2,400 research outputs found
{MoCapDeform}: {M}onocular {3D} Human Motion Capture in Deformable Scenes
3D human motion capture from monocular RGB images respecting interactions ofa subject with complex and possibly deformable environments is a verychallenging, ill-posed and under-explored problem. Existing methods address itonly weakly and do not model possible surface deformations often occurring whenhumans interact with scene surfaces. In contrast, this paper proposesMoCapDeform, i.e., a new framework for monocular 3D human motion capture thatis the first to explicitly model non-rigid deformations of a 3D scene forimproved 3D human pose estimation and deformable environment reconstruction.MoCapDeform accepts a monocular RGB video and a 3D scene mesh aligned in thecamera space. It first localises a subject in the input monocular video alongwith dense contact labels using a new raycasting based strategy. Next, ourhuman-environment interaction constraints are leveraged to jointly optimiseglobal 3D human poses and non-rigid surface deformations. MoCapDeform achievessuperior accuracy than competing methods on several datasets, including ournewly recorded one with deforming background scenes.<br
Noise-induced macroscopic bifurcations in globally-coupled chaotic units
Large populations of globally-coupled identical maps subjected to independent
additive noise are shown to undergo qualitative changes as the features of the
stochastic process are varied. We show that for strong coupling, the collective
dynamics can be described in terms of a few effective macroscopic degrees of
freedom, whose deterministic equations of motion are systematically derived
through an order parameter expansion.Comment: Phys. Rev. Lett., accepte
Surface and bulk electronic structures of LaOFeAs studied by angle resolved photoemission spectroscopy
The electronic structure of LaOFeAs, a parent compound of iron-arsenic
superconductors, is studied by angleresolved photoemission spectroscopy. By
examining its dependence on photon energy, polarization, sodium dosing and the
counting of Fermi surface volume, both the bulk and the surface contributions
are identified. We find that a bulk band moves toward high binding energies
below structural transition, and shifts smoothly across the spin density wave
transition by about 25 meV. Our data suggest the band reconstruction may play a
crucial role in the spin density wave transition, and the structural transition
is driven by the short range magnetic order. For the surface states, both the
LaO-terminated and FeAs-terminated components are revealed. Certain small band
shifts are verified for the FeAs-terminated surface states in the spin density
wave state, which is a reflection of the bulk electronic structure
reconstruction. Moreover, sharp quasiparticle peaks quickly rise at low
temperatures, indicating of drastic reduction of the scattering rate. A kink
structure in one of the surface band is shown to be possibly related to the
electron-phonon interactions.Comment: 9 pages, 8 figure
Observation of a Highly Spin Polarized Topological Surface State in GeBiTe
Spin polarization of a topological surface state for GeBiTe, the
newly discovered three-dimensional topological insulator, has been studied by
means of the state of the art spin- and angle-resolved photoemission
spectroscopy. It has been revealed that the disorder in the crystal has a minor
effect on the surface state spin polarization and it exceeds 75% near the Dirac
point in the bulk energy gap region (180 meV). This new finding for
GeBiTe promises not only to realize a highly spin polarized surface
isolated transport but to add new functionality to its thermoelectric and
thermomagnetic properties.Comment: 5 pages, 4 figure
Design and User Satisfaction of Interactive Maps for Visually Impaired People
Multimodal interactive maps are a solution for presenting spatial information
to visually impaired people. In this paper, we present an interactive
multimodal map prototype that is based on a tactile paper map, a multi-touch
screen and audio output. We first describe the different steps for designing an
interactive map: drawing and printing the tactile paper map, choice of
multi-touch technology, interaction technologies and the software architecture.
Then we describe the method used to assess user satisfaction. We provide data
showing that an interactive map - although based on a unique, elementary,
double tap interaction - has been met with a high level of user satisfaction.
Interestingly, satisfaction is independent of a user's age, previous visual
experience or Braille experience. This prototype will be used as a platform to
design advanced interactions for spatial learning
An Isotopic Fingerprint of Electron-Phonon Coupling in High-Tc Cuprates
Angle-resolved photoemission spectroscopy with low-energy tunable photons
along the nodal direction of oxygen isotope substituted Bi2Sr2CaCu2O8+delta
reveals a distinct oxygen isotope shift near the electron-boson coupling "kink"
in the electronic dispersion. The magnitude (a few meV) and direction of the
kink shift are as expected due to the measured isotopic shift of phonon
frequency, which are also in agreement with theoretical expectations. This
demonstrates the participation of the phonons as dominant players, as well as
pinpointing the most relevant of the phonon branches.Comment: 5 pages, 3 figure
Electron-phonon vertex in the two-dimensional one-band Hubbard model
Using quantum Monte Carlo techniques, we study the effects of electronic
correlations on the effective electron-phonon (el-ph) coupling in a
two-dimensional one-band Hubbard model. We consider a momentum-independent bare
ionic el-ph coupling. In the weak- and intermediate-correlation regimes, we
find that the on-site Coulomb interaction acts to effectively suppress the
ionic el-ph coupling at all electron- and phonon- momenta. In this regime, our
numerical simulations are in good agreement with the results of perturbation
theory to order . However, entering the strong-correlation regime, we find
that the forward scattering process stops decreasing and begins to
substantially increase as a function of , leading to an effective el-ph
coupling which is peaked in the forward direction. Whereas at weak and
intermediate Coulomb interactions, screening is the dominant correlation effect
suppressing the el-ph coupling, at larger values irreducible vertex
corrections become more important and give rise to this increase. These vertex
corrections depend crucially on the renormalized electronic structure of the
strongly correlated system.Comment: 5 pages, 4 eps-figures, minor change
Corrosion Behaviors Studied in Self-Assembled Processes of Alkanethiol Monolayers on Polycrystalline Gold Substrates
Abstract. In this paper, the corrosion phenomenon occurred on the polycrystalline gold substrates has been for the first time observed by in situ quartz crystal microbalance (QCM) method for adsorption of alkanethiol monolayers, which may be attributed to thiol-induced dissolution of gold during the adsorption process in the presence of oxygen. It is evident from the image of many corrosive defects or holes produced on the surface of gold grains by using atomic force microscopy (AFM). The kinetic equation on corrosion rate of gold dissolved in the organothiol solution has been obtained. The gold corrosion rate at fast stage can be estimated to be 9.2 × 10 11 Au atoms cm -2 s -1
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