About: http://webisa.webdatacommons.org/203539273

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	The periodicity of the grid pattern in the y-direction is Py=M(Dy/N), where N is a positive integer greater than or equal to 1, M???N and Py=|tan(??)|Px.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com