320 research outputs found
Nash equilibrium design in the interaction model of entities in the customs service system
The urgency of the analyzed issue is due to the importance of the use of economic-mathematical tools in the course of modeling the interaction of the entities in the customs service system that is necessary for the development of foreign economic activity (FEA) of any state. The purpose of the article is to identify effective strategies for the interaction between the participants of foreign trade activities with customs brokers. The leading method to the study of this issue is economic-mathematical modeling, allowing studying the process of making decisions while choosing the strategy of cooperation between the customs broker and his client. Results: the article suggests the mathematical model to optimize the management mechanisms of interaction between enterprises, engaged in foreign trade, and customs dealers. The data of this article may be useful in modeling interaction of the entities in the customs service system using the methods of game theory. The model of “customer - customs broker” is implemented as a bimatrix game. Assuming the noncooperativegame the authors solve the problem of finding Nash equilibrium in mixed strategies. © 2016 Fedorenko et al
Double difiusion in Ar-N2 Binary gas system at the constant value of temperature gradient
An experimental study of the diffusion-gravitational convection transition boundary in an Ar-N2 binary system at different pressures and a constant temperature gradient is performed. It is shown that the diflusion is replaced by the gravitational convection at a pressure p 0:5 MPa. In terms of the stability theory, a perturbation boundary line is determined, dividing the Rayleigh numbers plane into the regions of the diflusion and the convective mass transfer. The experimental data agree well with the theoretical values
Dynamic crossover in the global persistence at criticality
We investigate the global persistence properties of critical systems relaxing
from an initial state with non-vanishing value of the order parameter (e.g.,
the magnetization in the Ising model). The persistence probability of the
global order parameter displays two consecutive regimes in which it decays
algebraically in time with two distinct universal exponents. The associated
crossover is controlled by the initial value m_0 of the order parameter and the
typical time at which it occurs diverges as m_0 vanishes. Monte-Carlo
simulations of the two-dimensional Ising model with Glauber dynamics display
clearly this crossover. The measured exponent of the ultimate algebraic decay
is in rather good agreement with our theoretical predictions for the Ising
universality class.Comment: 5 pages, 2 figure
Critical Behaviour of 3D Systems with Long-Range Correlated Quenched Defects
A field-theoretic description of the critical behaviour of systems with
quenched defects obeying a power law correlations for
large separations is given. Directly for three-dimensional systems
and different values of correlation parameter a
renormalization analysis of scaling function in the two-loop approximation is
carried out, and the fixed points corresponding to stability of the various
types of critical behaviour are identified. The obtained results essentially
differ from results evaluated by double - expansion. The
critical exponents in the two-loop approximation are calculated with the use of
the Pade-Borel summation technique.Comment: Submitted to J. Phys. A, Letter to Editor 9 pages, 4 figure
Field theory conjecture for loop-erased random walks
We give evidence that the functional renormalization group (FRG), developed
to study disordered systems, may provide a field theoretic description for the
loop-erased random walk (LERW), allowing to compute its fractal dimension in a
systematic expansion in epsilon=4-d. Up to two loop, the FRG agrees with
rigorous bounds, correctly reproduces the leading logarithmic corrections at
the upper critical dimension d=4, and compares well with numerical studies. We
obtain the universal subleading logarithmic correction in d=4, which can be
used as a further test of the conjecture.Comment: 5 page
On the Possibility of the Detection of Extinct Radio Pulsars
We explore the possibilities for detecting pulsars that have ceased to
radiate in the radio band. We consider two models: the model with hindered
particle escape from the pulsar surface (first suggested by Ruderman and
Sutherland 1975) and the model with free particle escape (Arons 1981; Mestel
1999). In the model with hindered particle escape, the number of particles that
leave the pulsar magnetosphere is small and their radiation cannot be detected
with currently available instruments. At the same time, for the free particle
escape model, both the number of particles and the radiation intensity are high
enough for such pulsars to be detectable with the presently available receivers
such as GLAST and AGILE spacecrafts. It is also possible that extinct radio
pulsars can be among the unidentified EGRET sources.Comment: 5 pages, 1 figure corrected version of the paper that was published
in Astronomy Letter
Self-consistent solution of Kohn-Sham equations for infinitely extended systems with inhomogeneous electron gas
The density functional approach in the Kohn-Sham approximation is widely used
to study properties of many-electron systems. Due to the nonlinearity of the
Kohn-Sham equations, the general self-consistence searching method involves
iterations with alternate solving of the Poisson and Schr\"{o}dinger equations.
