To reduce vibration in a ski and a snow board.
In a board like a ski or a snow board provided with a piezoelectric damper 26, a piezoelectric sensor 90 is provided at a board body so as to deform according to the vibration or deformation of the board body. The sensor 90 generates an electric signal to be given to a control circuit 32 with the increase of deformation. The circuit 32 receives the electric signal and generates a control signal of a waveform reverse to the detected signal though an amplitude and a frequency are proportional. The control signal stiffens the damper 26 to resist against the deformation of the board to attenuate vibration. In addition, the detected signal is stored in a memory element and then down-loaded to give the profile of a skier for analyzing.
DEROCCO ANTHONY O
GLENNE BARD
STERLING SHANE M K
