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Izmailov A.F.,Moscow State University | Kurennoy A.S.,Tambov State University | Solodov M.V.,IMPAInstitute Matematica Pura e Aplicada
Mathematical Programming | Year: 2017

We show that if the equation mapping is 2-regular at a solution in some nonzero direction in the null space of its Jacobian (in which case this solution is critical; in particular, the local Lipschitzian error bound does not hold), then this direction defines a star-like domain with nonempty interior from which the iterates generated by a certain class of Newton-type methods necessarily converge to the solution in question. This is despite the solution being degenerate, and possibly non-isolated (so that there are other solutions nearby). In this sense, Newtonian iterates are attracted to the specific (critical) solution. Those results are related to the ones due to A. Griewank for the basic Newton method but are also applicable, for example, to some methods developed specially for tackling the case of potentially non-isolated solutions, including the Levenberg–Marquardt and the LP-Newton methods for equations, and the stabilized sequential quadratic programming for optimization. © 2017 Springer-Verlag Berlin Heidelberg and Mathematical Optimization Society

Rodimtsev A.S.,Tambov State University | Ermolaev A.I.,Russian Academy of Sciences
Biology Bulletin | Year: 2016

The dynamics of body mass growth were studied in nestlings of 22 semialtricial and altricial bird species based on materials collected in seven regions of Russia in the years 1976–2013. The bird species belong to four orders and 13 families. The results of the study indicate the nonuniform growth of nestlings in different bird species. Of the species investigated, only seven were found to reach or exceed the mass of adult birds. Over the nestling period, the nestlings of open-nesting species, such as the hooded crow (Corvus cornix), rook (Corvus frugilegus), magpie (Pica pica), fieldfare (Turdus pilaris), song thrush (Turdus philomelos), and goldfinch (Carduelis carduelis), do not reach the weight of adult birds and their growth continues after they leave the nest. In closed-nesting species, only the nestlings of the barn swallow (Hirundo rustica) reach or exceed the definitive mass, whereas the nestlings of the jackdaw (Corvus monedula), starling (Sturnus vulgaris), wryneck (Jynx torquilla), tree sparrow (Passer montanus), and great tit (Parus major) continue to grow after leaving the nest. The body mass of birds on the day of their hatching and before their departure from the nests and the mass of adult birds depend on the nesting type, duration of the nestling period, size groups of species, and their definitive size. The average specific growth rate of body mass and its maximum values for different species are also associated with these factors. The maximum specific growth rate in small-sized and medium-sized bird species was observed on the 0–1st days of life; in large bird species, on the 2nd–4th days. The specific growth rate did not depend on the type of nesting, but it was inversely related to the duration of the nestling period and the definitive sizes of birds. © 2016, Pleiades Publishing, Inc.

Malaschonok G.I.,Tambov State University
Programming and Computer Software | Year: 2017

In this paper, we describe general characteristics of the MathPartner computer algebra system (CAS) and Mathpar programming language thereof. MathPartner can be used for scientific and engineering calculations, as well as in high schools and universities. It allows one to carry out both simple calculations (acting as a scientific calculator) and complex calculations with large-scale mathematical objects. Mathpar is a procedural language; it supports a large number of elementary and special functions, as well as matrix and polynomial operators. This service allows one to build function images and animate them. MathPartner also makes it possible to solve some symbolic computation problems on supercomputers with distributed memory. We highlight main differences of MathPartner from other CASs and describe the Mathpar language along with the user service provided. © 2017, Pleiades Publishing, Ltd.

