1,706 research outputs found
Investigation of origin of attached Cu-Ag droplets to solid particles during high-temperature Slag/Copper/Spinel interactions
A study of the development of IFD building systems by using the Technological Trajectories Mapping Methodology
Recognizing faces prone to occlusions and common variations using optimal face subgraphs
An intuitive graph optimization face recognition approach called Harmony Search Oriented-EBGM (HSO-EBGM) inspired by the classical Elastic Bunch Graph Matching (EBGM) graphical model is proposed in this contribution. In the proposed HSO-EBGM, a recent evolutionary approach called harmony search optimization is tailored to automatically determine optimal facial landmarks. A novel notion of face subgraphs have been formulated with the aid of these automated landmarks that maximizes the similarity entailed by the subgraphs. For experimental evaluation, two sets of de facto databases (i.e., AR and Face Recognition Grand Challenge (FRGC) ver2.0) are used to validate and analyze the behavior of the proposed HSO-EBGM in terms of number of subgraphs, varying occlusion sizes, face images under controlled/ideal conditions, realistic partial occlusions, expression variations and varying illumination conditions. For a number of experiments, results justify that the HSO-EBGM shows improved recognition performance when compared to recent state-of-the-art face recognition approaches
Point Contact Spectroscopy of Superconducting Gap Anisotropy in Nickel Borocarbide Compound LuNi2B2C
Point contacts are used to investigate the anisotropy of the superconducting
energy gap in LuNi2B2C in the ab plane and along the c axis. It is shown that
the experimental curves should be described assuming that the superconducting
gap is non-uniformly distributed over the Fermi surface. The largest and the
smallest gaps have been estimated by two-gap fitting models. It is found that
the largest contribution to the point-contact conductivity in the c direction
is made by a smaller gap and, in the ab plane by a larger gap. The deviation
from the one-gap BCS model is pronounced in the temperature dependence of the
gap in both directions. The temperature range, where the deviation occurs, is
for the c direction approximately 1.5 times more than in the ab plane. The
\Gamma parameter, allowing quantitatively estimate the gap anisotropy by
one-gap fitting, in c direction is also about 1.5 times greater than in the ab
plane. Since it is impossible to describe satisfactorily such gap distribution
either by the one- or two-gap models, a continuous, dual-maxima model of gap
distribution over the Fermi surface should be used to describe
superconductivity in this material.Comment: 10 pages, 14 Figs, accepted in PR
Wetenschapstoets Defensienota ‘Sterker Nederland, Veiliger Europa': het doel heiligt de middelen? Of andersom?
Institutions, Decisions and Collective Behaviou
The Phase Transition to a Square Vortex Lattice in Type-II Superconductors with Fourfold Anisotropy
We investigate the stability of the square vortex lattice which has been
recently observed in experiments on the borocarbide family of superconductors.
Taking into account the tetragonal symmetry of these systems, we add fourfold
symmetric fourth-derivative terms to the Ginzburg-Landau(GL) free energy. At
these terms may be treated perturbatively to lowest order to locate
the transition from a distorted hexagonal to a square vortex lattice. We also
solve for this phase boundary numerically in the strongly type-II limit,
finding large corrections to the lowest-order perturbative results. We
calculate the relative fourfold anisotropy for field in the plane
to be 4.5% at the temperature, , where the transition occurs at
for field along the axis. This is to be compared to the 3.6%
obtained in the perturbative calculation. Furthermore, we find that the phase
boundary in the phase diagram has positive slope near .Comment: 15 pages including 2 figures, LaTe
Vortex lattice structures of SrRuO
The vortex lattice structures of SrRuO for the odd parity
representations of the superconducting state are examined for the magnetic
field along the crystallographic directions. Particular emphasis is placed upon
the two dimensional representation which is believed to be relevant to this
material. It is shown that when the zero-field state breaks time reversal
symmetry, there must exist two superconducting transitions when there is a
finite field along a high symmetry direction in the basal plane. Also it is
shown that a square vortex lattice is expected when the field is along the
-axis. The orientation of the square lattice with respect to the underlying
ionic lattice yields information as to which Ru 4d orbitals are relevant to the
superconducting state.Comment: 5 pages, 2 figure
Work-related upper extremity disorders: one-year follow-up in an occupational diseases registry
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