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Ridge regression and Kalman filtering for target tracking in wireless sensor networks
No full textInternational audienceThis paper introduces an original method for target tracking in wireless sensor networks that combines machine learning and Kalman filtering. A database of radio-fingerprints is used, along with the ridge regression learning method, to compute a model that takes as input RSSI information, and yields, as output, the positions where the RSSIs are measured. This model leads to a position estimate for each target. The Kalman filter is used afterwards to combine the model's estimates with predictions of the target's positions based on acceleration information, leading to more accurate ones
Analysis of six trace elements (Cd, Cr, Cu, Ni, Pb and Zn) in Diplodus sargus and Siganus rivulatus fish in three sites along the Lebanese coast
No full textInternational audienceThe Lebanese coast is subjected to a strong urban, touristic and industrial pressure. The wastewater of the littoral zone eventually reaches the sea without undergoing, in general, any pretreatment.This precarious situation escalates with the absence of laws that address the "food security" and “environmental” aspects throughout the Lebanese coast or the non-applicationof the existing ones. The fisheries sector inparticular, suffered the consequences. Indeed, in Lebanon, the consumer’s interest for fish is growing. For them the sea products in particularly fish are considered as a healthy food, or even as a luxury food. The sea food restaurants lining the coast are among the most expensive and the most prestigious in the country. But consumer confidence has been eroded by media reports evoking the maritime pollution in the country. It is in this context that we chose to study the metal pollution of two species of fish (Diplodus sargus and Siganus rivulatus) in a region particularly affected by pollution which run from Tabarja to the north of Beirut and end at Ouzaï located at the south of the capital. The captured fishes was completely grounded, lyophilized and mineralized. The mineralization was conducted in a microwave digester. After that, the six trace elements were analyzed by atomic absorption spectroscopy: Cd, Cr, Cu, Ni, Pb and Zn. The obtained results are in general, consistent within international studies : the fish accumulation for the metal contaminants (with exception of Hg) is low. The recorded values are less or equal than the maximum limits in food set by international bodies. Considering the season factor, we note a seasonal fluctuation in the concentration of the studied metals. By comparing the metal level for the three sites, we note that the Ouzaï site is in general, the most polluted one
Ab initio study of MgH2: Destabilizing effects of selective substitutions by transition metals
No full textInternational audienceThe strong ionicity of H within rutile MgH2 is reduced by selective substitution of Mg by T (=Fe, Co, Ni, Pd, Pt) using trirutile super-structure host TMg2H6. These novel model systems, as computed in the quantum mechanical framework of density functional theory, showed a gradual decrease of the charges carried by H down to −0.02e improving the use of MgH2 for applications
Analytical methods for wine polyphenols analysis and for their antioxidant activity evaluation
No full textInternational audienceWine phenolics are of considerable interest and received more and more attention due to their implication in the organoleptic appreciation of wines and to their bioactive functions. Due to their importance in enology sector, there is an increasing demand for highly sensitive and selective analytical methods for the study and assessment of polyphenols. In this chapter, we will review the analytical methods used for polyphenols determination in addition to the methods used for measuring the antioxidant activity
Réajustements des acteurs de la filière oléicole palestinienne face aux dispositifs de séparation israéliens (2002 - 2010)
No full textCe chapitre traite de la façon dont les acteurs du secteur oléicole palestinien composent avec les restrictions de mobilité. Pour ce faire, il s'agira de revenir tout d'abord sur l'ensemble des répercussions des mécanismes de contrôle israéliens sur le développement oléicole cisjordanien. Je montrerai que le confinement de la population auquel ils conduisent bouleverse le rapport à l'espace, au temps, mais aussi à la gestion des plus élémentaires pratiques socio-économiques du quotidien. Pour autant, dans les Territoires Palestiniens comme ailleurs, les murs et les dispositifs associés agissent comme un " appel à la transgression " qui suscite à la fois une redistribution des rôles entre les acteurs et une informalisation des pratiques et des flux économiques. Si l'occupation confisque aux Palestiniens la maîtrise de leur environnement collectif, elle n'annihile pas leur capacité à réorienter, même de façon précaire, leurs trajectoires socio-économiques personnelles. Pour composer avec les contraintes créées par la politique israélienne de séparation, les acteurs œuvrent pour rétablir des marges de mobilité, sinon pour eux pour leurs marchandises, quitte à solliciter pour cela l'entremise d'acteurs très divers. Si ces types de partenariats échappent en grande partie aux dispositifs de contrôle israéliens, il n'y a néanmoins pas lieu de les interpréter comme des actes de " résistance " par l'économie. En effet, ce type de pratiques économiques se développe " vis-à-vis " des dispositifs d'occupation, plutôt qu' " en dehors " et ce faisant, les acteurs concernés entérinent malgré eux le système de contrôle, sans le remettre en cause. Ces réajustements ne défient donc pas l'expression de la domination, mais au contraire en révèlent la profondeur et l'amplitude. Je mettrai l'accent sur les rapports de pouvoir, de dépendance et de complémentarité qui en résultent. Partant de l'étude des transformations des pratiques oléicoles sous l'effet de la politique de séparation, ce travail ouvrira plus globalement sur une analyse de " l'économie de la séparation " dans l'espace israélo-palestinien et sur les relations entre les différents acteurs de cet espace
Drastic changes of electronic structure, bonding properties and crystal symmetry in Zr2Cu by hydrogenation, from ab initio
No full textInternational audienceGradual hydrogen uptake into Zr2Cu intermetallic leads to crystal symmetry changes from tetragonal Zr2CuH2 to monoclinic Zr2CuH5. This experimental finding is explained here from cohesive energies computed within quantum DFT for Zr2CuHx (x = 1, 2, 3, 4, 5) models in both structures. The threshold is found at 2 < x < 3 in agreement with experiment. Beside structural crossover, electronic properties, chemical bonding, and mechanical behavior are also analyzed. Metal-H interactions arising from increasingly H presence in Zr2Cu lead to more and most cohesive and harder Zr2CuH2 and Zr2CuH5 respectively
Continuous-flow microfluidic method for octanol-water partition coefficient measurement
No full textInternational audienc
Diffusion Strategies For In-Network Principal Component Analysis
No full textInternational audienceThis paper deals with the principal component analysis in networks, where it is improper to compute the sample covariance matrix. To this end, we derive several in-network strategies to estimate the principal axes, including noncooperative and cooperative (diffusion-based) strategies. The performance of the proposed strategies is illustrated on diverse applications, including image processing and dimensionality reduction of time series in wireless sensor networks
Target tracking using machine learning and Kalman filter in wireless sensor networks
No full textInternational audienceThis paper describes an original method for target tracking in wireless sensor networks. The proposed method combines machine learning with a Kalman filter to estimate instantaneous positions of a moving target. The target's accelerations, along with information from the network, are used to obtain an accurate estimation of its position. To this end, radio-fingerprints of received signal strength indicators (RSSIs) are first collected over the surveillance area. The obtained database is then used with machine learning algorithms to compute a model that estimates the position of the target using only RSSI information. This model leads to a first position estimate of the target under investigation. The kernel-based ridge regression and the vector-output regularized least squares are used in the learning process. The Kalman filter is used afterward to combine predictions of the target's positions based on acceleration information with the first estimates, leading to more accurate ones. The performance of the method is studied for different scenarios and a thorough comparison with well-known algorithms is also provided