Pedestrian tracking in car parks: an Adaptive Interacting Multiple Model based Filtering Method

voir basilic : http://emotion.inrialpes.fr/bibemotion/2006/BASL06a/To address perception problems we must be able to track dynamics targets of the environment. An important issue of tracking is filtering problem in which estimates of the targets state are computed while observations are progressively received. This paper presents an adaptive Interacting Multiple Models (IMM) based filtering method. Interacting Multiple Models have been successfully applied to many applications as they allow, using several filters in parallel, to deal with the uncertainty on motion model, a critical component of filtering. Indeed targets can rapidly change their motion over a lapse of time. This is the case of pedestrians for which it is difficult to define an unique motion model which matches all their possible displacements. Nevertheless, the Transition Probability Matrix (TPM) which models the interaction between different filters in an IMM is in currently defined a priori or needs an important amount of tuning to be used efficiently. In this paper, we put forward a method which automatically adapts online the TPM. The TPM adaptation using on-line data significantly improves the effectiveness of IMM filtering and so better target estimates are obtained. To validate our work we applied our method to pedestrian tracking in car parks on a real platform

Adaptive Interactive Multiple Models applied on pedestrian tracking in car parks

voir basilic : http://emotion.inrialpes.fr/bibemotion/2006/BASL06/ address: Beijing (CN)To address perception problems we must be able to track dynamics targets of the environment. An important issue of tracking is filtering problem in which estimates of the targets state are computed while observations are progressively received. This paper presents an adaptive Interacting Multiple Models (IMM) based filtering method. Interacting Multiple Models have been successfully applied to many applications as they allow, using several filters in parallel, to deal with the uncertainty on motion model, a critical component of filtering. Indeed targets can rapidly change their motion over a lapse of time. This is the case of pedestrians for which it is difficult to define an unique motion model which matches all their possible displacements. Nevertheless, the Transition Probability Matrix (TPM) which models the interaction between different filters in an IMM is in currently defined a priori or needs an important amount of tuning to be used efficiently. In this paper, we put forward a method which automatically adapts online the TPM. The TPM adaptation using on-line data significantly improves the effectiveness of IMM filtering and so better target estimates are obtained. To validate our work we applied our method to pedestrian tracking in car parks on a real platform

Neutron scattering study of transverse magnetism

In order to clarify the nature of the additional phase transition at H1 (T) \u3c Hc (T) of the layered antiferromagnetic (AF) insulator FeBr2 as found by Aruga Katori et al. (1996) we measured the intensity of different Bragg-peaks in different scattering geometries. Transverse AF ordering is observed in both AF phases, AFI and AFII. Its order parameter exhibits a peak at T1 = T (H1) in temperature scans and does not vanish in zero field. Possible origins of the step-like increase of the transverse ferromagnetic ordering induced by a weak in-plane field component when entering AFI below T1 are discussed

Spring Water Geochemistry: A Geothermal Exploration Tool in the Rhenohercynian Fold-and-Thrust Belt in Belgium

peer reviewedSpring water geochemistry is applied here to evaluate the geothermal potential in Rhenohercynian fold and thrust belt around the deepest borehole in Belgium (Havelange borehole: 5648 m MD). Fifty springs and (few) wells around Havelange borehole were chosen according to a multicriteria approach including the hydrothermal source of “Chaudfontaine” (T ≈ 36 ◦C) taken as a reference for the area. The waters sampled, except Chaudfontaine present an in-situ T range of 3.66–14.04 ◦C (mean 9.83 ◦C) and a TDS (dry residue) salinity range of 46–498 mg/L. The processing methods applied to the results are: hierarchical clustering, Piper and Stiff diagrams, TIS, heat map, boxplots, and geothermometry. Seven clusters are found and allow us to define three main water types. The first type, locally called “pouhon”, is rich in Fe and Mn. The second type contains an interesting concentration of the geothermal indicators: Li, Sr, Rb. Chaudfontaine and Moressée (≈5 km East from the borehole) belong to this group. This last locality is identified as a geothermal target for further investigations. The third group represents superficial waters with frequently high NO3 concentration. The application of conventional geothermometers in this context indicates very different reservoir temperatures. The field of applications of these geothermometers need to be review in these geological conditions.MEE

Trace-element imaging at macroscopic scale in a Belgian sphalerite-galena ore using Laser-Induced Breakdown Spectroscopy (LIBS)

Laser-Induced Breakdown Spectroscopy (LIBS) is a fast in-situ analytical technique based on spectroscopic analysis of atomic emission in laser-induced plasmas. Geochemical mapping at macroscopic scale using LIBS was applied to a decimetric Zn-Pb ore sample from east Belgium, which consists of alternating sphalerite and galena bands. A range of elements was detected with no or minimal spectral correction, including elements of interest for beneficiation such as Ge, Ag and Ga (although the detection of gallium could not be confirmed), and remediation, especially As and Tl. The comparison between LIBS and Energy Dispersive Spectroscopy (EDS) analyses showed that LIBS intensities reliably relate to elemental concentration although differences in spot size and detection limits exist between both techniques. The elemental images of minor and trace elements (Fe, Cu, Ag, Cd, Sb, As, Tl, Ge, Ni and Ba) obtained with LIBS revealed with great detail the compositional heterogeneity of the ore, including growth zones that were not visible on the specimen. In addition, each mineral generation has a distinct trace-element composition, reflecting a geochemical sequence whose potential metallogenic significance at the district scale should be addressed in further work. Although qualitative and preliminary, the obtained LIBS dataset already produced a wealth of information that allowed to initiate discussion on some genetical and crystallochemical aspects. Above all, LIBS appears as a powerful tool for screening geochemically large samples for the selection of zones of particular interest for further analysis.LIBS Scree

