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Questions tagged [linked-data]

Linked Data refers to a set of best practices for publishing data on the Web under the Semantic Web standards (RDF, SPARQL, etc.). Please consider asking your question on https://opendata.stackexchange.com, if your question is not closely related to programming or is related to a particular Linked Data dataset.

T. Berners-Lee outlines four principles of linked data in his "Linked Data" note:

  1. Use URIs as names for things
  2. Use HTTP URIs so that people can look up those names
  3. When someone looks up a URI, provide useful information, using the standards (RDF*, SPARQL)
  4. Include links to other URIs, so that they can discover more things
371 questions
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Jena Model Validation OntModel

I have created an Ontology which i want use for validating instances, following is the test setup i have, couldnt get validation report one of uid is zero. which is xsd:minExclusive "0"^^xsd:unsignedLong. Can anyone help m eunderstand best practice…
Zafar Ali
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Where have all my labels gone? Topbraid owl to SHACL conversion

I'm trying to convert my ontology, from OWL to SHACL. However, the SKOS labels, preflabels, comments etc. are not being converted. At least, they don't come back in the ttl file that is generated. Right now, I load my original TTL file into…
Robin
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Finding classes which should be instances sparql; Finding classes with exactly 1 subclass

It sounds quite simple but I have not managed to find a nice solution yet. I'm looking to find the classes in my ontology which have exactly one subclass. So far I have approached it as follows: SELECT (COUNT(?anything) AS ?count) ?class WHERE…
Robin
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Why are some of the classes in my ontolgoy not being returned in my SPARQL query?

I'm rather confused about why I'm receiving too little results (256 expected, 224 returned). When I run the code below, everything returns exactly as I want it, except that I miss all the classes in my ontology which lie at the highest level, or one…
Robin
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How to set a locally-provided custom context with Ruby JSON-LD?

I am getting accustomed to the Ruby RDF JSON-LD toolset and currently I'm trying to extract knowledge from plain JSON files which do not carry a JSON-LD context. Therefore I need a way to set a locally-provided context when loading them. So what I…
aef
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Design an RDF / Linked Data API - should I expose data per datagraph or per service?

I am building an API to connect RDF data to a React front-end. The data is stored across several datagraphs. The API has access to all datagraphs. React will call the API to get the data, then display it to users. Most UI views will require data…
Rob G
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Dynamic predicates in SPARQL CONSTRUCT

I'm trying to get only ONE relation in the CONSTRUCT. Please let me introduce the problem.... There is an Actor (actorURI) which has a relation with another Actor (actor2URI). There is only ONE relation possible. With an BIND(IF command i'm trying…
Fina83
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Access statements of Wikidata entities by id

I would like to know if there's a way to find a Wikidata entity by specified property using their API. This is my request:https://www.wikidata.org/w/api.php?action=wbgetclaims&format=json&entity=Q85670252 Output…
SamBack
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How to give a numeric value to an object while writing an rdf triple

I am tryin to write an rdf triple for MixedFruitJuice is made of 2 Oranges, 1 Pomegranate and 1 Pineapple. HereMixedFruitJuice is an instance of class FruitJuiceand Orange Pomegranate and Pineapple are instances of Fruit. I don't understand how I…
Raghav Rathi
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How to get the path details between two nodes in DBpedia in SPARQL

I want to check if two DBpedia nodes have a path using; dct:subject and skos:broader properties without specifying properties For instance consider the two DBpedia nodes; http://dbpedia.org/resource/Cat and http://dbpedia.org/resource/Dog.…
EmJ
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SPARQL Return only IRIs/URIs as result

In SPARQL how do I retrieve only IRIs (or URIs) as a result of a BGP? E.g. in SELECT ?s ?o WHERE {?s ?p ?o } LIMIT 100 Return only those ?o that are IRIs
Kuzeko
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How to use owl:sameAs inferences within Fuseki's Sparql and return every matching instance's properties?

I have the following RDF data in my Fuseki triplestore. @prefix owl: . @prefix schema: . @prefix ex: . @prefix wgs84: …
Bruno
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What is the role of CWA and OWA in semantic web applications?

What role does CWA and OWA play in semantic web applications? How important is it for those developing ontologies, writing SHACL schemas, or generating linked data to keep these concepts in mind?
Alex
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Mapping Wikidata QID to Wikipedia CurID

Two questions: How can I map QID from Wikidata to English Wikipedia CurID using dumps? Which dump to use? I am not looking for an API based solution, as I want to generate this mapping for all wikipedia entities.
The Wanderer
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How to dereference an uploaded URI node in Fuseki2 linked data server?

I installed Fuseki2 and run it as a standalone server with default settings (http://localhost:3030/). I created an in-memory dataset ('geography') by uploading a Turtle file with information like this, through the 'Manage datasets' console: @prefix…
Bruno
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