31,365 research outputs found
Quasi-Dirac neutrinos and solar neutrino data
We present an analysis of the solar neutrino data in the context of a
quasi-Dirac neutrino model in which the lepton mixing matrix is given at tree
level by the tribimaximal matrix. When radiative corrections are taken into
account, new effects in neutrino oscillations, as , appear.
This oscillation is constrained by the solar neutrino data. In our analysis, we
have found an allowed region for our two free parameters and .
The radiative correction, , can vary approximately from to and the calculated fourth mass eigenstate, , 0.01 eV
to 0.2 eV at 2 level. These results are very similar to the ones
presented in the literature.Comment: 24 pages, 7 figures and 2 tables. Results and conclusion unchanged.
Version published in EPJC. Figures improve
GHASP: an H{\alpha} kinematic survey of spiral and irregular galaxies -- IX. The NIR, stellar and baryonic Tully-Fisher relations
We studied, for the first time, the near infrared, stellar and baryonic
Tully-Fisher relations for a sample of field galaxies taken from an homogeneous
Fabry-Perot sample of galaxies (the GHASP survey). The main advantage of GHASP
over other samples is that maximum rotational velocities were estimated from 2D
velocity fields, avoiding assumptions about the inclination and position angle
of the galaxies. By combining these data with 2MASS photometry, optical colors,
HI masses and different mass-to-light ratio estimators, we found a slope of
4.48\pm0.38 and 3.64\pm0.28 for the stellar and baryonic Tully-Fisher relation,
respectively. We found that these values do not change significantly when
different mass-to-light ratios recipes were used. We also point out, for the
first time, that rising rotation curves as well as asymmetric rotation curves
show a larger dispersion in the Tully-Fisher relation than flat ones or than
symmetric ones. Using the baryonic mass and the optical radius of galaxies, we
found that the surface baryonic mass density is almost constant for all the
galaxies of this sample. In this study we also emphasize the presence of a
break in the NIR Tully-Fisher relation at M(H,K)\sim-20 and we confirm that
late-type galaxies present higher total-to-baryonic mass ratios than early-type
spirals, suggesting that supernova feedback is actually an important issue in
late-type spirals. Due to the well defined sample selection criteria and the
homogeneity of the data analysis, the Tully-Fisher relation for GHASP galaxies
can be used as a reference for the study of this relation in other environments
and at higher redshifts.Comment: 16 pages, 6 figures. Accepted for publication in MNRA
Eye-CU: Sleep Pose Classification for Healthcare using Multimodal Multiview Data
Manual analysis of body poses of bed-ridden patients requires staff to
continuously track and record patient poses. Two limitations in the
dissemination of pose-related therapies are scarce human resources and
unreliable automated systems. This work addresses these issues by introducing a
new method and a new system for robust automated classification of sleep poses
in an Intensive Care Unit (ICU) environment. The new method,
coupled-constrained Least-Squares (cc-LS), uses multimodal and multiview (MM)
data and finds the set of modality trust values that minimizes the difference
between expected and estimated labels. The new system, Eye-CU, is an affordable
multi-sensor modular system for unobtrusive data collection and analysis in
healthcare. Experimental results indicate that the performance of cc-LS matches
the performance of existing methods in ideal scenarios. This method outperforms
the latest techniques in challenging scenarios by 13% for those with poor
illumination and by 70% for those with both poor illumination and occlusions.
Results also show that a reduced Eye-CU configuration can classify poses
without pressure information with only a slight drop in its performance.Comment: Ten-page manuscript including references and ten figure
SACY - a Search for Associations Containing Young stars
The scientific goal of the SACY (Search for Associations Containing
Young-stars) was to identify possible associations of stars younger than the
Pleiades Association among optical counterparts of the ROSAT X-ray bright
sources. High-resolution spectra for possible optical counterparts later than
G0 belonging to HIPPARCOS and/or TYCHO-2 catalogs were obtained in order to
assess both the youth and the spatial motion of each target. More than 1000
ROSAT sources were observed, covering a large area in the Southern Hemisphere.
The newly identified young stars present a patchy distribution in UVW and XYZ,
revealing the existence of huge nearby young associations. Here we present the
associations identified in this survey.Comment: 8 pages, 2 figures, to appear in the Proceedings of Open Issues in
Local Formation and Early Stellar Evolution, Ouro Preto, Brazi
Radio detection of the young binary HD 160934
Precise determination of dynamical masses of pre-main-sequence (PMS) stars is
essential to calibrate stellar evolution models that are widely used to derive
theoretical masses of young low-mass objects. Binary stars in young, nearby
loose associations are particularly good candidates for this calibration since
all members share a common age. Interestingly, some of these young binaries
present a persistent and compact radio emission, which makes them excellent
targets for astrometric VLBI studies. We aim to monitor the orbital motion of
the binary system HD 160934, a member of the AB Doradus moving group. We
observed HD 160934 with the Very Large Array and the European VLBI Network at
8.4 and 5 GHz, respectively. The orbital information derived from these
observations was analyzed along with previously reported orbital measurements.
We show that the two components of the binary, HD 160934 A and HD 160934 c,
display compact radio emission at VLBI scales, providing precise information on
the relative orbit. Revised orbital elements were estimated. Future VLBI
monitoring of this pair should determine precise model-independent mass
estimates for the A and c components, which will serve as calibration tests for
PMS evolutionary models.Comment: 5 pages, 5 figures, accepted for publication in A&
Controle biológico como opção no manejo de pragas do algodoeiro.
Manejo de pragasbitstream/item/109011/1/CNPACIRTEC72.pd
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