Вісник НТУУ "КПІ". Серія Радіотехніка, Радіоапаратобудування

Постійне посилання на фонд

https://ela.kpi.ua/handle/123456789/2120

ISSN 2310-0389 (Online), ISSN 2310-0397 (Print) Періодичність: 4 рази на рік
Рік заснування: 1956
Тематика: теоретична радіотехніка; електродинаміка; теорія та засоби телекомунікацій; антени та пристрої НВЧ діапазону; теорія та практика радіовимірювань; конструювання радіоапаратури; мікроелектронна та наноелектронна техніка; технологія радіоапаратобудування; засоби та методи мультимедіа; засоби захисту інформації; електронна побутова апаратура; цифрова та обчислювальна техніка; радіоелектроніка біомедичних технологій.
Офіційний сайт: https://radap.kpi.ua/radiotechnique

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Зараз показуємо 1 - 20 з 955

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77 ГГц радар для автомобіля
(НТУУ «КПІ», 2012) Ляшук, О. М.; Lyashuk, O. M.; Ляшук, А. Н.
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A Computational Model of Electrophysiological Properties of Cardiomyocytes
(КПІ ім. Ігоря Сікорського, 2018) Ivanushkina, N. G.; Ivan’ko, E. O.; Prokopenko, Yu. V.; Redaelli, A.; Tymofieiev, V. I.; Visone, R.; Іванушкіна, Н. Г.; Іванько, К. О.; Прокопенко, Ю. В.; Редаеллі, А.; Тимофєєв, В. І.; Вісоне, Р.; Иванушкина, Н. Г.; Иванько, Е. О.; Прокопенко, Ю. В.; Редаэлли, А.; Тимофеев, В. И.; Висонэ, Р.
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A Method for Calculating and Compensating Frequency-Phase Distortions at the Junction and in Signal Fragments With Nonlinear Frequency Modulation
(КПІ ім. Ігоря Сікорського, 2025) Kostyria, О. O.; Hryzo, А. A.; Fedorov, А. V.; Lisohorskyi, B. A.; Ushakov, S. I.
The use of nonlinear frequency modulated signals in radar technology is due to the possibility of reducing the maximum level of the side lobes of their autocorrelation functions compared to linear frequency modulated signals. One of the promising areas of development of the theory of synthesis of signals with nonlinear frequency modulation is the study of a thin signal structure that is distorted when switching to a new signal fragment. In particular, it was found that jumps in instantaneous frequency and phase at the boundary between fragments cause additional distortions in the frequency-phase structure in subsequent fragments. These phenomena had previously been ignored by researchers. Previous work on the development and study of mathematical models of nonlinear frequency-modulated signals has revealed regularities that describe the change in the frequency-phase structure of the next fragment when the value or order of the oldest derivative of the instantaneous phase function changes. It is found that the number of components in the distortion spectrum is determined by the order of this derivative: for phase distortions — according to its value, for frequency distortions — by one less. Constant components have a physical interpretation and correspond to jumps in instantaneous frequency or phase at the boundary of fragments. The structure of the paper is determined by the research logic. The first section of the paper analyzes the available publications and shows that there is no research in this area. This substantiates the expediency and relevance of the research task set forth in the second section. The third section is devoted to the theoretical substantiation of the main provisions: the calculation expressions for determining the components of frequency-phase distortion in cases where the order of the instantaneous phase function does not change with the transition to a new fragment, increases by one or two. In further research, it is planned to consider the case when the order of the instantaneous phase function decreases with the transition to the next fragment of a nonlinear frequency-modulated signal.
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Advanced Edge Detection Techniques for Enhanced Diabetic Retinopathy Diagnosis Using Machine Learning
(КПІ ім. Ігоря Сікорського, 2024) Basarab, M. R.; Ivanko, K. O.
