Pistage 3D par mesures angulaires sans manœuvres

International audiencePassive target estimation is a widely investigated problem of practical interest. We are concerned specifically with an autonomous flight system developed onboard the ONERA ReSSAC unmanned helicopter. This helicopter is equipped with a (visible or infrared) camera and so is able to measure azimuths and elevation angles of a target. The latter is supposed to follow a constant velocity motion. It is well known that observer must maneuver in order to insure the observability of the target state. We are interested in tracking partly the target state when both the observer and the target have a constant velocity model in a three-dimensional space. We describe the set of all the trajectories compatible with the angle measurements and we propose a quick method to estimate these trajectories.Le pistage passif d'une cible est un domaine de recherche actif. Nous nous intéressons particulièrement au drone hélicoptère Ressac. Celui-ci est équipé d'une caméra optique et infrarouge. Il est donc capable d'effectuer des mesures angulaires (azimuts et sites) d'une cible. Cette cible est supposée suivre une mouvement rectiligne uniforme dans l'espace. Il est bien connu que l'observateur doit manœuvrer pour pour assurer l'observabilité de l'état de la cible. Dans ce papier, nous estimons partiellement cet état lorsque la cible et l'observateur sont en mouvement rectiligne uniforme dans l'espace 3D. Nous décrivons l'ensemble des trajectoires cible compatibles avec ces mesures angulaires et nous proposons une méthode rapide d'estimations de ces trajectoires

Multiple model particle filter

Dans cet article, on s'intéresse au problème du filtrage pour les systèmes à modèles dynamiques multiples appliqué à la poursuite de cible manoeuvrante. On choisit l'approche "particulaire" (type Monte Carlo), récemment proposée pour les problèmes de filtrage, car elle permet d'approcher, de manière non paramétrique et indépendante de la dimension la loi conditionnelle de l'état sachant les mesures, même dans les cas non linéaires ou non gaussiens. Le nouveau type de filtre particulaire, présenté ici, (Multiple Model Particle Filter, MMPF) est validé par son bon comportement lors des simulations

Translocation of particles and inflammatory responses after exposure to fine particles and nanoparticles in an epithelial airway model

ABSTRACT: BACKGROUND: Experimental studies provide evidence that inhaled nanoparticles may translocate over the airspace epithelium and cause increased cellular inflammation. Little is known, however, about the dependence of particle size or material on translocation characteristics, inflammatory response and intracellular localization. RESULTS: Using a triple cell co-culture model of the human airway wall composed of epithelial cells, macrophages and dendritic cells we quantified the entering of fine (1 mum) and nano-sized (0.078 mum) polystyrene particles by laser scanning microscopy. The number distribution of particles within the cell types was significantly different between fine and nano-sized particles suggesting different translocation characteristics. Analysis of the intracellular localization of gold (0.025 mum) and titanium dioxide (0.02-0.03 mum) nanoparticles by energy filtering transmission electron microscopy showed differences in intracellular localization depending on particle composition. Titanium dioxide nanoparticles were detected as single particles without membranes as well as in membrane-bound agglomerations. Gold nanoparticles were found inside the cells as free particles only. The potential of the different particle types (different sizes and different materials) to induce a cellular response was determined by measurements of the tumour necrosis factor-alpha in the supernatants. We measured a 2-3 fold increase of tumour necrosis factor-alpha in the supernatants after applying 1 mum polystyrene particles, gold nanoparticles, but not with polystyrene and titanium dioxide nanoparticles. CONCLUSION: Quantitative laser scanning microscopy provided evidence that the translocation and entering characteristics of particles are size-dependent. Energy filtering transmission electron microscopy showed that the intracellular localization of nanoparticles depends on the particle material. Both particle size and material affect the cellular responses to particle exposure as measured by the generation of tumour necrosis factor-alpha

Adaptive Approximate Bayesian Computational Particle Filters for Underwater Terrain Aided Navigation

