Audio Event Detection in Movies using Multiple Audio Words and Contextual Bayesian Networks

International audienceThis article investigates a novel use of the well known audio words representations to detect specific audio events, namely gunshots and explosions, in order to get more robustness towards soundtrack variability in Hollywood movies. An audio stream is processed as a sequence of stationary segments. Each segment is described by one or several audio words obtained by applying product quantization to standard features. Such a representation using multiple audio words constructed via product quantisation is one of the novelties described in this work. Based on this representation, Bayesian networks are used to exploit the contextual information in order to detect audio events. Experiments are performed on a comprehensive set of 15 movies, made publicly available. Results are comparable to the state of the art results obtained on the same dataset but show increased robustness to decision thresholds, however limiting the range of possible operating points in some conditions. Late fusion provides a solution to this issue

De la détection d'évènements sonores violents par SVM dans les films

National audienceThis article studies the behaviour of a state-of-the-art support vector machine audio event detection approach, applied to violent event detection in movies. The events we are trying to detect are screams, gunshots, explosions. Contrary to others studies, we show that the state-of-theart approach does not lead to good results on this task. A study on the repartition of samples into subsets in a cross validation protocol helps explain those results and highlights a generalisation problem due to a polymorphism of considered classes. This polymorphism is demonstrated by the computation the divergence between the samples of the test database and the training database.Cet article étudie le comportement d'une approche classique, à l'état de l'art, pour la détection d'événements sonores par machines à vecteurs supports, appliquée à la détection d'événements violents dans les films. Les événements sonores considérés, liés à la présence de violence, sont les Cris, les Coups de feu et les Explosions. Nous montrons que, contrairement aux résultats d'autres études, l'approche état de l'art ne donne pas de bons résultats sur cette tâche. Une étude sur la répartition des échantillons en sous-ensembles dans un protocole de validation croisée permet d'expliquer ces résultats et met en évidence un problème de généralisation, dû au polymorphisme des classes considérées. Ce polymorphisme est démontré par un calcul de divergence entre les échantillons de la base de test et ceux de la base d'apprentissage

The twitaholic next door.: scalable friend recommender system using a concept-sensitive hash function

International audienceIn this paper we present a Friend Recommender System for micro-blogging. Traditional batch processing of mas- sive amounts of data makes it di cult to provide a near- real time friend recommender system or even a system that can properly scale to millions of users. In order to over- come these issues, we have designed a solution that repre- sents user-generated micro posts as a set of pseudo-cliques. These graphs are assigned a hash value using an original Concept-Sensitive Hash function, a new sub-kind of Locally- Sensitive Hash functions. Finally, since the user pro les are represented as a binary footprint, the pairwise comparison of footprints using the Hamming distance provides scalability to the recommender system. The paper goes with an online application relying on a large Twitter dataset, so that the reader can freely experiment the system

Structuration multimodale d'une vidéo de tennis par modèles de Markov cachés

- Cet article présente une méthode de structuration d'une vidéo utilisant des indices sonores et visuels. Cette méthode repose sur un modèle statistique de l'entrelacement temporel des plans de la vidéo. Le cadre général de la modélisation est celui des modèles de Markov cachés. L'approche est validée dans le cadre de vidéos de tennis télédiffusées. Les indices visuels sont utilisés pour caractériser le type des plans. Les indices audio décrivent les événements sonores apparaissant durant un plan. La structure de la vidéo est représentée par un modèle de Markov caché, intégrant les informations a priori sur le contenu de la vidéo, ainsi que sur les règles d'édition. En résultat du décodage, des éléments structuraux caractéristiques du tennis sont identifiés: premier service raté, échange, rediffusion ou temps mort. De plus, chaque plan de la vidéo est assigné à un niveau de hiérarchie décrit en terme de point, jeu et set. Cette classification et segmentation simultanées peuvent être utilisées pour la création de résumés vidéo ou pour permettre une navigation non linéaire dans le document vidéo

MULTIMODAL INFORMATION FUSION AND TEMPORAL INTEGRATION FOR VIOLENCE DETECTION IN MOVIES

International audienceThis paper presents a violent shots detection system that studies several methods for introducing temporal and multimodal information in the framework. It also investigates different kinds of Bayesian network structure learning algorithms for modelling these problems. The system is trained and tested using the MediaEval 2011 Affect Task corpus, which comprises of 15 Hollywood movies. It is experimentally shown that both multimodality and temporality add interesting information into the system. Moreover, the analysis of the links between the variables of the resulting graphs yields important observations about the quality of the structure learning algorithms. Overall, our best system achieved 50% false alarms and 3% missed detection, which is among the best submissions in the MediaEval campaign

Technicolor and INRIA/IRISA at MediaEval 2011: learning temporal modality integration with Bayesian Networks

International audienceThis paper presents the work done in Technicolor and INRIA regarding the A ffect Task at MediaEval 2011. This task aims at detecting violent shots in movies. We studied a bayesian network framework, and several ways of introducing temporality and multimodality in the framework

Recycle System Design for End-of-Life Electronics in Developing Countries

This paper examines recycling of end-of-life products in developing countries to determine the most reasonable collection policy in order to increase profits. The process of self-recycling by original manufacturers is examined using simulations. The simulations were based on three different investment percentage collection/remanufacture policies for end-of-life products. Results offered here can help decision makers understand tradeoffs they face as they decide how to best process turned products (refurbish, remanufacture, or recycle). Results from simulations presented in this paper can help firms in developing countries understand and improve their recycling processes. Simulation of the various collection policies for end-of-life products shows that low-end collection policies provide the better profit results. Following the policies given by the results of the simulations should improve profits and efficiencies for companies in developing countries and help them understand the benefits of recycling

West Nile Virus in Horses, sub-Saharan Africa

To evaluate the presence and extension of West Nile virus where French soldiers are stationed in Africa, specific antibody prevalence was determined by using ELISA and Western blot. Among 245 horses living in close proximity to the soldiers, seroprevalence was particularly high in Chad (97%) and Senegal (92%)

Seebeck Effect in Magnetic Tunnel Junctions

Creating temperature gradients in magnetic nanostructures has resulted in a new research direction, i.e., the combination of magneto- and thermoelectric effects. Here, we demonstrate the observation of one important effect of this class: the magneto-Seebeck effect. It is observed when a magnetic configuration changes the charge based Seebeck coefficient. In particular, the Seebeck coefficient changes during the transition from a parallel to an antiparallel magnetic configuration in a tunnel junction. In that respect, it is the analog to the tunneling magnetoresistance. The Seebeck coefficients in parallel and antiparallel configuration are in the order of the voltages known from the charge-Seebeck effect. The size and sign of the effect can be controlled by the composition of the electrodes' atomic layers adjacent to the barrier and the temperature. Experimentally, we realized 8.8 % magneto-Seebeck effect, which results from a voltage change of about -8.7 {\mu}V/K from the antiparallel to the parallel direction close to the predicted value of -12.1 {\mu}V/K.Comment: 16 pages, 7 figures, 2 table

O'nyong-nyong Virus, Chad

We report the first laboratory-confirmed human infection with O'nyong-nyong virus in Chad. This virus was isolated from peripheral blood mononuclear cells of a patient with evidence of a seroconversion to a virus related to Chikungunya virus. Genome sequence was partly determined, and phylogenetic studies were conducted