Complex sentence: In the late 1980s Hans Georg Feichtinger and Karlheinz Gröchenig conducted joint research on atomic decompositions and from 1990 on, Feichtinger investigated irregular sampling and computational harmonic analysis with Thomas Strohmer.
Split into simpler sentences: In the late 1980s Hans Georg Feichtinger and Karlheinz Gröchenig conducted joint research on atomic decompositions. From 1990 on, Feichtinger investigated irregular sampling and computational harmonic analysis with Thomas Strohmer.