The papers contained in this volume were presented orally at the seventh POLYMODEL conference, held at Sunderland Polytechnic in the United King dom in May 1984 and sponsored by Barclays Bank PLC and Imperial Chemical Industries Ltd. The conferences are organised annually by the North East of England Polytechnic's Mathematical Modelling and Computer Simulation Group - POLYMODEL. The Group is a non-profit making organisation based on the mathematics department of the three polytechnics in the region and has membership drawn from those educational institutions and from regional industry. Its...