First Early Hominin from Central Africa (Ishango, Democratic Republic of Congo)

Despite uncontested evidence for fossils belonging to the early hominin genus Australopithecus in East Africa from at least 4.2 million years ago (Ma), and from Chad by 3.5 Ma, thus far there has been no convincing evidence of Australopithecus, Paranthropus or early Homo from the western (Albertine) branch of the Rift Valley. Here we report the discovery of an isolated upper molar (#Ish25) from the Western Rift Valley site of Ishango in Central Africa in a derived context, overlying beds dated to between ca. 2.6 to 2.0 Ma. We used µCT imaging to compare its external and internal macro-morphology to upper molars of australopiths, and fossil and recent Homo. We show that the size and shape of the enamel-dentine junction (EDJ) surface discriminate between Plio-Pleistocene and post-Lower Pleistocene hominins, and that the Ishango molar clusters with australopiths and early Homo from East and southern Africa. A reassessment of the archaeological context of the specimen is consistent with the morphological evidence and suggest that early hominins were occupying this region by at least 2 Ma

Suivi multi-objets adaptatif ( application à la classification de comportements de mobiles )

Le thème central de cette thèse est celui de la perception robuste en environnement dynamique. Dans ce contexte, nous nous intéressons à réaliser de manière aussi robuste que possible, un suivi de plusieurs cibles en mouvement observées par des capteurs foumissant des données bruitées. Cette thèse se focalisés sur le développement d'une méthode de suivi multi-objets dans laquelle le filtrage est auto-adaptatif. Dans cette méthode, un prinèipe d'adaptation automatique est utilisé pour redéfinir en ligne le filtrage en fonction des trajectoires effectuées par les objets. Au final, une méthode efficace, robuste et adaptative permettant de pallier les changements de dynamique des objets est obtenue. Enfin, le principe automatique est utilisé pour classifier les comportements des objets, permettant de spécifier de façon plus robuste les prédictions sur les déplacements de ces derniers.The framework of this thesis is the robust perception in dynamic environment. ln this context, we are interested in achieving robust tracking of multiple moving targets observed by noisy sensors. This thesis is focused on developing a multiple-tracking method in which filtering is auto-adapted on-line. ln this method, a principle of automatic adjustment is used to redefine online filtering based on the obejects' paths. Furthermore, an effective method, robust and adaptive permitting to cope with dynamic changements of objects is obtained. Finally, the principle is used to automatically classify the behavior of objects, allowing to obtain more robust predictions on the objects' movement.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Adaptive Interactive Multiple Models applied on pedestrian tracking in car parks

voir basilic : http://emotion.inrialpes.fr/bibemotion/2006/BASL06/ address: Beijing (CN)To address perception problems we must be able to track dynamics targets of the environment. An important issue of tracking is filtering problem in which estimates of the targets state are computed while observations are progressively received. This paper presents an adaptive Interacting Multiple Models (IMM) based filtering method. Interacting Multiple Models have been successfully applied to many applications as they allow, using several filters in parallel, to deal with the uncertainty on motion model, a critical component of filtering. Indeed targets can rapidly change their motion over a lapse of time. This is the case of pedestrians for which it is difficult to define an unique motion model which matches all their possible displacements. Nevertheless, the Transition Probability Matrix (TPM) which models the interaction between different filters in an IMM is in currently defined a priori or needs an important amount of tuning to be used efficiently. In this paper, we put forward a method which automatically adapts online the TPM. The TPM adaptation using on-line data significantly improves the effectiveness of IMM filtering and so better target estimates are obtained. To validate our work we applied our method to pedestrian tracking in car parks on a real platform

Comparative analysis of transposable elements in the melanogaster subgroup sequenced genomes.

International audienceTransposable elements (TEs) are indwelling components of genomes, and their dynamics have been a driving force in genome evolution. Although we now have more information concerning their amounts and characteristics in various organisms, we still have little data from overall comparisons of their sequences in very closely-related species. While the Drosophila melanogaster genome has been extensively studied, we have only limited knowledge regarding the precise TE sequences in the genomes of the related species Drosophila simulans, Drosophila sechellia and Drosophila yakuba. In this study we analyzed the number and structure of TE copies in the sequenced genomes of these four species. Our findings show that, unexpectedly, the number of TE insertions in D. simulans is greater than that in D. melanogaster, but that most of the copies in D. simulans are degraded and in small fragments, as in D. sechellia and D. yakuba. This suggests that all three species were invaded by numerous TEs a long time ago, but have since regulated their activity, as the present TE copies are degraded, with very few full-length elements. In contrast, in D. melanogaster, a recent activation of TEs has resulted in a large number of almost-identical TE copies. We have detected variants of some TEs in D. simulans and D. sechellia, that are almost identical to the reference TE sequences in D. melanogaster, suggesting that D. melanogaster has recently been invaded by active TE variants from the other species. Our results indicate that the three species D. simulans, D. sechellia, and D. yakuba seem to be at a different stage of their TE life cycle when compared to D. melanogaster. Moreover, we show that D. melanogaster has been invaded by active TE variants for several TE families likely to come from D. simulans or the ancestor of D. simulans and D. sechellia. The numerous horizontal transfer events implied to explain these results could indicate introgression events between these species