The analysis of the foundations of modern cryptographic systems is carried out. Problems of classical cryptography arising in the development of quantum computers are considered. Considered are cryptographic protocols of quantum key distribution, their advantages and disadvantages. The analysis of stands for simulation of quantum key distribution available on the market is carried out. The rationale for the need to develop a training system has been made. The authors have developed a system for modeling and demonstrating quantum cryptographic protocols BB84, B92 and BB84 (4 + 2), intended for a detailed study of the principles of quantum cryptographic protocols in dynamics. The system provides the process of work both in text and graphic form. The developed system fully meets the needs of teaching students modern quantum information security technologies.

Keywords: information security; encryption; quantum cryptography; modeling; education system

Insulating materials are widely used in the petrochemical, energy and other industries. Thermal insulation materials play an important role in the energy saving of district heating systems and in the construction sector. In this work, the influence of the wetting and drying cycle on the thermal conductivity and density of the heat-insulating material is determined by the experimental method. The thermal conductivity of the insulating material was determined by the protected hot plate method. It has been established that after four cycles of wetting and drying, the thermal conductivity and density of the heat-insulating material increase up to 2 and 2.5 times, respectively.

Keywords: thermal conductivity of heat-insulating materials, density of heat-insulating materials, dampening of heat-insulating materials

The species diversity was studied and the ecological state of the tree and shrub vegetation on the territory of one of the oldest and largest parks in Rostov-on-Don - Maxim Gorky Park of Culture and Recreation was assessed. An area of 33,000 m2, located in the north-eastern part of the park, was allocated for study. 17 species of woody and shrubby plants were identified in the study area, among which the park-forming species are European linden (Tiliaeuropaea), Evergreen cypress (Cupressussempervirens L.), Common pine (the vital state of plants,the nature of the herbage closability, woody and shrubby plants, grassy lawn covering, urban park landscapes, the Park of Culture and Recreation named after Maxim Gorkiyabsence of signs of weakening (55%), and dead wood is only 1%. The quality of the lawn covering is quite low, and the soil under it is characterized by high compaction. Basically, the nature of the closure of the herbage is mosaic–group, and the projective coverage reaches maximum values (80%) for the entire study area in the early spring. Measures to preserve and optimize the park area are proposed.

Keywords: the vital state of plants,the nature of the herbage closability, woody and shrubby plants, grassy lawn covering, urban park landscapes, the Park of Culture and Recreation named after Maxim Gorkiy

In the article, it is proposed to take the density of soil particles as the maximum density, the determination of which does not require sophisticated equipment, is determined in the laboratory using a pycnometer, while the density of soil particles is a fairly stable value, depending only on the composition of the soil. As a result, a more advanced method has been developed for assessing the degree of compaction of sandy soils by using the density of soil particles and statistical dependencies as the maximum soil density without directly determining the maximum density and optimal soil moisture in the laboratory according to GOST 22733-2016. Based on the research of BeldorNIA, it is proposed to take the density of soil particles as the maximum density, the determination of which does not require the presence of complex equipment.

Keywords: highway, soil, soil compaction, soil composition, road surface, road defects, trackage, road construction, method, pycnometer

The analysis of accidents on the main gas pipelines was carried out. The mathematical dependences of the volume of gas located in a gas pipeline of various diameters are determined. A nomogram is proposed to determine the volume of natural gas located in certain sections of the gas distribution network.

Keywords: gas pipelines, accident rate, degassing, gas bleeding. gas compressibility factor

As part of Sol-Iletsky Mine No. 2, it is planned to erect and set up a health resort center for the treatment of respiratory diseases. This health center will provide medical services in the therapeutic salt chambers on the first horizon (123 meters underground). For this purpose, it is necessary to use the waste horizons of rock salt (chamber workings). For the construction of the health-improving complex for safety reasons in part of underground workings, it is required to arrange a fortification. This article deals with mathematical modeling and selection of the optimal type of support for chamber workings.

