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Species-specific deadwood density, its controlling factors and its role in the estimation of deadwood C stock of a Virgin European Beech-Silver Fir Mixed Forest in the Southern Carpathians / Ion Catalin Petritan in SSRN [preprint electronic journal], vol 2023 ([01/02/2023])  

Public [article]  inSSRN [preprint electronic journal] > vol 2023 [01/02/2023] Titre : Species-specific deadwood density, its controlling factors and its role in the estimation of deadwood C stock of a Virgin European Beech-Silver Fir Mixed Forest in the Southern Carpathians Type de document : Article/Communication Auteurs : Ion Catalin Petritan, Auteur Année de publication : 2023 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba [Termes IGN] bois mort [Termes IGN] Carpates [Termes IGN] décomposition [Termes IGN] densité du bois [Termes IGN] estimation statistique [Termes IGN] Fagus sylvatica [Termes IGN] peuplement mélangé [Termes IGN] puits de carbone [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) Deadwood is a fundamental structural and functional component of forests, with a crucial role in supporting the forest biodiversity and nutrient and carbon cycling. Precise deadwood density estimates are necessary to evaluate the biomass and carbon stocked in this component. For a better understanding of the deadwood dynamics in natural forests, given its higher abundance, it is important to achieve deeper knowledge about its decay rate and how it is influenced by environmental factors. In this study, we estimated dry deadwood density for two different tree species, silver fir (Abies alba) and European beech (Fagus sylvatica) and for three snags and five logs decomposition classes (class 1 representing snag/log deadwood at early stages of decomposition and class 3/5 representing snags or logs, respectively, at its most advanced state of decomposition) in a virgin mixed beech-fir forest in the Southern Carpathians. The goal of this study was to assess how deadwood density is influenced by different abiotic (moisture, elevation, slope, aspect) and wood-related factors (rottenness, position of the sampling along the deadwood piece, the contact with the soil).For snags, the mean dry density showed a reduced variability within decomposition classes (484-326 kg.m-3 for beech and 374-319 kg.m-3 for fir), compared to the logs (486-139 kg.m-3 for beech and 359-161 kg.m-3 for fir). While the mass moisture varied slowly in the first three decay classes (around 60-80%), it increased sharply in the last two decay classes of logs (> 140% in the fourth classes and > 350% in the last one). The rottenness increased with the decay degree in a similar way for both species. The contact of logs with the soil influenced positively the moisture of the log, but the position of the sampling along the piece did not play any significant role in the variability of density. The density estimates per decay classes were used to compare the amount of carbon (C) sequestered as deadwood for each species. The mean biomass of C as deadwood at Sinca virgin forest varied greatly among the 21 plots from 0.36 to 41.16 MgC ha-1, with a mean value of 15.96 ± 2.36 (±SE) MgC ha-1.Our study suggests that volume-based calculations might yield biased quantitative estimates of C stored as deadwood unless a local estimate of dead wood density corrected per species and decomposition class is applied. Moreover, using an averaged value of dry density instead of dry density value for each decay class may result in an overestimation of 22% on the estimation of C stock sequestered as deadwood. Thus, our study may also help planning future inventories of C stocks in other virgin forests and for other species, (e.g., make emphasis in estimating densities in all decay classes). Furthermore, it could serve as a methodological basis for more specific research designed to uncover the potential influence of different forest management practices on dry deadwood density. Numéro de notice : A2023-085 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.2139/ssrn.4350235 En ligne : https://dx.doi.org/10.2139/ssrn.4350235 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102857 [article]

Linear building pattern recognition in topographical maps combining convex polygon decomposition / Zhiwei Wei in Geocarto international, vol 38 n° inconnu ([01/01/2023])  

