• Title/Summary/Keyword: transform

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Numerical Inversion Technique for the One and Two-Dimensional L2-Transform Using the Fourier Series and Its Application to Fractional Partial Differential Equations

  • Aghili, Arman;Ansari, Alireza
    • Kyungpook Mathematical Journal
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    • v.52 no.4
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    • pp.383-395
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    • 2012
  • In this paper, we use a computational algorithm for the inversion of the one and two-dimensional $\mathcal{L}_2$-transform based on the Bromwich's integral and the Fourier series. The new inversion formula can evaluate the inverse of the $\mathcal{L}_2$-transform with considerable accuracy over a wide range of values of the independent variable and can be devised for the functions which are not Laplace transformable and have damping motion in small interval near origin.

Edge-Based Matching Using Generalized Hough Transform and Chamfer Matching (Generalized Hough Transform과 Chamfer 정합을 이용한 에지기반 정합)

  • Cho, Tai-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.1
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    • pp.94-99
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    • 2007
  • In this paper, a 2-dimensional edge-based matching algorithm is proposed that combines the generalized Hough transform (GHT) and the Chamfer matching to complement weakness of either method. First, the GHT is used to find approximate object positions and orientations, and then these positions and orientations are used as starling parameter values to find more accurate position and orientation using the Chamfer matching. Finally, matching accuracy is further refined by using a subpixel algorithm. The algorithm was implemented and successfully tested on a number of images containing various electronic components.

2-Dimensional Image Recovery Method Using Hadamard Transform (하다마드변환을 이용한 2차원 영상복원법)

  • Seo, Ik-Su;Park, Young-Jae;Lee, Tae-Hoon;Yoon, Tae-Sung;Park, Jin-Bae
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.1017-1019
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    • 1999
  • In this paper we present 2-dimensional image recovery method using Hadamard transform. Generally, the methods of Hadamard transform are more useful tools and much simplier than those of Fourier transform. The Hadamard transform can improve estimates when the detector is the source of noise. We take into account nonidealities in the system for the further improved image We also present the average mean square error(AMSE) associated with estimates with the results from computer simulations.

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Design of Unified Transform and Quantization Circuit for H.264/JPEG CODEC (H.264/JPEG 코덱을 위한 통합 변환 및 양자화 회로 설계)

  • Kim, Joon-Ho;Chun, Dong-Yeob;Lee, Seon-Young;Cho, Kyeong-Soon
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.401-402
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    • 2008
  • This paper presents an efficient architecture of unified transform and quantization circuit for H.264/JPEG CODEC. The proposed unified transform circuit shares adders required for all transform operations. The proposed unified quantization circuit uses four multipliers. Our transform circuit and quantization circuit consist of 33,711 gates and 9,650 gates respectively. The maximum operating frequency is 100MHz with 130nm standard cells.

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FOURIER'S TRANSFORM OF FRACTIONAL ORDER VIA MITTAG-LEFFLER FUNCTION AND MODIFIED RIEMANN-LIOUVILLE DERIVATIVE

  • Jumarie, Guy
    • Journal of applied mathematics & informatics
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    • v.26 no.5_6
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    • pp.1101-1121
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    • 2008
  • One proposes an approach to fractional Fourier's transform, or Fourier's transform of fractional order, which applies to functions which are fractional differentiable but are not necessarily differentiable, in such a manner that they cannot be analyzed by using the so-called Caputo-Djrbashian fractional derivative. Firstly, as a preliminary, one defines fractional sine and cosine functions, therefore one obtains Fourier's series of fractional order. Then one defines the fractional Fourier's transform. The main properties of this fractal transformation are exhibited, the Parseval equation is obtained as well as the fractional Fourier inversion theorem. The prospect of application for this new tool is the spectral density analysis of signals, in signal processing, and the analysis of some partial differential equations of fractional order.

