Preface
Stefania Bandini and Giuseppe Vizzari
The contributions included in this special selection present a broad perspective on the landscape of applications of the Cellular Automata (CA) modeling approach. In fact, although CA represents a consolidated yet still very lively topic for computability theory, mathematics, physics, complexity science, the model also represents a very successful instrument supporting a variety of different practical applications.
The first paper, titled “VALANCA: A Cellular Automata Model for Simulating Snow Avalanches” by Avolio et al., presents a model for large scale simulation of dangerous surface flows of different nature, such as lava or pyroclastic flows, avalanches, or debris flows. The paper presents both the model and its application in well-documented cases to show its adequacy to support risk mitigation.
The second article by Cacciagrano et al. and titled “Uniformity in multiscale models: from Complex Automata to BioShape” introduces a multi-scale simulation model based on Complex Automata (CxA). The work discusses both the general issues related to multi-scale models, as well as the proposed approach and its practical application to the representation of the bone remodelling process at cell and tissue scales.
The article by Razakanirina et al. entitled “Multilayer Cellular Automata on a Graph Applied to the Exchanges of Cash and Goods” describes the application of a Multilayer Cellular Automata model to the representation and simulation of socio-economic processes. In particular, the authors formally introduce the model and show that the interpretation of the achieved dynamics in terms of market dynamics produce interesting results, such as spontaneous sub-market creation, emergence of a global price in each submarket, compliance with the supply-demand law and Zipfs type of wealth distribution.
The paper titled “FPGA Processor with GPS for Modelling Railway Traffic Flow” by Tsiftsis et al. presents and overall project for supporting railway traffic flow through a Field Programmable Gate Array (FPGA) including both a Global Position System (GPS) wireless communication module as well as a CA model for the simulation of railway traffic. The paper presents both the model, its hardware implementation and real case experiments for a Greek rail line.
Finally, “An Approach for Managing Heterogeneous Speed Profiles in Cellular Automata Pedestrian Models”, by Bandini et al., describes a technique that can be applied to a wide variety of CA models for pedestrians and crowd dynamics to introduce the possibility of managing heterogeneous speed profiles for pedestrians. The paper introduces the approach, which can also be applied to model stairs and ramps in the simulated scenario, then evaluates its capability to correctly generate the desired walking speeds for pedestrians in different situations.
This special issue would not have been possible without the support and collaboration of many people that helped in different ways to make it true: in particular, we want to thank all the contributing authors (also those whose contribution does not appear in this selection) and the anonymous reviewers for their kind availability and professionalism.
Stefania Bandini, University of Milano-Bicocca, Italy
Giuseppe Vizzari, University of Milano-Bicocca, Italy