15,905 research outputs found
Pyramidal Fisher Motion for Multiview Gait Recognition
The goal of this paper is to identify individuals by analyzing their gait.
Instead of using binary silhouettes as input data (as done in many previous
works) we propose and evaluate the use of motion descriptors based on densely
sampled short-term trajectories. We take advantage of state-of-the-art people
detectors to define custom spatial configurations of the descriptors around the
target person. Thus, obtaining a pyramidal representation of the gait motion.
The local motion features (described by the Divergence-Curl-Shear descriptor)
extracted on the different spatial areas of the person are combined into a
single high-level gait descriptor by using the Fisher Vector encoding. The
proposed approach, coined Pyramidal Fisher Motion, is experimentally validated
on the recent `AVA Multiview Gait' dataset. The results show that this new
approach achieves promising results in the problem of gait recognition.Comment: Submitted to International Conference on Pattern Recognition, ICPR,
201
A first step to accelerating fingerprint matching based on deformable minutiae clustering
Fingerprint recognition is one of the most used biometric
methods for authentication. The identification of a query fingerprint requires
matching its minutiae against every minutiae of all the fingerprints
of the database. The state-of-the-art matching algorithms are costly, from
a computational point of view, and inefficient on large datasets. In this
work, we include faster methods to accelerating DMC (the most accurate
fingerprint matching algorithm based only on minutiae). In particular,
we translate into C++ the functions of the algorithm which represent the
most costly tasks of the code; we create a library with the new code and
we link the library to the original C# code using a CLR Class Library
project by means of a C++/CLI Wrapper. Our solution re-implements
critical functions, e.g., the bit population count including a fast C++
PopCount library and the use of the squared Euclidean distance for calculating
the minutiae neighborhood. The experimental results show a
significant reduction of the execution time in the optimized functions of
the matching algorithm. Finally, a novel approach to improve the matching
algorithm, considering cache memory blocking and parallel data processing,
is presented as future work.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
On a class of minimum contrast estimators for Gegenbauer random fields
The article introduces spatial long-range dependent models based on the
fractional difference operators associated with the Gegenbauer polynomials. The
results on consistency and asymptotic normality of a class of minimum contrast
estimators of long-range dependence parameters of the models are obtained. A
methodology to verify assumptions for consistency and asymptotic normality of
minimum contrast estimators is developed. Numerical results are presented to
confirm the theoretical findings.Comment: 23 pages, 8 figure
Gauge-Higgs Unification and Radiative Electroweak Symmetry Breaking in Warped Extra Dimensions
We compute the Coleman Weinberg effective potential for the Higgs field in RS
Gauge-Higgs unification scenarios based on a bulk SO(5) x U(1)_X gauge
symmetry, with gauge and fermion fields propagating in the bulk and a custodial
symmetry protecting the generation of large corrections to the T parameter and
the coupling of the Z to the bottom quark. We demonstrate that electroweak
symmetry breaking may be realized, with proper generation of the top and bottom
quark masses for the same region of bulk mass parameters that lead to good
agreement with precision electroweak data in the presence of a light Higgs. We
compute the Higgs mass and demonstrate that for the range of parameters for
which the Higgs boson has Standard Model-like properties, the Higgs mass is
naturally in a range that varies between values close to the LEP experimental
limit and about 160 GeV. This mass range may be probed at the Tevatron and at
the LHC. We analyze the KK spectrum and briefly discuss the phenomenology of
the light resonances arising in our model.Comment: 31 pages, 9 figures. Corrected typo in boundary condition for gauge
bosons and top mass equation. To appear in PR
Stripe to spot transition in a plant root hair initiation model
A generalised Schnakenberg reaction-diffusion system with source and loss
terms and a spatially dependent coefficient of the nonlinear term is studied
both numerically and analytically in two spatial dimensions. The system has
been proposed as a model of hair initiation in the epidermal cells of plant
roots. Specifically the model captures the kinetics of a small G-protein ROP,
which can occur in active and inactive forms, and whose activation is believed
to be mediated by a gradient of the plant hormone auxin. Here the model is made
more realistic with the inclusion of a transverse co-ordinate. Localised
stripe-like solutions of active ROP occur for high enough total auxin
concentration and lie on a complex bifurcation diagram of single and
multi-pulse solutions. Transverse stability computations, confirmed by
numerical simulation show that, apart from a boundary stripe, these 1D
solutions typically undergo a transverse instability into spots. The spots so
formed typically drift and undergo secondary instabilities such as spot
replication. A novel 2D numerical continuation analysis is performed that shows
the various stable hybrid spot-like states can coexist. The parameter values
studied lead to a natural singularly perturbed, so-called semi-strong
interaction regime. This scaling enables an analytical explanation of the
initial instability, by describing the dispersion relation of a certain
non-local eigenvalue problem. The analytical results are found to agree
favourably with the numerics. Possible biological implications of the results
are discussed.Comment: 28 pages, 44 figure
Star clusters and the structure of the ISM. Tunnels and wakes in giant extragalactic HII regions
Several structures have been discovered embedded in regions of recent or
ongoing star formation, which point to the importance of the interaction
between fast moving wind-blowing stars and their environment. Using
hydrodynamic simulations, we investigate the passage through the interstellar
medium of a supersonic stellar wind source, and show how it can naturally lead
to the formation of tubes, channels and swamps of globules as interfaces are
crossed. The results are in excellent agreement with observation of 30 Doradus.Comment: 12 pages + 5 figures (GIF format) - Accepted for pub. in Astrophys.
J. Letter
Two-sided asymmetric subduction; implications for tectonomagmatic and metallogenic evolution of the Lut Block, Eastern Iran
West directed subduction zones show common characteristics, such as low structural elevation, deep trench, steep slab and a
conjugate back-arc basin that are opposite to those of the east directed subduction zones. The tectonomagmatic and
metallogenic setting of the Lut Block is still a matter of debate and several hypotheses have been put forward. Despite some
authors denying the influence of the operation of Benioff planes, the majority propose that it occurred beneath the Afghan
Block, while others consider that oceanic lithosphere was dragged under the Lut Block. Cu-Au porphyry deposits seem to
occur in an island arc geotectonic setting during the middle Eocene while Mo-bearing deposits are coincident with the
crustal thickening during Oligocene. We introduce new trace element and isotope geochemical data for granitoids and
structural evidences testifying the two-sided asymmetric subduction beneath both Afghan and Lut Blocks, with different
rates of consumption of oceanic lithosphere
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