• Aucun résultat trouvé

Deconvolution of closer ultrasonic backscattered echo signals from composite materials

N/A
N/A
Info
Télécharger
Protected

Academic year: 2021

Partager "Deconvolution of closer ultrasonic backscattered echo signals from composite materials"

Copied!
1
0
0

Chargement.... (Voir le texte intégral maintenant)

Texte intégral

(1)

International Congress on Ultrasonics (ICU2007) 2007

Deconvolution of closer ultrasonic backscattered echo signals from composite materials

Abdessalem BENAMMAR, Redouane DRAI, Ahmed KECHIDA, Abderrezak GUESSOUM

Abstract : In this paper, we present an approach of deconvolution problem from the estimation of superimposed signals based on the Expectation Maximization Algorithm (EM algorithm) and Maximum Likelihood Estimation. The idea is to decompose the observed data into their signal components and then to estimate separately the parameters of each component signal. This algorithm iterates back and forth using the current estimated parameter in order to decompose the observed data and thus to increase the likelihood of the next estimated parameters. We initially apply this method to simulated signals with additional structural noise.

These signals contain several echo defects, closer between them. This stage permits to see the robustness of the developed algorithm. Thereafter, we validate all simulated results by experimental results obtained on composite material with and without delamination defects.

Keywords : Ultrasonic NDE, composite materials, Deconvolution, EM algorithm

Centre de Recherche en Technologies Industrielles - CRTI - www.crti.dz

Powered by TCPDF (www.tcpdf.org)

Références

Télécharger maintenant ( PDF - 1 Page - 7.82 KB )

Documents relatifs

Maximum likelihood estimation from fuzzy data using the EM algorithm

This approach, called the Fuzzy EM (FEM) method, is illustrated using three classical problems: normal mean and variance estimation from a fuzzy sample, multiple linear regression

Cosmological parameter estimation with the Planck satellite data : from the construction of a likelihood to neutrino properties

The characterisation of the likelihood is completed in chapter 6 with the description of the Planck large scale data and the external datasets that are used in the estimation of

Discharge and suspended sediment flux estimated along the mainstream of the Amazon and the Madeira Rivers (from in situ and MODIS Satellite Data)

Discharge and suspended sediment flux estimated along the mainstream of the Amazon and the Madeira Rivers (from in situ and MODIS Satellite Data).. International Journal of

Committee Assignments as Side Payments: The Interplay of Leadership and Committee Development in the Era of Good Feelings

(4) Select committee on Missouri, which reports a simple bill to admit Missouri; bill consideration postponed, under motion of Taylor, so that a select committee could hammer out

Le Crétacé Supérieur - Paléogène du Bassin Compressif Nord-Pyrénéen (Bassin de l'Adour). Sédimentologie, Stratigraphie, Géodynamique.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des

Cassiopeia A, Cygnus A, Taurus A, and Virgo A at ultra-low radio frequencies

This procedure is usually fast and it has been proven to be robust for observations with the High Band Antenna (HBA) system of the Low Frequency Array (LOFAR; van Haarlem et al.

Dissection of Axial-Pore Loop Function during Unfolding and Translocation by a AAA+ Proteolytic Machine

For the native V13P titin I27 domain, we find that parental ClpXP and the AYYYYY, AAYYYY, and AAAYYY variants almost never release the substrate, resulting in highly

Vue de Prévention et traitement de l’ostéoporose (première partie)

Après deux ans, dans le groupe recevant 5 mg d’alendronate, la DMO a augmenté signi- ficativement de 3,5 % à la colonne lombaire et de 1,9 % à la hanche par rapport aux valeurs