Linux On My Samsung

When I add the ppa into my system. All goes well. The error will come up when i do 'sudo apt-get update'. It shows

W: Failed to fetch http://ppa.launchpad.net/voria/ppa/ubuntu/dists/vivid/main/binary-amd64/Packages 404 Not Found

W: Failed to fetch http://ppa.launchpad.net/voria/ppa/ubuntu/dists ...