The paper considers a structural model of a solid body. Yu. N. Malashkin proposed a structural model of concrete, the main idea of ​​which is an elementary volume in the form of a polyhedron formed from rod octahedra. When developing the model, only its analytical analysis was carried out. In this work, in the development of the model, its finite element analysis was carried out in the LIRA-SAPR software package. The study showed the coincidence of the qualitative and quantitative parameters of the model obtained by numerical and analytical calculations, confirmed its adequacy in relation to concrete.

Keywords: structural model, concrete, elementary volume, polyhedron, rod octahedron, finite element analysis, lira-sapr software package

The shear calculation scheme of a multi-storey building, popular in design practice, is considered.The application of the method of displacements is shown, when the mutual displacements of the floors of the frame are taken as unknowns. The indicated technique leads to the solution of the system of equations of the displacement method with the upper two-diagonal matrix, which makes it possible to obtain an analytical solution of the problem.

Keywords: shear calculation scheme of the building, move method, tridiagonal matrix, sweep method, reciprocal movements, analytical solution of the equation system

The article contains information about the factors influencing the attitude of consumers to tourist offers, and provides recommendations on the organization of an effective advertising campaign of a travel company belonging to the category of small and medium-sized businesses in the vastness of the global network.

Keywords: campaign, advertising, tourism, internet, website, direct, marketplace, query, statistics, Iran

The study evaluated the effect of the spring position in the panel on the amount of force required for vertical pushing of the columns. The results show that the farther the spring is from the hinge, the less pushing force is required to lift the column. In this method, the column was connected to the panel by hinged hinges at the factory, which allows lifting elements by crane as a single group during the installation of the frame structure on the construction site. In addition, a spring is installed on the panel at a certain distance, helping to push out the column and secure it. In this article, a threaded connection of precast reinforced concrete columns is proposed, which can be used to connect elements of fully assembled buildings and structures. The contact-screw connection of precast reinforced concrete consists of an upper and lower column, both have a cylindrical steel external thread in the end section connected. The strength of the screw column connection is determined by ensuring the transmission of axial loads and torque in the joints, ensuring the destruction caused by cutting and thread confusion that may occur between the connected columns. By means of the necessary calculations for the screw connection of columns made of precast reinforced concrete the corresponding rigidity and strength were confirmed. The new connections will contribute to the development of construction, its energy efficiency and acceleration of the installation process. These are effective approaches to reducing effort, time, and labor and energy costs.

Keywords: prefabricated buildings, passive assembly, column connection, screw connection, energy efficiency of installation, mounting spring, hinge loop

The geographical location, tectonic and geological-hydrogeological structure of the Maly Liman Lake basin, its landscape features as a natural monument of regional significance located on the area of the Abraus Peninsula of the Krasnodar Territory were described. The results of current bathymetry studies of the lake were shown. The hypothesis about tectonic origin of its hollow was justified. The sedimentations of the Maly Liman and Abrau lakes were tested and their description was fulfilled. By using radionuclide analysis the sedimentation rates were determined. Expedition work was carried out and a description of the outlets of the perched waters was made. The water balance development models of the of the Maly Liman Lake in the conditions of arid and relatively full-water period were constructed. The perched water dynamics of the upper reaches and surface run-off as the dominant supply sources of the lake was described. A hydrogeological section was constructed along the section of Lake Abrau – Lake Maly Liman. The existence of their hydraulic connection was proved, as well as the presence of two aquifers – the perched water and groundwater.

Keywords: Maly Liman, Limanchik, Abrau, water balance, sediment layers, bathymetry, ground waters, underground drain, mineralization, sedimentations

The work updates a strategic approach to maintaining the quality of student performance. In the article "Big Data" is presented as an approach to organizing the data obtained during the educational process. Mining analysis as a Big Data analysis tool. The authors also considered approaches to improving the effectiveness of learning, which allow predicting student performance. Blended learning, as an integration into the educational process, the best opportunities for online and distance learning, provided for the subsequent collection of Big Data for analysis. The application of data mining methods for the development of models for predicting the behavior and academic performance of students is considered. The authors propose student modeling as a key concept in data mining in education, which refers to the qualitative representation of student behavior. Algorithms for data mining are described, classification and clustering are presented as the most common tasks. The CART decision tree algorithm is presented as one of the effective data mining methods needed to predict student performance based on online activity that is stored in the Moodle LMS log file. Finally, it was concluded that the personal contact of an experienced teacher with a student in the educational process can not be replaced by the tools provided by Moodle and similar systems, but due to the growing threats caused by the pandemic, the relevance of distance education is becoming increasingly important.

Keywords: student performance quality, big data, data mining, student modeling, CART decision tree algorithm, Moodle LMS, distance education

The electrophysical and mechanical properties of a piezoceramic material based on CTS are investigated. A number of features in the behavior of the electrophysical properties of the material in the temperature range located significantly below the low-frequency (1 kHz) maximum of the dielectric constant T_m = 160℃ have been revealed. The obtained results indicate the proximity of the studied material to ferroelectric relaxors, in particular, the low coercive field E_c~5 kVcmcm, the significant dependence of T_m on the frequency and amplitude of the measuring field, as well as the behavior of the velocity of longitudinal ultrasonic waves in this ceramic. It is shown that the elastic properties of this material are very close to ferroelectric relaxors, having a high malleability in a very wide temperature range. At the same time, the squareness of the polarization loops at relatively low temperatures indicates the manifestation of the classical properties of the ferroelectric during the polarization switching processes, and not the "freezing" processes characteristic of ferroelectric relaxors. From the results obtained, it can be established that this composition will be promising for use in the actuators of adaptive optics systems and precision positioning devices due to the high values of piezomodules.

