Browsing by Author "Zhurba, Anna O."

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Development of a JFET Model with Increased Accuracy: Measurements of Wrangling Data, Acquisition and Model Analysis
(CEUR-WS Team, Aachen, Germany, 2025) Hnatushenko, Viktoriia V.; Guda, Anton I.; Zimoglyad, Andrew Yu.; Zhurba, Anna O.
ENG: Junction gate field – effect transistors have a significant role in the modern electronics. Simulation of the electronic schematics is a crucial part of the modern devices development. At the present time an existent model are used. A drawbacks of the exiting JFET models, with are commonly used during electronic schematics simulation a described. For the tasks of precision simulation the simple approximation functions and switching conditions lead to accuracy loss. A general purpose and specialized hardware and software complex was created to acquire measurement data. This measurement complex gives as possibility to acquire measurement data in automatic and semi-automatic modes. A bulk amount of data about selected JFET species was collected. According to this data a new model was proposed. This model allows us identify parameters in sequence, which significantly decreases the possibility of the identification errors. Proposed model requires more complex calculations to achieve results, and more data to conduct parametric identification. But as the result, new model provides better agreement with experimental data, especially in low-voltage regimes. New model allows us to decrease simulation error level from the 20% to 1—5%. The proposed model provides better qualitative conforming to the experimental data.
Development of Software Module for Analysis of It Specialists’ Labor Market
(Odesa National University of Technology, 2022) Dub, Anhelina; Zhurba, Anna O.
ENG: The paper describes how software module was developed to analyze the labor market of IT professionals using the Python programming language in the integrated programming environment. The software module screens, crawls, parses and exports data from specialised sites. The software module allows to find, structure and export data to CSV and TXT files. The sample of key parameters was investigated by means of business analytics. The developed program can be expanded with additional functions, supplemented by a graphical interface, uploaded to the web hosting. The software module provides processing of a large array of unstructured information from vacancy announcement sites, reduces the amount of routine manual operations and provides an opportunity to focus stakeholders’ attention on key priorities. The aim of the work is to develop a parsing software module for automated collection and analysis of open position data to determine which knowledge and skills are most important for employers in the IT industry.
Fractal Analysis of Satellite Night-Time Imagery for Environmental and Urban Monitoring
(ISPRS, Hannover, Germany, 2025) Hnatushenko, Viktoriia V.; Zhurba, Anna O.; Hnatushenko, Volodymyr V.
ENG: Satellite remote sensing technologies offer a powerful means for acquiring high-resolution imagery that captures both natural and anthropogenic features across large geographic regions. One particularly valuable application of satellite data is the analysis of night-time lights, which reflect human activity, urban infrastructure and energy consumption. Traditional image processing methods often struggle to describe the irregular and complex geometries inherent to urban environments and natural landscapes. This research proposed the application of fractal analysis as a methodological tool for characterizing such complexity in night-time satellite images. By applying this to satellite images of Ukraine and the city of Kyiv before and after major attacks on energy infrastructure, it demonstrated how reductions in night-time illumination correspond with significant decreases in fractal dimension. Additionally, the method was applied to assess urban expansion in Dubai and Dnipro across multi-decadal periods. Results show a correlation between increased urbanization and changes in fractal characteristics, providing evidence that fractal metrics can serve as proxies for urban morphology and development. Fractal analysis as an effective method for environmental monitoring, crisis assessment, and urban planning opens pathways for integrating fractal parameters into larger geospatial intelligence systems and provides a foundation for further research on scale-invariant properties of urban and ecological patterns in satellite imagery.
Research on Environmental Changes Based on Fractal Characteristics of Satellite Images
(CEUR-WS Team, Aachen, Germany, 2025) Hnatushenko, Viktoriia V.; Zhurba, Anna O.; Zimoglyad, Andrew Yu.; Ostrovska, Kateryna Yu.
ENG: Most natural structures that are widely studied today using computer science have a complex fractal structure. Fractal analysis of such structures is used to model, study, and explain the properties of surfaces and structures of complex objects in various fields of science and technology. Images of a large number of natural surfaces and structures are satellite images that exhibit fractal properties. Satellite images in modern life have high spatial resolution, which gives researchers and users satisfactory initial data for solving various types of problems. A promising direction for increasing the informativeness of satellite images is the use of fractal image analysis methods. The complexity of the forms of the underlying surface and vegetation can be described using the fractal dimension. Characteristic values of the fractal dimension allow decoding of space images. The paper proposes a method for studying environmental changes in satellite images based on the calculation of fractal characteristics, such as fractal dimension, fractal distribution and fractal segmentation. The ecological indicators for assessing the state of the environment were selected as trends in forest numbers, water and land resources. Satellite images of the Amazon forests, Bolivia in 1991, 1996, 2006, 2012, 2016, 2020, which were subjected to mass deforestation, were selected for the study. The experimental results show that the fractal dimension increases each time (Fractal Dimension (FR) = 1.441 in 1991, FR = 1.825 in 2020), and the green areas in this area decrease. The depth of the seas (Black Sea, Tyrrhenian Sea, Mediterranean Sea, Philippine Sea) was studied. The least homogeneous with the largest amplitude of distribution modes has the fractal distribution of the Philippine Sea, which indicates a more pronounced relief of the seabed. As a result of the study of winter fields with different levels of snow cover, it was found that an increase in its value leads to an increase in the value of the fractal dimension (FR=1.702 February, FR=1.894 March). Thus, fractal analysis of winter fields allows us to estimate the relative amount of moisture that will enter the soil in the spring. The study highlights the need for further research in developing more efficient fractal methods to improve the accuracy of change area detection, which will favor the analysis of the causes and consequences of the environmental situation.