is proposed. The proposed BIST is able to replaces histogram method, the most popular approach in static testing of ADC. With a ramp signal as an input test stimulus, the proposed BIST calculates ADC's static parameters such as offset, gain, INL(Integral Non-Linearity) and DNL(Differential Non-Linearity). The three detectors in the proposed BIST can deal with a transient zone problem, a phenomenon due to random noise in real test environments and are cost efficient at various acceptable ranges determined as a test spec. The simulation results validate that our method performs accurate static test and show the reduction of the hardware overhead.

Microstrip patch antenna using 3 dimensional microstrip transition (3차원 천이를 이용한 마이크로스트립 패치 안테나)

  • 박동국;최형동
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.4
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    • pp.817-821
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    • 2001
  • In this paper, we design a microstrip patch antenna using 3-dimensional microstrip transition with the VSWR 1.3 over the PCS band (1.75 -1.87 GHz). We study experimentally the effect of the antenna parameters on antenna input impedance. And using the proposed antenna, we fabricate a polarization diversity any antenna and discuss the possibility of antenna for PCS base station.

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Estimation of Fracture Toughness Degradation of High Temperature Materials by Nonlinear Acoustic Effects (비선형 음향효과에 의한 고온 재료의 파괴인성 열화도 평가)

  • Jeong, Hyun-Jo;Nahm, Seung-Hoon;Jhang, Kyung-Young;Nam, Young-Hyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.5
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    • pp.424-430
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    • 2000
  • In order to develop an ultrasonic evaluation method for properties degradation of high temperature materials, a number of Cr-Mo-V steel samples were heat-treated and their damage mechanism was examined. Ultrasonic parameters such as velocity, attenuation, and more recently developed nonlinear acoustic parameter were measured. The nonlinear acoustic parameter was found to be most sensitive to material degradation mainly attributed to the precipitation of impurities in grain boundaries. When compared to the electrical resistivity results, the nonlinear parameters showed similar behavior. There existed a relatively good correlation between the nonlinear parameter and the fracture appearance transition temperature (FATT) obtained by Charpy V-notch impact test. Based on the relationship between the FATT and the fracture toughness ($K_{IC}$), correlation between the nonlinear parameter and $K_{IC}$ was established.

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Compensation for the Distorted Signals in WDM System with Non Zero-Dispersion Shifted Fiber Using Optical Phase Conjugator (비영 분산 천이 광섬유를 갖는 WDM 시스템에서 광 위상 공액기에 의한 왜곡된 광 신호의 보상)

  • Lee Seong-Real
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.6 s.109
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    • pp.546-555
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    • 2006
  • In this paper, the numerical methods of finding the optimal position of optical phase conjugator(OPC) and the optimal fiber dispersions are proposed, which are able to effectively compensate overall channels in $8{\times}40$ Gbps WDM system with non zero-dispersion shifted fiber(NZ-DSF) as an optical fiber. And the compensation characteristics in the system with two induced optimal parameters are compared with those in the system with mid-span spectral inversion (MSSI) technique in order to confirm the availability of the proposed methods. It is confirmed that the optimal parameter values induced in this approach are very useful to effectively compensate overall channels in WDM system with OPC. And, it is confirmed that two optimal parameters depend on each other, but less related with the searching procedure. The methods proposed in this research will be expected to alternate with the method of making a symmetrical distribution of power and local dispersion in real optical link which is a serious problem of applying the OPC into multi-channels WDM system.

Compensation for Distorted RZ Signals in 8×40 Gbps WDM System with NZ-DSF using Modified MSSI (NZ-DSF를 갖는 8×40 Gbps WDM 시스템에서 개량된 MSSI 기법을 이용한 왜곡된 RZ 신호의 보상)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.10 no.3
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    • pp.205-212
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    • 2006
  • In this paper, the numerical methods of searching the optimal position of optical phase conjugator (OPC) and the optimal dispersion coefficients of fiber sections are proposed, which are able to effectively compensate overall channels in $8{\times}40$ Gbps WDM system with non zero - dispersion shifted fiber (NZ-DSF) as an optical fiber. And the compensation characteristics in the system with two induced optimal parameters are compared with those in the system with the currently used mid-span spectral inversion (MSSI) in order to verify the availability of the proposed methods. It is confirmed that the compensation extents of the distorted 8-channel signals are improved within 2 dB power penalty by applying the induced optimal parameters into WDM system. It is also confirmed that two optimal parameters less related with the searching procedure of these optimal values, only if these depend on each other.

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Design of FIR Halfband Filters using Generalized Lagrange Polynomial (일반화된 라그랑지 다항식을 사용하는 FIR 하프밴드 필터 설계)

  • Bong, Jeongsik;Jeon, Joonhyeon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.10
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    • pp.188-198
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    • 2013
  • Maximally flat (MAXFLAT) half-band filters usually have wider transition band than other filters. This is due to the fact that the maximum possible number of zeros at $z={\pm}1$ is imposed, which leaves no degree of freedom, and thus no independent parameters for direct control of the frequency response. This paper describes a novel method for the design of FIR halfband filters with an explicit control of the transition-band width. The proposed method is based on a generalized Lagrange halfband polynomial (g-LHBP) with coefficients parametizing a 0-th coefficient $h_0$, and allows the frequency response of this filter type to be controllable by adjusting $h_0$. Then, $h_0$ is modeled as a steepness parameter of the transition band and this is accomplished through theoretically analyzing a polynomial recurrence relation of the g-LHBP. This method also provides explicit formulas for direct computation of design parameters related to choosing a desired filter characteristic (by trade-off between the transition-band sharpness and passband & stopband flatness). The examples are shown to provide a complete and accurate solution for the design of such filters with relatively sharper transition-band steepness than MAXFLAT half-band filters.

A Speech Synthesis System based on Cepstral Parameters and Multiband Excitation Signal (켑스트럼 파라미터와 다중대역 여기신호를 사용한 음성 합성 시스팀)

  • 김기순
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1995.06a
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    • pp.211-215
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    • 1995
  • 명료하고 자연스러운 한국어 음성을 생성하기 위하여 다중대역 여기신호를 이용한 음성 합성 시스팀을 제안한다. 분석계에서는 켑스트럼 파라미터를 사용하여 유성/무성 판별 스펙트럼을 이용한 유/무성 구간 자동판별법을 제안하고, 현재 단순 임펄스와 백색잡음만으로도 구성된 음원과 간단한 유성/무성 판별로 구동되어지는 합성음의 음질상의 한계를 개선하기 위하여 합성계에서는 음질개선 방안으로 유성음 구동시 다중대역 여기신호를 도입하여 합성시 이용한다. 제안된 방법에 대한 청취실험을 한 결과, 유성음 부분 특히 잡음이 많이 섞여 있는 유성음화 마찰음과 모음의 천이부분 등에서 일반적으로 사용되고 있는 간단한 유성/무성 파라미터를 사용한 합성음에 비하여 다중대역 여기신호를 사용한 합성음의 명료도가 매우 우수함을 확인하였다.

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