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augusti 24, 2003
Simulering av "Vågen", trafikfenomen och Crowd Dynamics
Dirk Helbing är en av de som forskat kring panik (se min anteckning Applåder och panik härförleden).
Helbing har även forskat kring andra liknande fenomen, såsom Mexican Wave ("Vågen"). Läs gärna Nature-artikeln Mexican waves in an excitable medium (PDF) eller kika på simuleringar som finns på sajten. Trafiksimuleringar: Microsimulation of road traffic with a time-continuous model för exempel (laddar en Java-applet direkt). Källkoden finns att ladda ner (långt ner i högerspalten). Gångtrafikanter i en korsning: Pedestrians Interacting at a Crossing.
Se även den relaterade sajten Crowd Dynamics Limited som bland annat innehåller avhandlingen Crowd Dynamics av G. Keith Still.
Abstract:
Crowd dynamics are complex. This thesis examines the nature of the crowd and its dynamics with specific reference to the issues of crowd safety. A model (Legion) was developed that simulates the crowd as an emergent phenomenon using simulated annealing and mobile cellular automata. We outline the elements of that model based on the interaction of four parameters: Objective, Motility, Constraint and Assimilation. The model treats every entity as an individual and it can simulate how people read and react to their environment in a variety of conditions, this allows the user to study a wide range of crowd dynamics in different geometries and highlights the interactions of the crowd with its environment. We demonstrate that the model runs in polynomial time and can be used to assess the limits of crowd safety during normal and emergency egress.
Over the last 10 years there have been many incidents of crowd related disasters. We outline deficiencies in the existing guidelines relating to crowds and, by comparison and contrast with the model, we highlight specific areas where the guides may be improved. We demonstrate that the model is capable of reproducing crowd dynamics without additional parameters thus satisfying Occam’s Razor.
We propose an alternative approach to assessing the dynamics of the crowd through the use of the simulation and analysis of least effort behaviour. The model is tested against known crowd dynamics from field studies, including Wembley Stadium, Balham Station and the Hong Kong Jockey club. Finally we test the model in a variety of applications where crowd related incidents warrant structural alterations at client sites. We demonstrate that the model explains the variance in a variety of field measurements, that it is robust and that it can be applied to future designs where safety and crowd comfort are criteria for design and cost savings.
Posted by hakank at augusti 24, 2003 11:29 EM Posted to Dynamiska system | Komplexitet/emergens