[1] CAD Centre, Department of Design Manufacture and Engineering Management, University of Strathclyde, Glasgow G1 1XJ, United Kingdom
[2] Intelligent Interactive Distributed Systems Group, Department of Computer Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
[3] CAD Centre, Department of Design Manufacture and Engineering Management, University of Strathclyde, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom