• Title/Summary/Keyword: wavelet method

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Diagnosis of Pathological Speech Signals Using Wavelet Transform

  • Jo, Cheol-Woo;Kim, Dae-Hyun
    • Speech Sciences
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    • v.4 no.2
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    • pp.17-24
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    • 1998
  • In this paper a method to diagnose pathological voices using wavelet transform is sug gested. Pathological voices are collected from hospital and analyzed by the suggested method. Normal voices are collected separately and analyzed. Then the results are compared to find the differences in their characteristics. Three level wavelet transform is used. Normalized energy ratios between the levels and normalized peak-to-peak values are used as parameters. As a result, it was possible to distinguish between normal and pathological voices.

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Feature Extraction and Statistical Pattern Recognition for Image Data using Wavelet Decomposition

  • Kim, Min-Soo;Baek, Jang-Sun
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.831-842
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    • 1999
  • We propose a wavelet decomposition feature extraction method for the hand-written character recognition. Comparing the recognition rates of which methods with original image features and with selected features by the wavelet decomposition we study the characteristics of the proposed method. LDA(Linear Discriminant Analysis) QDA(Quadratic Discriminant Analysis) RDA(Regularized Discriminant Analysis) and NN(Neural network) are used for the calculation of recognition rates. 6000 hand-written numerals from CENPARMI at Concordia University are used for the experiment. We found that the set of significantly selected wavelet decomposed features generates higher recognition rate than the original image features.

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The construction of second generation wavelet-based multivariable finite elements for multiscale analysis of beam problems

  • Wang, Youming;Wu, Qing;Wang, Wenqing
    • Structural Engineering and Mechanics
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    • v.50 no.5
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    • pp.679-695
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    • 2014
  • A design method of second generation wavelet (SGW)-based multivariable finite elements is proposed for static and vibration beam analysis. An important property of SGWs is that they can be custom designed by selecting appropriate lifting coefficients depending on the application. The SGW-based multivariable finite element equations of static and vibration analysis of beam problems with two and three kinds of variables are derived based on the generalized variational principles. Compared to classical finite element method (FEM), the second generation wavelet-based multivariable finite element method (SGW-MFEM) combines the advantages of high approximation performance of the SGW method and independent solution of field functions of the MFEM. A multiscale algorithm for SGW-MFEM is presented to solve structural engineering problems. Numerical examples demonstrate the proposed method is a flexible and accurate method in static and vibration beam analysis.

RESEARCH ON THE WAVELET METHOD FOR THE IMPROVEMENT OF COMPUTATIONAL EFFICIENCY OF TWO DIMENSIONAL FLOW PROBLEMS (2차원 비정상 유동 해석 효율 향상을 위한 Wavelet 기법 응용 연구)

  • Kang, H.M.;Hong, S.W.;Jeong, J.H.;Kim, K.H.;Lee, D.H.;Lee, D.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03a
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    • pp.42-49
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    • 2008
  • A wavelet method is presented in order to improve the computational efficiency of two dimensional unsteady flow problems while maintaining the order of accuracy of conventional CFD schemes. First, by using the interpolating wavelet transformation including decomposition and thresholding, an adaptive dataset to a solution is constructed. Then, inviscid and viscous fluxes are calculated only at the points within an adaptive dataset, which enhances the computational efficiency. Second, thresholding step is modified to maintain the spatial and temporal accuracy of conventional CFD schemes automatically by selecting the threshold value between user-defined value and the magnitude of spatial or temporal truncation error. The wavelet method suggested in this study is successfully applied to various unsteady flow problems and it is shown that the computational efficiency is enhanced with maintaining the computational accuracy of CFD schemes.

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RESEARCH ON THE WAVELET METHOD FOR THE IMPROVEMENT OF COMPUTATIONAL EFFICIENCY OF TWO DIMENSIONAL FLOW PROBLEMS (2차원 비정상 유동 해석 효율 향상을 위한 Wavelet 기법 응용 연구)

  • Kang, H.M.;Hong, S.W.;Jeong, J.H.;Kim, K.H.;Lee, D.H.;Lee, D.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2008.10a
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    • pp.42-49
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    • 2008
  • A wavelet method is presented in order to improve the computational efficiency of two dimensional unsteady flow problems while maintaining the order of accuracy of conventional CFD schemes. First, by using the interpolating wavelet transformation including decomposition and thresholding, an adaptive dataset to a solution is constructed. Then, inviscid and viscous fluxes are calculated only at the points within an adaptive dataset, which enhances the computational efficiency. Second, thresholding step is modified to maintain the spatial and temporal accuracy of conventional CFD schemes automatically by selecting the threshold value between user-defined value and the magnitude of spatial or temporal truncation error. The wavelet method suggested in this study is successfully applied to various unsteady flow problems and it is shown that the computational efficiency is enhanced with maintaining the computational accuracy of CFD schemes.