Diabetic retinopathy (DR) represents one of the most serious complications associated with diabetes mellitus, posing a significant threat to vision and leading to severe impairment and potential blindness if not diagnosed and treated promptly. The study investigates the integration of advanced edge detection techniques with machine learning algorithms to enhance the precision and effectiveness of DR diagnosis. By leveraging the APTOS 2019 Blindness Detection dataset, the research employs a combination of edge detection methods such as the Sobel operator and the Canny edge detector, alongside advanced preprocessing techniques and sophisticated feature extraction methods. The study reveals that the synergy between these edge detection techniques and machine learning significantly boosts the diagnostic accuracy of neural networks. Specifically, the accuracy for multiclass classification (spanning five categories: No diabetic retinopathy, Mild, Moderate, Severe, and Proliferative diabetic retinopathy) improved from 78.5% to an impressive 88.2%. This marked enhancement underscores the potential of these techniques in refining the diagnostic processes for early DR detection. By improving the accuracy of classification, this approach not only facilitates early intervention but also plays a crucial role in reducing the risk of severe vision loss among patients with diabetes. The findings of this study emphasize the importance of integrating advanced image processing techniques with machine learning frameworks in medical diagnostics. The improved outcomes demonstrated in this research highlight the potential for such technological advancements to contribute meaningfully to the field of ophthalmology, leading to better patient care and potentially transforming the standard of practice in DR diagnosis.
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Analysis of a Two-Stage Thyristor Rectifier Topology with Parallel Bridges for Reactive Power Reduction
(КПІ ім. Ігоря Сікорського, 2026) Komarov, V. F.; Rassokhina, Yu. V.
High-power phase-controlled thyristor DC drives, despite their reliability, have a fundamental drawback: significant reactive power consumption from the supply network, especially in dynamic operating modes with large firing angles (α). This leads to a low Displacement Power Factor (DPF) and additional losses. This study analyzes a cost-effective novel two-stage thyristor rectifier topology proposed to mitigate this problem. The topology utilizes a special transformer with secondary winding taps (e.g., at 50% and 100% voltage) that feed two 6-pulse bridges (R1 and R2), connected in parallel to a common DC load. The system functions as a high-speed solid-state equivalent of an On-Load Tap Changer (OLTC). By sequentially engaging the bridges, the converter maintains small firing angles (α) over a wide output voltage range. A detailed analysis of the energy characteristics, based on a case study of a typical acceleration cycle for a high-inertia drive (hoisting machine), demonstrates the topology's energy efficiency. Compared to a conventional single-bridge thyristor rectifier, the two-stage scheme reduces the total reactive energy consumed per acceleration cycle by 51% (from 54.4 kVAr · h to 26.8 kVAr · h in the example). An additional advantage of the solution is the reduction of the Root-Mean-Square (RMS) primary winding current during the initial acceleration stage, which leads to lower active power (I2R) losses in the transformer and supply lines. A drawback of the considered commutation algorithm is the presence of a 'discontinuous current mode' in the transformer primary winding during the mixed-mode (simultaneous operation of R1 and R2), which significantly degrades the harmonic spectrum (THD) of the input current, making the converter non-compliant with power quality standards (e.g., IEEE 519). The study concludes that practically implementing this energy-efficient topology requires hardware adaptation, specifically through the design of a custom Inter-Phase Reactor (IPR) or integration into multi-pulse configurations, to mitigate harmonic distortion while preserving the reactive power benefits.
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Analysis of Chi-Squared Divergence Changes by Filtering of Stego Images Formed According to UNIWARD Embedding Methods
(КПІ ім. Ігоря Сікорського, 2019) Progonov, D. O.
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Analysis of the Efficiency of the Kalman-Type Correlation Algorithm for Tracking of a Small UAV in the Presence of Uncorrelated
(КПІ ім. Ігоря Сікорського, 2021) Herasymenko, A. O.; Zhuk, S. Ya.
