About: http://webisa.webdatacommons.org/137249340

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 modern technology, the square wave is mainly used in electronics and signal processing like the movement of a clock or in primitive times, the beating of a drum for it only contains odd harmonics.
http://www.w3.org/ns/prov#wasQuotedFrom	spiritualforums.com