In this article, we provide a comprehensive introduction to knowledge graphs, which have
recently garnered significant attention from both industry and academia in scenarios that …

RDF has seen increased adoption in recent years, prompting the standardization of the
SPARQL query language for RDF, and the development of local and distributed engines for …

Graph databases have received much attention as of late due to numerous applications in
which data is naturally viewed as a graph; these include social networks, RDF and the …

Abstract shacl (Shapes Constraint Language) is a specification for describing and validating
RDF graphs that has recently become a W3C recommendation. While the language is …

We present a formal semantics and proof of soundness for shapes schemas, an expressive
schema language for RDF graphs that is the foundation of Shape Expressions Language …

Social Network Analysis (SNA) has become a very important and increasingly popular topic
among researchers in recent years especially after emerging Semantic Web and Big Data …

Navigational queries over RDF data are viewed as one of the main applications of graph
query languages, and yet the standard model of graph databases—essentially labeled …

When querying an Resource Description Framework (RDF) graph, a prominent feature is the
possibility of extending the answer to a query with optional information. However, the …

The problem of querying RDF data is a central issue for the development of the Semantic
Web. The query language SPARQL has become the standard language for querying RDF …

Semantic Web, and its underlying data format RDF, lend themselves naturally to
navigational querying due to their graph-like structure. This is particularly evident when …