QuickRanking: Fast Algorithm For Sorting And Ranking Data

Fichiers produits par l'auteurQuickRanking: Fast Algorithm For Sorting And Ranking Data QuickRanking is an algorithm that allows in a same processing, to sort the data and to return their ranking, that is to say their rank in the sorting. For faster processing, QuickRanking does not move data, but stores for each data, where the following data is. To evaluate the effectiveness of QuickRanking, I compared with QuickSort on lists of random data.- Sorting and classification of digital data: QuickSort is more efficient than QuickRanking only on large lists of data. QuickRanking takes the advantage in other cases. Advantage emphasised when the data at the beginning of the list are already classified, when the list is made up of few different values, or when the minimum or maximum value is often represented.- Sorting and classification of alphanumeric data, or sorting only: QuickRanking is often faster than QuickSort. Advantage emphasised on the processing of large chains of characters. Conclusion: ideally random list or highly classified list, large data or reduced size data, numeric or alphanumeric data, the reality is often between these extremes. In practice, QuickRanking may provide an interesting alternative to QuickSort. All information is in the attachment

Ordered arrays of magnetic nanowires investigated by polarized small-angle neutron scattering

Polarized small-angle neutron scattering (PSANS) experimental results obtained on arrays of ferromagnetic Co nanowires ($\phi\approx13$ nm) embedded in self-organized alumina (Al$_{2}$O$_{3}$) porous matrices are reported. The triangular array of aligned nanowires is investigated as a function of the external magnetic field with a view to determine experimentally the real space magnetization $\vec{M}(\vec{r})$ distribution inside the material during the magnetic hysteresis cycle. The observation of field-dependentSANSintensities allows us to characterize the influence of magnetostatic fields. The PSANS experimental data are compared to magnetostatic simulations. These results evidence that PSANS is a technique able to address real-space magnetization distributions in nanostructured magnetic systems. We show that beyond structural information (shape of the objects, two-dimensional organization) already accessible with nonpolarized SANS, using polarized neutrons as the incident beam provides information on the magnetic form factor and stray fields \textgreek{m}0Hd distribution in between nanowires.Comment: 13 pages, 10 figures, submitted to Phys. Rev.

Le cœur de l'éducation est soin

     Pour  un jeune passionné d'éducation, la première rencontre avec l'autre se fait souvent en lien avec la prise en compte d'un corps souffrant. Comment, dès lors, le soin directement apporté au corps de l'autre devient-il métaphore, d'un autre soin, celui de la pensée? Et comment l'éducation, abordée depuis cette expérience devient éducation au soin de l'autre tout au long de sa vie? Voilà quelques pistes abordées par ce texte

QuickRanking : Algorithme Rapide de Classement

QuickRanking est un algorithme qui permet dans un même traitement, de trier les données et de retourner leur ordre de classement, c’est-à-dire leur rang dans le tri.Pour des traitements plus rapides, QuickRanking ne déplace pas les données, mais mémorise pour chaque donnée, où est la donnée qui la suit. Cette méthode est expliquée en Annexe 1. Le code est en annexe 2.Pour évaluer l’efficacité de QuickRanking, j’ai reproduit en annexe 3 le code source de QuickSort, et en annexe 4 une version « enrichie » de QuickSort, que j’ai appelée QuickSort_AndRank, qui à l’instar de QuickRanking, ne déplace pas directement les données mais déplace les références des indices des données. D’où un gain de temps sur les traitements des données alphanumériques volumineuses car l’on déplace des entiers de 4 octets et non plus des chaînes de caractères de longueurs variables. Cela nécessite des capacités mémoire supplémentaires, mais permet du coup d’utiliser ces tableaux de référence pour retourner un ordre de classement en plus du tri, tout comme le fait QuickRanking.J’ai comparé ces trois algorithmes - QuickSort (tri simple), QuickSort_AndRank, et QuickRanking (tri et classement) - les résultats sont synthétisés dans un tableau en annexe 5. Mon analyse est la suivante pour le traitement de tri et le classement des données :- Données numériques : QuickSort_AndRank est plus rapide que QuickRanking uniquement sur les grandes listes de données. QuickRanking prend l’avantage dans les autres cas. Avantage accentué lorsque les données en début de liste sont déjà classées, lorsque la liste est composée de peu de valeurs différentes, ou lorsque la valeur minimale ou maximale est souvent représentée.- Données Alphanumériques : QuickRanking est plus rapide que QuickSort_AndRank. Avantage accentué sur le traitement des grandes chaînes de caractères. Conclusion : liste idéalement aléatoire ou liste fortement classée, données volumineuses ou de taille réduite, la réalité se situe souvent entre ces extrêmes. Dans la pratique, QuickRanking offre alors une alternative intéressante… Remarques :- Vous trouverez plus d'informations dans le fichier PDF joint.- Le fichier EXCEL joint reprend ces algorithmes.- Les tests ont été réalisés sur un PC bureautique en VBA sous EXCEL. Les résultats sont donnés à titre indicatifs, l’objectif étant de faire ressortir une tendance. Ces résultats devront être confirmés dans d’autres langages de programmation et avec d’autres systèmes d’exploitation. Je recherche des volontaires si l'aventure vous tente.- Cette version 4, plus performante que les versions précédentes, dispose aussi en option d'analyses supplémentaires pour accélérer les traitements sur les listes partiellement classées