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Structural health monitoring data reconstruction of a concrete cable-stayed bridge based on wavelet multi-resolution analysis and support vector machine

  • Ye, X.W.;Su, Y.H.;Xi, P.S.;Liu, H.
    • Computers and Concrete
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    • v.20 no.5
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    • pp.555-562
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    • 2017
  • The accuracy and integrity of stress data acquired by bridge heath monitoring system is of significant importance for bridge safety assessment. However, the missing and abnormal data are inevitably existed in a realistic monitoring system. This paper presents a data reconstruction approach for bridge heath monitoring based on the wavelet multi-resolution analysis and support vector machine (SVM). The proposed method has been applied for data imputation based on the recorded data by the structural health monitoring (SHM) system instrumented on a prestressed concrete cable-stayed bridge. The effectiveness and accuracy of the proposed wavelet-based SVM prediction method is examined by comparing with the traditional autoregression moving average (ARMA) method and SVM prediction method without wavelet multi-resolution analysis in accordance with the prediction errors. The data reconstruction analysis based on 5-day and 1-day continuous stress history data with obvious preternatural signals is performed to examine the effect of sample size on the accuracy of data reconstruction. The results indicate that the proposed data reconstruction approach based on wavelet multi-resolution analysis and SVM is an effective tool for missing data imputation or preternatural signal replacement, which can serve as a solid foundation for the purpose of accurately evaluating the safety of bridge structures.

Face recognition rate comparison using Principal Component Analysis in Wavelet compression image (Wavelet 압축 영상에서 PCA를 이용한 얼굴 인식률 비교)

  • 박장한;남궁재찬
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.41 no.5
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    • pp.33-40
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    • 2004
  • In this paper, we constructs face database by using wavelet comparison, and compare face recognition rate by using principle component analysis (Principal Component Analysis : PCA) algorithm. General face recognition method constructs database, and do face recognition by using normalized size. Proposed method changes image of normalized size (92${\times}$112) to 1 step, 2 step, 3 steps to wavelet compression and construct database. Input image did compression by wavelet and a face recognition experiment by PCA algorithm. As well as method that is proposed through an experiment reduces existing face image's information, the processing speed improved. Also, original image of proposed method showed recognition rate about 99.05%, 1 step 99.05%, 2 step 98.93%, 3 steps 98.54%, and showed that is possible to do face recognition constructing face database of large quantity.

Wavelet-Based Fuzzy Modeling Using a DNA Coding Method (DNA 코딩 기법을 이용한 웨이브렛 기반 퍼지 모델링)

  • Joo, Young-Hoon;Lee, Yeun-Woo;Yu, Jin-Young
    • Journal of the Korean Institute of Intelligent Systems
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    • v.13 no.6
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    • pp.737-742
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    • 2003
  • In this paper, we propose a new wavelet-based fuzzy modeling using a DNA coding method. Generally, it is well known that the DNA coding method is more diverse in the knowledge expression and better in the optimization performance than the genetic algorithm (GA) because it can encode more plentiful genetic information based on the biological DNA. The proposed method makes a fuzzy model by using the wavelet transform, in which coefficients are identified by the DNA coding method. Thus we can effectively get the fuzzy model of nonlinear system by using the advantages of both wavelet transform and DNA coding method. In order to demonstrate the superiority of the proposed method, it is compared with the GA.

Image Interpolation Using Phase-Shifted Wavelet Transforms (위상 보정된 웨이블릿 변환을 이용한 영상확대)

  • Kim, Sang-Soo;Eom, Il-Kyu;Kim, Yoo-Shin
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.387-390
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    • 2005
  • Parameter estimation for the probability model of wavelet coefficients is essential to the wavelet-domain interpolation. However, phase uncertainty, one well-known drawback of the orthogonal wavelet transforms, make it difficult to estimate parameters. In this paper, we exploit a phase shifting matrix in order to improve the accuracy of estimation. Nonlinear modeling to capture the interscale characteristics is also described. The experimental results show that the proposed method outperforms the previous wavelet-domain interpolation method as well as the conventional bicubic method.

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The Study of Sound Effect Improved Simulation though Wavelet analysis and Fourier transform (Wavelet 분석을 통한 시뮬레이션 음향 효과 개선에 관한 연구)

  • Kim, Young-Sik;Kim, Yong-Il;Bae, Myeong-Soo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.04a
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    • pp.960-962
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    • 2017
  • This thesis suggests method that How sound sources used to simulation that can be used to military training and education divide each frequency and each bandwidth filtering method. method for frequency dividing and denoising are suggested into Wavelet analysis. And We materialize authoring tool about filtering that design for wavelet job.