The article describes four developed designs of samples of joints of solid wood elements on aluminum linings. They made it possible to simulate the operation of real connections of the main and secondary beams, as well as crossbars and columns. Tests of connection samples were carried out, one of the four developed variants of sample designs was selected that most fully reflects the actual work of real joints of wooden elements. The strength and deformation characteristics of the joint, the upper boundary of the elastic work area (VGOUR) of the joint are determined. Based on the conducted research, the peculiarities of the work of the studied compounds were determined, a sample of the connection of a wooden element with a metal overlay was developed, which allowed the development of measures aimed at increasing the bearing capacity and reducing the deformability of the studied compounds without significant material costs associated with the purchase of expensive SHERPA linings.

Keywords: solid wood, metal slips, testing of joint specimens, joint bearing capacity, joint deformability, upper limit of the elastic work region, full deformation, permanent deformation, elastic deformation, safety factor

3D integration technologies based on highly integrated substrates and bare chips solve the problem of miniaturization of complex functional devices. However, increasing complexity and decreasing mass-size parameters of products lead to problems of effective heat distribution and dissipation from frameless microcircuits. The article considers features and problems of thermal analysis of 3D computing microsystem based on several modules with bare-metal chips, and also shows the importance of modeling the actual heat generation of programmable logic integrated circuits.

Keywords: microassembly, microsystem, chipless chip, FPGA, thermal analysis, CAD, finite element method, heat transfer simulation, printed circuit board, three-dimensional integration

To date, the issue of industrial development of the Northern territories of Russia is being actualize. The main task is the production of concrete works that require the use of special methods. The purpose of the current article is to justify the need to develop a software solution that allows you to automate the calculation of the pa-rameters of the heating wire during winter concreting. The author raises the ques-tion of the relevance of using the method of winter concreting on the example of heating wires. The paper analyzes aspects of the design of this program. The scien-tific significance of the article lies in the possibility of using the presented materials as a basis for creating a real software solution. The predominant part of the article is devoted specifically to the issues of creating a solution for automating the calcu-lation of heating wire parameters during winter concreting.

Keywords: construction, program, automation, heating wire, winter concreting, the Far North

The article considers an experimental study of the stress-strain state of radial beam domes. The maximum stress values are fixed in stretched flexible elements with a peak value of 363.6 MPa. With the calculated resistance of the wire material Bp-I Rs = 410 MPa, there is a 12% load-bearing capacity margin. Note the high level of stresses in other flexible elements with values in the range from 141.4 to 274.72 MPa.

Keywords: radial beam dome, experimental studies, loading, strain gages, deformation

The paper presents the properties and nomenclature of products made of ceramic fiber used for insulating lining in steam reforming furnaces. On the example of the lining of the radiant chamber, the technology of mounting ceramic blankets on anchor studs, which is currently used in the construction and repair of reforming furnaces, is considered. The shortcomings of the existing technology are noted. These include the complexity of the process, the complexity of installation control and the high probability of uneven thermal conductivity of the lining surface due to hidden defects, as well as the spraying of ceramic fiber particles in the air that cause diseases. The nomenclature and technology of installation of insulating lining with ceramic blocks along guide tubes with subsequent resistance welding with the camera body is proposed. The technology will reduce the repair time, improve the thermal conductivity of the camera, reduce the risk of diseases.

Keywords: gas reforming, radiant chamber, insulation lining, ceramic fiber, thermal conductivity of the furnace

The paper considers a mathematical model of the ion-beam etching process. A nonlinear differential equation of first-order ion-beam etching is considered. It has been established that the model equation for ion-beam etching can be reduced to a homogeneous Monge-Ampere equation. Some classes of exact solutions are presented for this equation. A power-law solution is obtained by the method of functional separation of variables, which depends only on a set of constants and does not contain arbitrary functions. Solutions are also found that linearly depend on arbitrary functions of the coordinate variable and the time variable. Assumptions and explicit conditions are formulated on how to select solutions from the families of solutions of the Monge-Ampere equation that correspond to the model process under consideration. A class of nonlinear equations in partial derivatives of the first order is indicated, which can also be reduced to the Monge-Ampere equation. Limitations on the etching rate are established, which allow the ion-beam etching equation to be reduced to a second-order linear hyperbolic equation, for which, by separation of variables, it is possible to obtain a solution in the form of a Fourier series.

Keywords: ion-beam etching equation, Monge-Ampere equation, model solutions, exact solutions

The paper discusses the use of machine learning in relation to natural language processing (sentiment analysis, semantic proximity analysis) to build a recommendation system for the choice of perfumery products. The topic of the work is relevant in view of the growth of the range of manufactured perfumery products and the complexity of its choice by consumers and promotion by manufacturers. The proposed approaches are relevant for solving this problem due to the accumulated textual reviews and reviews of perfumery products on various websites, including online stores.

