63,678 research outputs found
Atypical viral dynamics from transport through popular places
The flux of visitors through popular places undoubtedly influences viral
spreading -- from H1N1 and Zika viruses spreading through physical spaces such
as airports, to rumors and ideas spreading though online spaces such as
chatrooms and social media. However there is a lack of understanding of the
types of viral dynamics that can result. Here we present a minimal dynamical
model which focuses on the time-dependent interplay between the {\em mobility
through} and the {\em occupancy of} such spaces. Our generic model permits
analytic analysis while producing a rich diversity of infection profiles in
terms of their shapes, durations, and intensities. The general features of
these theoretical profiles compare well to real-world data of recent social
contagion phenomena.Comment: 14 pages, 16 figure
Odd-even mass staggering with Skyrme-Hartree-Fock-Bogoliubov theory
We have studied odd-even nuclear mass staggering with the
Skyrme-Hartree-Fock-Bogoliubov theory by employing isoscalar and isovector
contact pairing interactions. By reproducing the empirical odd-even mass
differences of the Sn isotopic chain, the strengths of pairing interactions are
determined. The optimal strengths adjusted in this work can give better
description of odd-even mass differences than that fitted by reproducing the
experimental neutron pairing gap of Sn.Comment: 9 pages, 3 figures, submitted to PRC Brief Repor
Anomalous Contagion and Renormalization in Dynamical Networks with Nodal Mobility
The common real-world feature of individuals migrating through a network --
either in real space or online -- significantly complicates understanding of
network processes. Here we show that even though a network may appear static on
average, underlying nodal mobility can dramatically distort outbreak profiles.
Highly nonlinear dynamical regimes emerge in which increasing mobility either
amplifies or suppresses outbreak severity. Predicted profiles mimic recent
outbreaks of real-space contagion (social unrest) and online contagion
(pro-ISIS support). We show that this nodal mobility can be renormalized in a
precise way for a particular class of dynamical networks
Hole Expansion Simulations of TWIP Steel Sheet Sample
In this work, the stretch flangeability of a TWIP steel sheet sample was investigated both experimentally and numerically through the hole expansion test. Uniaxial tension and disk compression tests were performed to characterize the flow behavior and plastic anisotropy for the TWIP steel sheet sample. The punch load-stroke curve, hole diameter and specimen surface strain distribution near the hole was measured. Then finite element simulations of the hole expansion test were carried out using the finite element code ABAQUS with three yield criteria: von Mises, Hill 1948 and Yld2000-2d. The predicted and experimental results were compared in terms of the final hole radii and the strain distribution.open111Nsciescopu
Characterization of multiqubit pure-state entanglement
A necessary and sufficient entanglement criterion based on variances of
Mermin-Klyshko's Bell operators is proved for multiqubit pure states. Contrary
to Bell's inequalities, entangled pure states strictly satisfy a quadratic
inequality but product ones can attain the equality under some local unitary
transformations, which can be obtained by solving a quadratic maximum problem.
This presents a characterization of multiqubit pure-state entanglement.Comment: 3 page
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