1. Applied Algebra and Optimization Research Center, Department of Mathematics, Sungkyunkwan University, Suwon, South Korea
2. Department of Mathematical Sciences, Seoul National University, Seoul, South Korea
3. Department of Mathematics, Technion – Israel Institute of Technology, Haifa, Israel
4. Department of Computer and Information Sciences, University of Strathclyde, Glasgow, Scotland, United Kingdom
5. Sobolev Institute of Mathematics, Novosibirsk State University, Novosibirsk, Russia