Founded in: 1993 Field of science and issues in focus: Journal reflects the problems of the development of theory, design practices and technologies of aviation-space technology; control systems; electronic systems; computer systems and information technologies in the management of enterprises, programs and projects. The edition is included in the List of Scientific Professional Publications of Ukraine (Category "Б") by the Ministry of Education and Science of Ukraine № 975 of 11.07.2019. Specialties (ISCED-F 2013): 0413(073, 275) Management and administration 0541 (113) Mathematics 0612 (126) Database and network design and administration 0613 (121, 122) Software and applications development and analysis 0688(124) Inter-disciplinary programmes and qualifications involving Information and Communication Technologies 0713 (141, 142) Electricity and energy 0714 (173, 174, 175, 176) Electronics and automation 0715 (131, 142) Mechanics and metal trades 0716 (134, 142, 173) Motor vehicles, ships and aircraft 0788 (132) Inter-disciplinary programmes and qualifications involving engineering, manufacturing and construction 1041 (272) Air Transport ISSN: 1727-7337 (Print), 2663-2217 (Online) Media identifier No. R30-01717 (Decision dated 10/26/2023 No. 1146). Indexing: Vernadsky National Library of Ukraine; NRAT; Ulrichsweb Global Serials Directory; OCLC WorldCat; DOAJ; Index Copernicus; CiteFactor; AcademicKeys; Infobase Index; WorldCat; Google Scholar; Scillit; OUCI; Sherpa Issues and articles from 2017 have a DOI from CrossRef Founder: National Aerospace University «Kharkiv Aviation Institute» Periodicity: 6 issues per year (+ special issues). Editor-in-Chief: Yepifanov Sergiy Executive secretary: Leshchenko Oleksandr Editorial office address: 61070, Kharkiv, 17 V. Manka Str., chair 302. Tel.: +38(057)7884381, +38(067)1205222 E-mail: ntrio@khai.edu Archives of issues are HERE & HERE This journal provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Національний аерокосмічний університет "Харківський авіаційний інститут"
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Noise of elastic thickness vibrations of a helicopter blade induced by aerodynamic loads
This study develops a theoretical model of vibration-induced noise generation in helicopter blade elastic vibrations. Vibration and aerodynamic noises are generated during helicopter rotor rotation. Numerous studies have been conducted on aerodynamic noise, and a number of theories have been proposed. However, vibration noise has been mainly studied experimentally or modeled only by the ordinary mechanical vibrations of the blade as a single body—a beam or plate. This does not consider the blade’s elastic deformations, which generate elastic sound waves inside the body. Until now, no model has mathematically described the transformation of elastic longitudinal and transverse waves arising inside an elastic blade into sound waves. These waves emerge from the blade and propagate into the air during elastic thickness vibrations, which are formed by variable deformations under the action of variable blade loads. The research methods are based on the analytical solution of the boundary value problem for the Navier-Cauchy equation, which is divided into four Helmholtz equations: one for the scalar potential and three for the vector potential. Elastic waves of the Love's wave type are studied, but for a finite-sized thin elastic plate. Limiting standing waves to only one direction is impossible for a helicopter rotor blade of finite sizes, since the blade has finite dimensions. Therefore, the following model of vibration noise generation was proposed: the blade is approximately replaced by a thin elastic plate, inside which elastic longitudinal and transverse waves arise, which are governed by Helmholtz equations. The general solution to these equations is found using the method of variable separation (Fourier method). The reflection and scattering issues of sound waves from the interface between an elastic body and air are not considered in this study. Results and conclusions. This paper proposes a new physical model of vibration-induced sound: vibration-induced sound is generated as a result of the emission of elastic longitudinal waves, which are emitted from inside an elastic blade outward into the air. An analytical solution of scalar and vector potentials in the form of standing sound waves was obtained for a boundary value problem with a known distribution of aerodynamic, time-harmonic loads on the blade surfaces. This solution allowed us to write expressions for normal stresses on the blade surface. Time-varying stresses transfer the energy of longitudinal standing sound waves, which emanate from the blade’s center outward into the air. They are the source of vibration-induced noise. The expression for normal stresses on the blade surface contains derivatives of both scalar and vector potentials, i.e., it considers the influence of both longitudinal and transverse waves. Thus, both wave types implicitly participate in the formation of normal stresses on the blade surface. The periodic change in these stresses over time causes periodic blade thickness deformation, which is the source of air acoustic vibrations. The calculated data for the longitudinal wave potential on the blade surface coincide with the well-known Gutin’s theory of rotational sound: the maximum generated sound wave is located near the blade’s outer end. This indicates that the analytical solution obtained in this work physically describes the vibration-induced noise generation process.
