1. Department of Mechanical and Process Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, Tannenstrasse 3, Zurich CH-8092, Switzerland
2. Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784, Republic of Korea