1. a Computing and Electrical Engineering Department Heriot-Watt University Riccarton, Edinburgh, EH14 4AS, Scotland
2. b Computing and Electrical Engineering Department Heriot-Watt University Riccarton, Edinburgh, EH14 4AS, Scotland
3. c Computing and Electrical Engineering Department Heriot-Watt University Riccarton, Edinburgh, EH14 4AS, Scotland
4. d Ansoft Corporation London, England
5. e Computing and Electrical Engineering Department Heriot-Watt University Riccarton, Edinburgh, EH14 4AS, Scotland