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De l’origine des Pins de montagne européens / Renaud Cantegrel in Revue forestière française, vol 71 n° 3 (2019)
[article]
Titre : De l’origine des Pins de montagne européens Type de document : Article/Communication Auteurs : Renaud Cantegrel, Auteur Année de publication : 2019 Note générale : bibliographie Langues : Français (fre) Descripteur : [Termes IGN] biodiversité végétale
[Termes IGN] changement climatique
[Termes IGN] ère tertiaire
[Termes IGN] forêt alpestre
[Termes IGN] génétique forestière
[Termes IGN] Pinus mugo subsp. uncinata
[Termes IGN] Pinus mugo Turra
[Termes IGN] Pinus sylvestris
[Termes IGN] taxinomie
[Termes IGN] tourbière
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Sur la base d’une abondante revue bibliographique, l’auteur ébauche les séquences évolutives des Pins sauvages européens (Pinus sylvestris et Pins de montagne) au cours des dernières périodes du Cénozoïque. Il en déduit la vraisemblance d’une divergence récente entre Pinus uncinata et Pinus mughus, n’excédant pas 3 Ma bp, et ses investigations de terrain le conduisent à différencier les deux espèces autant par leur destinée écogéographique que par leur autécologie. Sous la pression des bouleversements climatiques subis, et particulièrement en réponse aux migrations forcées par les glaciations européennes depuis la fin de l’ère tertiaire, l’introgression entre leurs populations sympatriques génère une série de taxons intermédiaires dont l’ensemble constitue le complexe des Pins de montagne. Le rôle du Pin sylvestre est souligné par son apport génétique décisif dans l’organisation de la biodiversité au sein du complexe spécifique. Numéro de notice : A2020-219 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.4267/2042/70704 En ligne : https://doi.org/10.4267/2042/70704 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94913
in Revue forestière française > vol 71 n° 3 (2019)[article]
Titre : Ensemble methods for pedestrian detection in dense crowds Type de document : Thèse/HDR Auteurs : Jennifer Vandoni, Auteur ; Sylvie Le Hégarat-Mascle, Directeur de thèse Editeur : Paris-Orsay : Université de Paris 11 Paris-Sud Centre d'Orsay Année de publication : 2019 Importance : 182 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse de Doctorat de l'Université Paris-Saclay, Sciences et technologies de l’information et de la communication (STIC), Spécialité : Traitement du Signal et des ImagesLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] algorithme d'apprentissage
[Termes IGN] apprentissage dirigé
[Termes IGN] apprentissage profond
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] comportement
[Termes IGN] densité de population
[Termes IGN] détection de piéton
[Termes IGN] données multicapteurs
[Termes IGN] étalonnage
[Termes IGN] fusion de données
[Termes IGN] taxinomie
[Termes IGN] théorie de Dempster-ShaferIndex. décimale : THESE Thèses et HDR Résumé : (auteur) The interest surrounding the study of crowd phenomena spanned during the last decade across multiple fields, including computer vision, physics, sociology, simulation and visualization. There are different levels of granularity at which crowd studies can be performed, namely a finer microanalysis, aimed to detect and then track each pedestrian individually; and a coarser macro-analysis, aimed to model the crowd as a whole.
