Study of the Non-negative Matrix Factorization behavior to estimate the urban traffic sound levels

ICSV'26 ; 26ème International Congress on Sound and Vibration , MONTREAL, CANADA, 11-/07/2019 - 17/07/2019The advent of low-cost acoustic sensor networks in cities raises new interesting approaches for improving the monitoring of the acoustic quality of cities. Many innovative approaches are developed to improve knowledge on sound environments: sound environment recognition, sound source detection, etc. In order to improve the road traffic noise mapping, the use of a specific version of the Non-negative Matrix Factorization (NMF), named thresholded initialized NMF, as a source separation method to estimate the sound level of road traffic from measurements, has proved to be a successful approach. This paper proposes to further detail the functioning of the thresholded initialized NMF on a corpus composed of urban sound scenes mixing traffic and specific interfering components with calibrated sound levels in order to better understand its behavior according to the different sources encountered. The study reveals the different performances of this approach depending on the noise levels of the interfering sources and their proximity to the urban traffic spectrum

Les professeurs-stagiaires d’IUFM et les technologies

Cette recherche étudie l’appropriation des TICE et les premiers usages par les stagiaires des IUFM. Cette population est généralement équipée et a bénéficié d’une formation à l’Université et à l’IUFM. L’objectif était de savoir si ces conditions sont suffisantes pour que des usages professionnels se développent ou si des obstacles subsistent. À partir de questionnaires et d’analyse de mémoires, nous mettons en évidence une instrumentation limitée, des pratiques collaboratives faibles et des difficultés à utiliser des logiciels spécifiques aux disciplines.This research studies the learning of ICT (Information and Communications technology) and their first use by teacher trainees. This population is generally equipped and has benefited from a training at university and at the IUFM (teacher training university institute). The goal was to know if these conditions are sufficient to favour the development of professional use or if there remain obstacles. Some questionnaires and an analysis of students’ dissertations have revealed a limited instrumentation, poor collaborative practices and some difficulties in using software specific to subjects.Esta investigación estudia la apropiación de las TICE y los primeros usos por los cursillistas de los IUFM. Esta población es generalmente dotada y se ha beneficiado de una formación en la Universidad y en el IUFM. El objetivo era saber si estas condiciones son suficientes para que se desarrollen usos profesionales o si subsisten obstáculos. A partir de cuestionarios y de análisis de memorias ponemos en evidencia una instrumentación limitada, prácticas colaborativas escasas y dificultades para utilizar logiciales específicos a las disciplinas.Diese Untersuchung analysiert, wie die Referendare der PH sich die I-und K-Technologien aneignen und benutzen. Diese Bevölkerungsgruppe ist im Allgemeinen ausgerüstet und wurde an der Universität und an der PH ausgebildet. Das Ziel bestand darin, zu wissen, ob diese Bedingungen reichten, damit eine berufliche Benutzung sich entwickelt oder ob Hindernisse bestehen.Ausgehend von Fragebogen und Analysen von Examsarbeiten stellen wir eine begrenzte Instrumentation, ein geringes Teamwork und Schwierigkeiten, fachspezifische Softwares zu benutzen, klar

Estimation du niveau sonore du trafic routier au sein de mixtures sonores urbaines par la Factorisation en Matrices Non négatives

14ème congrès français d'acoustique, CFA'18, LE HAVRE, FRANCE, 23-/04/2018 - 27/04/2018La création de cartes de bruit de trafic en ville, imposée par la directive européenne 2002/49/EC, est issue d'un processus de simulation basé sur un modèle du tissu urbain et des outils de propagation acoustiques. Ces cartes sont purement prédictives et ne sont disponibles que pour des échelles de temps très larges, ce qui ne permet pas de rendre compte correctement de l'évolution permanente du trafic routier. Le déploiement actuel de réseaux de capteurs acoustiques en ville, dans le cadre des « Smart Cities », est l'opportunité d'améliorer ces cartes en complétant les données simulées par des données mesurées in situ. L'utilisation d'une méthode de séparation de sources est néanmoins nécessaire pour extraire des enregistrements la composante signal « trafic » des autres sources sonores présentes en ville. La méthode retenue ici pour ce faire est la Factorisation en Matrices Non-Négatives (NMF) qui présente l'avantage de prendre en compte naturellement le recouvrement des nombreuses sources sonores qui composent l'environnement sonore urbain. Une fois ce signal trafic extrait, son niveau sonore peut être estimé. La méthode est testée sur un ensemble de scènes sonores simulées générées à partir d'annotations d'enregistrements faits en ville. Cette approche permet de disposer d'une mesure étalon qui est comparée aux estimations générées par différentes configurations de la NMF. Les résultats obtenus montrent que la méthode NMF offre de meilleurs résultats que des approches de références basées sur des filtres et peut faire l'objet d'une implantation future au sein de réseaux de capteurs intelligents

Superconductivity in Li3Ca2C6 intercalated graphite

In this letter, we report the discovery of superconductivity in Li3Ca2C6. Several graphite intercalation compounds (GICs) with electron donors, are well known as superconductors. It is probably not astonishing, since it is generally admitted that low dimensionality promotes high superconducting transition temperatures. Superconductivity is lacking in pristine graphite, but after charging the graphene planes by intercalation, its electronic properties change considerably and superconducting behaviour can appear. Li3Ca2C6 is a ternary GIC, for which the intercalated sheets are very thick and poly-layered (five lithium layers and two calcium ones). It contains a great amount of metal (five metallic atoms for six carbon ones). Its critical temperature of 11.15 K is very close to that of CaC6 GIC (11.5 K). Both CaC6 and Li3Ca2C6 GICs possess currently the highest transition temperatures among all the GICs.Comment: 5 pages, 3 figure

