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  • Open Access

    ARTICLE

    Spectral and wavelet analysis in the wake of an airfoil with Gurney flap

    Pablo Giacopinelli1, Ana Scarabino1, Federico Bacchi1, Juan Sebastián Delnero2

    Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería, Vol.39, No.1, pp. 1-7, 2023, DOI:10.23967/j.rimni.2023.03.001 - 15 March 2023

    Abstract In this work we identify the coherent vortices in the leeward wake of an HQ 17 airfoil with a Gurney flap. This high-lift device consists of a small plate perpendicular to the airfoil, at or near the trailing edge, with a height H of the order from 1% to 4% of the chord. The overall effect is to produce a significant increase in lift, together with a relatively minor increase in airfoil drag. Its geometry generates vortex shedding of spatial scale H, which modulates the wake and thus influence the global configuration of the flow. A… More >

  • Open Access

    ARTICLE

    An Efficient Numerical Scheme for Biological Models in the Frame of Bernoulli Wavelets

    Fei Li1, Haci Mehmet Baskonus2,*, S. Kumbinarasaiah3, G. Manohara3, Wei Gao4, Esin Ilhan5

    CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.3, pp. 2381-2408, 2023, DOI:10.32604/cmes.2023.028069 - 03 August 2023

    Abstract This article considers three types of biological systems: the dengue fever disease model, the COVID-19 virus model, and the transmission of Tuberculosis model. The new technique of creating the integration matrix for the Bernoulli wavelets is applied. Also, the novel method proposed in this paper is called the Bernoulli wavelet collocation scheme (BWCM). All three models are in the form system of coupled ordinary differential equations without an exact solution. These systems are converted into a system of algebraic equations using the Bernoulli wavelet collocation scheme. The numerical wave distributions of these governing models are More >

  • Open Access

    ARTICLE

    Meta-Heuristic Optimized Hybrid Wavelet Features for Arrhythmia Classification

    S. R. Deepa1, M. Subramoniam2,*, R. Swarnalatha3, S. Poornapushpakala2, S. Barani2

    Intelligent Automation & Soft Computing, Vol.37, No.1, pp. 745-761, 2023, DOI:10.32604/iasc.2023.034211 - 29 April 2023

    Abstract The non-invasive evaluation of the heart through EectroCardioGraphy (ECG) has played a key role in detecting heart disease. The analysis of ECG signals requires years of learning and experience to interpret and extract useful information from them. Thus, a computerized system is needed to classify ECG signals with more accurate results effectively. Abnormal heart rhythms are called arrhythmias and cause sudden cardiac deaths. In this work, a Computerized Abnormal Heart Rhythms Detection (CAHRD) system is developed using ECG signals. It consists of four stages; preprocessing, feature extraction, feature optimization and classifier. At first, Pan and… More >

  • Open Access

    ARTICLE

    ANALYSIS OF LAMINAR BOUNDARY-LAYER FLOW OVER A MOVING WEDGE USING A UNIFORM HAAR WAVELET METHOD

    Harinakshi Karkeraa , Nagaraj N. Katagia,† , Ramesh B. Kudenattib

    Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-10, 2022, DOI:10.5098/hmt.18.41

    Abstract In this paper, we study the characteristics of laminar boundary-layer flow of a viscous incompressible fluid over a moving wedge. The transformed boundary-layer equation given by the Falkner-Skan equation is solved by an efficient easy-to-use approximate method based on uniform Haar wavelets in conjunction with quasilinearization and collocation approach. The residual and error estimates are computed to confirm the validity of the obtained results. A meaningful comparison between the present solutions with existing numerical results in the literature is carried out to highlight the benefits and efficiency of proposed method. Furthermore, the influence of variable More >

  • Open Access

    ARTICLE

    An Automated Brain Image Analysis System for Brain Cancer using Shearlets

    R. Muthaiyan1,*, Dr M. Malleswaran2

    Computer Systems Science and Engineering, Vol.40, No.1, pp. 299-312, 2022, DOI:10.32604/csse.2022.018034 - 26 August 2021

    Abstract In this paper, an Automated Brain Image Analysis (ABIA) system that classifies the Magnetic Resonance Imaging (MRI) of human brain is presented. The classification of MRI images into normal or low grade or high grade plays a vital role for the early diagnosis. The Non-Subsampled Shearlet Transform (NSST) that captures more visual information than conventional wavelet transforms is employed for feature extraction. As the feature space of NSST is very high, a statistical t-test is applied to select the dominant directional sub-bands at each level of NSST decomposition based on sub-band energies. A combination of… More >

