• Title, Summary, Keyword: Wavelet

Search Result 3,445, Processing Time 0.038 seconds

On Normalized Tight Frame Wavelet Sets

  • Srivastava, Swati
    • Kyungpook Mathematical Journal
    • /
    • v.55 no.1
    • /
    • pp.127-135
    • /
    • 2015
  • We determine two-interval normalized tight frame wavelet sets for real dilation $d{\in}(1,{\infty})$, and characterize all symmetric normalized tight frame wavelet sets. We also construct a normalized tight frame wavelet set which has an infinite number of components accumulating at the origin. These normalized tight frame wavelet sets and their closures possess the same measure. Finally an example of a normalized tight frame wavelet set is provided whose measure is strictly less than the measure of its closure.

Wavelet Algorithms for Remote Sensing

  • CHAE Gee Ju;CHOI Kyoung Ho
    • Proceedings of the KSRS Conference
    • /
    • /
    • pp.224-227
    • /
    • 2004
  • From 1980's, the DWT(Discrete Wavelet Transform) is applied to the data/image processing. Many people use the DWT in remote sensing for diversity purposes and they are satisfied with the wavelet theory. Though the algorithm for wavelet is very diverse, many people use the standard wavelet such as Daubechies D4 wavelet and biorthogonal 9/7 wavelet. We will overview the wavelet theory for discrete form which can be applied to the image processing. First, we will introduce the basic DWT algorithm and review the wavelet algorithm: EZW (Embedded Zerotree Wavelet), SPIHT(Set Partitioning in Hierarchical Trees), Lifting scheme, Curvelet, etc. Finally, we will suggest the properties of wavelet algorithm; and wavelet filter for each image processing in remote sensing.

  • PDF

A Study on the Application of Wavelet Transform to Faults Current Discrimination (Wavelet 변환을 이용한 고장전류의 판별에 관한 연구)

  • 조현우;정종원;윤기영;김태우;이준탁
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • /
    • pp.213-217
    • /
    • 2002
  • Recently the subject of "wavelet analysis" has be drawn by both mathematical and engineering application fields such as Signal Processing, Compression/Decomposition, Wavelet-Neural Network, Statistics and etc. Even though its similar to courier analysis, wavelet is a versatile tool with much mathematical content and great potential for applications. Especially, wavelet transform uses localizable various mother wavelet functions in time-frequency domain. Therefore, wavelet transform has good time-analysis ability for high frequency component, and has good frequency-analysis ability for low frequency component. Using the discriminative ability is more easy method than other conventional techniques. In this paper, Morlet wavelet transform was applied to discriminate the kind of line fault by acquired data from real power transformation network. The experimental result presented that Morlet wavelet transform is easier, and more useful method than the FFW (Fast courier Transform).ransform).

  • PDF

IMAGE QUALITY OPTIMIZATION BASED ON WAVELET FILTER DESIGN AND WAVELET DECOMPOSITION IN JPEG2000

  • Quan, Do;Ho, Yo-Sung
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • /
    • pp.7-12
    • /
    • 2009
  • In JPEG2000, the Cohen-Daubechies-Feauveau (CDF) 9/7-tap wavelet filter adopted in lossy compression is implemented by the lifting scheme or by the convolution scheme while the LeGall 5/3-tap wavelet filter adopted in lossless compression is implemented just by the lifting scheme. However, these filters are not optimal in terms of Peak Signal-to-Noise Ratio (PSNR) values, and irrational coefficients of wavelet filters are complicated. In this paper, we proposed a method to optimize image quality based on wavelet filter design and on wavelet decomposition. First, we propose a design of wavelet filters by selecting the most appropriate rational coefficients of wavelet filters. These filters are shown to have better performance than previous wavelet ones. Then, we choose the most appropriate wavelet decomposition to get the optimal PSNR values of images.

  • PDF

Growing Algorithm of Wavelet Neural Network (웨이블렛 신경망의 성장 알고리즘)

  • 서재용;김성주;김성현;김용민;전홍태
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • /
    • pp.57-60
    • /
    • 2001
  • In this paper, we propose growing algorithm of wavelet neural network. It is growing algorithm that adds hidden nodes using wavelet frame which approximately supports orthogonality in wavelet neural network based on wavelet theory. The result of this processing can be reduced global error and progresses performance efficiency of wavelet neural network. We apply the proposed algorithm to approximation problem and evaluate effectiveness of proposed algorithm.

