Skin detection is very challenging because of the differences in illumination, cameras characteristics, the range of skin colours due to different ethnicities and many other variations. New effective and accurate methodologies are developed for skin colour detection to easily identify human's skin colour threw databases which are specifically designed to assist research in the area of face recognition. One of these is the recently built SFA database that showed high accuracy for segmentation of face images. The approach described in this paper exploits skin and non-skin samples provided by SFA for skin segmentation on the basis of the well-known Euclidean and Manhattan distance metrics. Most importantly, the scheme proposed tries to segment facial colour images inside or outside SFA by means of skin samples belonging to SFA. Simulation results in both SFA and UTD colour face databases indicate that detection rates higher than 95% can be achieved with either measure.

Skin detection is very challenging because of the differences in illumination, cameras characteristics, the range of skin colours due to different ethnicities and many other variations. New effective and accurate methodologies are developed for skin colour detection to easily identify human's skin colour threw databases which are specifically designed to assist research in the area of face recognition. One of these is the recently built SFA database that showed high accuracy for segmentation of face images. The approach described in this paper exploits skin and non-skin samples provided by SFA for skin segmentation on the basis of the well-known Euclidean and Manhattan distance metrics. Most importantly, the scheme proposed tries to segment facial colour images inside or outside SFA by means of skin samples belonging to SFA. Simulation results in both SFA and UTD colour face databases indicate that detection rates higher than 95% can be achieved with either measure.

In this paper, the leaky acoustic microwaves (LAW) in a piezoelectric substrate (Lithium Niobate LiNbO3 Cut Y-X) were studied. The main method for this research was classification using a probabilistic neural network (PNN).The originality of this method is in the accurate values it provides. In our case, this technique was helpful in identifying undetectable waves, which are difficult to identify by classical methods. Moreover, all the values of the real part and the imaginary part of the coefficient attenuation with the acoustic velocity were classified in order to build a model from which we could easily note the Leaky waves. Accurate values of the coefficient attenuation and acoustic velocity for Leaky waves were obtained. Hence, in this study, the focus was on the interesting modeling and realization of acoustic microwave devices (radiating structures) based on the propagation of acoustic microwaves

Laser communication between satellites in the constellation and from the satellites to ground stations offers a gigantic data rate for the users. This principal advantage drives telecom companies to develop this technology to use it like a carrier signal, the most disadvantage of this technology is the need to very complicated pointing systems between the transmitter and the receiver due to a very small beam divergence, continually moving of satellites in orbits and the distance between the satellites (tens of thousands of kilometers). The laser beam suffers continuously from several factors like atmospheric turbulences, internal and external vibrations. All these factors lead to an increase in the bit errors rate and cause degradation in the communication quality. This paper deals with a new method of modelisation of external effects in transmission of signal light from a ground station to the satellite through atmospheric disturbances. Indeed, an in-depth investigation, of the influences of satellite vibrationsinlaser signal transmission between satellites constellation, has been conducted by studying the effect of the intensity of vibrations on the optical signal amplitude. Some solutions are proposed to improve the efficiency of optical satellites communications.

This paper presents an efficient method for recovery of SIMS signals from strongly noised blurred discrete data. This technique is based on Tikhonov-Miller regularization where a priori model of solution is included. The latter is a denoisy signal obtained using the Kalman filter. This is an interesting estimation method, but it can only be used when the system is described precisely. By comparing the results of the proposed technique with those of the literature, our algorithm gives the best results without artifacts and oscillations related to noise and significant improvement of the depth resolution. While, the gain in FWHM is less improved than those obtained by the wavelet technique. Therefore, this new algorithm can push the limits of SIMS measurements towards its ultimate resolution.

