• 제목/요약/키워드: filters

검색결과 4,199건 처리시간 0.027초

경계 강도 기반의 적응적 보간 필터 (Boundary Strength based Adaptive Interpolation Filter)

  • 송윤석;최정아;호요성
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2014년도 하계학술대회
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    • pp.26-27
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    • 2014
  • This paper presents an adaptive interpolation filtering scheme for the High Efficiency Video Coding (HEVC) standard. In regards to interpolation for motion estimation and compensation, the conventional HEVC employs 8-tap and 4-tap filters for luma and chroma samples, respectively. Coefficients in such filters are determined by discrete cosine transform (DCT). In the proposed scheme, boundary strength values are stored after the execution of the deblocking filter. For each block, the sum of boundary strength values is calculated to indicate whether its region is complex or simple. Consequently, based on the region classification, 12-tap and 8-tap interpolation filters are used for complex and simple regions, respectively. This process is applied to luma sample interpolation only. Simulation results show 1.8% average BD-rate reduction compared to the conventional method.

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정수처리공정에서의 입자분석 적용방안 (Application of Particle Counter in Water Treatment Process)

  • 신상희;전현숙;이찬형;배기수
    • 한국물환경학회지
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    • 제29권3호
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    • pp.337-342
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    • 2013
  • The particle counter compared with the turbidimeter provides good precision and sensitivity and can get the characteristics of particulates effectively. The purpose of this study is to provide the application of particle counter in sand and activated carbon filters. The particle count by size could be more easily sense when the water quality is changed by the influent of high turbidity or algae. We could decide the optimal backwashing cycles and detect the efficiencies of filters by monitoring the total particle count of effluent in sand and activated carbon filters.

능동소음제어를 위한 IIR 구조 2차경로 추정 알고리즘 (IIR Structure Secondary Path Estimation Algorithms for Active Noise Control Systems)

  • 최영훈;안동준;남현도
    • 조명전기설비학회논문지
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    • 제25권2호
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    • pp.143-149
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    • 2011
  • In this paper, IIR structures are proposed to reduce the computation complexity of the secondary-pass estimation in active noise control(ANC) systems. However, there are stability problems of using IIR models to reduce the computation complexity in ANC systems. To overcome these problems, we propose a stabilizing procedure of recursive least mean squares (RLMS) algorithms for eatimating the parameters of IIR models of the secondary path transfer functions. The multichannel ANC systems are implemented by using the TMS320C6713 DSP board to test the performance of computation complexity and stability of the proposed methods. Comparing the IIR filters with the FIR filters, the IIR filters can reduce 50[%] of the computation and obtain similar noise reduction result.

다중모드 도파로와 홀로그램 필터를 이용한 광신호 교환 (Optical switching by use of a multimode waveguide and hologram filters)

  • 신동학
    • 한국정보통신학회논문지
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    • 제9권1호
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    • pp.199-203
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    • 2005
  • $M{\times}1$의 다중모드 도파로와 N개의 홀로그램 필터를 이용하여 M개 입력단자와 N개 출력단자 사이에 광신호 교환을 수행할 수 있는 방법을 제안한다. 광신호 경로는 $M{\times}1$의 다중모드 도파로를 사용하고, 이것으로부터 발생하는 스페클 패턴들을 연결 목적지를 결정하는 목적코드로 이용한다. 제안한 시스템에 대해 광신호 교환이 가능함을 실험적으로 보였다.

Effects of Photon Energy Spectrum on the Photocurrent of Hydrogenated Amorphous Silicon Thin Film Transistor by Using Frequency Filters

  • Cho, Eou Sik;Kwon, Sang Jik
    • Transactions on Electrical and Electronic Materials
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    • 제14권1호
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    • pp.16-19
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    • 2013
  • Frequency filters with various filtering wavelengths were used in the photoelectric characterization of hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) and the experimental results were described and analyzed in terms of the photon energy spectral characteristics calculated from the integration of the photon energy and the spectral intensity of transmitted backlight through the filters at each wavelength. From the comparison of the photocurrents and the calculated photon energy spectrums for the filtered ranges of wavelength, it was possible to conclude that the photocurrents are closely related to the photon energy spectrums of the backlight.

