Download or read book Traitement des signaux par des m thodes de reconnaissance de formes application l mission acoustique written by Abderraouf Chaari and published by . This book was released on 1980 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rappel des caractéristiques essentielles de l'émission acoustique, description des procédures d'acquisition et des systèmes de traitement. Les techniques de reconnaissance des formes supposent que l'on a au préalable extrait les caractères essentiels du signal. On présente deux méthodes : l'une sur la représentation temporelle du signal, l'autre sur sa représentation fréquentielle. On donne également les méthodes permettant de réduire ce nombre de caractères en contrôlant la perte d'information et le principe de la technique de reconnaissance de formes utilisée. On présente l'ensemble des résultats obtenus sur des éprouvettes de polymères

Download or read book COMPARAISONS EXPERIMENTALES DE METHODES DE TRAITEMENT DE SIGNAUX COURTS written by ERIC.. BOURBAO and published by . This book was released on 1994 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: LA DUREE RELATIVEMENT REDUITE DE CERTAINS SIGNAUX PAR RAPPORT AU TEMPS DE COHERENCE DU BRUIT LEUR CONFERE LE QUALIFICATIF DE SIGNAUX COURTS. LE TRAITEMENT DE TELS SIGNAUX NECESSITE SOUVENT L'UTILISATION DE METHODES SPECIFIQUES. NOUS PRESENTONS, DANS UN CADRE EXPERIMENTAL, DIFFERENTES TECHNIQUES DEDIEES AU TRAITEMENT DE SIGNAUX COURTS DANS LE DOMAINE DE L'ACOUSTIQUE SOUS-MARINE. LES METHODES DE REPRESENTATIONS TEMPS-FREQUENCE CONVIENNENT BIEN A L'ANALYSE DES SIGNAUX COURTS. LA MULTIPLICITE DE CES TECHNIQUES, NOUS A CONDUIT A MENER UNE ETUDE COMPARATIVE DONT NOUS EXPOSONS LES RESULTATS QUALITATIFS D'ABORD A L'AIDE D'UN SIGNAL TEST SIMULE PUIS EN LES APPLIQUANT SUR UN SIGNAL D'ACOUSTIQUE SOUS-MARINE. NOUS ABORDONS EGALEMENT LE PROBLEME DE LA DETECTION DE SIGNAUX COURTS EN PRESENTANT UNE EXTENSION DE LA NOTION DE FILTRAGE ADAPTE AUX SIGNAUX POSSEDANT UN CERTAIN ALEA. NOS PROPOS SONT ILLUSTRES PAR L'APPLICATION DE CETTE TECHNIQUE SUR DES SIGNAUX EXPERIMENTAUX. ENFIN, NOUS NOUS SOMMES INTERESSES A L'EXTRACTION DE SIGNAUX NOYES DANS DU BRUIT SPATIALEMENT LOCALISE. NOUS AVONS AINSI DEVELOPPE UNE METHODE QUI PERMET, LORSQU'ON DISPOSE D'UNE ANTENNE LINEAIRE, D'ESTIMER LE FILTRE DE WIENER ASSOCIE AU SIGNAL UTILE A L'AIDE DES VOIES FORMEES DANS LES DIRECTIONS DES SOURCES ACOUSTIQUES PRESENTES. APRES UNE PRESENTATION GENERALE DE CETTE TECHNIQUE NOUS MONTRONS L'INTERET DE SON UTILISATION CONJOINTEMENT A UNE ANALYSE TEMPS-FREQUENCE AU MOYEN DE LA TRANSFORMEE DE FOURIER A COURT TERME

