About HIGUCHI KEI
About 坂田電機
About TOOMETSUKA RYOICHI
About 坂田電機
About 地盤工学会誌
About measurement system
About radio transmission
About underground propagation
About audio frequency
About attenuation characteristic
About earth filling
About fill dam
About river levee
About underground structure
About tunnel
About waste disposal facility
About mudflow deposit damage
About facility and building
About 地中無線通信
About Other radio communication
About Applied surveying,others
About 地中
About 無線通信システム
About 地盤
About 無線
About 調査