Keywords: PZT system, ferroalloy ceramics, dispersion, polarization, elastic properties, blurred phase transitions, curie temperature, depolarization temperature, ferroelectric relaxor, rhombohedral phase, tetragonal phase

This article presents one of the methods for analyzing the chirality coefficient of a medium depending on such parameters as concentration n, frequency f, dielectric constants of both the container material, the medium itself, and left- and right-handed spirals distributed in this material. As a result of this work, the frequency characteristics of the chirality coefficient were obtained at various concentrations of the container trace elements.

Keywords: chiral medium, Telledzhene element, chirality coefficient, dielectric constant of the medium, magnetic permeability of the medium, spiral structure, metamaterial substrate, bulk concentration, metamaterial, spiral inclusions

The article is devoted to the development of models and algorithms for calculating control (advisory) actions when training operators of technological processes (on the example of reloading processes and, in particular, portal cranes) on computer training complexes (CTC). A complex of models and algorithms is proposed, based on which control actions are calculated regarding discrete crane controls and the possibility of moving the load to a target position with minimization of oscillations at the end point is provided. These models and algorithms use variable parameters of the technological process, described by linguistic variables, and customizable characteristics of crane models and engines, which allows calculating control actions depending on the type of crane, the specifics of the technological process, the training methodology used for operators and other significant factors. Application of the advisory system based on the developed models and algorithms promotes to improve the training process for operators of reloading cranes at CTC and, as a result, to reduce the probability of emergency situations, reduce time and energy costs.

Keywords: computer simulator, reloading processes, portal crane, advisory system, control actions, mathematical modeling, fuzzy logic controller

The paper considers the quasi-stationary motion of a viscous compressible fluid in the gap of a thrust bearing with a nonlinear contour of the support surface of the slider. It is assumed that the slider is stationary, and the guide with the molten surface moves in the direction of narrowing the gap at a time-dependent speed. Well-known equations are used for the solution: the equation of motion of a compressible fluid, the equation of continuity, the equation of state and the equation describing the profile of the molten contour of the support ring. The case is considered for the extreme and non-extreme case, that is, when the parameter of the specific heat of melting tends to infinity and vice versa. As a result of an accurate self–similar solution, the main operational characteristics are determined - velocity and pressure fields, load capacity and friction force. The problem of the stability of the movement of the support ring is also solved. The final stage of theoretical calculation methods is numerical analysis.The analysis of its results showed that the modified design of the thrust sliding bearing, taking into account additional factors, has a bearing capacity value exceeding the standard designs by 8-11% in the range of load-speed modes studied. The coefficient of friction is reduced by 9-13%.

Keywords: quasi-stationary flow, extreme case, metal coating, non-standard support profile, hydrodynamic mode, stability of the guide movement

The effect of a zeolite support on the physicochemical properties of cobalt catalysts was studied on a series of samples with zeolites ZSM-5, HY, and NaX. The catalysts were obtained by precipitation followed by mixing the precipitate with a zeolite support. Their properties were characterized by BET, TPR, TPD-H2, IR spectroscopy. The results of the analysis show that the type of zeolite support affects the specific surface area, reduction of deposited cobalt, and the structural properties of the active component of catalytic systems.

Keywords: precipitated catalyst, cobalt, zeolite, dispersion, specific surface area, active component, synthetic fuel, degree of reduction

When developing the final qualifying paper the problem of choosing the optimal structural concept for bearing and enclosing structures. To solve it, normative technical and economic indicators, variant comparison (trial design) and other methods can be used. The objective of the present study, which is carried out as part of the final qualifying paper, is to search for and develop an algorithm that is understandable for practical use for choosing an effective (in terms of specific consumption) structural concept for a steel truss.

Keywords: optimization, specific consumption, cost value, steel truss, steel structure design, STARK ES, analysis of trusses, optimal structural concept, changing the section type, selection of an effective structural concept

The article discusses the basic principles for choosing multi-purpose design solutions for construction production during a forensic construction and technical expertise, and also presents an algorithm for solving problems of this type. Based on the interpretation of the results of theoretical work and the analysis of judicial practice, a method was obtained that can be used in the conduct of judicial construction and technical expertise to solve the problems of choosing design solutions and materials.

Keywords: judicial construction and technical expertise; building production; design solutions; construction expert; mathematical modeling

It was necessary to develop a filter design option for implementing it on an FPGA in conditions of limited FPGA resources and processing time. Options for constructing filters and sequential optimization of the structure for implementation on an FPGA were considered. Two models were built using the Matlab environment, where the results of signal processing with filters were compared for the same parameters. Simulations have shown that the filters are unique.

Keywords: DSP, FIR filter, pipeline, FPGA

The simplest, most reliable and sufficiently accurate method of dosing bulk products is batch dosing by volume using measuring containers. The article considers a mathematical model of a volumetric dispenser. The combination of several methods of regulating the supply of bulk materials during batch dosing is ensured by building an accurate model of the drum dispenser.

Keywords: mathematical model of a drum dispenser, dosing process, friction, dynamic coefficient of friction, static coefficient of friction, bulk material