Researchers have studied many methods of using active and passive control devices for absorbing vibratory energy. Active devices, while providing significant reductions in structural motion, typically require large (and often multiply-redundant) power sources, and thereby raise concerns about stability. Passive devices are fixed and cannot be modified based on information of excitation or structural response. Semiactive devices on the other hand can provide significant vibration reductions comparable to those of active devices but with substantially reduced power requirements and in a stable...