Questions tagged [semantic-web]

Representation of database record subjects (a/k/a keys, IDs, entities), predicates (a/k/a columns, attributes), and objects (a/k/a values) as triples, where the first two are always URIs, and the third is either a URI or a literal; enabling humans and machines to more easily share, merge, and evaluate data from heterogeneous origins.

The Semantic Web (Web 3.0) provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by the W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework (RDF).

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Where is my mistake in this SPARQL query?

"@PREFIX xsd: " + "SELECT ?o ?stringTest ?boolTest " + "where { "+ "?s ?p ?o . "+ "BIND (xsd:string(?o) as ?stringTest). " + "BIND (xsd:boolean(?o) as…
Isidora Bojovic
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cannot query from local owl using php ARC2

i was developing a website using php (i used ARC2 library) that uses OWL as a backend like mysql, but i can not query and get any result... please please help :( here is the full code that i was trying...
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Can somebody tell me how to list all the users from the ontology in eclipse?

public class Main { public static void main(String args[]){ //read an ontology String filename = "IOTOntology.owl"; Model model = ModelFactory.createDefaultModel(); OntModel model1 =…
Isidora Bojovic
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how to query sibling Classes in "DOID" ontology?

I am using ontobee to execute a query to get all siblings of "essential Hypertension" in human Disease Ontology "DOID", The query returns 5 triples. prefix rdf: prefix owl:…
Eng. Samer T
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SPARQL - select from skos:category - Virtuoso 37000

I have problem with SPARQL. I want to select something from category. For example subjects. I make query like this in http://dbpedia.org/snorql. SELECT ?category ?subject WHERE { ?category a skos:Concept . ?category skos:Concept:…
Cezary
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RDF4J only scheduling 5 Queries against a Triple Store

I have some more Issues with handling semantic data technologies: I have a GraphDB Triplestor running locally on my machine an try to schedule some SPARQL queries against it using RDF4J and Java. As you can see from the code below 10 Queries shall…
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EasyRDF - SPARQL querying DBpedia - "Undefined namespace prefix" error

It's my first question. I am making a simple program to query DBpedia. I use PHP API + EasyRdf RDF Library for PHP. The SPARQL query is correct; it's working fine on http://dbpedia.org/snorql. I can use query for API example; it is also correct. I…
Cezary
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How to get dct:subjects for all entities using SPARQL

I am using the following query PREFIX dct: SELECT ?subject WHERE { ?concept rdfs:label 'Exoskeleton'@en ; ^dct:subject ?subject . } ORDER BY ?subject This doesn't give me any results. However, the…
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Parsed content is in reverse order

I am trying to parse OWL2 file by using OWL API. But I have a problem when I am trying to parse label . Please see the example below.
Xinze LYU
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SPARQL queries gives different answers on different servers

I am trying to run the following sparql query : PREFIX dct: select distinct ?subject where { ?concept rdfs:label 'Artificial intelligence'@en . ?concept ^dct:subject ?subject . } LIMIT 100 When I run this on…
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SPARQL query on rdf:resource with /

I want to know if I can insert something like this in my Triplestore. PREFIX urlStore: INSERT DATA {:yyy :Has_xxx urlStore:D4/readmmd.txt} The problem is /.
armon d
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How to get Literal from sqarqlResultset - dotnerRdf

I get a result from query bellow, how I get 18. | query result | code
Thiện Sinh
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Check if an individual is an instance of a class using OWL in Java

How do you check if an individual is an instance of a class java OWL? I was thinking about getting all the instances of a class and checking if that instance belongs to that set.
CRB
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Predicate as the subject of another triple

Lets says I have a RDF triple store that has :Person1 :hasLocation :Location1. Am I allowed to create other triples with :hasLocation as subject/object? (examples below): :hasLocation rdf:Type :LocationPredicates. :hasLocation rdfs:label…
DRSK
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OWL API in Android, app stops working

I'm trying to use OWL API in Android in order to manage OWL ontologies. I've just started but my app stops working when instantiating the manager and the ontology. I'm using owlapi-distribution-4.1.4 and I added the jar file to the app/libs folder.…
paola91
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