414 research outputs found
A pairwise likelihood approach for the empirical estimation of the underlyingvariograms in the plurigaussian models
The plurigaussian model is particularly suited to describe categorical
regionalized variables. Starting from a simple principle, the thresh-olding of
one or several Gaussian random fields (GRFs) to obtain categories, the
plurigaussian model is well adapted for a wide range ofsituations. By acting on
the form of the thresholding rule and/or the threshold values (which can vary
along space) and the variograms ofthe underlying GRFs, one can generate many
spatial configurations for the categorical variables. One difficulty is to
choose variogrammodel for the underlying GRFs. Indeed, these latter are hidden
by the truncation and we only observe the simple and cross-variogramsof the
category indicators. In this paper, we propose a semiparametric method based on
the pairwise likelihood to estimate the empiricalvariogram of the GRFs. It
provides an exploratory tool in order to choose a suitable model for each GRF
and later to estimate its param-eters. We illustrate the efficiency of the
method with a Monte-Carlo simulation study .The method presented in this paper
is implemented in the R packageRGeostats.Comment: To be submitted to Spatial Statistic
Operational monitoring of radioelectric exposure in an urban environment
International audiencePolemics about base stations of cellular telephones have become a recurrent source of conflict among telecommunication companies, city authorities and citizens. Following early work performed within the framework of a doctoral thesis, the french research projet ANR Samper (2008-2011) has set up, for the first time, a network of monitoring stations in an urban environment, whose measurements are processed continuously by geostatistical methods, in order to inform daily the inhabitants on the hourly variations of radioelectric exposure in their surroundings. More precisely, the system uses a kriging of the exposure measurements including as external drift the output of a physical model of the propagation of the radioelectric signal emitted at different frequencies by the base stations. We present the implementation of the ANR Samper pre-operational monitoring system set up during several months in a section of the city of Grenoble
Comment dire, comment traduire ? BrĂšves notes de lecture sur le vocabulaire des politiques sociales. Portonnier, J.-C. 1998. Glossaire bilingue de la protection sociale , volume 1, Les Termes français/French Terms. Paris, MIRE, Rencontres et recherches. Ăvauger, J.-P., et P. Spicker. 1998. Social Protection : A Bilingual Glossary, volume 2, English Terms/Les Termes anglais. Paris, MIRE, Rencontres et recherches. Edwards, J., et J.-P. RĂ©vauger, Ă©d. 1998. Discourse on Inequality in France and Britain. AIdershot, Ashgate. Gordon, D., et P. Spicker, dir. 1999. The International Glossary on Poverty. Londres, Zed Books.
Joint modelling of repeated measurements and event time: Application to performance traits and survival of lambs bred in sub-humid tropics
We considered the analysis of a study for Dorper, Red Maasai and crossbred lambs born over a period of 6 years at the Diani Estate, Kenya. The study was designed to compare survival and performance traits of genotypes with differing susceptibilities to helminthiasis. The available data include information on time to death and repeated measurements of body weight, packed cell volume (PCV) and faecal egg count (FEC) of the animals. In the paper, we consider joint modelling of the survival time and the repeated measurements. Such an approach allows to account for the possible association between the survival and repeated measurement processes. The advantages and limitations of the joint modelling are discussed and illustrated using the Diani Estate study data
Joint modelling of repeated measurements and event time: Application to performance traits and survival of lambs bred in sub-humid tropics
Study of the relationship between the observed and simulated overflow drainage system in the Greater Lyon
Retour dâexpĂ©rience sur les apports du gĂ©ographe dans lâobservation des effets du changement climatique
Lâadaptation au changement climatique constitue un dĂ©fi sociĂ©tal dont le gĂ©ographe doit sâemparer. Sa capacitĂ© dâapprĂ©hender le territoire et ses acteurs, ainsi que sa vision holistique, en font un interlocuteur privilĂ©giĂ© des politiques publiques dâamĂ©nagement. A partir dâun retour dâexpĂ©rience concernant la mĂ©tropole lyonnaise, cette publication dĂ©montre le rĂŽle jouĂ© par le gĂ©ographe dans la structuration et lâinnovation, selon une dĂ©marche intĂ©grĂ©e et au sein dâune structure plurielle dâobservation scientifique.Adaptation to climate change can be currently considered as a societal challenge that geographers must tackle. Their capacity to understand the territory and its actors, and their holistic vision, make them privileged partners of the public urban planners. This paper, concerning an ongoing project about the Greater Lyon, highlights the role of geographers in the structuration and innovation, according to an integrated process and within a plural scientific observation structure
SynthÚse d'amides gras N-substitués par catalyse enzymatique
L'invention concerne un procédé de synthÚse d'amides gras N-substitués par réaction d'un composé organique présentant une fonction acide terminale et un composé organique présentant une fonction amine terminale caractérisé en ce que ladite réaction est effectuée en présence d'une enzyme de la classe des acyltransférase
Effect of a musical intervention on tolerance and efficacy of non-invasive ventilation in the ICU: study protocol for a randomized controlled trial (MUSique pour lâInsuffisance Respiratoire Aigue - Mus-IRA)
NIV protocol. (DOCX 103 kb
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