About UCHIDA KOKI
About 日油
About OGURA TOSHIYUKI
About 日油
About KAWAMURA MINORU
About ジャペックス
About TEZUKA YASUNARI
About tunneling
About blasting
About radio transmission
About wiring
About wireless power supply
About electric detonator
About in-place test
About connection
About blasting machine
About Tunneling work
About トンネル
About 無線
About 発破