2,926 research outputs found

    P ORTOLAN: a Model-Driven Cartography Framework

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    Processing large amounts of data to extract useful information is an essential task within companies. To help in this task, visualization techniques have been commonly used due to their capacity to present data in synthesized views, easier to understand and manage. However, achieving the right visualization display for a data set is a complex cartography process that involves several transformation steps to adapt the (domain) data to the (visualization) data format expected by visualization tools. To maximize the benefits of visualization we propose Portolan, a generic model-driven cartography framework that facilitates the discovery of the data to visualize, the specification of view definitions for that data and the transformations to bridge the gap with the visualization tools. Our approach has been implemented on top of the Eclipse EMF modeling framework and validated on three different use cases

    Efficient Operations On MDDs For Building Constraint Programming Models

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    International audienceWe propose improved algorithms for defining the most common operations on Multi-Valued Decision Diagrams (MDDs): creation, reduction, complement , intersection, union, difference, symmetric difference, complement of union and complement of intersection. Then, we show that with these algorithms and thanks to the recent development of an efficient algorithm establishing arc consistency for MDD based constraints (MDD4R), we can simply solve some problems by modeling them as a set of operations between MDDs. We apply our approach to the regular constraint and obtain competitive results with dedicated algorithms. We also experiment our technique on a large scale problem: the phrase generation problem and we show that our approach gives equivalent results to those of a specific algorithm computing a complex automaton

    Enhanced Inter-Cell Interference Coordination Challenges in Heterogeneous Networks

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    3GPP LTE-Advanced has started a new study item to investigate Heterogeneous Network (HetNet) deployments as a cost effective way to deal with the unrelenting traffic demand. HetNets consist of a mix of macrocells, remote radio heads, and low-power nodes such as picocells, femtocells, and relays. Leveraging network topology, increasing the proximity between the access network and the end-users, has the potential to provide the next significant performance leap in wireless networks, improving spatial spectrum reuse and enhancing indoor coverage. Nevertheless, deployment of a large number of small cells overlaying the macrocells is not without new technical challenges. In this article, we present the concept of heterogeneous networks and also describe the major technical challenges associated with such network architecture. We focus in particular on the standardization activities within the 3GPP related to enhanced inter-cell interference coordination.Comment: 12 pages, 4 figures, 2 table

    Topological modes in stellar oscillations

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    Stellar oscillations can be of topological origin. We reveal this deep and so-far hidden property of stars by establishing a novel parallel between stars and topological insulators. We construct an hermitian problem to derive the expression of the stellar acoustic-buoyant\mathrm{\textit{acoustic-buoyant}} frequency SS of non-radial adiabatic pulsations. A topological analysis then connects the changes of sign of the acoustic-buoyant frequency to the existence of Lamb-like waves within the star. These topological modes cross the frequency gap and behave as gravity modes at low harmonic degree \ell and as pressure modes at high \ell. SS is found to change sign at least once in the bulk of most stellar objects, making topological modes ubiquitous across the Hertzsprung-Russel diagram. Some topological modes are also expected to be trapped in regions where the internal structure varies strongly locally.Comment: 6 pages, 5 figures (+7 pages, 3 figures of appendices

    Validación lingüística y psicométrica (adaptación cultural) de la escala Plutss para disfunción del tracto urinario inferior en niños colombianos

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    80% de los niños con ITU recurrente tiene algún síntoma de disfunción del tracto urinario inferior. Estos síntomas se clasifican según la ICCS (International Childrens Continence Society) de acuerdo a la fase del funcionamiento de la vejiga en la que presenten alteración, están los síntomas de llenado, los de eliminación y los asociados. Caracterizar estos síntomas, en forma objetiva para que no fueran simples relatos descriptivos de quejas de pacientes y pudieran ser utilizados para hacer diagnóstico y monitorear tratamiento obligó al uso de escalas que puntuaran cada uno de ellos. Estas escalas tienen su origen en el concepto del I-PSS (Puntaje Internacional de los Síntomas Prostáticos) que es una herramienta de gran utilidad para la clasificación de la hipertrofia prostática Hoy en día hay tres herramientas validadas para evaluar las alteraciones del tracto urinario inferior en niños; sin embargo ninguna de ellas ha sido a sido traducida al español ni adaptada culturalmente a la población hispanoamericana. El objetivo de este estudio es realizar la adaptación cultural (validación lingüística y psicométrica) de la escala PLUTSS,(4) que ya esta validada y es ampliamente utilizada; para aplicarla en un grupo de niños Colombianos estableciendo así el comportamiento de estos síntomas en nuestra población y para que pueda ser utilizada como herramienta de diagnóstico y seguimiento en los niños con alteración del tracto urinario inferior80% of children with recurrent urinary infection have any symptoms of lower urinary tract dysfunction. To characterize these symptoms, objectively forced the use of scales to rate each of them. Today there are three validated tools to assess the lower urinary tract disorders in children, but none has been been translated into Spanish and culturally adapted to the Hispanic American population. The aim of this study is to adapt the scale PLUTSS cultural, which is proven and widely used, to apply in a group of Colombian children, thus establishing the behavior of these symptoms. METHODOLOGY: The scale PLUTSS (Pediatric Symptom Score Lower Urinary Tract) was translated into Spanish adapted to Colombian dialect according to the admissions standards of translation, synthesis, back translation and recommendation of experts, was applied to a group of 34 patients with clinical diagnosis of urinary tract disorder lower and 95 healthy controls. Validation was conducted appearance, construct validation, we assessed the internal consistency of the instrument, and compared with results obtained in the original scale. RESULTS: The median of the two groups (healthy and diseased) was significantly different, with a sensitivity and specificity of 90% cut off point 1.5. Internal consistency of the 13-item scale was high alpha Crobanch, (0.88). Established the criterion validity of the scale with the clinical diagnosis found a significant correlation of strong character (CONCLUSIONS: The scale linguistic and psychometrically validated PLUTSS under international standards validation of scales is the only scale adapted Spanish. showed a high correlation with the clinical diagnosis and high power to discriminate urinary symptoms

    The Exceptional Ring of buoyancy instability in stars

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    We reveal properties of global modes of linear buoyancy instability in stars, characterised by the celebrated Schwarzschild criterion, using non-Hermitian topology. We identify a ring of Exceptional Points of order 4 that originates from the pseudo-Hermitian and pseudo-chiral symmetries of the system. The ring results from the merging of a dipole of degeneracy points in the Hermitian stablystratified counterpart of the problem. Its existence is related to spherically symmetric unstable modes. We obtain the conditions for which convection grows over such radial modes. Those are met at early stages of low-mass stars formation. We finally show that a topological wave is robust to the presence of convective regions by reporting the presence of a mode transiting between the wavebands in the non-Hermitian problem, strengthening their relevance for asteroseismology.Comment: 5 pages, 4 figures, + appendices, accepted for publication in Physical Review Researc

    Grid coevolution for adaptive simulations; application to the building of opening books in the game of Go

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    International audienceThis paper presents a successful application of parallel (grid) coevolution applied to the building of an opening book (OB) in 9x9 Go. Known sayings around the game of Go are refound by the algorithm, and the resulting program was also able to credibly comment openings in professional games of 9x9 Go. Interestingly, beyond the application to the game of Go, our algorithm can be seen as a ”meta”-level for the UCT-algorithm: ”UCT applied to UCT” (instead of ”UCT applied to a random player” as usual), in order to build an OB. It is generic and could be applied as well for analyzing a given situation of a Markov Decision Process
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