In a recent study, Ohira and Sawatari presented a simple model of computer network traffic dynamics. These authors showed that a phase transition point is present separating the low-traffic phase with no congestion from the congestion phase as the packet creation rate increases. We further...

In a recent paper, we analysed the dynamics of traffic flow in a simple, square lattice architecture. It was shown that a phase transition takes place between a free and a congested phase. The transition point was shown to exhibit optimal information transfer and wide fluctuations in time, with...

Transport networks are a key component of human and natural societies that enable efficient communication at a low cost. Here, we study the topological efficiency of the three-dimensional networks of galleries in termite nests and how spatial constraints affect the organisation of these...

A new model ecosystem of many interacting species is introduced in which the species are connected through a random matrix with a given connectivity. The model is studied both analytically and by numerical simulations. A probability distribution derived from the model is in good agreement with...

A model of biological morphogenesis is presented. The model is based on a gene network cell description and the interaction among the nearest cells. Here interactions between cells are due to diffusion-like mechanisms and also due to inductive, cell-to-cell interactions. An extensive analysis...

A new order parameter approximation to random boolean networks (RBN) is introduced, based on the concept of Boolean derivative. A statistical argument involving an annealed approximation is used, allowing to measure the order parameter in terms of the statistical properties of a random matrix....