Using OpenCyc RDF/OWL data in StarDog

Originally published August 7, 2013

Over the years I have used the OpenCyc runtime system to explore and experiment with the OpenCyc data that consists of 239K terms and 2 million triples. In order to test the ease of use of the RDF OWL OpenCyc data I tried loading the OpenCyc OWL file into StarDog:

$ ./stardog-admin server start
$ ./stardog-admin db create -n opencyc ~/Downloads/opencyc-2012-05-10-readable.owl
Bulk loading data to new database.
Loading data completed...Loaded 3,131,677 triples in 00:00:47 @ 65.8K triples/sec.
Successfully created database 'opencyc'.

After you load the data you can experiment with the StarDog command line SPARQL interface. You use the interface to enter SPARQL queries one at a time: 

./stardog query opencyc "SELECT ?s ?p ?o WHERE { ?s ?p ?o } LIMIT 10"
Here are some SPARQL queries to get you started using the command line interface (I am only showing the SPARQL queries): 
SELECT ?s ?p ?o WHERE { ?s ?p ?o FILTER(REGEX(?o, "Clinton")) } LIMIT 30
SELECT ?p ?o WHERE { :HillaryClinton ?p ?o } LIMIT 30
SELECT ?o WHERE { :HillaryClinton :wikipediaArticleURL ?o }
Notice that OpenCyc terms like :HillaryClinton are in the default namespace. The results for this last query are: 
+-------------------------------------------------------+
|                           o                           |
+-------------------------------------------------------+
| "http://en.wikipedia.org/wiki/Hillary_Rodham_Clinton" |
+-------------------------------------------------------+
You can easily convert WikiPedia URLs to DBPedia URIs; for example, this URL would as a DBPedia URI would be <http://dbpedia.org/data/Hillary_Rodham_Clinton> and using the DBPedia live SPARQL query web app you might want to try the SPARQL query: 
SELECT ?p ?o WHERE { dbpedia:Hillary_Rodham_Clinton ?p ?o } LIMIT 200
Some RDF repositories support the new SPARQL 1.1 feature of specifying additional SPARQL SERVICE end points so queries can combine triples from difference services. Bob DuCharme covers this in his book "Learning SPARQL" at the end of Chapter 3. Without using multiple SPARQL SERVICE end points you can still combine data from multiple services on the client side; for example: combine query results of multiple queries from a local StarDog or Sesame server with the remote DBPedia endpoint.

Comments

Post a Comment

Popular posts from this blog

My Dad's work with Robert Oppenheimer and Edward Teller

Robert Oppenheimer and Edward Teller facilitated my Dad getting a professorship at UC Berkeley when I was 3 years old. Oppenheimer left Berkeley but Teller was a good friend of my father and I remember him being in our home. Three weeks ago, my wife and I were just leaving to see the new Oppenheimer movie when my Dad called. He mentioned that when I was in grade school he was invited to give a talk at Princeton. After his talk Oppenheimer talked with my Dad and invited him to have dinner at his house. My Dad said Oppenheimer was not well (I think he died of throat cancer soon afterwards) but his wife Kitty carried the conversation. My Dad, Ken Watson, passed away 10 days ago on August 18, 2023.
Read more

Ruby Sinatra web apps with background work threads

In Java-land, I have often used the pattern of writing a servlet with an init() method that starts up one or more background work threads. Then while my web application is handling HTTP requests the background threads can be doing work like fetching RSS feeds for display in the web app, perform periodic maintenance like flushing old data from a database, etc. This is a simple pattern that is robust and easy to implement with a few extra lines of Java code and an extra servlet definition in a web.xml file. In Ruby-land this pattern is even simpler to implement: require 'rubygems' require 'sinatra' $sum = 0 Thread.new do # trivial example work thread while true do sleep 0.12 $sum += 1 end end get '/' do "Testing background work thread: sum is #{$sum}" end While the main thread is waiting for HTTP requests the background thread can do any other work. This works fine with Ruby 1.8.7 or any 1.9.*, but I would run this in JRuby for a lon
Read more

Time and Attention Fragmentation in Our Digital Lives

  As humans we have evolved over a few million years to be both attentive and reactive to danger, live in social communities, and spend much of our time being in the present moment gathering and eating food and socializing. The behavior of rapidly changing short attention to content on social media, too many good short form things to watch on streaming video entertainment platforms, are all rewiring our brains in an unnatural and unhealthy way. I fight back, but in really simple ways that entail little ceremony: Almost every morning I spend 30 minutes scanning Hacker News (about 10 minutes), Apple News (about 5 minutes), and the remaining time on Twitter and Mastodon finding interesting new (mostly tech) things. I make notes in a temporary Apple Note: links of things I may want to research, try, or simply read that day. I like to get this all done at once, and then not feel like I need to interrupt my activities during the day to “catch up” on what is happening in the world. In a way,
Read more