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Le faible niveau de variabilité morphométrique et la faible information phylogénétique portée par les caractères morpho-anatomiques utilisés à ce jour dans la systématique des mulets (Mugilidae) montrent l’intérêt de la systématique moléculaire dans cette famille. Une phylogénie mitochondriale récente de la famille des Mugilidae a montré de multiples lignées profondes au sein de plusieurs espèces, signalant de possibles espèces cryptiques. Ici, nous avons considéré que plusieurs de ces lignées profondes représentaient des espèces distinctes en nous basant, soit sur la topologie de l'arbre, soit sur des données génétiques nucléaires obtenues indépendamment, soit sur les distributions géographiques. Par analogie avec ces cas bien documentés, nous avons examiné d'autres lignées profondes dans sept genres sur lesquels nous avions concentré...
International audience
International audience
International audience
We study a class of stochastic differential equations driven by a possibly tempered Lévy process, under mild conditions on the coefficients. We prove the well-posedness of the associated martingale problem as well as the existence of the density of the solution. Two sided heat kernel estimates are given as well. Our approach is based on the Parametrix series expansion
An X/Ka-band (8.4/32 GHz) celestial reference frame has been constructed using single baselines from the combined NASA and ESA Deep Space Networks for approximately 100 sessions each of ∼24-hour duration. The frame solution has dramatically improved with respect to the last reported frame due to the inclusion of Southern NASA-ESA baselines, routine 2-Gbps data rates, and correction of instrumental delays by recently deployed Ka-band phase calibration tones. Comparisons with the S/X-band (2.3/8.4 GHz) ICRF-2 reference frame will be presented showing increasing agreement for 525 common sources. About 135 sources are located in the south polar cap (δ < −45◦) which became accessible for first time with the addition of the ESA station in Malargüe, Argentina to our project’s network. There is evidence for systematic errors at the 100 μas lev...
In domains where robots carry out human’s tasks, the ability to learn new behaviors easily and quickly plays an important role. Two major challenges with Learning from Demonstration (LfD) are to identify what information in a demonstrated behavior requires attention by the robot, and to generalize the learned behavior such that the robot is able to perform the same behavior in novel situations.The main goal of this paper is to incorporate Ant Colony Optimization (ACO) algorithms into LfD in an approach that focuses on understanding tutor’s intentions and learning conditions to exhibit a behavior. The proposed method combines ACO algorithms with semantic networks and spreading activation mechanism to reason and generalize the knowledge obtained through demonstrations. The approach also provides structures for behavior reproduction under...
