• Title/Summary/Keyword: Transform

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Detection of Chatter using Wavelet Transform (웨이브렛 변환을 이용한 채터 검출)

  • Oh, Sang-Lok;Chin, Do-Hum;Yoon, Moon-Chul;Ryoo, In-Ill;Ha, Man-Kyung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.2
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    • pp.32-38
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    • 2004
  • The chatter behaviour in endmilling is a complex and nonlinear phenomenon, so it is very difficult to detect and diagnose this chatter phenomenon, This paper presents new method for the detection of chatter in endmilling operation based on the wavelet transform. In this paper, the fundamental property of the wavelet transform is reviewed by comparing the spectrum of other algorithm such as FFT. This result using wavelet transform shows the possibiling of the chatter detection in endmilling operation.

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An Analysis on Face Recognition system of Housdorff Distance and Hough Transform (Housdorff Distance 와 Hough Transform을 적용한 얼굴인식시스템의 분석)

  • Cho, Meen-Hwan
    • Journal of the Korea Computer Industry Society
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    • v.8 no.3
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    • pp.155-166
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    • 2007
  • In this paper, captured face-image was pre-processing, segmentation, and extracting features from thinning by differential operator and minute-delineation. A straight line in slope-intercept form was transformed at the $r-\theta$ domain using Hough Transform, instead of Housdorff distance are extract feature as length, rotation, displacement of lines from thinning line components by differentiation. This research proposed a new approach compare with Hough Transformation and Housdorff Distance for face recognition so that Hough transform is simple and fast processing of face recognition than processing by Housdorff Distance. Rcognition accuracy rate is that Housdorff method is higher than Hough transformation's method.

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SWT (Stationary Wavelet Transform)을 이용한 영상 잡음 제거

  • Yu, Hye-Rim;Jo, Hyeon-Suk;Lee, Hyeong;Lee, In-Jeong
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2007.05a
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    • pp.9-28
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    • 2007
  • It is well known that wavelet transform is a signal processing technique which can display the signals on in both time and frequency domain. In this paper, we proposed a new approach based on stationary wavelet transform to provide an enhanced approach for eliminating noise. A 'stationary wavelet transform', where the coefficient sequences are not decimated at each stage, is described. The testing result on sample iris images has shown an enhanced image quality and also show that it has a superior performance than traditional discrete wavelet transform.

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INVERSION OF THE CLASSICAL RADON TRANSFORM ON ℤnp

  • Cho, Yung Duk;Hyun, Jong Yoon;Moon, Sunghwan
    • Bulletin of the Korean Mathematical Society
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    • v.55 no.6
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    • pp.1773-1781
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    • 2018
  • The Radon transform introduced by J. Radon in 1917 is the integral transform which is widely applicable to tomography. Here we study the discrete version of the Radon transform. More precisely, when $C({\mathbb{Z}}^n_p)$ is the set of complex-valued functions on ${\mathbb{Z}}^n_p$. We completely determine the subset of $C({\mathbb{Z}}^n_p)$ whose elements can be recovered from its Radon transform on ${\mathbb{Z}}^n_p$.

The Detection of Gear Failures Using Wavelet Transform (웨이브렛변환을 이용한 기어결함의 진단)

  • Park, Sung-Tae;Gim, Jae-Woong;Yang, Jianguo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.617-622
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    • 2002
  • This paper presents that the Wavelet Transform can be used to detect the various local defects in a gearbos. Two types of defects which are broken tooth and localized wear, are experimented and the signals are collected by accerometer and analyzed. Because of the complecity of the signals acquired from sensor, it is needed to identify the interesting signal. The natural frequencies of shafts and the gear mesh frequency(GMF) is calculated theretically. DWT, CWT and the aplication are used to extract a gear-localized defect feature from the vibration signal of the gearbox with the defective gear. The results shows the transform is more effective to detect the failures than the Fourier Transform.

