Correlation between ground motion and building response using Californian earthquake records

International audienceUsing data from the California Strong Motion Instrumentation Program, we studied the relationship between building response and parameters describing the noxiousness of ground motion. According to vulnerability methods that use structural drift as damage criteria, we estimated the building response on the basis of the normalized relative roof displacement (NRRD), considered as damage criteria. The relationships between the NRRD and the intensity measures of the ground motion are developed using simulated annealing method. Grouping buildings by typology (defined according to their main construction material and height) reduces the variability of the building response. Furthermore, by combining IMs, the NRRD can be predicted more accurately by a Building Damage Prediction Equation. A functional form is thus proposed to estimate the NRRD for several building typologies, calibrated on the building responses recorded in California. This functional form can be used to obtain a fast and overall damage forecast after an earthquake

Synthesis of Complex Subband Hybrid Filter Banks A/D Converters using Adaptive Filters

Hybrid Filter Banks (HFB) A/D converters (ADC) may be an attractive solution for future cognitive radio application. In this paper, using complex adaptive finite impulse response (FIR) filter whose coefficients are initialized with zero, their optimal values are achieved by iterative adjustments. This synthesis method is validated for a complex subband HFB by simulation in the time-domain

Using experimental data to reduce the single-building sigma of fragility curves: case study of the BRD tower in Bucharest, Romania

The lack of knowledge concerning modelling existing buildings leads to significant variability in fragility curves for single or grouped existing buildings. This paper aims to investigate the uncertainties of fragility curves, with special consideration of the single-building sigma. Experimental data and simplified models are applied to the BRD tower in Bucharest (Romania), a RC building with permanent instrumentation. A 3-step methodology is applied, (1) adjustment of a linear MDOF model for experimental modal analysis using a Timoshenko beam model and based on Anderson’s criteria, (2) computation of the structure’s response to a large set of accelerograms simulated by SIMQKE software, considering twelve ground motion parameters as intensity measurements (IM), and (3) construction of the fragility curves by comparing numerical inter-storey drift with the threshold criteria provided by the Hazus methodology for the slight damage state. By introducing experimental data into the model, uncertainty is reduced to 0.02 considering Sd(f1) as seismic intensity IM and uncertainty related to the model is assessed at 0.03. These values must be compared with the total uncertainty value of around 0.7 provided by the Hazus methodology

Synthesis of Subband Hybrid Filter Banks ADCs with Finite Word-length Coefficients using Adaptive Equalization

International audienceSubband Hybrid Filter Banks (SHFB) ADCs are able to convert one or several narrow subbands among a given wideband signal. That provides an appropriate solution to "flexible spectrum" management for cognitive radio applications. In this paper, a SHFB ADC delivering a complex signal is considered. The optimal values of the digital coecients are obtained thanks to an adaptive equalization method. The impact of digital coecients quantization to the SHFB is studied. For a reconstruction quality target, the minimum quantization step is determined. This is validated in time and frequency domain with simulation results

A set of Eurocode 8-compatible synthetic time-series as input to dynamic analysis

International audienceNon-linear dynamic analysis of existing or planned structures often requires the use of accelerograms that match a target design spectrum. Here, our main concern is to generate a set of motions with a good level of fit to the Eurocode 8 (EC8) design spectra for France. Synthetic time series are generated by means of a non-stationary stochastic method. To calibrate the distributions of various strong-motion parameters, we first select a reference set of accelerograms for a type B site category from the PEER Ground-Motion Database, which are then adjusted to the target spectrum through wavelet addition. Finally, we analyse non-linear seismic responses of a soil column including pore pressure effects and ductile structures using these records, revealing considerable variability despite the similarities in terms of spectral acceleration

Sur l'effet des basses températures sur la puissance maximale en sortie d'un amplificateur cohérent en fibre dopée erbium

