Geographical Concept Recognition With the Octgrid Method for Learning Geography and Geology. - Ryusuke Yokoyama; Akira Kureha; Tomoe Motohashi; Hiroyasu Ogasawara; Takeo Yaku; Daisuke Yoshino (ICALT, 2007)

A Comparison of Ridge Detection Methods for DEM Data. - Shinji Koka; Koichi Anada; Yasunori Nakayama; Kimio Sugita; Takeo Yaku; Ryusuke Yokoyama (SNPD, 2012)