  The aim of this paper is a short survey of models and methods that developed
by the authors. These models and methods are used to optimize general networks
with nonlinear non-convex restrictions and objectives possessing mixed
continuous-discrete optimization variables. There are discussed the problem
formulations and solution methods for simulation, optimization, sensitivity and
stability analysis for flow with nonlinear potential in general networks. These
problems and the developed methods and programs have industrial application
e.g. by gas networks.