Public [article]  inGeocarto international > vol 38 n° inconnu [01/01/2023] Titre : Linear building pattern recognition in topographical maps combining convex polygon decomposition Type de document : Article/Communication Auteurs : Zhiwei Wei, Auteur ; Su Ding, Auteur ; Lu Cheng, Auteur ; et al., Auteur Année de publication : 2023 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] carte topographique [Termes IGN] construction [Termes IGN] décomposition [Termes IGN] détection du bâti [Termes IGN] forme linéaire [Termes IGN] généralisation cartographique automatisée [Termes IGN] Ordnance Survey (UK) [Termes IGN] polygone [Termes IGN] reconnaissance de formes Résumé : (auteur) Building patterns are crucial for urban form understanding, automated map generalization, and 3 D city model visualization. The existing studies have recognized various building patterns based on visual perception rules in which buildings are considered as a whole. However, some visually aware patterns may fail to be recognized with these approaches because human vision is also proved as a part-based system. This paper first proposed an approach for linear building pattern recognition combining convex polygon decomposition. Linear building patterns including collinear patterns and curvilinear patterns are defined according to the proximity, similarity, and continuity between buildings. Linear building patterns are then recognized by combining convex polygon decomposition, in which a building can be decomposed into sub-buildings for pattern recognition. A novel node concavity is developed based on polygon skeletons which is applicable for building polygons with holes or not in the building decomposition. And building’s orthogonal features are also considered in the building decomposition. Two datasets collected from Ordnance Survey (OS) were used in the experiments to verify the effectiveness of the proposed approach. The results indicate that our approach achieves 25.57% higher precision and 32.23% higher recall in collinear pattern recognition and 15.67% higher precision and 18.52% higher recall in curvilinear pattern recognition when compared to existing approaches. Recognition of other kinds of building patterns including T-shaped and C-shaped patterns combining convex polygon decomposition are also discussed in this approach. Numéro de notice : A2022-263 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/10106049.2022.2055794 Date de publication en ligne : 27/03/2022 En ligne : https://doi.org/10.1080/10106049.2022.2055794 Format de la ressource électronique : 27/03/2022 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100260 [article]

Structured binary neural networks for image recognition / Bohan Zhuang in International journal of computer vision, vol 130 n° 9 (September 2022)  

Public [article]  inInternational journal of computer vision > vol 130 n° 9 (September 2022) . - pp 2081 - 2102 Titre : Structured binary neural networks for image recognition Type de document : Article/Communication Auteurs : Bohan Zhuang, Auteur ; Chunhua Shen, Auteur ; Mingkui Tan, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 2081 - 2102 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] apprentissage profond [Termes IGN] décomposition [Termes IGN] détection d'objet [Termes IGN] implémentation (informatique) [Termes IGN] logique binaire [Termes IGN] segmentation sémantique Résumé : (auteur) In this paper, we propose to train binarized convolutional neural networks (CNNs) that are of significant importance for deploying deep learning to mobile devices with limited power capacity and computing resources. Previous works on quantizing CNNs often seek to approximate the floating-point information of weights and/or activations using a set of discrete values. Such methods, termed value approximation here, typically are built on the same network architecture of the full-precision counterpart. Instead, we take a new “structured approximation” view for network quantization — it is possible and valuable to exploit flexible architecture transformation when learning low-bit networks, which can achieve even better performance than the original networks in some cases. In particular, we propose a “group decomposition” strategy, termed GroupNet, which divides a network into desired groups. Interestingly, with our GroupNet strategy, each full-precision group can be effectively reconstructed by aggregating a set of homogeneous binary branches. We also propose to learn effective connections among groups to improve the representation capability. To improve the model capacity, we propose to dynamically execute sparse binary branches conditioned on input features while preserving the computational cost. More importantly, the proposed GroupNet shows strong flexibility for a few vision tasks. For instance, we extend the GroupNet for accurate semantic segmentation by embedding the rich context into the binary structure. The proposed GroupNet also shows strong performance on object detection. Experiments on image classification, semantic segmentation, and object detection tasks demonstrate the superior performance of the proposed methods over various quantized networks in the literature. Moreover, the speedup and runtime memory cost evaluation comparing with related quantization strategies is analyzed on GPU platforms, which serves as a strong benchmark for further research. Numéro de notice : A2022-637 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s11263-022-01638-0 Date de publication en ligne : 22/06/2022 En ligne : https://doi.org/10.1007/s11263-022-01638-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101443 [article]

Emissions of CO2 from downed logs of different species and the surrounding soil in temperate forest / Ewa Błońska in Annals of forest research, Vol 65 n° 2 (July - December 2022)  

