On simulations about the precision of non uniform hybrid filter bank analog/digital converters

©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.International audienceIn this paper we present a theoretical study of the errors due to imperfect reconstruction and to quantization in hybrid filter bank (HFB) analog/digital (A/D) converters, that are non uniform i.e., with K channels and an arbitrary ratio M of the M-fold expanders (M ≤ K). We propose then a new method of simulation for such HFB A/D converters that avoids any numerical computation of differential equation solutions. The results of simulation are compared with theoretical ones. Moreover, in HFB A/D converter studies, the effect of quantization noise is generally indicated by its average power at the output of the HFB, when it is M-cyclostationary. This paper shows on an example that the variance of the global error at the HFB output can vary a lot in a period of M samples

Dosage du potassium dans divers aliments en vue de la mesure de la Radioactivité de ces aliments

Morre Jean, Barret Jean. Dosage du potassium dans divers aliments en vue de la Radioactivité de ces aliments. In: Bulletin de l'Académie Vétérinaire de France tome 114 n°8, 1961. pp. 321-325

Sainte-Luce – Gros-Raisin

Ce site néolithique se trouve à l’ouest du bourg de Sainte-Luce, sur un promontoire rocheux entre l’Anse Corps de Garde et la Pointe Philippeaux. Surélevé par rapport à la mer, il est protégé des vagues et de l’humidité de la mangrove environnante, tout en offrant un accès aisé aux zones riches en ressources alimentaires. Au nord, le substrat rocheux était bordé par la mangrove, aujourd’hui comblée, du lieu-dit Pont Café. Avant le remblaiement de cette mangrove, voici quelques années, le plat..

Le Diamant – Habitation O’Mullane

Les ruines de cette ancienne habitation sucrière se trouvant actuellement sur une propriété privée, la municipalité avait alerté les archéologues au sujet des intentions de l’actuel propriétaire de lotir la parcelle. Dans un premier temps, le travail a essentiellement consisté en un repérage des vestiges de constructions, enfouis dans une épaisse végétation arborée, en particulier des ficus, qui pousse directement sur le sommet des murs. L’enlèvement de la végétation dans les endroits à sonde..

Le Diamant – Habitation Dizac

L’habitation sucrerie de Dizac (fig. 1) est située au sud de la ravine Dizac à flanc de morne à 3 km environ du bourg du Diamant, à côté de la route départementale D57 dite de Petite Anse. Fig. 1 – Plan de l’habitation Dizac N. Vidal, J.-B. Barret. À l’occasion d’un projet d’aménagement hôtelier près de l’emplacement de la sucrerie Dizac, un sauvetage urgent a été réalisé sur les installations industrielles qui, d’après les connaissances actuelles, dateraient du début du xviiie siècle. À cet..

Totally laparoscopic aortic repair: A new device for direct transperitoneal approach

On the basis of our experience with more than 71 cases of totally laparoscopic aortic surgery by the retrocolic approach, we have developed a new technique by a simple transperitoneal approach. The purpose of this report is to describe that technique and the novel laparoscopic bowel retractor used to ensure stable exposure of the aorta

Organisation et rôle de la profession agricole dans le développement des systèmes irrigués : quelques enseignements tirés du cas de l'Office du Niger au Mali

Cette communication traite du rôle des organisations paysannes dans le développement agricole au Mali et en particulier pour la zone de l'Office du Niger. Les politiques d'ajustement, puis maintenant de post-ajustement, donnent un rôle croissant aux organisations paysannes dans divers cadres de concertation où doivent se négocier les politiques sectorielles et se cogérer les filières agricoles. A travers le cas du Mali et plus particulièrement de la zone irriguée de l'Office du Niger (mais aussi de la filière coton), il est mis en en balance les nouveaux enjeux auxquels se trouvent confrontées les organisations de producteurs - extension du domaine aménagé, gestion du périmètre irrigué, amélioration de la productivité - et leurs capacités à les relever, capacités qui sont fortement liées aux diverses conditions de leur émergence. (Résumé d'auteur

The coherence of kHz quasi-periodic oscillations in the X-rays from accreting neutron stars

We study in a systematic way the quality factor of the lower and upper kHz QPOs in a sample of low luminosity neutron star X-ray binaries, showing both QPOs varying over a wide frequency range. The sample includes 4U 1636-536, 4U 1608-522, 4U 1735-44, 4U 1728-34, 4U 1820-303 and 4U 0614+09. We find that all sources except 4U 0614+091 show evidence of a drop in the quality factor of their lower kHz QPOs at high frequency. For 4U 0614+091 only the rising part of the quality factor versus frequency curve has been sampled so far. At the same time, in all sources but 4U 1728-34, the quality factor of the upper kilo-Hz QPO increases all the way to the highest detectable frequencies. We show that the high-frequency behaviours of both the lower and upper kHz QPO quality factors are consistent with what is expected if the drop is produced by the approach of an active oscillating region to the innermost stable circular orbit: the existence of which is a key feature of General Relativity in the strong field regime. Within this interpretation, our results imply gravitational masses around 2 solar masses for the neutron stars in those systems.Comment: Accepted for publication in MNRAS, 8 pages, 8 figures, figure 1 in colo

Evolution of AQL X-1 During the Rising Phase of its 1998 Outburst

We present results from 16 snapshots of Aql X-1 with RXTE during the rising phase of its recent outburst. The observations were carried out at a typical rate of once or twice per day. The source shows interesting spectral evolution during this period. Phenomenologically, it bears remarkable similarities to ``atoll'' sources. Shortly after the onset of the outburst, the source is seen to be in an ``island'' state, but with little X-ray variability. It then appears to have made a rapid spectral transition (on a time scale less than half a day) to another ``island'' state, where it evolves slightly and stays for 4 days. In this state, the observed X-ray flux becomes increasingly variable as the source brightens. Quasi-period oscillation (QPO) in the X-ray intensity is detected in the frequency range 670--870 Hz. The QPO frequency increases with the X-ray flux while its fractional rms decreases. The QPO becomes undetectable following a transition to a ``banana'' state, where the source continues its evolution by moving up and down the ``banana'' branch in the color-color diagram as the flux (presumably, the mass accretion rate) fluctuates around the peak of the outburst. Throughout the entire period, the power density spectrum is dominated by very-low frequency noises. Little power can be seen above ~1 Hz, which is different from typical ``atoll'' sources. In the ``banana'' state, the overall X-ray variability remains low (with fractional rms ~3--4%) but roughly constant. The observed X-ray spectrum is soft with few photons from above $\sim$25 keV, implying the thermal origin of the emission. The evolution of both spectral and temporal X-ray properties is discussed in the context of disk-instability models.Comment: 13 pages, including one table and five figures. To appear in ApJ Letters (July 20

Discrete Wavelet Transform and Optimal Spectral Transform Applied to Multicomponent Image Coding

ISBN 978-953-307-482-5 Chapitre 10International audienc