45 research outputs found
Algorithm for individual learning content formation in automated machine learning system
The study describes the algorithms used in the formation of individual learning content which can be used in machine learning. The algorithm for generating educational content based on the input test procedure, thereby reducing the number of elementary units of knowledge in the educational conten
ETALON-1,-2 center of mass correction and array reflectivity
Center of mass correction to be applied to measured ranges to the ETALON 1 and 2 satellites is considered. Numerical values of the correction and reflectivity from the retroreflector array are computed. The variations of these values with satellite orientation are investigated
Dynamics of risk degree of innovation-driven growth at higher education institutions
In this article, the analysis of dynamics of risk degree of innovation-driven growth at higher education institutions is discussed. The survey has been employed in this paper and the data analyzed by SPSS software. Results revealed that the resulting risks are regularly encountered in a modern Russian higher educational institution: inability to provide necessary financial support for educational activities; inability to provide required modern material and technical basis; challenges and failures in collaboration with enterprises for organizing practical training for students and the absence of practical training programs at the university. It is also indicated that the risk event might lead to different results: negative, positive, or nul
Conservation laws of semidiscrete canonical Hamiltonian equations
There are many evolution partial differential equations which can be cast
into Hamiltonian form. Conservation laws of these equations are related to
one-parameter Hamiltonian symmetries admitted by the PDEs. The same result
holds for semidiscrete Hamiltonian equations. In this paper we consider
semidiscrete canonical Hamiltonian equations. Using symmetries, we find
conservation laws for the semidiscretized nonlinear wave equation and
Schrodinger equation.Comment: 19 pages, 2 table
Kinetics of exciton photoluminescence in type-II semiconductor superlattices
The exciton decay rate at a rough interface in type-II semiconductor
superlattices is investigated. It is shown that the possibility of
recombination of indirect excitons at a plane interface essentially affects
kinetics of the exciton photoluminescence at a rough interface. This happens
because of strong correlation between the exciton recombination at the plane
interface and at the roughness. Expressions that relate the parameters of the
luminescence kinetics with statistical characteristics of the rough interface
are obtained. The mean height and length of roughnesses in GaAs/AlAs
superlattices are estimated from the experimental data.Comment: 3 PostScript figure
Globular Clusters as Candidates for Gravitational Lenses to Explain Quasar-Galaxy Associations
We argue that globular clusters (GCs) are good candidates for gravitational
lenses in explaining quasar-galaxy associations. The catalog of associations
(Bukhmastova 2001) compiled from the LEDA catalog of galaxies (Paturel 1997)
and from the catalog of quasars (Veron-Cetty and Veron 1998) is used. Based on
the new catalog containing 8382 pairs, we show that one might expect an
increased number of GCs around irregular galaxies of types 9 and 10 from the
hypothesis that distant compact sources are gravitationally lensed by GCs in
the halos of foreground galaxies. The King model is used to determine the
central surface densities of 135 GCs in the Milky Way. The distribution of GCs
in central surface density was found to be lognormal.Comment: 22 pages, 4 figure
Bose--Einstein solitons in highly asymmetric traps
We obtain analytic solutions to the Gross-Pitaevskii equation with negative
scattering length in highly asymmetric traps. We find that in these traps the
Bose--Einstein condensates behave like quasiparticles and do not expand when
the trapping in one direction is eliminated. The results can be applicable to
the control of the motion of Bose--Einstein condensates.Comment: 12 pages, Latex, Figures available under request on
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Extended parametric resonances in nonlinear Schrodinger systems
We study an example of exact parametric resonance in a extended system ruled
by nonlinear partial differential equations of nonlinear Schr\"odinger type. It
is also conjectured how related models not exactly solvable should behave in
the same way. The results have applicability in recent experiments in
Bose-Einstein condensation and to classical problems in Nonlinear Optics.Comment: 1 figur
Recovery of Dirac system from the rectangular Weyl matrix function
Weyl theory for Dirac systems with rectangular matrix potentials is
non-classical. The corresponding Weyl functions are rectangular matrix
functions. Furthermore, they are non-expansive in the upper semi-plane. Inverse
problems are treated for such Weyl functions, and some results are new even for
the square Weyl functions. High energy asymptotics of Weyl functions and
Borg-Marchenko type uniqueness results are derived too