Barabási, Albert-László
(Center of Complex Networks Research, Northeastern
University and Division of Network Medicine, Harvard University)
Taming
Complexity: Controlling Networks
The ultimate proof of our understanding of biological or technological
systems is reflected in our ability to control them. While control theory
offers mathematical tools to steer engineered and natural systems towards a
desired state, we lack a framework to control complex self-organized systems.
Here we explore the controllability of an arbitrary complex network,
identifying the set of driver nodes whose time-dependent control can guide the
system’s entire dynamics. We apply these tools to several real networks,
finding that the number of driver nodes is determined mainly by the network’s
degree distribution. We show that sparse inhomogeneous networks, which tend to
be observed in most real systems, are the most difficult to control, but dense
and homogeneous networks can be controlled via a few driver nodes. Overall
issues related to control open a series of new fundamental questions pertaining
to our understanding of complex systems.
Date: Oct. 7, Tuesday 4:15pm
Place: BME, Main Building „K”, 1st Floor, Room 50