Keywords: mathematical modeling, stress-strain state, SSS, rock salt, roof support, chamber workings, finite element method, FEM, redevelopment

A set of data on potentially dangerous asteroids for the Earth is analyzed. According to descriptive statistics, a preliminary analysis and data processing is performed. The correlation between the parameters allows you to identify those that will be used to train the models. With the help of machine learning models, asteroids from the database are classified into hazardous and non-hazardous. Methods of logistic regression, k-nearest neighbors; decision tree and others are used. Using cross-validation, the best method is found, then its optimal hyperparameters are determined. The quality of the classifier model is evaluated by the metrics of completeness (Recall) and its standard deviation, as well as using the error matrix (confusion matrix) and the average absolute error in percent (MAPE). The results of analysis and modeling in Python are presented, demonstrating the high accuracy of predicting the resulting model.

Keywords: machine learning, predictive model, data analysis, imbalanced data, logistic regression, k-nearest neighbors, decision tree, random forest, support vector machine, cross-validation

The article presents the experience of automating the process of secondary sludge preparation in autoclave aerated concrete technology. It is proposed to use a non-cut non-isotope density meter of domestic production as a recording sensor. The algorithm of the system operation and the scheme of the technological process fragment are presented.

Keywords: automation, control system, production process, autoclave aerated concrete, secondary sludge, algorithm, density meter, quality of the finished product, sludge pool, density

Liquid pumping processes which require flow variations over a wide range are often equipped with centrifugal pumps connected in parallel. In such pumping systems, speed control enables the required capacity to be achieved with different numbers of pump units running and the selected speed values. The information required for modeling such systems, such as wastewater treatment and various cooling and water supply tasks, can be scarce, and the lack of real-time monitoring of operating points often sets limitations for precise optimization of energy efficiency. Consequently, easily implementable control strategies that can be adopted with minimal system data are needed, requiring adaptive methods. A significant part of pumping stations operate in conditions when the flow rate and the required pressure vary widely, which can lead to a decrease in the efficiency of their management and, as a consequence, a decrease in energy efficiency. Therefore, it should be noted that the task of choosing the optimal strategy for controlling pumping units during their parallel operation is very relevant.

Keywords: pumping units, energy efficiency, modeling, rotation speed, speed control

CFD modeling seems to be one of the most accessible and accurate ways to calculate the characteristics of flow processes using computational and physical-mathematical methods in solving practical problems today. In particular, it is used to determine the parameters of the indoor microclimate. This article describes the process of modeling the operation of hydraulic heated towel rails in the bathroom of a residential building and selects the optimal configuration based on the data obtained as a result of the calculation in the STAR CCM + software package.

Keywords: CFD modeling, building hot water supply, heated towel rail, heat flow, heat transfer, heat transfer, indoor climate, thermal analysis, SolidWorks, STAR CCM+

The tasks of preparing for the modernization of the automatic pressure control system with the transition from the use of a PD controller in favor of a PID controller and the introduction of a controlled electric fan drive in a boiler plant are being solved. A technique for constructing a fan model in the automatic control system for air supply to the boiler is given using the example of a VD-18 blower fan and a BKZ-160 boiler. The block diagram of the operation of the fan and pipeline is given. A mathematical model of the fan is shown, a calculation is made and a computer model is designed in MATLAB Simulink. The simulation results are presented, which prove the correctness of the obtained model. The presented model can serve as a basis for automating the air supply system in other boilers using blowers.

Keywords: automatic pressure control system, automatic control system, dynamic model, computer model, blower fan, boiler plant

The work is devoted to the glaciers of the North Caucasus. The factors influencing the dynamics of the glacier area are analyzed, and the principles of the organization of observations of glacier fluctuations are considered. The level of modern development of the field of remote sensing provides an excellent opportunity for a detailed and accurate study of the dynamic characteristics of the surface layer of ice on glaciers based on cartographic animations of a number of images. The work is based on data from space monitoring using the Meteor-M No. 2 apparatus.

Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

The problem of human self-knowledge is very relevant nowadays. People are constantly looking for new methods to study their own “I”. Graphology is one of such methods. The main difficulty of graphological analysis is the lack of automation of the process, the result depends only on the knowledge of the person. In addition, at the moment there is no service capable of carrying out a competent analysis of a person's handwriting. However, there are computer vision methods that, in combination, can produce work similar to that of a graphologist. Such methods include segmentation, binarization, and integral estimation methods. To compare the characteristics of handwriting with human characteristics of character, it is necessary to use classifiers. The use of all methods makes it possible to create a service that automates graphological analysis.

Keywords: graphology, handwriting, personal characteristics, graphological analysis, slope, direction of handwriting, text

In a market economy, it is required to calculate foundations using methods that will satisfy the requirements of the first and second limit states with the smallest margins, in order to save money. In this study, the analysis of sediments obtained by numerical and analytical methods was carried out. Analytical calculation is presented by the method of corner points according to the model in the form of a linearly deformable half-space and by the method of layer-by-layer summation presented in the form of modified Pasternak, Winkler-Fuss, Pasternak models. The numerical method is presented by the finite element method implemented in the software systems of the PC «Lira-SAPR» and the PC «PLAXIS 3D». As a result, it was found that the minimum discrepancy between the absolute settlement according to the corner point method in comparison with the analytical method according to the Winkler-Fuss, Pasternak, modified Pasternak models is 9.04%, 9.04%, 53.38%, respectively, and in comparison with the numerical method implemented in the PC «Lira-SAPR» and PC «PLAXIS 3D» is 10.49% and 0.52%, respectively. The highest accuracy in comparison with the method of corner points was shown by analytical calculations by the method of layer-by-layer summation in the formulation of Winkler-Fuss and Pasternak, and by the numerical method of calculation performed by the PC "PLAXIS 3D".

Keywords: geotechnics, foundations, «Lira-SAPR», system «Soil», «PLAXIS 3D», foundation sediment, angular point method, slab foundation, mutual influence of foundations, numerical method, analytical method, finite element method

Relevance and goals. The article is devoted to the description of the results of the development process of the geoinformation web portal "Interactive map " Natural and cultural heritage of the Republic of Mordovia. We travel with the Russian Geographical Society"", which implements the functionality of access to a digital map with a layered systematized display of spatial data on objects of natural and cultural heritage of the region. Materials and methods. The implementation of the metageosystem concept in the development of tourism and recreational development projects is based on the broad involvement of paleogeographic, landscape, archaeological, historical, ethnographic, demographic, cultural, environmental and economic information in the research process. Results. During the development of the geoportal "Natural and cultural heritage of the Republic of Mordovia. Traveling with the Russian Geographical Society" solved the problem of creating a new subsystem for visualizing geospatial data for a digital map based on modern web technologies. Conclusions. The developed geoportal system solves the problem of managing the tourist and recreational development systems of the region by implementing the concept of forming an interactive spatial data management tool.

Keywords: geoportals, cultural landscape, spatial data infrastructure, management in organizational systems, spatial data, decision making

The wastewater generated by the pulp and paper industry contains diverse contaminants such as organic substances, fine suspended powders, and dissolved solids. Currently, integrated treatment technologies are employed, utilizing thin-layer settling tank modules to eliminate solid contaminants. This study presents the outcomes of a comparative analysis of the efficacy of a conventional thin-layer module with flat plates and a modified thin-layer module consisting of two levels of plates, positioned in opposing directions, facilitating the rotation of water flow within the module. Through computer simulation techniques, it is demonstrated that the modified module design can enhance the cleaning efficiency by 8-30% for wastewater flow velocities ranging from 0.0025 to 0.0125 m/s. Additionally, particle trajectories and velocity fields were obtained, which clearly illustrate the direction of the dictating flow and circulation zones within the structure.

Keywords: Wastewater, pulp and paper industry, thin-layer module, module with rotation of water flow, computer simulation of particle deposition.

