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).

1956 questions
9
votes
1 answer

Load DBpedia locally using Jena TDB?

I need to perform a query against DBpedia: SELECT DISTINCT ?poi ?lat ?long ?photos ?template ?type ?label WHERE { ?poi ?label . ?poi ?lat . ?poi…
George Papatheodorou
  • 1,539
  • 19
  • 23
9
votes
1 answer

Querying DBpedia with SPARQL and Jena

I cannot understand how can I query DBpedia using Jena. In the tutorials like here(Listing 4) model is initialized as follows: // Open the bloggers RDF graph from the filesystem InputStream in = new FileInputStream(new File("bloggers.rdf")); //…
Eugeniu Torica
  • 7,484
  • 12
  • 47
  • 62
9
votes
3 answers

Can a
element contain only a
without an image?

Is it semantic for a
element to contain nothing but a
? It does validate...
Image and caption
Caption…
Baumr
  • 6,124
  • 14
  • 37
  • 63
9
votes
3 answers

Is a RDF Triple a RDF Statement?

As the subject of the question asks, are the 2 the same thing? Are they interchangeble? If not, please explain the differences or provide clarification with an example.
Eminem
  • 7,206
  • 15
  • 53
  • 95
9
votes
3 answers

Comparison of OData and Semantic Web/Linked Data

I'm trying to get my head around two very different approaches to data sharing: OData and Semantic Web/Linked Data. Is there a good comparison of the two? As I understand it, OData combines syndication/CRUD (AtomPub), serialisation formats (XML,…
Steve Bennett
  • 114,604
  • 39
  • 168
  • 219
8
votes
2 answers

getting count of rdf:list using SPARQL

Is this the correct/best SPARQL query to get the count of items in rdf:list: select (COUNT(?a) AS ?count) where {?a http://www.w3.org/1999/02/22-rdf-syntax-ns#first ?c} Thanks in advance for your help. regards, rahul
user1278577
  • 325
  • 4
  • 7
8
votes
5 answers

dotNetRDF VS Jena.NEt VS others with Dotnet ?

what is the most common tool used for Reading & Writing RDF and Querying with Sparql with different end points . so far i've found Jena (jena.net) : it's developed for Java but some people managed to convert it to Assemblies DotnetRDF i…
Hady Elsahar
  • 2,121
  • 4
  • 29
  • 47
8
votes
1 answer

Semantic Web resources for a new web site?

I want to implement a web site from scratch using Semantic Web as much as possible. My website will be for a scientific institution, I have no model but I recognize there are entities/objects like Person and Person Roles (Researcher, Teacher,…
user183928
  • 783
  • 3
  • 9
8
votes
2 answers

What are the Best Practices in developing semantic application using Jena & RDF

Semantic Web: Best Practices I am new to Semantic Web, in my application, I'm using Protege,RDF,SPARQL,Jena,Virtuaso. My concern is, in popular Java Frameworks (like Hibernate), we have POJO layer, in this Semantic Web application can I have the…
pc_
  • 131
  • 5
8
votes
1 answer

Instances vs Classes in RDFS

The description of the base classes defined by RDFS in the W3C reference document states that some classes are instances of one class and a subclass of another (or in some cases an instance and subclass of the same class). Coming from a more…
8
votes
3 answers

Displaying Relations in Protege-OWL Editor

I have created a basic Class hierarchy for my ontology in Protege-OWL Editor version 4.1. But I am not able to visualise Object Properties and relations between the classes in OwlViz other than the normal hierarchy or "is-a" relationship. So please…
A_tanA
  • 143
  • 1
  • 7
8
votes
4 answers

Why is OWL Full undecidable?

I've been looking all around on why OWL Full is undecidable, but I haven't found an easy to understand example that would lead me to comprehend it. I've found statements that explain that it is due to "Entailment Closure" and that is also correlated…
8
votes
1 answer

Use Jena to query wikidata

Currently, Wikidata has a SPARQL endpoint "https://query.wikidata.org/", I would like to query this site using Jena (3.0.1), I use the following code but I got an error message "Endpoint returned Content-Type: text/html which is not currently…
Mostafa abdo
  • 616
  • 1
  • 8
  • 21
8
votes
1 answer

Reading a Turtle/N3 RDF File with Python

I'm trying to encode some botanical data in Turtle format, and read this data from Python using RDFLib. However, I'm having trouble, and I'm not sure if it's because my Turtle is malformed or I'm misusing RDFLib. My test data is: @PREFIX rdf:…
Cerin
  • 60,957
  • 96
  • 316
  • 522
8
votes
2 answers

How can I express additional information (time, probability) about a relation in RDF?

I know that I can represent any relation as a RDF triplet as in: Barack Obama -> president of -> USA (I am aware that this is not RDF, I am just illustrating) But how do I add additional information about this relation, like for example the time…
nanounanue
  • 7,942
  • 7
  • 41
  • 73