Complexes

Gershenson, C. (2009). Book Review: "Reinventing the Sacred: A New View of Science, Reason, and Religion". Stuart A. Kauffman. Artificial Life 15 ( 4 ):485-487 Excerpts : One of the main goals of this book is to demonstrate the inadequacy of reductionism in contemporary science. It does not negate its explanatory and predictive powers. It notes its limits, exploring several phenomena that are not predictable due to their complex nature. Thus, Kauffman argues, a shift in science is required if we want to understand these complex phenomena. (...) People might disagree with the answers that Kauffman puts forward. However, in my opinion the greatest contribution of this book, as with Platoʼs works, lies in the questions asked. It points out clearly which problems are currently relevant for science and society, even those that people are not aware of. Different tentative or partial solutions can be debated. However, the most difficult part is to start the discussion, and that i...

Carlos Gershenson and David A. Rosenblueth, "Modeling self-organizing traffic lights with elementary cellular automata", C3 Report No. 2009.06. Abstract : There have been several highway traffic models proposed based on cellular automata. The simplest one is elementary cellular automaton rule 184. We extend this model to city traffic with cellular automata coupled at intersections using only rules 184, 252, and 136. The simplicity of the model offers a clear understanding of the main properties of city traffic and its phase transitions. We use the proposed model to compare two methods for coordinating traffic lights: a green-wave method that tries to optimize phases according to expected flows and a self-organizing method that adapts to the current traffic conditions. The self-organizing method delivers considerable improvements over the green-wave method. For low densities, the self-organizing method promotes the formation and coordination of platoons that flow freel...