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Unsupervised deep representation learning for real-time tracking / Ning Wang in International journal of computer vision, vol 129 n° 2 (February 2021)
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Titre : Unsupervised deep representation learning for real-time tracking Type de document : Article/Communication Auteurs : Ning Wang, Auteur ; Wengang Zhou, Auteur ; Yibing Song, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 400 - 418 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] appariement d'images
[Termes IGN] apprentissage profond
[Termes IGN] classification non dirigée
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] détection de cible
[Termes IGN] filtre
[Termes IGN] objet mobile
[Termes IGN] oculométrie
[Termes IGN] reconnaissance d'objets
[Termes IGN] réseau neuronal siamois
[Termes IGN] temps réel
[Termes IGN] traçage
[Termes IGN] trajectoire (véhicule non spatial)
[Termes IGN] vision par ordinateurRésumé : (auteur) The advancement of visual tracking has continuously been brought by deep learning models. Typically, supervised learning is employed to train these models with expensive labeled data. In order to reduce the workload of manual annotation and learn to track arbitrary objects, we propose an unsupervised learning method for visual tracking. The motivation of our unsupervised learning is that a robust tracker should be effective in bidirectional tracking. Specifically, the tracker is able to forward localize a target object in successive frames and backtrace to its initial position in the first frame. Based on such a motivation, in the training process, we measure the consistency between forward and backward trajectories to learn a robust tracker from scratch merely using unlabeled videos. We build our framework on a Siamese correlation filter network, and propose a multi-frame validation scheme and a cost-sensitive loss to facilitate unsupervised learning. Without bells and whistles, the proposed unsupervised tracker achieves the baseline accuracy of classic fully supervised trackers while achieving a real-time speed. Furthermore, our unsupervised framework exhibits a potential in leveraging more unlabeled or weakly labeled data to further improve the tracking accuracy. Numéro de notice : A2021-353 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article DOI : 10.1007/s11263-020-01357-4 Date de publication en ligne : 21/09/2020 En ligne : https://doi.org/10.1007/s11263-020-01357-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97604
in International journal of computer vision > vol 129 n° 2 (February 2021) . - pp 400 - 418[article]Mapping seasonal agricultural land use types using deep learning on Sentinel-2 image time series / Misganu Debella-Gilo in Remote sensing, Vol 13 n° 2 (January-2 2021)
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Titre : Mapping seasonal agricultural land use types using deep learning on Sentinel-2 image time series Type de document : Article/Communication Auteurs : Misganu Debella-Gilo, Auteur ; Arnt Kristian Gjertsen, Auteur Année de publication : 2021 Article en page(s) : n° 289 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] apprentissage automatique
[Termes IGN] carte agricole
[Termes IGN] carte d'utilisation du sol
[Termes IGN] classification par Perceptron multicouche
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] image Sentinel-MSI
[Termes IGN] Norvège
[Termes IGN] série temporelle
[Termes IGN] Soil Adjusted Vegetation Index
[Termes IGN] surface cultivée
[Termes IGN] utilisation du sol
[Termes IGN] variation saisonnièreRésumé : (auteur) The size and location of agricultural fields that are in active use and the type of use during the growing season are among the vital information that is needed for the careful planning and forecasting of agricultural production at national and regional scales. In areas where such data are not readily available, an independent seasonal monitoring method is needed. Remote sensing is a widely used tool to map land use types, although there are some limitations that can partly be circumvented by using, among others, multiple observations, careful feature selection and appropriate analysis methods. Here, we used Sentinel-2 satellite image time series (SITS) over the land area of Norway to map three agricultural land use classes: cereal crops, fodder crops (grass) and unused areas. The Multilayer Perceptron (MLP) and two variants of the Convolutional Neural Network (CNN), are implemented on SITS data of four different temporal resolutions. These enabled us to compare twelve model-dataset combinations to identify the model-dataset combination that results