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  • Determination of the dependence of the concentration of fine dust PM2.5 and PM10 in the atmosphere of residential areas

    Within the framework of the urban environment, the laws of distribution of the concentration of fine dust PM2.5, PM10 along road sections have been obtained. These data are necessary to assess the probability of exceeding the maximum permissible concentrations and to improve monitoring and control systems for atmospheric air. The analysis of the key factors influencing the content of PM2.5 and PM10 particles in the air of the territories adjacent to the roads has been carried out. Regression equations for total dust, PM2.5 and PM10 dust were obtained, allowing us to conclude that the concentration of PM2.5 and PM10 depends on total dust. The analysis showed that the mass content of PM10 in total dust pollution ranges from 73 to 81%, and the concentration of fine dust PM2.5 varies within two narrow ranges of about 11.6 and about 7 microns. A study of the proportion of PM2.5 of the total concentration showed that it is on average about 20%.

    Keywords: dust, emissions, concentration, atmospheric air, roadway, climate, linear city, correlation coefficient, influencing factors

  • Analysis of ultrasonic impact on mixing solutions and the degree of hydrophobization of the solid phase in suspensions for construction purposes

    The analysis of ultrasonic effect on mixing solutions and hydrophobization of solid phase in suspensions for construction purposes is carried out. It is shown that ultrasonic treatment leads to an increase in the mass content of particles with a radius of 2-7 μm in the mixing solution, which contributes to an increase in the relative tensile strength of the samples obtained on its basis. Ultrasonic treatment of suspensions with the same relative degree of hydrophobization of the solid surface led to different contact angles of wetting of solid particles: Ө = 120, 450, 930, 69.40 for clay, cement and silica particles. Ultrasound leads to a significant decrease in the volume fraction of liquid in a three-phase foam stabilized by hydrophobized clay particles, compared to the syneresis process in a gravitational field.

    Keywords: three-phase foam, silica suspension, clay, ultrasound, mixing solution

  • Evaluation of strength characteristics of brick masonry using bending waves

    Based on the results of experimental studies of the propagation of bending waves, the ability of the developed technique to assess the strength of a brick treasure is considered. A comparative analysis of the strength of the masonry was carried out using different methods (L.I. Onishchik formula, Eurocode 6). According to the correlation dependencies between the velocity of propa-gation of elastic waves and the strength of masonry, the presented practical data made it possible to prospectively evaluate the method using bending waves in the survey of buildings and struc-tures.

    Keywords: experimental studies, brickwork, elastic waves, bending wave velocity, strength

  • Stress-strain state of a triangular membrane panel under the action of various types of lateral loads

    Анализируется методика определения напряженно-деформированного состояния металлических опор линий электропередач при технической экспертизе объектов электросетевого хозяйства. Даётся пример расчета с использованием автоматического программного комплекса ЛИРА. Определяется наиболее напряженные участки конструкций. Расчётным способом подтверждается гипотеза о том, что трехгранное поперечное сечение траверсы портальной промежуточной опоры ВЛ 500 кВ экономичнее (эффективней) чем четырехгранное (классическое) поперечное сечение.

    Keywords: building structures, metal structures, energy facilities, stress-strain state, technical expertise

  • Ways to improve the reliability of buildings when making organizational and technological decisions in conditions of uncertainty

    The article is devoted to the issue of making organizational and technological decisions when the stock of information for alternatives to choosing the required tasks is either very small, or they are changing drastically. Since it is not easy to make an organizational and technological business decision due to the fact that it is not clear what the result will be, it is proposed to use game theory in conditions of uncertainty. What kind of decision will be made and which of the available strategies the designer will adopt depends on what economic effect will be obtained as a result of the implementation of the organizational and technological solution being developed. Game theory is a special class of mathematical models for decision-making under specific conditions. By choosing solutions in the wake of uncertainty, game theory formalizes possible knowledge about the course of action of the participants in the game in certain conflict situations and allows you to mathematically substantiate knowledge about a rational course of action in certain conditions. When constructing construction projects in environmentally unfavorable conditions, the risk matrix is compared and the best option for the development of a construction project is determined.

    Keywords: construction and technical expertise, reliability, organizational and technological solutions, diagnostic methods, efficiency.

