Affiliation: | (1) School of Mathematical and Computer Science, Heriot-Watt University, Riccarton, EH14 4AS, Edinburgh, Great Britain;(2) Department of Electronic Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK;(3) School of Mathematical and Computer Science, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, Great Britain |