288,146 research outputs found

    Finite element formulation for linear thermoviscoelastic materials

    Get PDF
    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

    Get PDF
    Measurements and analytical extrapolation validity in predicting full scale flight performance from model wind tunnel test

    Lyapunov functions from auxiliary exact differential equations

    Get PDF
    Use of auxiliary differential equations derived from nonlinear differential equations to find Lyapunov functio

    Magic Wavelengths for Terahertz Clock Transitions

    Full text link
    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 3P0,3P1,3P2^{3}P_{0}, ^{3}P_{1}, ^{3}P_{2} 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

    Get PDF
    Liapunov functions and exact differential equatio

    Sudden bending of cracked laminates

    Get PDF
    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

    Full text link
    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

    Full text link
    We present a novel ground state that explain the continuous modulated charge diagonal order recently observed in manganese oxides, at hole densities xx larger than one half. In this diagonal phase the charge is modulated with a predominant Fourier component inversely proportional to 1x1-x. 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+3^{+3} and Mn+4^{+4} 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

    Get PDF
    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
    corecore