Copyright (c) 2025 Petro Lukianov, Sergii Karmazin
Development and validation of a CFD model prediction of temperature separation in swirling fluid flows
In this study, a numerical model was developed for performing 3D computational fluid dynamics (CFD) simulations of the total temperature separation phenomenon in rotating flows, and the accuracy of this model was validated. This study aims to confirm that the CFD simulation results accurately reflect the physical processes occurring in a real swirling fluid flow. This study examines a rotating fluid flow in a counterflow Ranque-Hilsch vortex tube. The commercial three-dimensional CFD solver Ansys CFX 2024 R2 is used for calculations in a steady-state formulation. To determine the required mesh resolution, a grid convergence study was conducted using the Grid Convergence Index (GCI). The obtained indicators meet the GCI requirements in detailed studies with low error margins (GCI ≤ 5%). The selected mesh for further calculations comprises 13 million elements. This study includes simulations of the vortex tube at various cold stream mass fractions and with different turbulence models. Specifically, the standard k-ε model, the Shear Stress Transport (SST) model, and two Reynolds Stress Models were considered: the Baseline Reynolds Stress Model (BSL RSM) and the Speziale-Sarkar-Gatski Reynolds Stress Model (SSG RSM). The results of the 3D CFD simulations were compared with experimental data, particularly analyzing the difference in total temperatures between the hot and cold outlets of the vortex tube at varying static pressures at the hot outlet. Based on the analysis, all considered turbulence models are capable of detecting the total temperature separation in rotating flows. However, the standard k−ε turbulence model demonstrated the best agreement with the experimental data in terms of the degree of temperature separation. Therefore, it is recommended for use in energy separation calculations in rotating flows.
Copyright (c) 2025 Artem Karpenko, Yuriy Torba
Optimization of cooling channels of liquid rocket engines using a differential heat transfer model
The subject matter of this study is the thermophysical processes occurring in the cooling channels of liquid-propellant rocket engines. The goal of this research is to create an algorithm for optimizing cooling channels. The tasks include formulating the optimization problem and performing test calculations. The problems were solved using applied mathematics and optimization theory methods. The following results were obtained in the course of addressing the research objectives. The problem formulation was developed based on a literature review, and the structural mass was selected as the objective function. Changes in the geometric parameters of the cooling channels also influence the required pressure of the corresponding pump and, consequently, its mass. The objective function was defined as the total mass of the cooling channels and the coolant pump. The primary function of the cooling circuit is to keep the chamber wall temperature within acceptable limits. To ensure the operability of the optimized geometry, a constraint was implemented through the penalty function method. Furthermore, an optimization algorithm was developed based on the previously derived differential model of the cooling channels. Test calculations were performed using the proposed algorithm. The RD-111 engine’s gas generator and the RD-119 engine’s thrust chamber, for which data were obtained from open sources, were used as test cases. The calculations resulted in a new optimal channel geometry. In the case of the RD-119 engine chamber, the system mass was reduced by 5%. Conclusions. The scientific novelty of the obtained results consists of the development and verification of a new approach to optimizing cooling channels in liquid-propellant rocket engines. This approach is based on a previously proposed differential heat transfer model. The developed optimization algorithm simplifies the cooling system design process, thereby reducing both the time and cost of liquid-propellant rocket engine design.
Mathematical formulation of the ontology-based selection algorithm for fixed-wing unmanned aerial vehicles
The subject of this article is the formalized selection of fixed-wing unmanned aerial vehicles based on integrated ontology modeling, logical inference, and multi-criteria evaluation techniques. The goal of the research is to develop a mathematical formulation of an integrated UAV-selection algorithm that enables logical elimination of infeasible alternatives and subsequent formal ranking of feasible platforms. The tasks are as follows: to formalize the UAV domain knowledge in the form of an ontology; to develop SWRL rules for automatic verification of mission compatibility; to construct mathematical procedures for data normalization and criteria weighting; to define ranking procedures based on TOPSIS; and to demonstrate the application of the algorithm using representative UAV models. The methods used include ontology modeling in OWL2DL; logical inference based on SWRL; multi-criteria methods AHP and TOPSIS; mathematical normalization, weighted-matrix construction, computation of ideal and anti-ideal vectors, and determination of closeness coefficients. The results obtained include the development of an integrated ontology-driven mathematical model that automatically excludes infeasible UAV platforms and performs quantitative evaluation of suitable alternatives. On the example of Kub-UAV, Orlan-10, Orlan-30, and BayraktarTB2, the proposed algorithm demonstrated transparent and reproducible recommendations: BayraktarTB2 achieved the highest rating due to endurance, payload, and sensor configuration; Orlan-10 appeared optimally balanced for tactical missions; Orlan-30 was limited by endurance; Kub-UAV logically ranked last due to its loitering-munition concept. Conclusions. The scientific novelty lies in the development of the first comprehensive model combining ontology-based domain representation, logical filtering, and mathematical ranking in a single integrated framework. The practical value is associated with applicability in military and civilian decision-support systems for reconnaissance, monitoring, mapping, and other mission types. The proposed architecture is scalable and may be extended with additional criteria, fuzzy-logic techniques, and industrial data sources.
