Centre dedocumentation
scientifique

The construction of sound speed field based on back propagation neural network in the global ocean / Junting Wang in Marine geodesy, vol 43 n° 6 (November 2020)  

Public [article]  inMarine geodesy > vol 43 n° 6 (November 2020) . - pp 621 - 642 Titre : The construction of sound speed field based on back propagation neural network in the global ocean Type de document : Article/Communication Auteurs : Junting Wang, Auteur ; Tianhe Xu, Auteur ; Wenfeng Nie, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 621 - 642 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes descripteurs IGN] fonction orthogonale [Termes descripteurs IGN] interpolation spatiale [Termes descripteurs IGN] milieu marin [Termes descripteurs IGN] onde acoustique [Termes descripteurs IGN] propagation du son [Termes descripteurs IGN] réseau neuronal artificiel [Termes descripteurs IGN] salinité [Termes descripteurs IGN] sondage acoustique [Termes descripteurs IGN] température [Termes descripteurs IGN] vitesse Résumé : (auteur) The sound speed is a key parameter that affects the underwater acoustic positioning and navigation. Aiming at the high-precision construction of sound speed field in the complex marine environment, this paper proposes a sound speed field model based on back propagation neural network (BPNN) by considering the correlation of learning samples. The method firstly uses measured ocean parameters to construct the temperature and salinity field. Then the spatial position, the temperature and the salinity information are used to construct the global ocean sound speed field based on the back propagation neural network algorithm. During the processing, the learning samples of back propagation neural network are selected based on the correlation between sound speed and distance. The proposed algorithm is validated by the global Argo data as well as compared with the spatial interpolation and the empirical orthogonal function (EOF) algorithm. The results demonstrate that the average root mean squares of the BPNN considering the correlation of learning samples is 0.352 m/s compared to the 1.527 m/s of EOF construction and the 2.661 m/s of spatial interpolation, with an improvement of 76.9% and 86.8%. Therefore, the proposed algorithm can improve the construction accuracy of sound speed field in the complex marine environment. Numéro de notice : A2020-694 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01490419.2020.1815912 date de publication en ligne : 14/09/2020 En ligne : https://doi.org/10.1080/01490419.2020.1815912 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96242 [article]

3D reconstruction of internal wood decay using photogrammetry and sonic tomography / Junjie Zhang in Photogrammetric record, vol 35 n° 171 (September 2020)  

Public [article]  inPhotogrammetric record > vol 35 n° 171 (September 2020) . - pp 357-374 Titre : 3D reconstruction of internal wood decay using photogrammetry and sonic tomography Type de document : Article/Communication Auteurs : Junjie Zhang, Auteur ; Kourosh Khoshelham, Auteur Année de publication : 2020 Article en page(s) : pp 357-374 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes descripteurs IGN] dépérissement [Termes descripteurs IGN] hauteur des arbres [Termes descripteurs IGN] interpolation spatiale [Termes descripteurs IGN] onde acoustique [Termes descripteurs IGN] qualité du bois [Termes descripteurs IGN] reconstruction 3D [Termes descripteurs IGN] temps de vol [Termes descripteurs IGN] tomographie [Termes descripteurs IGN] tronc [Termes descripteurs IGN] visualisation 3D Résumé : (Auteur) Knowledge of deteriorations within tree trunks is critical for arborists to conduct individual tree health assessments. Sonic tree tomography, a non‐destructive technique using sound waves, has been widely used to estimate the size and shape of internal decay based on sound wave velocity variations. However, it has commonly been applied to 2D horizontal or vertical cross sections and its accuracy is questionable due to the poor approximation of the shape of the cross section. This paper proposes an integration of close‐range photogrammetry and sonic tomography to enable accurate reconstruction of the exterior and interior of the tree trunk in 3D. The internal wood quality is represented by the spatially interpolated sound wave velocities, using the time of flight of the sound waves and the coordinates of the acoustic sensors obtained from the photogrammetric model. Experimental results show that the proposed approach provides a realistic 3D visualisation of the size, shape and location of the internal deteriorations. Numéro de notice : A2020-436 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/phor.12328 date de publication en ligne : 06/08/2020 En ligne : https://doi.org/10.1111/phor.12328 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95842 [article]

Use of non-destructive test methods on Irish hardwood standing trees and small-diameter round timber for prediction of mechanical properties / Daniel F. Llana in Annals of Forest Science [en ligne], vol 77 n° 3 (September 2020)  

