19 research outputs found
Comparison of convolutional neural networks for cloudy optical images reconstruction from single or multitemporal joint SAR and optical images
With the increasing availability of optical and synthetic aperture radar
(SAR) images thanks to the Sentinel constellation, and the explosion of deep
learning, new methods have emerged in recent years to tackle the reconstruction
of optical images that are impacted by clouds. In this paper, we focus on the
evaluation of convolutional neural networks that use jointly SAR and optical
images to retrieve the missing contents in one single polluted optical image.
We propose a simple framework that ease the creation of datasets for the
training of deep nets targeting optical image reconstruction, and for the
validation of machine learning based or deterministic approaches. These methods
are quite different in terms of input images constraints, and comparing them is
a problematic task not addressed in the literature. We show how space
partitioning data structures help to query samples in terms of cloud coverage,
relative acquisition date, pixel validity and relative proximity between SAR
and optical images. We generate several datasets to compare the reconstructed
images from networks that use a single pair of SAR and optical image, versus
networks that use multiple pairs, and a traditional deterministic approach
performing interpolation in temporal domain.Comment: 17 page
Les contrats de bancs d'église à Montréal au XVIIIe siÚcle (1692-1760)
Nous avons divisé notre travail en quatre grandes parties. La premiÚre partie à caractÚre descriptif, nous permettra de présenter les paroisses. En effet, nous croyons qu'il est important de connaßtre le cadre physique et administratif dans lequel s'effectue la concession des bancs. Dans la deuxiÚme partie, nous présenterons les principaux documents qui ont servi de base à notre travail. Dans le chapitre suivant, nous nous interrogerons sur le sens de la concession des bancs; nous examinerons les rÚglements relatifs à cette pratique et surtout nous étudierons l'application de ceux-ci. Enfin, grùce à une analyse quantitative nous tenterons de cerner les facteurs socio-économiques susceptibles d'expliquer les motivations qui poussent le Canadien à posséder un banc dans son église paroissiale. Car l'insistance des autorités tant civiles que religieuses à régir la distribution des bancs, leur prix et leur position dans l'église sont, croyons-nous, autant d'indices qui peuvent nous révéler l'importance que la société canadienne du XVIIIe siÚcle attachait à la place de banc dans l'église paroissiale. Dans cette perspective, notre travail consiste moins à souligner l'origine et les lois qui régissent la concession des bancs dans les églises qu'à décrire et à analyser les différents contrats de concession de banc. Dans la mesure ou les documents utilisés nous le permettent, nous dégagerons les implications sociales et économiques de cette coutume
Sentiment de prĂ©sence et symptĂŽmes de cybermalaise dans une population dâenfants souffrant de maux de tĂȘte chroniques immergĂ©s en rĂ©alitĂ© virtuelle
Introduction : Le sentiment de prĂ©sence et le cybermalaise sont des concepts clĂ© en rĂ©alitĂ© virtuelle. Le sentiment de prĂ©sence, câest-Ă -dire la sensation psychologique dâĂȘtre dans lâenvironnement virtuel distingue la rĂ©alitĂ© virtuelle dâautres distractions possibles. La rĂ©alitĂ© virtuelle peut Ă©galement causer des symptĂŽmes de cybermalaise qui sâapparentent aux malaises dus au mal des transports. Ces deux concepts sont des mĂ©canismes sous-jacents au fonctionnement thĂ©rapeutique de la rĂ©alitĂ© virtuelle. TrĂšs peu dâĂ©tudes ont Ă©tudiĂ© lâefficacitĂ© de la rĂ©alitĂ© virtuelle sur le sentiment de prĂ©sence et les cybermalaises des enfants, dâoĂč lâintĂ©rĂȘt de notre Ă©tude. Quâen est-il de ces deux aspects lorsque le rĂ©alitĂ© virtuelle est combinĂ©e Ă un appareillage de biofeedback?
MĂ©thodologie : Un Ă©chantillon de 10 enfants ont complĂ©tĂ© diffĂ©rents questionnaires permettant de mesurer leur sentiment de prĂ©sence aprĂšs lâimmersion et les symptĂŽmes de cybermalaise avant et aprĂšs lâimmersion. Cette Ă©tude sâinscrit dans une Ă©tude plus large qui consiste Ă tester le dĂ©veloppement de compĂ©tences de relaxation chez des enfants migraineux via une intervention en rĂ©alitĂ© virtuelle combinĂ©e Ă un appareillage de biofeedback. L'intervention s'est dĂ©roulĂ© une fois par semaine pendant 8 semaines. Pendant chaque sĂ©ance, l'enfant s'exerçait Ă utiliser la technique de relaxation en rĂ©alitĂ© virtuelle.
