1. Department of Mathematics
and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH, United Kingdom
2. School of Engineering, University of Edinburgh, The King’s
Buildings, Mayfield Road, Edinburgh, EH9 3JL, United Kingdom
3. International Institute for
Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744
Motooka, Nishi-ku, Fukuoka 819-0395, Japan