One of problems of such an approach is that the charge distribution renewed by
means of the Schr\"{o}dinger equation solution does not conform to boundary
conditions of Poisson equation for Coulomb potential. The resulting instability
or even divergence of iterations manifests itself most appreciably in the case
of infinitely extended systems. The published attempts to deal with this
problem are reduced in fact to abandoning the original iterative method and
replacing it with some approximate calculation scheme, which is usually
semi-empirical and does not permit to evaluate the extent of deviation from the
exact solution. In this work, we realize the iterative scheme of solving the
Kohn-Sham equations for extended systems with inhomogeneous electron gas, which
is based on eliminating the long-range character of Coulomb interaction as the
cause of tight coupling between charge distribution and boundary conditions.
The suggested algorithm is employed to calculate energy spectrum,
self-consistent potential, and electrostatic capacitance of the semi-infinite
degenerate electron gas bounded by infinitely high barrier, as well as the work
function and surface energy of simple metals in the jellium model. The
difference between self-consistent Hartree solutions and those taking into
account the exchange-correlation interaction is analyzed. The case study of the
metal-semiconductor tunnel contact shows this method being applied to an
infinitely extended system where the steady-state current can flow.Comment: 38 pages, 9 figures, to be published in ZhETF (J. Exp. Theor. Phys.
On the nature of Seyfert galaxies with high [OIII]5007 blueshifts
We have studied the properties of Seyfert galaxies with high [OIII]5007
blueshifts (`blue outliers'), originally identified because of their strong
deviation from the M_BH - sigma relation of normal, narrow-line Seyfert 1
(NLS1) and broad-line Seyfert 1 (BLS1) galaxies. These blue outliers turn out
to be important test-beds for models of the narrow-line region (NLR), for
mechanisms of driving large-scale outflows, for links between NLS1 galaxies and
radio galaxies, and for orientation-dependent NLS1 models. We report the
detection of a strong correlation of line blueshift with ionization potential
in each galaxy, including the measurement of coronal lines with radial
velocities up to 500--1000 km/s. All [OIII] blue outliers have narrow widths of
their broad Balmer lines and high Eddington ratios. While the presence of
non-shifted low-ionization lines signifies the presence of a classical outer
quiescent NLR in blue outliers, we also report the absence of any second,
non-blueshifted [OIII] component from a classical inner NLR. These results
place tight constraints on NLR models. We favor a scenario in which the NLR
clouds are entrained in a decelerating wind which explains the strong
stratification and the absence of a zero-blueshift inner NLR of blue outliers.
The origin of the wind remains speculative at this time (collimated radio
plasma, thermal winds, radiatively accelerated clouds). It is perhaps linked to
the high Eddington ratios of blue outliers. Similar, less powerful winds could
be present in all Seyfert galaxies, but would generally only affect the coronal
line region (CLR), or level off even before reaching the CLR. Similarities
between blue outliers in NLS1 galaxies and (compact) radio sources are briefly
discussed.Comment: ApJ in press (scheduled for June 20 issue); incl. 4 colour figures.
This, and related paper showing that NLS1 galaxies follow the M-sigma
relation based on [SII], is also available at
http://www.xray.mpe.mpg.de/~skomossa
Orbital glass and spin glass states of 3He-A in aerogel
Glass states of superfluid A-like phase of 3He in aerogel induced by random
orientations of aerogel strands are investigated theoretically and
experimentally. In anisotropic aerogel with stretching deformation two glass
phases are observed. Both phases represent the anisotropic glass of the orbital
ferromagnetic vector l -- the orbital glass (OG). The phases differ by the spin
structure: the spin nematic vector d can be either in the ordered spin nematic
(SN) state or in the disordered spin-glass (SG) state. The first phase (OG-SN)
is formed under conventional cooling from normal 3He. The second phase (OG-SG)
is metastable, being obtained by cooling through the superfluid transition
temperature, when large enough resonant continuous radio-frequency excitation
are applied. NMR signature of different phases allows us to measure the
parameter of the global anisotropy of the orbital glass induced by deformation.Comment: 7 pages, 6 figures, Submitted to Pis'ma v ZhETF (JETP Letters
Rare region effects at classical, quantum, and non-equilibrium phase transitions
Rare regions, i.e., rare large spatial disorder fluctuations, can
dramatically change the properties of a phase transition in a quenched
disordered system. In generic classical equilibrium systems, they lead to an
essential singularity, the so-called Griffiths singularity, of the free energy
in the vicinity of the phase transition. Stronger effects can be observed at
zero-temperature quantum phase transitions, at nonequilibrium phase
transitions, and in systems with correlated disorder. In some cases, rare
regions can actually completely destroy the sharp phase transition by smearing.
This topical review presents a unifying framework for rare region effects at
weakly disordered classical, quantum, and nonequilibrium phase transitions
based on the effective dimensionality of the rare regions. Explicit examples
include disordered classical Ising and Heisenberg models, insulating and
metallic random quantum magnets, and the disordered contact process.Comment: Topical review, 68 pages, 14 figures, final version as publishe
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