Search results for "visualisation"
showing 10 items of 50 documents
Intelligence stratégique et dissimulation dans les outils de géovisualisation en ligne
2014
Interactive geovisualization portals, set up on the Internet after the iconic Google Maps, are highly regarded by the public. They provide the ability to see from above the surface of our planet, and more specifically the French territory in the case of Geoportail. Yet it is forbidden to approach too close to certain objects: on national territory, some 150 sites are in fact hidden by the IGN. This paper question the relevance and efficiency of this operation imposed on the main body of production and dissemination of spatial information in France, in comparison with the means used by other countries.
Query expansion and semantic visualization in information system cooperations : methods and tools for information retrieval
2010
This thesis presents approaches and tools for information retrieval. Our work is part of a cooperation system based on ontologies called OWSCIS (Ontology and Web Service based Cooperation of Information Sources). We treat the problem of information retrieval by providing an enrichment method called QUEXME (QUery EXpansion MEthod) of queries based on analysis of user behavior and using the concept importance notion with regards to query. We also discussed the problem of visualization in the OWSCIS system offering a architecture of service visualization. It is composed of three modules: the request, enrichment and results. The approaches proposed in this thesis have been prototyped and the te…
Visual understanding of divergence and curl: Visual cues promote better learning
2019
Prior research has shown that students struggle to indicate whether vector field plots have zero or non-zero curl or divergence. In an instruction-based eye-tracking study, we investigated whether visual cues (VC) provided in the vector field plot can foster students’ understanding of these concepts. The VC were only present during instruction and highlighted conceptual information about vector decomposition and partial derivatives. Thirty-two physics majors were assigned to two groups, one was instructed with VC about the problemsolving strategy, and one without. The results show that students in VC-condition performed better, responded with higher confidence, experienced less mental effor…
Modes de visualisation spécifiques de l'analyse de données lexicologiques
1984
International audience
Sélection de bandes pour la visualisation d'images spectrales : une approche basée sur l'étude de saillance
2011
National audience; De nos jours, la plupart des technologies d'affichage numériques sont basées sur le paradigme qu'une combinaison de trois couleurs primaires spécifiques est suffisante pour la reproduction d'une couleur quelconque pour l'oeil humain. Par ailleurs, les dispositifs d'affichage multispectraux ne sont pas encore monnaie courante sur le marché du multimédia. Ainsi, lorsqu'il s'agit de visualiser une image spectrale en couleur, sur un écran traditionnel, seuls trois bandes peuvent être utilisées simultanément, ce qui implique une réduction de dimensionnalité. Cette étape doit permettre la préservation d'un maximum de contenu informatif tout en préservant contrastes et couleurs …
Towards Advanced Visualisation Techniques in Case
1999
The complexity of information systems has resulted in more sophisticated CASE tools which integrate multifaceted design information using metamodeling and hypertext technologies. A designer can use this vast amount of tightly coupled information efficiently only if it is presented based on his needs and cognitive capabilities. In this paper we discuss how representations in CASE can be improved using advanced visualisation techniques.
Proposition méthodologique pour la visualisation et l'exploration des mobilités géographiques
2016
Daily mobility data are multidimensional and desaggregated, what make them hard to manipulate and to analyze. Although methods of representation and analyze have been proposed, none of them seem to be able to efficiently bring out knowledge from data. We propose to combinate this solutions and a methodology of innovative reaggregation to visualize and explore mobility data.
Performance optimisation of biological pathway data storage, retrieval, analysis and its interactive visualisation
2018
The aim of this research was to optimise the performance of the storage, retrieval, analysis and interactive visualisation of biomolecular pathways data. This was achieved by the adoption of new technologies and a variety of highly optimised data structures, algorithms and strategies across the different layers of the software. The first challenge to overcome was the creation of a long-lasting, large-scale web application to enable pathways navigation; the Pathway Browser. This tool had to aggregate different modules to allow users to browse pathway content and use their own data to perform pathway analysis. Another challenge was the development of a high-performance pathway analysis tool t…
Graphical Structure of Attraction Basins of Hidden Chaotic Attractors : The Rabinovich-Fabrikant System
2019
The attraction basin of hidden attractors does not intersect with small neighborhoods of any equilibrium point. To the best of our knowledge this property has not been explored using realtime interactive three-dimensions graphics. Aided by advanced computer graphic analysis, in this paper, we explore this characteristic of a particular nonlinear system with very rich and unusual dynamics, the Rabinovich–Fabrikant system. It is shown that there exists a neighborhood of one of the unstable equilibria within which the initial conditions do not lead to the considered hidden chaotic attractor, but to one of the stable equilibria or are divergent. The trajectories starting from any neighborhood o…
Study of drilling and welding laser : dynamics of keyhole
2011
The aim of the present work is to study experimentally the formation of the capillary during the drilling and welding by laser beam and to develop the numerical simulation which allows following the dynamics and the evolution of the keyhole. The zinc was chosen as a test material because its thermodynamical properties are well known. To simplify the problem, in the first place the drilling mechanism was studied. Two experimental methods were used to characterize the evolution of the keyhole: the Direct Observation of Drilled Hole method, which allows the visualization of the keyhole after the application of laser pulses of different durations, and Zn-Quartz method, which allows the direct o…