55 research outputs found
A semi-automatic parallelization tool for Java based on fork-join synchronization patterns
Because of the increasing availability of multi-core machines, clusters, Grids, and combinations of these environments, there is now plenty of computational power available for executing compute intensive applications. However, because of the overwhelming and rapid advances in distributed and parallel hardware and environments, today?s programmers are not fully prepared to exploit distribution and parallelism. In this sense, the Java language has helped in handling the heterogeneity of such environments, but there is a lack of facilities and tools to easily distributing and parallelizing applications. One solution to mitigate this problem and make some progress towards producing general tools seems to be the synthesis of semi-automatic parallelism and Parallelism as a Concern (PaaC), which allows parallelizing applications along with as little modifications on sequential codes as possible. In this paper, we discuss a new approach that aims at overcoming the drawbacks of current Java-based parallel and distributed development tools, which precisely exploit these new conceptsFil: Hirsch, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Instituto Superior de Ingenieria del Software; Argentina;Fil: Zunino, Alejandro. Consejo Nacional de Invest.cientif.y Tecnicas. Ctro Cientifico Tecnologico Conicet - Tandil. Instituto Superior de Ingenieria del Software;Fil: Mateos Diaz, Cristian Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Instituto Superior de Ingenieria del Software
Novelty Improves the Formation and Persistence of Memory in a Naturalistic School Scenario
One of the top challenges in education and neuroscience consists in translating laboratory results into strategies to improve learning and memory in teaching environments. In that sense, during the last two decades, researchers have discovered specific temporal windows around learning, during which the intervention with some experiences induces modulatory effects on the formation and/or persistence of memory. Based on these results, the aim of the present study was to design a specific strategy to improve the memory of students in a high-school scenario, by assessing the effect of a novel situation experienced close to learning. We found that the long-term memory about a geometrical figure was more precise in the group of students that faced a novel situation 1 h before or after learning the figure than the control group of students who did not face the novelty. This enhancement was probably triggered by processes acting on memory formation mechanisms that remained evident 45 days after learning, indicating that the improvement was sustained over time. In addition, our results showed that novelty no longer improved the memory if it was experienced 4 h before or after learning. However, far beyond this window of efficacy, when it was faced around 10 h after learning, the novel experience improved the memory persistence tested 7 days later. In summary, our findings characterized different temporal windows of the effectiveness of novelty acting on memory processing, providing a simple and inexpensive strategy that could be used to improve memory formation and persistence in high-school students.Fil: Ramírez Butavand, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Hirsch, Ian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Tomaiuolo, Micol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Moncada, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Viola, Haydée. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Ballarini, Fabricio Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentin
A Simulation-based Performance Evaluation of Heuristics for Dew Computing
The evolution of smartphones allows the continuous exploitation of computing resources. This increasingly applies also to distributed environments as exemplified through utilization of network router loads in edge computing and fog computing. Combining cloud computing and mobile smart devices in dew computing contexts enables new techniques for resource utilization, data collection and data processing. However, new challenges regarding job scheduling arise. Smartphones may be used in ad-hoc networks in this context, but their heterogeneity and energy usage must be considered. We propose novel heuristics for performance measuring of distributed computing systems integrated with mobile devices and compare them with previous heuristics in a simulation environment. Our results show an overall improvement in job completion and load balancing metrics compared to previous approaches. They highlight the usefulness of pursuing this research stream for aiming at industrial implementation and evaluation
Tri-Bimaximal Neutrino Mixing, A4 and the Modular Symmetry
We formulate and discuss a 4-dimensional SUSY version of an A4 model for
tri-bimaximal neutrino mixing which is completely natural. We also study the
next-to-the-leading corrections and show that they are small, once the ratios
of A4 breaking VEVs to the cutoff are fixed in a specified interval. We also
point out an interesting way of presenting the A4 group starting from the
modular group. In this approach, which could be interesting in itself as an
indication on a possible origin of A4, the lagrangian basis where the symmetry
is formulated coincides with the basis where the charged leptons are diagonal.
If the same classification structure in A4 is extended from leptons to quarks,
the CKM matrix coincides with the unit matrix in leading order and a study of
non leading corrections shows that the departures from unity of the CKM matrix
are far too small to accomodate the observed mixing angles.Comment: 21 pages, 1 figure; added section on a see-saw realization; version
to appear on Nucl. Phys.
