this paper concentrates on a new procedure which experimentally recognises gears and bearings faults of a typical gearbox system using a least square support vector machine (lssvm). two wavelet selection criteria maximum energy to shannon entropy ratio and maximum relative wavelet energy are used and compared to select an appropriate wavelet for feature extraction. the fault diagnosis method co...

this paper concentrates on a new procedure which experimentally recognises gears and bearings faults of a typical gearbox system using a least square support vector machine (lssvm). two wavelet selection criteria maximum energy to shannon entropy ratio and maximum relative wavelet energy are used and compared to select an appropriate wavelet for feature extraction. the fault diagnosis method co...

The solar activity is asymmetric in both hemispheres almost all cycles. This asymmetry observed cycle amplitude and period. We have used about 90~years of sunspot-area data from the Kodaikanal Solar Observatory to study North--South sunspot activity. monthly mean showed northern hemisphere dominated Cycles 16, 19, 20, southern 18, 22, 23. 13-months smoothed indicated that Cycle 17 21, equal amp...

in exploration seismology quality factor is widely used as a seismic attribute to identify anomalies related to attenuation, especially those caused by hydrocarbon. previous studies have indicated that seismic energy loss known as attenuation is greater for high frequency components of seismic data compared to the low frequency components. here the continuous wavelet transform is used to study ...

In recent years, there has been greater attempt to find numerical solutions of differential equations using wavelet's methods. The following method is based on vector forms of Haar-wavelet functions. In this paper, we will introduce one dimensional Haar-wavelet functions and the Haar-wavelet operational matrices of the fractional order integration. Also the Haar-wavelet operational matrices of ...

this paper presents a rational haar wavelet operational method for solving the inverse laplace transform problemand improves inherent errors from irrational haar wavelet. the approach is thus straightforward, rather simple andsuitable for computer programming. we define that $p$ is the operational matrix for integration of the orthogonalhaar wavelet. simultaneously, simplify the formulaes of li...

Regularization methods improve the stability of ill-posed inverse problems by introducing some a priori characteristics for solution such as smoothness or sharpness. In this contribution, we propose multidimensional, scale-dependent wavelet-based L1-regularization term to cure ill-posedness airborne (time-domain) electromagnetic induction problem. The regularization is flexible, it can recover ...

Atmospheric turbulence has significant influences on both the trajectories and strengths of wake vortices. In this paper, a quasi-wavelet method is used to generate a random atmospheric turbulence field based on the von Kármán spectrum, in which atmospheric turbulence is represented by groups of random eddies. An inviscid wake vortex system, out-of-ground effect or in-ground effect, is immersed...

This study investigates the applicability of time reversal concept in modern acoustics to structural health monitoring. A time reversal method has been adapted to guided-wave propagation to improve the detectability of local defects in composite plate structures. Specifically, wavelet-based signal processing techniques have been developed to enhance the time reversibility of Lamb wave in thin c...