Search results for " Network"
showing 10 items of 6428 documents
A web application for event detection and exploratory data analysis for Twitter data
2015
International audience
Temporal Semantic Centrality for the Analysis of Communication Networks
2012
National audience; De nos jours, la compréhension des communautés en ligne devient un enjeu majeur du Web. Dans cet article nous proposons une nouvelle mesure, la Probabilité de Propagation Sémantique (SPP), qui caractérise la capacité de l'utilisateur à propager un concept sémantique à d'autres utilisateurs, d'une manière rapide et ciblée. La sémantique des messages est analysée selon une ontologie donnée. Nous utilisons cette mesure pour obtenir la Centralité Sémantique Temporelle (TSC) d'un utilisateur dans une communauté. Nous proposons et évaluons une expérimentation de cette mesure, en utilisant une ontologie et des données réelles issues du Web.
On Topological Structure of Web Services Networks for Composition. In Int. Journal of Web Engineering and Technology
2013
In order to deal efficiently with the exponential growth of the Web services landscape in composition life cycle activities, it is necessary to have a clear view of its main features. As for many situations where there is a lot of interacting entities, the complex networks paradigm is an appropriate approach to analyze the interactions between the multitudes of Web services. In this paper, we present and investigate the main interactions between semantic Web services models from the complex network perspective. Results show that both parameter and operation networks exhibit the main characteristics of typical real-world complex networks such as the "small-world" property and an inhomogeneou…
SIMILARITY NETWORK FOR SEMANTIC WEB SERVICES SUBSTITUTION
2013
Web services substitution is one of the most challenging tasks for automating the composition process of multiple Web services. It aims to improve performances and to deal efficiently with Web services failures. Many existing solutions have approached the problem through classification of substitutable Web services. To go a step further, we propose in this paper a network based approach where nodes are Web services operations and links join similar operations. Four similarity measures based on the comparison of input and output parameters values of Web services operations are presented. A comparative evaluation of the topological structure of the corresponding networks is performed on a ben…
High third and second order non linearities of chalcogenide glasses and fibers for compact infrared non linear devices.
2008
Due to their intrinsic nature, chalcogenide glasses present attractive nonlinearities from third and second order, with values reaching between 10 and 1000 times those of silica. We present a study of their properties and their shaping with the purpose to reach efficient devices in the near-mid infrared.
Near-field control of optical bistability in a nanocavity
2009
Micro- and nanocavities allow for strong light confinement in very small volume [1]. They give opportunities for new experiments such as cavity quantum electrodynamics, waveguiding, light slowing or trapping…[2] The increase of the electromagnetic (EM) field in the cavity enhances the interaction between light and matter, resulting in the possible observation of nonlinear effects [3]. Several studies have recently been published on the observation and characterisation of nonlinear silicon cavities [4]. As a step further, we propose and demonstrate the feasibility of an innovative way to mechanically control the bistable operating regime of a nanovavity. Using a near-field tip, we switch the…
Nonlinear Sculpturing of Optical Pulses in Fibre Systems
2019
The interplay among the effects of dispersion, nonlinearity and gain/loss in optical fibre systems can be efficiently used to shape the pulses and manipulate and control the light dynamics and, hence, lead to different pulse-shaping regimes [1,2]. However, achieving a precise waveform with various prescribed characteristics is a complex issue that requires careful choice of the initial pulse conditions and system parameters. The general problem of optimisation towards a target operational regime in a complex multi-parameter space can be intelligently addressed by implementing machine-learning strategies. In this paper, we discuss a novel approach to the characterisation and optimisation of …
A multispecies approach for modeling the ecological impact of urban development using landscape graphs
2013
International audience; Managing urban sprawl is become a major concern in the field of landscape ecology, since the land use changes involved by urban development may affect the ability of wildlife species to move across the landscape. In order to compare the ecological impact of several urban patterns, we aim at combining two complementary approaches: 1) Simulations of residential development from an initial land use map, using morphological rules of urban development (i.e. fractal vs non fractal) and accessibility constraints; 2) Models of ecological networks applied to a given natural habitat, using a landscape graphs-based approach. As landscape graphs are built according to the moving…
Graphab: A software dedicated to the modelling of landscape networks
2016
International audience; Land cover changes resulting from urban sprawl, transport network intensification and agricultural changes contribute to fragment wildlife habitats and may lead to question viability of animal and plant populations. Landscape ecologists have shown that populations living in fragmented habitats are forced to adopt specific dynamics (patchy populations or metapopulations) making them highly dependent on fluxes between their habitat patches. Landscape connectivity may be defined as the functional response of a given species in terms of movement and individual fluxes to the potential links between habitat patches provided by the landscape structure.Many methods are used …
Networks of Seed Storage Protein Regulation in Cereals and Legumes at the Dawn of the Omics Era
2012
BAP GEAPSI CT2 (BAP); International audience; Finely regulated and orchestrated events occur during seed development and germination in different cell organelles (mitochondria, peroxisomes, plastids, vacuoles, endoplasmic reticulum, oil bodies and nuclei). Therefore, some of the ongoing investigations pass through sub-cellular organelle purifications for a deeper comprehension of these complex developmental processes. In seed biology, recent ambitious efforts in proteomics have been directed toward organelle isolation from seeds and high-throughput protein separation and identification by mass spectrometry at defined developmental stages. The construction of reference maps allowed identifyi…