  • PDF

HIGH ACCURACY POINTS OF WAVELET APPROXIMATION

  • Kwon, Soon-Geol
    • Journal of applied mathematics & informatics
    • /
    • v.27 no.1_2
    • /
    • pp.69-78
    • /
    • 2009
  • The accuracy of wavelet approximation at resolution h = $2^{-k}$ to a smooth function f is limited by O($h^M$), where M is the number of vanishing moments of the mother wavelet ${\psi}$; that is, the approximation order of wavelet approximation is M - 1. High accuracy points of wavelet approximation are of interest in some applications such as signal processing and numerical approximation. In this paper, we prove the scaling and translating properties of high accuracy points of wavelet approximation. To illustrate the results in this paper, we also present two examples of high accuracy points of wavelet approximation.

  • PDF

Faults Current Discrimination of Power System Using Wavelet Transform (웨이블렛 변환을 이용한 전력시스템 고장전류의 판별)

  • Lee, Joon-Tark;Jeong, Jong-Won
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.21 no.3
    • /
    • pp.75-81
    • /
    • 2007
  • Recently the subject of "wavelet analysis" has be drawn by both mathematical and engineering application fields such as Signal Processing, Compression/Decomposition, Wavelet-Neural Network, Statistics and etc. Even though its similar to Fourier analysis, wavelet is a versatile tool with much mathematical content and great potential for applications. Especially, wavelet transform uses localizable various mother wavelet functions in time-frequency domain. Therefore, wavelet transform has good time-analysis ability for high frequency component, and has good frequency-analysis ability for low frequency component. Using the discriminative ability is more easy method than other conventional techniques. In this paper, Morlet wavelet transform was applied to discriminate the kind of line fault by acquired data from real power transformation network. The experimental result presented that Morlet wavelet transform is easier, and more useful method than the Fast Fourier Transform(FFT).

Analysis of Ringing by Continuous Wavelet (연속 웨이브렛에 의한 Ringing현상 해석)

  • 권순홍;이형석;하문근
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • /
    • pp.118-122
    • /
    • 2000
  • In this study, Ringing is investigated by continuous wavelet transform. Ringing is considered to be one of the typical transient phenomena in the field of ocean engineering. The wavelet analysis is adopted to analyze ringing from the point that wavelet analysis is capable of frequency analysis as well as time domain analysis. The use mother wavelet is the Morlet wavelet. The relation between the frequency of the time series and that of wavelet can be clearly defined with Mor1et wavelet. Experimental data obtained by other researchers was used. The wave height time series and acceleration times series of the surface piercing cylinder were analyzed. The results show that the proposed scheme can detect typical frequency region by the time domain analysis which could hardly be detected if one relied on the frequency analysis.

  • PDF

Denoising of Speech Signal Using Wavelet Transform (웨이브렛 변환을 이용한 음성신호의 잡음제거)

  • 한미경;배건성
    • The Journal of the Acoustical Society of Korea
    • /
    • v.19 no.5
    • /
    • pp.27-34
    • /
    • 2000
  • This paper deals with speech enhancement methods using the wavelet transform. A cycle-spinning scheme and undecimated wavelet transform are used for denoising of speech signals, and then their results are compared with that of the conventional wavelet transform. We apply soft-thresholding technique for removing additive background noise from noisy speech. The symlets 8-tap wavelet and pyramid algorithm are used for the wavelet transform. Performance assessments based on average SNR, cepstral distance and informal subjective listening test are carried out. Experimental results demonstrate that both cycle-spinning denoising(CSD) method and undecimated wavelet denoising(CWD) method outperform conventional wavelet denoising(UWD) method in objective performance measure as welt as subjective listening test. The two methods also show less "clicks" that usually appears in the neighborhood of signal discontinuities.

  • PDF

An Efficient Adaptive Wavelet-Collocation Method Using Lifted Interpolating Wavelets (수정된 보간 웨이블렛응 이용한 적응 웨이블렛-콜로케이션 기법)

  • Kim, Yun-Yeong;Kim, Jae-Eun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.24 no.8
    • /
    • pp.2100-2107
    • /
    • 2000
  • The wavelet theory is relatively a new development and now acquires popularity and much interest in many areas including mathematics and engineering. This work presents an adaptive wavelet method for a numerical solution of partial differential equations in a collocation sense. Due to the multi-resolution nature of wavelets, an adaptive strategy can be easily realized it is easy to add or delete the wavelet coefficients as resolution levels progress. Typical wavelet-collocation methods use interpolating wavelets having no vanishing moment, but we propose a new wavelet-collocation method on modified interpolating wavelets having 2 vanishing moments. The use of the modified interpolating wavelets obtained by the lifting scheme requires a smaller number of wavelet coefficients as well as a smaller condition number of system matrices. The latter property makes a preconditioned conjugate gradient solver more useful for efficient analysis.