Multiple kernel learning SVM and statistical validation for facial landmark detection

Abstract — In this paper we present a robust and accurate method to detect 17 facial landmarks in expressive face images. We introduce a new multi-resolution framework based on the recent multiple kernel algorithm. Low resolution patches carry the global information of the face and give a coarse but robust detection of the desired landmark. High resolution patches, using local details, refine this location. This process is combined with a bootstrap process and a statistical validation, both improving the system robustness. Combining independent point detection and prior knowledge on the point distribution, the proposed detector is robust to variable lighting conditions and facial expressions. This detector is tested on several databases and the results reported can be compared favorably with the current state of the art point detectors. I

Combinaison de Descripteurs Hétérogènes pour la Reconnaissance de Micro-Mouvements Faciaux

Session "Posters"National audienceDans cet article, nous présentons notre réponse au premier challenge international sur la reconnaissance et l'analyse d'émotions faciales (Facial Emotion Recognition and Analysis Challenge). Nous proposons une combinaison de dif- férents types de descripteurs dans le but de détecter de manière automatique, les micro-mouvements faciaux d'un visage. Ce système utilise une Machine à Vecteurs Supports Multi-Noyaux pour chacune des Action Units (AU) que nous désirons détecter. Le premier noyau est calculé en utilisant des histogrammes de motifs binaires locaux de Gabor (ou Local Gabor Binary Pattern, LGBP) via un noyau d'intersection d'histogramme. Le second noyau quant à lui, est crée avec des coefficients de Modèles Actifs d'Apparence via un noyau gaussien. Les sorties de chacune des SVM sont ensuite filtrées dans le but d'inclure l'informa- tion temporelle de la séquence. Afin d'évaluer notre système, nous avons procédé à de nombreuses expérimentations sur plusieurs points clefs de notre méthode. Enfin, nous comparons nos résultats à ceux obtenus par les autres participants au challenge, tout en analysant nos performanche

Facial Action Recognition Combining Heterogeneous Features via Multi-Kernel Learning

International audienceThis paper presents our response to the first interna- tional challenge on Facial Emotion Recognition and Analysis. We propose to combine different types of features to automatically detect Action Units in facial images. We use one multi-kernel SVM for each Action Unit we want to detect. The first kernel matrix is computed using Local Gabor Binary Pattern histograms and a histogram intersection kernel. The second kernel matrix is computed from AAM coefficients and an RBF kernel. During the training step, we combine these two types of features using the recently proposed SimpleMKL algorithm. SVM outputs are then averaged to exploit temporal information in the sequence. To eval- uate our system, we perform deep experimentations on several key issues: influence of features and kernel function in histogram- based SVM approaches, influence of spatially-independent in- formation versus geometric local appearance information and benefits of combining both, sensitivity to training data and interest of temporal context adaptation. We also compare our results to those of the other participants and try to explain why our method had the best performance during the FERA challenge

Lithium-6 from Solar Flares

By introducing a hitherto ignored Li-6 producing process, due to accelerated He-3 reactions with He-4, we show that accelerated particle interactions in solar flares produce much more Li-6 than Li-7. By normalizing our calculations to gamma-ray data we demonstrate that the Li-6 produced in solar flares, combined with photospheric Li-7, can account for the recently determined solar wind lithium isotopic ratio, obtained from measurements in lunar soil, provided that the bulk of the flare produced lithium is evacuated by the solar wind. Further research in this area could provide unique information on a variety of problems, including solar atmospheric transport and mixing, solar convection and the lithium depletion issue, and solar wind and solar particle acceleration.Comment: latex 9 pages, 2 figures, ApJ Letters in pres

Dynamics of a pre-stalled windturbine blade using control of circulation at the trailing-edge

