Мікросистеми, Електроніка та Акустика: науково-технічний журнал, Т. 28, № 2(124)
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Документ Відкритий доступ Real-Time Correcon of the Frequency Response of a Public Address System(КПІ ім. Ігоря Сікорського, 2023) Dvornyk, O. O.Correcng the public address (PA) system during a concert event is one of the crucial tasks in ensuring acousc comfort. However, the exisng approaches to such correcon do not allow for real-me adaptaon to changes in the acousc properes of the venue that occur during the event. To address this limitaon, this arcle proposes the use of a mulband compressor. It is shown that a zero-latency VST plugin can serve as a mulband compressor. Pink noise can be used as a test signal for system calibraon. The results of tesng the proposed algorithm, conducted through model and real-world experiments, demonstrate the feasibility and effecveness of the proposed approachДокумент Відкритий доступ The Method of Preprocessing of ECG Signals for Detecon of Atrial and Ventricular Late Potenals(КПІ ім. Ігоря Сікорського, 2023) Mnevets, A. V.; Ivanushkina, N. H.This article is aimed at analyzing and improving the methods of preprocessing ECG signals for the task of detecting low-amplitude regular components. This study analyzed the main advantages and disadvantages of existing ECG signal preprocessing methods for the detection of late ventricular and atrial potentials. Based on this analysis, a cardiac cycle averaging method was proposed in order to increase the accuracy of detection of late potentials by various algorithms and improve the quality of preprocessing of the ECG signal aimed at detection of low-amplitude components. The main feature of the proposed method is the division of a large number of cardiocycles for averaging into smaller aggregates (epochs), and the subsequent application of linear matrix decomposition to suppress irregular inclusions. Also, when dividing into epochs, it can be used overlapping. It can reduce the difference between epochs, and increase the number of cardiocycles for averaging. The use of this approach allows to minimize irregular inclusions in the ECG signal and increase the accuracy of the selection of low-amplitude late potentials. In addition, the division into epochs and overlapping makes possible to avoid blurring of low-amplitude high-frequency components during averaging as a result of heart rate variability, as well as to improve the quality of averaging with a reduced number of cardiocycles. To test the proposed method, various approaches were used to assess the ECG signal preprocessing. Mostly, we compared the cardiac cycles obtained as a result of different averaging algorithms and the proposed method with the template. To test the averaging method, an artificial ECG signal was developed with existing noise, late ventricular and atrial potentials, heart rate variability, and a high-amplitude component that occurs at a random location every two heartbeats. The template cardiac cycle was obtained from the original artificial signal without any distortion or noise. Firstly, we visually compared and evaluated different averaging methods with the template. Secondly, we calculated the similarity metrics of the late potentials on the averaged cardiac cycle with the late potentials on the template signal. Based on these metrics, the curves of dependence of the similarity values on the amplitude of late potentials on the ECG signal were calculated. Thirdly, we evaluated the impact of the proposed aver aging method on the classification results of various machine learning algorithms on real ECG signals with available late potentials. The overall testing result showed that the proposed averaging method is able to reproduce the morphology of low-amplitude regular components by 10-30% more accurately and improve the classification accuracy by 5-12%.Документ Відкритий доступ Research of the Characteriscs of a Convoluonal Neural Network on the ESP32-CAM Microcontroller(КПІ ім. Ігоря Сікорського, 2023) Sharuiev, R. D.; Popovych, P. V.The paper is devoted to solving the problem of using neural networks for real-time image recognition on lowpower portable devices running on microcontrollers. The ESP-32 CAM microcontroller was used as the target device, on which an artificial neural network was deployed, written using the Python programming language and the Tensorflow library for building neural networks. The performance of the microcontroller and personal computer for object detection using a neural network and their classification were compared in the paper. The image recognition time and percentage of correctly classified objects were compared. The paper shows that the number of training epochs affects the accuracy of object classification in the image. The obtained results show that increasing the number of training epochs increases the accuracy of object recognition using the studied neural network, but a significant increase in the number of epochs does not significantly improve recognition accuracy. The difference in the obtained results for the microcontroller and personal computer image recognition accuracy ranges from 5%.Документ Відкритий доступ Мікромініатюрні сенсори тиску на основі діодних структур(КПІ ім. Ігоря Сікорського, 2023) Клименко, В. A.; Семікіна, Т. В.В роботі проведено детальний аналіз сучасних мікромініатюрних датчиків тиску виконаних на різноманітних діодних структурах. Показані можливі області застосування таких датчиків, їх головні переваги та недоліки. Про ведено дослідження діодних гетероструктур на основі CdS / ZnS / CuS / CdTe та показано перспективність використання датчиків тиску на основі цих матеріалів в якості аналогу існуючих напівпровідникових приладів. На основі проведених експериментальних досліджень обґрунтовано, що ці структури є п’єзоелектричними. Наведені конструктивні схеми досліджених структур та їх вольт-амперні характеристики. Описані можливі області застосування таких структур. Надані конструктивні схеми та параметри отриманих діодних структур можуть бути цікавими для широкого кола фахівців в області сенсорної техніки та автоматизації різноманітних технологічних процесів виготовлення мікроелектронної апаратури. Показано, змінюючи технології виготовлення датчиків та концентрацію хімічних елементів в отриманих плівках можна змінювати чутливість датчика та динамічний діапазон його роботи, пристосовуючи параметри датчика до галузі його застосування в відповідній вимірювальній електронній апаратурі та в системах контролю тиску.Документ Відкритий доступ Fuel Cell Hybridizaon Topologies Using Various Energy Storage Technologies(КПІ ім. Ігоря Сікорського, 2023) Bevza, I. O.The main idea of this work is to review and classify the currently existing fuel cell (FC) hybridization topologies with various energy storage technologies (lithium-ion batteries (LIBs), supercapacitors (SCs), and lithium-ion capacitors (LICs)). There are presented generalized topologies of FC hybridization using LIB/SC or LIC. Also, when analyzing the energy storage technologies presented on the market, a comparison was made of LIB, SC, and LIC characteristics in the form of tables and Ragone plot. As a result, perspectives for the development of hybrid FC technologies using LIC were proposed due to the most advantageous characteristics compared to other energy storage methods.