in the most accurate predictions. The CNN is implemented in the spectral and temporal dimensions instead of the conventional spatial dimension. Rather than using existing deep learning architectures, an autotuning procedure is implemented so that the model hyperparameters are empirically optimized during the training. The results obtained on held-out test data show that up to 94% overall accuracy and 90% Cohen’s Kappa can be obtained when the 2D CNN is applied on the SITS data with a temporal resolution of 7 days. This is closely followed by the 1D CNN on the same dataset. However, the latter performs better than the former in predicting data outside the training set. It is further observed that cereal is predicted with the highest accuracy, followed by grass. Predicting the unused areas has been found to be difficult as there is no distinct surface condition that is common for all unused areas. Numéro de notice : A2021-198 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.3390/rs13020289 Date de publication en ligne : 15/01/2021 En ligne : https://doi.org/10.3390/rs13020289 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97149
in Remote sensing > Vol 13 n° 2 (January-2 2021) . - n° 289[article]
Titre : 3D object detection using lidar point clouds and 2D image object detection Type de document : Mémoire Auteurs : Topi Miekkala, Auteur Editeur : Tampere [Finlande] : Tampere University Année de publication : 2021 Importance : 67 p. Format : 21 x 30 cm Note générale : bibliographie
Master of Science Thesis, Automation EngineeringLangues : Français (fre) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] apprentissage profond
[Termes IGN] détection d'objet
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] fusion de données
[Termes IGN] image 2D
[Termes IGN] navigation autonome
[Termes IGN] objet 3D
[Termes IGN] piéton
[Termes IGN] point d'intérêt
[Termes IGN] segmentation
[Termes IGN] semis de points
[Termes IGN] temps réel
[Termes IGN] vision par ordinateurRésumé : (auteur) This master thesis is about the environmental sensing of an automated vehicle, and its ability to recognize objects of interest such as other road users including pedestrians and other vehicles. Automated driving is a popular and growing field of research, and the continuous increase in the demand of self-driving vehicles requires manufacturers to constantly improve the safety and environmental sensing capabilities of their vehicles. Deep learning neural networks and sensor data fusion are significant tools in the development of detection algorithms of automated vehicles. This thesis presents a method combining neural networks and sensor data fusion to implement 3D object detection into a self-driving car. The method uses an onboard camera sensor and a state of the art 2D image object detector YOLO v4, combining its detections with the data of a lidar sensor, which produces dense point clouds of its environment. These point clouds can be used to estimate distances and locations of surrounding targets. Using inter-sensor calibration between the camera and the lidar, the 3D points outputted by the lidar can be projected on a 2D image, therefore allowing the 3D location estimation of 2D objects detected in an image. The thesis first presents the research questions and the theoretical methods used to implement the algorithm. Some background on automated driving is also presented, followed by the specific research environment and vehicle used in this thesis. The thesis also presents the software implementations and vehicle system integration steps needed to implement everything into a self-driving car to achieve a real-time 3D object detection system. The results of this thesis show that using sensor data fusion, such a system can be integrated fully into a self-driving vehicle, and the processing times of the algorithm can be kept at a real-time rate. Note de contenu : 1- Introduction
2- Methods for sensor data and object detection
3- Autonomous driving and environmental sensing
4- Experiments
5- Evaluation
6- ConclusionNuméro de notice : 28594 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Mémoire masters divers En ligne : https://trepo.tuni.fi/handle/10024/132285 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99323 3D urban scene understanding by analysis of LiDAR, color and hyperspectral data / David Duque-Arias (2021)
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Titre : 3D urban scene understanding by analysis of LiDAR, color and hyperspectral data Type de document : Thèse/HDR Auteurs : David Duque-Arias, Auteur ; Beatriz Marcotegui, Directeur de thèse ; Jean-Emmanuel Deschaud, Directeur de thèse Editeur : Paris : Université Paris Sciences et Lettres Année de publication : 2021 Importance : 191 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse de Doctorat de l'Université PSL, Spécialité : Morphologie MathématiqueLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] analyse de scène 3D