Wind turbines are installed in the strongly inhomogeneous and unsteady turbulent atmospheric boundary layer. This induces unsteady mechanical loads at different characteristic time scales from seconds to minutes which limit significantly their life time. The present work, supported by the SMARTEOLE ANR project, focuses on the flow control strategies at the blade scale, to manipulate lift and thus alleviate some of these loads. For this purpose, a NACA654-421 airfoil profile has been modified : the trailing edge has been rounded to take advantage of Coanda effects and the camber has been increased to compensate the loss of lift due to the trailing edge modifications. The lift control is obtained by fluidic injection via 42 1x1 mm micro-jets placed at the trailing edge along the entire span of the wing. An experiment has been conducted to identify both static and dynamic performances of the proposed control mechanism. The experimental campaign consisted in chordwise unsteady pressure measurements as well as aerodymics forces measurements. The preliminary results of the mean quantities indicate that the lift gain obtained is proportional to the fluidic injection, which is of interest when closed-loop control is to be considered. In a second series of measurements, we focus on the step-response of the flow to the actuation. The lift response is shown to behave as a first order dynamics and we show that the response time of lift is of the order of 3 convective time units. This is about three times faster than what is usually observed for boundary layer reattachement process

Comparing Measurements of Vascular Diameter Using Adaptative Optics Imaging and Conventional Fundus Imaging

The aim of this prospective study was to compare retinal vascular diameter measurements taken from standard fundus images and adaptive optics (AO) images. We analysed retinal images of twenty healthy subjects with 45-degree funduscopic colour photographs (CR-2 Canon fundus camera, Canon™) and adaptive optics (AO) fundus images (rtx1 camera, Imagine Eyes(®)). Diameters were measured using three software applications: the VAMPIRE (Vessel Assessment and Measurement Platform for Images of the REtina) annotation tool, IVAN (Interactive Vessel ANalyzer) for funduscopic colour photographs, and AO_Detect_Artery™ for AO images. For the arterial diameters, the mean difference between AO_Detect_Artery™ and IVAN was 9.1 µm (−27.4 to 9.2 µm, p = 0.005) and the measurements were significantly correlated (r = 0.79). The mean difference between AO_Detect_Artery™ and VAMPIRE annotation tool was 3.8 µm (−34.4 to 26.8 µm, p = 0.16) and the measurements were poorly correlated (r = 0.12). For the venous diameters, the mean difference between the AO_Detect_Artery™ and IVAN was 3.9 µm (−40.9 to 41.9 µm, p = 0.35) and the measurements were highly correlated (r = 0.83). The mean difference between the AO_Detect_Artery™ and VAMPIRE annotation tool was 0.4 µm (−17.44 to 25.3 µm, p = 0.91) and the correlations were moderate (r = 0.41). We found that the VAMPIRE annotation tool, an entirely manual software, is accurate for the measurement of arterial and venular diameters, but the correlation with AO measurements is poor. On the contrary, IVAN, a semi-automatic software tool, presents slightly greater differences with AO imaging, but the correlation is stronger. Data from arteries should be considered with caution, since IVAN seems to significantly under-estimate arterial diameters

Sensibilidades socio-raciales en el Atlántico Hispano. Posturas anti-esclavistas, empatías ideológicas y actitudes temerosas hacia los sectores subalternos de color en España e Hispanoamérica a fines de la edad moderna

