Iurii Krak

Prof. Dr. Iurii Krak

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Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 April 2024 in Cogent Engineering
Verified
Journal Article
Open access
ABAlibek Barlybayev
Alibek Barlybayev
NANurzada Amangeldy
Nurzada Amangeldy
BKBekbolat Kurmetbek
Bekbolat Kurmetbek
IKIurii Krak
Iurii Krak
BRBibigul Razakhova
Bibigul Razakhova
RTRakhila Turebayeva
Rakhila Turebayeva

17 January 2023 in Entropy
Verified
Journal Article
Open access
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OBOleh Bisikalo
Oleh Bisikalo
Vyacheslav S. KharchenkoVyacheslav S. Kharchenko
Vyacheslav S. Kharchenko
Viacheslav KovtunViacheslav Kovtun
Viacheslav Kovtun
IKIurii Krak
Iurii Krak
SPSergii Pavlov
Sergii Pavlov
The article analytically summarizes the idea of applying Shannon’s principle of entropy maximization to sets that represent the results of observations of the “input” and “output” entities of the stochastic model for evaluating variable small data. To formalize this idea, a sequential transition from the likelihood function to the likelihood functional and the Shannon entropy functional is analytically described. Shannon’s entropy characterizes the uncertainty caused not only by the probabilistic nature of the parameters of the stochastic data evaluation model but also by interferences that distort the results of the measurements of the values of these parameters. Accordingly, based on the Shannon entropy, it is possible to determine the best estimates of the values of these parameters for maximally uncertain (per entropy unit) distortions that cause measurement variability. This postulate is organically transferred to the statement that the estimates of the density of the probability distribution of the parameters of the stochastic model of small data obtained as a result of Shannon entropy maximization will also take into account the fact of the variability of the process of their measurements. In the article, this principle is developed into the information technology of the parametric and non-parametric evaluation on the basis of Shannon entropy of small data measured under the influence of interferences. The article analytically formalizes three key elements: -instances of the class of parameterized stochastic models for evaluating variable small data; -methods of estimating the probability density function of their parameters, represented by normalized or interval probabilities; -approaches to generating an ensemble of random vectors of initial parameters.

18 February 2020 in Computational Intelligence
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Journal Article
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IKIurii Krak
Iurii Krak
OBOlexander Barmak
Olexander Barmak
Eduard ManziukEduard Manziuk
Eduard Manziuk

31 August 2023 in Applied Sciences
Verified
Journal Article
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OKOleg Kalyta
Oleg Kalyta
OBOleksandr Barmak
Oleksandr Barmak
Pavlo RadiukPavlo Radiuk
Pavlo Radiuk
IKIurii Krak
Iurii Krak
Modern video surveillance systems mainly rely on human operators to monitor and interpret the behavior of individuals in real time, which may lead to severe delays in responding to an emergency. Therefore, there is a need for continued research into the designing of interpretable and more transparent emotion recognition models that can effectively detect emotions in safety video surveillance systems. This study proposes a novel technique incorporating a straightforward model for detecting sudden changes in a person’s emotional state using low-resolution photos and video frames from surveillance cameras. The proposed technique includes a method of the geometric interpretation of facial areas to extract features of facial expression, the method of hyperplane classification for identifying emotional states in the feature vector space, and the principles of visual analytics and “human in the loop” to obtain transparent and interpretable classifiers. The experimental testing using the developed software prototype validates the scientific claims of the proposed technique. Its implementation improves the reliability of abnormal behavior detection via facial expressions by 0.91–2.20%, depending on different emotions and environmental conditions. Moreover, it decreases the error probability in identifying sudden emotional shifts by 0.23–2.21% compared to existing counterparts. Future research will aim to improve the approach quantitatively and address the limitations discussed in this paper.

14 January 2025 in Technologies
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Journal Article
Open access
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OKOleksii Kovalchuk
Oleksii Kovalchuk
OBOleksandr Barmak
Oleksandr Barmak
Pavlo RadiukPavlo Radiuk
Pavlo Radiuk
LKLiliana Klymenko
Liliana Klymenko
IKIurii Krak
Iurii Krak
Cardiovascular diseases are the leading cause of death globally, highlighting the need for accurate diagnostic tools. To address this issue, we introduce a novel approach for arrhythmia detection based on electrocardiogram (ECG) that incorporates explainable artificial intelligence through three key methods. First, we developed an enhanced R peak detection method that integrates domain-specific knowledge into the ECG, improving peak identification accuracy by accounting for the characteristic features of R peaks. Second, we proposed an arrhythmia classification method utilizing a modified convolutional neural network (CNN) architecture with additional convolutional and batch normalization layers. This model processes a triad of cardio cycles—the preceding, current, and following cycles—to capture temporal dependencies and hidden features related to arrhythmias. Third, we implemented an interpretation method that explains CNN’s decisions using clinically relevant features, making the results understandable to clinicians. Using the MIT-BIH database, our approach achieved an accuracy of 99.43%, with F1-scores approaching 100% for major arrhythmia classes. The integration of these methods enhances both the performance and transparency of arrhythmia detection systems.

27 October 2019
Verified
Book Chapter
Closed access
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IKIurii Krak
Iurii Krak
OBOlexander Barmak
Olexander Barmak
Eduard ManziukEduard Manziuk
Eduard Manziuk
AKAnatolii Kulias
Anatolii Kulias