8,228 research outputs found
Innovations in the development of degree thesis of a informatics career. Cohorts 2003-2007.
Trabajo Final de Aplicación es una asignatura de las carreras Licenciatura en Sistemas y Licenciatura en Sistemas de Información (FACENA – UNNE). Tiene por objetivo general, completar la formación académica y profesional de los alumnos, a fin de fomentar la integración y empleo de los conocimientos adquiridos para la resolución de problemas. En este trabajo se sintetizan las innovaciones de la cátedra en las cohortes 2003 a 2007. La primera sección ilustra el contexto, la segunda resume la metodología aplicada. En la tercera se sintetizan los resultados alcanzados. Finalmente se enuncian las conclusiones y futuras líneas de trabajo.Trabajo Final de Aplicación is a subject of Licenciatura en Sistemas and
Licenciatura en Sistemas de Información career (FACENA - UNNE).
Its overall goal, completing the academic and professional training of students, to foster the
integration and use of knowledge acquired in order to guide the problemsolving.
This paper summarizes the implemented innovations between the years 2003 to
2007. The first section illustrates the context. The second section summarizes the
methodology and the third section the results achieved. Finally, some conclusions
and future lines of work are exposed
Gravitational waves from eccentric intermediate mass binary black hole mergers
Owing to the difficulty of direct observation, mergers of intermediate-mass black hole binaries are relatively less understood compared to stellar-mass binaries; however, the gravitational waves from their last few orbits and ringdown fall in the band of ground-based detectors. Because the typical source is expected to circularize prior to entering LIGO or VIRGO's range, inspiral searches concentrate on circularized binaries. It is possible that events will be missed if there are sources with residual eccentricity. We study the variation of the signal to noise present in the dominant mode of the eccentric evolutions as a function of mass and eccentricity and also the relative contribution of the signal in the various spherical harmonic modes. The energy radiated in gravitational waves increases with eccentricity until the eccentricity becomes too high, leading to plunging trajectories, at which point the energy radiated decreases. This enhancement of the energy for initial eccentricities near the transition value translates into larger signal-to-noise ratios. Consequently despite the anticipated loss in the signal-to-noise ratio due to the use of quasi-circular detection templates, some eccentric signals potentially may be seen farther out than others
Characterizing quantum chaoticity of kicked spin chains
Quantum many-body systems are commonly considered as quantum chaotic if their
spectral statistics, such as the level spacing distribution, agree with those
of random matrix theory. Using the example of the kicked Ising chain we
demonstrate that even if both level spacing distribution and eigenvector
statistics agree well with random matrix predictions, the entanglement entropy
deviates from the expected Page curve. To explain this observation we propose a
new measure of the effective spin interactions and obtain the corresponding
random matrix result. By this the deviations of the entanglement entropy can be
attributed to significantly different behavior of the -spin interactions
compared with RMT
Seeking for toroidal event horizons from initially stationary BH configurations
We construct and evolve non-rotating vacuum initial data with a ring
singularity, based on a simple extension of the standard Brill-Lindquist
multiple black-hole initial data, and search for event horizons with spatial
slices that are toroidal when the ring radius is sufficiently large. While
evolutions of the ring singularity are not numerically feasible for large
radii, we find some evidence, based on configurations of multiple BHs arranged
in a ring, that this configuration leads to singular limit where the horizon
width has zero size, possibly indicating the presence of a naked singularity,
when the radius of the ring is sufficiently large. This is in agreement with
previous studies that have found that there is no apparent horizon surrounding
the ring singularity when the ring's radius is larger than about twice its
mass.Comment: 24 pages, 14 figure
Effect of rolling on dissipation in fault gouges
Sliding and rolling are two outstanding deformation modes in granular media. The first one induces frictional dissipation whereas the latter one involves deformation with negligible resistance. Using numerical simulations on two-dimensional shear cells, we investigate the effect of the grain rotation on the energy dissipation and the strength of granular materials under quasistatic shear deformation. Rolling and sliding are quantified in terms of the so-called Cosserat rotations. The observed spontaneous formation of vorticity cells and clusters of rotating bearings may provide an explanation for the long standing heat flow paradox of earthquake dynamics
Superdiffusion of massive particles induced by multi-scale velocity fields
We study drag-induced diffusion of massive particles in scale-free velocity
fields, where superdiffusive behavior emerges due to the scale-free size
distribution of the vortices of the underlying velocity field. The results show
qualitative resemblance to what is observed in fluid systems, namely the
diffusive exponent for the mean square separation of pairs of particles and the
preferential concentration of the particles, both as a function of the response
time.Comment: 5 pages, 5 figures. Accepted for publication in EP
N=2 central charge superspace and a minimal supergravity multiplet
We extend the notion of central charge superspace to the case of local
supersymmetry. Gauged central charge transformations are identified as
diffeomorphisms at the same footing as space-time diffeomorphisms and local
supersymmetry transformations. Given the general structure we then proceed to
the description of a particular vector-tensor supergravity multiplet of 24+24
components, identified by means of rather radical constraints
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