Tone Language Fluency Impairs Pitch Discrimination

Here we present evidence that native speakers of a tone language, in which pitch contributes to word meaning, are impaired in the discrimination of falling pitches in tone sequences, as compared to speakers of a non-tone language. Both groups were presented with monotonic and isochronous sequences of five tones (i.e., constant pitch and intertone interval). They were required to detect when the fourth tone was displaced in pitch or time. While speakers of a tone language performed more poorly in the detection of downward pitch changes, they did not differ from non-tone language speakers in their perception of upward pitch changes or in their perception of subtle time changes. Moreover, this impairment cannot be attributed to poor musical abilities since the impairment remains unchanged when individual differences in musical pitch-based processing is taken into account. Thus, the impairment appears highly specific and may reflect the influence of statistical regularities of tone languages

Analysis of the Dynamic Performance of Serial 3R Orthogonal Manipulators

International audienceSerial 3R orthogonal manipulators have been studied recently and it has been proved that they can exhibit good performances in term of workspace size and kinematic properties. The aim of this work is to analyze their dynamic performances, and compare them with anthropomorphic manipulators, which are very popular in industry. Static and dynamic analyses based on the evaluation of the maximal input torques required for moving the manipulator are achieved. It is shown that, as in kinematics, the dynamic performances of the serial 3R orthogonal manipulators are better

PIV measurements of an air jet impinging on an open rotor-stator system

International audienceThe current work experimentally investigates the flow characteristics of an air jet impinging on an open rotor-stator system with a low non-dimensional spacing, G = 0.02, and with a very low aspect ratio, e/D = 0.25. The rotational Reynolds numbers varied from 33000 to 532000, while the jet Reynolds numbers ranged from 17200 to 43000. Particle image velocimetry (PIV) measurements were taken along the entire disk diameter in three axial planes. From the obtained PIV velocity fields, the flow statistics were computed. A recirculation flow region, which was centered at the impingement point and possessed high turbulence intensities, was observed. Local peaks in root-mean-square fluctuating velocity distributions appeared in the recirculation region and near the periphery, respectively. Proper orthogonal decomposition analysis was applied to the cases of the jet impinging on the rotor with and without rotation to reveal the coherent structures in the jet region

Phase-field simulations of viscous fingering in shear-thinning fluids

A phase-field model for the Hele-Shaw flow of non-Newtonian fluids is developed. It extends a previous model for Newtonian fluids to a wide range of shear-dependent fluids. The model is applied to perform simulations of viscous fingering in shear- thinning fluids, and it is found to be capable of describing the complete crossover from the Newtonian regime at low shear rate to the strongly shear-thinning regime at high shear rate. The width selection of a single steady-state finger is studied in detail for a 2-plateaux shear-thinning law (Carreau law) in both its weakly and strongly shear-thinning limits, and the results are related to previous analyses. In the strongly shear-thinning regime a rescaling is found for power-law (Ostwald-de-Waehle) fluids that allows for a direct comparison between simulations and experiments without any adjustable parameters, and good agreement is obtained

Dynamique d'une interface en présence d'une singularité de contact solide/fluide.

The aim of this work is to achieve a physically relevant modeling removing velocity or vorticity singularities which occur at solid/fluid junctions. These singularities are very common in a number of fluid flows (e.g. lid-driven cavity corners, laterally heated liquid bridges, moving contact lines). It is well known that spectral methods are very sensitive to singularities, and exhibit non physical oscillations (Gibbs Phenomenon) in the vicinity of a discontinuity. For this reason, when using such methods, singular boundary conditions have to be replaced by some regular condition obtained by explicitly filtering the discontinuity. It is less known that finite precision methods (e.g. finite differences, finite volumes, finite elements), though allowing to keep the original conditions, introduce some implicit filter depending on the scale of discretization. In a previous work, evidence was brought up that the local scale of filtering can play a determinant role on the global flow structure. It can, for instance, be responsible for symmetry breaking of the solution in full zone liquid bridge simulations. Assuming that physics is regular, there must exist some mechanism that modifies the fluid's behavior in the region where the classical model fails. Two fundamental questions emerge from these considerations. First, what is the length of the small scale at which physics differs. Second, does there exist some macroscopic model which can incorporate these local effects in macroscopic numerical simulations of continuous medium. This thesis is an attempt to address these two questions.L’objectif de cette thèse a été de montrer qu’il est possible de lever les singularités de vitesse ou de vorticité présentes aux jonctions solide/fluide par une modélisation reposant sur des considérations physiques. Ces singularités interviennent dans un certain nombre de problèmesacadémiques ou d’écoulements modèles en rapport avec une grande variété de configurations (la cavité entraînée, le pont liquide chauffé latéralement, la ligne de contact mobile). Il est bien connu que les méthodes spectrales sont très sensibles aux singularités, ce qui se traduit par laprésence d’oscillations non-physiques (phénomène de Gibbs) au voisinage de la discontinuité. Pour cette raison, pour employer ce type d’approximation numérique, il est nécessaire de remplacer les conditions aux limites singulières par des conditions régulières filtrant explicitementla singularité. Il est moins connu que les méthodes de précision finie (différences finies, volumes finis, éléments finis), qui permettent l’emploi de conditions singulières, introduisent un filtrage implicite de la singularité dépendant de la finesse de résolution spatiale imposée. Des travauxprécédents ont montré que l’échelle de filtrage pouvait influencer la structure de l’écoulement à l’échelle globale. Une des principales motivations de cette thèse a pour origine l’observation que la variation de l’échelle de filtrage peut s’accompagner d’une brisure de symétrie de l’écoulementdans les simulations numériques de pont liquide en zone complète. En partant du principe que la physique est régulière, il devrait exister un mécanisme modifiant le comportement du fluide dans la région où le modèle classique est mis en défaut. On est alors amené à formuler deux questions fondamentales. D’une part, quel est l’ordre de grandeur de la petite échelle à laquelle la physique change ? D’autre part, existe-t-il un modèle macroscopique à même de rendre compte de ces effets locaux dans une simulation numérique du milieu continu

Anomaly detection using Long Short Term Memory Networks and its applications in Supply Chain Management

International audienceAnomaly detection has been becoming an important problem in several domains. In this paper, we propose a new method to detect anomalies in time series based on Long Short Term Memory (LSTM) networks. After being trained on normal data, the networks are used to predict interested steps in time series. The difference between the predicted values and observed values is calculated as prediction errors. Then we use a kernel estimator of the quantile function to compute a threshold, which is used to determine anomalous observations. The performance of proposed method is illustrated through an example of anomaly detection of consumer demand in supply chain management. The numerical experiment shows that our approach achieve a higher level of detection accuracy and a lower percentage of false alarm rate compared to the previous One-Class Support Vector Machine method