236 research outputs found
Bayesian blind component separation for Cosmic Microwave Background observations
We present a technique for the blind separation of components in CMB data.
The method uses a spectral EM algorithm which recovers simultaneously component
templates, their emission law as a function of wavelength, and noise levels. We
test the method on Planck HFI simulated observations featuring 3 astrophysical
components.Comment: 15 pages, 5 figures, to appear in the Proceedings of the MAXENT 2001
international worksho
Delays in Biological Regulatory Networks
International audienceIn this article, we propose a refinement of the modeling of genetic regulatory networks based on the approach of René Thomas. The notion of delays of activation/inhibition are added in order to specify which variable is faster affected by a change of its regulators. The formalism of linear hybrid automata is well suited to allow such refinement. We then use HyTech for two purposes: (1) to find automatically all paths from a specified initial state to another one and (2) to synthesize co nstraints on the delay parameters in order to follow any specific path
Chondrocalcinose articulaire révélatrice d’une hypercalcémie hypocalciurique familiale: à propos d’une observation
L'hypercalcémie hypocalciurique familiale (HHF) est une maladie bénigne à transmission autosomique dominante, caractérisée par une hypercalcémie persistante béhigne, une hypocalciurie, et des concentrations de parathormone (PTH) normales ou modérément élevées, sans complication secondaire à l'hypercalcémie. Nous rapportons l'observation d'un patient ayant présenté une chondrocalcinose articulaire révélatrice d'une HHF. A travers cette observation nous essayons de décrire les aspects épidémiologiques, les caractéristiques cliniques, et paracliniques de cette association
Efficiency improvement of LDO ouput based linear regulator with supercapacitor energy recovery - a versatile new technique with an example of a 5v to 1.5 v version
Supercapacitors are used in various industrial applications and the supercapacitors technology is gradually progressing into a mature state. Common applications of supercapacitors are in electric vehicles, hybrid electric vehicles, uninterruptible power supply (UPS) and in portable devices such as cellular phones and laptops. The capacitance values range from fractional Farads to few thousand Farads and their continuos DC voltage ratings are from 2V to 6V.
At University of Waikato, a team works on using supercapacitors for improving the efficiency of linear voltage regulators. In particular, this patented technique aims at combining off the shelfs LDO ICs and a supercapacitor array for improving end to end efficiency of linear regulator.
My work is aimed at developing the theoretical background and designing prototype circuitry for a voltage regulator for the case of unregulated input supply is more than 3 times of the minimum input voltage requirement of the LDO which is applicable for a 5V to 1.5V regulator. Experimental results are indicated with future suggestions for improvement
Sélection de variables stabilométriques pour l'analyse et la détection de la dégradation de l'équilibre postural
L'étude de la posture statique présente un grand intérêt pour l'analyse du déficit du contrôle de l'équilibre. Une méthode d'analyse de l'équilibre consiste à utiliser une plate-forme de forces qui permet d'extraire le déplacement du centre de pression (CdP). Les paramètres extraits du CdP s'avèrent comme des variables clés pour surveiller la dégradation de l'équilibre. Cependant, la non pertinence et\ou la redondance de certains d'entre eux rendent difficile une détection efficace d'une dégradation. L'objectif de cet article est l'implémentation d'une méthode de détection à noyau (SVDD) et d'une procédure de sélection des paramètres pertinents capables de détecter une dégradation de l'équilibre. Le critère de sélection choisi est la maximisation de la surface sous la courbe COR
Vortex phase transition and superconducting properties of organic quasi-two-dimensional k-(BEDT-TTF) 2 Cu[N(CN) 2 ]Br
International audienceWe report investigations of the low temperature dc susceptibility and the magnetization on the layered organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br near 80K and the effect of disorder on the superconducting transition temperature Tc. The shielding effect (S) and the critical current density Jc were studied (with H parallel to the c axis of the crystal). Jc can be estimated by analysis of magnetic hysteresis measurement using the Bean model. For each temperature value, we observed two regimes in the critical current density Jc(H). This result implies that there exists a first-order phase transition in the vortex system in this organic superconductor. Our results show that the magnetic properties of these compounds depend strongly on the cooling rate. The structural transformation which occurs at the vicinity of 80K very strongly influences the physics of vortex lattice and the associated magnetic behavior
Virulence properties and random amplification of polymorphic DNA (RAPD) fingerprinting of Candida albicans isolates obtained from Monastir dental hospital, Tunisia
Genotypic and phenotypic characterization as well as studies on the virulence factors of Candida albicans isolates obtained from oral cavity of patients was carried out using random amplified polymorphic DNA (RAPD) fingerprinting and epithelial cells adherence assay, respectively. RAPD patterns revealed the presence of 13 C. albicans genotypes separated into two clusters at 75% ofsimilarity when they were combined. Results also showed the presence of haemolytic protease activity as virulence factors with 88% of the C. albicans strains been able to adhere to Caco-2 cells and only 64% to Hep-2. RAPD-polymerase chain reaction (PCR) is a molecular tool used to differentiate the isolates into various genotypes based on their virulence properties.Key words: Candida albicans, stomatitis, random amplified polymorphic DNA, Hep-2, Caco-2 cells
Separation of instrumental and astrophysical foregrounds for mapping CMB anisotropies
We address the extended problem of component separation for CMB applications
when a mixture of both astrophysical and instrumental components are present in
the observations, and show how standard methods can be adapted to handle this
more complex inversion problem.Comment: 12 pages, 5 figures, submitted to MNRA
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