In this paper, we propose a new numerical method for acoustics microwaves detection of an acoustics microwaves signal during the propagation of acoustics microwaves in a piezoelectric substrate zinc oxide (ZnO). We have used support vector machines (SVMs), the originality of this method is the accurate values that provides this technique help to identify undetectable waves that we can not identify with the classical methods. We classify all the values of the real part and the imaginary part of the coefficient attenuation with the acoustic velocity in order to build a model from which we note the types of microwaves acoustics (bulk waves or surface waves or leaky waves). We obtain accurate values for each of the coefficient attenuation and acoustic velocity. This study will be very interesting in modelling and realisation of acoustics microwaves devices (ultrasound, radiating structures, filter SAW…) based on the propagation of acoustics microwaves.

Our work is mainly about detecting acoustics microwaves in the type of BAW (Bulk acoustic waves), where we compared between Lithium Niobate (LiNbO3) and Lithium Tantalate (LiTaO3) ,during the propagation of acoustic microwaves in a piezoelectric substrate. In this paper, We have used the classification by Probabilistic Neural Network (PNN) as a means of numerical analysis in which we classify all the values of the real part and the imaginary part of the coefficient attenuation with the acoustic velocity for conclude whichever is the best in utilization for generating bulk acoustic waves.This study will be very interesting in modeling and realization of acoustic microwaves devices (ultrasound) based on the propagation of acoustic microwaves.

In this paper, we present a rigorous full-wave analysis able to estimate exactly the resonant characteristics of stacked high T_c superconducting circular disk microstrip antenna. The superconducting patches are assumed to be embedded in a multilayered substrate containing isotropic and/or uniaxial anisotropic materials (the analysis is valid for an arbitrary number of layers). London’s equations and the two-fluid model of Gorter and Casimir are used in the calculation of the complex surface impedance of the superconducting circular disks. Numerical results are presented for a single layer structure as well as for two stacked circular disks fabricated on a double-layered substrate.

The resonant frequencies and bandwidths of the inverted rectangular patch over anisotropic substrates are investigated in this paper. A rigorous analysis is performed using dyadic Green’s function formulation in the vector Fourier transform domain. The Galerkin’s technic is then used in the resolution of the integral equation; the complex resonance frequencies for the TM01 mode are studied with sinusoidal basis functions. The numerical results obtained are compared with previously published numerical results computed by means of the electromagnetic simulator “IE3D software”. Good agreement is found in all cases among all sets of results. For an isotropic substrate, it is confirmed that the bandwidth decreases with increasing of air-gap layer for high permittivity and low thickness of the substrate. Also, we show that the resonant frequencies and bandwidths are highly dependent on the permittivity variations alongside the optical axis. Other theoretical results attained display that the resonant frequencies downtrend monotonically with increasing substrate thickness, the diminution being larger for the uniaxial anisotropy of the substrate. Finally, numerical results for the effects of uniaxial anisotropy in the substrate on the radiation of the inverted rectangular microstrip structure are also presented.

A complete parametric study of stacked rectangular microstrip patches printed on non-magnetic isotropic substrate is performed. The numerical results are obtained by applying the method of moments to the electric field integral equations. Detailed closed-form expressions of Green's functions are presented. The new results found indicate that, the lower resonant frequency is mainly determined by the patch etched on the thicker layer. The layer having the higher permittivity defines which resonance is mainly determined by the bottom patch, either the upper resonance if the upper layer has the higher permittivity, or the lower resonance in opposite case. All these results offer better understanding and thus a better control of the dual-band operating of the microstrip antenna. Therefore, a proper choice of the antenna parameters becomes possible in order to obtain the desired functional characteristics.

Spectral domain formulation is provided for the analysis of rectangular stacked patches printed on a substrate characterized by dielectric and magnetic uniaxial anisotropy. Detailed analytical expressions of the dyadic Green’s functions are derived. Galerkin’s procedure is applied to solve the electric field integral equations, and the resonance characteristics are determined by solving the characteristic equation. Numerical results show that the influence of the magnetic anisotropy on the resonant frequencies is highly dependent on the permeability of the medium, where for a non-magnetic medium, the impact of the existing anisotropy was found negligible. However, for a magnetic medium, the anisotropy has a large impact on the resonant frequencies. Moreover, the influence of each of the components of the permeability tensor has been also reported.

