Silencing equipment is provided for an air-cooling assembly in a large off-road vehicle having wheels, traction motors for the wheels that operate in a motoring mode to propel the vehicle and a power generating dynamic braking mode, resistor grids for dissipating the dynamic braking power, and a blower for moving cooling air past the grids to cool them. A base plate is provided which is supported for sliding movement along the ground and which includes a plurality of seed apertures formed therein. The controller operates as to measure powers of an original receiving signal, the first signal and the second signal, and controls the first and second signal adjusting units. A storage management module may cause each piece of confidential information to be stored at a different, non-contiguous storage location.