The article considers one of the problems hindering the use of ceramic piezoelectric materials based on the BiFeO3 - BaTiO3 phases, which is caused by high values ​​of the dielectric loss tangent of these materials. It is assumed that this is due to different electrical conductivity of individual grains of this type of piezoelectric ceramics (Maxwell-Wagner effects), caused by the presence of iron ions in their composition, which have different oxidation states. In order to equalize the oxidation states of iron ions found in the grains of the considered ceramics, we used annealing of its samples in an atmosphere formed as a result of thermal decomposition of ammonium carbonate. It was found that this technique allows: a) to reduce the values ​​of tgδ of the CPM by 6 - 7 times; b) increase the polarizing field strength by at least 40%, and the value of the longitudinal piezoelectric modulus to 140 pC/N.

Keywords: piezoelectric material, electrical conductivity, dielectric loss, defect, iron ions, Maxwell-Wagner effect, reducing atmosphere, ammonium carbonate

The article examines the two-dimensional flow around rectangular cylinders with an aspect ratio from 0.1 to 2.0 using the k-Realizable turbulence model with a Reynolds number of 2×E5. Numerical calculations in the ANSYS Fluent program have obtained changes in the coefficients of drag, transverse force and the Struhal number depending on the size of the prism section. The calculations were carried out at the intensity of turbulence of the incoming flow 2% and 4%. According to the results of calculations, it was found that with turbulence 4%, there is a good coincidence of the total aerodynamic characteristics with the available experimental data.

Keywords: flow around a rectangular cylinder, k-e Realizable turbulence model, aerodynamic characteristics of a rectangular cylinder

The architecture of multifunctional residential complexes (MFRC) is considered in the aspect of “resistance” to external factors and influences. There are four levels of formation of the MFRK: the level of urban planning structure; level of volumetric-spatial organization; level of functional and architectural planning structure; the level of compositional organization and search for the expressive appearance of the MFRK. At each of the identified levels, the “target” indicators of “sustainable architecture” are achieved. The process of forming the MFRC is considered as a sequence of combinatorial search stages and procedures based on modeling the geometric parameters of the visual model of the MFRC in order to get as close as possible to the “stability indicator”. Four methods of combinatorial search modeling are proposed: the method of “overlaying” planning frames; method of “tracing” the formative contour; method of “collaging” functional planning elements; a method of combining “regular grids” in the public, business and residential parts of the MFRK. To intensify combinatorial search procedures, it is proposed to use digital design technologies.

Keywords: university complex, transit urban spaces, scenario approach, functional-thematic zones, architectural and environmental modules

Wood as a building material has ancient roots and a long history of use. With the development of technology and the desire to live in better environmental conditions, interest in using wood to construct multi-story buildings is growing. This article is devoted to the prospects for the development of wooden multi-story buildings in Russia, in particular with the use of CLT panels, the popularity of which is growing all over the world. Comparative, statistical and logical analyzes were used as research methods. The article discusses modern methods and technologies for the construction of multi-story wooden buildings, including their advantages in terms of ecology, energy efficiency and design, conducts a comparative analysis of buildings made of reinforced concrete and CLT panels, and proposes a technological scheme for the reconstruction of buildings using CLT panels, including adding additional floors. Challenges and prospects for further development of this technology are highlighted, strategic solutions are proposed to reduce the cost of CLT panels

Keywords: clt-panels, wood construction, wooden structures, reconstruction, renovation, high-rise wooden construction

With the development of scientific and technological progress, the use of modern data forecasting methods is becoming an increasingly necessary and important task in analyzing the economic activity of any enterprise, since business operations can generate a very large amount of data. This article is devoted to the study of methods for forecasting financial and trade indicators using neural networks for enterprises of the Krasnodar Territory. The indicators under consideration are the company's revenue for the reporting period, the number of published (available for sale) goods, as well as the number of ordered goods during the day, week and month. In this study, a multilayer perceptron is considered in detail, which can be used in revenue forecasting tasks using neural networks, and neural network predictive models "MLP 21-8-1", "MLP 21-6-1", and "MLP 20-10-1" are built based on data from the online auto chemistry store Profline-23.