The article shows the relevance of the problem of development and analysis of algorithms for tracking small-sized UAVs according to video surveillance. A Kalman-type correlation algorithm for tracking of a small-sized UAV in the presence of spatially uncorrelated interference, which is the most common in practice, is synthesized. In the obtained algorithm, the UAV motion parameters are estimated independently along the axes of a rectangular coordinate system. Positioning accuracy analysis using the correlation algorithm, as well as the correlation algorithm for tracking UAVs based on the Kalman filter, was carried out by statistical modeling in the Matlab programming environment.
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Application of the «Endless Train» Method for the SDN Controller OpenDayLight
(КПІ ім. Ігоря Сікорського, 2017) Скулиш, М. А.; Skulysh, M. A.; Скулыш, М. А.
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Automated Precision Amplitudes and Phases Measurement of Polyharmonic Eddy Current Signals of Non-destructive Testing
(КПІ ім. Ігоря Сікорського, 2023) Bazhenov, V. G.; Kalenychenko, Yu. O.; Ratsebarskiy, S. S.; Gloinik, K. A.
The development of electronic systems like Field-Programmable Gate Array (FPGA) made them available for mass commercial use. This created conditions for the development and application of software and technical tools implemented on FPGA algorithms for fast processing of digital signals. Such solutions, in turn, opened up new opportunities for the spread of multi-frequency eddy current systems (МFЕС) for non-destructive testing (NDT) in the form of systems for simultaneous processing of digital signals of different frequencies, which allows MFEC to effectively compete with pulsed eddy current systems (PEC). This work presents a new algorithm for accurate digital measurement of the MFEC amplitude and phase of harmonic components of polyharmonic signals, which is implemented in hardware and software on FPGA. The measurement of the amplitude and phase of harmonic components is based on the method of orthogonal processing of digital signals, to increase the accuracy of which the necessity of fulfilling the condition of multiplicity of the sampling sequence to the size of the digital signal period has been proved. Compliance with this condition is achieved by adjusting the length of the sampling sequence, which in the proposed algorithm is performed before orthogonal processing. The influence of inaccuracy in setting the length of the sampling sequence on the size of measurement errors when determining the amplitude and phase of the harmonic components of the signal is simulated. As a result of the simulation, it was established that when the multiplicity condition is met, the measurement error significantly decreases, which indicates the high efficiency of our algorithm. The achieved accuracy of measuring the amplitude of harmonic components and the phase of polyharmonic signals due to the given hardware and software implementation of the algorithm makes it possible to create inexpensive, compact, scalable automated digital systems, the measurement data of which can be used both to determine the individual characteristics of the object and to reconstruct three-dimensional images, i.e. in tomographic systems.
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Calculation Model for Optoelectronic Remote Sensing System’s Radiometric Resolution at Arbitrary Viewing Angles
(КПІ ім. Ігоря Сікорського, 2017) Kolobrodov, V. H.; Lykholit, M. I.; Mykytenko, V. I.; Tiagur, V. M.; Dobrovolska, K. V.; Колобродов, В. Г.; Лихоліт, М. І.; Микитенко, В. І.; Тягур, В. М.; Добровольська, К. В.; Колобродов, В. Г.; Лихолит, Н. И.; Микитенко, В. И.; Тягур, В. Н.; Добровольская, Е. В.
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CJFET Differential Pairs Constructions and Characteristics for Design of CBiCJFet Differential Amplifiers and Differential Difference Amplifiers
(КПІ ім. Ігоря Сікорського, 2019) Savchenko, E. M.; Drozdov, D. G.; Rodin, V. G.; Grushin, А. I.; Dukanov, P. А.; Prokopenko, N. N.
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Classification of Structural and Functional Development Stage of Cardiomyocytes Using Machine Learning Techniques
(КПІ ім. Ігоря Сікорського, 2024) Bondarev, V. R.; Ivanko, K. O.; Ivanushkina, N. G.
