Multi-Objective Optimization Design of Control Devices to Suppress Tall Buildings Vibrations against Earthquake Excitations Using Fuzzy Logic and Genetic Algorithms - Design Optimization of Active and Passive Structural Control Systems - page 215

Multi-Objective Optimization: In this meth-
od, the main purpose is to find the optimum values
of more than one objective function, which are
usually in conflict with each other in engineering
optimization problems, so that the improvement
of one of them leads to worsening the others.
Semi Active Tuned Mass Damper (STMD):
In passive TMD system, if its damping ratio or
stiffness of the spring changes with time, then it is

called a semi-active tuned mass damper (STMD).
Variation of the damping ratio or stiffness of the
system can be regulated by different methods
such as fuzzy logic.
Tuned Mass Damper (TMD): A mechanical
system including a mass block, spring, and a vis-
cous damper able to absorb the entrance energy
from the environmental hazards such as winds
and earthquake excitations.