Herald of Khmelnytskyi National University. Technical sciences最新文献

{"title":"A METHOD FOR SYNTHESIZING HARDWARE AND SOFTWARE TOOLS TO ENSURE THE STABILITY OF A CORPORATE COMPUTER NETWORK","authors":"S. Lysenko, V. Sakhniuk, O. Bondaruk","doi":"10.31891/2307-5732-2023-319-1-344-350","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-344-350","url":null,"abstract":"The paper represents a method for ensuring the resilience of a corporate computer network under the influence of various types of threats. This article will provide an overview of the aspects of resilience and existing approaches to ensuring resilient routing. This article is the result of many studies and experiments, and evaluating the final result, it can be noted that this method can successfully reflect the possible importance of a node when it comes to epidemic dynamics for various network models to ensure network resilience. A possible way to solve the problem was to use the theory of linear stationary systems and the phenomenon of propagation in networks as the basis of the method. Complex interdependencies between their elements characterize various systems. The method of synthesizing hardware and software means of ensuring the stability of a corporate computer network consists of such steps as representing networks as a linear stationary system, modelling the stability of a computer network in the context of epidemics by using virtual network expansion, studying the stability of a computer network in the context of uncertain data transmission and virtual network expansion, processing input data received from the modelled computer network, etc. To solve the problem, the method involves the theory of linear stationary systems and the use of the NiR metric, which can successfully reflect the possible importance of a node when it comes to the dynamics of an epidemic for various network models to ensure network resilience. The method is tested by simulations, the results of which show a high correlation with the actual propagation dynamics modeled by SI and SIR processes. NiR also shows a small variance, which means it is reliable for different computer network topologies. The method also involves finding the most critical nodes in a computer network, for which a cascading failure model was used, which models overloaded nodes as non-functional.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114811523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EFFICIENCY ANALYSIS OF USING TYPICAL AND ATYPICAL WIND ENERGY INSTALATIONS","authors":"M. Tarasenko, Kateryna Kozak, L. Omeiza, Myroslav Zin","doi":"10.31891/2307-5732-2023-319-1-391-400","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-391-400","url":null,"abstract":"The article analyzes the energy efficiency of typical wind turbines (Savonius, Musgrave, Evans, Darier, Magnus, Lentz) and non-typical wind turbines (carousel-petal, double, powerful wind turbines operating on the basis of the Magnus effect, stationary turbine-type wind turbines, airship wind turbines filled with helium ), Sklyarov wind turbine, wind generators, constructions of various wind energy types installations in terms of axis location – vertically axial or horizontally axial, the limit value of the coefficient of wind energy utilization (СWEU), the influence of the control voltage regulator on the reliability and durability of the wind power plant, effectiveness of using confusors and guides for increasing the energy of the wind flow, the efficiency of compact derivative gears and flying wind generators, protection against lightning and overvoltage’s and noise, coefficient of wind flow inhibition etc. It also has been analyzed the effectiveness of the shape of the wind wheel blade and the rotor, the influence of the average annual wind speed and the equivalent number of hours of nominal power generation on the decision-making on the installation of powerful wind turbines, the influence of the number of blades on the speed, the energy efficiency of the wind energy installation of the Sheer Wind company, Air Grey and stationary wind generators, protection against lightning and overvoltage, an approximate determination of the capacity of any wind power plant. It has been established that the speed of the rotor rotation in wind turbines of similar power differs by several times. The number, width, and length of the blades of classic wind turbines with a horizontal axis of rotation and the speed of rotation of the rotor of wind turbines similar in power, which differ by several times, were analyzed.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128667727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"APACHE WEB SERVER RESPONSE TIME OPTIMIZATION","authors":"A. Lemeshko, Аrtem Antonenko, Oleksii Dobrovolskyi, Viacheslav Zavadskyi","doi":"10.31891/2307-5732-2023-319-1-189-201","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-189-201","url":null,"abstract":"This article explores approaches to online optimization of the Apache web server, focusing on the MaxClients parameter (which controls the maximum number of workers). Using both empirical and analytical methods, we show that MaxClients has a concave-upward effect on response time, and hence hill-climbing techniques can be used to determine the optimal value of MaxClients. We investigate two optimizers that use hill climbing—one based on Newton’s method and one based on fuzzy control. A third technique is a heuristic that exploits the relationship between bottleneck utilization and response time minimization. In all cases, online optimization reduces the response time by a factor of 10 or more compared to the static default value. The trade-offs between online schemes are as follows. Newton’s method is well known but does not provide consistent results for highly variable data such as response times. Fuzzy control is more reliable but converges slowly. The heuristic works well in our prototype system, but it can be difficult to generalize because it requires knowledge of resource bottlenecks and the ability to measure their use. This topic is relevant in the context of a rapidly growing number of web applications and high requirements for the performance and efficiency of web servers. This topic explores how to improve the speed and response time of the Apache web server using various techniques and settings, such as optimizing server settings, using caching, data compression, optimizing request routing, and more. The purpose of this research is to improve the performance and response speed of the Apache web server, which can be useful for developers and administrators of web applications and services. The speed and response time of web servers are critical factors in meeting user needs and achieving business goals for web applications and services. Apache is one of the most widely used web servers in the world, so optimizing the response time of the Apache server is an important task for many developers and administrators of web applications and services. This study will examine various approaches and techniques for optimizing the response time of the Apache web server, including configuring server parameters, using caching, data compression, optimizing request routing, and others. The results of the study can be useful for developers and administrators of web applications and services that deal with the use of the Apache web server. Optimizing Apache server response time can significantly improve the performance and efficiency of web applications and services, which in turn can lead to user satisfaction and business goals.