85 research outputs found
Frequency-based brain networks: From a multiplex framework to a full multilayer description
We explore how to study dynamical interactions between brain regions using
functional multilayer networks whose layers represent the different frequency
bands at which a brain operates. Specifically, we investigate the consequences
of considering the brain as a multilayer network in which all brain regions can
interact with each other at different frequency bands, instead of as a
multiplex network, in which interactions between different frequency bands are
only allowed within each brain region and not between them. We study the second
smallest eigenvalue of the combinatorial supra-Laplacian matrix of the
multilayer network in detail, and we thereby show that the heterogeneity of
interlayer edges and, especially, the fraction of missing edges crucially
modify the spectral properties of the multilayer network. We illustrate our
results with both synthetic network models and real data sets obtained from
resting state magnetoencephalography. Our work demonstrates an important issue
in the construction of frequency-based multilayer brain networks.Comment: 13 pages, 8 figure
Beware of the Small-World neuroscientist!
The SW has undeniably been one of the most popular network descriptors in the
neuroscience literature. Two main reasons for its lasting popularity are its
apparent ease of computation and the intuitions it is thought to provide on how
networked systems operate. Over the last few years, some pitfalls of the SW
construct and, more generally, of network summary measures, have widely been
acknowledged
The Topology of Music Recommendation Networks
We study the topology of several music recommendation networks, which rise
from relationships between artist, co-occurrence of songs in playlists or
experts' recommendation. The analysis uncovers the emergence of complex network
phenomena in this kind of recommendation networks, built considering artists as
nodes and their resemblance as links. We observe structural properties that
provide some hints on navigation and possible optimizations on the design of
music recommendation systems. Finally, the analysis derived from existing music
knowledge sources provides a deeper understanding of the human music similarity
perceptions.Comment: 15 pages, 3 figure
Taming out-of-equilibrium dynamics on interconnected networks
A wide variety of social, biological or technological systems can be described as processes taking place on networked structures in continuous interaction with other networks. We propose here a new methodology to describe, anticipate and manage, in real time, the out-of-equilibrium dynamics of processes that evolve on interconnected networks. This goal is achieved through the full analytical treatment of the phenomenology and its reduction to a two-dimensional flux diagram, allowing us to predict at every time step the dynamical consequences of modifying the links between the different ensembles. Our results are consistent with real data and the methodology can be translated to clustered networks and/or interconnected networks of any size, topology or origin, from the struggle for knowledge on innovation structures to international economic relations or disease spreading on social groups.Ministerio de EconomĂa y Competitividad; Comunidad de Madri
Bistable phase control via rocking in a nonlinear electronic oscillator
We experimentally demonstrate the effective rocking of a nonlinear electronic
circuit operating in a periodic regime. Namely, we show that driving a Chua
circuit with a periodic signal, whose phase alternates (also periodically) in
time, we lock the oscillation frequency of the circuit to that of the driving
signal, and its phase to one of two possible values shifted by pi, and lying
between the alternating phases of the input signal. In this way, we show that a
rocked nonlinear oscillator displays phase bistability. We interpret the
experimental results via a theoretical analysis of rocking on a simple
oscillator model, based on a normal form description (complex Landau equation)
of the rocked Hopf bifurcationComment: 7 pages, 10 figure
The Social Network of Contemporary Popular Musicians
In this paper we analyze two social network datasets of contemporary
musicians constructed from allmusic.com (AMG), a music and artists' information
database: one is the collaboration network in which two musicians are connected
if they have performed in or produced an album together, and the other is the
similarity network in which they are connected if they where musically similar
according to music experts. We find that, while both networks exhibit typical
features of social networks such as high transitivity, several key network
features, such as degree as well as betweenness distributions suggest
fundamental differences in music collaborations and music similarity networks
are created.Comment: 7 pages, 2 figure
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