Copyright (c) 2025 Iurii Vorobiov, Kateryna Maiorova
Lossy compression of multilook SAR images in the optimal operation point neighborhood by BPG-coder
<span style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">The <strong style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">subject matter<span style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> of the article is the process of lossy compression of multilook Synthetic Aperture Radar (SAR) images corrupted by multiplicative, spatially correlated speckle noise, with a focus on operation in the neighborhood of the potential Optimal Operation Point (OOP). The <strong style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">goal<span style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> of the article is to analyze the existence and properties of the OOP for SAR image compression using the Better Portable Graphics (BPG) coder, and to develop a practical method for achieving compression near this point. The <strong style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">tasks<span style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> to be solved are: to verify the existence of the OOP for simulated Sentinel-1-like SAR images according to both traditional peak signal-to-noise ratio (PSNR) and visual quality (PSNR-HVS-M) metrics; to investigate the relationship between the compression control parameter (Q) and the resulting image quality and compression ratio (CR); and to propose and describe a practical iterative procedure for determining the Q parameter value corresponding to the OOP without requiring access to the noise-free reference image. The <strong style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">methods<span style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> used are: simulation of SAR images with speckle relative variance equal to 0.05 using noise-free Sentinel-2 data as a reference; lossy compression using the BPG coder with parameter Q varying from 1 to 51; quantitative assessment using PSNR and PSNR-HVS-M metrics; calculation of compression ratio; analysis of rate-distortion curves between different image pairs; statistical estimation of equivalent noise variance for input PSNR prediction. The following <strong style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">results<span style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;"> were obtained: It has been demonstrated that an OOP exists for the BPG coder when compressing multilook SAR images, confirmed by both PSNR and PSNR-HVS-M metrics. The OOP provides PSNR and PSNR-HVS-M values several dB higher compared to the uncompressed noisy image while achieving very high compression ratios (CR > 180). The OOP was found at high Q values (Q=48-49), where the coder aggressively suppresses noise but also introduces content distortions. A key practical result is the proposed method for determining Q at the OOP. <strong style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Conclusions<span style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">. The scientific novelty of the obtained results is as follows: For the first time, the existence of the OOP has been comprehensively demonstrated for the BPG coder applied to multilook SAR images with realistic speckle properties, considering not only the standard PSNR but also the visual quality metric PSNR-HVS-M, although the OOP is less pronounced for the latter; a method for practical OOP approximation has been developed, which operates without the need for the original noise-free (true) image, relying instead on an estimation of the speckle noise power from the available noisy data, making it applicable in real-world SAR image processing and transmission scenarios.
