Objective. The aim of the study is to identify the factors determining the strength of adhesive joints in composite materials containing sodium polysilicates.Method. The influence of sodium polysilicate synthesis methods on the adhesive properties of composite binders was analyzed. Traditional and innovative methods, including hydrothermal, autoclave, and sol-gel technologies, were considered. Particular attention was paid to the parameters of temperature, pressure, and reaction time. Sodium polysilicate was obtained outside the composite by reacting anhydrous sodium silicate with a silicon dioxide hydrosol solution at 70–90 °C and holding for up to 0.5 hours.Result. The influence of various methods for producing sodium polysilicates, as well as changes in the silicate modulus and binder concentration on the adhesive properties of the materials, was determined. The strength characteristics of the samples under various external influences were determined. It was found that the strength of the adhesive joint based on sodium polysilicates depends on their concentration and synthesis conditions. The optimal concentration of the polysilicate binder is 0.14-0.2 g/cm² for binders obtained in the composite, and 0.2-0.28 g/cm² for those synthesized separately. Experiments have shown that samples bonded with polysilicates synthesized separately from the composite mixture fail along the adhesive line.Conclusion. The obtained results can be used to develop new formulations and methods for improving the performance and durability of building materials. Future research plans to use sodium polysilicate with a modulus of no more than 10 to optimize properties and extend the service life of materials at high temperatures. A promising direction is the development of heat-resistant composites with a high silicate modulus and reduced Na2O content, which contributes to improved fire resistance and thermomechanical properties.
Objective. This article addresses the problem of automated detection of connections to wired communication lines, which is relevant in the context of increasing threats of hidden access.Method. The study is based on methods of detection, identification, classification of threats to information security of objects.Result. An extended classification of communication lines and connected devices is proposed, taking into account signal characteristics. The limitations of control methods, pulse reflectometry and frequency-parametric approaches are analyzed. A classifier structure has been developed that allows for the formation of reference signal profiles and the identification of deviations in real time. The approach improves the accuracy of remote identification, reduces the influence of the human factor, and creates the basis for intelligent monitoring systems. The robustness of the classification against environmental changes and interference is also discussed.Conclusion. The results may be applied in automated control of communication line integrity.
Objective. The aim of the study is to construct a matrix model for determining the level of cyber victimization.Method. The problem of quantitative assessment of cyber victimization based on the Cattell test is presented. An algorithm for converting the mathematical model for determining the degree of susceptibility to cybercrime into matrix form is provided.Result. The concept of a composite cybervictimization criterion is introduced. A mathematical model has been developed for identifying the level of propensity for cyber-victimization in both numerical and qualitative forms. Test modeling was conducted to verify the adequacy of the constructed models with different types of input data.Conclusion. The correctness of the matrix model was confirmed by the coincidence of the obtained results with the results of simulation conducted using the original model. The capabilities of the software application developed based on the considered models are described. Potential application areas for the software application and paths for its modernization are proposed.
Objective. The aim of the study is to develop an optimization network model for maximizing the volume of transmitted data while meeting the quality criteria for cloud resource management.Method. The study is based on classical graph theory (the Ford-Fulkerson algorithm) and multi-criteria optimization, supplemented by a logarithmic data normalization method.Result. The model presents an effective approach to optimizing data flow in a cloud environment, enabling the determination of the optimal data transfer route between network nodes, taking into account resource constraints and performance requirements. The principles and algorithm of the model are defined; examples of application in cloud resource management are given.Conclusion. The network model is an important tool for efficiently managing cloud resources, optimizing data flows and ensuring high application performance.
Objective. The aim of this study is to investigate the effect of two additives – the hardening accelerators «Fastkick 111» and «Centrament Rapid 151» on the strength properties of CSM.Method. To analyze the strength properties of crushed stone-gravel-sand mixtures using strength accelerators, cylindrical samples were developed and tested in accordance with the requirements of GOST R 70455-2022 "Crushed stone-gravel-sand mixtures treated with inorganic binders. General specifications".Result. A comprehensive study of the characteristics of CPCS samples depending on the dosage of cement and complex hardening accelerators made it possible to develop optimized formulations that ensure maximum material reliability. It has been experimentally established that increasing the cement content in the composition of mixtures leads to a proportional increase in strength indicators. Maximum strength is achieved by adding 4% cement and 2.5% Fastkick 111 to the mixture. At 5 days, the mixture reaches M60 strength, at 7 days – M70, and at 28 days – M80.Conclusion. The use of additives in strengthening crushed stone-sand mixtures increases the tensile strength of samples, demonstrating improved crack resistance. The "Fastkick 111" additive accelerates the process of laying the top layers of the pavement, reducing the waiting time to three days after compaction; it also helps reduce cement consumption by 20% without compromising strength properties.
