Download or read book Caracterisation experimentale du canal sous marin petit fond pour la transmission acoustique horizontale written by Dominique Jourdain and published by . This book was released on 1996 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: EN MILIEU SOUS-MARIN, LES PERFORMANCES DES SYSTEMES DE COMMUNICATION PAR VOIE ACOUSTIQUE SONT LIMITEES PAR LES CONDITIONS DE PROPAGATION: LE MILIEU EST BRUYANT, VARIABLE, DIFFUSEUR, MULTITRAJETS CELLES-CI SONT ENCORE PLUS DEFAVORABLES EN PETITS FONDS, EN RAISON DES INTERACTIONS MULTIPLES DES RAYONS SONORES AVEC LA SURFACE ET LE FOND. L'ETALEMENT DE LA REPONSE PEUT ALORS CORRESPONDRE A PLUSIEURS TEMPS SYMBOLES ET CREER DE L'INTERFERENCE ENTRE SYMBOLES TRANSMIS. PAR AILLEURS, L'ADDITION DES TRAJETS MULTIPLES PROVOQUENT DES EVANOUISSEMENTS EN RECEPTION. ENFIN, LE MILIEU EST TRES VARIABLE EN TEMPS, ET LES DIVERS MOUVEMENTS DE LA SURFACE ET DES TRANSDUCTEURS INDUISENT DE L'EFFET DOPPLER. CE TRAVAIL DE THESE PROPOSE UNE ETUDE AUSSI SYSTEMATIQUE QUE POSSIBLE DES CARACTERISTIQUES DU CANAL DE TRANSMISSION PETIT FOND DANS LA GAMME DES FREQUENCES UTILES AUX TRANSMISSIONS ACOUSTIQUES. IL EST BASE SUR DES SIGNAUX EXPERIMENTAUX ENREGISTRES SUR UNE QUINZAINE DE SITES DIFFERENTS. L'ENSEMBLE DES DONNEES RECUEILLIES COUVRE UNE LARGE VARIETE DE CONFIGURATIONS (HAUTEUR D'EAU, DISTANCE DE TRANSMISSION, ETATS DE SURFACE ET TYPE DE FOND). LES REPONSES IMPULSIONNELLES DU CANAL SONT OBTENUES PAR FILTRAGE ADAPTE DE SIGNAUX MODULES EN PHASE. LEUR ANALYSE PERMET D'ETUDIER L'INFLUENCE DES CONDITIONS EXPERIMENTALES SUR LA STRUCTURE DES TRAJETS MULTIPLES. LES RETARDS, AMPLITUDES ET PHASES DES TRAJETS PRINCIPAUX SONT ANALYSES DANS LA MESURE DU POSSIBLE ET DONNENT DES RENSEIGNEMENTS DIRECTS SUR LES QUALITES DES REFLEXIONS SURFACE ET FOND. ON EVALUE EGALEMENT L'INFLUENCE DES CONDITIONS DE PROPAGATION SUR LES PARAMETRES PERTINENTS POUR LA DEFINITION DES SYSTEMES DE TRANSMISSION DE DONNEES: ETALEMENT TEMPOREL, DOPPLER, TAUX DE FADING, FREQUENCES ET DUREES DES EVANOUISSEMENTS EN RECEPTION. UN CHAPITRE DE SYNTHESE EXAMINE LA VALEUR DES PARAMETRES OBTENUS EN FONCTION DES IMPERATIFS DE LA COMMUNICATION

Download or read book Caract risation exp rimentale du canal sous marin petit fond pour la transmission acoustique written by IFREMER (BREST). DIRECTION INGENIERIE TECHNOLOGIE INFORMATIQUE. ACOUSTIQUE SOUS MARINE. and published by . This book was released on 1996 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 2000 IEEE International Conference on Acoustics Speech and Signal Processing written by and published by . This book was released on 2000 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conception et evaluation d un systeme de transmission sur canal acoustique sous marin horizontal petits fonds written by Stéphane Coatélan and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conception et valuation d un syst me de transmission sur canal acoustique sous marin horizontal petits fonds written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal de Physique written by and published by . This book was released on 1991 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Caract risation d un canal non stationnaire et s lectif written by Hubert Mariotte and published by . This book was released on 1995 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: CETTE THESE TRAITE DE LA CARACTERISATION D'UN CANAL NON STATIONNAIRE ET SELECTIF. LA PROPAGATION DANS UN TEL CANAL EST CARACTERISEE PAR LA PRESENCE CONJOINTE DE TRAJETS MULTIPLES ET D'EFFET DOPPLER. CE TYPE DE CANAL SE RENCONTRE NOTAMMENT DANS LE CAS DES COMMUNICATIONS RADIOMOBILES OU DES COMMUNICATIONS ACOUSTIQUES SOUS-MARINES. NOUS NOUS SOMMES INTERESSES AU DEUXIEME TYPE DE CANAL. LE SIGNAL EMIS EST UN SIGNAL A MODULATION DE PHASE A DEUX ETATS, LE SIGNAL MODULANT ETANT UNE SEQUENCE BINAIRE A LONGUEUR MAXIMALE. COMPTE-TENU DES CONTRAINTES APPORTEES PAR LE CANAL DE PROPAGATION, LE SIGNAL RECU PEUT ETRE CONSIDERE COMME UNE SUITE D'ECHOS DU SIGNAL EMIS. CES ECHOS SONT RETARDES, ATTENUES ET DECALES EN FREQUENCE. NOUS AVONS MIS AU POINT, EN NOUS BASANT SUR LES IDEES DE L'ALGORITHME EM (EXPECTATION MAXIMIZATION), UN ALGORITHME ORIGINAL QUI PERMET D'ESTIMER LES DIFFERENTS PARAMETRES INTERVENANT DANS UNE PROPAGATION DE TYPE NON STATIONNAIRE ET SELECTIF. CES PARAMETRES SONT: L'ATTENUATION, L'INSTANT D'ARRIVEE ET LE DECALAGE DOPPLER DE CHAQUE ECHO DETECTE EN RECEPTION. NOUS AVONS APPELE CET ALGORITHME: ALGORITHME DE SYNTONISATION DES PICS INTERFERANTS. DES SIMULATIONS INFORMATIQUES ONT ETE EFFECTUEES AFIN DE VALIDER NOTRE APPROCHE ET D'ETUDIER LE COMPORTEMENT ET LA ROBUSTESSE DE L'ALGORITHME. ENFIN, L'ACQUISITION ET LE TRAITEMENT DE SIGNAUX ACOUSTIQUES REELS NOUS ONT PERMIS DE CARACTERISER LE CANAL ACOUSTIQUE SOUS-MARIN HORIZONTAL PAR PETITS FONDS. CETTE CARACTERISATION A ETE FAITE DANS DIFFERENTES CONFIGURATIONS: PROFONDEUR D'IMMERSION, DISTANCE EMETTEUR-RECEPTEUR, TYPE DE FOND