The study is dedicated to the problem of classification of structural and functional development stage of cardiomyocytes derived from the induced pluripotent stem cells with application of the digital image processing methods and machine learning algorithms, in particular, neural networks. Cell regenerative therapy has become one of the most promising treatment options for patients with heart failure. But since cardiomyocytes are objects with a high level of complexity and have significant morphological variability, automatic classification is complicated by the lack of implemented methods. That's why researches in this area are a major global public health priority. The initial data set used in this study is a publicly open set of confocal microscopic images of cardiomyocytes which can be divided into five classes based on the morphological features (the structure of the transverse T-tubule). A small amount of input data leads to the need of using augmentation methods. Methods that prevent the alteration of the transverse T-tubule, which is an important parameter for correct classification of the development of cardiomyocytes, are used. Histogram equalization technique is used to enhance the contrast and dynamic range of the confocal microscopic images with the method of contrast-limited adaptive equalization. This helped to improve the local contrast of the analyzed images and highlight the main elements of the cardiomyocyte. Finally, Chan–Vese method, which belongs to the regional segmentation methods, is chosen for the image segmentation and removing artifacts and/or parts of other cells from the image. A pre-processed and augmented dataset is used for training of the convolutional neural network having an architecture with hierarchical structure and residual block usage. The model is evaluated based on the confusion matrix and the heat maps of different convolutional layers are analyzed. Images from the classes with a large number of mutual errors are also considered. Based on the analysis, several classes of structural and functional development of cardiomyocytes are combined. Final accuracy of the model for defining the cardiomyocytes maturation stage achieved 77%.
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Comparison of Monopolar and Bipolar Cox-Maze Ablation Based on Clinical Data and Mathematical Modeling
(КПІ ім. Ігоря Сікорського, 2020) Stasiuk, Y. P.; Sychyk, M. M.; Maksymenko, V. B.; Kravchuk, B. B.
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Comprehensive Reliability Assessment Technique of Telecommunication Networks Equipment with Reducible Structure
(КПІ ім. Ігоря Сікорського, 2020) Mogylevych, D. I.; Kononova, I. V.; Kredentser, B. P.; Karadschow, I.
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Computational Approaches for Emotional Burnout Detection: Machine Learning and Deep Learning Evaluation
(КПІ ім. Ігоря Сікорського, 2026) Mushta, S. A.; Mushta, I. A.; Popov, A. O.; Lysenko, O. M.; Tukaiev, S. V.
This study focuses on the development and evaluation of computational techniques for classifying emotional burnout based on quantitative data analysis. Instead of relying on subjective psychometric questionnaires, we investigate the applicability of machine learning and deep learning algorithms to structured datasets. Several classical methods, including logistic regression, random forest, and gradient boosting, were systematically compared with a Deep Learning (DL) ensemble model. To enhance robustness, preprocessing steps such as feature selection, data balancing, and resampling were applied. The deep learning architecture, incorporating focal loss and adaptive threshold optimization, achieved the best performance. On 5-fold cross-validation, the proposed DL model obtained an overall accuracy of 86.3%, with precision of 0.815/0.887, recall of 0.786/0.904, and F1-scores of 0.800/0.895 for the negative and positive classes respectively. The results demonstrate that advanced computational models can provide scalable and generalizable tools for automatic detection tasks, forming a technical foundation for future integration into applied research and occupational health monitoring systems.
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Computer Modelling Technologies of Optical System of Polarizing Thermal Imager
(КПІ ім. Ігоря Сікорського, 2020) Kolobrodov, V. H.
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Control of the Modified Chaotic Chua’s Circuit Using Threshold Method
(КПІ ім. Ігоря Сікорського, 2018) Rusyn, V. B.; Pribylova, L.; Dimitriu, D.-G.
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Controlled Brewster effect in the scattering of electromagnetic waves on pseudo-rotating lattices of dielectric resonators
(КПІ ім. Ігоря Сікорського, 2023) Trubin, O. O.
