Name That Graph or the need to provide a model and syntax extension to specify the provenance of RDF graphs

International audienceWhen querying or reasoning on metadata from the semantic web, the source of this metadata as well as a number of other characteristics (date, trust, etc.) can be of great importance. While the SPARQL query language provides a keyword to match patterns against named graphs, the RDF data model focuses on expressing triples. In many cases it is interesting to augment these RDF triples with the notion of a provenance for each triple (or set of triples), typically an IRI specifying their real (e.g. author) or virtual origin (e.g. inference engine and entailment regime). This position paper extends on a member submission from INRIA (RDF/XML Source Declaration [1]) expressing the importance for us to provide a standard mechanism in RDF to name graphs. It proposes and discusses an RDF/XML syntax extension providing an attribute to specify the provenance of triples in an RDF/XML representation

Transforming XML to RDF(S) with Temporal Information

The Resource Description Framework (RDF) is a model for representing resources on the Web. With the widespread acceptance of RDF in various applications (e.g., knowledge graph), a huge amount of RDF data is being proliferated. Therefore, transforming legacy data resources into RDF data is of increasing importance. In addition, time information widely exists in various real-world applications and temporal Web data has been represented and managed in the context of temporal XML. In this paper, we concentrate on transformation of temporal XML (eXtensible Markup Language) to temporal RDF data. We propose the mapping rules and mapping algorithms which can transform the temporal XML Schema and document into temporal RDF Schema and temporal RDF triples, respectively. We illustrate our mapping approach with an example and implement a prototype system. It is demonstrated that our mapping approach is valid

RDF Querying

Reactive Web systems, Web services, and Web-based publish/ subscribe systems communicate events as XML messages, and in many cases require composite event detection: it is not sufficient to react to single event messages, but events have to be considered in relation to other events that are received over time. Emphasizing language design and formal semantics, we describe the rule-based query language XChangeEQ for detecting composite events. XChangeEQ is designed to completely cover and integrate the four complementary querying dimensions: event data, event composition, temporal relationships, and event accumulation. Semantics are provided as model and fixpoint theories; while this is an established approach for rule languages, it has not been applied for event queries before

SWI-Prolog and the Web

Where Prolog is commonly seen as a component in a Web application that is either embedded or communicates using a proprietary protocol, we propose an architecture where Prolog communicates to other components in a Web application using the standard HTTP protocol. By avoiding embedding in external Web servers development and deployment become much easier. To support this architecture, in addition to the transfer protocol, we must also support parsing, representing and generating the key Web document types such as HTML, XML and RDF. This paper motivates the design decisions in the libraries and extensions to Prolog for handling Web documents and protocols. The design has been guided by the requirement to handle large documents efficiently. The described libraries support a wide range of Web applications ranging from HTML and XML documents to Semantic Web RDF processing. To appear in Theory and Practice of Logic Programming (TPLP)Comment: 31 pages, 24 figures and 2 tables. To appear in Theory and Practice of Logic Programming (TPLP

Supporting SPARQL Update Queries in RDF-XML Integration

The Web of Data encourages organizations and companies to publish their data according to the Linked Data practices and offer SPARQL endpoints. On the other hand, the dominant standard for information exchange is XML. The SPARQL2XQuery Framework focuses on the automatic translation of SPARQL queries in XQuery expressions in order to access XML data across the Web. In this paper, we outline our ongoing work on supporting update queries in the RDF-XML integration scenario.Comment: 13th International Semantic Web Conference (ISWC '14

Survey over Existing Query and Transformation Languages

A widely acknowledged obstacle for realizing the vision of the Semantic Web is the inability of many current Semantic Web approaches to cope with data available in such diverging representation formalisms as XML, RDF, or Topic Maps. A common query language is the first step to allow transparent access to data in any of these formats. To further the understanding of the requirements and approaches proposed for query languages in the conventional as well as the Semantic Web, this report surveys a large number of query languages for accessing XML, RDF, or Topic Maps. This is the first systematic survey to consider query languages from all these areas. From the detailed survey of these query languages, a common classification scheme is derived that is useful for understanding and differentiating languages within and among all three areas