Electronique

Nombre total de résultats :519
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Video Processing Software-based Pipeline Endoscopic Inspection

Nadia MHAMDA, Nafaa Nacereddine, Aissa Boulmerka  (2018)
Article de conférence

Currently, all the codes and the standards of the fluids transport industries require rigorous pipeline inspection, in order to detect all defects and anomalies and avoid leaks and failures. For this reason, a team within the division of Signal Processing and Imagery had as mission to develop an endoscope which can replace the operator inspection inside the pipeline and improve its quality and diagnostic. This endoscope named 'Pipe Explorer' is controlled by FPGA microcontrollers, and is equipped with a camera. While moving inside the pipe, the camera records a video on the memory card. In this way and in order to offer a practical tool to the operator, we have developed graphical software based on processing techniques of the stored video consisting in video preprocessing and segmentation. At the end of this processing, we obtain a video result on which appears the analysis and the interpretation of the original video to give an internal pipe quality diagnosis. The results shows all the defective areas such as corrosion which are stained with {green, blue, red} color according to its degree of severity and the risk of harmfulness on the inspected pipeline. Voir les détails

Mots clés : Pipeline inspection, endoscopy, video processing, video segmentation, corrosion.

Study and modelling of a microwave sensor tocharacterize a dielectric materials and for CNDapplications

Z.GUEZOUI, M.amir, H.Amar  (2018)
Article de conférence

Non-destructive testing is a science of evaluationvarious properties of materials, without compromising itsusefulness and use. These properties can be physical, chemical,mechanical or geometrical. There are several techniques of nondestructive testing such as: acoustic emission, penetrate testing,eddy current, ultrasound and radiography, ... . However, each ofthese methods has certain limitations and disadvantages. Sincethe 1970s, some researchers have tried to use microwavetechniques to detect possible surface cracks in metal components,volumic cracks in dielectric materials or to characterize adielectric material.The objective of this article is to present a method ofcharacterization of dielectric materials, by modeling a microwavesensor. A change in the resonant frequency of the microwavesensor resulting from a change in its effective dielectric constantis considered as an index to define the dielectric constant of thesample. This work was devoted to study, modelling andrealization of a micro strip structure by the method of moments,later this structure will be simulated by a numerical modellingsoftware HFSS (High-Frequency Structure Simulator) to confirmthe results and validate the model. Voir les détails

Mots clés : Non-Destructive testing, Microwave Techniques, HFSS, Microwave Sensor, Dielectric Constant, Micro strip Modelling, moment method

Performance of some Variational ImplicitDeformable Models on Segmenting OpticalMicroscopy Images

Y. Boutiche, N. Cheteh, N. Ramou  (2018)
Article de conférence

Industrial micrographs are used to evaluate a steelsor alloys. This assessment consists of visualizing and describingthe basic element (at the nanoscale) constituting the material.The information provided by the micrographic images needto be highlighted by image processing methods. In this paperthe performance of some region-based variational models arepresented. Such study allows to choose best models that give themore accuracy segmentation in less processing time. Voir les détails

Mots clés : Material microstructures, Microscopy images, segmentation, deformable models, region-based active contours

Design of Sobel Filter in VHDL

Mazouz Nezhate, Bouhouche Salah, Ziad Mostepha, DRAI Redouane  (2018)
Article de conférence

In order to automate the quality control process of pipe’s welding joint, we present in this paper a new design of an embedded computer vision system, which is based on a camera, controlled by an FPGA platform (Zynq-7000) for acquisition and image processing on the same FPGA circuit. A VHDL implementation of Sobel Edge Detection Algorithm is proposed. The obtained results were validated with those obtained by MATLAB.This will allow us to develop other tools more powerful and more robust. Voir les détails

Mots clés : Quality control, pipe welds, FPGA, Sobel, VHDL

Comparative study between EKF and Geometrical methods for theAcoustic Emission source localization.

E.Y. DRIS, R. Drai, M. Bentahar, D. Berkani, A. BENAMMAR  (2018)
Article de conférence

The purpose of this paper is to optimize and apply probabilistic methods and compare the obtained results to geometric method for locating acoustic emission (AE) source in a plate-like structure. The time of arrival (TOA) of the AE waves in each sensor taking into account the uncertainties, was determined by the continuous wavelet transform (CWT). Then the group wave's velocity was calculated by Monte Carlo simulation. As a probabilistic method, the extended Kalman filter (EKF) is used to iteratively estimate the location of AE sources. Experimental results have shown that the probabilistic method estimates thelocation of the pencil lead break better than the geometric method.Experimental tests were performed on a copper plate to validate the comparison of the two approaches performances. Voir les détails

Mots clés : Acoustic Emission (AE), Time of arrival (TOA), Continuous Wavelet Transform (CWT), Monte Carlo simulation, Geometrical method, Extended Kalman Filter (EKF)

Vibration for detection and diagnosis bearing faults using adaptive neurofuzzy inference system

Djamila Bouneb, Tahar Bahi, Hichem MERABET  (2018)
Publication

The fault diagnosis of electrical machines is a primordial and necessary task in industry. Thefailure is unbearable because it causes, incontestably, decrease in production and increases costrepair. Induction motors are the most important equipment in industry, where reliability andsafe operation is desirable, for maintenance, such as detection, and diagnosis of mechanical andelectrical defects of electric drives. The several techniques are adopted and frequency analysis isthe most widely used. Artificial intelligence techniques was gained popularity last decay’s innumerous applications. The presented results show the detected and diagnosed, of the bearingfaults of the induction motor, based on Adaptive Neuro-Fuzzy Inference System. The vibrationsanalysis of the induction machine using the Artificial Intelligence Techniques, combining neuralnetworks and fuzzy logic has been applied successfully. The designed ANFIS network showsabout 99% accurate results as validated by Mat lab / Simulink simulation Voir les détails

Mots clés : diagnosis, fault, vibration, bearing

Optoelectronic properties of the new quaternary chalcogenides Zn2CuInTe4 & Cd2CuInTe4: ab-initio study.

