A debarking apparatus includes a cutting body having a cutting surface and a first projection configured to cooperate with a fastener. The configuration is used during the execution of the simulator to control the simulation process to faithfully mimic the behavior of a variety of platforms. The receiver estimates the channel state of the received signal, selects a transmission scheme according to a channel state corresponding to the channel state estimation result, and feeds back to the transmitter transmission scheme information indicating the selected transmission scheme. The shroud defines a plurality of perforations arranged as first and second axial perforation sets, and a sleeve is arranged therein and defines one or more piston guides that align one or more pistons with either the first or second axial perforation sets, depending on the amount of cuttings and debris.