About: http://webisa.webdatacommons.org/281507272

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Then, the y-axis direction of the local coordinate system is determined as the direction that is perpendicular to the normal vector and that is perpendicular to the plane including both the incident and exiting rays.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es