Various conditions for the occurrence of anomalous scattering, in which most of the power is emitted by the lattice only in the direction of propagation of the incident wave, are analyzed. An analytical model for the scattering of plane electromagnetic waves on arrays of pseudo-rotating dielectric resonators (DRs) of cylindrical and rectangular shape is developed. New analytical relations are derived for the functions that determine the coupling between the field of a plane wave and the main types of magnetic oscillations of the rotated DR. The angles between the axis of the DR and the directions of propagation of plane waves, at which the coupling between the DR and the incident wave reaches extreme values, are studied. The conditions of non-resonant scattering and scattering with the absence of a reflected petal, known as the Brewster effect, were established. The general relations between the angles of inclination of DRs, polarization and the angles of incidence of waves on lattices, which lead to special cases of scattering, were found. There is a similarity between non-resonant scattering and the known Malyuzhynets effect, which describes the passage of waves through lattices of other types. Scattering models for lattices of rotated cylindrical and rectangular DRs were built. The difference between the classical Brewster effect and the petal-free cases of scattering on lattices built on the basis of the use of pseudo-rotating DRs was noted. In particular, it’s shown that, unlike other methods of realizing metasurfaces of this class, cases of scattering without petals on lattices of pseudorotating resonators are possible when the angles of incidence are changed in a wider band. The obtained theoretical results allow us to propose a new class of devices built on the basis of the use of pseudo-rotating DRs, to significantly reduce the calculation time and to optimize complex multi-resonator structures. New types of lattices built on pseudo-rotating DRs can be used to design a wide class of antennas, as well as multiplexing devices in terahertz, infrared, and optical wavelength range communication systems.
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Coupled Oscillations of Rectangular Lattices of Dielectric Resonators (Analytical Solutions)
(КПІ ім. Ігоря Сікорського, 2025) Trubin, A. A.
The frequency spectra and amplitude distributions of the natural oscillation fields of the same shape and dimensions coupled dielectric resonator (DR) systems, located in one-, two-, and three-dimensional rectangular lattices, are considered. Neglecting the coupling between non-adjacent resonators, general analytical solutions are found for the linear homogeneous system of equations proposed earlier for describing natural oscillations of coupled DR systems. An algorithm based on perturbation theory for solving systems of equations of coupled oscillations of identical DRs is proposed, which allows reducing the solution to the calculation of determinants of tridiagonal and pentadiagonal matrices. It’s shown that parameters of coupled oscillations of rectangular structures are determined through simple distributions of amplitudes and frequencies characteristic of Bloch waves of quantum particles in a periodic potential. Using the derived general analytical formulas, the calculated frequencies are compared with the natural oscillation frequencies obtained by numerical methods. For the first time, a general analytical solution is found for the distribution of amplitudes and frequencies of a rectangular lattice with DR doubly degenerate types of natural oscillations. It’s shown that in the case of zero coupling between degenerate oscillations of different types, the obtained analytical formulas transform into expressions describing the oscillations of DRs in simple rectangular lattices. General conditions are formulated, under which the solution of the equations for coupled oscillations of DR systems can be found in analytical form. It’s shown that under the specified conditions, the distribution of the amplitudes of coupled oscillations of identical DR lattices with degenerate and non-degenerate types of eigenoscillations are interconnected to each other. In this case, a new method for calculating the amplitudes and frequencies of coupled oscillations of DR lattices with degenerate oscillations is proposed. The obtained formulas allow us to estimate in general terms the characteristics of the spectrum of eigenoscillations with an increasing in the number of resonators. Several examples demonstrate a very good coincidence of the found analytical and numerical results. The obtained theoretical conclusions significantly simplify the calculation and optimization of scattering parameters of various communication devices in the microwave, infrared and optical wavelength ranges, which are built based on the use of rectangular DR structures.
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Coupling coefficients of different cylindrical dielectric resonators in the open space
(КПІ ім. Ігоря Сікорського, 2016) Trubin, A. A.

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