Public [article]  inAnnals of Forest Science [en ligne] > vol 77 n° 3 (September 2020) Titre : Use of non-destructive test methods on Irish hardwood standing trees and small-diameter round timber for prediction of mechanical properties Type de document : Article/Communication Auteurs : Daniel F. Llana, Auteur ; Ian Short, Auteur ; Annette M. Harte, Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] acer pseudoplatanus [Termes descripteurs IGN] acoustique [Termes descripteurs IGN] Betula pendula [Termes descripteurs IGN] betula pubescens [Termes descripteurs IGN] bois sur pied [Termes descripteurs IGN] densité du bois [Termes descripteurs IGN] diamètre des arbres [Termes descripteurs IGN] éclaircie (sylviculture) [Termes descripteurs IGN] élagage (sylviculture) [Termes descripteurs IGN] élasticité [Termes descripteurs IGN] feuillu [Termes descripteurs IGN] fraxinus (genre) [Termes descripteurs IGN] fraxinus excelsior [Termes descripteurs IGN] Irlande [Termes descripteurs IGN] modèle de simulation [Termes descripteurs IGN] résonance [Termes descripteurs IGN] vent [Vedettes matières IGN] Sylviculture Résumé : (auteur) Key message: Mechanical properties of small-diameter round timber from hardwood thinnings of common alder ( Alnus glutinosa (L.) Gaertn.), European ash ( Fraxinus excelsior L.), European birch ( Betula pendula Roth. and Betula pubescens Ehrh.), and sycamore ( Acer pseudoplatanus L.) can be evaluated by non-destructive testing on either standing trees or green logs without wood density determination. Velocity differences between acoustic and resonance methods are influenced by tree species and age. Tree diameter improves the estimation of bending strength but not of stiffness. Context: There is a need for a reliable, fast, and inexpensive evaluation method to better sort hardwood thinnings according to mechanical properties for use in potential added-value applications. Aims: The estimation by non-destructive testing of mechanical properties of round small-diameter timber of four hardwood species (common alder, European ash, European birch, and sycamore). Methods: Acoustic velocity was measured in 38 standing trees and resonance velocity was recorded in green logs from these trees. The logs were then dried and tested in bending. Estimation models to predict mechanical properties from non-destructive testing measurements were developed. Results: Large differences between velocities from acoustic and resonance techniques were found. Models based on both non-destructive testing velocities together with a species factor are well correlated with bending modulus of elasticity while models including tree diameter are moderately well correlated with bending strength. Inclusion of density in the models does not improve the estimation. Conclusion: Models based on acoustic measurements on standing trees or resonance on green logs together with tree species and diameter provide reliable estimates of mechanical properties of round timber from hardwood thinnings. This methodology can be easily used for pre-sorting material in the forest. Numéro de notice : A2020-403 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-020-00957-x date de publication en ligne : 17/06/2020 En ligne : https://doi.org/10.1007/s13595-020-00957-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95453 [article]

Sensitivity of acoustic emission triggering to small pore pressure cycling perturbations during brittle creep / Kristel Chanard in Geophysical research letters, vol 46 n° 13 (16 July 2019)  

Public [article]  inGeophysical research letters > vol 46 n° 13 (16 July 2019) . - pp 7414 - 7423 Titre : Sensitivity of acoustic emission triggering to small pore pressure cycling perturbations during brittle creep Type de document : Article/Communication Auteurs : Kristel Chanard , Auteur ; Aurélien Nicolas, Auteur ; T. Hatano, Auteur ; F. Petrelis, Auteur ; Soumaya Latour, Auteur ; Sergio Vinciguerra, Auteur ; Alexandre Schubnel, Auteur Année de publication : 2019 Projets : 3-projet - voir note / Article en page(s) : pp 7414 - 7423 Note générale : bibliographie This work was funded by the Laboratoire de Recherche Commun “Yves Rocard” (ENS-CEA-CNRS) and the ERC Realism (2016-grant 681346). Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes descripteurs IGN] analyse de sensibilité [Termes descripteurs IGN] Fontainebleau, forêt de [Termes descripteurs IGN] grès [Termes descripteurs IGN] onde acoustique [Termes descripteurs IGN] séisme Résumé : (auteur) Fluid‐induced stress perturbations in the crust at seismogenic depths caused by sources such as tidal or seasonal loading may trigger earthquakes. We investigate the role of small periodic pore pressure (Pp) perturbation in rupture nucleation by performing laboratory triaxial creep experiments on Fontainebleau sandstone, saturated in water, under sinusoidal Pp variations. Results show that recorded acoustic emissions (AEs) correlate with Pp as the rock approaches failure. More interestingly, AEs occur significantly more when Pp is decreasing, that is, when strain rate is maximum with a progressive increase of Pp‐AEs correlation in time as the rock approaches failure. This suggests that the correlation of small stress perturbations and AEs not only depends on Pp amplitude but also on the criticality of the rock. Observations at the laboratory scale support field observations where tidal loading may have modulated seismic rates during the nucleation phase of the 2004 Sumatra‐Andaman and 2011 Tohoku‐Oki earthquakes. Numéro de notice : A2019-406 Affiliation des auteurs : Géodésie+Ext (mi2018-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/2019GL082093 date de publication en ligne : 01/07/2019 En ligne : https://doi.org/10.1029/2019GL082093 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93516 [article]

