8,114 research outputs found
Community structures and role detection in music networks
We analyze the existence of community structures in two different social
networks obtained from similarity and collaborative features between musical
artists. Our analysis reveals some characteristic organizational patterns and
provides information about the driving forces behind the growth of the
networks. In the similarity network, we find a strong correlation between
clusters of artists and musical genres. On the other hand, the collaboration
network shows two different kinds of communities: rather small structures
related to music bands and geographic zones, and much bigger communities built
upon collaborative clusters with a high number of participants related through
the period the artists were active. Finally, we detect the leading artists
inside their corresponding communities and analyze their roles in the network
by looking at a few topological properties of the nodes.Comment: 14 pages 7 figure
Thorpe method applied to planetary boundary layer data
Turbulence affects the dynamics of atmospheric processes by enhancing the transport of mass, heat, humidity and pollutants. The global objective of our work is to analyze some direct turbulent descriptors which reflect the mixing
processes in the atmospheric boundary layer (ABL). In this paper we present results related to the Thorpe displacements dT , the maximum Thorpe displacement (dT )max and the Thorpe scale LT , the Ozmidov scale and their time evolution in the ABL during a day cycle. A tethered balloon was used to obtain vertical profiles of the atmospheric physical magnitudes up to 1000m. We discuss the vertical
and horizontal variability and how different descriptors are related to atmospheric mixing
Interplay of magnetic and structural transitions in Fe-based pnictide superconductors
The interplay between the structural and magnetic phase transitions occurring
in the Fe-based pnictide superconductors is studied within a Ginzburg-Landau
approach. We show that the magnetoelastic coupling between the corresponding
order parameters is behind the salient features observed in the phase diagram
of these systems. This naturally explains the coincidence of transition
temperatures observed in some cases as well as the character (first or
second-order) of the transitions. We also show that magnetoelastic coupling is
the key ingredient determining the collinearity of the magnetic ordering, and
we propose an experimental criterion to distinguish between a pure elastic from
a spin-nematic-driven structural transition.Comment: 5 pages, 3 figures. v2: Fig. 1 improved, references added
The contribution of 211 particles to the mechanical reinforcement mechanism of 123 superconducting single domains
Hardness and fracture toughness of Dy-123 single-domains were studied by
Vickers micro-indentation. A significant anisotropy of the mechanical
properties was observed. Hardness tests give higher values when performed in
(001) planes rather than in planes parallel to the c-axis. Moreover cracks
pattern around the indentation follows preferential orientation in planes
parallel to the c-axis whereas a classical ''four-cracks'' pattern is observed
in the (001) planes. It has been possible to show the crucial role played by
the 211-particles in the deviating mechanism of cracks and the relevance of the
211-particle distribution high homogeneity in the material.Comment: 14 pages, including 5 figures and 1 Table. submitted to Supercond.
Sci. Techno
Magnetotransport in the Kondo model with ferromagnetic exchange interaction
We consider the transport properties in an applied magnetic field of the spin
S=1/2 Kondo model with ferromagnetic exchange coupling to electronic
reservoirs, a description relevant for the strong coupling limit of
underscreened spin S=1 Kondo impurities. Because the ferromagnetic Kondo
interaction is marginally irrelevant, perturbative methods should prove
accurate down to low energies. For the purpose of this study, we use a
combination of Majorana diagrammatic theory with Density Matrix Numerical
Renormalization Group simulations. In the standard case of antiferromagnetic
Kondo exchange, we first show that our technique recovers previously obtained
results for the T-matrix and spin relaxation at weak coupling (above the Kondo
temperature). Considering then the ferromagnetic case, we demonstrate how the
low-energy Kondo anomaly splits for arbitrary small values of the Zeeman
energy, in contrast to fully screened Kondo impurities near the strong coupling
Fermi liquid fixed point, and in agreement with recent experimental findings
for spin S=1 molecular quantum dots.Comment: 14 pages, 13 figures, minor changes in V
The influence of image interactivity upon user engagement when using mobile touch screens
Touch screens are a key component of consumer mobile devices such as smartphones and tablets, as well as an increasingly common self-service component of information retrieval on fixed screens and mobile devices in-store. The ubiquity of touch screens in daily life increases consumer accessibility and extended use for shopping, whilst software innovations have increased the functionality of touch screens, for example the extent to which images respond to fingertip control. This study examines how users engage with interactive visual rotation and tactile simulation features while browsing fashion clothing products on touch screen devices and thus contributes to retail touch screen research that previously focused on in-store kiosks and window displays. Findings show that three dimensions of user engagement (endurability, novelty and felt involvement) are positively influenced by both forms of manipulation. In order to examine the extent to which touch screen user engagement varies with individual preferences for an in-store experience, the paper also examines whether user engagement outcomes are mediated by an individual's need for physical touch. Findings indicate that the need for touch does not explain the variance between individuals. We conclude that touch screen technology complements the physical retail environment
Exclusive electromagnetic production of strangeness on the nucleon : review of recent data in a Regge approach
In view of the numerous experimental results recently released, we provide in
this letter an update on the performance of our simple Regge model for
strangeness electroproduction on the nucleon. Without refitting any parameters,
a decent description of all measured observables and channels is achieved. We
also give predictions for spin transfer observables, recently measured at
Jefferson Lab which have high sensitivity to discriminate between different
theoretical approaches.Comment: 5 pages, 5 figure
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