Statistical characteristics of the current flowing through semiconductor superlattice, with structure fluctuations
Statistical characteristics of the current flowing through semiconductor superlattice, with structure fluctuations
A. О. Selskii, O. I. Moskalenko, A. A. Koronovskii
The paper investigates how fluctuations in the lattice structure, namely the width of the conducting miniband, affect the current flowing through a semiconductor superlattice. To solve this problem, a numerical calculation model is proposed that makes it possible to calculate the current for random changes in the miniband width in the superlattice layers, both in the case of an inclined magnetic field and without it. In order to evaluate the change in current, two integral characteristics were introduced: one for the shape of the current-voltage characteristic, the second for the amplitude of high-frequency current oscillations. The integral characteristics ranked in ascending order make it possible to approximately approximate the variability of the characteristics of the current flowing through a semiconductor superlattice for various fluctuations of the lattice structure.
Show AbstractStatistical analysis of the characteristics of recurrent analysis of various stages of sleep
Statistical analysis of the characteristics of recurrent analysis of various stages of sleep
A. О. Selskii$^{1,2}$, M. О. Zhuravlev$^{1,2}$, M. Yu. Novikov$^1$, A. E. Runnova$^1$
This article discusses the statistical analysis of recurrent indicators calculated for different stages of sleep in three groups of subjects: healthy people, with Parkinson's disease, and with sleep apnea. Statistical analysis included the calculation of recurrent indicators and parameters associated with the estimation of the spread of recurrent indicators for sleep stages compared with the average value for this stage and for the entire night recording. It has been shown that for patients with Parkinson's disease, the spread of the recurrent indicator for the wakefulness stage is extremely large, which makes further analysis difficult, but can be a good biomarker for early recognition of the disease. For apparently healthy subjects and patients with sleep apnea, sleep stages 3 and 4 differ most from the overnight averages, but have the smallest deviations from the average for this stage. Patients with sleep apnea have a higher dispersion for REM sleep compared to healthy subjects.
Show AbstractAlgorithm for determining the optical profile of thin gradient-index films via surface plasmon resonance
Algorithm for determining the optical profile of thin gradient-index films via surface plasmon resonance
A. V. Anisimov, S. A. Lobastov, I. S. Khasanov
This work details the physical and mathematical foundations of an algorithm to determine the optical profile of thin gradient films using the surface plasmon resonance (SPR) method. The algorithm minimizes the discrepancy function, which quantifies the deviation between experimental data and model data of the targeted gradient layer, approximated using a cubic Hermite interpolant known as PCHIP. Powell's method optimization, implemented in Python, determines the optimal coordinates for the spline nodes approximating the gradient optical layer. To enhance stability, accuracy, and search speed, the algorithm operates in three stages. Each stage refines the search area and sets initial parameters for the subsequent stage to align closely with the targeted gradient layer. The algorithm incorporates angle, wavelength, and external environment scan data derived via SPR.
Show AbstractCorrection of recurrent analysis taking into account the frequency of the EEG signal on the example of processing cognitive tests of patients with migraine
Correction of recurrent analysis taking into account the frequency of the EEG signal on the example of processing cognitive tests of patients with migraine
E. P. Emelyanova$^1$, A. О. Selskii$^{1,2}$, A. E. Runnova$^{1,2}$
Recurrent analysis is a good correlation method of processing EEG data of the human brain. It is aimed at identifying links between channels. In particular, the modified recurrent analysis is designed to identify the most significant channels with a certain activity. At the same time, recurrent analysis is a method that strongly depends on frequency. The paper proposes a method for correcting the results obtained by recurrent analysis of the EEG processing of the brain data of the subjects, taking into account the frequency based on the Fourier transform.
Show AbstractMethods and Experimental installations Lomonosov Moscow State University - Skobeltsyn Institute of Nuclear Physics for determining the impact strength of polymer nanocomposites
Methods and Experimental installations Lomonosov Moscow State University - Skobeltsyn Institute of Nuclear Physics for determining the impact strength of polymer nanocomposites
V. A. Kobzev$^{1,2}$, N. G. Chechenin$^{1,2}$, S. S. Avtorin$^{1,2}$, N. B. Akimov$^1$, S. A. Bednyakov$^1$, A. V. Makunin$^1$
Experimental equipment for determining the impact resistance of composite materials by the method of impact pendulum copra and low-speed ballistic method is described. Two types of polymer nanocomposites have been studied: consisting entirely of epoxy resin reinforced with carbon nanotubes and layered composites of fiberglass and basalt fabric impregnated with epoxy resin reinforced with carbon nanotubes. Measurement methods are proposed.
