763 research outputs found
Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third Edition - Comments and Statistics
The Catalogue, available at the Centre de Donn\'ees Stellaires de Strasbourg,
consists of 13573 records concerning the results obtained from different
methods for 7778 stars, reported in the literature. The following data are
listed for each star: identifications, apparent magnitude, spectral type,
apparent diameter in arcsec, absolute radius in solar units, method of
determination, reference, remarks. Comments and statistics obtained from CADARS
are given.Comment: A&A, in pres
Surface phase transitions in one-dimensional channels arranged in a triangular cross-sectional structure: Theory and Monte Carlo simulations
Monte Carlo simulations and finite-size scaling analysis have been carried
out to study the critical behavior in a submonolayer lattice-gas of interacting
monomers adsorbed on one-dimensional channels arranged in a triangular
cross-sectional structure. The model mimics a nanoporous environment, where
each nanotube or unit cell is represented by a one-dimensional array. Two kinds
of lateral interaction energies have been considered: , interaction
energy between nearest-neighbor particles adsorbed along a single channel and
, interaction energy between particles adsorbed across
nearest-neighbor channels. For and , successive planes are
uncorrelated, the system is equivalent to the triangular lattice and the
well-known
ordered phase is found at low temperatures and a coverage, , of 1/3
. In the more general case ( and ), a
competition between interactions along a single channel and a transverse
coupling between sites in neighboring channels allows to evolve to a
three-dimensional adsorbed layer. Consequently, the and structures "propagate" along the
channels and new ordered phases appear in the adlayer. The Monte Carlo
technique was combined with the recently reported Free Energy Minimization
Criterion Approach (FEMCA), to predict the critical temperatures of the
order-disorder transformation. The excellent qualitative agreement between
simulated data and FEMCA results allow us to interpret the physical meaning of
the mechanisms underlying the observed transitions.Comment: 24 pages, 6 figure
Income Distribution in a Monetary Economy: A Ricardo-Keynes Synthesis
The paper provides a novel theory of income distribution and achieves an integration of monetary and value theories along Ricardian lines, extended to a monetary production economy as understood by Keynes. In a monetary economy, capital is a fund that must be maintained. This idea is captured in the circuit of capital as first defined by Marx. We introduce the circuit of fixed capital; this circuit is closed when the present value of prospective returns from employing it is equal to its supply price. In a steady-growth equilibrium with nominal wages and interest rates given, the equation that closes the circuit of fixed capital can be solved for prices, implying a definitive income distribution. Accordingly, the imputation for fixed capital costs is equivalent to that of a money contract of equal length, which is the payment per period that will repay the cost of the fixed asset, together with interest. It follows that if capital assets remain in use for a period longer than is required to amortize them, their earnings beyond that period have an element of pure rent
Validation of a smart mirror for gesture recognition in gym training performed by a vision-based deep learning system
This paper illustrates the development and validation of a smart mirror for sports training. The application is based on the skeletonization algorithm MediaPipe and runs on an embedded device Nvidia Jetson Nano equipped with two fisheye cameras. The software has been evaluated considering the exercise biceps curl. The elbow angle has been measured by both MediaPipe and the motion capture system BTS (ground truth), and the resulting values have been compared to determine angle uncertainty, residual errors, and intra-subject and inter-subject repeatability. The uncertainty of the joints’ estimation and the quality of the image captured by the cameras reflect on the final uncertainty of the indicator over time, highlighting the areas of improvement for further development
Standard and inverse site percolation of straight rigid rods on triangular lattices: Isotropic and nematic deposition/removal
Numerical simulations and finite-size scaling analysis have been carried out
to study standard and inverse percolation of straight rigid rods on triangular
lattices. In the case of standard (inverse) percolation, the lattice is
initially empty(occupied) and linear -mers ( linear consecutive sites)
are randomly and sequentially deposited on(removed from) the lattice,
considering an isotropic and nematic scheme. The study is conducted by
following the behavior of four critical concentrations with the size ,
determined for a wide range of : [] standard isotropic[nematic]
percolation threshold [], and []
inverse isotropic[nematic] percolation threshold
[]. The obtained results indicate that:
[] exhibits a non-monotonous dependence
with . It decreases[increases], goes through a minimum[maximum] around , then increases and asymptotically converges towards a definite value for
large []; [] rapidly
increases[decreases] and asymptotically converges towards a definite value for
infinitely long -mers []; for
both models, the curves of standard and inverse percolation thresholds are
symmetric with respect to . Thus, a complementary property is
found (and ), which has not been observed in other regular lattices.
This condition is analytically validated by using exact enumeration of
configurations for small systems; and in all cases, the model presents
percolation transition for the whole range of
Critical behavior of repulsive linear -mers on triangular lattices
Monte Carlo (MC) simulations and finite-size scaling analysis have been
carried out to study the critical behavior in a submonolayer two-dimensional
gas of repulsive linear -mers on a triangular lattice at coverage
. A low-temperature ordered phase, characterized by a repetition of
alternating files of adsorbed -mers separated by adjacent empty sites,
is separated from the disordered state by a order-disorder phase transition
occurring at a finite critical temperature, . The MC technique was
combined with the recently reported Free Energy Minimization Criterion Approach
(FEMCA), [F. Rom\'a et al., Phys. Rev. B, 68, 205407, (2003)], to predict the
dependence of the critical temperature of the order-disorder transformation.
The dependence on of the transition temperature, , observed in MC
is in qualitative agreement with FEMCA. In addition, an accurate determination
of the critical exponents has been obtained for adsorbate sizes ranging between
and . For , the results reveal that the system does not belong
to the universality class of the two-dimensional Potts model with (,
monomers). Based on symmetry concepts, we suggested that the behavior observed
for and 3 could be generalized to include larger particle sizes ().Comment: 17 pages, 13 figure
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