Résultats : Les moyennes du sentiment de présence des différents environnements sont satisfaisantes. Les différences des moyennes de cybermalaise avant et aprÚs immersion sont significatives mais les moyennes observées restent cependant basses.
Discussion : Lâutilisation de la rĂ©alitĂ© virtuelle couplĂ©e Ă un appareillage de biofeedback, dans une population dâenfants migraineux, semble adĂ©quate au niveau du sentiment de prĂ©sence et de cybermalaise
Comparison of convolutional neural networks for cloudy optical images reconstruction from single or multitemporal joint SAR and optical images
International audienceWith the increasing availability of optical and synthetic aperture radar (SAR) images thanks to the Sentinel constellation, and the explosion of deep learning, new methods have emerged in recent years to tackle the reconstruction of optical images that are impacted by clouds. In this paper, we focus on the evaluation of convolutional neural networks that use jointly SAR and optical images to retrieve the missing contents in one single polluted optical image. We propose a simple framework that ease the creation of datasets for the training of deep nets targeting optical image reconstruction, and for the validation of machine learning based or deterministic approaches. These methods are quite different in terms of input images constraints, and comparing them is a problematic task not addressed in the literature. We show how space partitioning data structures help to query samples in terms of cloud coverage, relative acquisition date, pixel validity and relative proximity between SAR and optical images. We generate several datasets to compare the reconstructed images from networks that use a single pair of SAR and optical image, versus networks that use multiple pairs, and a traditional deterministic approach performing interpolation in temporal domain
Improving adhesion of powder coating on PEEK composite: Influence of atmospheric plasma parameters
International audienceIn aeronautic industries, powder coatings are increasingly used because of environmental considerations. During the deposition of such a coating on a substrate piece, the main objective is to obtain a good coating/substrate adhesion. In this study, the targeted substrate is a Poly-(Ether EtherKetone)-(PEEK) based composite material. Due to the poor surface energy of PEEK, a surface treatment is necessary in order to enhance its adhesion with the coating. In this purpose, atmospheric plasma treatment has been chosen and the influence of plasma parameters has been studied. Four scan speed nozzles and three gases (Air, N2 and Argon) plasma has been tested. The increase of adhesion with increasing wettability, polarity and nanoroughness has been evidenced. A particular study of the type of grafted polar functionalities according to gas nature allowed to better understand the plasma mechanism and the cross-impact of polarity and nanoroughness in adhesion enhancement
Brief communication: Evaluation of the snow cover detection in the Copernicus High Resolution Snow & Ice Monitoring Service
International audienceThe High Resolution Snow & Ice Monitoring Service was launched in 2020 to provide near-real-time, pan-European snow and ice information at 20 m resolution from Sentinel-2 observations. Here we present an evaluation of the snow detection using a database of snow depth observations from 1764 stations across Europe over the hydrological year 2016-2017. We find a good agreement between both datasets with an accuracy (proportion of correct classifications) of 94 % and kappa of 0.81. More accurate (+6 % kappa) retrievals are obtained by excluding low-quality pixels at the cost of a reduced coverage (-13 % data)
Pathogenic and likely pathogenic variants in at least five genes account for approximately 3% of mild isolated nonsyndromic thrombocytopenia
International audienceBackground: Thrombocytopenia has a variety of different etiologies, both acquired and hereditary. Inherited thrombocytopenia may be associated with other symptoms (syndromic forms) or may be strictly isolated. To date, only about half of all the familial forms of thrombocytopenia have been accounted for in terms of well-defined genetic abnormalities. However, data are limited on the nature and frequency of the underlying causative genetic variants in individuals with mild isolated nonsyndromic thrombocytopenia.Study design and methods: Thirteen known or candidate genes for isolated thrombocytopenia were included in a gene panel analysis in which targeted next-generation sequencing was performed on 448 French blood donors with mild isolated nonsyndromic thrombocytopenia.Results: A total of 68 rare variants, including missense, splice site, frameshift, nonsense, and in-frame variants (all heterozygous) were identified in 11 of the 13 genes screened. Twenty-nine percent (N = 20) of the variants detected were absent from both the French Exome Project and gnomAD exome databases. Using stringent criteria and an unbiased approach, we classified seven predicted loss-of-function variants (three in ITGA2B and four in TUBB1) and four missense variants (one in GP1BA, two in ITGB3 and one in ACTN1) as being pathogenic or likely pathogenic. Altogether, they were found in 13 members (approx. 3%) of our studied cohort.Conclusion: We present the results of gene panel sequencing of known and candidate thrombocytopenia genes in mild isolated nonsyndromic thrombocytopenia. Pathogenic and likely pathogenic variants in five known thrombocytopenia genes were identified, accounting for approximately 3% of individuals with the condition