PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • I have considered a lot of alternatives, but using a 3d compass seems to be unavoidable. 3d compass is notorious for its difficulty in calibration, and its inaccuracy due to electromagnetic interference, especially if you have a motor or servo somewhere in your robot.
http://www.w3.org/ns/prov#wasQuotedFrom
  • berkeley.edu