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The article’s aim is to create a method of reducing the influence on the surface eddy current probes output signal of a number of interfering parameters without their elimination, to ensure its stability, which is achieved as a result of computer search of design and operating values of probes Taguchi-parameters at the stage of their design. To achieve the goal the following tasks were carried out: software for calculating the output signal of surface probes, which is based on the electrodynamic model of the measurement process for the test object in the form of a con-ductive plate of infinite overall dimensions and finite thickness; using the Taguchi method, a special design of experiments with the use of orthogonal arrays is constructed, the fulfillment of which makes it possible to determine the influence of each parameter and their complex nonlin-ear interaction on the output signal of the probe; by integrating the Taguchi method with com-puter numerical simulation, the optimal controllable parameters of the probe were determined, minimizing the signal changes caused by noise factors. The most important research result is the method creation of providing the signals probes stability and reducing the influence of noise pa-rameters on them simultaneously without their elimination. The method effectiveness is demon-strated on the example of designing a thickness gauge, which allowed computer search for a set of its optimal parameters to maximize the signal-to-noise ratio, thereby reducing the signal varia-bility. The significance of the obtained results lies in the creation of theoretical and practical ap-proaches to the design of surface eddy current probes with new properties of interfering factors suppression, which provide the best conditions for reliable diagnostics of power equipment ob-jects.

Based on the proposed methodology, the essence of which is to identify the profiles of electrophysical parameters of planar objects of eddy-current testing by means of surrogate optimization in the active PCA-space of reduced dimensionality, the effectiveness of the approach is proved by modeling the process of measurement control using apriori accumulated information about an object, in particular, multifrequency probing. The particularity of these studies is the consideration of previously collected information not only on profile variations, but also on the effect of various object probing frequencies on the signal of the surface probe. The functions of the storage device and information carrier were performed by a neural network metamodel, characterized by a high computational efficiency. Numerical experiments have determined the accuracy indicators of the proposed improved method for determining the distributions of magnetic permeability and electrical conductivity along the subsurface layer of a metal object with changes in a microstructure. The analysis of the modeling results indicates a significant reduction in the level of computational resources required to solve the problem and an increase in the accuracy of profile identification.

The article presents results of a study of the chemical composition of garnet xenocrystals from a concentrate of the heavy fraction of kimberlites from the Yubileinaya pipe and Ottorzhenets kimberlite body. Samples from porphyry kimberlites and autolithic kimberlite breccias were taken for analysis from the Yubileinaya pipe. Significant differences are noted in the studied samples of peridotite garnets from the Yubileinaya kimberlite pipe and the Ottorzhenets body. Compared to the Yubileinaya pipe, the Ottorzhenets body exhibits a decreased amount of garnets of the harzburgite-dunite paragenesis in the composition range of Cr2O3 > 8.5 wt. % and CaO < 3 wt. %. On this basis, we assume that the Ottorzhenets body is not a displaced fragment of the Yubileinaya pipe, but belongs to a new unknown kimberlite body. We also assume that the diamond-bearing potential of the primary Ottorzhenets body is reduced compared to the Yubileinaya pipe, which is consistent with the information on the diamond content, according to the data of ALROSA (PJSC).

New methods for identifying the material properties of planar objects as a result of measurements by the eddy current method are proposed. The methods are based on the latest surrogate strategies and advanced optimization techniques that improve efficiency and reduce resource consumption of problem solutions, and balance computational complexity with the accuracy of the results. High-performance metamodels for global surrogate optimization are based on deep truly meaningful fully connected neural networks, serving as an additional function of accumulating apriori information about objects. High accuracy of the approximation of the multidimensional response surface, which is determined by the “exact” electrodynamic model of the testing process, is ensured by performing calculations according to the computer design of a homogeneous experiment with a low weighted symmetric centered discrepancy. The results of numerical experiments performed for full and reduced dimensional search spaces, which can be obtained by linear transformations using the principal component method, are presented. The verification of the methods proved their sufficiently high accuracy and computational performance.