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"8 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134445357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SIMULATION OF THE PROCESS OF FILLING POLYSTYRENE FOAM FOUNDRY MOLD WITH THE METAL","authors":"Y.V. Savytskyi","doi":"10.31891/2307-5732-2023-319-1-263-267","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-263-267","url":null,"abstract":"Modern approaches to prefabrication production consist in the maximum approximation of the shape and size of the blanks to the finished part, which essentially makes the final part cheaper. One of the methods of precision casting is casting in gasified models, or foam models. The basis is the task of developing a theoretical model of filling a polystyrene foam model with liquid metal. The analysis of the process of filling the mold with a gasified model and the process of filling the mold with a closed sprue system are considered. The analysis of the obtained solutions shows that the movement of the metal has the character of aperiodic oscillations. The speed of metal in quantity is maximum at the initial moment of metal processing in the form and happens as it is filled. The pressure of the steam-gas mixture at the initial moment of time exceeds the pressure of the weak metal in the riser, which provides the possibility of metal ejection from the bowl. At the same time, the pressure in the mold cavity changes little with the increase in gas permeability of the mold, which is explained by the small gap between the melting front of the model and the metal mirror. However, with an increase in gas permeability due to a decrease in back pressure, the speed of the metal in the mold cavity and the path traveled by it increase. The analysis of the system of equations allows predicting the behavior of metal during the design of molds for the summer, which reduces the probability of production defects.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130571476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"INFORMATION SYSTEM OF IDENTIFICATION OF TERMS AND ABBREVIATIONS IN TEXT DOCUMENTS","authors":"Vitalii Danylyk, V. Lytvyn, Solomiya Mushasta","doi":"10.31891/2307-5732-2023-319-1-81-83","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-81-83","url":null,"abstract":"The paper examines the process of building and functioning of the system for identifying terms and abbreviations in text documents. The task of developing such a system is urgent, since such an identification problem often arises in the military sphere. During the implementation of the system, it was taken into account that a single term or abbreviation may have several explanations in different regulatory documents. All available explanations are added to the term or abbreviation, which is taken into account during the operation of the system. A feature of the system is the use of natural language processing methods, since terms can be found in different cases. To implement the system, ready-made Python packages were used to cover similar tasks: Tkinter, PyMuPDF Examples of the system’s functioning are given. The developed system is used in practice. In the process of completing the work, the research of problems and the search for solutions for the tasks is carried out, an information system is developed for the processing of documents with the aim of integrating definitions of potentially unknown terms and abbreviations into them, in order to enable officers to use any literature without problems, because all terms and abbreviations will be known. To generalize the documentation, all the necessary requirements for the system are defined, and in order to correctly create the architecture and allocate the functional tasks of the system under development, a system analysis is performed and a conceptual model is built. Using all the specified information, all the necessary diagrams are built using the UML notation. Diagrams depict the relationships between objects and the overall architecture of the system. The architecture of the system is built in such a way that the component systems and the system as a whole can be easily expanded. At the end of the development, testing and implementation of the project is carried out. The process of operation of the components of the system on the part of the end user and the process of deployment by the end user of the information system are described. The object of the study is the presence of slowing factors in the process of command and control carried out by commanders of tactical units, which can slow down decision-making and also affect their correctness. The subject of the study is to solve the problems of the appearance of slowing factors in the process of command and control carried out by commanders of tactical units, by means of work with military data.