Search results for " Computer science"
showing 10 items of 3983 documents
Reconstruction et analyse sémantique de chronologies cybercriminelles
2014
International audience; La reconstruction de scénarios est l’une des étapes les plus importantes d’une investigation numérique. Elle permet aux enquêteurs d’avoir une vue des évènements survenus durant un incident. La reconstruction de scénarios est une tâche complexe requérant l’étude d’un très grand nombre d’évènements en raison de l’omniprésence des nouvelles technologies dans notre quotidien. De plus, les conclusions produites se doivent de respecter les critères fixés par la justice. Afin de répondre à ces challenges, nous proposons une nouvelle méthodologie, basée sur une ontologie intégrant les connaissances d’experts des domaines de la criminalistique et de l’ingénierie logicielle, …
De la scène de crime aux connaissances : représentation d'évènements et peuplement d'ontologie appliqués au domaine de la criminalistique informatique
2015
International audience; Avec la démocratisation des technologies, les enquêtes de criminalistique informatique impliquent des volumes de données toujours plus grands et hétérogènes. Pour faciliter le travail des enquêteurs, nos travaux ont pour objectif de reconstruire automatiquement les évènements liés à un incident numérique, tout en respectant les exigences légales. Pour cela, il est nécessaire d'introduire un modèle de représentation de connaissances permettant de structurer les informations recueillies sur une scène de crime dans le but de faciliter l'utilisation de processus d'analyse automatisés. Ce papier propose un état de l'art des modèles de représentations d'évènements pour le …
Lossless and nearly-lossless image compression based on combinatorial transforms
2011
Common image compression standards are usually based on frequency transform such as Discrete Cosine Transform or Wavelets. We present a different approach for loss-less image compression, it is based on combinatorial transform. The main transform is Burrows Wheeler Transform (BWT) which tends to reorder symbols according to their following context. It becomes a promising compression approach based on contextmodelling. BWT was initially applied for text compression software such as BZIP2 ; nevertheless it has been recently applied to the image compression field. Compression scheme based on Burrows Wheeler Transform is usually lossless ; therefore we imple-ment this algorithm in medical imagi…
Texture classificatication in a cloud computing environment for leaf roughness characterization in precision spraying applications
2010
International audience
ACTIVE3D: SEMANTIC AND MULTIMEDIA MERGING FOR FACILITY MANAGEMENT
2010
International audience; This paper presents a Semantic Web approach for facility management. This Web-based platform lets geographically dispersed project participants--from facility managers and architects to electricians to plumbers--directly use and exchange project documents in a centralized virtual environment using a simple Web browser. A 3D visualization lets participants move around in the building being designed and obtain information about the objects that compose it. This approach is based on a semantic model called CDMF and IFC 2x3. CDMF improves data management during the lifecycle of a building. Based on graph combinations and the contextual element SystemGraph, our propositio…
A Semantic Model to Query Spatial-Temporal Data
2013
International audience; There is a growing need for the study of spatial-temporal objects and their relationships. A common approach for this task is the use of relational databases, which unfortunately do not allow inference. In this research we introduce a new approach that uses the concept of "continuum" together with ontologies and semantic web technologies. The "continuum" allows us to defi ne parent-child relationships between representations of objects. It also allows us to compare the evolution of two diff erent objects and establish the relationships between them along time. Our approach is based on the 4D fluent, which is extended to obtain spatial-temporal qualitative information…
Vers un modeleur géométrique déclaratif
2015
International audience; no abstract
INTEROPERABILITY BETWEEN GIS AND BIM A Semantic-based Multi-representation Approach
2011
International audience; Interoperability of information systems is partially resolved due to many standards such as networks protocols, XML derived languages and object oriented programming. Nevertheless, semantic heterogeneity limits collaborative works and interoperability. Despite ontology and other semantic technics, the binding of heterogeneous information systems requires new technics of managing and displaying information according to the semantic representation of each stakeholder of the collaboration. In this paper we addressed the problem of merging geographical information systems and building information model. The way to achieve this goal must solve several heterogeneity proble…
The spatio-temporal semantics from a perdurantism perspective
2013
International audience; In this paper we present the "continuum model". Our work follows a "perdurantism" approach and is designed to handle dynamic phenomena extending the 4D-fluent with the use of semantic web technologies. In our approach we represent dynamic entities as constituted by time slices each with semantic, geometric and temporal components. Our model is able to link the diverse representations of an entity and allows the inference of qualitative information from quantitative one. The inference results are later added to the ontology in order to enhance the knowledge base. The model has been implemented using OWL and SWRL. Our preliminary results are promising and we plan to fu…
Mise en correspondance de lignes à partir de deux vues, estimation du mouvement et reconstruction pour les systèmes centraux
2011
The primary goal of this thesis is to develop generic motion and structure algorithms for images taken from constructed scenes by various types of central imaging systems including perspective, fish-eye and catadioptric systems. As-suming that the mapping between the image pixels and their 3D rays in space is known, instead of image planes, we work on image spheres (projection of the images on a unit sphere) which enable us to present points over the entire viewsphere suitable for presenting omnidirectional images. In the first part of this thesis, we develop a generic and simple line matching approach for images taken from constructed scenes under a short baseline motion as well as a fast …