Tri-Bimaximal Lepton Mixing and Leptogenesis
In models with flavour symmetries added to the gauge group of the Standard
Model the CP-violating asymmetry necessary for leptogenesis may be related with
low-energy parameters. A particular case of interest is when the flavour
symmetry produces exact Tri-Bimaximal lepton mixing leading to a vanishing
CP-violating asymmetry. In this paper we present a model-independent discussion
that confirms this always occurs for unflavoured leptogenesis in type I see-saw
scenarios, noting however that Tri-Bimaximal mixing does not imply a vanishing
asymmetry in general scenarios where there is interplay between type I and
other see-saws. We also consider a specific model where the exact Tri-Bimaximal
mixing is lifted by corrections that can be parametrised by a small number of
degrees of freedom and analyse in detail the existing link between low and
high-energy parameters - focusing on how the deviations from Tri-Bimaximal are
connected to the parameters governing leptogenesis.Comment: 29 pages, 6 figures; version 2: references added, minor correction
A SUSY SU(5) Grand Unified Model of Tri-Bimaximal Mixing from A4
We discuss a grand unified model based on SUSY SU(5) in extra dimensions and
on the flavour group A4xU(1) which, besides reproducing tri-bimaximal mixing
for neutrinos with the accuracy required by the data, also leads to a natural
description of the observed pattern of quark masses and mixings.Comment: 19 page
New-physics contributions to the forward-backward asymmetry in B -> K* mu+ mu-
We study the forward-backward asymmetry (AFB) and the differential branching
ratio (DBR) in B -> K* mu+ mu- in the presence of new physics (NP) with
different Lorentz structures. We consider NP contributions from vector-axial
vector (VA), scalar-pseudoscalar (SP), and tensor (T) operators, as well as
their combinations. We calculate the effects of these new Lorentz structures in
the low-q^2 and high-q^2 regions, and explain their features through analytic
approximations. We find two mechanisms that can give a significant deviation
from the standard-model predictions, in the direction indicated by the recent
measurement of AFB by the Belle experiment. They involve the addition of the
following NP operators: (i) VA, or (ii) a combination of SP and T (slightly
better than T alone). These two mechanisms can be distinguished through
measurements of DBR in B -> K* mu+ mu- and AFB in B -> K mu+ mu-.Comment: 33 pages, revtex, 9 figures. Paper originally submitted with the
wrong figures. This is corrected in the replacement. An incorrect factor of 2
found in a formula. This is corrected and figures modified. Conclusions
unchanged. Typos correcte
Proceedings of the 2nd Workshop on Flavor Symmetries and Consequences in Accelerators and Cosmology (FLASY12)
These are the proceedings of the 2nd Workshop on Flavor Symmetries and
Consequences in Accelerators and Cosmology, held 30 June 2012 - 4 July 2012,
Dortmund, Germany.Comment: Order 400 pages, several figures including the group picture v2:
corrected author list and contributio
A Simplest A4 Model for Tri-Bimaximal Neutrino Mixing
We present a see-saw model for Tri-Bimaximal mixing which is based on a
very economical flavour symmetry and field content and still possesses all the
good features of models. In particular the charged lepton mass
hierarchies are determined by the flavour symmetry itself
without invoking a Froggatt-Nielsen U(1) symmetry. Tri-Bimaximal mixing is
exact in leading order while all the mixing angles receive corrections of the
same order in next-to-the-leading approximation. As a consequence the predicted
value of is within the sensitivity of the experiments which will
take data in the near future. The light neutrino spectrum, typical of
see-saw models, with its phenomenological implications, also including
leptoproduction, is studied in detail.Comment: 20 pages, 2 figure
Lepton Flavour Violation in Models with A4 Flavour Symmetry
We analyze lepton flavour violating transitions, leptonic magnetic dipole
moments (MDMs) and electric dipole moments (EDMs) in a class of models
characterized by the flavour symmetry A4 x Z3 x U(1)_{FN}, whose choice is
motivated by the approximate tri-bimaximal mixing observed in neutrino
oscillations. We construct the relevant low-energy effective Lagrangian where
these effects are dominated by dimension six operators, suppressed by the scale
M of new physics. All the flavour breaking effects are universally described by
the vacuum expectation values of a set of spurions. We separately analyze
both a supersymmetric and a general case. While the observed discrepancy delta
a_mu in the anomalous MDM of the muon suggests M of order of a few TeV, several
data require M above 10 TeV, in particular the limit on EDM of the electron. In
the general case also the present limit on BR(mu -> e gamma) requires M >10
TeV, at least. The branching ratios for mu -> e gamma, tau -> mu gamma and tau
-> e gamma are all expected to be of the same order. In the supersymmetric case
the constraint from mu -> e gamma is softened and it can be satisfied by a
smaller scale M. In this case both the observed delta a_mu and the current
bound on BR(mu -> e gamma) can be satisfied, at the price of a rather small
value for ||, of the order of a few percents, that reflects on a similar
value for theta_{13}.Comment: 29 pages, 1 figur
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