A Shannon's theory of knowledge

Our so-called "Information Society", is gradually changing into a "Knowledge Society". The Shannons Theory provided a formal and mathematical framework for information. It was very fruitful for avoiding ambiguity on the concept of information. This paper proposes a transposition of this theory for knowledge. From the three axes of a formal model designed for knowledge engineering (information, sense and context), three quantitative measures are proposed to get a measure of the quantity of knowledge of a system. This notion permits to consider applications as the cognitive measure of a web site, a knowledge community (community of practice…).Knowledge, Knowledge management, Shannon's theory

Numerical modeling of mechanical contact in deformable NEMS

International audienceThis work focuses on the modeling of mechanical contact applied to Nano-Electro-Mechanical-Systems (NEMS). A magneto-elastic formulation associated to the definition of unilateral contact in static case is presented. This model is discretised by finite element method and a numerical study of a magnetic nano switch is performed

Rapport de jury - Concours (session 2008) de recrutement des conservateurs des bibliothèques[Fonction publique d’Etat]

Rapport de jury du concours de conservateur d\u27Etat externe et interne : * lacunes de l\u27ancien concours et points forts de la réforme * sujets, commentaires et statistiques pour les épreuves de la session 200

On the derivation of radial velocities of SB2 components: a "CCF vs TODCOR" comparison

The radial velocity (RV) of a single star is easily obtained from cross-correlation of the spectrum with a template, but the treatment of double-lined spectroscopic binaries (SB2s) is more difficult. Two different approaches were applied to a set of SB2s: the fit of the cross-correlation function with two normal distributions, and the cross-correlation with two templates, derived with the TODCOR code. It appears that the minimum masses obtained through the two methods are sometimes rather different, although their estimated uncertainties are roughly equal. Moreover, both methods induce a shift in the zero point of the secondary RVs, but it is less pronounced for TODCOR. All-in-all the comparison between the two methods is in favour of TODCOR.Comment: 5 pages, 4 figures, SF2A Conference 201

Finite Element Modeling of deformable NEMS taking into accountmechanical contact

International audienceThis work focuses on the modeling of mechanical contact applied to Nano-Electro-Mechanical-Systems (NEMS). A magneto-elastic formulation associated to the definition of unilateral contact in static case is presented. This model is discretised by finite element method and a numerical study of a magnetic nano switch is performed. FEM results are compared to those of a semi-analytical model developed for optimization processes

Masses of the components of SB2 binaries observed with Gaia. I. Selection of the sample and mass ratios of 20 new SB2s discovered with Sophie

In anticipation of the Gaia astrometric mission, a large sample of spectroscopic binaries is being observed since 2010 with the Sophie spectrograph at the Haute--Provence Observatory. Our aim is to derive the orbital elements of double-lined spectroscopic binaries (SB2s) with an accuracy sufficient to finally obtain the masses of the components with relative errors as small as 1% when the astrometric measurements of Gaia are taken into account. Simultaneously, the luminosities of the components in the Gaia photometric band G will also be obtained. Our observation program started with 200 SBs, including 152 systems that were only known as single-lined. Thanks to the high efficiency of the Sophie spectrograph, an additional component was found for 25 SBs. After rejection of 5 multiple systems, 20 new SB2s were retained, including 8 binaries with evolved primary, and their mass ratios were derived. Our final sample contains 68 SB2s, including 2 late-type giants and 10 other evolved stars.Comment: 8 pages, 3 figures, accepted for publication in MNRA