One of the most difficult challenges when working with human crowds is that usual pedestrian detection methodologies do not scale well to the case where only heads are visible, for a number of reasons such as absence of background, high visual homogeneity, small size of the objects, and heavy occlusions. For this reason, most micro-analysis studies by means of pedestrian detection and tracking methodologies are performed in low to medium-density crowds, whereas macro-analysis through density estimation and people counting is more suited in presence of high-density crowds, where the exact position of each individual is not necessary. Nevertheless, in order to analyze specific events involving high-density crowds for monitoring the flow and preventing disasters such as stampedes, a complete understanding of the scene must be reached. This study deals with pedestrian detection in high-density crowds from a monocamera system, striving to obtain localized detections of all the individuals which are part of an extremely dense crowd. The detections can be then used both to obtain robust density estimation, and to initialize a tracking algorithm. In presence of difficult problems such as our application, supervised learning techniques are well suited. However, two different questions arise, namely which classifier is the most adapted for the considered environment, and which data to use to learn from. We cast the detection problem as a Multiple Classifier System (MCS), composed by two different ensembles of classifiers, the first one based on SVM (SVM-ensemble) and the second one based on CNN (CNN-ensemble), combined relying on the Belief Function Theory (BFT) designing a fusion method which is able to exploit their strengths for pixel-wise classification. SVM-ensemble is composed by several SVM detectors based on different gradient, texture and orientation descriptors, able to tackle the problem from different perspectives. BFT allows us to take into account the imprecision in addition to the uncertainty value provided by each classifier, which we consider coming from possible errors in the calibration procedure and from pixel neighbor’s heterogeneity in the image space due to the close resolution of the target (head) and
descriptor respectively. However, scarcity of labeled data for specific dense crowd contexts reflects in the impossibility to easily obtain robust training and validation sets. By exploiting belief functions directly derived
from the classifiers’ combination, we therefore propose an evidential Query-by-Committee (QBC) active learning algorithm to automatically select the most informative training samples. On the other side, we explore deep learning techniques by casting the problem as a segmentation task in presence of soft labels, with a fully convolutional network architecture designed to recover small objects (heads) thanks to a tailored use of dilated convolutions. In order to obtain a pixel-wise measure of reliability about the network’s predictions, we create a CNN-ensemble by means of dropout at inference time, and we combine the different obtained realizations in the
context of BFT. To conclude, we show that the dense output map given by the MCS can be employed not only
for pedestrian detection at microscopic level, but also to perform macroscopic analysis, bridging the gap between the two levels of granularity. We therefore finally focus our attention to people counting, proposing an evaluation method that can be applied at every scale, resulting to be more precise in the error and uncertainty evaluation (disregarding possible compensations) as well as more useful for the modeling community that could use it to improve and validate local density estimation.Note de contenu : 1- Crowd understanding
2- Supervised learning and classifier combination
3- SVM descriptors for pedestrian detection in high-density crowds
4- Taking into account imprecision with Belief Function Framework
5- Evidential QBC Active Learning
6- CNNs for pedestrian detection in high-density crowds
7- CNN-ensemble and evidential Multiple Classifier System
8- Density Estimation
ConclusionNuméro de notice : 25704 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Traitement du Signal et des Images : Paris 11 : 2019 Organisme de stage : Systèmes et applications des technologies de l'information et de l'énergie (Paris) nature-HAL : Thèse DOI : sans En ligne : https://theses.hal.science/tel-02318892/document Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94838
Titre : Scalable evaluation of 3D city models Type de document : Article/Communication Auteurs : Oussama Ennafii , Auteur ; Arnaud Le Bris , Auteur ; Florent Lafarge, Auteur ; Clément Mallet , Auteur Editeur : Saint-Mandé : Institut national de l'information géographique et forestière - IGN (2012-) Année de publication : 2019 Projets : 1-Pas de projet / Conférence : IGARSS 2019, IEEE International Geoscience And Remote Sensing Symposium 28/07/2019 02/08/2019 Yokohama Japon Proceedings IEEE Importance : 4 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse de données
[Termes IGN] classification dirigée
[Termes IGN] fusion d'images
[Termes IGN] fusion de données
[Termes IGN] image à très haute résolution
[Termes IGN] modélisation 3D du bâti BIM
[Termes IGN] taxinomieRésumé : (Auteur) The generation of 3D building models from Very High Resolution geospatial data is now an automatized procedure. However, urban areas are very complex and practitioners still have to visually assess the correctness of these models and detect reconstruction errors. We proposed an approach for automatically evaluating the quality of 3D building models. It is cast as a supervised classification task based on a hierarchical taxonomy and multimodal handcrafted features (building geometry, optical images, height data). In this paper, we evaluate how the urban area composition impacts prediction transferability and scalability of our framework to unseen scenes. This allows to define minimal feature and training sets for a problem where no benchmark data has been released so far. Numéro de notice : C2019-006 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Autre URL associée : vers HAL Thématique : IMAGERIE/URBANISME Nature : Poster nature-HAL : Poster-avec-CL DOI : 10.1109/IGARSS.2019.8899337 Date de publication en ligne : 14/11/2019 En ligne : https://doi.org/10.1109/IGARSS.2019.8899337 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92592 Semantic aware quality evaluation of 3D building models : Modeling and simulation / Oussama Ennafii (2019)