International audienceThe influence of low temperatures on the performance of a high-power single-frequency fiber laser amplifier is evaluated with a numerical simulation. Cooling the fiber can allow to take advantage of both higher damping of the acoustic waves in the silica glass, and higher laser efficiency. We first report on the measurement of the stimulated Brillouin scattering (SBS) threshold in a silica fiber as a function of the temperature from 300 K down to 77 K. We then present the measurements of small-signal absorption and gain spectra of an erbium doped alumino-phosphosilicate fiber, at room temperature and liquid nitrogen temperature. Based on these data, we derive a numerical study of the combined effects of cooling on the SBS threshold and the amplifier efficiency, and conclude on the interest of this technique for SBS limited high power Er doped fiber amplifiers (EDFA). The temperature increase caused by the pump laser in the fiber core is also addressed

Wide-band multipath A to D converter for Cognitive Radio applications

This article presents a digital-enhanced radio frequency receiver for fast wide-band spectrum sensing. It is based on charge sampling and hybrid filter bank techniques. The charge sampling method is employed to design analog bandpass filters. Using a hybrid filter bank for wide-band analog-to-digital conversion improves the speed and resolution of the conversion. We propose to use these techniques in combination of frequencydivision multiplexing with time-division multiplexing to design an integrated, completely software reconfigurable and reliable backend of radio frequency receiver for cognitive radio applications

Enseignement de la microélectronique à Supélec : Une nouvelle pédagogie mise en place en 2012

National audienceLa rentrée 2012 a été le cadre d’une réforme de l’enseignement de l’électronique intégrée au seinde la majeure MNE (Micro et Nano Electronique) à Supélec. Les objectifs étaient de proposer une nouvelleforme d’enseignement pratique au moyen d’un projet long, de regrouper un ensemble de cours dans unensemble cohérent, de faire intervenir tous les enseignants de l’équipe auprès des élèves dès la rentrée, etsurtout de proposer un maximum de pratique aux élèves de manière à remotiver les élèves autour d’unediscipline qui n’est pas toujours très à la mode dans le monde numérique actuel. L’évaluation des élèves aaussi été repensée de manière à sortir les élèves d’un cadre scolaire et les mettre dans la peau d’unresponsable de projet au sein de l’industrie. L’introduction de points de passage formels avec remise derapports et présentation orale permet aux élèves de découvrir la réalité de leur métier de futur ingénieur. Leretour des élèves a montré que ce nouvel enseignement a été très apprécié de l’ensemble des élèves

A Randomized Trial of Exercise Training Versus Relaxation for the Treatment of Chronic Insomnia in Obstructive Sleep Apnea

