30,527 research outputs found
Towards Semantic Fast-Forward and Stabilized Egocentric Videos
The emergence of low-cost personal mobiles devices and wearable cameras and
the increasing storage capacity of video-sharing websites have pushed forward a
growing interest towards first-person videos. Since most of the recorded videos
compose long-running streams with unedited content, they are tedious and
unpleasant to watch. The fast-forward state-of-the-art methods are facing
challenges of balancing the smoothness of the video and the emphasis in the
relevant frames given a speed-up rate. In this work, we present a methodology
capable of summarizing and stabilizing egocentric videos by extracting the
semantic information from the frames. This paper also describes a dataset
collection with several semantically labeled videos and introduces a new
smoothness evaluation metric for egocentric videos that is used to test our
method.Comment: Accepted for publication and presented in the First International
Workshop on Egocentric Perception, Interaction and Computing at European
Conference on Computer Vision (EPIC@ECCV) 201
Strongly coupled plasma with electric and magnetic charges
A number of theoretical and lattice results lead us to believe that
Quark-Gluon Plasma not too far from contains not only electrically
charged quasiparticles -- quarks and gluons -- but magnetically charged ones --
monopoles and dyons -- as well. Although binary systems like charge-monopole
and charge-dyon were considered in details before in both classical and quantum
settings, it is the first study of coexisting electric and magnetic particles
in many-body context. We perform Molecular Dynamics study of strongly coupled
plasmas with particles and different fraction of magnetic charges.
Correlation functions and Kubo formulae lead to such transport properties as
diffusion constant, shear viscosity and electric conductivity: we compare the
first two with empirical data from RHIC experiments as well as results from
AdS/CFT correspondence. We also study a number of collective excitations in
these systems.Comment: 2nd version, 22 pages, 32 figures: two important new figures have
been included to compare our results with RHIC experiments and AdS/CFT
results; a few new references and comments are added as wel
A (p,q) Deformation of the Universal Enveloping Superalgebra U(osp(2/2))
We investigate a two parameter quantum deformation of the universal
enveloping orthosymplectic superalgebra U(osp(2/2)) by extending the
Faddeev-Reshetikhin-Takhtajan formalism to the supersymetric case. It is shown
that possesses a non-commutative, non-cocommutative Hopf
algebra structure. All the results are expressed in the standard form using
quantum Chevalley basis.Comment: 8 pages; IC/93/41
Healthcare Price Transparency: Policy Approaches and Estimated Impacts on Spending
Healthcare price transparency discussions typically focus on increasing patients' access to information about their out-of-pocket costs, but that focus is too narrow and should include other audiences -- physicians, employers, health plans and policymakers -- each with distinct needs and uses for healthcare price information. Greater price transparency can reduce U.S. healthcare spending.For example, an estimated 18 billion over the next decade. While 40 trillionin total projected health spending over the same period. In contrast, using state all-payer claims databases to gather and report hospital-specific prices might reduce spending by an estimated $61 billion over 10 years.The effects of price transparency depend critically on the intended audience, the decision-making context and how prices are presented. And the impact of price transparency can be greatly amplified if target audiences are able and motivated to act on the information. Simply providing prices is insufficient to control spending without other shifts in healthcare financing, including changes in benefit design to make patients more sensitive to price differences among providers and alternative treatments. Other reforms that can amplify the impact of price transparency include shifting from fee-for-service payments that reward providers for volume to payment methods that put providers at risk for spending for episodes of care or defined patient populations. While price transparency alone seems unlikely to transform the healthcare system, it can play a needed role in enabling effective reforms in value-based benefit design and provider payment
First-Order Reorientation of the Flux-Line Lattice in CaAlSi
The flux line lattice in CaAlSi has been studied by small angle neutron
scattering. A well defined hexagonal flux line lattice is seen just above Hc1
in an applied field of only 54 Oe. A 30 degree reorientation of this vortex
lattice has been observed in a very low field of 200 Oe. This reorientation
transition appears to be of first-order and could be explained by non-local
effects. The magnetic field dependence of the form factor is well described by
a single penetration depth of 1496(1) angstroms and a single coherence length
of 307(1) angstroms at 2 K. At 1.5 K the penetration depth anisotropy is 2.7(1)
with the field applied perpendicular to the c axis and agrees with the
coherence length anisotropy determined from critical field measurements.Comment: 5 pages including 6 figures, to appear in Physical Review Letter
Chiral magnetic wave at finite baryon density and the electric quadrupole moment of quark-gluon plasma in heavy ion collisions
Chiral Magnetic Wave (CMW) is a gapless collective excitation of quark-gluon
plasma in the presence of external magnetic field that stems from the interplay
of Chiral Magnetic (CME) and Chiral Separation Effects (CSE); it is composed by
the waves of the electric and chiral charge densities coupled by the axial
anomaly. We consider CMW at finite baryon density and find that it induces the
electric quadrupole moment of the quark-gluon plasma produced in heavy ion
collisions: the "poles" of the produced fireball (pointing outside of the
reaction plane) acquire additional positive electric charge, and the "equator"
acquires additional negative charge. We point out that this electric quadrupole
deformation lifts the degeneracy between the elliptic flows of positive and
negative pions leading to , and estimate the magnitude
of the effect.Comment: 4 pages, 3 figure
Impurity-doped scalar fields in arbitrary dimensions
We investigate the presence of localized structures for relativistic scalar
fields coupled to impurities in arbitrary spatial dimensions. Such systems
present spatial inhomogeneity, realized through the inclusion of explicit
coordinate dependence in the Lagrangian. It is shown that, in stark contrast to
the impurity-free scenario, Derrick's argument does not present a strong
hindrance to the existence of stable solutions in this case. Bogomol'nyi
equations giving rise to global minima of the energy are found, and some of the
ensuing BPS configurations are presented.Comment: 6 pages, 1 figure. To appear in PL
Multimagnetic Monopoles
In this work we investigate the presence of magnetic monopoles that engender
multimagnetic structures, which arise from an appropriate extension of the
gauge group. The investigation is based on a modified relativistic
theory that contain several gauge and matter fields, leading to a Bogomol'nyi
bound and thus to a first order framework, from which stable multimagnetic
solutions can be constructed. We illustrate our findings with several examples
of stable magnetic monopoles with multimagnetic properties.Comment: 10 pages, 16 figures; version to appear in EPJ
Impurity-doped stable domain walls in spherically symmetric spacetimes
In this work, radially symmetric kink-like solutions in the presence of
impurities are investigated for both flat and curved spacetimes, with
geometry generated by a rotationally invariant background metric. We have
examined the constraints placed upon the model by Derrick's theorem, and found
out the Bogomol'nyi bound and equations of the symmetric restriction to this
theory. Impurity-doped versions of a model in two dimensions and a
model with logarithmic potential in a Schwarzschild background have been
explicitly worked out. The resulting configurations have been compared with
those found in the homogeneous version of the theory, so that the effect of
impurities in the form of solutions may be better appreciated. We have also
generalized to higher dimensions some of the results that had been presented in
the recent literature. These results relate to the possibility of
BPS-preserving impurities, which we have found to still exist in the spacetimes
considered in this work. We also investigate ways in which these results may be
extended in a curved background.Comment: 8 pages, 4 figures. Version to appear in EPJ
- …