M. I. ZIANE, M. TABLAOUI, A. KHELFANE, M. HADJAB  (2018)
Publication

In order to exploit the fundamental properties of the new tellurides quaternary diamond-like structure Zn2CuInTe4 and Cd2CuInTe4, first principles investigation in the frameworkof the Full-Potential LAPW scheme have been carried out for that purpose. We used theWu and Cohen generalized gradient approximation (GGA-WC) to calculate the optimizedstructure that corresponds to the global minima of the energy. Enthalpy of formation showsthat the most stable structures are the relaxed ones. The EV-GGA and the TB-mBJ approx-imations were also used for electronic and optical properties. The equilibrium electronicparameters found are in good agreement with the previous results. The real and thecient, theopt imaginary parts of the dielectric function, the refractive index, the extinction coeffiicalconductivity, the absorption coefficient, the loss function and the reflectivity are reviewedin the large spectral range of photon energy. The present study demonstrates a variety ofnovel electronic and optical properties, which make these compounds highly promising foroptoelectronic materials. Voir les détails

Mots clés : DFT, Quaternary tellurides, Enthalpy of formation, band gap, Absorption coefficient

First principles investigation of optoelectronic properties ofZnXP2 (X = Si, Ge) lattice matched with silicon for tandemsolar cells applications using the mBJ exchange potential

H. BANNACER, A. BOUKORTT, S. MESKINE, M. HADJAB, M. I. ZIANE, A. ZAOUI  (2018)
Publication

II-IV-V2 materials are attractive compounds for optoelectronic, photonic and photovoltaicapplications due to their valuable ternary chemistry. A primary technological challengein photovoltaics is to find and develop a lattice matched efficient material to be usedin combination with silicon for tandem solar cells. ZnSiP2 and ZnGeP2 chalcopyrites arepromising semiconductors that could satisfy these criteria. Particularly, ZnSiP2 is known tohave bandgap energy of∼2 eV and a lattice mismatch with silicon of 0.5%. In this work, thefirst principle calculations have been performed to investigate the structural, electronic andoptical properties of ZnSiP2 and ZnGeP2 in chalcopyrite structure within the Full Potential-Linearized Augmented Plane Wave (FP-LAPW) method based on the Density FunctionalTheory (DFT) as implemented in WIEN2K code. The local Density approximation (LDA) ofPerdew and Wang was used as exchange-correlation potential to calculate the structuralproprieties. Furthermore, the recently modified Becke-Johnson (mBJ) functional of Tranand Blaha was also employed to compute the electronic and optical properties in order toget best values of the band gap energy and some better degree of precision. The complexdielectric function, the complex refractive index, reflectivity, absorption coefficient, and theoptical conductivity were calculated to illustrate the linear optical properties of both compoundsZnSiP2 and ZnGeP2. At last, the obtained results indicate that ZnSiP2 and ZnGeP2are attractive materials in optoelectronic devices especially as a lattice matched materialwith silicon for tandem solar cells applications. Voir les détails

Mots clés : FP-LAPW, mBJ, Chalcopyrite, Electronic band structure, Linear optical properties

Optical study of cubic, and orthorhombic structures of XCaCl3 (X = K, Rb) compounds: Comparative Ab initio calculations

A.HADJ LARBI, S. Hiadsi, M. HADJAB, M. A. SAEED  (2018)
Publication

The study predicts the optical properties of cubic and orthorhombic structures of XCaCl3 (X = K, Rb) perovskite compounds through electronic band structure computation within the framework of density functional theory (DFT). The ground state functions are computed employing full potential linearized augmented plane wave (FP-LAPW) method. Improved band gap values and the electronic as well as optical properties were calculated by Tran and Blaha modified Becke–Johnson (mBJ) functional. The studied compounds’ density of states reveals that Cl-p states dominate the valence band. To understand the optical properties, and predicting the optically isotropic nature of these materials, the real and imaginary parts of dielectric function, refractive index, absorption coefficient, and energy loss spectra are plotted. The present study shows a great potential utilization in ceramic scintillators. Voir les détails

Mots clés : DFT, FP-LAPW, Perovskites, Optical parameters, Scintillators

Structural, electronic and optical properties for chalcopyrite semiconducting materials: ab-initio computational study

Moufdi Hadjab, Miloud IBRIR, Smail BERRAH, Hamza ABID, Mohammad Alam Saeed  (2018)
Publication

Investigation of the physical properties of chalcopyrite materials using ab-initio methods have been carried out to simulate a new structure of thin-films photovoltaic cells with high conversion efficiency. The Density Functional Theory calculations have been performed using Wien2k computational package by employing the full-potential linearized augmented plane wave method. Structural and electronic properties of chalcopyrite semiconducting material Copper–Indium–Gallium–Selenium i.e. CuIn1-xGaxSe2 have been investigated using local density approximation for the exchange-correlation potential. The electronic structures and linear optical properties have been studied using both the semi-local Becke-Johnson potential and its modified form i.e. mBJ and TB-mBJ. Computational results are in good agreement with those acquired experimentally. The viability of alloys in realization of ultra-thin-film based (CIGS) solar cells with high performance has been proposed after simulation and analysis study using one of solar cell simulation tools. The studied material exhibits capability to become a promising candidate for fabrication of optoelectronic and photovoltaic devices. Voir les détails

Mots clés : Chalcopyrite, FP-LAPW, optical properties, Thin-films solar cells, wien2k