Search results for "Temporal"

Pasajes de París / 2; Walter Benjamin

2006

On the influences of vegetation biomass on COSMO-Skymed X-band

2011

The knowledge of spatial and temporal variability of land cover is important to manage water resources for yield forecasting, water stress prediction, irrigation water management and flood protection. Cloud cover dramatically reduces the temporal resolution of optical data thus limiting their operational use; in addition, the spatial resolution is often inadequate for applications in heterogeneous areas. On the other hand, algorithms based on Synthetic Aperture Radar (SAR) implemented to retrieve vegetation parameters are not yet fully validated. New SAR missions (COSMO-Skymed and Terrasar-X) may represent a suitable source of data for operational uses due to the high spatial and temporal r…

Temporal incoherent solitons supported by a defocusing nonlinearity with anomalous dispersion

2012

http://pra.aps.org/; International audience; We study temporal incoherent solitons in noninstantaneous response nonlinear media. Contrarily to the usual temporal soliton, which is known to require a focusing nonlinearity with anomalous dispersion, we show that a highly noninstantaneous nonlinear response leads to incoherent soliton structures which require the inverted situation: In the focusing regime (and anomalous dispersion) the incoherent wave packet experiences an unlimited spreading, whereas in the defocusing regime (still with anomalous dispersion) the incoherent wave packet exhibits a self-trapping. These counterintuitive results are explained in detail by a long-range Vlasov formu…

LC3 A Spatial-temporal Data Model to Study Qualified Land Cover Changes

2015

International audience; Land cover changes caused by humans have reached points never witnessed in history before. Consequences of these changes are environmental degradation, pollution of water, biodiversity loss and climate change among others. It is in this frame that the interest of the scientific community for this type of events has increased in the last decades. Nowadays, researchers have access to sophisticated monitoring tools and techniques. However, the new threat is that over abundance of information would hide relevant facts and processes. In our research we use data from the CORINE (Coordination of Information on the Environment) program. This program has compiled land cover i…

Using Semantic Web Technologies to Follow the Evolution of Entities in Time and Space

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 timeslices each with semantic, geometric, temporal and identity 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 improve knowledge about the phenomenon. The model has been implemented using OWL and SWRL. Our preliminary results are promis…

SCALESEM : Evaluation of Semantic Graph based on Model Checking

2011

International audience; Semantic interoperability problems have found their solutions using languages and techniques from the Semantic Web. The proliferation of ontologies and meta-information has improved the understanding of information and the relevance of search engine responses. However, the construction of semantic graphs is a source of numerous errors of interpretation or modelling and scalability remains a major problem. The processing of large semantic graphs is a limit to the use of semantics in current information systems. The work presented in this paper is part of a new research at the border of two areas: the semantic web and the model checking. This line of research concerns …

RDF2SPIN: Mapping Semantic Graphs to SPIN Model Checker

2011

International audience; The most frequently used language to represent the semantic graphs is the RDF (W3C standard for meta-modeling). The construction of semantic graphs is a source of numerous errors of interpretation. The processing of large semantic graphs is a limit to the use of semantics in current information systems. The work presented in this paper is part of a new research at the border between two areas: the semantic web and the model checking. For this, we developed a tool, RDF2SPIN, which converts RDF graphs into SPIN language. This conversion aims checking the semantic graphs with the model checker SPIN in order to verify the consistency of the data. To illustrate our propos…

Extending SPARQL with Temporal Logic

2009

The data integration and sharing activities carried on in the framework of the Semantic Web lead to large knowledge bases that must be queried, analyzed, and exploited efficiently. Many of the knowledge representation languages of the Semantic Web, starting with RDF, are based on directed, labeled graphs, which can be also manipulated using graph algorithms and tools coming from other domains. In this paper, we propose an analysis approach of RDF graphs by reusing the verification technology developed for concurrent systems. To this purpose, we define a translation from the SPARQL query language into XTL, a general-purpose graph manipulation language implemented in the CADP verification too…

Qualifying semantic graphs using model checking

2011

International audience; Semantic interoperability problems have found their solutions using languages and techniques from the Semantic Web. The proliferation of ontologies and meta-information has improved the understanding of information and the relevance of search engine responses. However, the construction of semantic graphs is a source of numerous errors of interpretation or modeling and scalability remains a major problem. The processing of large semantic graphs is a limit to the use of semantics in current information systems. The work presented in this paper is part of a new research at the border of two areas: the semantic web and the model checking. This line of research concerns t…

A new approach based on NμSMV Model to query semantic graph

2011

International audience; The language most frequently used to represent the semantic graphs is the RDF (W3C standard for meta-modeling). The construction of semantic graphs is a source of numerous errors of interpretation. Processing of large semantic graphs can be a limit to use semantics in modern information systems. The work presented in this paper is part of a new research at the border between two areas: the semantic web and the model checking. For this, we developed a tool, RDF2NμSMV, which converts RDF graphs into NμSMV language. This conversion aims checking the semantic graphs with the model checker NμSMV in order to verify the consistency of the data. The data integration and shar…