Copyright (c) 2025 Vladimir Lukin, Volodymyr Rebrov, Andrii Pavliuk
Modeling of the fuel mixture formation process in the channel of a gas detonation device
The gas-dynamic process of cyclic fuel mixture formation and filling it into the deminer channel is the subject of the study. This study aims to minimize the deviations of the mixture parameters from the stoichiometric composition determine the quantity, required consumption characteristics, and spatial position of the supply valves for fuel and oxidizer. The objectives of this study are to conduct numerical experiments on filling the deminer channel with the fuel mixture and to assess the quality of the resulting mixture, considering the limitations on the filling time. To solve this problem, a mathematical model of the physical process of mixing fuel components must be developed, considering the features of the gas-dynamic flow in the channels. The following results were obtained: a design of a cyclic mixture formation system that satisfies the functional requirements for the deminer’s operability, namely: filling time of 0.05 s and stoichiometric composition, was proposed. The homogeneity of the formed mixture was indirectly confirmed by experimental tests by comparing the maximum temperature values with those theoretically achievable for an ideal mixture. A qualitative and quantitative assessment of the proposed design’s technical solution is given. A mathematical model of the mixture generation process with a given component composition is created, and a series of numerical experiments are conducted. The modeling is performed using the ANSYS Fluent software. The calculation is performed in a non-stationary setting. The obtained values of the gas flow rate, pressure field, and temperature, the requirements for the valves, and their consumption characteristics are determined based on the calculation results. The modeling results showed that the proposed design solutions regarding the number, type, and mutual arrangement of the oxidant and fuel supply valves provide the required channel filling rate while maintaining the stoichiometric composition, which ensures stable combustion of the mixture in the detonation mode. The stoichiometric composition of the gas mixture was achieved with an accuracy of not less than 3%. The scientific novelty of the obtained results lies in determining the relationship between the geometric and gas-dynamic parameters of the mixer, which allows obtaining a mixture with the necessary characteristics of homogeneity for the vortex mixing method. The component composition was analyzed both in the pre-detonation chamber and in the deminer’s main channel. The ingress of oxygen into the main channel can become an additional trigger of detonation processes, which can be simulated based on the proposed mathematical model.
Copyright (c) 2025 Olga Shypul, Oleksii Pavlenko, Dmytro Brega, Vadym Garin, Oleg Tryfonov
Anthropocentric model of class scheduling in higher education institutions of aerospace profile
The subject of this article is the development of a specialized model for synthesizing academic schedules in aerospace higher education institutions (AHEI) based on fuzzy set theory and accounting for circadian rhythms, psychological load, and cognitive compatibility of disciplines for educational process participants. The research objective is to enhance the efficiency of the educational process in AHEI by supplementing scheduling tools with a multi-criteria model that ensures a balance between the technical constraints of the educational institution, the biological characteristics of participants, and the effectiveness of cognitive learning. Tasks requiring resolution include conducting a comparative analysis of existing scheduling approaches based on human factor consideration criteria, developing mathematical models of circadian activity and psychological load, creating an adaptive learning-based evolutionary optimization algorithm for schedule synthesis, and experimentally validating the proposed model. The applied formal apparatus includes mathematical modeling of biological rhythms, fuzzy set theory, genetic optimization algorithms, and machine learning methods for parameter adaptation. During the research, a multi-criteria model was developed, incorporating a circadian activity function for different age groups, a psychological load function accounting for discipline entropy and transitions between classrooms, and a cognitive compatibility matrix of disciplines. A modified genetic algorithm was created using tournament selection, two-point crossover, and local search for elite individuals. Experimental verification with student groups (n = 306) demonstrated a 13% increase in average academic performance, a 28% reduction in cognitive load, and a 39% improvement in subjective comfort assessment. The primary application domain of the developed model is scheduling for technical specialties with high cognitive load. Conclusions. The research results confirmed the relevance of an anthropocentric approach to educational process scheduling in AHEI, accounting for individual chronotypes of participants, psychological load, and cognitive compatibility of discipline sequences, and enabled optimization parameter selection justification considering the specificity of aerospace higher education institutions, chronotype distribution in student groups, and quality requirements for education. The scientific novelty of the obtained results lies in the creation of a multi-criteria schedule synthesis model that comprehensively considers circadian rhythms, psychological load, and cognitive compatibility of disciplines based on mathematical models of human biological activity, enabling increased educational process efficiency through optimal alignment of class timing with biological and psychological characteristics of participants, as well as improved knowledge acquisition quality through optimal discipline sequencing from the perspective of their cognitive compatibility.
Using Internet of Things technologies for atmospheric air pollution monitoring
Subject of Study: The article focuses on methods and tools for developing flexible distributed environmental monitoring systems for ambient air in urbanized areas and zones of high technogenic load. Objective: To enhance the reliability, timeliness, and spatial resolution of information regarding pollutant concentrations by developing architectural solutions based on modern Internet of Things (IoT) technologies, incorporating mobile measurement platforms and machine learning methods. Tasks: To analyze the limitations of existing stationary monitoring stations; to define the architecture of a hybrid monitoring system combining ground-based sensor networks and mobile segments based on Unmanned Aerial Vehicles (UAVs) to expand coverage; to perform a comparative analysis of sensor technologies, energy-efficient communication protocols (LoRaWAN, NB-IoT), and data processing platforms; to investigate the effectiveness of applying artificial intelligence algorithms to improve the measurement quality of low-cost sensors. Results: The study investigates the shortcomings of traditional monitoring systems, particularly their high cost and low coverage density. A comprehensive approach to deploying IoT systems is proposed, involving the use of distributed sensor nodes for real-time data collection. Special attention is paid to the use of Unmanned Aerial Vehicles as carriers of measurement equipment, which enables the collection of data on the vertical distribution of pollutants and monitoring in hard-to-reach places or directly in the emission plumes of pollution sources. Key challenges in implementing such systems have been identified: the accuracy of low-cost sensors, the energy efficiency of autonomous devices, and data transmission reliability in complex conditions. Scientific Novelty: The scientific novelty lies in the systematization of architectural approaches to building heterogeneous IoT environmental monitoring systems, which, unlike existing solutions, dynamically combine stationary and mobile measurement tools. The effectiveness of applying machine learning methods for automatic sensor calibration and cross-sensitivity compensation has been proven. Conclusions: Implementing the proposed IoT solutions enables a significant increase in the density of monitoring points and reduces network deployment costs. The use of UAVs ensures monitoring flexibility, while the integration of artificial intelligence facilitates the necessary measurement accuracy for decision-making.