Le cœur de l'éducation est soin

     Pour  un jeune passionné d'éducation, la première rencontre avec l'autre se fait souvent en lien avec la prise en compte d'un corps souffrant. Comment, dès lors, le soin directement apporté au corps de l'autre devient-il métaphore, d'un autre soin, celui de la pensée? Et comment l'éducation, abordée depuis cette expérience devient éducation au soin de l'autre tout au long de sa vie? Voilà quelques pistes abordées par ce texte

Charactérisation à haute fréquence d'un jet balayant

International audienceSweeping jets are an emerging type of actuators that have gained interest due to their potential use in flow control applications. The working principle of these devices is based on the bi-stable attachment of a jet to adjacent walls. They are able to produce unsteady blowing within a wide range of operating frequencies. Nevertheless, the state of art shows a lack of space-time characterization of these actuators for high sweeping frequencies. This paper resents a conditional approach that reconstructs the spatial dynamic response of sweeping jets for sweeping frequencies above 500 Hz. The time-dependent velocity is measured with two single-hot-wire sensors: a reference one placed at the edge of the exit nozzle, and a flying one. The method is then tested to characterize the flow at the exit nozzle of an in-house sweeping jet actuator with 1mm space resolution, and 50 µs time resolution. These measurements are performed with a sweeping frequency of 639 Hz. Overall this paper demonstrates that the conditional approach is very useful for understanding the physics of flow control actuators.Les jets balayants sont des actionneurs fluidiques en pleine extension dans le domaine du contrôle actif des écoulements de par leur large gamme de fréquences et de vitesses. Ils se basent sur le phénomène de bi-stabilité de détachement de l'écoulement sur les parois interne de l'actionneur. Cependant la littérature montre une faiblesse pour la caractérisation expérimentale à haute fréquence de l'écoulement en sortie d'actionneur. Ce papier présente une méthode de reconstruction résolue en espace et en temps, basée sur une approche conditionnelle permettant de reconstruire l'écoulement pour des fréquence de balayage supérieures à 500Hz. Les signaux de vitesse résolus en temps sont mesurés à l'aide de deux fils chauds : un fixe pour le signal de synchronisation et un mobile, se déplaçant sur un maillage de finesse 1mm. Cette méthode est ensuite appliquée à un actionneur de jet balayant fonctionnant a une fréquence de 639Hz, avec un signal de vitesse de résolution temporelle de 50 micro secondes. Ce papier démontre ainsi que l'approche conditionnelle peut être utilisable pour comprendre la physique des écoulements en sortie d'actionneurs fluidiques

Music and Metronomes Differentially Impact Motor Timing in People with and without Parkinson's Disease: Effects of Slow, Medium, and Fast Tempi on Entrainment and Synchronization Performances in Finger Tapping, Toe Tapping, and Stepping on the Spot Tasks