Show AbstractOptimizing big data distributed processing: Algebraic foundations and the concept of information
Optimizing big data distributed processing: Algebraic foundations and the concept of information
P. V. Golubtsov
An algebraic formalization of distributed processing of big data is considered. The concept of information space is defined for a given data processing procedure and a criterion for its minimality is established. The existence of a minimal information space is proved, which provides the most compact form of representation of the information contained in the data and allows the most efficient parallelization of data processing. An element of this space describes in a consistent way the information contained in the corresponding data set. It is shown that in terms of the information space, the concepts of information addition and information quality are naturally expressed, reflecting the intuitive idea of the very concept of information. The advantages of using the minimal information space in the MapReduce distributed data processing model are also considered. In the context of this model, Map transforms the original data sets into information space elements, and Reduce combines all these pieces of partial information into a single element representing all the original data. By way of illustration, several examples of data processing procedures are analyzed and the corresponding minimal information spaces are presented.
Show AbstractMultilevel research works of schoolchildren on the celestial mechanics problems implementation
Multilevel research works of schoolchildren on the celestial mechanics problems implementation
S. B. Ryzhikov$^1$, Yu. V. Ryzhikova$^2$
The problem of involving schoolchildren in research activities is considered. The reason for the low schoolchildren motivation is indicated - the first research work results appear only after a few weeks. A methodology for conducting multi-level work is proposed, in which the results are obtained already at the first lesson. An example of such multilevel research work based on the celestial mechanics problems is considered.
Show AbstractHeat capacity of neon, argon, krypton and xenon crystals at high temperatures
Heat capacity of neon, argon, krypton and xenon crystals at high temperatures
P. N. Nikolaev
The heat capacity of rare gas crystals is studied in the paper. For this, the cell-cluster expansion for the free energy is used, taking into account three-particle clusters, inclusive. The self-consistent field approximation is used as the basic approximation. The calculations performed for neon, argon, krypton and xenon showed good agreement between the theoretical results and experimental data. This also applies to regions at normal pressure for krypton and xenon, where the heat capacity at constant volume decreases with increasing temperature.
Show AbstractOn the set of solutions to the Schrodinger equation on the example of the description of water clusters
On the set of solutions to the Schrodinger equation on the example of the description of water clusters
K. E. Plokhotnikov
The article discusses a computational procedure for obtaining all possible solutions to the Schrodinger equation by statistical testing or the Monte Carlo method. Clusters of water, namely hexamer, dodecahedra, and tetradecamer, act as a demonstration quantum system illustrating this procedure. Various solutions of the Schrodinger equation are derived from the computational algorithm proposed by the author earlier, based on the intersection of finite-difference, Monte Carlo approaches, the virial theorem, as well as methods tested on water clusters for spatial information of the scattering centers of particle nuclei and electron scattering centers of an arbitrary quantum system. A variety of information schemes are considered, among them are specially highlighted: single-particle, two-, three-, etc. up to the scheme with maximum partiality. Within the framework of any of the information schemes, the dissociation energy of the quantum system under consideration is consistent, on the one hand, and the positioning of the scattering centers of particle nuclei and electrons, on the other hand. The method of solving the Schrodinger equation proposed earlier by the author by the Monte Carlo method acts as a means of selecting configurations acceptable as solutions. As a result, it turned out to be possible to construct an algorithm for generating an unlimited number of different spatial structures of scattering clouds of particle nuclei and electrons at a given dissociation energy of a quantum system. The computational procedure proposed in this paper allows for a natural generalization for the case of describing an arbitrary quantum system whose elemental composition is known. The procedure is computationally efficient, because it allows parallelization of calculations.
Show AbstractImpact of tensor interaction on the structure of silicon isotopes
Impact of tensor interaction on the structure of silicon isotopes
S. V. Sidorov$^{1,2}$, T. Yu. Tretyakova$^{1,2}$
The influence of the tensor interaction of nucleons on the characteristics of neutron-rich silicon isotopes was studied in this work. Tensor forces are taken into account within the framework of the Hartree-Fock approach with the Skyrme interaction. It is shown that the addition of tensor component of interaction improves the description of the splitting between different single-particle states and leads to a decrease in nucleon-nucleon pairing correlations in silicon nuclei.
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