Search results for "RDF Schema"
showing 7 items of 7 documents
Querying Dynamic and Context-Sensitive Metadata in Semantic Web
2005
RDF (core Semantic Web standard) is not originally appropriate for context representation, because of its initial focus on the ordinary Web resources, such as web pages, files, databases, services, etc., which structure and content are more or less stable. However, on the other hand, emerging industrial applications consider e.g. machines, processes, personnel, services for condition monitoring, remote diagnostics and maintenance, etc. to be specific classes of Web resources and thus a subject for semantic annotation. Such resources are naturally dynamic, not only from the point of view of changing values for some attributes (state of resource), but also from the point of view of changing “…
COMPOSITION OF REFUSE DERIVED FUELS IN LATVIA AND ESTONIA IN COMPARISION WITH WORLDWIDE AVERAGE VALUES
2019
Information about composition of RDF worldwide was collected using literature analysis. RDF samples produced in Latvia and Estonia were collected, those fractional and elemental composition analyzed using standard methods. Comparing obtained results with worldwide data we have found that the quality of local RDFs in general is higher than typical values, while elevated content of chlorine must be mentioned as a problem. Results also show that majority of chlorine in studied samples exists in organic form. Recommendations to overcome this problem have been developed.
A framework for context-sensitive metadata description
2006
Expectations regarding the new generation of Web depend on the success of Semantic Web technology. Resource Description Framework (RDF) is a basis for explicit and machine-readable representation of semantics. However RDF is not suitable for describing dynamic and context-sensitive resources (eg. processes). We present the Context Description Framework (CDF) as an extension of the RDF by adding a 'TrueInContext' component to the basic RDF triple ('subject-predicate-object'), and consider contextual value as a container of RDF statements. We also add a probabilistic component, which allows multilevel contextual dependence descriptions as well as presumes possibility for Bayesian reasoning wi…
Export of Relational Databases to RDF Databases by Model Transformations
2011
The Semantic Web is a Web of Data. To fulfill this web with data we need methods how to transfer business data from existing relational databases. In most cases, textual mapping languages are used for the specification of correspondences between relational DB schema and OWL ontology. These languages generally are rather awkward and not well-suited for the specification of mappings in cases when there is a substantial semantic gap between the source ER schema and the target OWL ontology. At the same time specification of mappings is a classical use case for graphical model transformation languages. In our previous work [10] we have proposed a new, model transformation-based method for the sp…
SILKNOWViz: Spatio-Temporal Data Ontology Viewer
2019
Interactive visualization of spatio-temporal data is a very active area that has experienced remarkable advances in the last decade. This is due to the emergence of fields of research such as big data and advances in hardware that allow better analysis of information. This article describes the methodology followed and the design of an open source tool, which in addition to interactively visualizing spatio-temporal data that are represented in an ontology, allows the definition of what to visualize and how to do it. The tool allows selecting, filtering and visualizing in a graphical way the entities of the ontology with spatiotemporal data, as well as the instances related to them. The grap…
Cu Polyimidazole Thioether Complexes : Comparison of RDF's Reconstructed from XAFS and XRD Data
1997
Radial distribution functions (RDF) reconstructed from XAFS data (Cu K-edge at low and room temperatures) are compared with RDF's constructed from XRD crystallographic data of Cu polyimidazole thioether complexes. New EDA software package possibilities are used to reconstruct RDFs: (i) model independent RDF reconstruction, and (ii) multi shell - cumulant fitting. RDF's obtained from XRD data are broadened with Debye Waller factors calculated from XAFS. This way the structural disorder (set of distances) and thermal (vibrational) disorder are quantitatively taken into account in each RDF reconstruction approach. Within experimental error the three sets of RDF'S agree well with each other for…