Titre : Semantic aware quality evaluation of 3D building models : Modeling and simulation Titre original : Evaluation de la qualité des modèles 3D de bâtiments Type de document : Thèse/HDR Auteurs : Oussama Ennafii , Auteur ; Clément Mallet , Directeur de thèse ; Florent Lafarge, Directeur de thèse Editeur : Champs/Marne : Université Paris-Est Année de publication : 2019 Importance : 238 p. Format : 21 x 30 cm Note générale : bibliographie
Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy delivered by Université Paris-Est, Speciality Geographical Information Sciences and Technologies
Thèse récompensée par le prix 2020 EuroSDR PhD Award.Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] apprentissage automatique
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] détection d'erreur
[Termes IGN] généralisation
[Termes IGN] image à très haute résolution
[Termes IGN] information sémantique
[Termes IGN] modèle 3D de l'espace urbain
[Termes IGN] modèle numérique de surface
[Termes IGN] modélisation 3D
[Termes IGN] modélisation du bâti
[Termes IGN] scène urbaine
[Termes IGN] taxinomieIndex. décimale : THESE Thèses et HDR Résumé : (auteur) The automatic generation of 3D building models from geospatial data is now a standard procedure. An abundant literature covers the last two decades and several softwares are now available. However, urban areas are very complex environments. Inevitably, practitioners still have to visually assess, at city-scale, the correctness of these models and detect frequent reconstruction errors. Such a process relies on experts, and is highly time-consuming with approximately two hours/km² per expert. This work proposes an approach for automatically evaluating the quality of 3D building models. Potential errors are compiled in a novel hierarchical and modular taxonomy. This allows, for the first time, to disentangle fidelity and modeling errors, whatever the level of details of the modeled buildings. The quality of models is predicted using the geometric properties of buildings and, when available, Very High Resolution images and Digital Surface Models. A baseline of handcrafted, yet generic, features is fed into a Random Forest or Support Vector Machine classifiers. Richer features, relying on graph kernels as well as Scattering Networks, were proposed to better take into consideration structure. Both multi-class and multi-label cases are studied: due to the interdependence between classes of errors, it is possible to retrieve all errors at the same time while simply predicting correct and erroneous buildings. The proposed framework was tested on three distinct urban areas in France with more than 3,000 buildings. 80%-99% F-score values are attained for the most frequent errors. For scalability purposes, the impact of the urban area composition on the error prediction was also studied, in terms of transferability, generalization, and representativeness of the classifiers. It shows the necessity of multi-modal remote sensing data and mixing training samples from various cities to ensure a stability of the detection ratios, even with very limited training set sizes. Note de contenu : 1- Introduction
2- State of the art
3- Semantic evaluation of 3D models
4- A learning approach for quality evaluation
5- Assessing the learned approach
6- Computing a better representation
7- Assessing the advanced features
8- ConclusionNuméro de notice : 25860 Affiliation des auteurs : LASTIG MATIS (2012-2019) Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Spécialité : Sciences et Technologies de l'Information Géographique : Paris-Est, 2019 Organisme de stage : Lastig (IGN) nature-HAL : Thèse DOI : sans En ligne : https://hal.science/tel-02879809 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95395 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 25860-02 THESE Livre Centre de documentation Thèses Disponible 25860-01 THESE Livre Centre de documentation Thèses Disponible 25860-03 THESE Livre Centre de documentation Thèses Disponible The necessary yet complex evaluation of 3D city models: a semantic approach / Oussama Ennafii (2019)
Titre : The necessary yet complex evaluation of 3D city models: a semantic approach Type de document : Article/Communication Auteurs : Oussama Ennafii , Auteur ; Clément Mallet , Auteur ; Arnaud Le Bris , Auteur ; Florent Lafarge, Auteur Editeur : New York : Institute of Electrical and Electronics Engineers IEEE Année de publication : 2019 Projets : 1-Pas de projet / Conférence : JURSE 2019, Joint Urban Remote Sensing Event 22/05/2019 24/05/2019 Vannes France Proceedings IEEE Importance : 4 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] compréhension de l'image
[Termes IGN] détection d'anomalie
[Termes IGN] image à très haute résolution
[Termes IGN] modèle 3D de l'espace urbain
[Termes IGN] précision sémantique
[Termes IGN] taxinomieRésumé : (Auteur) The automatic modeling of urban scenes in 3D from geospatial data has been studied for more than thirty years.However, the output models still have to undergo a tedious task of correction at city scale. In this work, we propose an approach for automatically evaluating the quality of 3D building models.A taxonomy of potential errors is first proposed. Handcrafted features are computed, based on the geometric properties of buildings and, when available, Very High Resolution images and depth data. They are fed into a Random Forest classifier for the prediction of the quality of the models. We tested our framework on three distinct urban areas in France. We can satisfactorily detect, on average 96% of the most frequent errors. Numéro de notice : C2019-001 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1109/JURSE.2019.8809002 Date de publication en ligne : 22/08/2019 En ligne : https://doi.org/10.1109/JURSE.2019.8809002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92103 Documents numériques
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