About: http://webisa.webdatacommons.org/421210135

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	In FIGS. 17(A), (B), (C), and (D), the abscissa is a time, and the above-mentioned signal pulse is generated periodically in the previous time zone (not shown).
http://www.w3.org/ns/prov#wasQuotedFrom	google.com