288,146 research outputs found
Finite element formulation for linear thermoviscoelastic materials
Report presents the finite difference equations in time and finite element matrix equations in space for general linear thermovisoelastic problems. The equations are derived for a general three-dimensional body but are applicable to one- and two-dimensional configurations with minor changes
An analysis of performance estimation methods for aircraft
Measurements and analytical extrapolation validity in predicting full scale flight performance from model wind tunnel test
Lyapunov functions from auxiliary exact differential equations
Use of auxiliary differential equations derived from nonlinear differential equations to find Lyapunov functio
Magic Wavelengths for Terahertz Clock Transitions
Magic wavelengths for laser trapping of boson isotopes of alkaline-earth Sr,
Ca and Mg atoms are investigated while considering terahertz clock transitions
between the metastable triplet states. Our
calculation shows that magic wavelengths of trapping laser do exist. This
result is important because those metastable states have already been used to
realize accurate clocks in the terahertz frequency domain. Detailed discussions
for magic wavelength for terahertz clock transitions are given in this paper.Comment: 7 page
Lyapunov functions and the exact differential equation
Liapunov functions and exact differential equatio
Sudden bending of cracked laminates
A dynamic approximate laminated plate theory is developed with emphasis placed on obtaining effective solution for the crack configuration where the 1/square root of r stress singularity and the condition of plane strain are preserved. The radial distance r is measured from the crack edge. The results obtained show that the crack moment intensity tends to decrease as the crack length to laminate plate thickness is increased. Hence, a laminated plate has the desirable feature of stabilizing a through crack as it increases its length at constant load. Also, the level of the average load intensity transmitted to a through crack can be reduced by making the inner layers to be stiffer than the outer layers. The present theory, although approximate, is useful for analyzing laminate failure to crack propagation under dynamic load conditions
Vertex nomination schemes for membership prediction
Suppose that a graph is realized from a stochastic block model where one of
the blocks is of interest, but many or all of the vertices' block labels are
unobserved. The task is to order the vertices with unobserved block labels into
a ``nomination list'' such that, with high probability, vertices from the
interesting block are concentrated near the list's beginning. We propose
several vertex nomination schemes. Our basic - but principled - setting and
development yields a best nomination scheme (which is a Bayes-Optimal
analogue), and also a likelihood maximization nomination scheme that is
practical to implement when there are a thousand vertices, and which is
empirically near-optimal when the number of vertices is small enough to allow
comparison to the best nomination scheme. We then illustrate the robustness of
the likelihood maximization nomination scheme to the modeling challenges
inherent in real data, using examples which include a social network involving
human trafficking, the Enron Graph, a worm brain connectome and a political
blog network.Comment: Published at http://dx.doi.org/10.1214/15-AOAS834 in the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Continuous Charge Modulated Diagonal Phase in Manganites
We present a novel ground state that explain the continuous modulated charge
diagonal order recently observed in manganese oxides, at hole densities
larger than one half. In this diagonal phase the charge is modulated with a
predominant Fourier component inversely proportional to . Magnetically
this state consist of antiferromagnetic coupled zig-zag chains. For a wide
range of relevant physical parameters as electron-phonon coupling,
antiferromagnetic interaction between Mn ions and on-site Coulomb repulsion,
the diagonal phase is the ground state of the system. The diagonal phase is
favored by the modulation of the hopping amplitude along the zig-zag chains,
and it is stabilized with respect to the one dimensional straight chain by the
electron phonon coupling. For realistic estimation of the physical parameters,
the diagonal modulation of the electron density is only a small fraction of the
average charge, a modulation much smaller than the obtained by distributing
Mn and Mn ions. We discuss also the spin and orbital structure
properties of this new diagonal phase.Comment: 4 pages, 4 figures include
Entanglement can completely defeat quantum noise
We describe two quantum channels that individually cannot send any
information, even classical, without some chance of decoding error. But
together a single use of each channel can send quantum information perfectly
reliably. This proves that the zero-error classical capacity exhibits
superactivation, the extreme form of the superadditivity phenomenon in which
entangled inputs allow communication over zero capacity channels. But our
result is stronger still, as it even allows zero-error quantum communication
when the two channels are combined. Thus our result shows a new remarkable way
in which entanglement across two systems can be used to resist noise, in this
case perfectly. We also show a new form of superactivation by entanglement
shared between sender and receiver.Comment: 4 pages, 1 figur
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