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Combinational Logic Optimization for a Hardware based HEVC Transform

  • Tamse, Anish;Lee, Hyuk Jae;Rhee, Chae Eun
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2014.11a
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    • pp.10-11
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    • 2014
  • In a 2-dimensional (2D) Discrete Cosine Transform (DCT) hardware, a significant fraction of the total hardware area is contributed by the combinational logic used to perform 1-dimensional (2D) transform. The size of the non-combinational logic i.e. the transpose memory is dictated by the size of the largest transform supported. Hence, the optimization of hardware area is performed mainly for 1D-transform combinational logic. This paper demonstrates the use of Multiple Constant Multiplication (MCM) algorithm to reduce the combinational logic area. Partial optimizations are also described for the cases where the direct use of MCM algorithm doesn't meet the timing constraint. Experimental results show that 46% improvement in gate count is achieved for 32 point 1D DCT transform logic after using MCM optimization.

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CERTAIN FRACTIONAL INTEGRALS AND IMAGE FORMULAS OF GENERALIZED k-BESSEL FUNCTION

  • Agarwal, Praveen;Chand, Mehar;Choi, Junesang;Singh, Gurmej
    • Communications of the Korean Mathematical Society
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    • v.33 no.2
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    • pp.423-436
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    • 2018
  • We aim to establish certain Saigo hypergeometric fractional integral formulas for a finite product of the generalized k-Bessel functions, which are also used to present image formulas of several integral transforms including beta transform, Laplace transform, and Whittaker transform. The results presented here are potentially useful, and, being very general, can yield a large number of special cases, only two of which are explicitly demonstrated.

An overview on applications of wavelet transform in power systems (전력시스템에서의 웨이브릿 변환 적용 사례)

  • Kim, Chang-Il;Yu, In-Keun
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.369-372
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    • 2000
  • An overview on applications of wavelet transform in power systems presented in this paper. Wavelet transform is capable of making trade-offs between time and frequency resolutions, which is a property that makes it appropriate for the analysis of non stationary signal. In recent years, wavelet transform is widely accepted as a technology offering an alternative way due to its flexibility in representation of non-stationary signal even in power systems. This paper presents various applications of wavelet transform in power systems. Wavelet transform has been used by the authors in the field of power system protection for the classification of transient signals, and forecasting of short term loads and system marginal price and so on. Various research works carried out by many researchers in power systems are summarized.

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Image registration using Hough transform and Phase correlation in Wavelet domain

  • Summar, Bhuttichai;Chitsobhuk, Orachat;Kasemsiri, Watjanapong
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2006-2009
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    • 2005
  • This paper presents a method for registering images using phase correlation technique in fourier domain, hough transform and multi-resolution wavelet. To register images, source and input images are transformed to wavelet domain. An angular transition can be obtained by applying hough transform technique followed by phase correlation. Then we apply phase correlation technique to find x-axis and y-axis transition. We apply wavelet transform to reduce processing time and also use its coefficients as edge information instead of canny detector. With multi-resolution property of wavelet transform, registration time can be greatly reduced. After we get all transition parameters, we transform the input images according to these parameters. Then, we compose and blend all images into a new large image with details of all source images. From our experiment, we can find the accurate transition both x-y translation and angular transition with less error.

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A Generalized Fourier Transform Based on a Periodic Window

  • Yoo, Kyung-Yul
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.4E
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    • pp.53-57
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    • 1996
  • An extension of the well-known Fourier transform is developed in this paper. It is denoted as the generalized Fourier transform(GFT), since it encompasses the Fourier transform as its special case. The first idea of this extension can be found on [1]. In the definition of the N-point discrete GFT, it first construct a passband in time which functions as a window in the time domain. An appropriate interpretation of each variables are introduced during the definition of the GFT, followed by the formal derivation of the inverse GFT. This transform pair is similar to the windowing in the frequency domain such as the subband coding technique (or filter bank approach) and could be extended to the wavelet transform.

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