Objective. The aim of the work is to develop a mathematical model of a microservice system to optimize the configuration of this system.Method. Methods of graph theory, probability theory, and decision theory were used for modeling, namely probabilistic graphical models such as Bayesian networks that combine elements of all these theories.Result. A mathematical model of a microservice system based on a Bayesian network is described. A modified inference algorithm for this network and a configuration optimization algorithm taking cascades into account are proposed. The time complexity of inferring the optimal configuration is estimated. An experiment applying the proposed algorithms to a model system of 15 microservices was conducted, demonstrating that the configuration selected using the proposed model and algorithms has the lowest percentage of time the microservice system was in a state of service level agreement violation.Conclusion. The model and algorithms will help in selecting the optimal configuration by taking into account cascading effects, discrete and continuous parameters. Further conclusions should be drawn by integrating the model with existing orchestration systems.
Objective. The purpose of the research is to develop a methodology and algorithms for scenario-oriented processing of typical engineering situations for digital support of construction works aimed at bridging information gaps and improving the efficiency of the production and technical department.Method. The research is based on a scenario-oriented approach implemented as an integrated add-on to common CAD systems (using AutoCAD as an example) at the level of event-driven application logic. The methodology includes a formal model S = ⟨I, P, D, A⟩ and a three-level semantic structure used to describe and structure the transformation of geometric drawing objects into logical information carriers.Result. A software add-in has been developed and tested on real construction projects, which made it possible to systematize executive documentation workflows. The implementation of the system demonstrated a reduction in cognitive load on engineers, automatic detection of typical inconsistencies and duplication patterns, as well as improved accuracy and traceability of data through visual representation of work statuses directly on CAD drawings.Conclusion. The study demonstrates that the transition from linear document management to a scenario-oriented, event-driven application logic architecture, integrated into familiar CAD systems, makes it possible to effectively manage incomplete information, minimize human factor risks, and create a foundation for further development of formal scenariobased automation in construction production support.
Objective. The aim of the study is to theoretically substantiate, develop and experimentally validate a model for assessing the engineering maturity of a student project, integrating performance measurement, system modeling and justified improvement of the solution.Method. Theoretical analysis of pedagogical and engineering approaches; modeling of the engineering maturity index; quasi-experiment with paired comparison; statistical analysis (Wilcoxon test, Cliff's delta); instrument validation through expert assessment.Result. Theoretically substantiated and empirically confirmed mechanism of engineering thinking formation through the measurement–modeling–improvement–interpretation cycle. Developed project engineering maturity index (Cronbach's α = 0.87, inter-rater reliability r = 0.82). On a sample of 40 students (two cohorts): the proportion of projects with measurable improvement ≥20% increased from 23% (95% CI: 10.0–36.0) to 71% (95% CI: 56.9–85.1) (p < 0.001, Cohen's d = 1.34), the mean engineering score — from 61±12 (95% CI: 57.2–64.8) to 84±9 (95% CI: 81.2–86.8) (p < 0.001, d = 1.12), and artifact completeness — from 12% (95% CI: 1.9–22.1) to 89% (95% CI: 79.3–98.7) (p < 0.001, d = 2.15). Predictors of success identified: test protocol completeness (β = 0.42, p < 0.01) and bottleneck model quality (β = 0.38, p < 0.05).Conclusion. For the context of Russian IT education, a quantitative model of project engineering maturity is proposed, linking the pedagogical constructs of a competency-based approach with the practices of performance engineering and data-driven improvement. Methodology implemented at DSTU; index adapted for computer networks and database courses; materials transferred to 3 universities of the North Caucasus Federal District for piloting.
