32,661 research outputs found
RepFlow: Minimizing Flow Completion Times with Replicated Flows in Data Centers
Short TCP flows that are critical for many interactive applications in data
centers are plagued by large flows and head-of-line blocking in switches.
Hash-based load balancing schemes such as ECMP aggravate the matter and result
in long-tailed flow completion times (FCT). Previous work on reducing FCT
usually requires custom switch hardware and/or protocol changes. We propose
RepFlow, a simple yet practically effective approach that replicates each short
flow to reduce the completion times, without any change to switches or host
kernels. With ECMP the original and replicated flows traverse distinct paths
with different congestion levels, thereby reducing the probability of having
long queueing delay. We develop a simple analytical model to demonstrate the
potential improvement of RepFlow. Extensive NS-3 simulations and Mininet
implementation show that RepFlow provides 50%--70% speedup in both mean and
99-th percentile FCT for all loads, and offers near-optimal FCT when used with
DCTCP.Comment: To appear in IEEE INFOCOM 201
Study on space-time structure of Higgs boson decay using HBT correlation Method in ee collision at =250 GeV
The space-time structure of the Higgs boson decay are carefully studied with
the HBT correlation method using ee collision events produced through
Monte Carlo generator PYTHIA 8.2 at =250GeV. The Higgs boson jets
(Higgs-jets) are identified by H-tag tracing. The measurement of the Higgs
boson radius and decay lifetime are derived from HBT correlation of its decay
final state pions inside Higgs-jets in the ee collisions events with an
upper bound of fm and fs. This result is consistent with CMS data.Comment: 7 pages,3 figure
Two decades of advances in high-resolution spectroscopy of large-amplitude motions in n-fold potential wells, as illustrated by methanol
Methanol is a simple and intensively studied organic molecule possessing one large-amplitude torsional motion. It has, for nearly a century, been a favorite of researchers in many fields, e.g., instrument builders, for whom methanol is often the first molecule chosen for testing an improved or a newly built instrument (including HIFI, the Heterodyne Instrument for the Far Infrared on board the Herschel space mission)theorists and/or dynamicists studying the challenging effects of a large-amplitude motion coupling with small-amplitude motions to enhance intramolecular vibrational energy redistributionastronomers who have elevated methanol to their 1 interstellar weed because of its rich and omnipresent spectrum in the interstellar garden, where it serves as a unique probe for diagnosing conditions in star-forming regionsastrochemists studying isotopic ratios as clues to the chemical evolution of the universeand fundamentalists seeking possible time variation of the proton/electron mass ratio in the standard modeljust to name a few.
From high-resolution to high-precision spectroscopy, the large-amplitude internal rotation of the methyl top against its OH framework in methanol has never failed to produce new surprises in spectral regions from the microwave all the way to the near IR. The very recent observation of completely unexpected large methanol hyperfine splittings is a vivid testimonial that the large-amplitude torsional motion can still lead us to unexplored landscapes. This talk will focus on the complicated vibration-torsion-rotation energy networks and interactions deduced from high resolution spectraour efforts to understand some of them using ab-initio-assisted approaches and the modeling of torsion-rotation and torsionally mediated spin-rotation hyperfine splittings in methanol. These topics represent one part of the much larger fascinating world inhabited by methanolics
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