In this paper, the main radiative processes, for the first time, are considered within the framework of continuum physics, where the motion of charged particles occurs in a continuous resisting medium.
Within the analysis, new characteristics of the interaction of ions with matter are introduced. The proposed formalism also uses some results of modern corpuscular theory. It allows giving a physically clear space-time description of the processes and phenomena analyzed in this paper. Further in this paper, the authors have estimated, with a high degree of accuracy, the ranges of ions in various materials; constructed their energy loss profiles; determined the mean free path and mean free time of the charged particles in matter, and proposed the formalism for analyzing the radiative change in the physical properties of solids. For the first time, the physical nature of the main characteristic of the radiation resistance of materials, i.e., the threshold displacement energy, has been studied in detail, and the formula for its calculation has been derived by the authors.

Planar-view TEM investigation revealed the formation of cubic silicon carbide layers on porous silicon by vacuum carbidization. The formation of cubic silicon layers in the form of a two-phase system was found. At the same time, the formed SiC layers on the mesoporous buffer layer are predominantly polycrystalline. Using the Rutherford backscattering method, it was found that the use of buffer layers of porous silicon makes it possible to obtain SiC layers of greater thickness than on a pure silicon substrate under similar conditions of vacuum carbidization. It is shown that an increase in the pore size in porous silicon layers leads to an increase in the thickness of the formed SiC layers. It has been shown by scanning electron microscopy that vacuum carbideization of porous silicon leads to formation of SiC grains in pores, partial overgrowth and sintering of pores. The dependence of the SiC grain size on the pore size was established.

One of the most informative parameters of the signal of radar signals is its carrier frequency. Measuring and memorizing the carrier frequency of a reconnaissance radio-electronic device is one of the most important functions of a radio intelligence station, radio monitoring. Using the concept of an analytical signal, any signal can be represented through an envelope and phase, or quadrature components, which makes it possible to calculate the instantaneous frequency. The purpose of the work is to determine the effectiveness of the instantaneous frequency calculation method based on direct conversion in the time domain using several differentiators for measuring the time and frequency parameters of a chirp signal. The developed algorithm makes it possible to measure such parameters of the signal with chirp as steepness, pulse duration, repetition period, central frequency, spectrum width. This paper presents the implementation of an algorithm for measuring the instantaneous frequency with augmented double differentiation. The first differentiation allows you to measure the steepness of the signal as a sample average, the second differentiation – time points (pulse duration, repetition period). The signs of signal portraits are presented for a symmetrical, asymmetric signal with chirp, as well as in the absence of intra-pulse modulation. The simulation results showed that with the ratio of the sampling frequency to the signal band equal to 2.3, the error in measuring the steepness of the signal is 25 %, and at 11 – 8.8 %; the simulation results were carried out with a signal-to-noise ratio of 10 dB.

The article considers the approach developed by the authors to adapt the detection algorithm based on the background subtraction method to work in a scanning optoelectronic surveillance system. This algorithm is the basis of the developed image processing method applied to the problem of detecting moving objects by an optoelectronic thermal imaging surveillance system. At the same time, this method provides a solution to the tasks of protecting a critical object with an optoelectronic surveillance system, which must function both in stationary and scanning mode. The use of an improved mixture of Gaussian distributions to build a background model makes it possible to adapt to periodic changes in pixel brightness from dynamic background elements of the observed scene. However, the application of this detection algorithm in a scanning optoelectronic system requires the solution of the following problematic issues: the exclusion of false highlighting of the areas of the processed image in the foreground when transferring the sensor field of view; the elimination of errors in the initial values of the parameters of a mixture of Gaussian distributions. The application of the approach proposed by the authors to solving these issues is implemented in a specialized optoelectronic surveillance system and allows achieving the same quality of the detector based on the background subtraction method in scanning mode as in stationary mode.

 Currently, fiber-optic communication lines are widely used for data transmission. Despite the fact that the information signal propagates inside the optical fiber, covered with a protective shell, there are various ways to form information leakage channels from such fibers. The power control of the information signals transmitted over an optical fiber is one of the most common ways to detect an information leakage channel. This paper determines the parameters of a fiber-optic communication line based on multimode optical fibers for which silicon photomultipliers to detect information leakage channels can be used. The dependences of the branched power on the fiber bending diameter are presented. It has been found that the bending diameter increase leads to the branched power decrease and a decrease in the ability of the photodetector to detect power loss in the optical fiber. The value of the branched power of optical radiation with a wavelength of 850 nm is greater than for 650 nm for all studied bending diameters. It has been established that an increase in the optical radiation power introduced into the fiber to 10 mW makes it possible to detect power loss up to –0.005 dB for an optical radiation wavelength of 850 nm, and –0.142 dB for a wavelength of 650 nm. The results of this article can be used in systems for protecting information transmitted over fiber-optic communication lines.

A method of information leakage channel security estimating based on the test speech signal envelope cross-correlation analysis is proposed and its includes: test signal generating and extracting its envelope, emitting and measuring in a leakage channel, extracting the resulting signal envelope, calculating the correlation coefficient between the original and received envelopes, and comparing with a threshold value. A metod for extracting a low-frequency signal envelope using the Hilbert transform is shown. A description of the cross-correlation analysis based on the Pearson correlation coefficient is given. The leakage channel simulation modeling, formation and measurement of the test signals was performed in the MatLab. The obtained results confirm the greater efficiency of using the envelope compared to the original signal, and demonstrate the speech signals advantage over harmonic signals as test signals for assessing the information leakage channel security.

