• Title/Summary/Keyword: Gibbs phenomenon

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ON GIBBS CONSTANT FOR THE SHANNON WAVELET EXPANSION

  • Shim, Hong-Tae
    • Journal of applied mathematics & informatics
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    • v.4 no.2
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    • pp.529-534
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    • 1997
  • Even though the Shannon wavelet is a prototype of wavelets are assumed to have. By providing a sufficient condition to compute the size of Gibbs phe-nomenon for the Shannon wavelet series we can see the overshoot is propotional to the jump at discontinuity. By comparing it with that of the Fourier series we also that these two have exactly the same Gibbs constant.

A Study on Digital Filter Design based on High-order Window Function (고차 창함수 기반의 디지털필터 설계에 관한 연구)

  • Bae, Sang-Bum;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.973-976
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    • 2009
  • Digital signal processing technique use to variety fields including communication. For these signal processing, FIR digital filter is representative. And for FIR digital filter designing, the window function is used to reduce the Gibbs phenomenon which occurs in the coefficient cutting process of the ideal filter. Therefore, in this paper to improve performance of digital filter, a high-order window function was applied. In this simulation, we compared a peak side-lobe and a transient characteristics with the existing window function.

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A Study on Performance Improvement of Modified Window Function (변형된 창함수의 성능향상에 관한 연구)

  • Lee, Kyung-Hyo;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.05a
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    • pp.925-928
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    • 2008
  • With basis of the development of information communication techniques in recent year, the digital processing techniquy also has been growed fast. The digital processing technique have used signals - speech and image processing- for processing of transmission and analysis. After we get and save the signals. Effective signal processing techniques have varied filters and typical digital filters are FIR filter and IIR filter. The FIR digital filter is more secure because phase response characteristics have linear phase. But, FIR digital filters have a problem to product the Gibbs phenomenon generating around a discontinuous point. A propose of filer is to remove the problem. Therefore, in this paper I was proposed a method using FIR digital filter applied a modified window function and the method was compared with conventional methods.

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A Study on FIR Digital filter using Window Function (Window 함수를 이용한 FIR 디지털필터에 관한 연구)

  • 구본석;배상범;김남호
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.68-74
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    • 2004
  • The use of digital filters in the signal processing field is increasing rapidly with development of the modem industrial society, and generally digital filter is classified into FIR (infinite impulse response) fillers and FIR (finite impulse response) filters. The FIR digital filter has the phase linearity and the easiness of creation. In the design of the FIR digital filter, the window function is used to alleviate ripples caused by Gibbs Phenomenon around the cut-off frequency of the passband. In this paper, we designed a new window function and compared with existing Manning, Hamming and Blackman window functions. And we used peak side-lobe and transient characteristics as standard of judgement.

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Fourier Modal Method for Optical Dipole Radiation in Photonic Structures

  • Park, Sungjae;Hahn, Joonku;Kim, Hwi
    • Current Optics and Photonics
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    • v.5 no.6
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    • pp.597-605
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    • 2021
  • An extended Fourier modal method (FMM) for optical dipole radiation in three-dimensional photonic structures is proposed. The core elements of the proposed FMM are the stable bidirectional scattering-matrix algorithm for modeling internal optical emission, and a novel optical-dipole-source model that prevents numerical errors induced by the Gibbs phenomenon. Through the proposed scheme, the FMM is extended to model a wide range of source-embedded photonic structures.

A Study on Performance Improvement of FIR Digital Filter using Modified Window Function (변형된 창함수를 이용한 FIR 디지털 필터의 성능 향상에 관한 연구)

  • Kim, Nam-Ho;Ku, Bon-Seok
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.758-761
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    • 2007
  • Digital signal processing technique is applied in wide fields such as speech processing, image processing and spectrum analysis. Therefore, in order to do frequency selective operation digital filter is used in stead of analog filter and sharp filter characteristics can be implemented. Since finite impulse response (FIR) digital filter as nonrecursive type represents linear phase response characteristics and is always stable and is used in fields regarding wave information importantly such as data transmission. And due to frequency characteristics, in order to remove the Gibbs phenomenon generating around a discontinuous point, filter is designed through window function method. Therefore, in this paper to improve performance of FIR digital filter, a modified window function was applied. And the proposed method was compared with conventional methods using peak side-lobe and transition properties in simulations.