Keywords: automated neural networks, marketplaces, forecasting, neural network models, mathematical models, forecasting methods

The article deals with the problem of education and management of construction waste. The data on the increase in construction volumes and, as a result, an increase in the amount of waste in Russia are presented. The main sources and types of construction waste are analyzed, their classification according to the degree of danger. Traditional and modern methods of waste disposal, such as burial, recycling, incineration, are discussed. The conclusion is made about the need to improve environmental culture in the construction industry and improve waste management legislation.

Keywords: construction waste, construction debris, waste disposal, recycling, environmental culture, waste legislation

With the rapid development of technology and the widespread use of video surveillance, modeling the architecture of neural networks for human recognition in video is attracting increasing attention from researchers. This article presents a study of the use of neural networks (NN) as an interdisciplinary model for classifying objects in video, including solving the problem of face search. This highlights the versatility of neural networks in integrating trained data and accurately classifying objects, which is critical for ensuring security and efficiency of video surveillance. The study uses an analysis of various neural network architectures, as well as a study of their operating algorithms. Data obtained from a literature review and experimental results allow us to evaluate the effectiveness of solving the task of classifying objects in video using various architectures, without tying the study to a specific data set. The study confirms the possibility of using modern neural network architectures for human recognition in real-time video based on the experience of experts in the field of computer vision and machine learning. The active use of neural networks as a tool for video surveillance increases the safety of infrastructure facilities and the efficiency of security services. Ultimately, this article presents an analysis of neural network architectures for facial recognition in video streams, advocating their use as a key element in the development of modern video surveillance systems and ensuring public safety.

Keywords: neural networks, neural network architectures, video surveillance systems, real-time recognition, improving security, social well-being

Expert work has been carried out to establish quality indicators for three types of concrete paving slabs: "Auriko", "Paving stone", "New City". The tests were carried out on selected samples in accordance with GOST 17608-2017. According to the test results, it was determined that only the samples of "Paving stones" tiles meet the requirements of GOST, other types of tiles revealed non-compliance of the studied samples with GOST 17608 in terms of water absorption and frost resistance.Frost resistance tests for Aurico and Novy Gorod product samples were interrupted after 15 freeze-thaw cycles due to the destruction of the samples.

Keywords: paving slabs, concrete, compressive strength, frost resistance, surface defect "sink"

Eye tracking (oculography) is a technology that allows recording the direction of human gaze on a visual stimulus. It’s application can provide researchers with valuable data on which elements of the environment are most attractive in various contexts, in areas such as marketing, psychology, etc. The aim of this work is to identify the pattern of human attention distribution on visual stimulus objects of different sizes using eye tracking technology. A webcam was used to record the subjects’ gaze movements while they were studying experimental images. The results of the experiments showed that larger objects in visual stimuli receive higher attention priority than smaller objects. This observation is true for both human-created works and images created by artificial intelligence (Kandinsky 3.1 is used in this study). The obtained results of the study will improve our understanding of how people perceive visual information, which can contribute to the creation of more effective approaches to interface development.

Keywords: eye tracking technology, attention priority, region of interest, number of eye gaze registrations, artificial intelligence, Vincent Van Gogh

To develop a methodology for assessing the strength of ring flanges, research was conducted on the load-bearing capacity of welded pipe joints of varying diameters. The study employed the component finite element method (CFEM) implemented in the IDEAStatiCa Connection software. To verify the obtained results, a numerical experiment was carried out using the ANSYS software package. The investigation considered several types of flange joints made from welded pipes with different diameters. Parameters were selected based on common sections used according to russian Series 3.400-8 (Issue 2). The study found that for all cases, the highest stresses occurred on the flange at the joint with the smaller diameter pipe. The analysis indicated that the CFEM's applicability should be limited to diameter-to-wall-thickness ratios (D1/t1) of up to 40. Beyond this threshold, the CFEM does not accurately predict the strength of the joints due to the significant deformation that occurs in the pipe walls, forming a truncated cone shape at the flange junctions. For practical applications, formulas are proposed to check the strength of ring flanges. These formulas account for the weakening of the plates by bolt holes and provide conservative results. The findings highlight the necessity for additional numerical and physical experiments to refine the methodology for cases with D1/t1 ratios exceeding 75. The proposed approach offers a practical solution for evaluating the strength of ring flanges in welded pipe joints of varying diameters, contributing to the development of relevant engineering standards.

