Movers and shakers [Control Safety]

The paper mentions that man's fear of earthquakes is helping him devise a control system to mitigate their impact on buildings. The technology is classified according to three types of system passive, active and semi-active or hybrid. Passive systems are the most mature of the three, and rely simply on absorbing or dissipating someof an earthquake's energy, with no feedback between them, the building's structural elements and the ground. The systems are further divided into energy dissipaters, base isolators and tuned mass dampers.