A digital signal multiplexing device packetizes one or more bitstreams of digital signals to form packets and multiplexes the respective bitstreams on the packet basis to produce plural degree-one multiplexed streams which are received. The articles are sorted and conveyed on the movable body by setting the vibration trajectory of the movable body by the vibration control means such that articles having a different coefficient of friction are conveyed in different directions. Additionally, according to some variations there will be one or more descending legs that are adapted to engage and hold debris that otherwise would pass through to the plumbing and potentially clog it. The flap may have at least one layer.