Search results for "statistiques"
showing 10 items of 48 documents
From optimization to algorithmic differentiation: a graph detour
2021
This manuscript highlights the work of the author since he was nominated as "Chargé de Recherche" (research scientist) at Centre national de la recherche scientifique (CNRS) in 2015. In particular, the author shows a thematic and chronological evolution of his research interests:- The first part, following his post-doctoral work, is concerned with the development of new algorithms for non-smooth optimization.- The second part is the heart of his research in 2020. It is focused on the analysis of machine learning methods for graph (signal) processing.- Finally, the third and last part, oriented towards the future, is concerned with (automatic or not) differentiation of algorithms for learnin…
Le congé individuel de formation : un droit national, des déclinaisons régionales
2008
Le congé individuel de formation (CIF) est un droit des salariés à suivre une formation de leur choix, tout au long de leur vie professionnelle, en bénéficiant d’une prise en charge totale ou partielle de leur rémunération et des coûts de formation. Dans le secteur privé, 34 000 salariés sous contrat à durée indéterminée ont bénéficié en 2005 du financement d’un CIF. Les Fongecif gèrent, dans chaque région, les fonds alloués au CIF par les entreprises et instruisent les dossiers des requérants. Ils disposent d’une large autonomie d’organisation et de gestion.Au quotidien, les Fongecif interprètent localement les règles générales encadrant l’accès au CIF, notamment afin de gérer la contraint…
Bayesian spatio-temporal discard model in a demersal trawl fishery
2014
Spatial management of discards has recently been proposed as a useful tool for the protection of juveniles, by reducing discard rates and can be used as a buffer against management errors and recruitment failure. In this study Bayesian hierarchical spatial models have been used to analyze about 440 trawl fishing operations of two different metiers, sampled between 2009 and 2012, in order to improve our understanding of factors that influence the quantity of discards and to identify their spatio-temporal distribution in the study area. Our analysis showed that the relative importance of each variable was different for each metier, with a few similarities. In particular, the random vessel eff…
Timing and patterns of the ENSO signal in Africa over the last 30 years: insights from normalized difference vegetation index data.
2014
Abstract A more complete picture of the timing and patterns of the ENSO signal during the seasonal cycle for the whole of Africa over the three last decades is provided using the normalized difference vegetation index (NDVI). Indeed, NDVI has a higher spatial resolution and is more frequently updated than in situ climate databases, and highlights the impact of ENSO on vegetation dynamics as a combined result of ENSO on rainfall, solar radiation, and temperature. The month-by-month NDVI–Niño-3.4 correlation patterns evolve as follows. From July to September, negative correlations are observed over the Sahel, the Gulf of Guinea coast, and regions from the northern Democratic Republic of Congo…
"Faire du chiffre" pour exister. Les gendarmes et les policiers au principe des statistiques judiciaires (1875-1914)
2007
International audience; Gendarmes et policiers sont au XIXe siècle, déjà, les principaux pourvoyeurs de la justice pénale. À ce titre, ils jouent un rôle fondamental dans la construction de la statistique judiciaire, compilée annuellement dans le Compte général de l'administration de la justice criminelle. Sous la Troisième République, la crise sécuritaire, expose les forces de l'ordre à de violentes critiques. Ces attaques s'appuient sur des statistiques criminelles en hausse qui accréditeraient l'impéritie des gendarmes et des policiers. Stigmatisés au nom de chiffres, gendarmes et policiers cherchent alors à retrouver une légitimité institutionnelle et une utilité sociale en présentant d…
The participant interview: a method to understand the individual's experience in the car
2019
L’individu dans son automobile, durant ses déplacements quotidiens, habite d’une façon ou d’une autre l’espace circonscrit dans lequel il se trouve alors. De ce point de vue, il apparaît nécessaire de développer une ethno-sociologie des manières d’habiter son automobile. Pour atteindre cette ambition heuristique, nous préciserons ici les termes de cette méthode que nous nommons « entretien participant ». Hybridant les méthodes de l’entretien et de l’observation participante, l’entretien du rapport de l’individu contemporain à son automobile alternant sans cesse entre réflexivité et routines, entre repli sur soi et disponibilité au monde et à soi.
Weeds sampling for map reconstruction: a Markov random field approach
2012
In the past 15 years, there has been a growing interest for the study of the spatial repartition of weeds in crops, mainly because this is a prerequisite to herbicides use reduction. There has been a large variety of statistical methods developped for this problem ([5], [7], [10]). However, one common point of all of these methods is that they are based on in situ collection of data about weeds spatial repartition. A crucial problem is then to choose where, in the eld, data should be collected. Since exhaustive sampling of a eld is too costly, a lot of attention has been paid to the development of spatial sampling methods ([12], [4], [6] [9]). Classical spatial stochastic model of weeds cou…
It’s a matter of confidence. Institutions, government stability and economic outcomes
2021
In this paper we analyse the effect of constitutional structures over policy outcomes. In particular, we exploit the heterogeneity in parliamentary systems deriving from the presence and the use of the confidence vote to investigate whether stable and unstable parliamentary systems behave differently in terms of the policies they implement. This finer partition of parliamentary systems allows us to identify effects that are more robust than the ones previously discussed in the literature. We show that the difference between presidential and parliamentary systems documented in previous works is driven by a difference between presidential and stable parliamentary systems. We suggest that poss…
Modélisation de scènes agronomiques pour tester et comparer les performances d'algorithmes de discrimination d'adventices
2007
International audience; Dans le cadre de l’agriculture de précision, l’imagerie s’avère être de plus en plus utilisée commeoutil d’aide à la décision pour une gestion spécifique des intrants dans des parcelles cultivées.Dans ce contexte, nous présentons une modélisation de scènes agronomiques afin d’évaluer etde comparer la précision et la robustesse d’algorithmes de discrimination culture/adventices. Lamodélisation de ces images se décompose en deux parties : la première consiste en la modéli-sation d’une parcelle cultivée en simulant la distribution spatiale des plantes (culture et mauvai-ses herbes), la seconde a pour but de projeter le résultat obtenu à travers un capteur optiquepour si…
Diagnosis and predictability of intraseasonal characteristics of wet and dry spells over equatorial east Africa
2010
Most of Eastern Africa has arid and semi-arid climate with high space-time variability in rainfall. The droughts are very common in this region, and often persist for several years, preceded or followed by extreme floods. Most of the livelihoods and socio-economic activities however remain rain-dependent leading to severe negative impacts during the periods of occurrence of climate extremes. It has been noted that one extreme event was capable of reversing national economic growth made over a period of several years. Thus no sustainable development can be attained in eastern Africa without effective mainstreaming of climate information in the development policies, plans and programmes. Many…