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showing 10 items of 4384 documents
Voie et installations antiques en rive gauche de l'Armançon : Perrigny-sur-Armançon, Les Grands Prés : rapport de diagnostic
2010
L’extrémité nord du terrain livre des installations d’époque romaine polarisées autour de la voie romaine Dijon-Alésia-Sens. On note la présence de murs construits de part et d’autre du tracé. L’espace compris entre la chaussée et les murs est laissé globalement libre à l’exception de la présence de quelques structures ponctuelles (trous de poteau, fosses). La voie en elle-même, large de 6 m, est construite selon le mode classique : statumen, rudus et summum dorsum. Elle domine de plus de 1,20 m la plaine environnante.Détail d’importance, elle est à cet endroit coupée par deux murets qui pourraient constituer les limites est et ouest d’un petit canal. Cet espace est comblé par une sédimenta…
A detailed study of the rise phase of a long duration X-ray flare in the young star TWA 11B
2010
We analyzed a long duration flare observed in a serendipitous XMM-Newton detection of the M star CD-39 7717B (TWA 11B), member of the young stellar association TW Hya (~ 8 Myr). Only the rise phase (with a duration of ~ 35 ks) and possibly the flare peak were observed. We took advantage of the high count-rate of the X-ray source to carry out a detailed analysis of its spectrum during the whole exposure. After a careful analysis, we interpreted the rise phase as resulting from the ignition of a first group of loops (event A) which triggered a subsequent two-ribbon flare (event B). Event A was analyzed using a single-loop model, while a two-ribbon model was applied for event B. Loop semi-leng…
New view of the corona of classical T Tauri stars: Effects of flaring activity in circumstellar disks
2019
Classical T Tauri stars (CTTSs) are young low-mass stellar objects accreting mass from their circumstellar disks. They are characterized by high levels of coronal activity as revealed by X-ray observations. This activity may affect the disk stability and the circumstellar environment. Here we investigate if an intense coronal activity due to flares occurring close to the accretion disk may perturb the inner disk stability, disrupt the inner part of the disk and, possibly, trigger accretion phenomena with rates comparable with those observed. We model a magnetized protostar surrounded by an accretion disk through 3D magnetohydrodinamic simulations. We explore cases characterized by a dipole …
Exact constants in Poincaré type inequalities for functions with zero mean boundary traces
2014
In this paper, we investigate Poincare type inequalities for the functions having zero mean value on the whole boundary of a Lipschitz domain or on a measurable part of the boundary. We find exact and easily computable constants in these inequalities for some basic domains (rectangles, cubes, and right triangles) and discuss applications of the inequalities to quantitative analysis of partial differential equations. Copyright © 2014 John Wiley & Sons, Ltd.
Typologie du zircon des bentonites du Frasnien (carrière du Lion, Belgique) : utilité avant la datation U-Pb.
2006
5 pages; National audience
Périurbanisation, ségrégation sociale et accès aux services publics
2008
L'objectif de ce rapport est, d'une part, de mesurer la ségrégation à l'échelle des aires urbaines françaises et de tester l'hypothèse selon laquelle le mouvement de périurbanisation, touchant plus particulièrement les familles de classes moyennes, entraîne une bipolarisation accrue dans les pôles urbains, et, d'autre part, d'évaluer dans quelles mesures l'offre de services publics suivant les mouvements de populations renforce la ségrégation en y ajoutant une dimension supplémentaire en termes d'accessibilité à ceux-ci. Nous avons ainsi pu montrer qu'effectivement la périurbanisation de certaines catégories sociales, les catégories intermédiaires en 1990 et les cadres en 1999, tend à renfo…
Toward a virtual reconstruction of an antique three-dimensional marble puzzle
2017
International audience; Abstract | Introduction | Related Work | Acquisition Setup, Proposed Prototype: Calibration and Visibility | Preprocessing of Scanned Three-Dimensional Fragment Data | Processing of Scanned Three-Dimensional Surface Data: Matching | Conclusion and Future Works | Appendices | Acknowledgments | ReferencesAbstract. The reconstruction of broken objects is an important field of research for many applications, such as art restoration, surgery, forensics, and solving puzzles. In archaeology, the reconstruction of broken artifacts is a very time-consuming task due to the handling of fractured objects, which are generally fragile. However, it can now be supported by three-dim…
Adaptive Learning Process for the Evolution of Ontology-Described Classification Model in Big Data Context
2016
International audience; One of the biggest challenges in Big Data is to exploit value from large volumes of variable and changing data. For this, one must focus on analyzing the data in these Big Data sources and classify the data items according to a domain model (e.g. an ontology). To automatically classify unstructured text documents according to an ontology, a hierarchical multi-label classification process called Semantic HMC was proposed. This process uses ontologies to describe the classification model. To prevent cold start and user overload, the classification process automatically learns the ontology-described classification model from a very large set of unstructured text documen…
Dispositif virtuel d'aide à la chirurgie de l'épaule
2008
The goal of this research is to design a virtual reality prototype to assit an orthopedic surgeon during the replacement of the glenohumeral joint by prosthesis. This system aims to optimize the movements of prosthesized shoulder joint from a choice of various scenarios of pose. These works encompasses several topics such as : orthopedic surgery, image analysis, computer graphics and virtual reality. The chosen process includes a phase of modelling of the bony part of the articulation by simple geometric forms, this model is parameterized from radios or CT scans ; a phase of simulation of the movements of healthy glenohumeral joint ; nally the phase of simulation of cutting and drilling wit…
Semantic aware RSS query algebra
2010
International audience; Existing XML query algebras are not fully appropriate to retrieve RSS news items mainly due to three reasons: 1) RSS is text rich and its content is dependent on the wording and verbification of the author, thus semantic aware operators are needed; 2) news items are dynamic and consequently time oriented retrieval is needed; 3) a news item may evolve through time, or overlap with other news items and hence identifying relationships between items is also needed. In this paper, we aim to solve these issues by providing a dedicated RSS algebra based on semantic-aware operators that consider RSS characteristics. The provided operators are application domain specific and …