which subclass of information filtering system was work of John Thomas Riedl
John T. Riedl John Thomas Riedl (January 16, 1962 – July 15, 2013) was an American computer scientist and the McKnight Distinguished Professor at the University of Minnesota. His published works include highly influential research on the social web, recommendation systems, and collaborative systems.
Filter bank In signal processing, a filter bank is an array of band-pass filters that separates the input signal into multiple components, each one carrying a single frequency sub-band of the original signal. One application of a filter bank is a graphic equalizer, which can attenuate the components differently and recombine them into a modified version of the original signal. The process of decomposition performed by the filter bank is called "analysis" (meaning analysis of the signal in terms of its components in each sub-band); the output of analysis is referred to as a subband signal with as many subbands as there are filters in the filter bank. The reconstruction process is called "synthesis", meaning reconstitution of a complete signal resulting from the filtering process.