3,740 research outputs found
Layer-switching cost and optimality in information spreading on multiplex networks
We study a model of information spreading on multiplex networks, in which
agents interact through multiple interaction channels (layers), say online vs.\
offline communication layers, subject to layer-switching cost for transmissions
across different interaction layers. The model is characterized by the
layer-wise path-dependent transmissibility over a contact, that is dynamically
determined dependently on both incoming and outgoing transmission layers. We
formulate an analytical framework to deal with such path-dependent
transmissibility and demonstrate the nontrivial interplay between the
multiplexity and spreading dynamics, including optimality. It is shown that the
epidemic threshold and prevalence respond to the layer-switching cost
non-monotonically and that the optimal conditions can change in abrupt
non-analytic ways, depending also on the densities of network layers and the
type of seed infections. Our results elucidate the essential role of
multiplexity that its explicit consideration should be crucial for realistic
modeling and prediction of spreading phenomena on multiplex social networks in
an era of ever-diversifying social interaction layers.Comment: 15 pages, 7 figure
Compounds affecting cholesterol absorption
A class of novel compounds is described for use in affecting lymphatic absorption of cholesterol. Compounds of particular interest are defined by Formula I: ##STR1## or a pharmaceutically acceptable salt thereof
Development of Transgenic Tall Fescue Plants with Enhanced Tolerance to Multiple Abiotic Stresses
Investigating the impacts of land use, climate and biodiversity changes on human health and wellbeing
Experimental ionization of atomic hydrogen with few-cycle pulses
We present the first experimental data on strong-field ionization of atomic
hydrogen by few-cycle laser pulses. We obtain quantitative agreement at the 10%
level between the data and an {\it ab initio} simulation over a wide range of
laser intensities and electron energies
RG flow of transport quantities
The RG flow equation of various transport quantities are studied in arbitrary
spacetime dimensions, in the fixed as well as fluctuating background geometry
both for the Maxwellian and DBI type of actions. The regularity condition on
the flow equation of the conductivity at the horizon for the DBI action
reproduces naturally the leading order result of {\it Hartnoll et al.}, [{\it
JHEP}, {\bf 04}, 120 (2010)]. Motivated by the result of {\it van der Marel et
al.}, [{\it science}, {\bf 425}, 271 (2003], we studied, analytically, the
conductivity versus frequency plane by dividing it into three distinct parts:
and . In order to compare, we choose 3+1
dimensional bulk spacetime for the computation of the conductivity. In the
range, the conductivity does not show up the Drude like form in any
spacetime dimensions. In the range and staying away from the
horizon, for the DBI action with unit dynamical exponent, non-zero magnetic
field and charge density, the conductivity goes as , whereas the
phase of the conductivity, goes as,
and . There exists a universal
quantity at the horizon that is the phase angle of conductivity, which either
vanishes or an integral multiple of . Furthermore, we calculate the
temperature dependence to the thermoelectric and the thermal conductivity at
the horizon. The charge diffusion constant for the DBI action is studied.Comment: 1+68 pages, 12 figures and 4 appendices; V2: The charge diffusion
constant is calculated for arbitrary spacetime dimensions and related
references added; v3: Connection with the RG flow of 1010.4036 is made; v4:
Several corrections, typos fixed and a ref. adde
Magnetic Response of Hydrothermally Prepared Self-Assembled Co3O4 Nano-platelets
In the present communication, we report a strong ferrimagnetic behavior of self-assembled Co[subscript 3]O[subscript 4] nano-platelets, which most likely originates from the intrinsic spin structure of the unique Co[subscript 3]O[subscript 4] structure. The microsphere-like structures are composed of nano-platelets that are entangled together to form the organized network. These anomalous ferrimagnetic properties can be rationalized by supposing that one of the Co[superscript 3+] and one of the Co[superscript 2+] ions are switched between the octahedral and tetrahedral sites. The powder sample was also characterized by x-ray diffraction and superconducting quantum interface device magnetometry.National Research Foundation of Korea (No. 2013029776 (Mid-career Researcher Program)) Remove selectedResearch Institute for Solar and Sustainable Energies (Core Technology Development Program
Dynamic origin of azimuthal modes splitting in vortex-state magnetic dots
A spin wave theory explaining experimentally observed frequency splitting of
dynamical excitations with azimuthal symmetry of a magnetic dot in a vortex
ground state is developed. It is shown that this splitting is a result of the
dipolar hybridization of three spin wave modes of a dot having azimuthal
indices |m|=1: two high-frequency azimuthal excitation modes of the in-plane
part of the vortex with indices m = +/-1 and a low-frequency m= +1 gyrotropic
mode describing the translational motion of the vortex core. The analytically
calculated magnitude of the frequency splitting is proportional to the ratio of
the dot thickness to its radius and quantitatively agrees with the results of
time resolved Kerr experiments.Comment: 10 pages, 5 figure
One-Parameter Squeezed Gaussian States of Time-Dependent Harmonic Oscillator and Selection Rule for Vacuum States
By using the invariant method we find one-parameter squeezed Gaussian states
for both time-independent and time-dependent oscillators. The squeezing
parameter is expressed in terms of energy expectation value for
time-independent case and represents the degree of mixing positive and negative
frequency solutions for time-dependent case. A {\it minimum uncertainty
proposal} is advanced to select uniquely vacuum states at each moment of time.
We show that the Gaussian states with minimum uncertainty coincide with the
true vacuum state for time-independent oscillator and the Bunch-Davies vacuum
for a massive scalar field in a de Sitter spacetime.Comment: 13 Pages, ReVTeX, no figure
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