With the quick development of the semantic web technology, RDF data explosion has become a challenging problem. Since RDF data are always from different resources, which may have overlap with each other, they could have duplicates. These duplicates may cause ambiguity and even error in reasoning. However, attentions are seldom paid to this problem. In this paper, we study the problem and give a...

The RDF data model is a key technology in the Linked Data vision. Given its graph structure, even relatively simple RDF queries often involve a large number of joins. Join evaluation poses a significant performance challenge on all state-of-the-art RDF engines. TripleT is a novel RDF index data structure, demonstrated to be competitive with the current state-of-the-art for join processing. Quer...

Today a large amount of RDF data is published on the Web. However, the openness of the Web and the ease to combine RDF data from different sources creates new challenges. The Web of data is missing a uniform way to assess and to query the trustworthiness of information. In this paper we present tSPARQL, a trust-aware extension to SPARQL. Two additional keywords enable users to describe trust re...

Information retrieval is the essential task for Traffic Information Service System in Intelligent Transportation Systems (ITS). There a lot of fuzzy traffic information derived from human factor. To achieve fuzzy semantic retrieval, this paper proposes an approach using Resource Description Framework (RDF) and fuzzy ontology. First, we apply RDF data model to represent traffic information on th...

The Clinical Quality Language (CQL) is a HL7 specification, aiming to provide a human-readable language to define clinical quality measures and decision support rules while it makes logic expressions independent of any specific data model (e.g., Quality Data Model, HL7 Fast Healthcare Interoperability Resources – FHIR). FHIR adopts RDF as its third representation/interchange format in addition ...

RDF is a data model to represent positive information. Consequently, it is not clear how to represent the non-existence of information in RDF. We present a technique to express such information in RDF and incorporate it into SPARQL query answering. Given an empty query answer, our technique can distinguish whether it is empty due to possibly incomplete information, or non-existent information.

In this paper we examine how Discretionary Access Control principles, that have been successfully applied to relational and XML data, can be applied to the Resource Description Framework (RDF) graph data model. The objective being to provide a baseline for the specification of a general authorisation framework for the RDF data model. Towards this end we provide a summary of access control requi...

In this demo we present RDFauthor, an approach for authoring information that adheres to the RDF data model. RDFauthor completely hides syntax as well as RDF and ontology data model difficulties from end users and allows to edit information on arbitrary RDFaannotated web pages. RDFauthor is based on extracting RDF triples from RDFa-annoted Web pages and transforming the RDFa-annotated HTML view...

A difficult task when generating text from knowledge bases (KB) consists in finding appropriate lexicalisations for KB symbols. We present an approach for lexicalising knowledge base relations and apply it to DBPedia data. Our model learns lowdimensional embeddings of words and RDF resources and uses these representations to score RDF properties against candidate lexicalisations. Training our m...

In this paper we investigate and formalize the notion of RDF Models (or context) for RDF data by defining syntax and a model theoretic semantics of TRIPLE, a logic for dealing with RDF and contexts. A unique feature of the language is that one context can be used as parameters for other contexts. The definitions are used to derive a query and reasoning language based on deductive database techn...