799 research outputs found
Exemplar Based Deep Discriminative and Shareable Feature Learning for Scene Image Classification
In order to encode the class correlation and class specific information in
image representation, we propose a new local feature learning approach named
Deep Discriminative and Shareable Feature Learning (DDSFL). DDSFL aims to
hierarchically learn feature transformation filter banks to transform raw pixel
image patches to features. The learned filter banks are expected to: (1) encode
common visual patterns of a flexible number of categories; (2) encode
discriminative information; and (3) hierarchically extract patterns at
different visual levels. Particularly, in each single layer of DDSFL, shareable
filters are jointly learned for classes which share the similar patterns.
Discriminative power of the filters is achieved by enforcing the features from
the same category to be close, while features from different categories to be
far away from each other. Furthermore, we also propose two exemplar selection
methods to iteratively select training data for more efficient and effective
learning. Based on the experimental results, DDSFL can achieve very promising
performance, and it also shows great complementary effect to the
state-of-the-art Caffe features.Comment: Pattern Recognition, Elsevier, 201
Heterogeneity in structurally arrested hard spheres
When cooled or compressed sufficiently rapidly, a liquid vitrifies into a glassy amorphous state. Vitrification in a dense liquid is associated with jamming of the particles. For hard spheres, the density and degree of order in the final structure depend on the compression rate: simple intuition suggests, and previous computer simulation demonstrates, that slower compression results in states that are both denser and more ordered. In this work, we use the Lubachevsky-Stillinger algorithm to generate a sequence of structurally arrested hard-sphere states by varying the compression rate. We find that while the degree of order, as measured by both bond-orientation and translation order parameters, increases monotonically with decreasing compression rate, the density of the arrested state first increases, then decreases, then increases again, as the compression rate decreases, showing a minimum at an intermediate compression rate. Examination of the distribution of the local order parameters and the distribution of the root-mean-square fluctuation of the particle positions, as well as direct visual inspection of the arrested structures, reveal that they are structurally heterogeneous, consisting of disordered, amorphous regions and locally ordered crystal-like domains. In particular, the low-density arrested states correspond with many interconnected small crystal clusters that form a polycrystalline network interspersed in an amorphous background, suggesting that jamming by the domains may be an important mechanism for these states
Surface Charge Density in Electrical Double Layer Capacitors with Nanoscale Cathode–Anode Separation
Using a dynamic density functional theory, we study the charging dynamics, the final equilibrium structure, and the energy storage in an electrical double layer capacitor with nanoscale cathode–anode separation in a slit geometry. We derive a simple expression for the surface charge density that naturally separates the effects of the charge polarization due to the ions from those due to the polarization of the dielectric medium and allows a more intuitive understanding of how the ion distribution within the cell affects the surface charge density. We find that charge neutrality in the half-cell does not hold during the dynamic charging process for any cathode–anode separation, and also does not hold at the final equilibrium state for small separations. Therefore, the charge accumulation in the half-cell in general does not equal the surface charge density. The relationships between the surface charge density and the charge accumulation within the half-cell are systematically investigated by tuning the electrolyte concentration, cathode–anode separation, and applied voltage. For high electrolyte concentrations, we observe charge inversion at which the charge accumulation exceeds the surface charge at special values of the separation. In addition, we find that the energy density has a maximum at intermediate electrolyte concentrations for a high applied voltage
Bicuspid aortic stenosis in transcatheter aortic valve replacement era: Emerging confusions hindering the standardization of the procedure
Poly[[di-μ3-nicotinato-μ3-oxalato-samarium(III)silver(I)] dihydrate]
In the title three-dimensional heterometallic complex, {[AgSm(C6H4NO2)2(C2O4)]·2H2O}n, the SmIII ion is eight-coordinated by four O atoms from four different nicotinate ligands and four O atoms from two different oxalate ligands. The three-coordinate AgI ion is bonded to two N atoms from two different nicotinate anions and one O atom from an oxalate anion. These metal coordination units are connected by bridging nicotinate and oxalate ligands, generating a three-dimensional network. The uncoordinated water molecules link the carboxylate groups via O—H⋯O hydrogen bonding. The crystal structure is further stabilized by hydrogen bonds between the water molecules
The effect of flower position on variation and covariation in floral traits in a wild hermaphrodite plant
<p>Abstract</p> <p>Background</p> <p>Floral traits within plants can vary with flower position or flowering time. Within an inflorescence, sexual allocation of early produced basal flowers is often female-biased while later produced distal flowers are male-biased. Such temporal adjustment of floral resource has been considered one of the potential advantages of modularity (regarding a flower as a module) in hermaphrodites. However, flowers are under constraints of independent evolution of a given trait. To understand flower diversification within inflorescences, here we examine variation and covariation in floral traits within racemes at the individual and the maternal family level respectively in an alpine herb <it>Aconitum gymnandrum </it>(Ranunculaceae).</p> <p>Results</p> <p>We found that floral traits varied significantly with flower position and among families, and position effects were family-specific. Most of the variance of floral traits was among individuals rather than among flowers within individuals or among families. Significant phenotypic correlations between traits were not affected by position, indicating trait integration under shared developmental regulation. In contrast, positive family-mean correlations in floral traits declined gradually from basal to distal flowers (nine significant correlations among floral traits in basal flowers and only three in distal flowers), showing position-specificity. Therefore, the pattern and magnitude of genetic correlations decreased with flower position.</p> <p>Conclusions</p> <p>This finding on covariation pattern in floral reproductive structures within racemes has not been revealed before, providing insights into temporal variation and position effects in floral traits within plants and the potential advantages of modularity in hermaphrodites.</p
Poly[[di-μ3-nicotinato-μ3-oxalato-samarium(III)silver(I)] dihydrate]. Corrigendum
Corrigendum to Acta Cryst. (2009), E65, m1105
Radiative decays of the heavy-quark-spin molecular partner of
With the assumptions that the discovered at LHCb is a
hadronic molecule, using a nonrelativistic effective field theory we calculate
the radiative partial widths of with being
a shallow bound state and the heavy-quark-spin partner of
. The rescattering effect with the pole is
taken into account. The results show that the isoscalar
rescattering can increase the tree-level decay width of by about , while decrease that of
by a similar amount. The two-body
partial decay widths of the into and
are also calculated, and the results are about and
, respectively. Considering that the needs to be
reconstructed from the or final state in an experimental
measurement, the four-body partial widths of the into
and are explicitly calculated, and we find that
the interference effect between different intermediate states is
small. The total radiative decay width of the is predicted to be
about . Adding the hadronic decay widths of , the total width of the is finally predicted to be
keV.Comment: 27 pages, 13 figures. arXiv admin note: text overlap with
arXiv:2211.0247
Bis[4-hydroxy-3,5-dimethoxybenzaldehyde (2,4-dinitrophenyl)hydrazone] N,N-dimethylformamide disolvate monohydrate
In the title compound, 2C15H14N4O7·2C3H7NO·H2O, the hydrazone molecules are roughly planar, with the two benzene rings twisted slightly relative to each other by dihedral angle of 6.04 (11) and 7.75 (11)° in the two molecules. The water molecule is linked to the Schiff base molecule by an O—H⋯O hydrogen bond. Intramolecular N—H⋯O hydrogen bonds occur. In the crystal, molecules are linked by intermolecular N—H⋯O and O—H⋯O hydrogen bonds
- …