2,605 research outputs found
Analyse socio-spatiale de la vulnérabilité des migrants âgés
Poster présenté dans le cadre du 5ème colloque international du REIACTIS en 2016. Le poster présente les résultats d\u27une démarche de recension des écrits portant sur le thème du vieillissement des personnes âgées immigrées en France
Alien Registration- Martineau, Arnold A. (Van Buren, Aroostook County)
https://digitalmaine.com/alien_docs/32270/thumbnail.jp
Exact approximation of Rao-Blackwellised particle filters
Particle methods are a category of Monte Carlo algorithms that have become popular for performing inference in non-linear non-Gaussian state-space models. The class of 'Rao-Blackwellised' particle filters exploits the analytic marginalisation that is possible for some state-
space models to reduce the variance of the Monte Carlo estimates. Despite being applicable to only a restricted class of state-space models, such as conditionally linear Gaussian models, these algorithms have found numerous applications. In scenarios where no such analytical integration is possible, it has recently been proposed in Chen et al. [2011] to use 'local' particle filters to
carry out this integration numerically. We propose here an alternative approach also relying on \local" particle filters which is more broadly applicable and has attractive theoretical properties. Proof-of-concept simulation results are presented
Notice méthodologique pour réaliser un état de l’art en sciences humaines et sociales
Amorcer une démarche de recherche en sciences sociales représente un temps de découverte et de rencontre entre un objet de recherche et un chercheur. L’état de l’art en tant qu’étape préliminaire doit permettre au chercheur de dresser un panorama des savoirs sur son thème de recherche. Cet article a pour finalité de présenter comment le chercheur peut procéder scientifiquement à la réalisation de cette étape qui est consubstantielle à la structuration du projet de recherche et son positionnement dans le champ scientifique. L’évolution des technologies offre actuellement des outils numériques permettant d’assister le chercheur dans sa recension des écrits et de systématiser l’analyse des données bibliographiques. Cet article présentera les logiciels utilisés (Mendeley et Nvivo) et le procédé d’analyse qualitative mis en œuvre. Les intérêts et les limites de l’utilisation de ces logiciels seront développés au même titre que les enjeux rencontrés dans la production scientifique d’un état de l’art
New results from H.E.S.S. observations of galaxy clusters
Clusters of galaxies are believed to contain a significant population of
cosmic rays. From the radio and probably hard X-ray bands it is known that
clusters are the spatially most extended emitters of non-thermal radiation in
the Universe. Due to their content of cosmic rays, galaxy clusters are also
potential sources of VHE (>100 GeV) gamma rays. Recently, the massive, nearby
cluster Abell 85 has been observed with the H.E.S.S. experiment in VHE gamma
rays with a very deep exposure as part of an ongoing campaign. No significant
gamma-ray signal has been found at the position of the cluster. The
non-detection of this object with H.E.S.S. constrains the total energy of
cosmic rays in this system. For a hard spectral index of the cosmic rays of
-2.1 and if the cosmic-ray energy density follows the large scale gas density
profile, the limit on the fraction of energy in these non-thermal particles
with respect to the total thermal energy of the intra-cluster medium is 8% for
this particular cluster. This value is at the lower bounds of model
predictions.Comment: 4 pages, one figure, invited talk at the 2nd Heidelberg workshop:
"High-Energy Gamma-rays and Neutrinos from Extra-Galactic Sources", January
13 - 16, 2009, to be published in Int. J. Mod. Phys.
Magnetic states of linear defects in graphene monolayers: effects of strain and interaction
The combined effects of defect-defect interaction and of uniaxial or biaxial
strains of up to 10\% on the development of magnetic states on the
defect-core-localized quasi-one-dimensional electronic states generated by the
so-called 558 linear extended defect in graphene monolayers are investigated by
means of {\it ab initio} calculations. Results are analyzed on the basis of the
heuristics of the Stoner criterion. We find that conditions for the emergence
of magnetic states on the 558 defect can be tuned by uniaxial tensile parallel
strains (along the defect direction) at both limits of isolated and interacting
558 defects. Parallel strains are shown to lead to two cooperative effects that
favor the emergence of itinerant magnetism: enhancement of the DOS of the
resonant defect states in the region of the Fermi level and tuning of the Fermi
level to the maximum of the related DOS peak. A perpendicular strain is
likewise shown to enhance the DOS of the defect states, but it also effects a
detunig of the Fermi level that shifts away from the maximum of the DOS of the
defect states, which inhibts the emergence of magnetic states. As a result,
under biaxial strains the stabilization of a magnetic state depends on the
relative magnitudes of the two components of strain.Comment: 9 pages 8 figure
"Test me and treat me" - attitudes to vitamin D deficiency and supplementation: a qualitative study
© 2015 BMJ Open, "Test me and treat me"-attitudes to vitamin D deficiency and supplementation: a qualitative study. This manuscript version is made available under the Creative Commons Attribution Licens
H.E.S.S. observations of galaxy clusters
Clusters of galaxies, the largest gravitationally bound objects in the
universe, are expected to contain a significant population of hadronic and
leptonic cosmic rays. Potential sources for these particles are merger and
accretion shocks, starburst driven galactic winds and radio galaxies.
Furthermore, since galaxy clusters confine cosmic ray protons up to energies of
at least 1 PeV for a time longer than the Hubble time they act as storehouses
and accumulate all the hadronic particles which are accelerated within them.
Consequently clusters of galaxies are potential sources of VHE (> 100 GeV)
gamma rays. Motivated by these considerations, promising galaxy clusters are
observed with the H.E.S.S. experiment as part of an ongoing campaign. Here,
upper limits for the VHE gamma ray emission for the Abell 496 and Coma cluster
systems are reported.Comment: Contribution to the 30th ICRC, Merida Mexico, July 200
Vitamin D for the management of asthma (Protocol)
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To evaluate the efficacy of administration of vitamin D and its hydroxylated metabolites in reducing asthma exacerbations and improving asthma symptom control
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