Pavlovskiy Posad, Russia
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Semin V.,Samara National Research University | Petruccione F.,University of KwaZulu - Natal
Journal of Physics A: Mathematical and Theoretical | Year: 2016

The not necessarily unitary evolution operator of a finite dimensional quantum system is studied with the help of a projection operators technique. Applying this approach to the Schrödinger equation allows the derivation of an alternative expression for the evolution operator, which differs from the traditional chronological exponent. An appropriate choice of projection operators results in the possibility of studying the diagonal and non-diagonal elements of the evolution operator separately. The suggested expression implies a particular form of perturbation expansion, which leads to a new formula for the short time dynamics. The new kind of perturbation expansion can be used to improve the accuracy of the usual chronological exponent significantly. The evolution operator for any arbitrary time can be efficiently recovered using the semigroup properties. The method is illustrated by two examples, namely the dynamics of a three-level system in two nonresonant laser fields and the calculation of the partition function of a finite XY-spin chain. © 2016 IOP Publishing Ltd.


We proposed a method of the formation of structures in materials by laser treatment aimed to enhance the performance characteristics of aircraft engine parts. The experimental study was conducted using a high-power gas CO2 laser ROFIN DC 010. Using an optical system comprising a focusing diffractive optical element, the laser beam was focused into a focal line with the maximum power density in its center. Tests on the joint deformation of the coating and substrate were conducted. We also determined the running-in ability of the ANB + NA-67 coating following the cut-in of an opposite element. It was found that the laser treatment of the sublayer enabled the bending angle to be increased while avoiding cracking and delamination of the coating. © 2016, Institution of Russian Academy of Sciences. All rights reserved.


Vasilievich P.O.,Samara National Research University
Computer Optics | Year: 2016

We describe methods, algorithms and means of narrow-angle spectral and tomography diagnostics of parameters of plasma flows such as spatial local temperature distribution and concentration for small-size plasma ejectors (engines for orientation in space and thrusters). © 2016, Institution of Russian Academy of Sciences. All rights reserved.


Aslanov V.S.,Samara National Research University | Ledkov A.S.,Samara National Research University
Journal of Guidance, Control, and Dynamics | Year: 2016

Conical-shaped reentry capsules with a spherical bottom and a displaced center of mass from the axis of symmetry are widely used in astronautics for payload delivery. In the case of control-system breakage, modern reentry capsules allow a successful landing to be carried out in an uncontrolled mode. At the same time, the aerodynamic features of this particular shape create preconditions for chaotic motion. This can leadtoanoverturnofthe capsule, thus creating the risk of an accident. This article explores uncontrolled descent of the reentry capsule, with slight asymmetry, into the atmosphere. The system of differential equations describing uncontrollable descent of an asymmetric capsule in the atmosphere was recorded. Fast and slow variables were introduced. A simplified system of equations was obtained, describing the change of the spatial angle of attack. It was shown that chaotic motion can occur during the uncontrolled descent in the atmosphere. The algorithm of damping coefficient selection was developed on the basis of Melnikov's method. Its application allows for the elimination of chaosinthe whole descent trajectory, thus increasing the system reliability. Copyright © 2016 by the American Institute of Aeronautics and Astronautics,.


Akhmetshina T.G.,Samara National Research University | Blatov V.A.,Samara National Research University
Structural Chemistry | Year: 2016

In this work, we apply the nanocluster method to analyze all known intermetallics containing two-shell nanoclusters with icosahedral core. Using the ToposPro program package, we have found all intermetallics with two-shell nanoclusters as building units or local configurations. We have analyzed in more details Bergman, Bergman-based and two types of icosahedral-based 63-atom nanoclusters, which have been discovered for the first time using the ToposPro nanoclustering procedure. Simplification of the nanocluster representations to their underlying nets revealed widespread topologies such as body-centered cubic (bcu-x), face-centered cubic (fcu) and hexagonal primitive (hex). We have performed topological analysis of these intermetallics in terms of local and overall binding of clusters. The statistical data on the chemical composition of the nanoclusters are presented; the ways of local binding of nanoclusters and the topology of the corresponding underlying nets are determined and classified. © 2016 Springer Science+Business Media New York


Fedoseev V.,Russian Academy of Sciences | Mishkina E.,Samara National Research University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

In this paper we propose a method for automatic selection of relevant filter responses which are used for extraction of latent images from printed documents containing means of protection. In other words, it constitutes a part of the latent image extraction technique developed earlier, which is based on convolving an analyzing document image with an adaptively constructed Gabor filter bank. Previously selection a set of relevant filter responses was performed manually. Therefore the motivation of this paper is to design an automatic procedure for this stage. The proposed procedure consists in joint classification of both magnitude and phase parts of filter responses using specific feature sets. The results of experimental investigations showing high precision of the method are given. © Springer International Publishing AG 2016.


Kuznetsov A.,Samara National Research University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Copy-move attack is one of the most popular digital image forgery attacks. The main problem is that existing studies do not provide high detection accuracy with low computational complexity. High complexity of existing feature based solutions makes impossible to use them for large remote sensing snapshots analysis. In this paper there is proposed a copy-move detection algorithm based on perceptual hash value calculation. Hash values are evaluated using the result of binary gradient contours computation. The proposed solution showed high detection accuracy and low computational complexity for copy-move detection in remote sensing data. © Springer International Publishing AG 2016.


Blatov V.A.,Samara National Research University
Structural Chemistry | Year: 2016

A method for analysis of geometrical and topological properties of crystal structures, which contain one-periodic (chain-like) structural units, is proposed and implemented as a computer procedure into the program package ToposPro. The method is based on representation of the set of parallel chains as two kinds of two-periodic nets: rod net, which characterizes the way of linking the chains with each other, and rod packing net, which describes the method of spatial arrangement of the chains irrespective of their interconnections. The geometrical (Domains method) and topological criteria are formulated to construct rod nets and rod packing nets from the initial crystallographic data. It is shown that rod packing net formalizes earlier classifications of rod packings in crystals. Examples are presented, which demonstrate the applications of the method to one-periodic coordination polymers, metal–organic frameworks, and hydrogen-bonded molecular crystals. © 2016 Springer Science+Business Media New York


Frolov V.,Samara National Research University
MATEC Web of Conferences | Year: 2016

The paper presents an overview of results for wing-body interference, obtained by the author for varied wing-body combinations. The lift-curve slopes of the wing-body combinations are considered. In this paper a discrete vortices method (DVM) and 2D potential model for cross-flow around fuselage are used. The circular and elliptical cross-sections of the fuselage and flat wings of various forms are considered. Calculations showed that the value of the lift-curve slopes of the wing-body combinations may exceed the same value for an isolated wing. This result confirms an experimental data obtained by other authors earlier. Within a framework of the used mathematical models the investigations to optimize the wing-body combination were carried. The present results of the optimization problem for the wing-body combination allowed to select the optimal geometric characteristics for configuration to maximize the values of the lift-curve slopes of the wing-body combination. It was revealed that maximums of the lift-curve slopes for the optimal mid-wing configuration with elliptical cross-section body had a sufficiently large relative width of the body (more than 30% of the span wing). © 2016 The Authors, published by EDP Sciences.


Blatov V.A.,Samara National Research University
Structural Chemistry | Year: 2016

A short introduction is given to the special issue dedicated to Academician Vladimir Ya. Shevchenko on the occasion of his 75th birthday. The guest editor tells briefly about his first meeting and subsequent long, close, and fruitful collaboration with Prof. Shevchenko. The main scientific interests and achievements of Prof. Shevchenko are outlined. © 2016 Springer Science+Business Media New York

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