This book constitutes the refereed proceedings of the 12th International Workshop on Multi-Agent-Based Simulation, MABS 2011, held in Taipei, Taiwan, in May 2011. The 10 revised selected and extended papers presented were carefully reviewed and selected from 21 submissions. The topics covered are MABS in scientometrics; MABS in politics, transit and policy; pedestrian, crowds and large scale MABS; and MABS modeling.

This book constitutes the thoroughly refereed post-conference proceedings of the First International Workshop on Citizen Sensor Networks, CitiSens 2012, in Montpellier, France, on August 27, 2012. The 7 revised full papers presented together with 1 keynote lectures were carefully reviewed and selected from 16 submissions. The accepted papers deal with topics like crowdsourcing, smart cities, multi-agent systems, privacy in social networks, data anonymity or smart sensors.