Spectral mixture analysis of EELS spectrum-images

Recent advances in detectors and computer science have enabled the acquisition and the processing of multidimensional datasets, in particular in the field of spectral imaging. Benefiting from these new developments, earth scientists try to recover the reflectance spectra of macroscopic materials (e.g., water, grass, mineral types...) present in an observed scene and to estimate their respective proportions in each mixed pixel of the acquired image. This task is usually referred to as spectral mixture analysis or spectral unmixing (SU). SU aims at decomposing the measured pixel spectrum into a collection of constituent spectra, called endmembers, and a set of corresponding fractions (abundances) that indicate the proportion of each endmember present in the pixel. Similarly, when processing spectrum-images, microscopists usually try to map elemental, physical and chemical state information of a given material. This paper reports how a SU algorithm dedicated to remote sensing hyperspectral images can be successfully applied to analyze spectrum-image resulting from electron energy-loss spectroscopy (EELS). SU generally overcomes standard limitations inherent to other multivariate statistical analysis methods, such as principal component analysis (PCA) or independent component analysis (ICA), that have been previously used to analyze EELS maps. Indeed, ICA and PCA may perform poorly for linear spectral mixture analysis due to the strong dependence between the abundances of the different materials. One example is presented here to demonstrate the potential of this technique for EELS analysis.Comment: Manuscript accepted for publication in Ultramicroscop

Auctioning airport slots (?)

The current allocation of slots on congested European airports constitutes an obstacle to the effective liberalisation of air transportation undertaken in Europe. With a view to favouring efficient slot utilisation and competition, as is the goal of the European commission, we propose to use a market mechanism, based on temporary utilisation licences. In order to allocate those licences, we propose and describe an iterated combinatorial auction mechanism where a percentage of licences would be reallocated each season. A secondary market would also be set up in order to reallocate slots during a season. Since a combinatorial auction involve a complex optimisation procedure, we describe how it can be made to work in the case of auctions.slots; airports; licence; auction; combinatorial

Une bonne recette de mortier pour les travaux de la tour de Montalquier (Gap, la Tourronde)

National audienceEtude d'une recette de mortier élaborée pour les réparations de la tour de Montalquier en 1384, d'après les comptes inédits de la châtellenie (AD38, 8 B 655)

A surprising relation between double exchange and Heisenberg model spectra: Application to half-doped manganites

The Zener polarons recently found in half-doped manganites are usually seen as mixed valence entities ruled by a double exchange Hamiltonian involving only correlated electrons of the metals. They can however be considered as ferrimagnetic local units if the holes are localized on the bridging oxygen atoms as implicitely suggested by recent mean-field it ab initio calculations. In the latter case, the physics is ruled by a Heisenberg Hamiltonian involving magnetic oxygen bridges. This paper shows that the spectra resulting from the resolution of both models are analytically identical. This single resulting model spectrum accurately reproduces the spectrum of Zener polarons in Pr0.6Ca0.4MnO3 manganite studied by means of explicitely correlated ab initio calculations. Since the physics supported by each model are different, the analysis of the exact Hamiltonian ground state wave function should a priori enables one to determine the most appropriate model. It will be shown that neither the spectrum nor the wavefunction analysis bring any decisive arguments to settle the question. Such undecidability would probably be encountered in experimental information.Comment: 4 pages, 2 figure

MobileR : Multi-hop energy efficient localised mobile georouting in wireless sensor and actuator networks

International audienceThis paper addresses the usage of actuators (sensors with controlled mobility) for routing in wireless sensor and actuator networks. Different routing protocols have been proposed to improve routing in terms of energy efficiency through the use of controlled mobility enabled sensors . We introduce MobileR. Unlike literature proposals also using actuators, MobileR considers the cost of a full path toward one of its neighbours instead of the cost of the direct edge toward it. To do so, MobileR computes in advance the possible routing paths over the next hops relying on the one-hop neighbours and their possible relocations. Moreover MobileR is fully localised and stateless. We evaluate our solution in terms of cumulative energy consumption with regard to network density. Experiments show that, with sufficient node degree, energy used for routing is significantly reduced and so network lifetime is extended

Domino Snake Problems on Groups

In this article we study domino snake problems on finitely generated groups. We provide general properties of these problems and introduce new tools for their study. The first is the use of symbolic dynamics to understand the set of all possible snakes. Using this approach we solve many variations of the infinite snake problem including the geodesic snake problem for certain classes of groups. Next, we introduce a notion of embedding that allows us to reduce the decidability of snake problems from one group to another. This notion enable us to establish the undecidability of the infinite snake and ouroboros problems on nilpotent groups for any generating set, given that we add a well-chosen element. Finally, we make use of monadic second order logic to prove that domino snake problems are decidable on virtually free groups for all generating sets.Comment: Accepted to FCT 2023. Comments welcome

Metz – 5 rue des Trinitaires

Les sondages réalisés dans l’immeuble situé 5 rue des Trinitaires, dans le quartier du Haut de Sainte-Croix, ont révélé les vestiges d’élévations médiévales remaniées au cours de la période moderne et jusqu’à nos jours. Dans ce bâtiment d’une surface au sol de 118 m2 au plan rectangulaire régulier, se développant sur six niveaux, seuls le rez-de-chaussée, les premier et troisième étages ont été sondés. La cave, de même surface que le rez-de-chaussée, est voûtée de deux voûtes en berceaux reto..

Metz – 12 rue Chèvremont

Le diagnostic prescrit 12 rue Chèvremont, en août 2016, a permis de mettre en évidence le volume initial d’une maison médiévale dans le quartier du Haut-de- Sainte-Croix. L’emprise de cette maison, dotée d’une cave en centre de parcelle, est clairement circonscrite au rez-de-chaussée par l’existence d’une façade postérieure qui ne présente pas de connexion avec le sous-sol mais qui s’est avérée conserver une arcade en pierre de taille. En parallèle de ce mur, à quelques 5 m au sud-est, une se..

Épinal – 11-13-15-17 rue Saint-Michel, parking (tranche 1), rue Saint-Michel

Un diagnostic du bâti, d’une superficie de 2 294 m2, a été prescrit à Épinal, à l’extrémité occidentale d’un vaste îlot trapézoïdal étiré le long de la rue Saint-Michel. La prescription porte sur la mise en évidence des vestiges de l’établissement des Hospitaliers de Saint-Jean-de-Jérusalem, situé extra muros, mentionné depuis 1194. L’angle sud-ouest de la nef d’une chapelle et une nécropole ont en effet été fouillés en 2000 (cf. Bilan scientifique régional Lorraine 2000, p. 122-123), en bord..