[Termes IGN] apprentissage profond
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] graphe
[Termes IGN] image hyperspectrale
[Termes IGN] image optique
[Termes IGN] modélisation géométrique de prise de vue
[Termes IGN] monde virtuel
[Termes IGN] morphologie mathématique
[Termes IGN] navigation autonome
[Termes IGN] scène urbaine
[Termes IGN] segmentation sémantique
[Termes IGN] semis de points
[Termes IGN] traitement d'imageIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Point clouds have attracted the interest of the research community over the last years. Initially, they were mostly used for remote sensing applications. More recently, thanks to the development of low-cost sensors and the publication of some open source libraries, they have become very popular and have been applied to a wider range of applications. One of them is the autonomous vehicle where many efforts have been made in the last century to make it real. A very important bottleneck nowadays for the autonomous vehicle is the evaluation of the proposed algorithms. Due to the huge number of possible scenarios, it is not feasible to perform it in real life. An alternative is to simulate virtual environments where all possible configurations can be set up beforehand. However, they are not as realistic as the real world is. In this thesis, we studied the pertinence of including hyperspectral images in the creation of new virtual environments. Furthermore, we proposed new methods to improve 3D scene understanding for autonomous vehicles. During this research, we addressed the following topics. Firstly, we analyzed the spectrum in color and hyperspectral images because it provides a description about the electromagnetic radiation at different frequencies. Some applications rely only on visible colors. In other cases, such as the characterization of materials, the study of the invisible range is required. For this purpose, we proposed a simplified spectrum representation that preserves its diversity, the Graph-based color lines (GCL) model. Secondly, we studied the integration of hyperspectral images, color images and point clouds in urban scenes. The analysis was carried out by using the data acquired during this thesis in the context of the REPLICA project FUI 24. We inspected spectral signatures of different objects and reflectance histograms of the images. The obtained results demonstrate that urban scenes are challenging scenarios for current technology of hyperspectral cameras due to the presence of uncontrolled light conditions and moving actors. Thirdly, we worked with 3D point clouds from urban scenes that have proved to be a reliable type of data, much less sensitive to illumination variations than cameras. They are more accurate than color images and permit to obtain precise 3D models of urban environments. Deep learning techniques are very popular in this domain. A key element of these techniques is the loss function that drives the optimization process. We proposed two new loss functions to perform semantic segmentation tasks: power Jaccard loss and hierarchical loss. They obtained a higher performance in evaluated scenarios than classical losses not only in 3D point clouds but also in color and gray scale images. Moreover, we proposed a new dataset (Paris Carla 3D Dataset) composed of synthetic and real point clouds from urban scenes. It is expected to be used by the research community for different automatic tasks such as semantic segmentation, instance segmentation and scene completion. Finally, we conducted a detailed analysis of the influence of RGB features in semantic segmentation of urban point clouds. We compared several training scenarios and identified that color systematically improves the performance in certain classes. It demonstrates that including a more detailed description of the spectrum, when the hyperspectral cameras technology increases its sensitivity, can be useful to improve scene description of urban scenes. Note de contenu : 1- Introduction
2- Data used in this thesis
3- Graph based color lines (GCL)
4- Study of REPLICA data
5- Power Jaccard losses for semantic segmentation
6- Segmentation of point clouds
7- Conclusions and perspectivesNuméro de notice : 28464 Affiliation des auteurs : non IGN Thématique : IMAGERIE/MATHEMATIQUE/URBANISME Nature : Thèse française Note de thèse : Thèse de Doctorat : Morphologie Mathématique : Paris sciences et lettres : 2021 Organisme de stage : Centre de Morphologie Mathématique DOI : sans En ligne : https://pastel.hal.science/tel-03434199/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99076
