Localization of quantum biequivariant Ɗ-modules and q–W algebras

The author is grateful to Y. Kremnizer for useful discussions and to the referee for careful reading of the manuscript.Peer reviewedPostprin

Investigation of cosmic ray propagation in interplanetary space

It was established experimentally that propagation of solar cosmic rays (scr) in interplanetary space up to 1 AU in most cases was of diffusion character

Компьютерная система обнаружения COVID-19 по рентгеновским снимкам легких методами глубокого обучения

Early detection of COVID-19 infected patients is essential to ensure adequate treatment and reduce the load on the healthcare systems. One of effective methods for detecting COVID-19 is deep learning models of chest X-ray images. They can detect the changes caused by COVID-19 even in asymptomatic patients, so they have great potential as auxiliary systems for diagnostics or screening tools. This paper proposed a methodology consisting of the stage of pre-processing of X-ray images, augmentation and classification using deep convolutional neural networksXception, InceptionResNetV2, MobileNetV2, DenseNet121, ResNet50 and VGG16, previously trained on theImageNet dataset. Next, they fine-tuned and trained on prepared data set of chest X-rays images. The results of computer experiments showed that theVGG16 model with fine tuning of the parameters demonstrated the best performance in the classification of COVID-19 with accuracy 99,09%, recall=98,318%, precision=99,08% and f1_score=98,78. This signifies the performance of proposed fine-tuned deep learning models for COVID-19 detection on chest X-ray images

Statistical Channel Model for 60 GHz WLAN Systems in Conference Room Environment

In this work, a methodology of statistical channel modeling for 60 GHz WLAN systems is proposed and a channel model for the office conference room environment is developed. The proposed methodology takes into account the most important properties of the indoor 60 GHz propagation channel such as large propagation loss and necessity to use steerable directional antennas by the WLAN stations, quasi-optical propagation nature, clustering structure of the channel, and significant impact of the polarization characteristics. A general mathematical structure of the channel model that supports all the described 60 GHz propagation channel properties is suggested. Then the conference room scenario for 60 GHz WLAN systems is introduced. Development of the inter cluster, intra cluster, and polarization impact modeling parameters is considered in details first explaining the used methodology for each channel modeling aspect and then followed by its application to the conference room scenario. The raw data for the channel model development include the experimental results [1], [2] and ray-tracing simulations for the conference room scenario. The proposed channel modeling methodology and the developed conference room channel model were adopted by the IEEE 802.11ad committee for 60 GHz WLAN systems standardization

Effect of long-term operation on energy band bending at the SnO2 microcrystals interfaces in thin tin dioxide films with various catalysts

This work presents the results of investigation of stability of energy band bending at the SnO2 microcrystals interfaces in thin films of tin dioxide with deposited Pt and Pd dispersed layers (Pt/Pd/SnO2:Sb) and with the additions of gold in the bulk and on the surface (Au/SnO2:Sb, Au) in long - term operation. Measurements of energy band bending were showed that the significantly variation of this value is observed in first month of the sensor using. Perhaps this phenomenon is caused by the surface reconstruction during operation of sensors and consequently by the increase of density of oxygen ions chemisorbed on the surface of tin dioxide

Operator Approach to the Master Equation for the One-Step Process

Presentation of the probability as an intrinsic property of the nature leads researchers to switch from deterministic to stochastic description of the phenomena. The procedure of stochastization of one-step process was formulated. It allows to write down the master equation based on the type of of the kinetic equations and assumptions about the nature of the process. The kinetics of the interaction has recently attracted attention because it often occurs in the physical, chemical, technical, biological, environmental, economic, and sociological systems. However, there are no general methods for the direct study of this equation. Leaving in the expansion terms up to the second order we can get the Fokker-Planck equation, and thus the Langevin equation. It should be clearly understood that these equations are approximate recording of the master equation. However, this does not eliminate the need for the study of the master equation. Moreover, the power series produced during the master equation decomposition may be divergent (for example, in spatial models). This makes it impossible to apply the classical perturbation theory. It is proposed to use quantum field perturbation theory for the statistical systems (the so-called Doi method). This work is a methodological material that describes the principles of master equation solution based on quantum field perturbation theory methods. The characteristic property of the work is that it is intelligible for non-specialists in quantum field theory. As an example the Verhulst model is used because of its simplicity and clarity (the first order equation is independent of the spatial variables, however, contains non-linearity). We show the full equivalence of the operator and combinatorial methods of obtaining and study of the one-step process master equation.Comment: in Russian; in Englis

Characteristic of the snow cover for the Western Siberia territory

The warming for the Siberian territory has more rapid growth, than for Northern Hemisphere, in general. The purpose of the work is the description of characteristics of a snow cover for the south-east territory of the Western Siberia, which is great importance for many branches of the economy of Siberia. Date of appearance of snow cover, duration of a steady snow cover, thickness were analyzed in present research. The presented results are: the increase in duration of the presence the snow cover is revealed. The reason is the increase in amount of precipitation during the winter period