About: http://webisa.webdatacommons.org/109388716

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 the example illustrated in FIG. 1, the DC power signal is a pulse wave generating a constant current level during a time period from t1 to t2 and during other time periods, such as from t3 to t4.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com