Objective. The aim of this study is to develop a cooling thermoelectric device (CTED) for the treatment of radiation-induced oropharyngeal syndrome through local hypothermia.Method. The study is based on thermodynamic analysis, in-kind modeling, and computational modeling of cryogenic equipment to ensure the reliability, environmental friendliness, quiet operation, functionality, and compactness of the CTED.Result. The CTED was developed, which, in addition to a cold source in the form of standard thermoelectric modules (TEMs), includes a mouthpiece, a transport system, and a system for removing heat from the hot junctions of the TEMs. Based on calculations in the software package, the type of TEM used in the CTED was determined. Dependencies describing the main characteristics of the CTED and the TEMs comprising it were obtained. The following graphs were plotted: the change in the refrigeration capacity of the thermoelectric module, the coefficient of performance, and the supply voltage as a function of the temperature difference between the junctions of the thermocouples for various values of the supply current; the dependence of the voltage on the thermoelectric module on the supply current for various values of the temperature difference between the junctions of the thermocouples; and the dependence of the coefficient of performance of the thermoelectric module on the supply current. The graphs are presented at a temperature of 47°C at the hot junctions of the thermocouples included in the thermoelectric module.Conclusion. The following parameters of the thermoelectric module were determined: the number of DRIFT-1.2 thermoelectric modules is 2 pcs., the operating range of the refrigeration capacity of a single thermoelectric module is from 37 to 70 W with an average temperature difference between the junctions of 35 K, the supply current is from 4.8 to 8.2 A with a power consumption of 90 to 300 W, the coefficient of performance is from 0.2 to 0.6.
Objective. Building a reliable security system for the automated systems of the internal affairs agencies of the Russian Federation requires a rational allocation of resources. This paper examines an approach to determining priorities in the implementation of protective measures.Method. This study is based on an analysis of data from the FSTEC of Russia's threat database, as well as a review of scientific publications, specialized literature, and online sources.Result. A proposed approach to allocating security resources for automated systems of the Russian Federation's internal affairs agencies (hereinafter referred to as the RF IAS) is presented, and possible protective measures are discussed. An approach to allocating security resources for the RF IAS is presented, along with possible protective measures.Conclusion. The need for a comprehensive approach to ensuring the protection of the RF IAS is emphasized, utilizing both software and hardware protection.
Objective. The objective of the study is to create a decision support system (DSS) that automatically analyzes sensor data, processes statistical data, and alerts the operator to the need for PLC programming, providing calculation results on the predicted technical and economic effect using an artificial neural network.Method. The study is based on methods for constructing intelligent control systems for technological processes and production.Result. The study examined the possibilities of increasing the efficiency of the automated process control system by improving the accuracy of the IHP controller settings. A method for improving the accuracy of the automated process control system by using an artificial neural network is considered. It is proposed to perform forecast calculations based on hydrometeorological center forecasts with a forecast period of 4-6 hours ahead. A set of additional sensors necessary for improving the forecast accuracy is proposed. The additional capital expenditures will pay for themselves within 2 heating periods.Conclusion. Existing approaches to the digitalization of heat power equipment control methods are considered. The use of an artificial neural network allows for increasing the accuracy of the IHP controller settings.
Objective. The article presents the results of studies of the burning breed of the mine dumps of the Abashevsky coal deposit of Kuzbass, and the possibility of using in construction technologies to solve the environmental problem related to the need to dispose of it.Method. The study is based on an effective method for processing mineral by-products for subsequent use in the production of building materials: mechanical activation, which unlocks the raw material potential of the secondary mineral product by altering its morphology and structure. The development of specific surface area and structural defects in the material, caused by increased energy during grinding, alters its physical, chemical, and technological properties.Result. Combined mechanical activity of burning breed, together with slag waste of steeling production, helps to engage the silicate component of activated products in the structural formation of the astringent system.Conclusion. The organization of the production of building mixtures of various functional purposes using burned breeds will help to solve the environmental problem to dispose of these large-capacity waste from coal mining and ensure the economic, environmental and social significance of the most important fossil raw materials of the coal regions of Russia.
