2,419 research outputs found
Equivariant Giambelli and determinantal restriction formulas for the Grassmannian
The main result of the paper is a determinantal formula for the restriction
to a torus fixed point of the equivariant class of a Schubert subvariety in the
torus equivariant integral cohomology ring of the Grassmannian. As a corollary,
we obtain an equivariant version of the Giambelli formula.Comment: 16 pages, 3 figures, LaTex, uses epsfig and psfrag; for the revised
version: title changed; Proof of Theorem 3 changed; 3 references added and 1
deleted; other minor change
Semi-supervised and Active-learning Scenarios: Efficient Acoustic Model Refinement for a Low Resource Indian Language
We address the problem of efficient acoustic-model refinement (continuous
retraining) using semi-supervised and active learning for a low resource Indian
language, wherein the low resource constraints are having i) a small labeled
corpus from which to train a baseline `seed' acoustic model and ii) a large
training corpus without orthographic labeling or from which to perform a data
selection for manual labeling at low costs. The proposed semi-supervised
learning decodes the unlabeled large training corpus using the seed model and
through various protocols, selects the decoded utterances with high reliability
using confidence levels (that correlate to the WER of the decoded utterances)
and iterative bootstrapping. The proposed active learning protocol uses
confidence level based metric to select the decoded utterances from the large
unlabeled corpus for further labeling. The semi-supervised learning protocols
can offer a WER reduction, from a poorly trained seed model, by as much as 50%
of the best WER-reduction realizable from the seed model's WER, if the large
corpus were labeled and used for acoustic-model training. The active learning
protocols allow that only 60% of the entire training corpus be manually
labeled, to reach the same performance as the entire data
Growth Stress Induced Tunability of Dielectric Constant in Thin Films
It is demonstrated here that growth stress has a substantial effect on the
dielectric constant of zirconia thin films. The correct combination of
parameters - phase, texture and stress - is shown to yield films with high
dielectric constant and best reported equivalent oxide thickness of 0.8 nm. The
stress effect on dielectric constant is twofold, firstly, by the effect on
phase transitions and secondly by the effect on interatomic distances. We
discuss and explain the physical mechanisms involved in the interplay between
the stress, phase changes and the dielectric constant in detail.Comment: 11 pages, 5 figure
RSK bases and Kazhdan-Lusztig cells
From the combinatorial characterizations of the right, left, and two-sided
Kazhdan-Lusztig cells of the symmetric group, 'RSK bases' are constructed for
certain quotients by two-sided ideals of the group ring and the Hecke algebra.
Applications to invariant theory, over various base rings, of the general
linear group and representation theory of the symmetric group are discussed.Comment: 31 pages, latex; version 2 differs substantially in exposition from
version 1; for version 3: added important references, corrected typos, added
comments suggested by referee, results unchange
Inverse beta decay reaction in Th and U fission antineutrino flux
Energy spectra of antineutrinos coming from Th and U
neutron-induced fission are calculated, relevant inverse beta decay
positron spectra and total cross sections are
found. This study is stimulated by a hypothesis that a self-sustained nuclear
chain reaction is burning at the center of the Earth ("Georeactor"). The
Georeactor, according to the author of this idea, provides energy necessary to
sustain the Earth's magnetic field. The Georeactor's nuclear fuel is U
and, probably, Th and U. Results of present study may appear to
be useful in future experiments aimed to test the Georector hypothesis and to
estimate its fuel components as a part of developments in geophysics and
astrophysics based on observations of low energy antineutrinos in Nature.Comment: 6 pages in LaTeX and 2 ps figures. Submitted to Physics of Atomic
Nucle
Urticaria - some observations
Urticaria has been known from antiquity. The disorder was
known to the Arabs as essera and it has found a place in the
writings of Cesius (circa 30 BC–45 AD). Although the condition
was recognised as an entity, its cause was a mystery to the
physicians of those times. It was initially thought to be a
manifestation of idiosyncrasy and later believed to be a form
of neuroses. However, now the pathophysiological basis of
urticaria is well understood. The development of antihistamine
group of drugs, paved the way for the management of urticaria
Numerical bifurcation study of superconducting patterns on a square
This paper considers the extreme type-II Ginzburg-Landau equations that model
vortex patterns in superconductors. The nonlinear PDEs are solved using
Newton's method, and properties of the Jacobian operator are highlighted.
Specifically, it is illustrated how the operator can be regularized using an
appropriate phase condition. For a two-dimensional square sample, the numerical
results are based on a finite-difference discretization with link variables
that preserves the gauge invariance. For two exemplary sample sizes, a thorough
bifurcation analysis is performed using the strength of the applied magnetic
field as a bifurcation parameter and focusing on the symmetries of this system.
The analysis gives new insight in the transitions between stable and unstable
states, as well as the connections between stable solution branches.Comment: 31 page
Unique Factorization For Tensor Products of Parabolic Verma Modules
Let be a symmetrizable Kac-Moody Lie algebra with Cartan
subalgebra . We prove a unique factorization property for tensor
products of parabolic Verma modules. More generally, we prove unique
factorization for products of characters of parabolic Verma modules when
restricted to certain subalgebras of . These include fixed point
subalgebras of under subgroups of diagram automorphisms of
and twisted graph automorphisms in the affine case.Comment: 20 page
Current Status of Radioisotope Applications in Defence
Reviews the current status of radioisotope applications in Defence- R&D Establishments, Defence Inspectorates, Ordnance Factories, Public Sector Undertakings under the Defence Ministry, Army, Navy and Air Force Establishments and Military Hospitals. It also lists the users of film badge service in Defence. Training programmes in radioisotope applications in Defence conducted by DRDO organisations have also been highlighted
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