The photo, taken in 1990 by Marco Campi, groups people belonging to or cooperating with the "Center of System Theory" (CST) of the CNR -National Research Council. The CST was established in 1971 as a formal research group based on the convention CNR - Politecnico di Milano. From its foundation until 1991, CST was hosted at DEI (Department of Electronics and Information) under the direction of Professor Emanuele Biondi (blue jacket, mid centre of the second row) and then (1991-1997) by Professor Arturo Locatelli (third from left, back row). This picture was taken at the meeting when the change of director was announced.