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Three-dimensional reconstruction of seismo-traveling ionospheric disturbances after March 11, 2011, Japan Tohoku earthquake / Changzhi Zhai in Journal of geodesy, vol 95 n° 7 (July 2021)  

Public [article]  inJournal of geodesy > vol 95 n° 7 (July 2021) . - n° 77 Titre : Three-dimensional reconstruction of seismo-traveling ionospheric disturbances after March 11, 2011, Japan Tohoku earthquake Type de document : Article/Communication Auteurs : Changzhi Zhai, Auteur ; Yibin Yao, Auteur ; Jian Kong, Auteur Année de publication : 2021 Article en page(s) : n° 77 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] diffusion de Rayleigh [Termes IGN] GeoNet [Termes IGN] modèle ionosphérique [Termes IGN] onde acoustique [Termes IGN] perturbation ionosphérique [Termes IGN] reconstruction 3D [Termes IGN] séisme [Termes IGN] signal GPS [Termes IGN] teneur totale en électrons [Termes IGN] Tohoku (Japon) [Termes IGN] tomographie Résumé : (auteur) The electron density structures of the seismo-traveling ionospheric disturbances (STIDs) during the Tohoku earthquake are reconstructed by applying the three-dimensional computerized ionospheric tomography (3DCIT) technique with a 30-s time resolution for the first time. The vertical distribution of 3DCIT results is consistent with the constellation observing system for meteorology, ionosphere and climate (COSMIC) observations. The horizontal speeds of STIDs at different altitudes are estimated, and the three types of STIDs related to Rayleigh waves, acoustic waves and gravity waves are identified by their propagation characters. The magnitude of STIDs related to Rayleigh waves decreased with altitude, and there was no significant difference between the speeds (~ 2500 m/s) at different altitudes. The STIDs caused by acoustic waves traveled faster at 300 km altitude (~ 666–724 m/s) than at 150 km altitude (~ 500–550 m/s). From 150 to 250 km altitudes, in the STIDs induced by gravity waves, the magnitude of positive and negative wave fronts showed the opposite trend. The speed at 300 km altitude (~ 332 m/s) was slightly larger than at 150 km altitude (~ 310 m/s). The Rayleigh waves related STIDs showed a conic-like geometry, whereas the acoustic waves and gravity waves induced STIDs showed inverted conic-like geometries. The possible propagation mechanisms of different types of STIDs are also discussed. Numéro de notice : A2021-524 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-021-01533-5 date de publication en ligne : 23/06/2021 En ligne : https://doi.org/10.1007/s00190-021-01533-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97961 [article]

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 IGN] fonction orthogonale [Termes IGN] interpolation spatiale [Termes IGN] milieu marin [Termes IGN] onde acoustique [Termes IGN] propagation du son [Termes IGN] réseau neuronal artificiel [Termes IGN] salinité [Termes IGN] sondage acoustique [Termes IGN] température [Termes 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 IGN] dépérissement [Termes IGN] hauteur des arbres [Termes IGN] interpolation spatiale [Termes IGN] onde acoustique [Termes IGN] qualité du bois [Termes IGN] reconstruction 3D [Termes IGN] temps de vol [Termes IGN] tomographie [Termes IGN] tronc [Termes 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 IGN] Acer pseudoplatanus [Termes IGN] acoustique [Termes IGN] Betula pendula [Termes IGN] betula pubescens [Termes IGN] bois sur pied [Termes IGN] densité du bois [Termes IGN] diamètre des arbres [Termes IGN] éclaircie (sylviculture) [Termes IGN] élagage (sylviculture) [Termes IGN] élasticité [Termes IGN] feuillu [Termes IGN] Fraxinus (genre) [Termes IGN] Fraxinus excelsior [Termes IGN] Irlande [Termes IGN] modèle de simulation [Termes IGN] résonance [Termes 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 IGN] analyse de sensibilité [Termes IGN] Fontainebleau, forêt de [Termes IGN] grès [Termes IGN] onde acoustique [Termes 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)  

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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)  

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

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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)  

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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)

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

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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)  

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Introduction to partial differential equations / David Borthwick (2016)  

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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)  

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

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