Self-dual SU(2) invariant Einstein metrics and modular dependence of theta-functions

We simplify Hitchin's description of SU(2)-invariant self-dual Einstein metrics, making use of the tau-function of related four-pole Schlesinger system.Comment: A wrong sign in the formula for W_1 is corrected; we thank Owen Dearricott who pointed out this mistake in the original version of the pape

Two-band superconductors: Extended Ginzburg-Landau formalism by a systematic expansion in small deviation from the critical temperature

We derive the extended Ginzburg-Landau (GL) formalism for a clean s-wave two-band superconductor by employing a systematic expansion of the free-energy functional and the corresponding matrix gap equation in powers of the small deviation from the critical temperature tau = 1-T/T_c. The two lowest orders of this expansion produce the equation for T_c and the GL theory. It is shown that in agreement with previous studies, the two-band GL theory maps onto the single-band GL model and thus fails to describe the difference in the spatial profiles of the two band condensates. We prove that except for some very special cases, this difference appears already in the leading correction to the GL theory, which constitutes the extended GL formalism. We derive linear differential equations that determine the leading corrections to the band order parameters and magnetic field, discuss the validity of these equations, and consider examples of an important interplay between the band condensates. Finally, we present numerical results for the thermodynamic critical magnetic field and temperature-dependent band gaps (at zero field), which are in a very good agreement with those obtained from the full BCS approach in a wide temperature range. To this end, we emphasize the advantages of our extended GL theory in comparison with the often used two-component GL-like model based on an unreconstructed two-band generalization of the Gor'kov derivation

Mobile Hardware-Information System for Neuro-Electrostimulation

The article describes organizational principles of the mobile hardware-informational system based on the multifactorial neuro-electrostimulation device. The system is implemented with two blocks: the first block forms the spatially distributed field of low-frequency monopolar current pulses between two multielement electrodes in the neck region. Functions of the second block, specialized control interface, are performed by a smartphone. Information is exchanged between two blocks through a telemetric channel. The mobile hardware-informational system allows to remotely change the structure of the current pulses field, to control its biotropic characteristics and to change the targets of the stimulation. Moreover, it provides patient data collection and processing, as well as access to the specialized databases. The basic circuit solutions for the neuro-electrostimulation device, implemented by means of microcontroller and elements of high-level hardware integration, are described. The prospects of artificial intelligence and machine learning application for treatment process management are discussed. © 2018 Vladimir S. Kublanov et al.)is study was supported by the Act 211 of the Government of the Russian Federation (contract no. 02.A03.21.0006) and was funded by RFBR (project no, 18-29-02052)

Regularities of Changes in Structure and Texture of Low Modulus Alloy Zr-25Nb at Cold Rolling of Monocrystals with Different Orientations

The paper presents the results of studying the regularities of formation of the rolling texture in single crystals of Zr-25%Nb alloy, with different initial orientation relative to the external principal directions in the sheet: normal (ND) and rolling direction (RD). Varying the initial orientation of the single crystal made it possible to reveal stable orientations, among which are textural components {001} <100>, {001} <110>, {111} <110> and {111} <112>. For orientation <111> of single crystal, in the matrix of a quasi-single crystal it was possible to detect a finely dispersed ω-phase, which causes the appearance of an extended halo in the diffraction spectrum. The presence o

Principles of organization and control of the new implementation of the “SYMPATHOCOR-01” neuro-electrostimulation device

The paper describes peculiarities of the organizational and control principles of the new implementation of the “SYMPATHOCOR-01” device. Necessity of the device division into two blocks, having different functions, was justified. The specifics of the schematic implementation were mentioned. Advantages of the wireless connection between two blocks were shown. Particular possibilities and actual implementation of the control block via Android application for mobile devices were presented. The potential targets for the neuro-electrostimulation that affect autonomic processes were considered. Copyright © 2017 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved

On some possibilities of organizing a mobile hardware-information system for polyfactorial neuro-electrostimulation

In paper the organizational principles of the mobile hardware-information system for polyfactorial neuroelectrostimulation were considered. It was shown that the system can be implemented by three functionally separate blocks, one of which ensures the formation of a spatially distributed field of current pulses, the second is the specialized interface for the patient, and the third is the specialized interface for the doctor. The exchange of information between the blocks is provided by a telemetric communication channel or via the global network using mobile wearable computers (which can include a personal computer, tablet or smartphone). A personalized patient information system can be implemented on the basis of the neuroelectrostimulation system. In this case patient data can be placed on the server of the medical institution. The prospects for using artificial intelligence and machine learning to control the treatment process were discussed. © 2019 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved

Regular modes in rotating stars

Despite more and more observational data, stellar acoustic oscillation modes are not well understood as soon as rotation cannot be treated perturbatively. In a way similar to semiclassical theory in quantum physics, we use acoustic ray dynamics to build an asymptotic theory for the subset of regular modes which are the easiest to observe and identify. Comparisons with 2D numerical simulations of oscillations in polytropic stars show that both the frequency and amplitude distributions of these modes can accurately be described by an asymptotic theory for almost all rotation rates. The spectra are mainly characterized by two quantum numbers; their extraction from observed spectra should enable one to obtain information about stellar interiors.Comment: 5 pages, 4 figures, discussion adde

Simulación del sistema de estabilización de altitud de vuelo en quadcopter

Recently, unmanned aerial vehicles have been an important part of scientific research in various fields. Quadrocopter is an unmanned aerial vehicle with four rotors, two of which rotate clockwise, the other two counterclockwise. Changing the speed of screw rotation allows you to control the movement of the apparatus. The article proposed and tested a mathematical model of a quadcopter. They presented the development of a simple control algorithm that allows to stabilize the height and angular position. The research results show the efficiency of the algorithm and the possibility of its practical implementation. The developed mathematical model can be used instead of a real quadcopter, which will significantly reduce the time during research, as well as avoid the quadrocopter damage, reducing the number of launches.Recientemente, los vehículos aéreos no tripulados han sido una parte importante de la investigación científica en varios campos. Quadrocopter es un vehículo aéreo no tripulado con cuatro rotores, dos de los cuales giran en sentido horario y los otros dos en sentido antihorario. Cambiar la velocidad de rotación del tornillo le permite controlar el movimiento del aparato. El artículo propuso y probó un modelo matemático de un quadcopter. Presentaron el desarrollo de un algoritmo de control simple que permite estabilizar la altura y la posición angular. Los resultados de la investigación muestran la eficiencia del algoritmo y la posibilidad de su implementación práctica. El modelo matemático desarrollado se puede utilizar en lugar de un cuadricóptero real, lo que reducirá significativamente el tiempo durante la investigación, además de evitar el daño del cuadricóptero, reduciendo el número de lanzamientos