  • Multidisciplinary research

  • Application of machine learning methods to the recognition of cardiovascular diseases

    This work is devoted to the study of the possibility of determining heart diseases on the basis of 13 categorical and numerical signs. We present a detailed analysis of the dataset, including dividing the data into training and test samples, dividing features into numerical and categorical, applying 4 different classification algorithms, checking the quality of the model using two techniques – delayed sampling and cross-validation. To assess the quality of the model, we pay attention to the value of the recall metric and the error matrix built on the test dataset from the deferred sample or on each test fold when using cross-validation. The results of the study are important both for a deep understanding of the relationship between certain medical indicators and heart disease, and for the development of effective methods for predicting them in the presence of individual symptoms.

    Keywords: cardiovascular diseases, classification task, quality metrics, cross-validation, recall, machine learning, random forest

  • An approach to filling in gaps in data on the operation of a hydraulic unit

    The paper provides a brief overview of publications on the application of mathematical modeling methods in the study of the patterns of functioning of hydroelectric power plants (HPPs). In particular, the following are considered: mathematical models of the total minimum water consumption for a cascade hydropower system in China; a mathematical model of hydropower plants; a mathematical model of two small hydroelectric power plants operating in tandem; accurate modeling of hydraulic transient characteristics in a complex drainage system. The task of filling in the gaps in the data concerning the operation of hydroelectric power plants is formulated. The approach to its solution is proposed to be based on the use of the method described in previous publications by one of the authors and based on the use of regression analysis apparatus. The specific task of filling in data gaps for a hydroelectric unit of one of the Siberian hydroelectric power plants has been solved. The following factors are used: active and reactive power of the electric generator, voltage, current and temperature of the stator iron, rotor current, air cooler hot air temperature.

    Keywords: hydroelectric power plant, electric generator, data gaps, predictive analytics, regression model, adequacy criteria

  • Grain boundary mechanism of fatigue crack growth

    Overhead power line wires are affected by various external factors such as wind, ice deposits, variable temperature conditions, excessive humidity. This eventually leads to fatigue failure of the wire. It consists in the origin and slow growth of a fatigue crack. The final stage of destruction is the sudden movement of the crack at high speed. The paper proposes a model of slow crack growth, at the mouth of which there is a grain boundary. Under the influence of external stress, a section of the border is a source of vacancies. The resulting vacancy concentration gradient between the grain boundary and the free surface at the crack mouth leads to a diffusion flow of vacancies into the crack. From the solution of the diffusion problem, the magnitude of the flow and the rate of increase in the crack length are found.

    Keywords: crack, grain boundary, vacancy diffusion, fatigue failure, air line, mechanical stress, vacancy flow

  • Mathematical modelling of gantry pile foundations under seismic action

    Gantry piles have been developed to transfer a large load to the load-bearing foundation when erecting critical structures due to the larger contact area of the piles with the ground compared to vertical piles. The design of gantry pile foundations is the most labour-intensive. The responsibility of making a mistake increases when designing this foundation under seismic conditions. This paper deals with the modelling of the performance of cargo piles under seismic loading conditions in the construction of foundations for bridge piers. The results obtained are part of a larger scientific study on the feasibility of using gantry piles in high-rise construction in earthquakes of 6 to 10 on the Richter scale.

    Keywords: gantry piles, deep foundation, seismic effects, overpass, modelling, finite element method, soil mass, stresses, deformations, foundation-soil mass system

  • Reports on current research

  • Materials for 3d-printing: review of patents

    3d-printing is the leading direction in world advanced technologies. For today 2614 patents were displaying in the Worldwide date base. General Electric is more effective companies in patenting materials for 3d-printing.

    Keywords: materials for 3d-printing, review of patents

  • Hardware and software complex for controlling luminaires via the Dali protocol

    This article provides a description of the developed hardware and software complex for controlling lamps using the DALI protocol, design features and software code, recommendations for operation.and development of new production on available floor spaces. The most important organizational economic targets of a diversification of management are presented by innovative activity of the industrial enterprise.

    Keywords: DALI protocol, lighting device, lighting control, Arduino, luminous flux

  • Development and evaluation of the design of a mechanized parking system

    The article discusses the development and evaluation of the design of a rotary-type mechanized parking system, the use of which will solve the problem of shortage of parking spaces in large cities. The paper presents the results of the research, a patent analysis was carried out, the composition of the mechanized parking system was determined and a rotor-type design was developed, an engineering analysis of the design was performed using the Autodesk Inventor software system. The calculation showed that the structure meets the requirements for strength characteristics.