Download or read book Traitement d un signal acoustique written by Samy Branci and published by . This book was released on 1995 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: PARMI LES TECHNIQUES DE CONTROLE NON DESTRUCTIF DES OUTILS EN MECANIQUE, LA SURVEILLANCE PAR L'EMISSION ACOUSTIQUE SE REVELE EFFICACE POUR FOURNIR UNE INFORMATION SUR LE PROCESSUS DE COUPE, L'ETAT DE L'OUTIL ET LA QUALITE DE LA PIECE A TRAVAILLER. DANS CE CONTEXTE, NOUS AVONS ETUDIE LE SIGNAL, SON SPECTRE ET PROPOSE UNE INTERPRETATION DU MECANISME D'ABRASION A PARTIR DES RESULTATS OBTENUS. A L'AIDE D'UN RESEAU DE NEURONES, DES CARTES DE KOHONEN ONT ETE CONSTRUITES: LES DIFFERENTS PROCESSUS DE COUPE PEUVENT ETRE DIFFERENCIES SELON L'EMISSION ACOUSTIQUE. PARALLELEMENT, CES EMISSIONS ACOUSTIQUES BRUTES SONT TRAITEES PAR UNE METHODE DE TRAITEMENT DU SIGNAL UTILISANT LES ONDELETTES. CETTE TECHNIQUE DE FILTRAGE OFFRE PLUSIEURS AVANTAGES (MULTI-RESOLUTION TEMPORELLE ET EN FREQUENCE), EXPLOITES ICI POUR FILTRER ET REDUIRE LES DONNEES ISSUES DU CAPTEUR ACOUSTIQUE. UNE ANALYSE STATISTIQUE SUR LES TRANSFORMEES EN ONDELETTES, A DONNE DES RESULTATS EXPLOITABLES POUR UNE CONSTRUCTION D'UN SYSTEME DE SURVEILLANCE ACOUSTIQUE

Download or read book M thodologie de traitement et d analyse de signaux exp rimentaux d mission acoustique written by Oumar Issiaka Traore and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'objectif de cette thèse est de contribuer à l'amélioration du processus de dépouillement d'essais de sûreté visant étudier le comportement d'un combustible nucléaire en contexte d'accident d'injection de réactivité (RIA), via la technique de contrôle par émission acoustique. Il s'agit notamment d'identifier clairement les mécanismes physiques pouvant intervenir au cours des essais à travers leur signature acoustique. Dans un premier temps, au travers de calculs analytiques et des simulation numériques conduites au moyen d'une méthode d'éléments finis spectraux, l'impact du dispositif d'essais sur la propagation des ondes est étudié. Une fréquence de résonance du dispositif est identifiée. On établit également que les mécanismes basses fréquences ne sont pas impactés par le dispositif d'essais. En second lieu, diverses techniques de traitement du signal (soustraction spectrale, analyse spectrale singulière, ondelettes. . . ) sont expérimentées, afin de proposer des outils permettant de traiter différent types de bruit survenant lors des essais RIA. La soustraction spectrale s'avère être la méthode la plus robuste aux changements de nature du bruit, avec un fort potentiel d'amélioration du rapport signal-à-bruit. Enfin, des méthodes d'analyse de données multivariées et d'analyse de données fonctionnelles ont été appliquées, afin de proposer un algorithme de classification statistique permettant de mieux comprendre la phénoménologie des accidents de type RIA et d'identifier les mécanismes physiques. Selon l'approche (multivariée ou fonctionnelle), les algorithmes obtenus permettent de reconnaître le mécanisme associé à une salve dans plus de 80% des cas.

Download or read book Acoustics of Porous Media written by Thierry Bourbié and published by Editions TECHNIP. This book was released on 1987 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dictionary of Building and Civil Engineering written by Don Montague and published by Taylor & Francis. This book was released on 1996 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dual-language dictionary lists over 20,000 specialist terms in both French and English, covering architecture, building, engineering and property terms. It meets the needs of all building professionals working on projects overseas. It has been comprehensively researched and compiled to provide an invaluable reference source in an increasingly European marketplace.

Download or read book Estimation with Applications to Tracking and Navigation written by Yaakov Bar-Shalom and published by John Wiley & Sons. This book was released on 2004-04-05 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expert coverage of the design and implementation of state estimation algorithms for tracking and navigation Estimation with Applications to Tracking and Navigation treats the estimation of various quantities from inherently inaccurate remote observations. It explains state estimator design using a balanced combination of linear systems, probability, and statistics. The authors provide a review of the necessary background mathematical techniques and offer an overview of the basic concepts in estimation. They then provide detailed treatments of all the major issues in estimation with a focus on applying these techniques to real systems. Other features include: * Problems that apply theoretical material to real-world applications * In-depth coverage of the Interacting Multiple Model (IMM) estimator * Companion DynaEst(TM) software for MATLAB(TM) implementation of Kalman filters and IMM estimators * Design guidelines for tracking filters Suitable for graduate engineering students and engineers working in remote sensors and tracking, Estimation with Applications to Tracking and Navigation provides expert coverage of this important area.

Download or read book Submarine Mass Movements and Their Consequences written by Vasilios Lykousis and published by Springer Science & Business Media. This book was released on 2007-09-14 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions from leading researchers in science and engineering, this book provides a global perspective on submarine mass movements and their consequences. Authors report on new findings from fundamental as well as site-specific studies from around the world. All studies relied on the most recent technologies, including multi-beam sonar imaging techniques, 3D seismic analysis, slope stability analysis, debris flow, and tsunami modeling.

