Motorization is a self-reinforcing process, which involves positive feedback. Using a simple model of bi-modal transportation system, it is shown that a transportation system may eventually be dominated by the automobile, or may equilibrate at a grossly inefficient point due to social dilemmas...

Statistical properties of the inhomogeneous version of the Olami-Feder-Christensen (OFC) model of earthquakes is investigated by numerical simulations. The spatial inhomogeneity is assumed to be dynamical. Critical features found in the original homogeneous OFC model, e.g., the Gutenberg-Richter...