1,406 research outputs found
Strain sensing based on radiative emission-absorption mechanism using dye-doped polymer optical fiber
A stress sensor based on a dye-doped polymeric optical fiber is able to detect stress by simple comparison of two luminescence peaks from a pair of energy transfer organic dyes. Coumarin 540A (donor) and Rhodamine 6G (acceptor) were doped in the core and cladding of the fiber, respectively. For various laser wavelengths, the change in the near-field pattern and visible emission spectrum upon variation in the fiber bending diameter was evaluated. From a comparison with a low-numerical-aperture fiber, it is shown that the sensitivity of the sensor is controllable by optimization of the waveguide parameters
On the possibility of generating a 4-neutron resonance with a {\boldmath } isospin 3-neutron force
We consider the theoretical possibility to generate a narrow resonance in the
four neutron system as suggested by a recent experimental result. To that end,
a phenomenological three neutron force is introduced, in addition to a
realistic interaction. We inquire what should be the strength of the
force in order to generate such a resonance. The reliability of the
three-neutron force in the channel is exmined, by analyzing its
consistency with the low-lying states of H, He and Li and the
scattering.
The {\it ab initio} solution of the Schr\"{o}dinger equation is obtained
using the complex scaling method with boundary conditions appropiate to the
four-body resonances. We find that in order to generate narrow resonant
states a remarkably attractive force in the channel is required.Comment: 11 pages, 11 figures, minor change, published version, to be
published in Physical Review
Deformations of Maxwell Superalgebras and Their Applications
We describe the Lie algebra deformations of D=4 Maxwell superalgebra that was
recently introduced as the symmetry algebra of a kappa-symmetric massless
superparticle in a supersymmetric constant electromagnetic background. Further
we introduce the D=3 Maxwell superalgebra and present all its possible
deformations. Finally the deformed superalgebras are used to derive via a
contraction procedure the complete set of Casimir operators for D=4 and D=3
Maxwell superalgebras.Comment: 30 pages, 1 figure, Comments and a reference adde
Deformed Maxwell Algebras and their Realizations
We study all possible deformations of the Maxwell algebra. In D=d+1\neq 3
dimensions there is only one-parameter deformation. The deformed algebra is
isomorphic to so(d+1,1)\oplus so(d,1) or to so(d,2)\oplus so(d,1) depending on
the signs of the deformation parameter. We construct in the dS (AdS) space a
model of massive particle interacting with Abelian vector field via non-local
Lorentz force. In D=2+1 the deformations depend on two parameters b and k. We
construct a phase diagram, with two parts of the (b,k) plane with so(3,1)\oplus
so(2,1) and so(2,2)\oplus so(2,1) algebras separated by a critical curve along
which the algebra is isomorphic to Iso(2,1)\oplus so(2,1). We introduce in
D=2+1 the Volkov-Akulov type model for a Abelian Goldstone-Nambu vector field
described by a non-linear action containing as its bilinear term the free
Chern-Simons Lagrangean.Comment: 10 pages, Talk based on [1] in the XXV-th Max Born Symposium "Planck
Scale", held in Wroclaw 29.06-3.07.200
Relay Backpropagation for Effective Learning of Deep Convolutional Neural Networks
Learning deeper convolutional neural networks becomes a tendency in recent
years. However, many empirical evidences suggest that performance improvement
cannot be gained by simply stacking more layers. In this paper, we consider the
issue from an information theoretical perspective, and propose a novel method
Relay Backpropagation, that encourages the propagation of effective information
through the network in training stage. By virtue of the method, we achieved the
first place in ILSVRC 2015 Scene Classification Challenge. Extensive
experiments on two challenging large scale datasets demonstrate the
effectiveness of our method is not restricted to a specific dataset or network
architecture. Our models will be available to the research community later.Comment: Technical report for our submissions to the ILSVRC 2015 Scene
Classification Challenge, where we won the first plac
Super-Weyl Invariant 2D Supergravity, Anomaly and WZ Action
We present a candidate of anomaly and Wess Zumino action of the two
dimensional supergravity coupling with matters in a super-Weyl invariant
regularization. It is a generalization of the Weyl and the area preserving
\Diff invariant formulation of two dimensional gravity theory.Comment: 9 pages, Late
Quantum limits of super-resolution in reconstruction of optical objects
We investigate analytically and numerically the role of quantum fluctuations
in reconstruction of optical objects from diffraction-limited images. Taking as
example of an input object two closely spaced Gaussian peaks we demonstrate
that one can improve the resolution in the reconstructed object over the
classical Rayleigh limit. We show that the ultimate quantum limit of resolution
in such reconstruction procedure is determined not by diffraction but by the
signal-to-noise ratio in the input object. We formulate a quantitative measure
of super-resolution in terms of the optical point-spread function of the
system.Comment: 23 pages, 7 figures. Submitted to Physical Review A e-mail:
[email protected]
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