Download or read book The Journal of the Acoustical Society of America written by and published by . This book was released on 1977 with total page 1334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 The Behaviour of Teleost Fishes written by Tony J. Pitcher and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 559 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is about the behaviour of teleosts, a well-defined, highly successful, taxonomic group of vertebrate animals sharing a common body plan and forming the vast majority of living bony fishes. There are weH over 22000 living species of teleosts, including nearly all those of importance in com mercial fisheries and aquaculture. Teleosts are represented injust about every conceivable aquatic environment from temporary desert pools to the deep ocean, from soda lakes to sub-zero Antarctic waters. Behaviour is the primary interface between these effective survival machines and their environment: behavioural plasticity is one of the keys to their success. The study of animal behaviour has undergone revolutionary changes in the past decade under the dual impact of behavioural ecology and sociobiology. The modern body of theory provides quantitatively testable and experi mentaHy accessible hypotheses. Much current work in animal behaviour has concentrated on birds and mammals, animals with ostensibly more complex structure, physiology and behavioural capacity, but there is a growing body of information about the behaviour of fishes. There is now increasing awareness that the same ecological and evolutionary rules govern teleost fish, and that their behaviour is not just a simplified version of that seen in birds and mammals. The details of fish behaviour intimately reflect unique and efficient adaptations to their three-dimensional aquatic environment.

Download or read book Broken Music written by Ursula Block and published by . This book was released on 19?? with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Last Billion Years written by Atlantic Geoscience Society and published by Nimbus Publishing (CN). This book was released on 2001 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is about the history of the rocks and fossils of the Maritime Provinces of Canada (New Brunswick, Nova Scotia and PEI) over the last billion years. The book is beautifully illustrated in full colour, with original paintings of ancient vistas, over 150 photographs, and crisp explanatory diagrams and sketches.

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.

Download or read book The Mediterranean region under climate change written by Collectif and published by IRD Éditions. This book was released on 2018-11-19 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has been published by Allenvi (French National Alliance for Environmental Research) to coincide with the 22nd Conference of Parties to the United Nations Framework Convention on Climate Change (COP22) in Marrakesh. It is the outcome of work by academic researchers on both sides of the Mediterranean and provides a remarkable scientific review of the mechanisms of climate change and its impacts on the environment, the economy, health and Mediterranean societies. It will also be valuable in developing responses that draw on “scientific evidence” to address the issues of adaptation, resource conservation, solutions and risk prevention. Reflecting the full complexity of the Mediterranean environment, the book is a major scientific contribution to the climate issue, where various scientific considerations converge to break down the boundaries between disciplines.

Download or read book Routledge International Handbook of Ignorance Studies written by Matthias Gross and published by Routledge. This book was released on 2015-05-15 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: Once treated as the absence of knowledge, ignorance today has become a highly influential topic in its own right, commanding growing attention across the natural and social sciences where a wide range of scholars have begun to explore the social life and political issues involved in the distribution and strategic use of not knowing. The field is growing fast and this handbook reflects this interdisciplinary field of study by drawing contributions from economics, sociology, history, philosophy, cultural studies, anthropology, feminist studies, and related fields in order to serve as a seminal guide to the political, legal and social uses of ignorance in social and political life. Chapter 33 of this book is freely available as a downloadable Open Access PDF under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license available here: https://tandfbis.s3-us-west-2.amazonaws.com/rt-files/docs/Open+Access+Chapters/9780415718967_oachapter33.pdf

Download or read book Are We Here Yet written by Meg Stuart and published by Presses du Réel (Les). This book was released on 2010 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: "How does choreographer Meg Stuart create work? In this book, Stuart reflects on her own practice in dialogue with Jeroen Peeters and several (former) Damaged Goods collaborators"--P. 4 of cover.

Download or read book The African Shore written by Rodrigo Rey Rosa and published by Yale University Press. This book was released on 2013-10-22 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally published as La Orilla Africana. F&G Editores.