Background. An analysis of existing methods for automatically searching for correspondence in stereo images has shown that there are problematic issues in the field of automating the search for correspondence in stereo pairs from the point of view of simultaneously minimizing computational costs and ensuring the accuracy of calculations. They are associated, first of all, with the automatic determination of the position of the search area, limited on both sides and adaptive in shape and nature of distortion, under the conditions of ensuring the possibility of its restructuring in real time with dynamic changes in the relative position in the space of video channels with known and unknown internal parameters, and also when processing high-resolution images without their preliminary pixel-by-pixel processing. Materials and methods. The problem to be solved by the proposed methods for automatically determining the position of the search area for correspondence was to construct a search area for an object in a stereo image that is limited on both sides and adaptive in shape by the nature of the distortion, provided that it is possible to quickly rearrange it in cases of dynamic changes in the relative position in the space of digital images. video channels with known and unknown internal parameters. As a result, two methods were developed for automatically determining the boundaries and position of the adaptive search area, based on calculating the values of arrays containing the pixel coordinates of the object search area in a stereo image. The adaptive property of the search area in this case consisted in the automatic change of its shape and size in accordance with the geometric distortions of the images and the current relative position of the video channels. Results. Increased performance compared to existing methods for determining areas of local search for correspondence is achieved due to the absence of the need for preliminary pixel-by-pixel image processing, calculation of the fundamental matrix and solving complex systems of equations. Conclusions. As a result, the requirements for computer computing resources have been reduced and the real-time automatic search for matches in distorted images from high-resolution video channels dynamically changing their spatial position and orientation has been achieved. In addition, the implementation of a technical vision system is simplified due to the possibility of using video channels with unknown technical parameters.

In order to establish the projection properties of computer uniform designs of experiments on Sobol’s sequences, an empirical comparative statistical analysis of the homogeneity of 2D projections of the best known improved designs of experiments was carried out using the novel objective indicators of discrepancies. These designs show an incomplete solution to the problem of clustering points in low-dimensional projections graphically and numerically, which requires further research for new Sobol’s sequences without the drawback mentioned above. In the article, using the example of the first 20 improved Sobol’s sequences, a methodology for creating refined designs is proposed, which is based on the unconventional use of these already found sequences. It involves the creation of the next dimensional design based on the best homogeneity and projection properties of the previous one. The selection of sequences for creating an initial design is based on the analysis of numerical indicators of the weighted symmetrized centered discrepancy for two-dimensional projections. According to the algorithm, the combination of sequences is fixed for the found variant and a complete search of the added one-dimensional sequences is performed until the best one is detected. According to the proposed methodology, as an example, a search for more perfect variants of designs for factor spaces from two to nine dimensions was carried out. New combinations of Sobol’s sequences with better projection properties than those already known are given. Their effectiveness is confirmed by statistical calculations and graphically demonstrated box plots and histograms of the projection indicators distribution of the weighted symmetrized centred discrepancy. In addition, the numerical results of calculating the volumetric indicators of discrepancies for the created designs with different number of points are given.

Soils of boreal forests are crucial carbon reserves. The response of soil carbon emission to climate change significantly affects the concentration of carbon dioxide in the atmosphere. Soil carbon emission models frequently show a nonlinear response to temperature, but soil moisture is an important limiting factor, often overlooked in energy limited ecosystems. We suggest a statistical model of soil CO2 emission constrained by soil moisture and temperature for different ecosystems in the boreal zone. We tested this modelling strategy using direct measurements of seasonal soil CO2 emission near the research observatory ZOTTO near the Bor settlement, Central Siberia, Russia, in 2012-2017. Soil moisture explained a significant amount of variability of soil emission: the adjusted R2 was twice higher than in the baseline model. Although the temperature-only model describes the annual variability of carbon dioxide emissions quite well, the addition of moisture measurement significantly refines the quality of prediction of the seasonal component dynamics. Models including both temperature and soil moisture could serve as a promising tool to analyze the carbon cycle in boreal forest ecosystems.

Background. The aim of the work is to create a prototype of software for hardware control of a new multiaxis platform for virtual reality with simulated environmental effects and feedback, providing a complete immersion of the user in virtual reality through exposure to sensory biological signaling systems (tactile, vestibular, auditory, visual). Materials and methods. As part of the implementation of this project, a software product has been created to control a multiaxis platform for virtual reality, providing full immersion of the user with simulated environmental impact and feedback. Results. The result of the project is a working prototype of the system.

Based on the proposed methodology, the essence of which is to identify the profiles of electrophysical parameters of planar objects of eddy-current testing by means of surrogate optimization in the active PCA-space of reduced dimensionality, the effectiveness of the approach is proved by modeling the process of measurement control using apriori accumulated information about an object, in particular, multifrequency probing. The particularity of these studies is the consideration of previously collected information not only on profile variations, but also on the effect of various object probing frequencies on the signal of the surface probe. The functions of the storage device and information carrier were performed by a neural network metamodel, characterized by a high computational efficiency. Numerical experiments have determined the accuracy indicators of the proposed improved method for determining the distributions of magnetic permeability and electrical conductivity along the subsurface layer of a metal object with changes in a microstructure. The analysis of the modeling results indicates a significant reduction in the level of computational resources required to solve the problem and an increase in the accuracy of profile identification. [ABSTRACT FROM AUTHOR]