© 2019 Dawn Rose et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (https://creativecommons.org/licenses/by/4.0/).Introduction: Rhythmic Auditory Stimulation (RAS) has successfully helped regulate gait for people with Parkinson’s disease. However, the way in which different auditory cues and types of movements affect entrainment, synchronization and pacing stability has not been directly compared in different aged people with and without Parkinson's. Therefore, this study compared music and metronomes (cue types) in finger tapping, toe tapping and stepping on the spot tasks to explore the potential of RAS training for general use.Methods: Participants (aged 18-78 years) included people with Parkinson’s (n=30, Hoehn & Yahr Mean=1.78), Older (n=26), and Younger adult controls (n=36), as age may effect motor timing. Timed motor production was assessed using an extended synchronization-continuation task in cue type and movement conditions for slow, medium and fast tempi (81, 116 and 140 mean beats-per-minute respectively).Results: Analyses revealed main effects of cue and movement type but no between group interactions, suggesting no differences in motor timing between people with Parkinson's and controls. Music supported entrainment better than metronome in medium and fast tempi, and stepping on the spot enabled better entrainment and less asynchrony, as well as more stable pacing compared to tapping in medium and fast tempi. Age was not confirmed as a factor and no differences were observed in slow tempo.Conclusion: This is the first study to directly compare how different external auditory cues and movement types affect motor timing. The music and the stepping enabled participants to maintain entrainment once the external pacing cue ceased, suggesting endogenous mechanisms continued to regulate the movements. The superior performance of stepping on the spot suggests embodied entrainment can occur during continuous movement, and this may be related to emergent timing in tempi above 600 ms. These findings can be applied therapeutically to manage and improve adaptive behaviours for people with Parkinson’s.Peer reviewe

Gestures convey different physiological responses when performed toward and away from the body

We assessed the sympathetic and parasympathetic activation associated to the observation of Pantomime (i.e. the mime of the use of a tool) and Intransitive gestures (i.e. expressive) performed toward (e.g. a comb and "thinking") and away from the body (e.g. key and "come here") in a group of healthy participants while both pupil dilation (N = 31) and heart rate variability (N = 33; HF-HRV) were recorded. Large pupil dilation was observed in both Pantomime and Intransitive gestures toward the body; whereas an increase of the vagal suppression was observed in Intransitive gestures away from the body but not in those toward the body. Our results suggest that the space where people act when performing a gesture has an impact on the physiological responses of the observer in relation to the type of social communicative information that the gesture direction conveys, from a more intimate (toward the body) to a more interactive one (away from the body).We would like to thank Johanna Viana, Raphael Kroll and Alberto Villar for their precious help in the task construction and in the recruitment of participants. We also thank all the participants that entered the study. This work was funded by the French National Research Agency (ANR-11-EQPX-0023) and supported by European funds through the program FEDER SCV-IrDIVE. This study was partially conducted at the Psychology Research Centre (PSI/01662), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education (UID/PSI/01662/2019), through the national funds (PIDDAC)

A general procedure to measure the pacing of body movements timed to music and metronome in younger and older adults

© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Finger-tapping tasks are classically used to investigate sensorimotor synchronization in relation to neutral auditory cues, such as metronomes. However, music is more commonly associated with an entrained bodily response, such as toe tapping, or dancing. Here we report an experimental procedure that was designed to bridge the gap between timing and intervention studies by directly comparing the effects of metronome and musical cue types on motor timing abilities across the three naturalistic voluntary actions of finger tapping, toe tapping, and stepping on the spot as a simplified case of whole body movement. Both pacing cues were presented at slow, medium, and fast tempi. The findings suggested that the task of stepping on the spot enabled better timing performances than tapping both in younger and older adults (75+). Timing performances followed an inverse U shape with best performances observed in the medium tempi that were set close to the spontaneous motor tempo in each movement type. Finally, music provided an entrainment effect in addition to pace setting that enabled better motor timing and greater stability than classically reported using a metronome. By applying time-stamp analyses to kinetic data, we demonstrate that tapping and stepping engage different timing modes. This work details the importance of translational research for a better understanding of motor timing. It offers a simple procedure that strengthens the validity of applying academic work and contributes in knowledge towards a wide range of therapeutic interventions.Peer reviewe

PHARAO Laser Source Flight Model: Design and Performances

In this paper, we describe the design and the main performances of the PHARAO laser source flight model. PHARAO is a laser cooled cesium clock specially designed for operation in space and the laser source is one of the main sub-systems. The flight model presented in this work is the first remote-controlled laser system designed for spaceborne cold atom manipulation. The main challenges arise from mechanical compatibility with space constraints, which impose a high level of compactness, a low electric power consumption, a wide range of operating temperature and a vacuum environment. We describe the main functions of the laser source and give an overview of the main technologies developed for this instrument. We present some results of the qualification process. The characteristics of the laser source flight model, and their impact on the clock performances, have been verified in operational conditions.Comment: Accepted for publication in Review of Scientific Instrument