Search results for "donnée"
showing 10 items of 170 documents
Conservation et réquisition des données relatives aux communications électroniques : un débat serein est-il enfin possible ?
2022
Optimisation non-lisse pour l'estimation de composants immunitaires cellulaires dans un environnement tumoral
2021
In this PhD proposal we will investigate new regularization methods of inverse problems that provide an absolute quantification of immune cell subpopulations. The mathematical aspect of this PhD proposal is two-fold. The first goal is to enhance the underlying linear model through a more refined construction of the expression matrix. The second goal is, given this linear model, to derive the best possible estimator. These two issues can be treated in a decoupled way, which is the standard for existing methods such as Cibersort, or as a coupled optimization problem (which is known as blind deconvolution in signal processing).
Plasmon de surface de particules métalliques toroïdales
2006
This thesis deals with the optical properties of small metal torii. A method of resolution of the equation of Laplace in toroidal coordinates is introduced and the radiative properties of the metal toric nanoparticules are studied within the electrostatic framework. The study on the eigenmodes spatial distribution suggests that metal nanotorus can carry a non-zero magnetic dipole moment at optical frequencies. Analytical expressions for the extinction and scattering cross sections of the torus are also found and compared with numerical simulations and experimental results obtained with collaborations. The sensitivity of the plasmon frequency to the refraction index of the external medium an…
EVASPA (EVapotranspiration Assessment from SPAce) tool: an overview
2013
International audience; Evapotranspiration (ET) is a fundamental variable of the hydrological cycle and its estimation is required for irrigation management, water resources planning and environmental studies. Remote sensing provides spatially distributed cost-effective information for ET maps production at regional scale. We have developed EVASPA too for mapping ET from remote sensing data at spatial and temporal scales relevant to hydrological or agronomica studies. EVASPA includes several algorithms for estimating evapotranspiration and various equations for estimating the required input information (net radiation, ground heat flux, evaporative fraction…), which provides a way to assess …
Towards better privacy preservation by detecting personal events in photos shared within online social networks
2015
Today, social networking has considerably changed why people are taking pictures all the time everywhere they go. More than 500 million photos are uploaded and shared every day, along with more than 200 hours of videos every minute. More particularly, with the ubiquity of smartphones, social network users are now taking photos of events in their lives, travels, experiences, etc. and instantly uploading them online. Such public data sharing puts at risk the users’ privacy and expose them to a surveillance that is growing at a very rapid rate. Furthermore, new techniques are used today to extract publicly shared data and combine it with other data in ways never before thought possible. Howeve…
Impact des allocations en ressources sur l'efficacité des écoles primaires en Côte d'Ivoire
2011
The quality of primary education in Côte d'Ivoire has deteriorated sharply over the past three decades. This situation is the result of an approximate management of the education system, which is characterized by a lack of educational support, a misallocation of resources, a congestion of classrooms (42 students for a teacher in primary school) and a lack of skilled and well trained teachers. In addition, the military-political conflict in September 2002 did not allow to improve this situation; on the contrary, it has further deteriorated the situation. Thus, the aim of this thesis is first to analyze the influence of resource endowments on the effectiveness of primary schools in Cote d'Ivo…
Predictors of smoking cessation among smokers with cardiovascular diseases and risks factors in the French smoking cessation services national databa…
2022
Background: Smoking represents a major modifiable risk factor for cardiovascular diseases (CVD), particularly in women. The smoking prevalence in France is among the highest in Europe, and the identification of factors associated with smoking cessation in high-risk CV populations remains poorly studied, specifically when potential sex-disparities might exist. The objective of this work was firstly to describe the current state of knowledge on the association between tobacco consumption and CVD risk in women, through a literature review. Then, using the French national smoking cessation consultations database - CDTnet, to describe the socio-demographic profile, medical profile and smoking be…
How Big Data Informs Us About the Population Health Status : endophthalmitis after ophthalmologic procedures
2022
The use of Big Data, in the form of almost exhaustive French medico-administrative databases, has made it possible to address several issues without which this would not have been possible. First, to define the incidence of endophthalmitis after ophthalmologic procedures without bias on specific recruitment modalities of respondents (tertiary centers, questionnaires ...). Thus, local observations of a change in prevalence trends of causative procedures were confirmed at the national level. The reliable description of the incidence of endophthalmitis will then make it possible to identify critical situations of recrudescence of cases. The knowledge of the delay of occurrence after the proced…
Multispectral imaging and its use for face recognition : sensory data enhancement
2015
In this thesis, we focus on multispectral image for face recognition. With such application,the quality of the image is an important factor that affects the accuracy of therecognition. However, the sensory data are in general corrupted by noise. Thus, wepropose several denoising algorithms that are able to ensure a good tradeoff betweennoise removal and details preservation. Furthermore, characterizing regions and detailsof the face can improve recognition. We focus also in this thesis on multispectral imagesegmentation particularly clustering techniques and cluster analysis. The effectiveness ofthe proposed algorithms is illustrated by comparing them with state-of-the-art methodsusing both…
L'évaluation avec des données administratives comme outil de compréhension des facteurs de réorientation : le cas des étudiants de santé en échec dan…
2019
International audience; Cette communication présente une facette des possibilités de connaissance des parcours étudiants à partir de sources d'informations administratives d'une université. Dans le cadre de l'évaluation d'un dispositif de réorientation des étudiants en échec en 1ère année des études médicales réalisée pour cinq promotions de " réorientés/exclus " (964 étudiants sur les 7 169 inscrits), cette communication souligne comment caractériser des parcours de réorientation rapide. Les premiers travaux réalisés à partir du système de gestion des inscriptions et des examens montrent les spécificités des étudiants choisissant une réorientation immédiate en délaissant le dispositif inst…