Existing scientific studies devoted to the design of eddy-current probes with a priori given configuration of the electromagnetic excitation field, which provide a uniform eddy current density distribution, consider a wide class of such, but are limited to the case when the probe is stationary relative to the testing object. Therefore, the actual problem is the synthesis of moving tangential eddy current probes with a frame excitation system that provides a uniform eddy current density distribution in the testing object, the solution of which is proposed in this study. A mathematical method for nonlinear surrogate synthesis of excitation systems for frame moving tangential surface eddy current probes, which implements a uniform eddy current density distribution of the testing zone object, is proposed. A metamodel of the volumetric structure of the excitation system of the frame tangential eddy current probe, applied in the process of surrogate optimal parametric synthesis, has been created. The examples of nonlinear synthesis of excitation systems using modern metaheuristic stochastic algorithms for finding the global extremum are considered. The numerical results of the obtained solutions of the problems are presented. The efficiency of the synthesized structures of excitation systems in comparison with classical analogs is shown on the graphs of the eddy current density distribution on the object surface in the testing zone.

Background. Every day, every person is affected by a whole range of factors that are emotional and stressful in nature, which can lead to the appearance of oncological or cardiovascular diseases. It is known that up to 20 % of the world's population is prone to anxiety and depression, regardless of race, region and wealth level. The aim of the work is to develop and study an original algorithm for the complex processing and analysis of electroencephalographic signals in people under conditions of emotional arousal. Materials and methods. For the research, a sample of 30 subjects, aged from 23 to 28 years, was formed, who gave their voluntary consent to the experiment in accordance with the protocol of the clinical trial. Measurement of electroencephalographic signals parameters was carried out in a calm state, in a natural load and six modes of audiovisual stimulation (sleep, learn, energ, create, fun, special). To compare the obtained results, numerical methods of analysis were carried out: amplitude, spectral and correlation. Results and conclusions. As a result of the research, it was found that in the audiovisual stimulation mode with open eyes and energ, the process of excitation of the cerebral hemispheres is recorded, which indicates a pronounced picture of the emotional state. In the sleep and fun modes, stabilization of emotional stress is recorded.

Background. The accuracy of speech signal segmentation depends directly on the parameters used to determine the boundaries of the beginning and the end of informative fragments in a continuous speech stream. The purpose of the work is to increase the efficiency of speech/pause segmentation due to the frequency-time analysis of speech signals. The research object is the parameters that describe speech characteristics in the frequency and time domains. The research subject is the relevance of the informative parameters of speech signals to the task of speech/pause segmentation. Materials and methods. The methods of short-term analysis of spectral and energy characteristics of speech based on the discrete Fourier transform and the energy Teager operator were used in the work. Software implementation of the proposed method was performed in ©MATLAB mathematical modeling environment produced by Math- Works Results. A novel original approach to speech/pause segmentation based on the analysis of the values of the mean frequency (in the frequency domain) and short-term energy of the Teager operator function (in the time domain) is proposed. The proposed approach is unique due to an auxiliary algorithm to correct speech/pause segmentation errors, developed on the basis of physiological functioning of the respiratory apparatus organs during the formation of a continuous speech stream. A brief overview of speech signal informative parameters used for speech/pause segmentation has been presented, and the proposed approach performance has been detailed. The suggested approach has been compared with the known methods of speech/pause segmentation for pure and noisy speech signals. Conclusions. The research findings have evidenced the best results of speech/pause segmentation for pure and noisy speech signals being achieved by the methods based on the proposed approach; the ratio of the short-term energy of the Teager operator function to the mean frequency as an informative parameter ensuring maximum relevance to the segmentation problem; an auxiliary algorithm to correct false states enhancing the efficiency of segmentation.

Background. The most common cause of human disease is hypothermia of the body. This problem can be solved by using «smart» clothes with the ability to control temperature and adapt to the surrounding external conditions. The purpose of this work is to develop a prototype of «smart» clothing with remote control and temperature control. Materials and methods. When developing the device, preferences in the element base are given to the ESP-32 microcontroller with built-in transmission modules (Wi-Fi, Bluetooth). ESP-32 has the necessary characteristics: operating temperature, built-in thermal sensor, the ability to use the 1-Wire interface, support for Bluetooth Low Energy (BLE) protocol. To accurately determine the temperature outside the controller, sensors with high accuracy and a wide measurement range (±1 °C, from –55 °C to +125 °C), as well as the small dimensions of the DS18b20 case are selected. The LM317 stabilizer is used as a voltage stabilizer for the controller and sensors. All components are used in chip design to minimize the size of the device. Results and conclusions. Based on the results of the microelectronic design of the device, the sensors necessary for the minimum functionality were determined and an algorithm for the operation of the product was developed. The device has a small size (75 × 48 × 22 mm), powered by a powerbank with an output voltage of 5 volts and a current of at least 2.1 amperes, zonal heating temperature up to 40 °C. The operating time of the product with the heaters turned on is 8–10 hours, due to the control of PWM power keys, the time can be increased by reducing the degree of heating.

