About: http://webisa.webdatacommons.org/89961494

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	An example of such a system is provided with a light emitting element and a pair of light receiving elements.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com