International audienceTo perform long-term and long-range missions, underwater vehicles need reliable navigation algorithms. This paper considers multi-beam Terrain Aided Navigation which can provide a drift-free navigation tool. This leads to an estimation problem with implicit observation equation and unknown likelihood. Indeed, the measurement sensor is considered to be a numerical black box model that introduces some unknown stochastic noise. We introduce a measurement updating procedure based on an adaptive kernel derived from Approximate Bayesian Computational filters. The proposed method is based on two well-known particle filters: Regularized Particle Filter and Rao-Blackwellized Particle Filter. Numerical results are presented and the robustness is demonstrated with respect to the original filters, yielding to twice as less non-convergence cases. The proposed method increases the robustness of particle-like filters while remaining computationally efficient

ANALISIS FAKTOR – FAKTOR YANG MEMPENGARUHI KESUKSESAN WANITA PENGUSAHA PEMILIK EMERALD DANCER SEMARANG

Penelitian ini bertujuan untuk mengetahui faktor apa saja yang mempengaruhi kesuksesan wanita pengusaha pemilik Emerald Dancer Semarang. Persepsi tersebut didasarkan kepada teori faktor – faktor kesuksesan wanita pengusaha menurut Lee & Stearns, diantaranya adalah dukungan keluarga dan pengetahuan, ketrampilan komunikasi dan pengetahuan tentang bisnis, kompetensi produk dan kemampuan bisnis, dan ketersediaan sumber daya. Penelitian dilakukan dengan melakukan wawancara dengan memberikan pertanyaan berdasarkan indikator – indikator dari setiap variabel dan disebarkan kepada empat responden, yang terdiri dari wanita pengusaha pemilik Emerald Dancer Semarang, suami wanita pengusaha, dan dua vendor yang pernah bekerjasama dengan Emerald Dancer Semarang, yaitu Colorful Event Organizer dan Venus Videography. Kesimpulan dari penelitian faktor kesuksesan wanita pengusaha ini menyatakan bahwa keempat faktor kesuksesan wanita pengusaha menurut teori Lee & Stearns ini mampu mendorong wanita pengusaha pemilik Emerald Dancer dalam mencapai keberhasilan usahanya. Berdasarkan persepsi yang ada, maka peneliti memberikan beberapa saran agar Emerald Dancer Semarang dapat semakin berkembang dalam mencapai keberhasilan usahanya. Kata kunci : Dukungan keluarga dan pengetahuan, ketrampilan komunikasi dan pengetahuan tentang bisnis, kompetensi produk dan kemampuan bisnis, ketersediaan sumber daya

Navigation à l'aide d'un gravimètre atomique

International audienceCold atom interferometer is a promising technology to obtain a highly sensitive and accurate absolute gravimeter. With the help of an anomalies gravity map, local measurements of gravity allow a terrain-based navigation. This paper follows the one we published in Fusion 2017. Based on an atomic gravimeter we present a method to map the gravity anomaly. We propose a modification of the Laplace-based particle filter so as to make it more robust. Some simulation results demonstrate a better robustness of the proposed filter.L'interférométrie à atomes froids est une technologie prometteuse pour obtenir un gravimètre absolu de grande sensibilité et précision. A partir d'une carte d'anomalies gravimétriques, la mesure locale de la gravité permet une navigation par corrélation de terrain. Ce papier fait suite à celui publié au congrès Fusion 2017. Nous présentons une méthode d'élaboration de cartes d’anomalies gravimétriques à partir du gravimètre atomique. Nous proposons une modification du filtre Particulaire de Laplace qui offre une meilleure robustesse. Des résultats de simulation montrent une meilleure robustesse de ce filtre

Adaptive Approximate Bayesian Computational Particle Filters for Underwater Terrain Aided Navigation

International audienceTo perform long-term and long-range missions, underwater vehicles need reliable navigation algorithms. This paper considers multi-beam Terrain Aided Navigation which can provide a drift-free navigation tool. This leads to an estimation problem with implicit observation equation and unknown likelihood. Indeed, the measurement sensor is considered to be a numerical black box model that introduces some unknown stochastic noise. We introduce a measurement updating procedure based on an adaptive kernel derived from Approximate Bayesian Computational filters. The proposed method is based on two well-known particle filters: Regularized Particle Filter and Rao-Blackwellized Particle Filter. Numerical results are presented and the robustness is demonstrated with respect to the original filters, yielding to twice as less non-convergence cases. The proposed method increases the robustness of particle-like filters while remaining computationally efficient