Background. The introduction of new technologies makes everyday life easier, but at the same time increases the impact on the human nervous system, which in turn negatively affects his health, quality of life and performance. The aim of the work is to develop a technique for monitoring and correcting the informative parameters of the physiological activity of the brain through the use of known and new original approaches to restore the nervous system under conditions of prolonged stress. Materials and methods. The paper provides an overview of systems for recording and correcting the parameters of the physiological activity of the brain, as well as a method for monitoring and correcting the physiological parameters of brain activity. It is proposed to use new and improved methods of digital processing of physiological signals of the brain to ensure automation of the signal analysis process by a doctor. Results and conclusions. A technique for monitoring and correcting the physiological parameters of brain activity has been developed, which ensures the registration of physiological signals of the brain in eight leads, storage and digital processing, analysis of informative parameters and decision making.

We discuss herein the differences both in composition and structure of the lithospheric mantle of the Siberian Platform under kimberlite fields of different ages. Having analyzed the pyrope garnets from kimberlites of different ages this study aimed to identify the genesis, extent and probable causes for the evolution of the composition and structure of the lithospheric mantle within various SP blocks. Acquired results revealed noticeable differences in the lithosphere thickness of different blocks for Middle Paleozoic and Mesozoic, as well as within the same time. It was found, that the greatest differences in the thickness of the lithosphere individual blocks are typical for the Middle Paleozoic. The results obtained for pyrope garnets from the Paleozoic sedimentary secondary collectors was used to get direct evidence on the existence of thick lithosphere blocks (230–240 km) under the southern margin of the Olenek uplift, north and south of the Kyutyungde trough, as well as under the western and eastern margins of the Udzhinsky uplift. Significant variations in the intensity and extent of silicate-type metasomatism were identified by investigating of pyropes from peridotites of the lithospheric mantle, sampled by kimberlites of both Middle Paleozoic and Triassic fields. Direct evidence indicates high prospects for discovering new fields of diamondiferous high-grade kimberlites of the Middle Paleozoic age in some areas of the Siberian Platform, primarily in its Arctic region.

It is important to study the relationships between tree growth and phenology and climate factors in Central Asia for the sustainable development of forest ecology and the exploration of carbon sink potential in the region in a context of global change. Herein, the process-based Vaganov-Shashkin model was used to simulate tree-ring growth rates, to assess a cambial phenology (start and end of growing season) of larch trees (Larix sibirica) based on three sites located on three different latitudes in the Altai-Sayan Mountains in Central Asia over 1960–2018. It was shown that the principal factor limiting growth rates was temperature in RU (located in southern central Siberia), cambial dynamic was unimodal. In RU site, although the length of growing season did not change significantly over the past 59 years, it was correlated with tree radial growth. Moisture was the principal factor limiting the growth rates of AL and FY (located in Chinese Altai Mountains), and cambium dynamics were bimodal and unimodal, respectively. Temperature and precipitation before the start of the growing season lengthen the growing season, but this did not promote the tree radial growth. In conclusion, we determined that the climate-influenced intra-seasonal growth rate regulated tree growth rather than length of growing season in this area. In this study, the VS-simulation showed high potential develop a long-term reconstruction of cambial phenology in the Altai Mountains, which was conducive to a more comprehensive understanding of the exogenous-endogenous factors effects on tree-ring growth.

A mathematical method for nonlinear surrogate synthesis of frame surface eddy current probes providing a uniform eddy current density distribution in the testing object area is proposed. A metamodel of a frame movable eddy-current probe with a planar excitation system structure, used in the algorithm for surrogate optimal synthesis was created. The examples of a nonlinear synthesis of excitation systems with the application of the modern metaheuristic stochastic algorithms for finding the global extremum are considered. The numerical findings of the problem analyses are presented. The efficiency of the synthesized excitation structures was demonstrated on the basis of the eddy current density distribution graphs on the surface of the control zone of the object in comparison with classical analogues.