Chokkou shinpuku henchou o shiyoushita dijitaru rikujou idou tsuushin houshiki no densou hinshitsu kaizen ni kansuru kenkyuu

Dijitaru idou tsuushin ni okeru kousoku kouhinshitsu densou ni kansuru kenkyuu

Dijitaru idou tsuushin keitaikiyou soujushin kairo no kenkyuu