Background: Obstructive Sleep Apnea Syndrome (OSA) is a common sleep disorder characterized by partial or complete blockage of the pharyngeal airway during sleep, posing as a significant public health concern. OSA is often comorbid with chronic insomnia (COMISA). Insomnia disorder involves a difficulty initiating sleep, maintaining sleep and/or early awakenings, despite time and opportunity for sleep, causing impairments in daytime functioning and significant distress. Individuals with COMISA suffer from worse sleep and daytime functioning, compared to individuals presenting with either disorder in isolation. Due to their insomnia complaints, these individuals tend to be less compliant with continuous positive airway pressure (CPAP) therapy, the gold standard treatment for OSA. Cognitive behavioural therapy for insomnia (CBTi) has shown promising results in this population but can be difficult for individuals to access, and alone, cannot improve OSA severity. This unique group requires a therapy targeted to both disorders, which would potentially improve apnea-hypopnea index (AHI) and/or insomnia symptomology for a better sleep. Currently, no effective therapy tailored to these individuals has been found. Exercise is a potential non-pharmacological therapy that would simultaneously improve symptoms of both disorders. Studies examining the effects of exercise as a therapy for COMISA are lacking, and research examining exercise as a therapy for either of the two disorders alone yield mixed results likely due to variation in methodology and treatment approach. Objectives: (1) To determine if an 8-week exercise intervention would improve insomnia severity in patients with comorbid OSA and insomnia when compared to an 8-week active control condition of relaxation therapy. (2) To examine the effects of the exercise and relaxation interventions on cardiorespiratory fitness both within-groups and between-groups. (3) To examine if improvements in cardiorespiratory fitness would be associated with improved changes in objective and subjective sleep quality. Methods: Sixteen participants (10 female, 54.9 13.4 years of age) were randomised to 3 weekly sessions of exercise training or self-guided relaxation. The exercise sessions consisted of 60 minutes of moderate-intensity aerobic and resistance exercise, with 1 weekly session supervised and the remaining two unsupervised at home or in the community. The protocol included a screening polysomnography (PSG) night, a cardiopulmonary exercise test, and an overnight PSG, as well as questionnaires (including the Insomnia Severity Index (ISI)) before and after the 8 weeks. All PSG recordings were sampled at 512 Hz (Somnomedics, Germany) and sleep stages were scored offline according to AASM guidelines. ISI and sleep efficiency (SE) (extracted from PSG) were assessed as primary outcomes. VO2peak (ml/kg/min), VO2 at the ventilatory threshold (VT), heart rate (HR) at 50% isotime (ISO) pre- and post- intervention were assessed as secondary outcomes. Bivariate correlations were also performed to examine any potential relationships between change in cardiorespiratory fitness and change in subjective and objective sleep parameters. Results: Results revealed a significant effect of time (pre, post 8-weeks) on ISI score (F(1,14)= 12.315; p=.003), but no significant effect of condition (exercise, relaxation) or time*condition interaction. Both exercise and relaxation had large effects on ISI, with exercise showing a larger effect size (Cohen’s d= 3.88) than relaxation (Cohen’s d= 0.184). No significant effects were found for SE. A significant time*condition interaction was found for VO2peak (ml/kg/min) (F(1,15)= 10.724; p=.006), with the exercise condition showing improvements. Spearman correlations indicated a non-significant association for change in ISI and change in VO2peak (ml/kg/min) (r=0.59; p>.05). Conclusions: Both exercise and relaxation reduced insomnia severity in people with COMISA, with exercise having a larger effect. Objective measures of sleep efficiency did not improve significantly in either group. Cardiorespiratory fitness improved with the partly home-based, moderate-intensity aerobic and resistance training intervention used in this study. Larger trials are warranted to confirm these findings. Significance: This is the first randomized controlled trial (RCT) to examine the effects of an exercise intervention on sleep in this specific COMISA population

Fifteen years of research on oral–facial–digital syndromes: from 1 to 16 causal genes

Oral–facial–digital syndromes (OFDS) gather rare genetic disorders characterised by facial, oral and digital abnormalities associated with a wide range of additional features (polycystic kidney disease, cerebral malformations and several others) to delineate a growing list of OFDS subtypes. The most frequent, OFD type I, is caused by a heterozygous mutation in the OFD1 gene encoding a centrosomal protein. The wide clinical heterogeneity of OFDS suggests the involvement of other ciliary genes. For 15 years, we have aimed to identify the molecular bases of OFDS. This effort has been greatly helped by the recent development of whole-exome sequencing (WES). Here, we present all our published and unpublished results for WES in 24 cases with OFDS. We identified causal variants in five new genes (C2CD3, TMEM107, INTU, KIAA0753 and IFT57) and related the clinical spectrum of four genes in other ciliopathies (C5orf42, TMEM138, TMEM231 and WDPCP) to OFDS. Mutations were also detected in two genes previously implicated in OFDS. Functional studies revealed the involvement of centriole elongation, transition zone and intraflagellar transport defects in OFDS, thus characterising three ciliary protein modules: the complex KIAA0753-FOPNL-OFD1, a regulator of centriole elongation; the Meckel-Gruber syndrome module, a major component of the transition zone; and the CPLANE complex necessary for IFT-A assembly. OFDS now appear to be a distinct subgroup of ciliopathies with wide heterogeneity, which makes the initial classification obsolete. A clinical classification restricted to the three frequent/well-delineated subtypes could be proposed, and for patients who do not fit one of these three main subtypes, a further classification could be based on the genotype