3,063 research outputs found
Vision-Based Production of Personalized Video
In this paper we present a novel vision-based system for the automated production of personalised video souvenirs for visitors in leisure and cultural heritage venues. Visitors are visually identified and tracked through a camera network. The system produces a personalized DVD souvenir at the end of a visitor’s stay allowing visitors to relive their experiences. We analyze how we identify visitors by fusing facial and body features, how we track visitors, how the tracker recovers from failures due to occlusions, as well as how we annotate and compile the final product. Our experiments demonstrate the feasibility of the proposed approach
Discrete surface solitons in two-dimensional anisotropic photonic lattices
We study nonlinear surface modes in two-dimensional {\em anisotropic}
periodic photonic lattices and demonstrate that, in a sharp contrast to
one-dimensional discrete surface solitons, the mode threshold power is lower at
the surface, and two-dimensional discrete solitons can be generated easier near
the lattice corners and edges. We analyze the crossover between effectively
one- and two-dimensional regimes of the surface-mediated beam localization in
the lattice.Comment: 3 pages, 4 figure
Breaking of PT-symmetry in bounded and unbounded scattering systems
PT-symmetric scattering systems with balanced gain and loss can undergo a
symmetry-breaking transition in which the eigenvalues of the non-unitary
scattering matrix change their phase shifts from real to complex values. We
relate the PT-symmetry breaking points of such an unbounded scattering system
to those of underlying bounded systems. In particular, we show how the
PT-thresholds in the scattering matrix of the unbounded system translate into
analogous transitions in the Robin boundary conditions of the corresponding
bounded systems. Based on this relation, we argue and then confirm that the
PT-transitions in the scattering matrix are, under very general conditions,
entirely insensitive to a variable coupling strength between the bounded region
and the unbounded asymptotic region, a result that can be tested experimentally
and visualized using the concept of Smith charts.Comment: 9 pages, 6 figures (final version, including newly added connection
to the concept of "Smith charts"
Observation of two-dimensional lattice interface solitons
We report on the experimental observation of two-dimensional solitons at the
interface between square and hexagonal waveguide arrays. In addition to the
different symmetry of the lattices, the influence of a varying refractive index
modulation depth is investigated. Such variation strongly affects the
properties of surface solitons residing at different sides of the interface.Comment: 14 pages, 5 figures, to appear in Optics Letter
Use of Equivalent Hermitian Hamiltonian for -Symmetric Sinusoidal Optical Lattices
We show how the band structure and beam dynamics of non-Hermitian
-symmetric sinusoidal optical lattices can be approached from the point of
view of the equivalent Hermitian problem, obtained by an analytic continuation
in the transverse spatial variable . In this latter problem the eigenvalue
equation reduces to the Mathieu equation, whose eigenfunctions and properties
have been well studied. That being the case, the beam propagation, which
parallels the time-development of the wave-function in quantum mechanics, can
be calculated using the equivalent of the method of stationary states. We also
discuss a model potential that interpolates between a sinusoidal and periodic
square well potential, showing that some of the striking properties of the
sinusoidal potential, in particular birefringence, become much less prominent
as one goes away from the sinusoidal case.Comment: 11 pages, 8 figure
Влияние катодного смещения от стационарного потенциала поверхности на шероховатость покрытия в электролите химического никелирования
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Binocular vision enhances a rapidly evolving affordance priming effect: Behavioural and TMS evidence
Extensive research has suggested that simply viewing an object can automatically prime compatible actions for object manipulation, known as affordances. Here we explored the generation of covert motor plans afforded by real objects with precision (‘pinchable’) or whole-hand/power (‘graspable’) grip significance under different types of vision. In Experiment 1, participants viewed real object primes either monocularly or binocularly and responded to orthogonal auditory stimuli by making precision or power grips. Pinchable primes facilitated congruent precision grip responses relative to incongruent power grips, and vice versa for graspable primes, but only in the binocular vision condition. To examine the temporal evolution of the binocular affordance effect, participants in Experiment 2 always viewed the objects binocularly but made no responses, instead receiving a transcranial magnetic stimulation pulse over their primary motor cortex at three different times (150, 300, 450 ms) after prime onset. Motor evoked potentials (MEPs) recorded from a pinching muscle were selectively increased when subjects were primed with a pinchable object, whereas MEPs from a muscle associated with power grips were increased when viewing graspable stimuli. This interaction was obtained both 300 and 450 ms (but not 150 ms) after the visual onset of the prime, characterising for the first time the rapid development of binocular grip-specific affordances predicted by functional accounts of the affordance effect
Economic growth and exporting activity : an empirical analysis on Greek industry
The aim of the present paper is to locate and analyse the factors affecting firms’ economic behaviour in food products’ sector, by collecting data from a large number of firms and indicators.
A special focus concerning exporting activity took place, trying to disclose the factors that spur exports, as they are considered to be a synonym of economic growth and prosperity. Several methodological issues of exports’ valuation were opposed and some strong conclusions were underlined as regard to the necessary infrastructure that a firm should develop, in order to grow, and to establish a dynamic exporting profile.peer-reviewe
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