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Browsing Journal Articles by Author "Ahmed, Bentoumi"

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    Parameter Estimation of Rayleigh-Generalized Gamma Mixture Model
    (Université de M'sila, 2019-12) Ahmed, Bentoumi; Amar, Mezache; Houcine, Oudira
    The estimation problem of three parameters Rayleigh-Generalized Gamma Mixture (R-GG) radar clutter model is addressed in this paper. Expressions of integer order moments, non-integer order moments and logarithmic moments are presented in such away the scale parameter of the R-GG probability density function (PDF) is eliminated and a two-dimensional estimators labeled HOME, NIOME and [zlog(z)] methods are obtained. Due to the presence of gamma function with fractional variables, these estimators cannot be given in closed forms. The fitness function for each estimator is given as a sum of squared errors of nonlinear equations. Using a numerical routine based upon the simplex search algorithm, the proposed methods were tested firstly on artificial data. Tail fitting of the R-GG model and the standard K-distribution (i.e., special case of the R-GG) is assessed against recorded radar data. The accuracy of the R-GG model and the proposed estimation methods is satisfactory, with the most accuracy of the [zlog(z)] method.
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    Welsh DSP Estimate and EMD Applied to Leak Detection in a Water Distribution Pipeline
    (Université de M'sila, 2019-12) Bentoumi, Miloud; Bakhti, Haddi; Ahmed, Bentoumi
    This work deals to introduce a new idea inspired from the empirical mode decomposition (EMD) technique in order to detect a leak in water distribution networks (WDN). Welsh’s power spectral density (WPSDE) is used to locate the frequency band in which leaks occur. Leaks produce acoustic and vibration signals propagating along the pipeline, which have nonlinear and non-stationary characteristics. Hydraulic pressure, the nature and diameter of the pipe as well as the size of the leak are considered as sources acting on the leakage signals. The analysis of such leakage signals using conventional methods is limited by the choice of the narrow bands and cause therefore the loss of useful information. EMD is a technique that allows the decomposition of a signal in the time domain as stationary oscillatory signals called intrinsic mode functions (IMFs), which can be processed separately. Experiments were carried out to verify the validity of the proposed method. That shows its best performances in detecting leaks. For the localization, we applied the Short-Time Fourier Transform (STFT) technique that has the potential to locate leaks at greater distances from a measurement point and proved its efficiency