  • Open Access

    ARTICLE

    Medical Image Compression Based on Wavelets with Particle Swarm Optimization

    Monagi H. Alkinani1,*, E. A. Zanaty2, Sherif M. Ibrahim3

    CMC-Computers, Materials & Continua, Vol.67, No.2, pp. 1577-1593, 2021, DOI:10.32604/cmc.2021.014803 - 05 February 2021

    Abstract This paper presents a novel method utilizing wavelets with particle swarm optimization (PSO) for medical image compression. Our method utilizes PSO to overcome the wavelets discontinuity which occurs when compressing images using thresholding. It transfers images into subband details and approximations using a modified Haar wavelet (MHW), and then applies a threshold. PSO is applied for selecting a particle assigned to the threshold values for the subbands. Nine positions assigned to particles values are used to represent population. Every particle updates its position depending on the global best position (gbest) (for all details subband) and More >

  • Open Access

    ARTICLE

    Solving the Nonlinear Variable Order Fractional Differential Equations by Using Euler Wavelets

    Yanxin Wang1, *, Li Zhu1, Zhi Wang1

    CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.2, pp. 339-350, 2019, DOI:10.31614/cmes.2019.04575

    Abstract An Euler wavelets method is proposed to solve a class of nonlinear variable order fractional differential equations in this paper. The properties of Euler wavelets and their operational matrix together with a family of piecewise functions are first presented. Then they are utilized to reduce the problem to the solution of a nonlinear system of algebraic equations. And the convergence of the Euler wavelets basis is given. The method is computationally attractive and some numerical examples are provided to illustrate its high accuracy. More >

  • Open Access

    ARTICLE

    Numerical Solutions of Fractional System of Partial Differential Equations By Haar Wavelets

    F. Bulut1,2, Ö. Oruç3, A. Esen3

    CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.4, pp. 263-284, 2015, DOI:10.3970/cmes.2015.108.263

    Abstract In this paper, time fractional one dimensional coupled KdV and coupled modified KdV equations are solved numerically by Haar wavelet method. Proposed method is new in the sense that it doesn’t use fractional order Haar operational matrices. In the proposed method L1 discretization formula is used for time discretization where fractional derivatives are Caputo derivative and spatial discretization is made by Haar wavelets. L2 and L error norms for various initial and boundary conditions are used for testing accuracy of the proposed method when exact solutions are known. Numerical results which produced by the proposed method for More >

  • Open Access

    ARTICLE

    A Finite Wavelet Domain Method for the Rapid Analysis of Transient Dynamic Response in Rods and Beams

    C.V. Nastos, T.C. Theodosiou, C.S. Rekatsinas, D.A. Saravanos1

    CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.5, pp. 379-409, 2015, DOI:10.3970/cmes.2015.107.379

    Abstract A computationally efficient numerical method is developed for the prediction of transient response in orthotropic rod and beam structures. The method takes advantage of the outstanding properties of compactly supported Daubechies wavelet scaling functions for the spatial approximation of displacements in a finite domain of the structure, hence is termed Finite Wavelet Domain (FWD) method. The basic principles and advantages of the method are presented and the discretization of the equations of motion is formulated for one-dimensional structures. Numerical results for the simulation of propagating guided waves in rods and strips are presented and compared More >

  • Open Access

    ARTICLE

    New Spectral Solutions of Multi-Term Fractional-Order Initial Value ProblemsWith Error Analysis

    W. M. Abd- Elhameed1,2, Y. H. Youssri2

    CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.5, pp. 375-398, 2015, DOI:10.3970/cmes.2015.105.375

    Abstract In this paper, a new spectral algorithm for solving linear and nonlinear fractional-order initial value problems is established. The key idea for obtaining the suggested spectral numerical solutions for these equations is actually based on utilizing the ultraspherical wavelets along with applying the collocation method to reduce the fractional differential equation with its initial conditions into a system of linear or nonlinear algebraic equations in the unknown expansion coefficients. The convergence and error analysis of the suggested ultraspherical wavelets expansion are carefully discussed. For the sake of testing the proposed algorithm, some numerical examples are More >

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