    Keywords: mechanized parking system, modeling, parking space, durability, static research

  • Application of dispersion analysis method to identify non-obvious dependencies between characteristics of titanium plate processing

    The article is dedicated to analyzing methods for processing experimental data in the field of improving manufacturing technologies, with a focus on the processing of titanium alloys. In the modern context of natural science experiments, characterized by large volumes of information, there is a need to apply mathematical methods and computational systems for effective data analysis. Research conducted at the Department of "High-Performance Processing Technologies" at MSTU "Stankin" aims to identify the optimal type of wear-resistant coating for cutting tools when processing titanium plates. Titanium, with its low thermal conductivity and high chemical reactivity, presents certain challenges during processing, necessitating a thorough investigation of the relationships between cutting conditions and process parameters. The article discusses existing problems related to the insufficient study of these relationships and proposes a solution for data storage and processing through the creation of a unified database. This will enhance the visualization and analysis of experimental results, thereby improving the efficiency of research and the quality of manufactured products. The results of this work may be beneficial for both scientific research and practical applications in industry.

    Keywords: technological process research, cutting tool, cutting mode characteristics, systems analysis

  • Automated control of skills in solving problems in fuzzy modeling based on a computer training complex

    The study is devoted to the development of models, algorithms and software for computer training complexes (CTC) for training developers of automated information systems (AIS). The process of automated control of students' knowledge and skills using CTC in studying the mathematical support of AIS (using fuzzy modeling as an example) is formalized based on IDEF0 diagrams, and the process of assessing exercise performance as one of the control components. The advantage of CTC is that the teacher does not need to develop individual exercise options, since CTC configures the structure and complexity of the exercise and then automatically generates a unique version of the exercise for each student undergoing knowledge testing on the topic being studied. The student's performance is checked automatically by comparing the mathematical models of the student's solution to the task and the reference solution generated in CTC based on the problem statement. Algorithms for assessing task performance in fuzzy modeling exercises have been developed. A prototype of CTC has been created in the form of a web system with personal accounts for the teacher and the student. The developed concept and algorithms for monitoring knowledge and skills in fuzzy modeling using the CTC can be adapted for various disciplines in the field of mathematical, software, information and other types of support for AIS.

    Keywords: automated information systems, mathematical support, fuzzy modeling, computer training complex, e-learning, distance learning

  • Methodological approach to solving the problem of finding bugs and undocumented features in software based on the class of path finding problems on graphs

    The paper methodologically shows the identity of the mathematical problem of graph path searching with the technical problem of searching for various defects in software, in particular, bugs and undocumented features. The graph model of software functioning, which became the basis for the presented methodology, is briefly described. New research directions based on graph theory problems, which have not been previously used to search for defects in software, are stated.

    Keywords: graph model, software, graph pathfinding, breadth-first search, meet-in-the-middle method, malicious software

  • Analysis and modeling of interrelations between indicators of losses, production and consumption of food products

    An analysis of the life cycle of food products, the relationships between indicators of production, consumption, food losses, as well as the quality of life of the population will allow us to form a number of measures to reduce food losses and food waste. The paper sets the tasks of identifying the sources of food losses based on a statistical study of the level of losses in the regions of the Russian Federation and an analysis of the life cycle of a food product. The analysis of indicators of production and product losses is carried out on the example of potatoes, vegetables, fruits, meat, milk, eggs. The correlation analysis of indicators of production, consumption of products, and food losses showed that the greatest losses occur at the stages of production, processing, and sale in retail chains. Clustering of the regions of the Russian Federation according to indicators of food losses has been performed. Clusters with high production, consumption, and loss rates and with low production, consumption, and loss rates were formed for each type of food under study. A model of the life cycle of food products in BPMN 2.0 notation is constructed. The stages of the life cycle characterized by food losses have been identified. General recommendations on food loss management have been formed.

    Keywords: food losses, food loss modeling, correlation analysis, cluster analysis, business process modeling

  • The concept of digitalization of the construction organization project

    The concept of digitalization of the construction organization project (POS) is presented, which is based on its close connection with the construction schedule. The place of the POS in the digital model of the building at the project stage (PIM) is considered. based on its digitalization, taking into account the relationship between information modeling at the project stage (PIM). The main problems that may arise when implementing the digital version of the POS in the general information model at the project stage are identified.

    Keywords: BIM, TIM, POS, digital model, calendar schedule, construction organization