. "2017-08-30" . _:vb50822089 . _:vb50822087 "Kenneth Christiansen" . "Motion Sensors Explainer" . . . _:vb50822088 . . _:vb50822089 . _:vb50822087 . _:vb50822087 . _:vb50822088 "Alexander Shalamov" . _:vb50822088 . . _:vb50822089 .