Public [article]  inAnnals of forest research > Vol 65 n° 2 (July - December 2022) . - pp 47 - 56 Titre : Emissions of CO2 from downed logs of different species and the surrounding soil in temperate forest Type de document : Article/Communication Auteurs : Ewa Błońska, Auteur ; Wojciech Piaszczyk, Auteur ; Jaroslaw Lasota, Auteur Année de publication : 2022 Article en page(s) : pp 47 - 56 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba [Termes IGN] Alnus glutinosa [Termes IGN] bois mort [Termes IGN] Carpinus betulus [Termes IGN] décomposition [Termes IGN] dioxyde de carbone [Termes IGN] écosystème forestier [Termes IGN] forêt tempérée [Termes IGN] Pologne [Termes IGN] Populus tremula [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) The decomposition of deadwood plays a very important role in the functioning of the forest ecosystem. The present study was conducted with the objectives to: (1) determine the amount of deadwood respiration depending on species and degree of decomposition; (2) determine the extent of the impact of decomposing wood on the amount of respiration in surrounding soil; (3) find a relationship between the amount of respiration and the chemical fractional composition of soil organic matter. Our research has shown that respiration of decaying wood samples was 2-3 times lower compared to soil, regardless of the type of wood and the degree of wood decomposition. The conducted analyses confirmed the influence of the species of wood and the degree of decomposition on the respiration rate in wood samples. More decomposed wood (4th and 5th degree of decomposition) releases more CO2 compared to less decomposed wood and the highest CO2 emissions were recorded for aspen and alder wood. Better understanding of the mechanisms and factors affecting CO2 emissions in forest ecosystem can help reduce climate change. Numéro de notice : A2022-906 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.15287/afr.2022.2386 Date de publication en ligne : 28/12/2022 En ligne : https://doi.org/10.15287/afr.2022.2386 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102322 [article]

Self-shadowing of a spacecraft in the computation of surface forces : An example in planetary geodesy / Georges Balmino in Artificial satellites, vol 53 n° 1 (March 2018)  

Public [article]  inArtificial satellites > vol 53 n° 1 (March 2018) . - pp 1 - 27 Titre : Self-shadowing of a spacecraft in the computation of surface forces : An example in planetary geodesy Type de document : Article/Communication Auteurs : Georges Balmino, Auteur ; J.C. Marty, Auteur Année de publication : 2018 Article en page(s) : pp 1 - 27 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales [Termes IGN] décomposition [Termes IGN] détection d'ombre [Termes IGN] engin spatial [Termes IGN] Mars (planète) [Termes IGN] problème inverse [Termes IGN] surface (géométrie) Résumé : (auteur) We describe in details the algorithms used in modelling the self-shadowing between spacecraft components, which appears when computing the surface forces as precisely as possible and especially when moving parts are involved. This becomes necessary in planetary geodesy inverse problems using more and more precise orbital information to derive fundamental parameters of geophysical interest. Examples are given with two Mars orbiters, which show significant improvement on drag and solar radiation pressure model multiplying factors, a prerequisite for improving in turn the determination of other global models. Numéro de notice : A2018-173 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.2478/arsa-2018-0002 Date de publication en ligne : 24/03/2018 En ligne : https://doi.org/10.2478/arsa-2018-0002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89813 [article]

Per-pixel bias-variance decomposition of continuous errors in data-driven geospatial modeling : A case study in environmental remote sensing / Jing Gao in ISPRS Journal of photogrammetry and remote sensing, vol 134 (December 2017)  

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Point cloud refinement with self-calibration of a mobile multibeam lidar sensor / Houssem Nouira in Photogrammetric record, vol 32 n° 159 (September 2017)  

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Urban damage level mapping based on scattering mechanism investigation using fully polarimetric SAR Data for the 3.11 East Japan earthquake / Si-Wei Chen in IEEE Transactions on geoscience and remote sensing, vol 54 n° 12 (December 2016)  

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Outlier detection by using fault detection and isolation techniques in geodetic networks / U.M. Durdag in Survey review, vol 48 n° 351 (October 2016)  

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A tensor decomposition-based anomaly detection algorithm for hyperspectral image / Xing Zhang in IEEE Transactions on geoscience and remote sensing, vol 54 n° 10 (October 2016)  

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Empirical waveform decomposition and radiometric calibration of a terrestrial full-waveform laser scanner / Preston J. Hartzell in IEEE Transactions on geoscience and remote sensing, vol 53 n° 1 (January 2015)  

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L’approche cartographique de la décomposition des matrices de flux / Françoise Bahoken in Mappemonde, n° 116 (2014-4)  

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On the exponential decay to equilibrium of the degenerate linear Boltzmann equation / Etienne Bernard in Journal of functional analysis, vol 265 n° 9 (November 2013)  

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Establishing forest inventory reference definitions for forest and growing stock: a study towards common reporting / Claude Vidal in Silva fennica, vol 42 n° 2 (2008)  

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Multi-dimensional B-spline modeling of spatio-temporal Ionospheric signals / C. Zeilhofer (2008)

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