The vibration device 24, wherein a change in the direction of the combined vibration force corresponds to {HEAD ~ a change} in {TAIL ~ the direction} of a simulated motion in the computer simulation 
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The vibration device 24 , wherein a change in the direction of the combined vibration force corresponds to { HEAD ~ a change } in { TAIL ~ the direction } of a simulated motion in the computer simulation
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH