School of Engineering and Computing Sciences, University of Durham, Durham, UK. boguslaw.obara@durham.ac.uk|School of Engineering and Computing Sciences, University of Durham, Durham, UK. boguslaw.obara@durham.ac.uk|School of Engineering and Computing Sciences, University of Durham, Durham, UK. boguslaw.obara@durham.ac.uk|School of Engineering and Computing Sciences, University of Durham, Durham, UK. boguslaw.obara@durham.ac.uk