376 questions
Score of 2
0 answers
73 views
Why does this query timeout while this similar one does not?
I wanted to know for each president, in what state were they born, so I wrote this Wikidata query:
SELECT * WHERE {
# P31 = instance of
# Q5 = human (excludes fictional characters)
?president ...
- reputation score 5593
Score of 0
0 answers
47 views
Linked data: relative URIs of fragments
I am working on an Linked Data / RDF implementation. Following https://www.w3.org/TR/ldp-bp/#use-relative-uris I would like to use relative URIs in sub-graphs. (NOTE that while the referenced best ...
- reputation score 1020
Score of 0
1 answer
80 views
Using RDF nodes from W3C standards in Linked Data ontologies
Is it good/tolerable practice to use elements from W3C standards in a (wannabe five-star) Linked Open Data Ontology?
For example, there is fo:region-body, which is an element of the XSL-FO standard (...
- reputation score 937
Score of 1
0 answers
68 views
BPMN process engine which consumes data from KGs
I am involved in a project and I would like to ask for some advice, opinion, ideas...
The thing is that we have some data stored in a triple-store (GraphDB), with some related ontologies, SHACL rules ...
- reputation score 41
Score of 1
1 answer
208 views
Import object properties in OWL ontology
I am a beginner in Linked Data and ontologies. I import CIDOC ontology to mine, in order to use some of its classes and properties. I have an owl file and in ttl syntax, I do
@prefix cidoc: <http://...
- reputation score 4006
Score of 0
0 answers
44 views
Which geometry serializations to include in GeoSPARQL RDF?
I am generating RDF triples for a dataset, and want to support GeoSPARQL. Given a geo:Geometry, multiple geometry serializations can be attached. Some of the options include geo:asGeoJSON, geo:asWKT, ...
- reputation score 1605
Score of 0
0 answers
79 views
Generate OWL from RDF generated data
I have simple relational database tables
drugs (drug_id(PK), traditional_name, category, factory_id(FK) ....)
chemical composition (Id(PK), scientific_name, ... )
drugs_compositions (Id(pk), drug_id, ...
- reputation score 6566
Score of 1
0 answers
141 views
Is there a way to prevent WebVOWL creating undefined union classes?
I'm working on a digital humanities project where I'm trying to use WebVowl to visualise an ontology I made in Protégé. When I import the ontology into WebVowl it generates a lot of undefined union ...
- reputation score 11
Score of 1
1 answer
109 views
How to set up the ID of a json element in rdflib
Context
I am loading a rdf file in rdflib, and am trying to export it in json-ld.
The original rdf looks like:
<cim:Substation rdf:ID="_1234">
<cim:IdentifiedObject.name>A ...
- reputation score 3121
Score of 1
0 answers
85 views
With multiple SERVICE clauses and large numbers of relationships in the path, how to execute SPARQL federated query statement?
Regarding the following SPARQL federated query statements:
There are over 10000 ?s2 related to ?s1
There are over 10000 ?s3 related to the previously found ?s2
There are over 10000 ?s4 related to the ...
- reputation score 75
Score of 1
0 answers
255 views
What's the principle of SPARQL `SERVICE` clause query?
I know that SPARQL federated query engine (such as Jena) decomposes it into individual SPARQL based on Service, then sends it to the specified SPARQL endpoint for execution, and finally combines the ...
- reputation score 75
Score of 0
0 answers
44 views
DBPedia Query not returning All I need
I want to retrieve from DBpedia all the states and territories in India as well as all the cities contained in them. I have a long query that does a UNION and returns the territories but not any ...
- reputation score 139
Score of 1
1 answer
86 views
What is the logic of the SPARQL CONSTRUCT LIMIT?
What is the logic of LIMIT when using CONSTRUCT queries in SPARQL?
When I use CONSTRUCT to query DBpedia, I find that the results sometimes don't match the LIMIT
Example
SPARQL:
CONSTRUCT {
?s a ?...
- reputation score 75
Score of 1
1 answer
121 views
Specify subframe for elements of id-value property map in a JSON-LD frame
I am trying to write a JSON-LD frame that serializes some RDF documents in a consistent way. Currently, the RDF is being parsed out from JSON-LD that is correctly structured and I would like the frame ...
- reputation score 1440
Score of 1
1 answer
708 views
Is the Knowledge Graph and the Linked Open Data the same thing?
I started to dive into the topic "Knowledge Graph" and I get the feeling that this is the same as the "Linked Open Data". I have some questions 1) If so, why did they need to ...
- reputation score 458