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Numérique versus symbolique : dialogue ontologique entre deux approches / Hélène Mathian in Revue internationale de géomatique, vol 31 n° 1-2 (janvier - juin 2022)
[article]
Titre : Numérique versus symbolique : dialogue ontologique entre deux approches Type de document : Article/Communication Auteurs : Hélène Mathian, Auteur ; Léna Sanders, Auteur Année de publication : 2022 Article en page(s) : pp 21 - 45 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse comparative
[Termes IGN] analyse de données
[Termes IGN] cadre conceptuel
[Termes IGN] établissement d'enseignement
[Termes IGN] Ile-de-France
[Termes IGN] ontologie
[Termes IGN] simulation dynamique
[Termes IGN] système multi-agentsRésumé : (Auteur) L’objectif de cet article est de comparer une approche statistique, l’analyse des données (AD) et une approche de simulation, les systèmes multi-agents (SMA). Ces deux familles de méthodes sont a priori considérées comme représentatives d’une approche numérique, respectivement symbolique, de la modélisation spatiale. Le cas d’application qui est mobilisé tout au long de l’article est celui de la ségrégation de l’espace scolaire en Île-de-France. En premier lieu sont explicitées et discutées les différentes étapes menant d’une question thématique à l’opérationnalisation d’une méthodologie d’analyse statistique ou de simulation destinée à analyser cette question. Pour effectuer cette comparaison, on développe un cadre conceptuel à l’interface entre les deux, qui permet de vérifier la compatibilité entre les arrières plans théoriques associés aux domaines thématiques et de modélisation en jeu. Ce cadre conceptuel prend appui sur une démarche ontologique qui est ensuite présentée. Celle-ci permet d’identifier les complémentarités entre AD et SMA et de montrer comment ces deux méthodes peuvent dialoguer dans le cadre d’une même recherche. Nous montrons combien les aspects numériques et symboliques sont finalement étroitement imbriqués au sein même de chacune de ces méthodes. Cette imbrication permet de construire une « spirale d’interactions » entre les deux familles de méthodes dont l’intérêt est illustré par les va et vient entre les phases d’analyse de structure et de simulation dynamique dans le cas de la ségrégation scolaire. Numéro de notice : A2022-807 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/MATHEMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : 10.3166/rig31.21-45 Date de publication en ligne : 06/12/2022 En ligne : https://doi.org/10.3166/rig31.21-45 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102219
in Revue internationale de géomatique > vol 31 n° 1-2 (janvier - juin 2022) . - pp 21 - 45[article]Optimization of deep neural networks: A functional perspective with applications in image classification / Simon Roburin (2022)
Titre : Optimization of deep neural networks: A functional perspective with applications in image classification Type de document : Thèse/HDR Auteurs : Simon Roburin, Auteur ; Mathieu Aubry, Directeur de thèse Editeur : Champs-sur-Marne : Ecole des Ponts ParisTech Année de publication : 2022 Importance : 141 p. Format : 21 x 30 cm Note générale : Bibliographie
Thèse de Doctorat de l'Ecole des Ponts ParisTech, spécialité Mathématiques AppliquéesLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse de groupement
[Termes IGN] apprentissage profond
[Termes IGN] classification par nuées dynamiques
[Termes IGN] mathématiques appliquées
[Termes IGN] optimisation (mathématiques)
[Termes IGN] vision par ordinateurIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Despite numerous successes in a wide range of industrial and scientific applications, the learning process of deep neural networks is poorly understood. Loosely speaking, learning aims at finding the network parameters that not only minimize the network errors on a set of training examples but also yield correct predictions on unseen data. Under the prism of optimization, it boils down to minimizing a high dimensional non-convex function. Generalization can generally be expected when one has access to very large datasets and assumes that both training examples and unseen data are sampled from identically independently distributed random variables. The goal of this thesis is to develop analytical tools to better understand neural network optimization and to improve the design of training algorithms in the context of image classification. Note de contenu : 1- Introduction
2- Literature review
3- Impact of Normalization Layers on Optimization
4- Avoid learning spurious correlations
5- ConclusionNuméro de notice : 24098 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Thèse française Note de thèse : Thèse de Doctorat : Mathématiques Appliquées : Ponts ParisTech : 2022 Organisme de stage : LIGM-IMAGINE En ligne : https://hal.science/tel-03968114v1 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102573 Photogrammetric point clouds: quality assessment, filtering, and change detection / Zhenchao Zhang (2022)
Titre : Photogrammetric point clouds: quality assessment, filtering, and change detection Type de document : Thèse/HDR Auteurs : Zhenchao Zhang, Auteur ; M. George Vosselman, Auteur ; Markus Gerke, Auteur ; Michael Ying Yang, Auteur Editeur : Enschede [Pays-Bas] : International Institute for Geo-Information Science and Earth Observation ITC Année de publication : 2022 Note générale : bibliographie
NB : EMBARGO SUR LE TEXTE JUSQU'AU 1ER JUILLET 2022Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] appariement dense
[Termes IGN] détection de changement
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] qualité des données
[Termes IGN] réseau neuronal convolutif
[Termes IGN] segmentation sémantique
[Termes IGN] semis de pointsRésumé : (auteur) 3D change detection draws more and more attention in recent years due to the increasing availability of 3D data. It can be used in the fields of land use / land cover (LULC) change detection, 3D geographic information updating, terrain deformation analysis, urban construction monitoring et al. Our motivation to study 3D change detection is mainly related to the practical need to update the outdated point clouds captured by Airborne Laser Scanning (ALS) with new point clouds obtained by dense image matching (DIM).