Keywords: load-bearing capacity, ring flanges, welded pipes, assembly joints, strength, component method, numerical experiment

Framed fabric roof structures of the sawtooth-type are considered. The structures are arranged on rectangular plan. They consist of a number of sectors which are separated by arch-shaped supporting ribs. The sectors are covered with a prestressed soft shell. Geometric nonlinear static analysis of the shell is performed taking into account the effect of snow and wind loads. The general dimensions of the shell and the prestress value are considered as the primary variables. Quantitative assessment of deformation of the shell is carried out by means of so-called deformability index. The index is reciprocal to the relative deflection. A functional expression for approximating the deformability index is proposed. The expression is to be used at the stage of developing the design solutions for fabric structures. The coefficients of the function are found by means of the least squares method. The guidance for assigning the main parameters of the sawtooth-type fabric structures are given.

Keywords: fabric structure, roof structure, soft shell, sawtooth roof, geometric parameters, prestress, deformability, approximation

The article considers a variant of constructing a digital twin model for diagnostics of operation of a mechanical gear transmission - a reducer consisting of a pair of cylindrical gears. The basis of the considered digital twin model is an adaptive learning vibration mathematical model of the static operating mode when gears rotate at a constant speed. The vibration signals of the reducer, recorded by accelerometers and effective for detecting and diagnosing faults, are used as the main information measured at the facility. The detected faults are cracking, wear, chipping and pitting of teeth. A special feature of the implemented digital twin is the ability to simultaneously detect faults of several teeth at once, both on the driving and driven gears, by time and frequency characteristics, as well as the ability to determine the main technical data of a specific reducer by vibration characteristics.

Keywords: diagnostic mathematical model, digital twin, vibration diagnostics, mechanical gearbox, tooth defect, diagnostic signal, vibration power spectrum, synchronously averaged time characteristic

Stepper motors are often used in automated laser cutting systems. The control circuit of a stepper motor requires a special electronic device - a driver, which receives logical signals as input and changes the current in the motor windings to provide motion parameters. This research study evaluated stepper motor drivers to determine the feasibility of their use - PLDS880, OSM-42RA, OSM-88RA. To control the system, software code was written, which was connected to the controller via a link board. With each driver, in different modes, optimal parameters were selected (initial speed, final speed and acceleration), that is, the movement of the carriage without stalling for ten passes with a minimum travel time. The results of the experiments are presented in the form of tables.

Keywords: laser, laser cutting, automation, technological process, stepper motor, performance, driver, controller, control circuit, optimal parameters

The article considers the solution of the urgent problem of calculating the size of the effective focal spot of a microfocus X-ray tube using computer modeling methods. The principle of operation of the calculation method used by the authors is to compare interference images obtained using tested microfocus X-ray tubes with simulated interference patterns formed using the developed software by numerically solving the wave equation. It should be noted that modeling a one-dimensional interference pattern using fast Fourier transform requires a significant amount of RAM and takes considerable time even when using modern computer equipment. The paper presents the results of modeling phase contrast profiles for two types of test objects – nylon fishing line and aluminum wire. The considered method for determining the size of the focal spot is characterized by good sensitivity and allows efficient and high-precision calculations for all types of microfocus X-ray tubes.

Keywords: computer modeling, X-ray tube, microfocus source, focal spot, non-destructive testing

The article analyzes modern approaches and technologies for recycling and recycling of building materials. Such types of waste as reinforced concrete, brick, glass, wood, plastic, etc. are considered. Special attention is paid to innovative methods of processing to obtain secondary raw materials (recycling). It is shown that the most promising technologies are the crushing of concrete, brick and reinforced concrete for reuse in construction, the melting of scrap metal, glass and plastic, the processing of wood waste into slabs and fuel. There is an insufficient level of application of innovative solutions in Russia. A set of measures has been proposed to improve the efficiency of construction waste disposal: the introduction of advanced technologies, the construction of waste recycling plants, the adoption of a targeted state program, and the improvement of environmental culture.

Keywords: waste, construction debris, Russia, secondary raw materials, reuse, environment, recycling, burial, recycling