87 research outputs found

    Intérêt du suivi de fréquences pour la détection de sources harmoniques multiples

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    National audienceDans cet article, nous présentons une nouvelle approche pour la localisation de superposition de sources harmoniques. Notre méthode est basée sur le suivi des fréquence prédominantes du signal afin de former des segments sinusoïdaux. Les relations entre les fréquences de ces derniers sont ensuite étudiées afin de regrouper les segments sinusoïdaux appartenant à une même source. Les sources étant localisées sur le plan temps-fréquence, les zones où coexistent différentes sources sont finalement extraites. Notre approche à été testée à la fois sur des contenus de parole et de musique avec des résultats prometteurs

    Audio Indexing Including Frequency Tracking of Simultaneous Multiple Sources in Speech and Music

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    National audienceIn this paper, we present a complete system for audio indexing. This system is based state-of-the-art methods of Speech-Music-Noise segmentation and Monophonic/Polyphonic estimation. After those methods we propose an original system of superposed sources detection. This approach is based on the analysis of the evolution of the predominant frequencies. In order to validate the whole system we used different corpora : Radio broadcasts, studio music and degraded field records. The first results are encouraging and show the potential of our approach which is generic and can be used on both music and speech contents

    Chronic Social Stress Time-Dependently Affects Neuropathic Pain-Related Cold Allodynia and Leads to Altered Expression of Spinal Biochemical Mediators

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    Clinical data have shown that chronic exposure to stress may be accompanied by an enhancement of inflammation-related pain sensitivity. In this context, little is however known on the impact of stress on neuropathic pain. In the present study we addressed this issue by combining the chronic constriction injury (CCI) model with an ongoing social stress (OSS) paradigm. Cold plate and von Frey tests were performed in 48 rats divided into four groups: OSS exposed to OSS, CCI subjected to chronic nerve constriction, OSS+CCI with a combination of neuropathy and stress and CON, a control group lacking any manipulation. While we did not observe any stress-related differences in mechanical sensitivity throughout the observation period, CCI rats were more sensitive to cold stimulation than OSS+CCI in the initial phase of neuropathy. A switch was observed at a later stage, leading to a hypersensitivity of the OSS+CCI compared to the CCI rats. At this time point we investigated the spinal mRNA expression of neuron and glia related molecules potentially involved in neuropathic pain and stress. The combination of psychosocial stress and neuropathic pain seemed to enhance glial cell activation, pro-inflammatory cytokine and neurotrophic factor mRNA levels, rather than glutamatergic transmission. Our data show that long lasting social stress may lead to time-dependent alteration of neuropathy-related cold pain sensitivity while mechanicallyinduced pain remains unchanged

    HyMeX: A 10-Year Multidisciplinary Program on the Mediterranean Water Cycle

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    Drobinski, P. ... et. al.-- 20 pages, 10 figures, 1 table, supplement material http://journals.ametsoc.org/doi/suppl/10.1175/BAMS-D-12-00244.1HyMeX strives to improve our understanding of the Mediterranean water cycle, its variability from the weather-scale events to the seasonal and interannual scales, and its characteristics over one decade (2010–20), with a special focus on hydrometeorological extremes and the associated social and economic vulnerability of the Mediterranean territoriesHyMeX was developed by an international group of scientists and is currently funded by a large number of agencies. It has been the beneficiary of financial contributions from CNRS; Météo-France; CNES; IRSTEA; INRA; ANR; Collectivité Territoriale de Corse; KIT; CNR; Université de Toulouse; Grenoble Universités; EUMETSAT; EUMETNET; AEMet; Université Blaise Pascal, Clermont Ferrand; Université de la Méditerranée (Aix-Marseille II); Université Montpellier 2; CETEMPS; Italian Civil Protection Department; Université Paris- Sud 11; IGN; EPFL; NASA; New Mexico Tech; IFSTTAR; Mercator Ocean; NOAA; ENEA; TU Delft; CEA; ONERA; IMEDEA; SOCIB; ETH; MeteoCat; Consorzio LAMMA; IRD; National Observatory of Athens; Ministerio de Ciencia e Innovación; CIMA; BRGM; Wageningen University and Research Center; Department of Geophysics, University of Zagreb; Institute of Oceanography and Fisheries, Split, Croatia; INGV; OGS; Maroc Météo; DHMZ; ARPA Piemonte; ARPA-SIMC Emilia-Romagna; ARPA Calabria; ARPA Friuli Venezia Giulia; ARPA Liguria; ISPRA; University of Connecticut; Università degli Studi dell'Aquila; Università di Bologna; Università degli Studi di Torino; Università degli Studi della Basilicata; Università La Sapienza di Roma; Università degli Studi di Padova; Università del Salento; Universitat de Barcelona; Universitat de les Illes Balears; Universidad de Castilla-La Mancha; Universidad Complutense de Madrid; MeteoSwiss; and DLR. It also received support from the European Community's Seventh Framework Programme (e.g., PERSEUS, CLIM-RUN)Peer reviewe