The article contains an analysis of the shallow elastic spherical shell on a rectangular plan, reinforced with ribs along its contour, under the uniformly distributed load. The problem is solved numerically with the variational-difference method, considering the geometric nonlineaity and the shear deformations of the shell and the ribs. As a result, the dependencies of the critical load on the shell stiffness and the ribs stiffness are obtained.

Keywords: shallow spherical shell, ribbed shell, stability, bending stiffness, geometrical nonlinearity, variational-difference method, critical load

GRP horizontal tanks are used for wastewater treatment. This material can be used for 50 years or more, which exceeds the lifetime of reinforced concrete sewage treatment plants. However, when designing the products, it is necessary to determine whether the tank should be manufactured using the continuous winding method or the spiral-crossflow method. The main problem in selecting the manufacturing method is to determine the stability of the structure against vertical loads from the soil mass. The continuous winding method provides high circular stiffness, hence resistance to various influences, while the spiral cross winding method deteriorates circular stiffness and reduces the cost of the product. The article examines constructed GRP structures made using different methods and located at different depths. The tests are carried out to study the strength characteristics of the material on the basis of the Plant of composite materials, the ring stiffness and the modulus of elasticity are determined according to GOST R 54925-2012, to confirm the data obtained, a comprehensive calculation is performed in the Midas GTS NX software using a work model (structure + soil). The Mohr-Coulomb model was selected as a model to describe the soil, the material characteristics were set according to the data obtained from the tests. The results of surveys and calculations proved the inability to use GRP containers manufactured by the spiral cross-winding method because of low circular stiffness resulting in loss of load-bearing capacity of the structure and further ingress of soil inside the container.

Keywords: GRP gorizontal containers, continuous winding method, spiral cross winding method

The accuracy of the calculation and the required computer time significantly depend on the choice of the turbulence model. This paper analyzes three turbulence models SST, k-w SST, and RNG k-e EWT with enhancement wall treatment applied to an in-line tube bundle. The distribution of heat transfer over the beam depth is determined. Velocity profiles in cross sections along the depth of the tube bundle are obtained. As a result of numerical studies, it was shown that the agreement with the experimental data for the SST, k-w SST, and RNG k-e EWT models was 75, 32 and 10%, respectively.

Keywords: turbulence modeling, tube bundles, heat transfer, mathematical modeling

The article raises the issue of maintaining the stability of the power system, including maintaining the balance of electric power. The occurrence of power imbalance can be determined by a criterion such as frequency. The authors have proposed a method of maintaining frequency including maintaining power balance in the power system by changing voltage on electric energy consumers, a hypothesis has been set and a corresponding laboratory study has been carried out, as a result of which dependence of frequency change on voltage of some electric power receivers has been obtained. A device an automatic unloading regulation of voltage has been developed and described, which will make it possible to supplement the existing emergency control equipment.

Keywords: renewable energy sources, grid inverters, mode parameters, Clark conversions, Park conversions

In this paper, we investigated the effectiveness of an intelligent system for classifying radiographic images into three classes using transfer learning and fine-tuning methods. The convolutional neural network VGG16 structure was used to evaluate the effectiveness of predicting the presence of characteristic pathologies by the system. A catalog consisting of 4,228 chest X-ray images was used for training, verification of training and testing this neural network. A catalog was divided into three classes such as pneumonia, Covid-19 and in the absence of lung diseases. To provide modeling processes there were used deep learning libraries such as Keras and TensorFlow. In the course of the work, there were presented the results of the neural network accuracy of the classification of chest X-ray images by full-trained neural network model. We also demonstrated an increase in prediction accuracy by using transfer learning method, as well as with fine-tuning of the neural network structure. Based on the results of the work, the neural network has learned to recognize images with signs of pneumonia, Covid-19 and normal radiograph. In conclusion, the best accuracy index of 98.4 % was achieved by using the fine-tuning method for our convolutional neural network.

Keywords: chest X-ray, Covid-19, pneumonia, intelligent system, machine learning, deep learning, convolutional neural networks, transfer learning, fine-tuning of convolutional neural network