25 research outputs found
Robustness of cultural communities in an open-ended Axelrod's model
We consider an open-ended set of cultural features in the Axelrod's model of
cultural dissemination. By replacing the features in which a high degree of
consensus is achieved by new ones, we address here an essential ingredient of
societies: the evolution of topics as a result of social dynamics and debate.
Our results show that, once cultural clusters have been formed, the
introduction of new topics into the social debate has little effect on them,
but it does have a significant influence on the cultural overlap. Along with
the Monte-Carlo simulations, we derive and numerically solve an equation for
the stationary cultural overlap based on a mean-field approach. Although the
mean-field analysis reproduces qualitatively the characteristic phase
transition of the Axelrod's model, it underestimates the cultural overlap,
highlighting the role of the local interactions in the Axelrod's dynamics, as
well as the correlations between the different cultural features.Comment: 6 pages and 5 figure
A networked voting rule for democratic representation
We introduce a general framework for exploring the problem of selecting a
committee of representatives with the aim of studying a networked voting rule
based on a decentralized large-scale platform, which can assure a strong
accountability of the elected. The results of our simulations suggest that this
algorithm-based approach is able to obtain a high representativeness for
relatively small committees, performing even better than a classical voting
rule based on a closed list of candidates. We show that a general relation
between committee size and representatives exists in the form of an inverse
square root law and that the normalized committee size approximately scales
with the inverse of the community size, allowing the scalability to very large
populations. These findings are not strongly influenced by the different
networks used to describe the individuals interactions, except for the presence
of few individuals with very high connectivity which can have a marginally
negative effect in the committee selection process.Comment: Submitted for publicatio
Analysis of a networked social algorithm for collective selection of a committee of representatives
A recent work by Hern\'andez et al. introduced a networked voting rule
supported by a trust-based social network, where indications of possible
representatives were based on individuals opinions. Individual contributions
went beyond a simple vote-counting and were based on proxy voting. These
mechanisms generated a high level of representativeness of the selected
committee, weakening the possibility of relations of patronage. By
incorporating the integrity of individuals and its perception, here we address
the question of the trustability of the resulting committee. Our results show
that this voting rule provides high representativeness for small committees
with a high level of integrity. Furthermore, the voting system displays
robustness to a strategic and untruthful application of the voting algorithm.Comment: 7 pages and 8 figures. Submitted for publication. arXiv admin note:
text overlap with arXiv:1801.0539
Testing macroecological theories in cryptocurrency market: neutral models can not describe diversity patterns and their variation
We develop an analysis of the cryptocurrency market borrowing methods and
concepts from ecology. This approach makes it possible to identify specific
diversity patterns and their variation, in close analogy with ecological
systems, and to characterize the cryptocurrency market in an effective way. At
the same time, it shows how non-biological systems can have an important role
in contrasting different ecological theories and in testing the use of neutral
models. The study of the cryptocurrencies abundance distribution and the
evolution of the community structure strongly indicates that these statistical
patterns are not consistent with neutrality. In particular, the necessity to
increase the temporal change in community composition when the number of
cryptocurrencies grows, suggests that their interactions are not necessarily
weak. The analysis of the intraspecific and interspecific interdependency
supports this fact and demonstrates the presence of a market sector influenced
by mutualistic relations. These latest findings challenge the hypothesis of
weakly interacting symmetric species, the postulate at the heart of neutral
models.Comment: 18 pages, 8 figure
Built form and cultural identity : exploring spatial information to understand different spatial cultures
The idea that urban form embodies idiosyncrasies that express cultural identities seems to be a frequent assumption in urban studies. It has to do with the contextual role of custom and institutional settings, from regional idiosyncrasies assimilated to traditional ways of building to the dichotomies of planned and unplanned cities, shaped through topdown agencies or as chance-grown arrangements. However, can local cultures leave traces in urban space? Despite its persistence in the urban imagination, the problem of how built environments might embody specific cultural identities seems yet to be fully addressed in urban morphology. In this sense, historically- and culturally-informed quantitative methods are essential for uncovering forms and patterns resulting from city organisation processes. In this paper, we look closely into that assumption and address the question of whether cities find distinct regional characteristics or take on physically specific forms under certain cultural conditions. This problem implies examining the existence of contextualised ways of shaping cities – and features that might transcend context. We do so approaching the built environment's spatial configurations as a proxy of urban culture, looking into urban form's very constituents. Unlike emphases on street networks, our approach focuses on the elementary components shaping cities' tangible spaces: buildings and how they are aggregated in cellular complexes of built form. Exploring Shannon's information theory, we introduce a measure of information and entropy to analyse the probability distribution of cellular arrangements in built form systems. We apply it to 45 cities from different regions of the world as a similarity measure to compare and cluster cities potentially consistent with specific spatial cultures. Findings suggest a classification scheme that sheds further light on what we call "the cultural hypothesis": the possibility that different cultures and regions find different ways of ordering space
Consequence of reputation in an open-ended Naming Game
We study a modified version of the Naming Game, a recently introduced model
which describes how shared vocabulary can emerge spontaneously in a population
without any central control. In particular, we introduce a new mechanism that
allows a continuous interchange with the external inventory of words. A novel
playing strategy, influenced by the hierarchical structure that individuals'
reputation defines in the community, is implemented. We analyze how these
features influence the convergence times, the cognitive efforts of the agents
and the scaling behavior in memory and time.Comment: 6 pages, 6 figure
Quasi-stationary states in low-dimensional Hamiltonian systems
We address a simple connection between results of Hamiltonian nonlinear
dynamical theory and thermostatistics. Using a properly defined dynamical
temperature in low-dimensional symplectic maps, we display and characterize
long-standing quasi-stationary states that eventually cross over to a
Boltzmann-Gibbs-like regime. As time evolves, the geometrical properties (e.g.,
fractal dimension) of the phase space change sensibly, and the duration of the
anomalous regime diverges with decreasing chaoticity. The scenario that emerges
is consistent with the nonextensive statistical mechanics one.Comment: Latex, 11 pages, 4 figure
Order parameters and for different .
<p>Data are averaged over 100 simulations when the system reaches the quasi-stationary state (, , and ).</p