The problem of constructing characteristics of the difference between test sequences is investigated. Its relevance for generating controlled random tests and the complexity of finding difference measures for symbolic tests are substantiated. The limitations of using the Hamming and Damerau–Levenshtein distances to obtain a measure of the difference between test patterns are shown. For an arbitrary case, a new measure of the difference between two symbolic test sets is determined based on the interval used in the theory of the chain of successive events. The distance D(Ti, Tk) between test patterns Ti and Tk, using the interval characteristic, is based on determining independent pairs of identical (equal) symbols belonging to two patterns and calculating the intervals between them. The combinatorial nature of the calculation, the proposed difference measure for symbolic test patterns of an arbitrary alphabet and dimension, is shown. An example of calculating this measure is given and its possible modifications and limitations are shown. The application of the measure of difference is considered for the case of multi-run testing of memory devices based on address sequences pA with even p repetition of addresses. For the case p = 2, mathematical relations are given for calculating intervals and distances D(Ti, Tk) for address sequences 2A used for controlled random testing of memory devices. Experimental results are presented confirming the effectiveness of the proposed difference measure.

The results of evaluating the efficiency of algorithms for segmentation of images of surfaces of materials with an absent or weakly expressed substrate and a convex shape of objects obtained using an atomic force microscope (AFM images), as well as synthesized in the Matlab and Gwyddion software are presented. For segmentation, algorithms were used based on wave growth of local maximum regions with their selection in decreasing order of values (without stopping and with stopping at a given level), marker watershed (with automatic placement of markers, under the control of the operator), watershed based on distances, growing areas (without selecting starting points, with the choice of starting points based on extrema), the Vincent – Sulli watershed (classical, with a preliminary calculation of the gradient in an eight-connected area, with the selection of the contours of the areas and their subsequent filling), a two-phase watershed. Segmentation algorithms realization in Matlab and in the specialized software package Gwyddion are considered. Algorithms efficiency was assessed using segments number, uniformity brightness within a segment, contrast at the border of adjacent segments, and a complex criterion that takes into account the uniformity of segments brightness, their number and size.

To study tissue permeability under extracorporeal exposure to various types of radiation, it is necessary to use multiphysical and mathematical modeling of all stages of the technology being developed, taking into account the dielectric and acoustic properties of human body tissues. The technologies used in medicine with focused ultrasound often have a high level of artifacts in the visualization of diagnostic studies and complications during therapy. When modeling exposure to focused ultrasound, the applied solvers must take into account pressure wave propagation, density changes and jumps, non-linearity and diffusion losses that occur in human tissues, and offer simulation of acoustic propagation in inhomogeneous installations in near real time. The article presents the results of multiphysics and mathematical modeling in the Sim4Life for Science V7.0 package using a full-wave acoustic solver (P-ACOUSTICS) of modern computational acoustics.

The purpose of the article is to present the process of modeling the IoT smart home (SH) network, which combines both user needs and efficiency requirements. The use of Alibaba cloud platform, which reduces complexity and development time, reduces costs, was justified in the project of building the IoT SH network. The structure of this platform is given, its main components are considered and an algorithm for its configuration is given. MQTT is used as an access protocol in the IoT SH network to achieve fast and reliable data transmission. Open source code, reliability, simplicity and other characteristics justify the choice of this data transfer protocol. Modeling of the network IoT SH is based on the knowledge gained in the process of practical implementation. First, the online problems of the system are tested, after the system is able to work after modification and debugging of programs, a street lamp is used as an example to create an instance of an IoT SH network on a cloud platform. The process of creating an example of an IoT SH network is described in detail in steps, in which data from a street lamp is transmitted to a cloud platform, processed there, and then displayed on a mobile device. A mobile phone was used to implement two-way interaction, simulate the sensor of the IoT SH network and display the results. The algorithms for configuring the platform, modeling the sensor and creating an object model of the device of the IoT SH network are given. For some modern control systems, this system is compatible and suitable for a larger number of cases, which contributes to the development of intelligent control in the IoT network.

The article proposes improvements to the method for determining the fire hazard level in forests based on predictive meteorological and aerospace data. A brief analysis of various methods for the fire hazard level determining in forests and the sets of initial parameters used in this case was carried out in order to determine the final method's optimal characteristics and properties for further application. The calculation of the fire hazard assessment is based on the flammability basic indicator according to weather conditions and correction factors based on the vegetation indices values. Vegetation indices division into quartiles is proposed for a vegetation relative assessment in the territory under consideration. Maps of the forest blocks distribution by fire hazard classes for the Volozhinsky forestry enterprise territory were obtained according to the proposed and other methods. A comparative analysis of the numerical and spatial characteristics of the obtained assessments of forests fire hazard using various methods was carried out. According to the improved methodology assessment results, its application results correlate with the assessment according to the standardized methodology, but adjusted according to the vegetation assessment results. It is advisable to verify the proposed methodology during a fire hazard period in real conditions, followed by an assessment of the results and refinement if necessary.

The paper considers the results of a study of the influence of the relative position of moisture-containing pseudooval scattering elements with linear dimensions of 10…20, 2…4, 1…4 and 1…2 mm on the electromagnetic radiation reflection coefficients values of the electromagnetic radiation shielding structures, including these elements, and the effective scattering surface of the ground objects, on the surface of which the indicated structures are fixed or applied. Placement of three- or two-layer structures formed on the basis of pseudooval elements with linear dimensions of 2...4, 1...4, 1...2 mm, between two monolayers made on the basis of elements with dimensions of 10...20 mm, leads to the decrease up to –17,6 dB of the electromagnetic radiation reflection coefficients values in the frequency range of 2–12 GHz of the electromagnetic radiation shielding structures, including these elements. The values of the effective scattering surface of ground objects, on the surface of which the indicated electromagnetic radiation shielding structures are located, vary within 0,08...11,80 m2, which is the reason of a significant difficulty in intercepting information about the location and characteristics of ground objects by means of technical intelligence in the frequency range of their operation.