Keywords: machine learning, natural language, sentiment analysis, distributive semantics, word2vec, recommender systems

The issue of changing scientific interest in the methods of combining images in technical systems is considered. The material is based on the analysis of open publications, patents presented in the scientific electronic library eLibrary for the period 1980 – 2021, as well as not included in it for any reason. The types of sources for formation of image, goals and features of the most common ways of combining are considered. The areas of preferential use methods of combining are given. The issues of image preprocessing to increase the informativeness of the result of the combination are considered.

Keywords: visual data, foundation image, image combination, information combination, image preprocessing

Pipe fittings, which are one of the main elements of any type of pipeline networks, can be used for various purposes: shut-off, reverse, safety, control, separating, shutting off, etc. In order to control the performance of this element, it is necessary to carry out various tests in the prescribed manner, the main ones being pneumatic. This study is devoted to the development of equipment for in-plant pneumatic testing of rotary check valves for pipeline systems of hazardous production facilities with ultra-high parameters of the working environment. For this design of the installation, the simulation of the stress-strain state of the elements of the installation was carried out, as well as the gas-dynamic calculation of the test circuit of the installation.

Keywords: rotary check valve, pipeline fittings, pipeline system, mathematical modeling, finite element method, strength analysis, stress-strain state, computational fluid dynamics, pneumatic testing, technological pneumatic installation

In industrial production, stacker loaders used for loading and transporting goods packed on pallets are quite widely used in warehouse work. Basically, when performing a loading and transport technological operation, the functionality of the stacker is sufficient. When an obstacle appears or pallets are stacked, additional maneuverability is required, as a result of which the overall performance of the loader is lost. As a result of the conducted research, it was found that when bypassing obstacles and laying pallets, the time spent on maneuvering the chassis is up to 13%, while the utilization factor of the loader-stacker in terms of productivity is 0.7. Numerical modeling of the positioning process of the load-handling body of the loading and transport unit was carried out, on this basis, the design of a loader-stacker with expanded functionality was proposed and developed, in particular, the service area increased due to the use of a tripod manipulator and two guide actuators, which reduces the time of the technological operation of loading and unloading pallets in warehouse work. Geometrical, structural and kinematic parameters of the loader mechanism are calculated.

Keywords: numerical simulation, loader-stacker, service area, lifting body, manipulator, hinges, chassis, structural analysis, geometric analysis, kinematic analysis, executive drive, pallet

The article discusses various mechanisms of self-healing of concrete used in the construction of buildings and structures designed for certain operating conditions and the environment, which saves resources and time during maintenance and repair of objects for various purposes. Types of self-healing of concrete: With hollow fibers; Microcapsulation; Expanding additives; Bacteria. Conclusions. Today, progress has been made in understanding the relationship between the structure of materials and their properties. Thanks to the knowledge gained about the structure of materials, the possibility of designing materials of directional quality was considered, which guarantees their compliance with certain operating conditions and the environment.

Keywords: concrete, destruction, self-healing, hollow fibers, microcapsulation, expanding agent, bacteria

The construction of public buildings from a metal frame is always associated with the search for a rational constructive solution that meets not only the dependability requirements, safety, but also architectural and design solutions. Often, the solution to the problem of rationalization of roof construction in public buildings is the use of arched combined systems, since such systems have a number of advantages over simple arches: the survivability of combined systems is higher than simple ones, the possibility of creating complex, architecturally expressive spatial structures, lower material consumption, high load-carrying ability with relatively low weight, etc. The aim of the research is to find a rational construction solution for two arch-cable systems (Hud type system and Radial type system) by comparing in terms of the minimum internal forces, displacements and metal intensity at different ratios of the arch boom and span. Based on the calculation results in the Lira SAPR 2020 software, the most unfavorable loads combinations were determined, deformation schemes of arch systems, displacements, moments and forces were obtained, sections of arches and ties were selected. From ten arched structures of two types considered with different ratios of arch boom to span, the Hub type system with the ratio of arch boom to span f/L = 1/3 and Radial type system with the ratio of boom to span f/L = 1/4 showed the best result in terms of efficient operation and metal intensity.

Keywords: combined systems, arch-cable constructions, simulation of prestress, hub type s

This arcticle are devoted to the modernization of housing and communal system based on the technology of "Smart Grids". The methology of developing an assessment of the effectiveness of the project of the modernization of housing and communal services facilities using the technology of "Smart Grids" is given. It from the publication that the use of "Smart Grids" technology provides energy and economic efficiency in the development of the city's energy system

Keywords: Smart grids, "Smart City", centralized heat supply systems, individual heat supply, evaluation of the economic modernization project, key performance indicators

The system for measuring cargo dimensions is designed for streaming measurement of cargo dimensions, which can be luggage at airports and transshipment bases, various parcels, as well as commercial cargo. The authors of the article developed a structural and functional diagram of a control and measuring system for dynamic measurement of cargo dimensions, and also considered the principles of its operation.

Keywords: control and measuring system, measurements, cargo dimensions, luggage, automated systems

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