Copyright (c) 2025 Serhii Bohdan, Andrii Zelenkov
Method of adaptive content generation in mobile applications based on personalized deep learning models
The subject matter of this article is the adaptive generation and personalization of multimedia content in mobile information systems operating under limited computing resources and intermittent connectivity constraints. Particular attention is paid to crew information support systems and onboard in-flight entertainment systems, where autonomy of operation, minimization of power consumption, and protection of flight data privacy are critical requirements. This study aims to develop a comprehensive method for adaptive content generation that seamlessly combines the global knowledge of large-scale neural models with local personalization and real-time contextual adaptation to enhance the information relevance and energy efficiency of autonomous mobile devices. The tasks to be solved are as follows: (1) to analyze existing approaches to automatic content generation and identify their architectural limitations in specific mobile environments; (2) to develop a formal stochastic model of the system, including a global level of knowledge generalization, a local level of personalization, and a level of contextual adaptation; (3) to justify the choice of methods for structural optimization of deep neural networks (specifically knowledge distillation and quantization) to ensure offline operation; (4) to develop a method of adaptive generation based on personalized federated learning and contextual optimization algorithms; and (5) to implement an experimental model of the system and verify its effectiveness on open text datasets simulating query processing under limited context conditions. The methods used are as follows: Deep Learning methods for building compact generative transformer models such as DistilGPT; Federated Learning methods for decentralized updating of model weight coefficients without transferring raw data to a server; Reinforcement Learning methods, specifically contextual multi-armed bandit algorithms, for dynamic adaptation of the generation strategy to the current flight phase or user behavior; and neural network compression methods to reduce computational load. The following results were obtained. A method of adaptive generation has been developed and software-implemented, integrating personalized federated learning with a contextual optimization mechanism. During the experimental studies conducted on text datasets simulating technical documentation and crew queries, it was established that the use of the proposed approach increases the BLEU metric’s content generation quality by 38% compared to the baseline centralized model. Optimization of the neural network architecture resulted in a reduction in response latency by 34% and a decrease in power consumption of the mobile device by 10%–15%, which is a critical indicator for autonomous onboard systems. A high level of data privacy protection (privacy loss ε < 1) was confirmed when using differential privacy mechanisms. Conclusions. The proposed method solves the scientific and applied problem of deploying intelligent generative services in closed ecosystems with high privacy and autonomy requirements, such as aviation mobile applications. The integration of federated learning with local adaptation creates conditions for the autonomous self-learning of the system without the need for constant access to cloud computing resources. The scientific novelty of the results obtained is as follows: for the first time, the method of adaptive content generation is formalized as a unified stochastic system with contextual self-adaptation, which dynamically optimizes the generation strategy through a generalized loss function that considers quality, personalization, and the contextual response of the environment, unlike existing disparate solutions.
