Artículos con la etiqueta ‘adaptación y auto-organización’

The hypothesis of urban scaling: formalization, implications and challenges

Por • 29 ene, 2013 • Category: sociologia

There is strong expectation that cities, across time, culture and level of development, share much in common in terms of their form and function. Recently, attempts to formalize mathematically these expectations have led to the hypothesis of urban scaling, namely that certain properties of all cities change, on average, with their size in predictable scale-invariant ways. The emergence of these scaling relations depends on a few general properties of cities as social networks, co-located in space and time, that conceivably apply to a wide range of human settlements. Here, we discuss the present evidence for the hypothesis of urban scaling, some of the methodological issues dealing with proxy measurements and units of analysis and place these findings in the context of other theories of cities and urban systems. We show that a large body of evidence about the scaling properties of cities indicates, in analogy to other complex systems, that they cannot be treated as extensive systems and discuss the consequences of these results for an emerging statistical theory of cities.

Evolutionary dynamics of group interactions on structured populations: A review

Por • 13 ene, 2013 • Category: sociologia

Interactions among living organisms, from bacteria colonies to human societies, are inherently more complex than interactions among particles and nonliving matter. Group interactions are a particularly important and widespread class, representative of which is the public goods game. In addition, methods of statistical physics have proven valuable for studying pattern formation, equilibrium selection, and self-organisation in evolutionary games. Here we review recent advances in the study of evolutionary dynamics of group interactions on structured populations, including lattices, complex networks and coevolutionary models. We also compare these results with those obtained on well-mixed populations. The review particularly highlights that the study of the dynamics of group interactions, like several other important equilibrium and non-equilibrium dynamical processes in biological, economical and social sciences, benefits from the synergy between statistical physics, network science and evolutionary game theory.

Risk Mathematics and Quantum Games on Quantum Risk Structures – A Nuclear War Scenario Game

Por • 1 dic, 2012 • Category: sociologia

Quantum game theory is combined with risk mathematics’ formalism to provide an approach to evolutionary scenario analysis. The formalism is addressed in its general form and is then applied to an extreme risks modelling case, to model a coevolving dynamical web of systemic situations representing the evolution of the regional tensions between two countries with nuclear weapons. The model’s results are addressed regarding the potential for regional nuclear conflict to take place, and how evolutionary scenario analysis may contribute to nuclear war threat assessment and dynamical risk analysis. A final discussion is provided in what regards risk mathematics based on the evolutionary approach to risk assessement resulting from the combination of quantum game theory, morphic web representations and scenario analysis.

Dynamical Diagnosis and Solutions for Resilient Natural and Social Systems

Por • 12 nov, 2012 • Category: Opinion

The concept of resilience embodies the quest towards the ability to sustain shocks, to suffer from these shocks as little as possible, for the shortest time possible, and to recover with the full functionalities that existed before the perturbation. We propose an operation definition of resilience, seeing it as a measure of stress that is complementary to the risk measures. Emphasis is put on the distinction between stressors (the forces acting on the system) and stress (the internal reaction of the system to the stressors). This allows us to elaborate a classification of stress measures and of the possible responses to stressors.