Currently, a large amount of research is devoted to the use of polymer composite materials applied for increasing the strength and durability of reinforced concrete elements. In compressed reinforced concrete columns, the bearing capacity depends on the eccentricity of the external force application and the corresponding stress-strain state, as well as on the arrangement and quantity of composite materials bonded to the surface of the structure. The choice of the arrangement scheme of composite materials depending on the stress state of the structure is of current interest for researchers. At the same time, studies conducted on centrally compressed elements often have contradictory effects. The main purpose of this study is to perform numerical experiment of a digital model for the centrally compressed concrete column reinforced with composite materials. The calculation results for 3 short columns with different reinforcement schemes are presented. It is shown that the use of composite materials to reinforce structures increases the bearing capacity up to 10%. Based on the study results, recommendations on the optimal schemes of reinforcement with composite clamps of inflexible columns reinforced in the transverse direction are proposed.

Keywords: reinforced concrete columns, normal sections, finite element modeling, reinforcement with composite materials

The article presents the results of the calculation of a high-rise building, the load-bearing frame of which uses wooden structures. With a significant height of the structure, wind load begins to have a significant impact on the deformability of the frame. A calculation scheme is proposed, in which two options for applying wind pressure are considered - on columns and in floor beams.

Keywords: high-rise building, permanent loads, short-term loads, instantaneous loads, modulus of elasticity, stiffness, stress, displacement, CAD

The new socio-economic and political conditions of the North Bulgarian Renaissance (1762-1878) determined the way of life, the nature of relationships in society, and its material environment. The object of their influence was primarily residential development, which revealed a variety of architectural forms. Their volumetric and planning features are determined by new ideological and artistic views. At the same time, unity is revealed in architectural diversity, predetermined by local natural and climatic conditions, sustainable construction technologies, and the revival of ancient spiritual and historical and cultural traditions. This article analyzes the development of techniques for the architectural organization of a residential building in the context of settlement and chronology.

Keywords: Bulgarian Renaissance, natural conditions, socio-economic factors, historical background, natural landscape, space-planning schemes, residential architecture

The article examines the epoch-making buildings of the city of Nalchik, which include the educational campus (LUG) and Stalin's dacha. The work provides historical information on these objects, architectural, artistic and planning solutions, their significance for the city. The main purpose of epoch-making buildings, according to the authors, is to preserve these objects for citizens and residents of the republic, as the historical and cultural heritage of the people, which must be recreated for future generations and preserve the recognizable unique image of the city.

Keywords: architecture, epoch-making buildings, facade, plan, building, school, Stalin's Dacha, Dacha N5, bay window, gazebo, brick, brick-wooden house

Reinforced concrete flat slabs continue to be one of the most popular floor systems due to the speed of construction and their inherent flexibility in the layout of the premises. However, flat, non-rigid floors are subject to brittle fracture at the junction of the slab and column, which can spread and lead to the progressive collapse of a larger segment of the structural system. The lack of shear strength in two directions may be due to design errors, insufficient strength of the material, or overload.

Keywords: reinforced concrete slab, punching, transverse reinforcement, fiberglass, carbon fiber

Road surface quality assessment is one of the most urgent tasks in the world. To solve it, there are many systems that mainly interact with images of the roadway. They work on the basis of both traditional methods (machine learning is not used) and machine learning algorithms. Traditional approaches, for example, include methods for edge detection in images that are the object of this study. However, each of the algorithms has certain features. For example, some of them allow to get a processed version of the original photo faster. The following methods were selected for analysis: "Canny algorithm", "Kirsch operator", "Laplace Operator", "Marr-Hildreth algorithm", "Prewitt operator" and "Sobel Operator". The main indicator of effectiveness in the study is the average time to receive the processed photo. The initial material of the experiment is 10 different images of the road surface in 5 sizes (1000x1000, 894x894, 775x775, 632x632, 447x447) in bmp, jpg, png formats. The study found that the "Kirsch operator", "Laplace Operator" and "Prewitt Operator" and "Sobel operator" have a linear dependence of O(n), the "Canny algorithm" and the "Marr-Hildreth algorithm" have a quadratic character of O(n2). The best results are demonstrated by the "Prewitt Operator" and the "Sobel Operator".

Keywords: comparison, effectiveness, method, edge detection, image, photo, road surface, dependence, size, format

The laboratory base in higher educational institutions should be equipped with modern stands with equipment that corresponds to the technological level of the real equipment of industrial enterprises. Practical training of highly qualified engineering personnel in the field of industrial automation is one of the key factors in the technological development of the material production sectors of our economy. The formation of students' skills required by the real sectors of the economy is possible only during practical and laboratory classes using laboratory stands based on modern domestic equipment. The article discusses the issues of designing and constructing a mobile multifunctional laboratory stand for the industrial automation based on the programmable logic controller of the national production SPK110, provides a functional diagram and wiring diagram of the laboratory stand, provides a complete list of electrical components used to create the stand. The performed economic assessment of the manufacture of the laboratory stand gives grounds to conclude that it is economically feasible to produce such stands by the staff of the departments of industrial automation. The article also shows the experience of introducing this laboratory stand into the educational process of bachelor's degree preparation in the direction of 15.03.04 “Automation of technological processes and productions". The laboratory stand based on the SPK110 is a multifunctional, mobile stand designed to implement multi-level tasks of industrial automation, which can also be used as a visual aid when conducting career guidance and exhibition events in extracurricular premises. The project to create the laboratory stand can be scaled up in other higher educational institutions of our country without spending time on the preparatory and research parts.