This work is mainly on the detection of the bulk acoustic waves (BAWs), where we have compared two Lithium Niobate cuts (Y-Z and Y-X), during the propagation of the acoustic microwaves in the piezoelectric LiNbO3-substrate. In this paper, we have used the classification by Probabilistic Neural Network (PNN) as a tool for numerical analysis in which we classify all the values of the real and imaginary parts of the attenuation coefficient for the propagation velocity. This analysis can allow us to demonstrate the best possibility in utilization for the BAW generation. This study will be very interesting in modeling and realization of acoustic wave devices (ultrasound) based on the propagation of acoustic microwaves.

In this paper, an electromagnetic approach based on cavity model in conjunction with electromagnetic knowledge was developed. The cavity model combined with London’s equations and the Gorter-Casimir two-fluid model has been improved to investigate the resonant characteristics of high Tc superconducting circular microstrip patch in the case where the patch is printed on uniaxially anisotropic substrate materials.  Merits of our extended model include low computational cost and mathematical simplify. The numerical simulation of this modeling shows excellent agreement with experimental results available in the literature. Finally, numerical results for the dielectric anisotropic substrates effects on the operating frequencies for the case of superconducting circular patch are also presented.

In this paper, the effects of both anisotropies in the substrate and superstrate loading on the resonant frequency and bandwidth of high-Tc superconducting circular microstrip patch in a substrate-superstrate configuration are investigated. A rigorous analysis is performed using a dyadic Galerkin's method in the vector Hankel transform domain. Galerkin's procedure is employed in the spectral domain where the TM and TE modes of the cylindrical cavity with magnetic side walls are used in the expansion of the disk current. The effect of the superconductivity of the patch is taken into account using the concept of the complex resistive boundary condition. London's equations and the two-fluid model of Gorter and Casimir are used in the calculation of the complex surface impedance of the superconducting circular disc. The accuracy of the analysis is tested by comparing the computed results with previously published data for several anisotropic substrate-superstrate materials. Good agreement is found among all sets of results. The numerical results obtained show that important errors can be made in the computation of the resonant frequencies and bandwidths of the superconducting resonators when substrate dielectric anisotropy, and/or superstrate anisotropy are ignored. Other theoretical results obtained show that the superconducting circular microstrip patch on anisotropic substrate-superstrate with properly selected permittivity values along the optical and the non-optical axes combined with optimally chosen structural parameters is more advantageous than the one on isotropic substrate-superstrate by exhibiting wider bandwidth characteristic.

In this paper, an efficient full-wave analysis of a circular microstrip patch printed on suspended and composite substrates is performed using a dyadic Green’s function formulation. Galerkin’s technique is used in the resolution of the integral equation of the electric field. The TM set of modes issued, from the magnetic wall cavity model, are used to expand the unknown currents on the circular patch. The radiation patterns are expressed regarding the transforms of the currents. The convergence of the method is proven by calculating the resonant frequencies, half-power bandwidths, and quality factors for several configurations. The computed results are found to be in excellent agreement with those observed in the literature. The numerical results obtained show that the bandwidth increases with the increase in the thickness of the suspended or composite substrates, especially for low permittivity of the second layer. Also, it is demonstrated that the resonant frequencies of the circular microstrip patch on suspended and composite substrates can be adjusted to obtain the maximum operating frequency of the antenna. Finally, the effect of the presence of the second layer under the circular patch on the radiation patterns is also investigated.

The back propagation (BP) algorithm has been very successful in training multilayer perceptron-based equalisers; despite its success BP convergence is still too slow. Within this paper we present a new approach to enhance the training efficiency of the multilayer perceptron-based equaliser (MLPE). Our approach consists on modifying the conventional back propagation algorithm, through creating an adaptive nonlinearity in the activation function. Experiment results evaluates the performance of the MLPE trained using the conventional BP and the improved back propagation with adaptive gain (IBPAG). Due to the adaptability of the activation function gain the nonlinear capacity and flexibility of the MLP is enhanced significantly. Therefore, the convergence properties of the proposed algorithm are more improved compared to the BP. The proposed algorithm achieves the best performance in the entire simulation experiments.