Titre : Advances in modeling and management of urban water networks Type de document : Monographie Auteurs : Enrico Creaco, Éditeur scientifique ; Alberto Campisano, Éditeur scientifique Editeur : Bâle [Suisse] : Multidisciplinary Digital Publishing Institute MDPI Année de publication : 2021 Importance : 290 p. Format : 16 x 24 cm ISBN/ISSN/EAN : 978-3-03943-790-0 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] algorithme génétique
[Termes IGN] canalisation
[Termes IGN] eau pluviale
[Termes IGN] écoulement des eaux
[Termes IGN] gestion de l'eau
[Termes IGN] modèle de simulation
[Termes IGN] modèle hydrographique
[Termes IGN] optimisation (mathématiques)
[Termes IGN] planification urbaine
[Termes IGN] réseau d'assainissement
[Termes IGN] réseau de distribution d'eau
[Termes IGN] réseau de drainage
[Termes IGN] réseau neuronal artificiel
[Termes IGN] réseau technique urbain
[Termes IGN] système d'information géographiqueRésumé : (éditeur) The Special Issue on Advances in Modeling and Management of Urban Water Networks (UWNs) explores four important topics of research in the context of UWNs: asset management, modeling of demand and hydraulics, energy recovery, and pipe burst identification and leakage reduction. In the first topic, the multi-objective optimization of interventions on the network is presented to find trade-off solutions between costs and efficiency. In the second topic, methodologies are presented to simulate and predict demand and to simulate network behavior in emergency scenarios. In the third topic, a methodology is presented for the multi-objective optimization of pump-as-turbine (PAT) installation sites in transmission mains. In the fourth topic, methodologies for pipe burst identification and leakage reduction are presented. As for the urban drainage systems (UDSs), the two explored topics are asset management, with a system upgrade to reduce flooding, and modeling of flow and water quality, with analyses on the transition from surface to pressurized flow, impact of water use reduction on the operation of UDSs, and sediment transport in pressurized pipes. The Special Issue also includes one paper dealing with the hydraulic modeling of an urban river with a complex cross-section. Note de contenu : 1- Advances in modeling and management of urban water networks
2- Cost–benefit prediction of asset management actions on water distribution networks
3- Nonlinear dynamic modeling of urban water consumption using chaotic approach (case study: City of Kelowna)
4- Hydraulic simulation and analysis of an urban center’s aqueducts using emergency scenarios for network operation: The case of Thessaloniki city in Greece
5- A bi-objective approach for optimizing the installation of PATs in systems of transmission mains
6- Geospatial information system-based modeling approach for leakage management in urban water distribution networks
7- Pattern recognition and clustering of transient pressure signals for burst location
8- Application of rehabilitation and active pressure control strategies for leakage reduction in a case-study network
9- An improved genetic algorithm for optimal layout of flow meters and valves in water network partitioning
10- Urban drainage network rehabilitation considering storm tank installation and pipe substitution
11- Multi-objective optimization for urban drainage or sewer networks rehabilitation through pipes substitution and storage tanks installation
12- Suppress numerical oscillations in transient mixed flow simulations with a modified HLL solver
13- A stochastic model to predict flow, nutrient and temperature changes in a sewer under water conservation scenarios
14- Sediment transport in sewage pressure pipes, Part I: Continuous determination of settling and erosion characteristics by in-situ TSS monitoring inside a pressure pipe in Northern Germany
15- Sediment transport in sewage pressure pipes, Part II: 1 D numerical simulation
16- Simulating flow of an urban river course with complex cross sections based on the MIKE21 FM modelNuméro de notice : 28446 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Recueil / ouvrage collectif DOI : 10.3390/books978-3-03943-790-0 En ligne : https://doi.org/10.3390/books978-3-03943-790-0 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98913 Aleatoric uncertainty estimation for dense stereo matching via CNN-based cost volume analysis / Max Mehltretter in ISPRS Journal of photogrammetry and remote sensing, vol 171 (January 2021)
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