semantic-web

Given a choice between OWL Property Restrictions and SHACL , is there any reason to choose the OWL approach any more? Particularly with respect to cardinality constraints, I'm wondering whether SHACL is considered to supercede OWL. The syntax appears similar, to my casual inspection. I am probably missing the purpose of OWL cardinality constraints. As part of an ontology, they should facilitate inferencing (a separate concern from validation). But how do cardinality constraints facilitate inferencing? The differences between OWL and SHACL are presented in the table below. | OWL | SHACL | |----

Maybe someone could give me a hint. Is it possible to measure the distance between 2 concepts/classes that belong to the same ontology? For example, let's suppose I have an ontology with the Astronomy class and the Telescope class. There is a link between both, but it is not a direct link. Astronomy has a parent class called Science, and Telescope has a parent class called Optical Instrument which belongs to its parent called Instrumentation, that is related to a class called Empirical Science that finally belongs to a class called Science. So there is an indirect link between Telescope and

I'm working on a RESTful service and have been focusing on Discoverability, Link relations - 'rel' and microformats. I'm not clear about the values of 'rel' in the context of REST - am I allowed to make use of any custom value, to provide richer semantics or should I only use the default values (which are very constraining)? I am aware that microformats have indeed extended the values of 'rel', but I am not using any kind of microformat yet. Any help is appreciated. Thanks. Link Relations (rel) are one of the two ways that you can convey semantics to a client. The other way is media types. The

I read this blog article, Problems of the RDF model: Blank Nodes , and there's mentioned that using blank nodes can complicate the handling of data. Can you give me an example why using blank nodes is difficult to perform a SPARQL query? I do not understand the complexity of blank nodes. Can you explain me the meaning and semantics of an existential variable? I do not understand clearly this explanation given in the RDF Semantics Recommendation, 1.5. Blank Nodes as Existential Variables . Joshua Taylor Existential Variables In the (first-order) predicate calculus, there is existential

I'm looking to use SPARQL for a relatively basic task: Given a FOAF graph, I'd like to parse the elements I find in there, get their tags (if they exist) and then, use those as new graphs from which to find information about those people. So for instance, you could imagine a simple use case where I want to run a SPARQL query to list all of my favorite foods (as per my FOAF file), and also the favorite foods of all my friends. Here is what this looks like at the moment. Note that for testing purposes, at the moment all I'm trying to do with the query below is fetch the name of the friend,