Distributed Robust Stability Analysis of Interconnected Uncertain   Systems
  This paper considers robust stability analysis of a large network of interconnected uncertain systems. To avoid analyzing the entire network as a single large, lumped system, we model the network interconnections with integral quadratic constraints. This approach yields a sparse linear matrix inequality which can be decomposed into a set of smaller, coupled linear matrix inequalities. This allows us to solve the analysis problem efficiently and in a distributed manner. We also show that the decomposed problem is equivalent to the original robustness analysis problem, and hence our method does not introduce additional conservativeness. 
Martin S. Andersen, Anders Hansson, Sina Khoshfetrat Pakazad, Anders   Rantzer
math.OC