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A Study on an Performance Improvement of FIR Digital Filter using Window Function Design Method (창함수 설계 기법을 이용한 FIR 디지털 필터의 성능 향상에 관한 연구)

  • Lee, Kyung-Hyo;Bae, Sang-Bum;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.351-354
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    • 2007
  • In recent years, digital processing techniques have been applied diversity of fields. Typical signal processing techniques are speech processing and image processing. And filters for the signal processing can be divided in FIR (finite impulse response) filter and IIR (infinite impulse response) filter. Compared with IIR filter, the FIR Filter has a defect of high-degree, but has a merit of stability and uses simply. Futhermore, FIR filter also has linear phase response characteristics, it is using in fields regarding wave information importantly. To FIR Filter design, the main issue is to remove the Gibbs phenomenon. Therefore, in this paper I was proposed a method using FIR digital filter applied a modified window function and the method was compared with conventional methods.

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The Bayesian Analysis for Software Reliability Models Based on NHPP (비동질적 포아송과정을 사용한 소프트웨어 신뢰 성장모형에 대한 베이지안 신뢰성 분석에 관한 연구)

  • Lee, Sang-Sik;Kim, Hee-Cheul;Kim, Yong-Jae
    • The KIPS Transactions:PartD
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    • v.10D no.5
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    • pp.805-812
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    • 2003
  • This paper presents a stochastic model for the software failure phenomenon based on a nonhomogeneous Poisson process (NHPP) and performs Bayesian inference using prior information. The failure process is analyzed to develop a suitable mean value function for the NHPP; expressions are given for several performance measure. The parametric inferences of the model using Logarithmic Poisson model, Crow model and Rayleigh model is discussed. Bayesian computation and model selection using the sum of squared errors. The numerical results of this models are applied to real software failure data. Tools of parameter inference was used method of Gibbs sampling and Metropolis algorithm. The numerical example by T1 data (Musa) was illustrated.

Investigation of the Convergence Behavior with Fluctuation Features in the Fourier Modal Analysis of a Metallic Grating

  • Kim, Hwi;Park, Gwanwoo;Kim, Changsoon
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.196-202
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    • 2012
  • We observe that the transmission and reflection efficiencies of a one-dimensional metallic grating under transverse-magnetic illumination calculated using the Fourier modal method (FMM) with the Fourier factorization rules have peculiar fluctuations, albeit small in magnitude, as the number of field harmonics increases. It is shown that when the number of Fourier terms for the electromagnetic field is increased from that in the conventional FMM, the fluctuations due to non-convergent highly evanescent eigenmodes can be eliminated. Our examination reveals that the fluctuations originate from the Gibbs phenomenon inherent in the Fourier-series representation of a permittivity function with discontinuities, and from non-convergence of highly evanescent internal Bloch eigenmodes.

A Study on the FIR Digital Filter using Modified Window Function (변형된 창함수를 사용한 FIR 디지털 필터에 관한 연구)

  • 강경덕;배상범;김남호;류지구
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.1
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    • pp.49-55
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    • 2003
  • The use of digital filters in the signal process field is increasing rapidly with development of the modern industrial society. Especially, detail processors, Y/C separators, ghost removing filters, standard converters (NTSC to PAL or PAL to NTSC) and noise reducers, all of which use digital filters, tend to be used in digital video and audio processing, CATV and various communication fields. Generally, there are two different digital filters, the Rf (infinite impulse response) filter and the FIR (finite impulse response) filter in digital filter. In this paper, we have designed FIR filter which has the phase linearity and the easiness of creation. In the design of the FIR digital filter, the window function is used to alleviate the ripples caused by Gibbs Phenomenon around the cut off frequency of the band pass. But there're some problems to choose proper window function for the design destination due to its fixed values. Therefore, in this paper, we designed a modified Hanning window with new parameter which is adaptively chosen corresponding to design objectives. The digital filter was simulated to prove the validity of the model and it was compared with the Hamming, the Manning, the Blacknan and the Kaiser window function. And we have used peak side-lobe and transient characteristics as standard of judgement.

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