937 research outputs found
Alien Registration- Baltrusaitis+, Petruse (Lewiston, Androscoggin County)
https://digitalmaine.com/alien_docs/30411/thumbnail.jp
Hand2Face: Automatic Synthesis and Recognition of Hand Over Face Occlusions
A person's face discloses important information about their affective state.
Although there has been extensive research on recognition of facial
expressions, the performance of existing approaches is challenged by facial
occlusions. Facial occlusions are often treated as noise and discarded in
recognition of affective states. However, hand over face occlusions can provide
additional information for recognition of some affective states such as
curiosity, frustration and boredom. One of the reasons that this problem has
not gained attention is the lack of naturalistic occluded faces that contain
hand over face occlusions as well as other types of occlusions. Traditional
approaches for obtaining affective data are time demanding and expensive, which
limits researchers in affective computing to work on small datasets. This
limitation affects the generalizability of models and deprives researchers from
taking advantage of recent advances in deep learning that have shown great
success in many fields but require large volumes of data. In this paper, we
first introduce a novel framework for synthesizing naturalistic facial
occlusions from an initial dataset of non-occluded faces and separate images of
hands, reducing the costly process of data collection and annotation. We then
propose a model for facial occlusion type recognition to differentiate between
hand over face occlusions and other types of occlusions such as scarves, hair,
glasses and objects. Finally, we present a model to localize hand over face
occlusions and identify the occluded regions of the face.Comment: Accepted to International Conference on Affective Computing and
Intelligent Interaction (ACII), 201
Impact of atmospheric parameters on the atmospheric Cherenkov technique
Atmospheric density profiles as well as several light absorption and
scattering processes depend on geographic position and are generally
time-variable. Their impact on the atmospheric Cherenkov technique in general
(imaging or non-imaging) is investigated. Different density profiles lead to
differences in Cherenkov light density of up to 60%. Seasonal variations at
mid-latitude sites are of the order of 15-20%. The quest for improved energy
calibration of Cherenkov experiments also shows the need for improved
transmission calculations, taking all relevant processes into account and using
realistic profiles of absorbers. Simulations including the scattering
mechanisms also reveal the relevance of Rayleigh and Mie scattering for
atmospheric Cherenkov experiments. Refraction and the differences between
treating the atmosphere in plane-parallel or spherical geometry are also
investigated.Comment: 23 pages, 15 figures. Accepted by Astroparticle Physic
Optimization of the Collection Efficiency of a Hexagonal Light Collector using Quadratic and Cubic B\'ezier Curves
Reflective light collectors with hexagonal entrance and exit apertures are
frequently used in front of the focal-plane camera of a very-high-energy
gamma-ray telescope to increase the collection efficiency of atmospheric
Cherenkov photons and reduce the night-sky background entering at large
incident angles. The shape of a hexagonal light collector is usually based on
Winston's design, which is optimized for only two-dimensional optical systems.
However, it is not known whether a hexagonal Winston cone is optimal for the
real three-dimensional optical systems of gamma-ray telescopes. For the first
time we optimize the shape of a hexagonal light collector using quadratic and
cubic B\'ezier curves. We demonstrate that our optimized designs simultaneously
achieve a higher collection efficiency and background reduction rate than
traditional designs.Comment: 9 pages, 9 figure
Coarse lattice results for glueballs and hybrids
A review of new results from lattice simulations of glueballs and heavy-quark
hybrid mesons is presented.Comment: 6 pages, 4 figures, uses espcrc2.sty. Contribution to Lattice '97,
Edinburg
Limits on deeply penetrating particles in the >10^17 eV cosmic-ray flux
Journal ArticleWe report on a search for deeply penetrating particles in the > 10^17 eV cosmic-ray flux using the University of Utah Fly's Eye detector. No such events have been found in 6 x 106 sec of running time. We consequently set limits on the following: quark matter in the primary cosmic-ray flux, high-energy long-lived weakly interacting particles produced in proton-air interactions, such as Ď„'s; astrophysical neutrino flux; and other hypothetical high-energy weakly interacting components of the cosmic-ray flux such as photinos
Evidence for a high-energy cosmic-ray spectrum cutoff
Journal ArticleWe report a measurement of the ultrahigh-energy cosmic-ray spectrum using an atmospheric fluorescence technique for extensive-air-shower detection. The differential spectrum between 0.1 and 10 EeV (1 EeV = 10^18 eV) is well fitted by a power law with slope 2.94 ±0.02. Above 10 EeV evidence is presented for the development of a spectral " bump " followed by a cutoff at 70 EeV
Cosmic rays and neutrino interactions beyond the standard model
Some solutions of the hierarchy problem of particle physics can lead to
significantly increased neutrino cross sections beyond the electroweak scale.
We discuss some consequences for and constraints resulting from cosmic ray
physics.Comment: 3 latex pages, 1 postscript figure included, to appear in the TAUP 99
Proceedings, Nucl. Phys. B (Proc. Suppl.), ed. by M. Froissart, J. Dumarchez
and D. Vignau
Longitudinal development of extensive air showers: hybrid code SENECA and full Monte Carlo
New experiments, exploring the ultra-high energy tail of the cosmic ray
spectrum with unprecedented detail, are exerting a severe pressure on extensive
air hower modeling. Detailed fast codes are in need in order to extract and
understand the richness of information now available. Some hybrid simulation
codes have been proposed recently to this effect (e.g., the combination of the
traditional Monte Carlo scheme and system of cascade equations or pre-simulated
air showers). In this context, we explore the potential of SENECA, an efficient
hybrid tridimensional simulation code, as a valid practical alternative to full
Monte Carlo simulations of extensive air showers generated by ultra-high energy
cosmic rays. We extensively compare hybrid method with the traditional, but
time consuming, full Monte Carlo code CORSIKA which is the de facto standard in
the field. The hybrid scheme of the SENECA code is based on the simulation of
each particle with the traditional Monte Carlo method at two steps of the
shower development: the first step predicts the large fluctuations in the very
first particle interactions at high energies while the second step provides a
well detailed lateral distribution simulation of the final stages of the air
shower. Both Monte Carlo simulation steps are connected by a cascade equation
system which reproduces correctly the hadronic and electromagnetic longitudinal
profile. We study the influence of this approach on the main longitudinal
characteristics of proton-induced air showers and compare the predictions of
the well known CORSIKA code using the QGSJET hadronic interaction model.Comment: 11 pages (LaTeX), 15 postscript figures, 3 table
Influence of shower fluctuations and primary composition on studies of the shower longitudinal development
We study the influence of shower fluctuations, and the possible presence of
different nuclear species in the primary cosmic ray spectrum, on the
experimental determination of both shower energy and the proton air inelastic
cross section from studies of the longitudinal development of atmospheric
showers in fluorescence experiments. We investigate the potential of track
length integral and shower size at maximum as estimators of shower energy. We
find that at very high energy (~10^19-10^20 eV) the error of the total energy
assignment is dominated by the dependence on the hadronic interaction model,
and is of the order of 5%. At lower energy (~10^17-10^18 eV), the uncertainty
of the energy determination due to the limited knowledge of the primary cosmic
ray composition is more important. The distribution of depth of shower maximum
is discussed as a measure of the proton-air cross section. Uncertainties in a
possible experimental measurement of this cross section introduced by intrinsic
shower fluctuations, the model of hadronic interactions, and the unknown
mixture of primary nuclei in the cosmic radiation are numerically evaluated.Comment: 12 pages, 11 figures, 4 table
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