Formulation of Mobile Agent Allocation and its Strong NP-Completeness. - Atsushi Sasaki; Tadashi Araragi; Shigeru Masuyama; Keizo Miyata (IEICE Trans. Inf. Syst., 2005)

Np-hardness proof and an approximation algorithm for the minimum vertex ranking spanning tree problem. - Keizo Miyata; Shigeru Masuyama; Shin-ichi Nakayama; Liang Zhao 013 (Discret. Appl. Math., 2006)