About the Authors

Sho Otsuka

otsuka.s@lab.ntt.co.jp

Affiliation NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan

Minoru Tsuzaki

Affiliation Kyoto City University of Arts, 13-6 Kutsukake-cho, Oe, Nishikyo-ku, Kyoto 610-1197, Japan

Junko Sonoda

Affiliation Kyoto City University of Arts, 13-6 Kutsukake-cho, Oe, Nishikyo-ku, Kyoto 610-1197, Japan

Satomi Tanaka

Affiliation Kyoto City University of Arts, 13-6 Kutsukake-cho, Oe, Nishikyo-ku, Kyoto 610-1197, Japan

Shigeto Furukawa

Affiliation NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan

Competing Interests

Shigeto Furukawa and Sho Otsuka are employed by a commercial company (NTT Corporation). There are no patents, products in development or marketed products to declare. The authors confirm that this does not alter their adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: SO MT SF. Performed the experiments: SO MT JS ST SF. Analyzed the data: SO SF. Wrote the paper: SO SF MT.