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

    Réduction de la consommation statique des circuits intégrés en technologie SOI 65 nm partiellement désertée

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    Partially depleted SOI technologies (PD-SOI), offer advantages in terms of speed and dynamic power consumption compared to bulk technologies. The main drawback of the PD-SOI technology is its static power consumption, which is higher than bulk one. It is due to the floating body of its transistors. This work presents a new static power consumption design technique based on power switches. A new factor of merit is introduced selecting the power switch with the best trade-off in terms of leakage current, speed and area. A new power switch brings, in comparison to a reference solution, a reduction of 20% of the ON mode equivalent resistance for the same OFF mode leakage current PD-SOI Silicon validation test chips include LDPC bloc supplied by the proposed solution. Comparing to the bulk technology, a speed gain of 20% is measured for the same voltage supply and a dynamic power consumption reduction of 30% at same speed is achieved. This solution allows reducing by 2 the static power consumption. Finally, a retention flip-flop associated to the implementation of power switches and optimized in PD-SOI is proposed. This flip-flop is designed to be robust with a low leakage current.Les technologies SOI partiellement désertées (PD-SOI), permettent de gagner en performances ou en consommation dynamique, par rapport à leur équivalent sur substrat massif (BULK). Leur inconvénient principal est la consommation statique qui est bien supérieure, en raison principalement de l'effet de body flottant de ses transistors. Ce travail propose une technique de réduction de la consommation statique, pour la technologie PD-SOI, basée sur le principe des interrupteurs de puissance. Un nouveau facteur de mérite recherchant le meilleur compromis entre vitesse, courant de fuite et surface est introduit pour la sélection du meilleur interrupteur de puissance. L'interrupteur de puissance proposé apporte par rapport à une solution de référence, et pour le même courant de fuite en mode éteint, une réduction de la résistance équivalente en mode passant de 20%. Les tests comparatifs sur Silicium de blocs LDPC incluant ces montages montrent, entre PD-SOI et BULK, un gain de 20% en vitesse pour la même tension d'alimentation, une réduction de 30% de la consommation dynamique pour la même vitesse et une division par 2 de la consommation statique. Enfin, une bascule de rétention, élément à associer aux interrupteurs de puissance, optimisée pour le PD-SOI, est proposée. Cette bascule est conçue de manière robuste et peu fuyante

    reseach on the reduction of the static power dissipation of integrated circuits in 65nm partially depleted Silicon_on_Insulator technology

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    Les technologies SOI partiellement désertées (PD-SOI), permettent de gagner en performances ou en consommation dynamique, par rapport à leur équivalent sur substrat massif (BULK). Leur inconvénient principal est la consommation statique qui est bien supérieure, en raison principalement de l'effet de body flottant de ses transistors. Ce travail propose une technique de réduction de la consommation statique, pour la technologie PD-SOI, basée sur le principe des interrupteurs de puissance. Un nouveau facteur de mérite recherchant le meilleur compromis entre vitesse, courant de fuite et surface est introduit pour la sélection du meilleur interrupteur de puissance. L'interrupteur de puissance proposé apporte par rapport à une solution de référence, et pour le même courant de fuite en mode éteint, une réduction de la résistance équivalente en mode passant de 20%. Les tests comparatifs sur Silicium de blocs LDPC incluant ces montages montrent, entre PD-SOI et BULK, un gain de 20% en vitesse pour la même tension d'alimentation, une réduction de 30% de la consommation dynamique pour la même vitesse et une division par 2 de la consommation statique. Enfin, une bascule de rétention, élément à associer aux interrupteurs de puissance, optimisée pour le PD-SOI, est proposée. Cette bascule est conçue de manière robuste et peu fuyante.Partially depleted SOI technologies (PD-SOI), offer advantages in terms of speed and dynamic power consumption compared to bulk technologies. The main drawback of the PD-SOI technology is its static power consumption, which is higher than bulk one. It is due to the floating body of its transistors. This work presents a new static power consumption design technique based on power switches. A new factor of merit is introduced selecting the power switch with the best trade-off in terms of leakage current, speed and area. A new power switch brings, in comparison to a reference solution, a reduction of 20% of the ON mode equivalent resistance for the same OFF mode leakage current PD-SOI Silicon validation test chips include LDPC bloc supplied by the proposed solution. Comparing to the bulk technology, a speed gain of 20% is measured for the same voltage supply and a dynamic power consumption reduction of 30% at same speed is achieved. This solution allows reducing by 2 the static power consumption. Finally, a retention flip-flop associated to the implementation of power switches and optimized in PD-SOI is proposed. This flip-flop is designed to be robust with a low leakage current
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