About: http://webisa.webdatacommons.org/246568106

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	When the input a is a time-domain signal and A = fft(a), np.abs(A) is its amplitude spectrum and np.abs(A)**2 is its power spectrum.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com