The thesis has three main parts. The first part, chapter 1, explains the motivation, providing a review of current ALS and airborne photogrammetry techniques. It also presents the research objectives and questions. The second part including chapter 2 and chapter 3 evaluates the quality of photogrammetric products and investigates their potential for change detection. The third part including chapter 4 and chapter 5 proposes two methods for change detection that meet different requirements.
To investigate the potential of using point clouds derived by dense matching for change detection, we propose a framework for evaluating the quality of 3D point clouds and DSMs generated by dense image matching. Our evaluation framework based on a large number of square patches reveals the distribution of dense matching errors in the whole photogrammetric block. Robust quality measures are proposed to indicate the DIM accuracy and precision quantitatively. The overall mean offset to the reference is 0.1 Ground Sample Distance (GSD); the maximum mean deviation reaches 1.0 GSD. We also find that the distribution of dense matching errors is homogenous in the whole block and close to a normal distribution based on many patch-based samples. However, in some locations, especially along narrow alleys, the mean deviations may get worse. In addition, the profiles of ALS points and DIM points reveal that the DIM profile fluctuates around the ALS profile. We find that the accuracy of DIM point cloud improves and that the noise level decreases on smooth ground areas when oblique images are used in dense matching together with nadir images.
Then we evaluate whether the standard LiDAR filters are effective to filter dense matching points in order to derive accurate DTMs. Filtering results on a city block show that LiDAR filters perform well on the grassland, along bushes and around individual trees if the point cloud is sufficiently precise. When a ranking filter is used on the point clouds before filtering, the filtering will identify fewer but more reliable ground points. However, some small objects on the terrain will be filtered out. Since we aim at obtaining accurate DTMs, the ranking filter shows its value in identifying reliable ground points. Based on the previous findings in DIM quality, we propose a method to detect building changes between ALS and photogrammetric data. Firstly, the ALS points and DIM points are split out and concatenated with the orthoimages. The multimodal data are normalized to feed into a pseudo-Siamese Neural network for change detection. Then, the changed objects are delineated through per-pixel classification and artefact removal. The change detection module based on a pseudo-Siamese CNN can quickly localize the changes and generate coarse change maps. The next module can be used in precise mapping of change boundaries. Experimental results show that the proposed pseudo-Siamese Neural network can cope with the DIM errors and output plausible change detection results. Although the point cloud quality from dense matching is not as fine as laser scanning points, the spectral and textural information provided by the orthoimages serve as a supplement.
Considering that the tasks of semantic segmentation and change detection are correlated, we propose SiamPointNet++ model to combine the two tasks in one framework. The method outputs a pointwise joint label for each ALS point. If an ALS point is unchanged, it is assigned a semantic label; If an ALS point is changed, it is assigned a change label. The sematic and change information are included in the joint labels with minimum information redundancy. The combined Siamese network learns both intra-epoch and inter-epoch features. Intra-epoch features are extracted at multiple scales to embed the local and global information. Inter-epoch features are extracted by Conjugated Ball Sampling (CBS) and concatenated to make change inference. Experiments on the Rotterdam data set indicate that the network is effective in learning multi-task features. It is invariant to the permutation and noise of inputs and robust to the data difference between ALS and DIM data. Compared with a sophisticated object-based method and supervised change detection, this method requires much less hyper-parameters and human intervention but achieves superior performance.