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Analysis and Denoising of Cutting Force Using Wavelet Transform (Wavelet 변환을 이용한 절삭신호 분석과 노이즈 제거)

  • 하만경;곽재섭;진인태;김병탁;양재용
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.12
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    • pp.78-85
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    • 2002
  • The wavelet transform is a popular tool fer studying intermittent and localized phenomena in signals. In this study the wavelet transform of cutting force signals was conducted for the detection of a tool failure in turning process. We used the Daubechies wavelet analyzing function to detect a sudden change in cutting signal level. A preliminary stepped workpiece which had intentionally a hard condition was cut by the inserted cermet tool and a tool dynamometer obtained cutting force signals. From the results of the wavelet transform, the obtained signals were divided into approximation terms and detailed terms. At tool failure, the approximation signals were suddenly increased and the detailed signals were extremely oscillated just before tool failure.

Identification of Tool Breakage Signal Using Wavelet Transform of Feed Motor Current in Milling Operations (이송모터 전류신호의 Wavelet 변환에 의한 공구파손 식별)

  • Park, H.Y.;Kim, S.H.;Lee, M.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.9
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    • pp.31-37
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    • 1996
  • This Paper is concerned with effective signal identification method for tool breakage and micro chipping using discrete wavelet transform of feed motor current in milling operations. The wavelet transform uses an analyzing waveletfunction which is localized in both frequency and time domain to detect subtle time localized changes in input signals. The changing pattern of wavelet coefficient is continuously compared to detect tool breakage and micro chipping over one spindle revolution. The results indicate that the wavelet transform can identify tool failure with much greater sensi- tivity than the time domain monitoring and frequency domain monitoring such as FFT. Experimental results are presented to support the proposed scheme.

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Lane Detection using Embedded Multi-core Platform (임베디드 멀티코어 플랫폼을 이용한 차선검출)

  • Lee, Kwang-Yeob;Kim, Dong-Han;Park, Tae-Ryoung
    • Journal of IKEEE
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    • v.15 no.3
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    • pp.255-260
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    • 2011
  • In this paper, we propose a parallelization technique in lane detection by using Hough transform. Hough transform has a weakness that it has a lot computation quantity, because it has to compute ${\rho}$ value in all candidate ${\Theta}$ to be detected in an image. We propose an architecture of parallel processing for this transform in a multi-core environment. The parallel processing has application to Hough transform as well as noise reduction and edge detection. This proposed architecture has 5.17 times improvement in performance compare to the existing algorithm.

Application of wavelet transform in electromagnetics (Wavelet 변환의 전자기학적 응용)

  • Hyeongdong Kim
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.9
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    • pp.1244-1249
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    • 1995
  • Wavelet transform technique is applied to two important electromagnetic problems:1) to analyze the frequency-domain radar echo from finite-size targets and 2) to the integral solution of two- dimensional electromagnetic scattering problems. Since the frequency- domain radar echo consists of both small-scale natural resonances and large-scale scattering center information, the multiresolution property of the wavelet transform is well suited for analyzing such ulti-scale signals. Wavelet analysis examples of backscattered data from an open- ended waveguide cavity are presented. The different scattering mechanisms are clearly resolved in the wavelet-domain representation. In the wavelet transform domain, the moment method impedance matrix becomes sparse and sparse matrix algorithms can be utilized to solve the resulting matrix equationl. Using the fast wavelet transform in conjunction with the conjugate gradient method, we present the time performance for the solution of a dihedral corner reflector. The total computational time is found to be reduced.

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ANALYTIC FOURIER-FEYNMAN TRANSFORM AND CONVOLUTION OF FUNCTIONALS IN A GENERALIZED FRESNEL CLASS

  • Kim, Byoung Soo;Song, Teuk Seob;Yoo, Il
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.3
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    • pp.481-495
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    • 2009
  • Huffman, Park and Skoug introduced various results for the $L_{p}$ analytic Fourier-Feynman transform and the convolution for functionals on classical Wiener space which belong to some Banach algebra $\mathcal{S}$ introduced by Cameron and Storvick. Also Chang, Kim and Yoo extended the above results to an abstract Wiener space for functionals in the Fresnel class $\mathcal{F}(B)$ which corresponds to $\mathcal{S}$. Moreover they introduced the $L_{p}$ analytic Fourier-Feynman transform for functionals on a product abstract Wiener space and then established the above results for functionals in the generalized Fresnel class $\mathcal{F}_{A1,A2}$ containing $\mathcal{F}(B)$. In this paper, we investigate more generalized relationships, between the Fourier-Feynman transform and the convolution product for functionals in $\mathcal{F}_{A1,A2}$, than the above results.

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