How can i get my device back now in operating system? Which is lost forever once i executed my command

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http://stackoverflow.com – I have a USB camera connected i needed to reset it or power off and power on, because it get lost often from /dev/video0 or 1. After trying this following code, it seems to be working for my goal. it powers off the usb device correctly and then powers on correctly. Everything seems fine except the big problem now faced, the moment i rebooted my system, now using lsusb i do not see my usb device any more. (when i try with another PC, same OS or different OS, the device works perfectly only in this PC its completely dead since i ran my following code) Can anyone explain why it happened and (HowTos)