전류형 능동필터를 위한 델타변조제어기법의 디지탈 구현 (Digital Implementation of Delta Modulation Technique for Current-Fed Active Power Filters)

  • 강병희;황종규;고재석;목형수;최규하
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 A
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    • pp.400-402
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    • 1994
  • This paper presents a digital implementation of delta modulation Technique for Active Power Filters. Delta modulated scheme is to control the harmonic-compensating current indirectly by adjusting the capacitor voltage to be sinusoidal. The overall control system has two feedback loops. One is the outer propotional feedback for loop regulating the dc current of active filters and the other is the inner feedback loop for maintaining the ac current waveform to be sinusoidal, and have zero power factor angle(i.e. unity power factor). The characteristics of the proposed is investigated by digital simulation using ACSL and experimental results are obtained by TMS370C756 Single-Chip Microprocessor relative to analog delta modulation technique.

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잡음영향의 저감을 위한 두 디지털 필터들의 사용에 의한 DFT 기반의 계통주파수 추정 (DFT-based Power System Frequency Estimation using Two Digital Filters for Noise Effect Reduction)

  • 황진권
    • 전기학회논문지
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    • 제62권7호
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    • pp.891-897
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    • 2013
  • The power system frequency plays an important role in monitoring and controlling the power system. The frequency can be measured through discrete Fourier transform (DFT) coefficients of its positive fundamental frequency. The accuracy of the frequency estimate is severely affected by noise in the power system signal and the leakage effect of the negative fundamental frequency in DFT. This paper proposes a DFT-based frequency estimation algorithm to cope with the noise as well as the leakage effect. In this algorithm, two suitable digital filters are introduced to reduce efficiently frequency estimate error due to the noise. These filters are designed to use a digital bandpass filter and a second-degree integrator. The effectiveness of the proposed algorithm in reduction of frequency estimate error is verified through simulations on noise, harmonics and frequency deviation.

FILTERS OF RESIDUATED LATTICES BASED ON SOFT SET THEORY

  • JUN, YOUNG BAE;LEE, KYOUNG JA;PARK, CHUL HWAN;ROH, EUN HWAN
    • 대한수학회논문집
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    • 제30권3호
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    • pp.155-168
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    • 2015
  • Strong uni-soft filters and divisible uni-soft filters in residuated lattices are introduced, and several properties are investigated. Characterizations of a strong and divisible uni-soft filter are discussed. Conditions for a uni-soft filter to be divisible are established. Relations between a divisible uni-soft filter and a strong uni-soft filter are considered.

멀티프로세서 구조를 이용한 Wave Digital Filter의 구현 (Implementation of Wave Digital Filters Based on Multiprocessor Architecture)

  • 김형교
    • 한국정보통신학회논문지
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    • 제10권12호
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    • pp.2303-2307
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    • 2006
  • Wave Digital Filter(WDF)는 그 구조상 반올림 오차에 의한 잡음에 아주 강하기 때문에 필터로 구현되는 DSP 알고리듬에 있어 그 필터의 계수의 단어길이가 짧을 경우 아주 유용하게 이용될 수 있다. 본 논문에서는 멀티프로세서 구조를 채택하여 입력의 샘플링 속도, 프로세서의 수, 그리고 주어진 입력에 대한출력의 지연에 있어 최적인 WDF를 구현하고자 한다. 이 구현은 제어신호를 포함한 완전한 회로도로 주어지며, 이 화로도는 기존의 실리콘 컴 파일러를 이용하여 VLSI 레이아웃으로 용이하게 변환 될 수 있다.

Modified Compact Combline Filter Using Planar Parallel Coupled Structure with Extended Rejection Bandwidth

  • Kang, In-Ho;Wang, Kai;Li, Shang MIng
    • 한국항해항만학회지
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    • 제34권7호
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    • pp.543-552
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    • 2010
  • Modified compact combline bandpass filters are proposed based on the miniaturized quarter-wave transmission line which is composed of the parallel coupled line and lumped capacitors. The electrical length of the parallel coupled line in a resonator, which determines the size of combline bandpass filters, is just $5^{\circ}$ or $7^{\circ}$, resulting in a compact circuit area. The designed combline bandpass filter also has a wide upper stopband by suppressing the spurious passbands, not moving. Measured results of two fabricated filters centered at 400MHz show good agreement with the theoretical predications.