Estimation of the restitution coefficient by strain measurement Naoya Nishimura, Katsuhiko Murase, Takeru Watanabe, Keisuke Niimi and and Makoto Fukuhara EPJ Web of Conferences, 94 (2015) 01006 Published online: 07 September 2015 DOI: 10.1051/epjconf/20159401006