SPHERE IRDIS and IFS astrometric strategy and calibration

We present the current results of the astrometric characterization of the VLT planet finder SPHERE over 2 years of on-sky operations. We first describe the criteria for the selection of the astrometric fields used for calibrating the science data: binaries, multiple systems, and stellar clusters. The analysis includes measurements of the pixel scale and the position angle with respect to the North for both near-infrared subsystems, the camera IRDIS and the integral field spectrometer IFS, as well as the distortion for the IRDIS camera. The IRDIS distortion is shown to be dominated by an anamorphism of 0.60+/-0.02% between the horizontal and vertical directions of the detector, i.e. 6 mas at 1". The anamorphism is produced by the cylindrical mirrors in the common path structure hence common to all three SPHERE science subsystems (IRDIS, IFS, and ZIMPOL), except for the relative orientation of their field of view. The current estimates of the pixel scale and North angle for IRDIS are 12.255+/-0.009 milliarcseconds/pixel for H2 coronagraphic images and -1.75+/-0.08 deg. Analyses of the IFS data indicate a pixel scale of 7.46+/-0.02 milliarcseconds/pixel and a North angle of -102.18+/-0.13 deg. We finally discuss plans for providing astrometric calibration to the SPHERE users outside the instrument consortium.Comment: 12 pages, 6 figures, 3 table

The Earth as an extrasolar transiting planet: Earth's atmospheric composition and thickness revealed by Lunar eclipse observations

An important goal within the quest for detecting an Earth-like extrasolar planet, will be to identify atmospheric gaseous bio-signatures. Observations of the light transmitted through the Earth's atmosphere, as for an extrasolar planet, will be the first step for future comparisons. We have completed observations of the Earth during a Lunar eclipse, a unique situation similar to that of a transiting planet. We aim at showing what species could be detected in its atmosphere at optical wavelengths, where a lot of photons are available in the masked stellar light. We present observations of the 2008 August 16 Moon eclipse performed with the SOPHIE spectrograph at the Observatoire de Haute-Provence. Locating the spectrograph fibers in the penumbra of the eclipse, the Moon irradiance is then a mix of direct, unabsorbed Sun light and solar light that has passed through the Earth's limb. This mixture essentially reproduces what is recorded during the transit of an extrasolar planet. We report here the clear detection of several Earth atmospheric compounds in the transmission spectra, such as ozone, molecular oxygen, and neutral sodium as well as molecular nitrogen and oxygen through the Rayleigh signature. Moreover, we present a method that allows us to derive the thickness of the atmosphere versus the wavelength for penumbra eclipse observations. We quantitatively evaluate the altitude at which the atmosphere becomes transparent for important species like molecular oxygen and ozone, two species thought to be tightly linked to the presence of life. The molecular detections presented here are an encouraging first attempt, necessary to better prepare for the future of extremely-large telescopes and transiting Earth-like planets. Instruments like SOPHIE will be mandatory when characterizing the atmospheres of transiting Earth-like planets from the ground and searching for bio-marker signatures.Comment: 15 pages, 14 figures, 2 tables. Accepted for publication in Astronomy and Astrophysic

Le numérique éducatif à l'école élémentaire en tension entre politiques nationales, politiques locales et logiques d'appropriation par les enseignants

International audienceCet article rend compte d'un travail de recherche réalisé par le laboratoire Techné de l'université de Poitiers portant sur le numérique éducatif à l'école élémentaire en France métropolitaine. Il découle d'une étude menée entre 2018 et 2019 et dont les principaux résultats ont été transmis à la Cour des comptes dans le cadre d'une contribution à ses travaux sur le sujet. Après une présentation des principaux résultats de l'étude centrale dans la première partie de l'article, les deux parties suivantes proposent d'aborder deux prolongements spécifiques identifiés : les liens entre équipements numériques disponibles et usages des enseignants et la confrontation entre politiques publiques et discours de terrain

Case report: Immune response characterization of a pseudoprogression in a PD-L1-negative, TMB-low, KEAP1/STK11 co-mutated metastatic NSCLC

A patient with a PD-L1-negative, TMB-low, KEAP1/STK11 co-mutated metastatic non-small cell lung cancer (NSCLC) experienced a multisite radiological progression at 3 months after initiation of chemoimmunotherapy as first-line treatment for metastatic disease. After the radiological progression, while she was not undergoing treatment, the patient had spontaneous lesions shrinkage and further achieved a prolonged complete response. Genomic and transcriptomic data collected at baseline and at the time of pseudoprogression allowed us to biologically characterize this rare response pattern. We observed the presence of a tumor-specific T-cell response against tumor-specific neoantigens (TNAs). Endogenous retroviruses (ERVs) expression following chemoimmunotherapy was also observed, concurrent with biological features of an anti-viral-like innate immune response with type I IFN signaling and production of CXCR3-associated chemokines. This is the first biological characterization of a NSCLC pseudoprogression under chemoimmunotherapy followed by a prolonged complete response in a PD-L1-negative, TMB-low, KEAP1/STK11 co-mutated NSCLC. These clinical and biological data underline that even patients with multiple factors of resistance to immune checkpoint inhibitors could trigger a tumor-specific immune response to tumor neoantigen, leading to complete eradication of the tumor and probably a vaccinal immune response