Download or read book Historical journey in a linguistic archipelago written by Émilie Aussant and published by BoD – Books on Demand. This book was released on 2020-12-14 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume offers a selection of papers presented during the 14th International Conference on the History of the Language Sciences (ICHoLS XIV, Paris, 2017). Part I brings together studies dealing with descriptive concepts. First examined is the notion of “accidens” in Latin grammar and its Greek counterparts. Other papers address questions with a strong echo in today’s linguistics: localism and its revival in recent semantics and syntax, the origin of the term “polysemy” and its adoption through Bréal, and the difficulties attending the description of prefabs, idioms and other “fixed expressions”. This first part also includes studies dealing with representations of linguistic phenomena, whether these concern the treatment of local varieties (so-called patois) in French research, or the import and epistemological function of spatial representations in descriptions of linguistic time. Or again, now taking the word “representation” literally, the visual display of grammatical relations, in the form of the first syntactic diagrams. Part II presents case studies which involve wider concerns, of a social nature: the “from below” approach to the history of Chinese Pidgin English underlines the social roles of speakers and the diversity of speech situations, while the scrutiny of Lhomond’s Latin and French textbooks demonstrates the interplay of pedagogical practice, cross-linguistic comparison and descriptive innovation. An overview of early descriptions of Central Australian languages reveals a whole spectrum of humanist to positivist and antihumanist stances during the colonial age. An overarching framework is also at play in the anthropological perspective championed by Meillet, whose socially and culturally oriented semantics is shown to live on in Benveniste. The volume ends with a paper on Trần Đức Thảo, whose work is an original synthesis between phenomenology and Marxist semiology, wielded against the “idealistic” doctrine of Saussure.

Download or read book The Online Informal Learning of English written by G. Sockett and published by Springer. This book was released on 2014-09-26 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: Young people around the world are increasingly able to access English language media online for leisure purposes and interact with other users of English. This book examines the extent of these phenomena, their effect on language acquisition and their implications for the teaching of English in the 21st century.

Download or read book Special Welding Techniques written by John Mueller and published by . This book was released on 1957 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Streaming Media Architectures Techniques and Applications Recent Advances written by Zhu, Ce and published by IGI Global. This book was released on 2010-09-30 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book spans a number of interdependent and emerging topics in streaming media, offering a comprehensive collection of topics including media coding, wireless/mobile video, P2P media streaming, and applications of streaming media"--Provided by publisher.

Download or read book The Disappearing Computer written by Norbert Streitz and published by Springer. This book was released on 2007-07-20 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines how the computer, as we currently know it, will be replaced by a new generation of technologies, moving computing off the desktop and ultimately integrating it with real world objects and everyday environments. It provides a unique combination of concepts, methods and prototypes of ubiquitous and pervasive computing reflecting the current interest in smart environments and ambient intelligence.

Download or read book European Seagrasses written by Jens Borum and published by . This book was released on 2004 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of the report project is to define the habitat requirements of seagrasses in the European coasts, the present threats to the sustainability of the ecosystem they form, and their resilience to disturbance in order to strengthen our forecast capacity and formulate cost-effective monitoring plans and management strategies.

Download or read book CIKM 13 written by CIKM 13 Conference Committee and published by . This book was released on 2013-10-27 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt: CIKM'13: 22nd ACM International Conference on Information and Knowledge Management Oct 27, 2013-Nov 01, 2013 San Francisco, USA. You can view more information about this proceeding and all of ACM�s other published conference proceedings from the ACM Digital Library: http://www.acm.org/dl.

Download or read book Advances in Rotorcraft Technology written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Flight Vehicle Integration Panel. Symposium and published by . This book was released on 1997 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In Vessel Melt Retention and Ex Vessel Corium Cooling IAEA Tecdoc No 1906 written by International Atomic Energy Agency and published by International Atomic Energy Agency. This book was released on 2020-08-06 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication results from a technical meeting on phenomenology and technologies relevant to in-vessel melt retention (IVMR) and ex-vessel corium cooling (EVCC). The purpose of the publication is to capture the state of knowledge, at the time of that meeting, related to phenomenology and technologies as well as the challenges and pending issues relevant to IVMR and EVCC for water cooled reactors by summarizing the information provided by the meeting participants in a form useful to practitioners in Member States.