182 research outputs found
Algorithm for detecting the latent mastitis state of animals in a dairy farms on the based of data fusion from different types sensors
Основная статьяThe problem of latent mastitis identification in livestock enterprises is analyzed. The
necessity of automatizing the mastitis identification process is shown. Biological methods for
determining the presence of the disease are considered in the article. Common methods of data
fusion for the extraction of an informative trait is analyzed in the work. A new algorithm for
identifying mastitis in animals based on data fusion from the livestock enterprise sensors is
proposed. The developed algorithm as compared to the conventional method of determining
mastitis increases the accuracy of the disease's identification by 6.5 percent
Generation of Collisionless Shocks by Laser-Plasma Piston in Magnetised Background: Experiment “BUW”
Theoretical basis and main results of the first successful large-scale, Laser-Plasma experiment “BUW”, on generation of Collisionless Shock Wave in magnetised Background Plasma, are presented. Our classic approach is based on the action of so called Magnetic Laminar Mechanism (or Larmor coupling) for collisionless interaction between interpenetrating super-Alfvenic plasma flows of Laser-Plasma and Background in transverse magnetic field
Development of a Superconducting Differential Double Contour Interferometer
We study operation of a new device, the superconducting differential double
contour interferometer (DDCI), in application for the ultra sensitive detection
of magnetic flux and for digital read out of the state of the superconducting
flux qubit. DDCI consists of two superconducting contours weakly coupled by
Josephson Junctions. In such a device a change of the critical current and the
voltage happens in a step-like manner when the angular momentum quantum number
changes in one of the two contours. The DDCI may outperform traditional
Superconducting Quantum Interference Devices when the change of the quantum
number occurs in a narrow magnetic field region near the half of the flux
quantum due to thermal fluctuations, quantum fluctuations, or the switching a
loop segment in the normal state for a while by short pulse of an external
current.Comment: 11 pages, 8 figures, A version of the article has been accepted for
publication in Nano Letter
Proof of the multi-Regge form of QCD amplitudes with gluon exchanges in the NLA
The multi--Regge form of QCD amplitudes with gluon exchanges is proved in the
next-to-leading approximation. The proof is based on the bootstrap relations,
which are required for the compatibility of this form with the s-channel
unitarity. We show that the fulfillment of all these relations ensures the
Reggeized form of energy dependent radiative corrections order by order in
perturbation theory. Then we prove that all these relations are fulfilled if
several bootstrap conditions on the Reggeon vertices and trajectory hold true.
Now all these conditions are checked and proved to be satisfied.Comment: 15 page
A new variational approach to the stability of gravitational systems
We consider the three dimensional gravitational Vlasov Poisson system which
describes the mechanical state of a stellar system subject to its own gravity.
A well-known conjecture in astrophysics is that the steady state solutions
which are nonincreasing functions of their microscopic energy are nonlinearly
stable by the flow. This was proved at the linear level by several authors
based on the pioneering work by Antonov in 1961. Since then, standard
variational techniques based on concentration compactness methods as introduced
by P.-L. Lions in 1983 have led to the nonlinear stability of subclasses of
stationary solutions of ground state type.
In this paper, inspired by pioneering works from the physics litterature
(Lynden-Bell 94, Wiechen-Ziegler-Schindler MNRAS 88, Aly MNRAS 89), we use the
monotonicity of the Hamiltonian under generalized symmetric rearrangement
transformations to prove that non increasing steady solutions are local
minimizer of the Hamiltonian under equimeasurable constraints, and extract
compactness from suitable minimizing sequences. This implies the nonlinear
stability of nonincreasing anisotropic steady states under radially symmetric
perturbations
Dynamical stability of infinite homogeneous self-gravitating systems: application of the Nyquist method
We complete classical investigations concerning the dynamical stability of an
infinite homogeneous gaseous medium described by the Euler-Poisson system or an
infinite homogeneous stellar system described by the Vlasov-Poisson system
(Jeans problem). To determine the stability of an infinite homogeneous stellar
system with respect to a perturbation of wavenumber k, we apply the Nyquist
method. We first consider the case of single-humped distributions and show
that, for infinite homogeneous systems, the onset of instability is the same in
a stellar system and in the corresponding barotropic gas, contrary to the case
of inhomogeneous systems. We show that this result is true for any symmetric
single-humped velocity distribution, not only for the Maxwellian. If we
specialize on isothermal and polytropic distributions, analytical expressions
for the growth rate, damping rate and pulsation period of the perturbation can
be given. Then, we consider the Vlasov stability of symmetric and asymmetric
double-humped distributions (two-stream stellar systems) and determine the
stability diagrams depending on the degree of asymmetry. We compare these
results with the Euler stability of two self-gravitating gaseous streams.
Finally, we determine the corresponding stability diagrams in the case of
plasmas and compare the results with self-gravitating systems
Orbital stability of spherical galactic models
International audienceWe consider the three dimensional gravitational Vlasov Poisson system which is a canonical model in astrophysics to describe the dynamics of galactic clusters. A well known conjecture is the stability of spherical models which are nonincreasing radially symmetric steady states solutions. This conjecture was proved at the linear level by several authors in the continuation of the breakthrough work by Antonov in 1961. In a previous work, we derived the stability of anisotropic models under {\it spherically symmetric perturbations} using fundamental monotonicity properties of the Hamiltonian under suitable generalized symmetric rearrangements first observed in the physics litterature. In this work, we show how this approach combined with a {\it new generalized} Antonov type coercivity property implies the orbital stability of spherical models under general perturbations
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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