Vigdorovich V.I.,Tambov State Technical University | Tsygankova L.E.,Tambov State University | Balybin D.V.,Tambov State University
Journal of Electroanalytical Chemistry | Year: 2011

Connection between kinetics of hydrogen evolution reaction on iron and concentrations of hydrogen ions (at constant ionic strength equal to 1) and guanidine has been studied in the aqueous (hydrogen ions discharge is rate determining stage) and ethylene glycol + water (10 wt.% H2O, recombination of adsorbed hydrogen is rate determining stage) acidic chloride solutions. Guanidine (NH2)2CNH is entirely protonated in the studied conditions. But in the aqueous solutions, a rate of its cathode reduction is insignificant and main proton donor is H3O +-ions. In ethylene glycol solutions a rate of guanidine ions discharge is larger, that though does not determine a nature of rate determining stage. Observed regularities are compared with hydrogen diffusion rate i H through the carbon steel membrane. iH value insignificantly depends on guanidine concentration in aqueous media, especially in the range of its small concentrations. In the ethylene glycol media such a dependence is considerable up to 1 mM guanidine concentration. Nature of rate determining stage of hydrogen evolution reaction does not determine a character of iH = f(CHCl) and iH = f(C guanidine) dependences. © 2011 Elsevier B.V. All rights reserved.

Dmitrievskiy A.A.,Tambov State University
Russian Physics Journal | Year: 2013

Regularities of changes in the mechanical properties (micro- or nanohardness, fracture toughness at indentation, and steady-state creep rate) and electrical characteristics (Hall constant, conductivity, and concentration of electrically active defects) of silicon single crystals under low-dose (F < 1012cm-2) low-intensity (I ~ 106cm-2{bullet operator}s-1) beta-irradiation are described. The mechanism of nonmonotonic beta-induced softening of silicon is discussed. © 2013 Springer Science+Business Media New York.

Malaschonok G.,Tambov State University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

The deterministic recursive pivot-free algorithms for computing the generalized Bruhat decomposition of the matrix in the field and for the computation of the inverse matrix are presented. This method has the same complexity as algorithm of matrix multiplication, and it is suitable for the parallel computer systems. © 2010 Springer-Verlag Berlin Heidelberg.

Zhigachev A.O.,Tambov State University
Review of Scientific Instruments | Year: 2013

The effect of specimen surface curvature on profiles of asymmetric X-ray diffraction peaks obtained using the Bragg-Brentano geometry with a position sensitive detector (PSD) was studied. Asymmetric diffraction peaks were experimentally obtained from cylindrical surfaces with controlled curvature. Peaks were collected for a set of curvature radii, diffraction angles, and materials. A mathematical approach and a computer model for calculations of peak profiles were developed: a general method for computation of peak profiles is consideration of diffraction cones intersection with the PSD surface. Effects of axial and radial divergence, finite sample size, and local surface tilt were included in the model. Calculated peak profiles agree with reflections obtained experimentally at a wide range of curvature radii and diffraction angle values. Computation of important characteristics such as the peak centroid and change in position of the maximum and full-width-half-maximum is provided. © 2013 AIP Publishing LLC.

Malaschonok G.,Tambov State University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

Deterministic recursive algorithms for the computation of generalized Bruhat decomposition of the matrix in commutative domain are presented. This method has the same complexity as the algorithm of matrix multiplication. © 2013 Springer International Publishing.

Shibkov A.A.,Tambov State University | Zolotov A.E.,Tambov State University
Crystallography Reports | Year: 2011

The early stages of development of Lüders band in recrystallized 5456 alloy have been investigated by the method of acoustic emission and synchronously by high-speed video tapping with a rate of 500 frames/s. It is established that the first acoustic pulse indicates the instant that the first band of localized deformation nucleates (which initiates the formation of the complex structure of the Lüders front) and is in this context an acoustic precursor to the loss of deformation stability of the alloy. © 2011 Pleiades Publishing, Ltd.

Dmitrievskii A.A.,Tambov State University
Technical Physics Letters | Year: 2014

The phase transition from a diamond-like crystalline lattice of the Si-I phase to the β-tin type structure of the Si-II phase has been studied by measuring electric resistance under an indenter incorporated into a narrow (d ≈ 2 μm) crevice between metal contacts. It was established that the relative volume fraction of the metalized Si-II phase formed during indentation decreases under the action of a low dose (fluence F = 3.24 × 1010 cm-2) of low-intensity (I = 1.8 × 105 cm-2 s-1) beta radiation. © 2014 Pleiades Publishing, Ltd.

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