Physics of oscillations and waves / Arnt Inge Vistnes (2018)  

Public Titre : Physics of oscillations and waves Type de document : Monographie Auteurs : Arnt Inge Vistnes, Auteur Editeur : Springer Nature Année de publication : 2018 Importance : 594 p. Format : 16 x 24 cm ISBN/ISSN/EAN : 978-3-319-72314-3 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Physique [Termes descripteurs IGN] diffraction [Termes descripteurs IGN] interférence [Termes descripteurs IGN] longueur d'onde [Termes descripteurs IGN] onde [Termes descripteurs IGN] onde acoustique [Termes descripteurs IGN] onde électromagnétique [Termes descripteurs IGN] onde lumineuse [Termes descripteurs IGN] oscillation [Termes descripteurs IGN] phase [Termes descripteurs IGN] transformation de Fourier [Termes descripteurs IGN] transformation en ondelettes Résumé : (éditeur) In this textbook a combination of standard mathematics and modern numerical methods is used to describe a wide range of natural wave phenomena, such as sound, light and water waves, particularly in specific popular contexts, e.g. colors or the acoustics of musical instruments. It introduces the reader to the basic physical principles that allow the description of the oscillatory motion of matter and classical fields, as well as resulting concepts including interference, diffraction, and coherence. Numerical methods offer new scientific insights and make it possible to handle interesting cases that can’t readily be addressed using analytical mathematics; this holds true not only for problem solving but also for the description of phenomena. Essential physical parameters are brought more into focus, rather than concentrating on the details of which mathematical trick should be used to obtain a certain solution. Readers will learn how time-resolved frequency analysis offers a deeper understanding of the interplay between frequency and time, which is relevant to many phenomena involving oscillations and waves. Attention is also drawn to common misconceptions resulting from uncritical use of the Fourier transform. The book offers an ideal guide for upper-level undergraduate physics students and will also benefit physics instructors. Program codes in Matlab and Python, together with interesting files for use in the problems, are provided as free supplementary material. Note de contenu : 1- Introduction 2- Free and Damped Oscillations 3- Forced Oscillations and Resonance 4- Forced Oscillations and Resonance 5- Fourier Analysis 6- Waves 7- Sound 8- Dispersion and Waves on Water 9- Electromagnetic Waves 10- Reflection, Transmission and Polarization 11- Measurements of Light, Dispersion, Colours 12- Geometric Optics 13- Interference—Diffraction 14- Wavelet Transform 15- Coherence, Dipole Radiation and Laser 16- Skin Depth and Waveguides Numéro de notice : 25817 Affiliation des auteurs : non IGN Nature : Monographie En ligne : https://doi.org/10.1007/978-3-319-72314-3 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95082

Developing a wind turbine planning platform: Integration of “sound propagation model–GIS-game engine” triplet / Azarakhsh Rafiee in Environmental Modelling & Software, vol 95 (September 2017)  

Permalink

Urban soundscape maps modelled with geo-referenced data / Catherine Lavandier in Noise mapping, vol 3 n° 1 (October 2016)    

Permalink

Perception de l’ambiance sonore d’un lieu selon sa représentation visuelle : une analyse de corpus / Laura Ascone in Corela, vol 14 n° 1 (Février 2016)  

Permalink

Utilisation d’une source laser pulsée à haute energie comme source acoustique large bande en milieu liquide / Jean-Pierre Sessarego in Traitement du signal, vol 33 n° 1 (2016-1)

Permalink

Amélioration de la cartographie des ambiances sonores urbaines / Kamal Serrhini (2016) 

Permalink

Apport de la géodésie française fond de mer à l'évaluation de l'aléa sismique côtier : distancemétrie en mer de Marmara et simulation de GNSS/A aux Antilles / Pierre Sakic-Kieffer (2016)  

Permalink

Introduction to partial differential equations / David Borthwick (2016)  

Permalink

A novel method to correct for wood MOE ultrasonics and NIRS measurements on increment cores in Liquidambar styraciflua L / Herizo Rakotovololonalimanana in Annals of Forest Science [en ligne], vol 72 n° 6 (September 2015)  

Permalink

Visual encoding of acoustic parameters: framework and application to noise mapping / Jochen Schiewe in Cartographic journal (the), vol 50 n° 4 (November 2013)

Permalink

The art of the noise / N. Thurston in GEO: Geoconnexion international, vol 12 n° 3 (march 2013)

Permalink