Copyright (c) 2025 Oleksandr Vdovitchenko, Dmitro Rudenok
Model for integrating virtual reality system into the architecture of electronic commerce platforms to increase sales conversion
Copyright (c) 2025 Oleksandr Vdovitchenko, Artem Chuglazov
Methods for constructing adaptive software for educational systems
The subject of the article is a methodological basis for ensuring the adaptability of educational systems (ES) with biometric feedback to the user in real time, which ensures the personalization of the learning process. The goal is to increase the efficiency of computer-aided learning tools by developing methods for forming an ES user profile based on the integration of previous psychometric assessments of the level of training, analysis of learning results, and subsequent conversion of information about the user's state into discrete levels of complexity for the dispatching of training modules within the ES. Tasks that need to be solved are the following: to conduct a critical analysis of approaches to creating adaptive ES with biometric feedback and means of personalizing the learning process; to develop a method for forming an individual ES user profile that will ensure a rational learning trajectory, considering the specifics of the process of acquiring knowledge, skills, and abilities inherent in each individual learner; and to develop a method for assessing the current state of the ES user in real time, based on data received from mobile sensors, considering the existing operational and cost limitations of biometric monitoring devices. The following results were obtained. A method for the automated formation of the user profile of the educational software system by assessing the latent abilities of the user, using psychometric models, determining on this basis the levels of complexity of test tasks, describing typical errors, and forming a vector of the individual profile of the ES user, and a method for the online assessment of the current psychophysical state of the user were developed. The practical advantage of the developed methods is that they ensure the integration of the state assessment component into the software architectures of adaptive ES in various subject areas, based on a standardized representation of the vector of the current state of the user. Such integration can be performed in soft real-time mode in virtual reality driving training systems, pilot training simulators with the ability to monitor cognitive load in critical flight situations, in training platforms with monitoring of attention and reaction speed for operators controlling complex equipment (for example, nuclear power plant power units), training systems to support management competencies, etc. Conclusions. As a result of the conducted research, an approach was created to ensure the proper level of adaptability of the ES, through the consistent application of user personalization methods in the training process, namely the formation of their individual profile, and monitoring of the current psychophysical state in online mode. The scientific novelty of the obtained results lies in the following. For the first time, a method for the automated user profile formation of an educational software system by assessing the latent abilities of the user using psychometric models, determining on this basis the levels of complexity of tasks for the user, describing typical errors and forming a user profile vector as a formal specification of the user interface, which makes it possible to automate the process of dispatching and verifying software modules of the ES, depending on the values of the components of the vector of the individual user profile. The method of online assessment of the user's state in real time for adaptive ES has been improved, in which, unlike existing ones, an integral biometric index is formed based on the analysis of heart rate variability, heart-rate patterns are determined and, as a result, a vector of the current user state is formed, which can be represented within the framework of a software interface for the automated dispatching of software modules of the ES. The results of the experimental verification demonstrated the effectiveness of the developed methodological tools in solving problems related to increasing the efficient functioning of the ЕS.
Reactivity model of nanosatellite and UAVS embedded computing systems
The embedded computer is a key element of the avionics of both spacecraft and unmanned aerial vehicles (UAVs). Its reactivity determines the system’s ability to ensure that the reaction time to external events meets the specified real-time constraints. This study aims to investigate the reactivity of the microcontroller of the embedded computing system as a component of the overall technical efficiency of the hardware and software complex. The mathematical model of reactivity, as well as methods, tools, and technology for experimental research of the reactivity of a real-time operating system, are the subjects of this study. This study aims to develop and verify a model of the reactivity of embedded computer software for use in nanosatellites and unmanned aerial vehicles. This study substantiated the need to create a set-theoretic model of the reactivity of embedded avionics systems for small spacecraft and unmanned platforms. A constraint analysis (Worst-Case Execution Time, WCET) was performed for typical onboard computer tasks. The requirements for the model were formulated, and its mathematical description and software implementation were developed. Numerical modeling methods were used to verify the simulation results’ compliance in the actual processes in the system. Results. The proposed mathematical model of reactivity considers the stochastic characteristics of event flows and two-stage interrupt processing, allowing the probability of a timely system response to various types of events to be assessed. Experimental verification confirmed the model’s correctness and suitability for analyzing the Boryviter / Falco platform under the control of the FreeRTOS operating system. The scientific novelty lies in the development of a new concept for optimizing the work of the real-time operating system scheduler of UAV and nanosatellites OBC, which is based on a complex mathematical model of energy consumption, computational performance and reactivity of the OBC, which, unlike power consumption control mechanisms in processors with dynamic frequency or voltage regulation, is specifically focused on OBC microcontrollers, in which the frequency and voltage are fixed, and optimization is possible only through the correct choice of the policy for controlling energy-saving modes. Conclusions. The developed model can be used to assess and improve the reactivity of computing systems, including the university nanosatellite Khai-1KA and unmanned aviation systems. Further research is aimed at creating instrumental software for reactivity analysis to support software engineering of new generations of aerospace and unmanned platforms with a high level of autonomy, considering the implementation of AI/ML tools.
Copyright (c) 2025 Ihor Turkin, Oleksandr Liubimov, Lina Volobuieva