Optimizing dialysis dose in the context of frailty: an exploratory study

Introduction Frailty is a multicausal syndrome characterized by a decrease in strength, resistance and physiological function, which makes the individual vulnerable and dependent, and increases his/her mortality. This syndrome is more prevalent among older individuals, and chronic kidney disease patients, particularly those on dialysis. Dialysis dose is currently standardized for hemodialysis (HD) patients regardless of their age and functional status. However, it has been postulated that the dialysis dose required in older patients, especially frail ones, should be lower, since it could increase their degree of frailty. Then, the purpose of this study was to evaluate if there would be a correlation between the dose of Kt/V and the degree of frailty in a population of adult patients on HD. Materials and methods A cross-sectional study with 82 patients on HD in Barranquilla (Colombia) and Lobos (Argentina) was conducted. Socio-demographic and laboratory data, as well as dialysis doses (Kt/V) were recorded and scales of fragility, physical activity, gait and grip strength were applied. Then these data were correlated by a Spearman’s correlation and a logistic regression. Results CFS, social isolation, physical activity, gait speed, and prehensile strength tests were outside the reference ranges in the studied group. No significant correlation was found between dialysis dose and all the above mentioned functional tests. However, a significant and inverse correlation between physical activity and CFS was documented (score − 1.41 (CI − 2.1 to − 0.7). Conclusion No significant correlation was documented between Kt/V value and different parameters of the frailty status, but this status correlated significantly and inversely with physical activity in this group. Frailty status in hemodialysis patients was significantly higher in older individuals, although young individuals were not exempt from it

Diagrammatic approach to non-Gaussianity from inflation

We present Feynman type diagrams for calculating the n-point function of the primordial curvature perturbation in terms of scalar field perturbations during inflation. The diagrams can be used to evaluate the corresponding terms in the n-point function at tree level or any required loop level. Rules are presented for drawing the diagrams and writing down the corresponding terms in real space and Fourier space. We show that vertices can be renormalised to automatically account for diagrams with dressed vertices. We apply these rules to calculate the primordial power spectrum up to two loops, the bispectrum including loop corrections, and the trispectrum.Comment: 17 pages, 13 figures. v2: Comments and references added, v3: Introduction expanded, subsection on evaluating loop diagrams added, minor errors corrected, references adde

Associative Vocabulary Learning: Development and Testing of Two Paradigms for the (Re-) Acquisition of Action- and Object-Related Words

Despite a growing number of studies, the neurophysiology of adult vocabulary acquisition is still poorly understood. One reason is that paradigms that can easily be combined with neuroscientfic methods are rare. Here, we tested the efficiency of two paradigms for vocabulary (re-) acquisition, and compared the learning of novel words for actions and objects. Cortical networks involved in adult native-language word processing are widespread, with differences postulated between words for objects and actions. Words and what they stand for are supposed to be grounded in perceptual and sensorimotor brain circuits depending on their meaning. If there are specific brain representations for different word categories, we hypothesized behavioural differences in the learning of action-related and object-related words. Paradigm A, with the learning of novel words for body-related actions spread out over a number of days, revealed fast learning of these new action words, and stable retention up to 4 weeks after training. The single-session Paradigm B employed objects and actions. Performance during acquisition did not differ between action-related and object-related words (time*word category: p = 0.01), but the translation rate was clearly better for object-related (79%) than for action-related words (53%, p = 0.002). Both paradigms yielded robust associative learning of novel action-related words, as previously demonstrated for object-related words. Translation success differed for action- and object-related words, which may indicate different neural mechanisms. The paradigms tested here are well suited to investigate such differences with neuroscientific means. Given the stable retention and minimal requirements for conscious effort, these learning paradigms are promising for vocabulary re-learning in brain-lesioned people. In combination with neuroimaging, neuro-stimulation or pharmacological intervention, they may well advance the understanding of language learning to optimize therapeutic strategies