As a conclusion, the thesis evaluates the quality of dense matching points and investigates its potential of updating outdated ALS points. The two change detection methods developed for different applications show their potential in the automation of topographic change detection and point cloud updating. Future work may focus on improving the generalizability and interpretability of the proposed models.Numéro de notice : 20403 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Thèse étrangère Note de thèse : PhD thesis : Geo-Information Science and Earth Observation : Enschede, university of Twente : 2022 DOI : 10.3990/1.9789036552653 Date de publication en ligne : 14/01/2022 En ligne : https://research.utwente.nl/en/publications/photogrammetric-point-clouds-quality [...] Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100963 Predicting AIS reception using tropospheric propagation forecast and machine learning / Zackary Vanche (2022)
Titre : Predicting AIS reception using tropospheric propagation forecast and machine learning Type de document : Article/Communication Auteurs : Zackary Vanche, Auteur ; Ambroise Renaud, Auteur ; Aldo Napoli, Auteur Editeur : New York : Institute of Electrical and Electronics Engineers IEEE Année de publication : 2022 Projets : 2-Pas d'info accessible - article non ouvert / Conférence : ISAP 2022, IEEE AP-S/USNC-URSI International Symposium on Antennas & Propagation 10/07/2022 Denver Colorado - Etats-Unis Proceedings IEEE Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] apprentissage automatique
[Termes IGN] carte thématique
[Termes IGN] identification automatique
[Termes IGN] navigation maritime
[Termes IGN] navire
[Termes IGN] récepteur
[Termes IGN] troposphèreRésumé : (auteur) The aim of this paper is to present a methodology for modelling and predicting the coverage of an Automatic Identification System (AIS) station based on tropospheric index forecast maps and modelling methods from machine learning. The aim of this work is to cartographically represent the areas in which the AIS signals emitted by ships will be received by a coastal station. This work contributes to the improvement of maritime situational awareness and to the detection of anomalies at sea [1], and in particular to the identification of AIS message falsifications [2] (ubiquity of a vessel by identity theft, falsification of GPS positions and deactivation of AIS). Numéro de notice : C2022-036 Affiliation des auteurs : ENSG+Ext (2020- ) Autre URL associée : vers HAL Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.23919/USNC-URSI52669.2022.9887465 En ligne : https://doi.org/10.23919/USNC-URSI52669.2022.9887465 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101606 A prediction model for surface deformation caused by underground mining based on spatio-temporal associations / Min Ren in Geomatics, Natural Hazards and Risk, vol 13 (2022)
[article]
Titre : A prediction model for surface deformation caused by underground mining based on spatio-temporal associations Type de document : Article/Communication Auteurs : Min Ren, Auteur ; Guanwen Cheng, Auteur ; Wancheng Zhu, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 94 - 122 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse des risques
[Termes IGN] analyse spatio-temporelle
[Termes IGN] Chine
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] déformation de la croute terrestre
[Termes IGN] déformation de surface
[Termes IGN] mine de fer
[Termes IGN] modèle de simulation
[Termes IGN] règle d'associationMots-clés libres : spatio-temporal association rule mining (STARM) Résumé : (auteur) Accurate predictions of the surface deformation caused by underground mining are crucial for the safe development of underground resources. Although surface deformation has been predicted by artificial intelligence (AI) methods, most AI models are established based on the relationships between surface deformation and influential factors. The lack of consideration of the deformation state transition often leads to errors in the prediction results of catastrophic deformation by conventional AI methods. In this respect, this study introduces a surface deformation prediction model based on spatio-temporal association rule mining (STARM). Surface deformation is classified as excessive deformation zone (EDZ) and hysteretic deformation zone (HDZ), representing different surface deformation stage or state. The spatio-temporal association rules between the monitored EDZ and HDZ data are then mined. A surface deformation prediction model is established according to the spatio-temporal relationship between monitored EDZ and HDZ data. The proposed model is verified based on a practical case study of the Chengchao Iron Mine in China. The data collection of the influential factors is not requisite for the proposed model. It can achieve accurate prediction of the catastrophic deformation that was characterized by deformation state transition. Numéro de notice : A2022-035 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article DOI : 10.1080/19475705.2021.2015460 Date de publication en ligne : 21/12/2021 En ligne : https://doi.org/10.1080/19475705.2021.2015460 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99359
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