On simple arrangements of lines and pseudo-lines in P^2 and R^2 with the maximum number of triangles

We give some new advances in the research of the maximum number of triangles that we may obtain in a simple arrangements of n lines or pseudo-lines.Comment: 12 pages, 9 figure

Constitutionnalisme et exclusion : critique du regard français sur le modèle canadien de pluralisme

La recherche vise à mettre en évidence les relations entre constitutionnalisme et exclusion dans le cadre d’unecritique du regard français sur le modèle canadien de pluralisme. La problématique de l’exclusion, être altériséen raison de l’identité du droit, naît des silences de la comparaison différentielle France – Canada. Une critiqueidentitaire permet de déplacer la triple dialectique de la comparaison : positivisme c. pluralisme, universalisme c.différentialisme et républicanisme c. libéralisme pluraliste. La problématique de l’orientation identitaire du droitest commune aux deux systèmes juridiques. Aussi, la recherche est relative à l’identité du constitutionnalisme.L’exclusion se définit comme le décalage entre l’orientation identitaire du constitutionnalisme et l’identité ducorps du sujet. La méthode d’analyse proposée, afin de traiter de l’exclusion en droit, et déplacer la comparaison,est tripartite : mettre en évidence l’orientation identitaire du constitutionnalisme, en identifier la structureidentitaire, pour, enfin, en déterminer les étrangers ou « Autres. » La recherche vise à déplacer la comparaison enproduisant une phénoménologie de l’exclusion constitutionnelle, ou « dehors constitutifs, » avec une typologiedes étrangers du droit. La démonstration sera faite dans le cadre des conflits de la religion et de l’orientationsexuelle démontrant l’orientation blanche, hétéropatriarcale et hétéronormative du droit constitutionnel.This research intends on proving how constitutionalism and exclusion collide one against the other trhough a critique of the french gaze on a supposedly canadian model of pluralism. This negative comparison's silencesbetween France and Canada gave birth to this question of how one is being excluded and othered based on the identity of constitutional law. This critique, that focuses on identities, is shifting those three dialectics supporting the aforementioned negative comparison: positivism v. pluralism; universalism v. differentialism; republicanism v. liberal pluralism. France and Canada share this issue of how reality is oriented towards specific identities. This research is, then, a critique of constitutional identities. Exclusion is defined as the gap between the orientation of law's identitiesnd the bodily reality of its subjects.The analytical tool developed here to tackle exclusionin law has three steps:shedding lighton the orientations of constitutionalism, its identity structure, and its constitutional Others.The research purports on turning shcolars' critical gazetowards this phenomenology of constitutional exclusion, its "constitutive outside," by deciphering a typologyof constitutional Others. Thiw will be through the collisions of freedom of religionand sexual orientation. Constitutionalism is per se oriented towardshe ascendency of whiteness, patriarcalism and heteronormativity

Etude péridynamique de la rupture de particules sous impact

La réduction en poudre des matériaux, ou comminution, est un procédé omniprésent dans divers secteurs industriels. La maîtrise de la distribution des tailles de particules est un enjeu déterminant pour garantir les qualités d'usage des produits. Dans cette étude on s'intéressera plus particulièrement à la modélisation numérique de la fragmentation de particules individuelles 2D soumises à des impacts à différentes énergies. La mécanique de la rupture de ces particules est étudiée à l'aide d'une approche péridynamique. La propagation des fissures est étudiée ainsi que l'appartion de fragments. Enfin, la statistique des tailles de fragments est obtenue sur une collection de particules broyées à partir d'une analyse d'images basée sur un algorithme de type floodfill

Orientational order of carbon nanotube guests in a nematic host suspension of colloidal viral rods

In order to investigate the coupling between the degrees of alignment of elongated particles in binary nematic dispersions, surfactant stabilized single-wall carbon nanotubes (CNTs) have been added to nematic suspensions of colloidal rodlike viruses in aqueous solution.We have independently measured the orientational order parameter of both components of the guest-host system by means of polarized Raman spectroscopy and by optical birefringence, respectively. Our system allows us therefore to probe the regime where the guest particles (CNTs) are shorter and thinner than the fd virus host particles. We show that the degree of order of the CNTs is systematically smaller than that of the fd virus particles for the whole nematic range. These measurements are in good agreement with predictions of an Onsager-type second-viral theory, which explicitly includes the flexibility of the virus particles, and the polydispersity of the CNTs.Comment: 5 pages, 2 figure

Fractal properties of the frontier in Poissonian coloring

We study a model of random partitioning by nearest-neighbor coloring from Poisson rain, introduced independently by Aldous and Preater. Given two initial points in $[0,1]^d$ respectively colored in red and blue, we let independent uniformly random points fall in $[0,1]^d$, and upon arrival, each point takes the color of the nearest point fallen so far. We prove that the colored regions converge in the Hausdorff sense towards two random closed subsets whose intersection, the frontier, has Hausdorff dimension strictly between $(d-1)$ and $d$, thus answering a conjecture raised by Aldous. However, several topological properties of the frontier remain elusive.Comment: 21 pages, 8 figures. Comments welcome

Crowdsourcing the georeferencing of historical pictures

Countless organizations own archive pictures which are not used due to the difficulty of localizing them. Only the participation of volunteers can help to identify the image content. Through an accessible web interface called smapshot, citizens are able to georeference historical images without any prior specific competence. To avoid the volunteers to face the complexity of 3D digitization and navigation, we implemented a state of the art photogrammetry camera orientation algorithm in the platform. Currently several thousand images from all around Switzerland have been georeferenced by the crowd. At this time the tool is mainly used by the population for the visualization experience and the nostalgia behind it. The ambition is to support scientists to analyze landscape evolution

Artificial Gene Regulatory Network and Spatial Computation: A Case Study

International audienceThis paper explores temporal and spatial dynamics of a population of Genetic Regulatory Networks (GRN). In order to so, a GRN model is spatially distributed to solve a multi-cellular Artificial Embryogeny problem, and Evolutionary Computation is used to optimize the developmental sequences. An in-depth analysis is provided and show that such a population of GRN display strong spatial synchronization as well as various kind of behavioral patterns, ranging from smooth diffusion to abrupt transition patterns

Artificial Gene Regulatory Networks and Spatial Computation: A Case Study

International audienceThis paper explores temporal and spatial dynamics of a population of Genetic Regulatory Networks (GRN). In order to so, a GRN model is spatially distributed to solve a multi-cellular Artificial Embryogeny problem, and Evolutionary Computation is used to optimize the developmental sequences. An in-depth analysis is provided and show that such a population of GRN display strong spatial synchronization as well as various kind of behavioral patterns, ranging from smooth diffusion to abrupt transition patterns