Keywords: programmable logic controller, laboratory stand, industrial automation, automation of technological processes and productions

This paper is devoted to optimization of surface acoustic wave bandpass filters with apodized interdigital transducers (IDT). Iterative Parks-McClellan algorithm is applied to estimate the apodization coefficients of the IDT fingers. A family of corresponding subroutines is developed in the Matlab mathematical package. The simulation results of the SAW filter optimized design are illustrated. For the refined estimation of the filter frequency response COM-based P-Matrices are employed. The results obtained in this study constitute a set of tools for the practical calculation of apodized IDTs and filters according to a given specification. Subroutines implementing COM-based P-Matrices can be utilized as part of programs for frequency-selective SAW devices design.

Keywords: acoustoelectronics, apodization, approximation, interdigitated transducer, impulse response, surface acoustic wave, optimization, piezoelectricity, filter, frequency response

The article discusses the author's methodology for designing and developing a test data generation tool called "QA Data Source", which can later be used in software testing. The paper describes the basic requirements, application functionality, data model, and usage examples. When describing the application, methods of system analysis and modeling of information processes were used. As a result of the application of the proposed model for the implementation of information processes, it is possible to significantly reduce the time and resources for generating test data and subsequent product testing.

Keywords: quality assurance, software testing, test data, information technology, data generation, databases, application development

The article considers the problem of sediment formation, sludge and corrosion on the heat transfer surface during the operation of heat exchange equipment at housing and communal services facilities. A new method of non-selective mechanical cleaning using a water hammer is proposed. The description and principle of operation of this cleaning system at the central heating station of the Ogarev Moscow State University are given. To confirm the effectiveness of the proposed technical solution, the results of thermal and hydraulic tests are presented.

Keywords: deposits, sludge, corrosion, cleaning, heat exchanger, water hammer, heat transfer

The article discusses the issues of modernization of the automated system for filling petroleum products (ASN). The complexity of maintenance of the automated control system due to the lack of up-to-date documentation and updated software, as well as periodic failures and high cost of spare parts became the main reasons for the implementation of modernization. Automatic control systems based on the law of proportional-integral-differential regulation have been developed: using a shut-off control valve with a positional actuator or a frequency converter to control the ACN. Mathematical models of the automatic control system have been developed in the MATLAB program using the Simulink library. An experimental model of a pumping station was assembled in laboratory conditions, and simulation modeling of the operation of an automated control system for a discharge and filling station was carried out. According to the results of experimental studies on the direct characteristics of assessing the quality of the transient process, the graph of a circuit with a frequency converter demonstrates the best results.

Keywords: automated pumping station, petroleum products, mathematical models, PID controller

The article discusses the use of a recurrent neural network in the problem of forecasting pollutants in the air based on actual data in the form of a time series. A description of the network architecture, the training method used, and the method for generating training and testing data is provided. During training, a data set consisting of 126 measurements of various components was used. As a result, the quality of the conclusions of the resulting model was assessed and the averaged coefficients of the MSE metric were calculated.

Keywords: air pollution, forecasting, neural networks, machine learning, recurrent network, time series analysis

The construction industry is undergoing regular changes these days, influenced by many different factors. Large and structurally complex construction projects reveal more and more imperfections in traditional construction methods, e.g. increased time or production costs, downtime, delays, etc. Lean construction and its principles have emerged in search of solutions to problems in construction. In the search for solutions to problems in construction, the term - lean construction and its principles appeared, which replaced traditional methods and aimed at finding new approaches in the implementation of construction activities. In this scientific article the definition of Lean Construction is given, and also the history of Lean Construction and its chronology are considered. The comparison of the traditional construction model and Lean model is given, and also the connection of Building Information Modeling (BIM) with Lean Construction principles is analysed and an example of this connection is given.

Keywords: lean manufacturing, lean construction, construction, lean construction principles, lean technology, lean model, lean philosophy, life cycle of an object, information modelling technologies, engineering

The article presents a way to increase the load-bearing capacity of a reinforced concrete column due to metal clips from the corners with an increase in the load on it. To ensure the joint operation of the existing column and the metal cage, the corners are subjected to prestressing, which is achieved by compressing the corners with jacks.

Keywords: reinforced concrete column, column reinforcement, metal cage, prestressing of the cage

The practical significance associated with the development of automated software systems for calculating joints of steel structures of buildings and structures is noted. Using the IDEA Statica software package as an example, the calculation and analysis of the operation of a steel unit connecting the lower chord of a truss to a column was carried out. The order and sequence of entering the initial data for calculating the connection is shown. The calculation results present in tabular and graphical forms the equivalent stresses and plastic deformations of the main elements, as well as the results of inspections of bolted and welded connections of these elements to each other. A comparative analysis of numerical and analytical calculations was performed. Conclusions are formulated based on the results presented in the article.

Keywords: calculation model, connections, steel structures, component finite element method, design, nonlinear analysis, work analysis, stress, plastic deformation, bolted connection, welded connection