This article studies from a longue durée perspective the articulation of anti-slavery sentiments and other socio-racial sensibilities within the Spanish Atlantic, from the first theological criticisms of the 16th century to the efforts to abolish slavery in Cuba, Puerto Rico and Spain, in the second half of the 19th century. We focus on the most significant cases of individuals who shared a white identity and who advocated against slavery, slave trade and socio-racial discrimination of Free Coloureds. We argue that the many egalitarian proposals made during the Spanish American revolutions and at the Cortes of Cádiz represent a second golden moment (after the ‘Mulatto Affaire’ during the French Revolution) in the struggle for the granting of political equality to subaltern sectors the Atlantic World. In the end, we expect to provide a clearer picture of how the socio-racial sensibilities contributed to accelerate, or to postpone, the introduction of abolitionist or equalitarian measures vis-à-vis the coloured subaltern sectors in the Spanish Atlantic in the Late Modern Age.Este artículo estudia desde una perspectiva de longue durée la articulación de los sentimientos anti-esclavistas con otras sensibilidades socio-raciales en el Atlántico español, desde las primeras críticas teológicas del siglo xvi hasta los esfuerzos para abolir la esclavitud en Cuba, Puerto Rico y España, en la segunda mitad del siglo XIX. El estudio se centra en los casos más significativos de individuos que compartían una identidad blanca y que abogaron contra la esclavitud, la trata de esclavos y la discriminación socio-racial de los libres de color. El mismo sostiene que las muchas propuestas igualitarias hechas durante las revoluciones hispanoamericanas y en las Cortes de Cádiz representan un segundo momento dorado (después del llamado ‘Asunto de los mulatos’ durante la Revolución Francesa) en la lucha por el otorgamiento de igualdad política a los sectores subalternos en el Mundo Atlántico. Al final, se aspira proporcionar una imagen más clara de cómo las sensibilidades socio-raciales contribuyeron a acelerar, o posponer, la introducción de medidas abolicionistas e igualitarias para los sectores subalternos de color en el Atlántico español a fines de la Edad Moderna

A Novel fry1 Allele Reveals the Existence of a Mutant Phenotype Unrelated to 5′->3′ Exoribonuclease (XRN) Activities in Arabidopsis thaliana Roots

BACKGROUND Mutations in the FRY1/SAL1 Arabidopsis locus are highly pleiotropic, affecting drought tolerance, leaf shape and root growth. FRY1 encodes a nucleotide phosphatase that in vitro has inositol polyphosphate 1-phosphatase and 3',(2'),5'-bisphosphate nucleotide phosphatase activities. It is not clear which activity mediates each of the diverse biological functions of FRY1 in planta. PRINCIPAL FINDINGS A fry1 mutant was identified in a genetic screen for Arabidopsis mutants deregulated in the expression of Pi High affinity Transporter 1;4 (PHT1;4). Histological analysis revealed that, in roots, FRY1 expression was restricted to the stele and meristems. The fry1 mutant displayed an altered root architecture phenotype and an increased drought tolerance. All of the phenotypes analyzed were complemented with the AHL gene encoding a protein that converts 3'-polyadenosine 5'-phosphate (PAP) into AMP and Pi. PAP is known to inhibit exoribonucleases (XRN) in vitro. Accordingly, an xrn triple mutant with mutations in all three XRNs shared the fry1 drought tolerance and root architecture phenotypes. Interestingly these two traits were also complemented by grafting, revealing that drought tolerance was primarily conferred by the rosette and that the root architecture can be complemented by long-distance regulation derived from leaves. By contrast, PHT1 expression was not altered in xrn mutants or in grafting experiments. Thus, PHT1 up-regulation probably resulted from a local depletion of Pi in the fry1 stele. This hypothesis is supported by the identification of other genes modulated by Pi deficiency in the stele, which are found induced in a fry1 background. CONCLUSIONS/SIGNIFICANCE Our results indicate that the 3',(2'),5'-bisphosphate nucleotide phosphatase activity of FRY1 is involved in long-distance as well as local regulatory activities in roots. The local up-regulation of PHT1 genes transcription in roots likely results from local depletion of Pi and is independent of the XRNs.This work was supported by an ANR-GENOPLANT grant (RIBOROOT-ANR06 GPLA 011) and the CEA agency. Array hybridizations have been partly supported by RNG (Réseau National des Génopoles, Evry, France). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding received for this study

Analyse numérique du fluage et de la recouvrance d'un contact viscoélastique

Des essais de fluage de contact et de recouvrance des empreintes ont été réalisés pour analyser la "cicatrisation" d'une surface de PMMA sollicitée en microindentation par une bille rigide. Les résultats sont analysés avec des simulations numériques. L'identification du comportement viscoélastique du PMMA est obtenue à partir d'essais de relaxation. Les résultats permettent d'analyser les champs de déformation sous le contact lors de la phase de fluage. Ceux-ci montrent que la localisation du niveau maximal de déformation est prépondérante dans le caractère cicatrisant d'une empreinte