9625616 Yang This project was submitted to the "Structural Control for Performance, Safety and Hazard Mitigation Research" competition. The research will be conducted in cooperation with experts from the Harbin University, PRC, and the objectives of the project are: to conduct both theoretical and experimental studies for the design of various passive energy dissipation systems based on control theories for seismic- and wind- excited structures; to carry out theoretical and experimental studies for the development of a new semi-active protective system, referred to as the semi- active hydraulic momentum damper system (SAHMDS); and to install and test a passive hydraulic momentum damper system (HMDS) in a full scale building in South West China. The first two tasks will be carried out mainly at Irvine and the last in PRC with both groups working together. The benefit of this arrangement is that during the last decade some passive control systems for seismically excited civil structures have been installed and studies by Chinese experts who can share their experiences with the American counterpart. These systems will be tested for seismic and wind hazards mitigation. ***