7,361 research outputs found
How well do domain wall fermions realize chiral symmetry?
In the domain wall fermion formulation, chiral symmetry breaking in full QCD
is expected to fall exponentially with the length of the extra dimension. We
measure the chiral symmetry breaking due to a finite extra dimension in two
ways, which can be affected differently by finite volume and explicit fermion
mass. For quenched QCD the two methods generally agree, except for the largest
extent of the extra dimension, which makes the limit uncertain. We have less
data for full QCD, but see exponential suppression for the method where we have
data.Comment: 3 pages, 2 figures, LATTICE99(hightemp
Interacting staggered domain wall fermions
The behavior of staggered domain wall fermions in the presence of gauge
fields is presented. In particular, their response to gauge fields with
nontrivial topology is discussed.Comment: Lattice2002(Chiral) proceedings, LaTeX, 3 pages 2 eps figure
Spectral and Rotational Changes in the Isolated Neutron Star RX J0720.4-3125
RX J0720.4-3125 is an isolated neutron star that, uniquely in its class, has
shown changes in its thermal X-ray spectrum. We use new spectra taken with
Chandra's Low Energy Transmission Grating Spectrometer, as well as archival
observations, to try to understand the timescale and nature of these changes.
We construct lightcurves, which show both small, slow variations on a timescale
of years, and a larger event that occurred more quickly, within half a year.
From timing, we find evidence for a `glitch' coincident with this larger
event, with a fractional increase in spin frequency of 5x10^{-8}. We compare
the `before' and `after' spectra with those from RX J1308.6+2127, an isolated
neutron star with similar temperature and magnetic field strength, but with a
much stronger absorption feature in its spectrum. We find that the `after'
spectrum can be represented remarkably well by the superposition of the
`before' spectrum, scaled by two thirds, and the spectrum of RX J1308.6+2127,
thus suggesting that the event affected approximately one third of the surface.
We speculate the event reflects a change in surface composition caused by,
e.g., an accretion episode.Comment: 4 pages, 2 figures, 2 tables, emulateapj format. ApJL, accepte
Comparison of the Kaplan and Nagel anomaloscopes
Comparison of the Kaplan and Nagel anomaloscope
CPA elderCare/primePlus services : a practitioner\u27s resource guide;
CD-ROM files converted to PDF and included after main texthttps://egrove.olemiss.edu/aicpa_guides/1105/thumbnail.jp
Dynamical lattice QCD thermodynamics with domain wall fermions
We present results from simulations of two flavor QCD thermodynamics at N_t=4
with domain wall fermions. In contrast to other lattice fermion formulations,
domain wall fermions preserve the full chiral symmetry of the continuum at
finite lattice spacing (up to terms exponentially small in an extra parameter).
Just above the phase transition, we find that the axial U(1) symmetry is broken
only by a small amount. We discuss an ongoing calculation to determine the
order and properties of the phase transition using domain wall fermions, since
the global symmetries of the theory are expected to be important here.Comment: 4 pages, 4 eps figures, LaTeX. To appear in the Proceedings of the
XVth Particles and Nuclei International Conference (PANIC '99), Uppsala,
Sweden, 10-16 June 199
Empirical Analysis of the Strengths and Weaknesses of PEFT Techniques for LLMs
As foundation models continue to exponentially scale in size, efficient
methods of adaptation become increasingly critical. Parameter-efficient
fine-tuning (PEFT), a recent class of techniques that require only modifying a
small percentage of the model parameters, is currently the most popular method
for adapting large language models (LLMs). Several PEFT techniques have
recently been proposed with varying tradeoffs. We provide a comprehensive and
uniform benchmark of various PEFT techniques across a representative LLM, the
FLAN-T5 model, and evaluate model performance across different data scales of
classification and generation datasets. Based on this, we provide a framework
for choosing the optimal fine-tuning techniques given the task type and data
availability. Contrary to popular belief, we also empirically prove that PEFT
techniques converge slower than full tuning in low data scenarios, and posit
the amount of data required for PEFT methods to both perform well and converge
efficiently. Lastly, we further optimize these PEFT techniques by selectively
choosing which parts of the model to train, and find that these techniques can
be applied with significantly fewer parameters while maintaining and even
improving performance.Comment: Short paper, ICLR '23 Workshop on Understanding Foundation Model
Steroid Therapy for Bacterial Meningitis
Routine dexamethasone therapy for bacterial meningitis in pediatric patients is controversial. Two experts debated this topic at the 1993 meeting of the Infectious Diseases Society of America. Both experts agreed that for management of Haemophilus influenzae meningitis, dexamethasone significantly reduced sensorineural hearing loss and probably reduced other long-term sequelae. Because relatively few patients with pneumococcal and meningococcal meningitis have been studied, no conclusions could be reached regarding the effectiveness of dexamethasone. Dr. Urs Schaad emphasized the impressive anti-inflammatory effects of dexamethasone in experimental pneumococcal meningitis and the lack of any adverse events when given to children for 2 or 4 days. He recommended routine use of dexamethasone in treating pediatric patients with bacterial meningitis. Dr. Sheldon Kaplan expressed concern regarding the effectiveness of steroids in treating pneumococcal meningitis, especially when penicillin-resistant and cephalosporin-resistant isolates are present, and he addressed the question of the long-term effects of administration of dexamethasone in children with viral meningitis. He advised against the routine use of dexamethasone for non-H. influenzae meningiti
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