Objective. The article discusses the problem of quantifying the level of security of automated systems of internal affairs bodies (AS) in the context of a constant increase in the number of identified vulnerabilities and limited resources spent on their elimination. An analysis of approaches to assessing the security of information systems is conducted, and their limitations associated with the lack of a formalized accounting of resource constraints and relationships between vulnerabilities are shown.Method. A mathematical apparatus based on a set of optimization models is proposed. Three tasks are considered: minimizing the likelihood of exploiting system vulnerabilities by selecting the optimal elements of the AS control system; selecting the most vulnerable elements for priority verification; selecting a set of vulnerability mitigation tools, taking into account their cost and error tolerance. Dynamic programming and optimization methods were applied.Result. The results of the computational experiment on model data demonstrate the effectiveness of the proposed approach, which makes it possible to move from "greedy" algorithms for eliminating vulnerabilities to optimal security strategies. Joint solution of optimization problems ensures rational allocation of resources and reduction of the probability of vulnerabilities under time and cost constraints.Conclusion. The developed method and models can be used as a basis for practical mechanisms for managing the security of ATS automated systems. The application of the proposed approach opens up the prospect of integrating quantitative methods into the assessment processes and increasing the level of security of automated law enforcement systems.
Objective. The aim of this study is to create an effective model of the dynamics of a dual-axis unmanned vehicle, suitable for developing autonomous control algorithms.Method. The study is based on mathematical modeling methods.Result. This paper presents a mathematical model describing the dynamics of an unmanned vehicle with two steering axes. It considers the dynamics of the center of mass, suspension dynamics, body rotation around the center of mass at pitch and roll angles, the effect of wheel lift-off due to suspension deformation and changes in vertical loads, and the force of gravity during longitudinal movement when the body is tilted. An analytical method for calculating the moments of inertia about the main axes is proposed, based on the geometric parameters and position of the body, wheels, and the center of mass of the load. To simplify the modeling, the following assumptions were made: wheel rotational dynamics are not considered, tire-road interaction is described in a simplified manner, and the dynamics of the power and steering gears approximated by first order differential equations.Conclusion. The input and output of the proposed mathematical model correspond to real signals from the onboard control system, ensuring its applicability for debugging control algorithms under conditions close to operational ones. The simulation results demonstrated the correctness of the described relationships for modeling unmanned vehicle dynamics and their applicability for debugging motion control systems.
Objective. The purpose of this study is to improve the security of a situation center, which is part of critical information infrastructure.Method. The research methods used in writing this paper include systematization, analysis, and description.Result. A situation center model has been defined, and a threat model has been developed. Four approaches to determining the importance of protection against various types of cyberattacks are proposed, and recommendations for protection are developed.Conclusion. The results obtained in the work not only structure information on issues of ensuring information security of the situation center, but also attempt to mathematically describe the patterns of its modernization, which can become the basis for further research, both in the direction of the study and in related fields.
Objective. The aim of the study is to develop an algorithmic method for identifying the parameters of a homogeneous nested piecewise linear regression of the second type with the second order of nesting using the least absolute values method.Method. Estimating unknown parameters is accomplished using a linear-Boolean programming problem. Its solution presents no computational difficulties due to the availability of a significant number of effective software tools.Result. The solution of the formed linear-Boolean programming problem allows us to calculate estimates of the model parameters, and the analysis of the optimal values of the Boolean components - to determine the nature of the response of the external and internal maxima of both levels in it.Conclusion. The results indicate the effectiveness of the proposed method for calculating the parameter estimates of a homogeneous nested piecewise linear regression of the second type with the second order of nesting using the least absolute values method.
Objective. The paper considers the solution of the heat transfer problem for flow turbulators with a semicircular cross-section using multiblock computational technologies based on the solution of Reynolds' equations (closed for the transient regime using Menter's shear stress transport model) and the energy equation (on intersecting structured grids of different scales) by the factorized finite volume method (FVM).Method. The paper uses computational methods to mathematically model heat transfer in pipes with turbulators for viscous coolants at very high (up to a billion) Reynolds criteria, characteristic of developed turbulent flow regimes.Result. The calculations were performed using a theoretical method based on the solution of Reynolds' equations by the factorized finite volume method, closed for transient regimes using Menter's shear stress transport model, and the energy equation on intersecting structured grids of different scales (FVM). Using the FKOM method, both local and average flow and heat transfer characteristics were obtained in pipes with turbulators for a viscous coolant for a developed coolant flow regime. This allowed us to determine heat transfer intensification levels for these regimes.Conclusion. Heat transfer intensification in air is postulated for high millionth O. Reynolds criteria, which is potentially relevant for channel flows in heat exchanger channels, with noticeable increases in hydraulic resistance and can increase relative to reduced O. Reynolds criteria for large relative protrusions d/D = 0.90. It was formulated that for billionth O. Reynolds criteria, channels with protrusions are inferior to channels with roughness in terms of heat transfer intensification, since there is a lower level of heat transfer intensification with approximately the same increase in relative hydraulic resistance.
