8,612 research outputs found
Randomized longest-queue-first scheduling for large-scale buffered systems
We develop diffusion approximations for parallel-queueing systems with the
randomized longest-queue-first scheduling algorithm by establishing new
mean-field limit theorems as the number of buffers . We achieve
this by allowing the number of sampled buffers to depend on the number
of buffers , which yields an asymptotic `decoupling' of the queue length
processes.
We show through simulation experiments that the resulting approximation is
accurate even for moderate values of and . To our knowledge, we are
the first to derive diffusion approximations for a queueing system in the
large-buffer mean-field regime. Another noteworthy feature of our scaling idea
is that the randomized longest-queue-first algorithm emulates the
longest-queue-first algorithm, yet is computationally more attractive. The
analysis of the system performance as a function of is facilitated by
the multi-scale nature in our limit theorems: the various processes we study
have different space scalings. This allows us to show the trade-off between
performance and complexity of the randomized longest-queue-first scheduling
algorithm
Recommended from our members
Further improving the accuracy of fetal foot length to confirm gestational duration: Additional data.
Anisotropy and Strong-Coupling Effects on the Collective Mode Spectrum of Chiral Superconductors: Application to SrRuO
Recent theories of SrRuO based on the interplay of strong
interactions, spin-orbit coupling and multi-band anisotropy predict chiral or
helical ground states with strong anisotropy of the pairing states, with deep
minima in the excitation gap, as well as strong phase anisotropy for the chiral
ground state. We develop time-dependent mean field theory to calculate the
Bosonic spectrum for the class of 2D chiral superconductors spanning He-A
to chiral superconductors with strong anisotropy. Chiral superconductors
support a pair of massive Bosonic excitations of the time-reversed pairs
labeled by their parity under charge conjugation. These modes are degenerate
for 2D He-A. Crystal field anisotropy lifts the degeneracy. Strong
anisotropy also leads to low-lying Fermions, and thus to channels for the decay
of the Bosonic modes. Selection rules and phase space considerations lead to
large asymmetries in the lifetimes and hybridization of the Bosonic modes with
the continuum of un-bound Fermion pairs. We also highlight results for the
excitation of the Bosonic modes by microwave radiation that provide clear
signatures of the Bosonic modes of an anisotropic chiral ground state.Comment: 11 pages with 8 figures. Presented as an invited talk as SCES14,
Grenoble, France, July 201
Disjoint edges in topological graphs and the tangled-thrackle conjecture
It is shown that for a constant , every simple topological
graph on vertices has edges if it has no two sets of edges such
that every edge in one set is disjoint from all edges of the other set (i.e.,
the complement of the intersection graph of the edges is -free). As an
application, we settle the \emph{tangled-thrackle} conjecture formulated by
Pach, Radoi\v{c}i\'c, and T\'oth: Every -vertex graph drawn in the plane
such that every pair of edges have precisely one point in common, where this
point is either a common endpoint, a crossing, or a point of tangency, has at
most edges
Unexpected contraction of a zeolite framework upon isomorphous substitution of Si by Al
Isomorphous substitution of Si by Al in the framework of sodalites synthesized in ethylene glycol causes an unexpected contraction of the zeolite framework
Dynamic Origin of Vortex Core Switching in Soft Magnetic Nanodots
The magnetic vortex with the in-plane curling magnetization and the
out-of-plane magnetization at the core is a unique ground state in nanoscale
magnetic elements. This kind of magnetic vortex can be used as a memory unit
for information storage, through its downward or upward core-orientation and,
thus, controllable core switching deserves some special attention. Our
analytical and micromagnetic calculations reveal that the origin of the vortex
core reversal is a gyrotropic field. This field is induced by vortex dynamic
motion and is proportional to the velocity of the moving vortex. Our
calculations elucidate the physical origin of the vortex core dynamic reversal
and offer a key to effective manipulation of the vortex-core orientation.Comment: 17 pages and 3 figure
Narrative Health Communication and Behavior Change: The Influence of Exemplars in the News on Intention to Quit Smoking.
This study investigated psychological mechanisms underlying the effect of narrative health communication on behavioral intention. Specifically, the study examined how exemplification in news about successful smoking cessation affects recipients\u27 narrative engagement, thereby changing their intention to quit smoking. Nationally representative samples of U.S. adult smokers participated in 2 experiments. The results from the 2 experiments consistently showed that smokers reading a news article with an exemplar experienced greater narrative engagement compared to those reading an article without an exemplar. Those who reported more engagement were in turn more likely to report greater smoking cessation intentions
Charge and spin collective modes in a quasi-1D model of Sr2RuO4
Given that Sr2RuO4 is a two-component p-wave superconductor, there exists the
possibility of well defined collective modes corresponding to fluctuations of
the relative phase and spin-orientation of the two components of the order
parameter. We demonstrate that at temperatures much below Tc, these modes have
energies small compared to the pairing gap scale if the superconductivity
arises primarily from the quasi 1D (dxz and dyz) bands, while it is known that
their energies become comparable to the pairing gap scale if there is a
substantial involvement of the quasi 2D (dxy) band. Therefore, the orbital
origin of the superconductivity can be determined by measuring the energies of
these collective modes.Comment: 11 pages (6 pages for main text), 2 figure
- …