10,644 research outputs found
Condensers and or evaporators in convective and radiative environments
Condensers and/or evaporators in convective and radiative environment
Local control of Hamiltonian chaos
We review a method of control for Hamiltonian systems which is able to create
smooth invariant tori. This method of control is based on an apt modification
of the perturbation which is small and localized in phase space
Diffraction-limited CCD imaging with faint reference stars
By selecting short exposure images taken using a CCD with negligible readout
noise we obtained essentially diffraction-limited 810 nm images of faint
objects using nearby reference stars brighter than I=16 at a 2.56 m telescope.
The FWHM of the isoplanatic patch for the technique is found to be 50
arcseconds, providing ~20% sky coverage around suitable reference stars.Comment: 4 page letter accepted for publication in Astronomy and Astrophysic
Aging, Emotion, Attention, and Binding in the Taboo Stroop Task: Data and Theories.
How does aging impact relations between emotion, memory, and attention? To address this question, young and older adults named the font colors of taboo and neutral words, some of which recurred in the same font color or screen location throughout two color-naming experiments. The results indicated longer color-naming response times (RTs) for taboo than neutral base-words (taboo Stroop interference); better incidental recognition of colors and locations consistently associated with taboo versus neutral words (taboo context-memory enhancement); and greater speed-up in color-naming RTs with repetition of color-consistent than color-inconsistent taboo words, but no analogous speed-up with repetition of location-consistent or location-inconsistent taboo words (the consistency type by repetition interaction for taboo words). All three phenomena remained constant with aging, consistent with the transmission deficit hypothesis and binding theory, where familiar emotional words trigger age-invariant reactions for prioritizing the binding of contextual features to the source of emotion. Binding theory also accurately predicted the interaction between consistency type and repetition for taboo words. However, one or more aspects of these phenomena failed to support the inhibition deficit hypothesis, resource capacity theory, or socio-emotional selectivity theory. We conclude that binding theory warrants further test in a range of paradigms, and that relations between aging and emotion, memory, and attention may depend on whether the task and stimuli trigger fast-reaction, involuntary binding processes, as in the taboo Stroop paradigm
Prediction of the Atomization Energy of Molecules Using Coulomb Matrix and Atomic Composition in a Bayesian Regularized Neural Networks
Exact calculation of electronic properties of molecules is a fundamental step
for intelligent and rational compounds and materials design. The intrinsically
graph-like and non-vectorial nature of molecular data generates a unique and
challenging machine learning problem. In this paper we embrace a learning from
scratch approach where the quantum mechanical electronic properties of
molecules are predicted directly from the raw molecular geometry, similar to
some recent works. But, unlike these previous endeavors, our study suggests a
benefit from combining molecular geometry embedded in the Coulomb matrix with
the atomic composition of molecules. Using the new combined features in a
Bayesian regularized neural networks, our results improve well-known results
from the literature on the QM7 dataset from a mean absolute error of 3.51
kcal/mol down to 3.0 kcal/mol.Comment: Under review ICANN 201
Stability of non-time-reversible phonobreathers
Non-time reversible phonobreathers are non-linear waves that can transport
energy in coupled oscillator chains by means of a phase-torsion mechanism. In
this paper, the stability properties of these structures have been considered.
It has been performed an analytical study for low-coupling solutions based upon
the so called {\em multibreather stability theorem} previously developed by
some of the authors [Physica D {\bf 180} 235]. A numerical analysis confirms
the analytical predictions and gives a detailed picture of the existence and
stability properties for arbitrary frequency and coupling.Comment: J. Phys. A.:Math. and Theor. In Press (2010
Community Detection as an Inference Problem
We express community detection as an inference problem of determining the
most likely arrangement of communities. We then apply belief propagation and
mean-field theory to this problem, and show that this leads to fast, accurate
algorithms for community detection.Comment: 4 pages, 2 figure
Stationary and moving breathers in a simplified model of curved alpha--helix proteins
The existence, stability and movability of breathers in a model for
alpha-helix proteins is studied. This model basically consists a chain of
dipole moments parallel to it. The existence of localized linear modes brings
about that the system has a characteristic frequency, which depends on the
curvature of the chain. Hard breathers are stable, while soft ones experiment
subharmonic instabilities that preserve, however the localization. Moving
breathers can travel across the bending point for small curvature and are
reflected when it is increased. No trapping of breathers takes place.Comment: 19 pages, 11 figure
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