Samara National Research University

Pavlovskiy Posad, Russia

Samara National Research University

Pavlovskiy Posad, Russia
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Sobolev V.,Samara National Research University
Journal of Physics: Conference Series | Year: 2017

The aim of the paper is to describe the special critical case in the theory of singularly perturbed optimal control problems. We reduce the original singularly perturbed problem to a regularized one such that the existence of slow integral manifolds can be established by means of the standard theory. We illustrate our approach by an example of control problem. © Published under licence by IOP Publishing Ltd.


Shchepakina E.,Samara National Research University
Journal of Physics: Conference Series | Year: 2017

The paper deals with the problem of a construction of global stable/unstable slow integral manifolds of the singularly perturbed systems in critical cases. In addition to the well-known critical cases a novel scenario of the stability change of the slow integral manifold is considered. All three critical cases leading to the change of the stability are discussed via the Hindmarsh-Rose dynamic model. It is shown that the suitable choice of the additional parameters of the system yields the slow integral manifold with multiple change of its stability. © Published under licence by IOP Publishing Ltd.


Mezhenin A.V.,Samara National Research University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2017

The two-level generation model has been applied to analyze the dependence of power efficiency of chemical oxygen-iodine laser (COIL) and electric oxygen-iodine laser (EOIL) on three dimensionless similarity criteria: residence-to-extraction time ratio γd, gain-to-loss ratio ∏ and relaxation-to-excitation rate ratio Γ. Power efficiency is represented as the product of two factors - the medium extraction efficiency and the extraction efficiency of resonator - each being a function of the ∏. The dependences of the similarity criteria γd and ∏ optimal values on the kinetic and optical losses have been found. At low kinetic and optical losses, it is expedient to work with high values of γd and ∏ respectively. It has been found that maximum power efficiency is achieved when ∏=3-8 for COIL and ∏=9-17 for EOIL at the typical γd and optical losses rate. © 2017 SPIE.


Denisova A.,Samara National Research University
Communications in Computer and Information Science | Year: 2017

This article continues studies of probability anomaly detector method which was presented in author’s previous works. Here two implementations of this method are introduced. The implementations are based on different vector quantization algorithms. Description of both algorithms and results of experimental research of their parameters are provided. Both implementations are compared with well known RX anomaly detector on synthetic hyperspectral images. © Springer International Publishing AG 2017.


Gorokhov A.V.,Samara National Research University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2017

Method of dynamical groups and approach of coherent states have used to calculate the squeezing and multiphoton correlations in spontaneous parametric down-conversion processes. Special case of twisted photons with orbital angular momentum is considered. © 2016 SPIE.


Matyunin S.A.,Samara National Research University
Procedia Engineering | Year: 2017

Structure, operating principle, theoretical provisions, experimental characteristics of fiber optic sensors for control of a bending in phalanxes of the anthropomorphous robot fingers, as well as principle of compensation for cross impact of adjacent measuring channels are considered. Linearization algorithm of positional characteristic of a sensor is given. The use of compensation algorithms of the cross impact and the linearization of the positional characteristic of sensing element offered to reduce nonlinearity of the sensor positional characteristic to 1% and to reduce the cross impact of different measuring channels to minus 20 dB, which is confirmed by experimental studies. Results of the experimental studies revealed that even without application of special temperature correction methods, the sensors used possess sufficiently high stability. Their phalanx temperature coefficient does not exceed 0,08%/°C. Assessment of high-speed performance of system, taking into account computing opportunities of the electronic transceiver is carried out. Technical characteristics of sensor prototypes and the electronic transceiver of fiber optical system are given. © 2017 The Authors.


Bashkirov E.K.,Samara National Research University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2017

The entanglement between two identical two-level atoms successively passing the thermal cavity has been investigated taking into account the detuning. The case when atoms are initially prepared in the Bell types entangled atomic states has been considered. It has been shown that for vacuum state of the cavity the presence of detuning leads to decreasing of the entanglement amplitude oscillations. We have also derived that for thermal field the increasing of the mean photon number leads to decreasing of the entanglement, but the entanglement increases as the detuning increases. For thermal field and small detuning we have established that the effect of sudden death and birth of entanglement takes place and that for large detuning such effect vanishes. © 2016 SPIE.


Bashkirov E.K.,Samara National Research University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2017

An exact solution of the problem of two two-level atoms with degenerate Raman two-photon transitions interacting with one-mode coherent or thermal radiation field in cavity is presented. Asymptotic solution for system state vector is obtained in the approximation of large initial coherent fields. The atom-field is investigated on the basis of the reduced atomic entropy dynamics. The possibility of the system being initially in a pure disentangled state to revive into this state during the evolution process is shown. Conditions and times of disentanglement are derived. The atom-atom entanglement is investigated with using negativity. The possibility of sudden death and birth of atom-atom entanglement is predicted for a coherent field with large mean photon numbers. © 2016 SPIE.


Makaryants G.M.,Samara National Research University
Journal of Loss Prevention in the Process Industries | Year: 2017

Pressure relief valves (PRVs) in systems supporting constant vessel pressure are required to operate over a wide range of valve strokes, of set pressures and external impacts such as adjacent components vibration, ambient temperature, etc. At the same time, valve operation should be stable, reliable and precise. The aim of this work is to broaden the current knowledge of the PRV self-excited oscillation mechanism. The methods employed during the study are time history review with further spectrogram post processing of the valve input and output parameters in its opening and closing modes. Furthermore, the experimental investigations include valve tests under external vibration conditions. Additionally, an experimental verified mathematical model has been developed that can explain the nature of the valve self-excited oscillation onset. The model represents a one-dimensional approach to predict valve dynamics enhanced with a three-dimensional simulation of the flow choked through the valve. The experimental investigation demonstrated low-frequency self-excited oscillation in the range of 1–10 Hz (amounting to 0.04–0.4 of the valve spring-mass eigenfrequency) throughout the valves, but a number of the valves showed their failure proneness at high-frequency self-excited oscillations within the range of 100–120 Hz (amounting to 4.0 to 4.8 of the valve spring-mass eigenfrequency). The experiments have shown that the reasons of this kind of damage are low-frequency self-excited oscillation as well as external vibration coupled with acoustic resonance of the vessel with an attached the pipe leading to fleeting reduction of drag force in the valve and to high-frequency valve chatter. To prevent of high-frequency self-excited oscillation, the developed design features allow constant and appropriate value of friction force required for chatter elimination in all operating modes of the valve. © 2017 Elsevier Ltd


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.

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