Objective. The aim of the study is to substantiate the possibility of applying A. Renyi's entropy to the problem of analyzing additive and multiplicative growth processes related to complex technical systems.Method. The Renyi model is proposed, which includes a generalization of the properties inherent in the elements of a complex system and is necessary for the analysis of growth processes. The model includes mathematical expressions for calculating the probabilities of additive and multiplicative growth processes, as well as a generalized equation in a universal form that links both types of growth.Result. The analysis shows the importance of the obtained values of Renyi entropy depending on the parameter a of the model associated with the growth processes. The performed calculations of the Regnal entropy showed that changing the parameter a makes it possible to expand the range of applied uniformity measures. If the parameter value is assumed to be close to one, therefore, sensitive processes are considered, characterized by subtle differences in the probability distributions of the states of objects. By increasing a, the sensitivity of the estimate decreases, making it possible to identify the largest deviations in the probability distribution. Variation of parameter a is possible provided that different sensitivity levels are selected and is an integral part of changing the structure of the studied set of objects.Conclusion. The applicability of Shannon entropy is limited to additive processes; Renyi entropy is applicable to the study of complex systems and processes. It is an effective tool for analyzing growth processes, endowed with flexibility in applying sensitivity characteristics in assessing growth changes. By changing the parameter a, it is possible to estimate the heterogeneity of the probability distribution on a set of states of objects with different levels of detail. In particular, the use of The use of Renyi entropy is effective for analyzing the state of technical, economic, and biological systems.
Objective. Research and analysis of parameters of the stress-strain state of reinforced concrete beams using periodic ultrasonic testing in compressed and tensile zones and development of proposals for the application of the method in the inspection and monitoring of reinforced concrete structures in operation.Method. Experimental studies were carried out using a four-point bending scheme in accordance with GOST 8829-2018 with measurements of deflections in the span center and at the points of load application and concrete deformations on a 500 mm base at the level of compressed and tensile reinforcement with calculation of curvature, recording the appearance and development of cracks and changes in the ultrasonic pulse velocity in the pure bending zone in the compressed and tensile zones of the section and calculating the length of normal cracks.The length of normal cracks was also calculated. Beams made of concrete with classes B25 and B40, with reinforcement coefficients of 0.0149 and 0.0111, were studied.Result. The relationships between the relative ultrasonic pulse velocity, the change in the relative normal crack length, the section stiffness, the elastic modulus, the relative height of the unbroken concrete section, and the deflections along the beam length at load application points and at midspan were determined. A gradual change in the ultrasonic pulse velocity was determined. In beams with a shear force failure pattern, no increase in the ultrasonic pulse velocity was detected in the tension zone.Conclusion. The proposed method for analyzing the stress-strain state using discrete measurement of the velocity of an ultrasonic pulse in compressed and stretched zones of reinforced concrete beams can be used in experimental studies and in the inspection and monitoring of operated reinforced concrete structures.
Objective. The aim of the research is to build a mathematical model for solving the problem of optimizing the flight path of an aircraft to collect information about the technical condition of buildings and structures at hazardous production facilities. To solve this problem, it is necessary to determine the constraints affecting the flight and consider the problem under four conditions: ideal flight conditions; flight conditions under the influence of weather factors; flight conditions in the presence of a physical obstacle in the research area; and the condition of being affected by weather factors and the presence of a physical obstacle in the research area. An efficiency criterion is also introduced.Method. A modified traveling salesman problem algorithm is applied as the basis for finding the optimal flight trajectory, and the time for acceleration, deceleration, and hovering of the aircraft is also taken into account.Result. A mathematical model for optimizing the flight trajectory of an unmanned aerial vehicle during the frontal inspection of buildings and structures has been proposed, taking into account both ideal and non-ideal flight conditions.Conclusion. The result of the conducted research is a formal representation of the problem of constructing an optimal flight trajectory for an unmanned aircraft.