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124993862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"METHOD OF LOCAL RESTORATION OF SEGMENTS OF INFORMATION SIGNALS","authors":"A. Voloshko, T. Dzheria","doi":"10.31891/2307-5732-2023-319-1-64-69","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-64-69","url":null,"abstract":"The use of centralized and decentralized electricity supply schemes, the introduction of feedback between the consumer of electricity and its producer led to a rapid increase in information flows at all stages of the functioning of the electricity industry of Ukraine, starting with the production of electricity and before its consumption. This necessitates the processing, storage and transmission of large data sets. On the other hand, the time constraints imposed on information processing and decision-making efficiency, as well as the limited bandwidth of communication networks require effective optimization of information flows in terms of their compression and compact storage, transmission and recovery without loss. At the same time, the determining quantitative and qualitative information parameters are electricity consumption modes and the quality of electric energy, and the main mode parameter for solving many problems of planning, management and carrying out commercial calculations is the graphs of electric load. Based on the analysis of the functional relationships of wavelet coefficients according to the levels of wavelet decomposition, the robot presents a modified reconstruction scheme and developed a model based on which a method of local (segmental) restoration of information signals according to the levels of wavelet detail is synthesized using the example of the electric load graph. In the paper, a model of local recovery of time segments of information signals is proposed and a sequential algorithm of actions synthesized on its basis. This technique allows for effective segmentation of information signals, reduces the duration of mathematical processing, simplifies database analysis, increases the effectiveness of controlling the reliability of initial data recovery by reserving recovery paths with subsequent comparison of results.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127459334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CLUSTER ANALYSIS OF PARAMETRIC GRADATION OF CONTROL MEASUREMENTS OF CLOTHING FOR WOMEN OF LARGE SIZES","authors":"A. Slavinska, O. Syrotenko, Victoriia Mytsa, O. Dombrovska","doi":"10.31891/2307-5732-2023-319-1-276-283","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-276-283","url":null,"abstract":"The preservation of the functional properties of the sewing product is regulated by technical regulatory documentation. The insufficient filling of the market with an assortment of clothes for women of large sizes is explained by the complexity of the geometry of the body surface, which is regulated by different approaches to the classification of sizes in the current anthropometric standards. The study of the dimensional variability of the range of large-sized figures in clusters of the main and additional dimensions of outerwear was carried out taking into account the synchronization of complete groups. Harmonization of the typology was carried out by cross-comparing the limitations of the size scale taking into account the type of figure M in the table of dimensions of the technical documentation. Body prototype M, height 168 cm, chest girth 110, 116 cm was chosen based on the frequency of occurrence in 10 models of women’s dresses. Graphical interpretation of absolute deviations characterizes the synchronicity of preservation of anthropometric commensurability at all levels of application of regulatory documentation. Numerical series of displacement values of 9 control measurements were formed for standardizing the basis of deviations for 4 regulatory documents based on the principle of combining in pairs. Confirmed synchronicity of preservation of anthropometric proportionality at all levels of application of regulatory documentation: figure-structure-product.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129299044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MODEL OF A CHAOTIC ULTRA-WIDEBAND INFORMATION TRANSMISSION SYSTEM FOR WIRELESS SENSOR NETWORKS","authors":"Maksym Slobodian","doi":"10.31891/2307-5732-2023-319-1-284-288","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-284-288","url":null,"abstract":"Distributer measuring systems, consisting of interconnected wireless sensor nodes with autonomous supply, have plenty of applications in different areas of engineering end technology. Therefore, wireless sensor network design and optimization is a vital problem in informational technologies and computer engineering. Regardless of particular application and architecture, a wireless sensor network consists of several small sensor nodes somehow distributed in an area of inspection. Such a design ensures a distributed parameter measuring, according to which, each node performs preprocessing procedures for the data, which are to be aggregated by a so-called sink node and sent via other networks, e.g., wired or wireless local area network. For healthcare solutions, it is important to ensure a stable connection with the network and server back-end to provide a high-level analysis based on predicting methods of machine learning algorithms. This paper describes an application of an ultra-wideband communication model based on chaos synchronization as a low-power and efficient alternative solution for building wireless sensor networks. Thus, using chaotic signals as information carriers in wireless communication has several advantages, including a wide smooth spectrum, high information capability, cybersecurity, and low power consumption. The synchronization problem is one of the most vital tasks to be solved to design a chaos application for ultra-wide-band communication. Being well-studied for periodic signals, modern synchronization theory contains plenty of solutions for classical telecommunication and radio engineering systems, however, it is not developed enough for chaotic systems. Hence, a one-directional dissipative synchronization between two Chen systems is studied in the first section. The second section is devoted to the computer simulation of the model, described in the previous section. All the models built and the simulations performed have been done using MATLAB/Simulink software. The negative impact of channel noise and inequality of system parameters is considered. The possible way how to improve technical characteristics is also provided. Proposed models are to be used to design and develop low-cost wireless sensor networks for multi-channel healthcare solutions.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126679557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"APPLYING DATA CLUSTERING METHODS FOR CREATING TARGETING USER GROUPS FOR REAL ESTATE","authors":"Olexandr Tkachyk","doi":"10.31891/2307-5732-2023-319-1-300-307","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-300-307","url":null,"abstract":"In this paper applied unsupervised clustering to a dataset examines the application of k-means clustering to create target user groups for a real estate platform. The goal is to segment the user base into meaningful groups to better understand their preferences and behaviors, and tailor marketing campaigns and product features to the needs of each group. The key step in the application of k-means clustering to real estate data is data preparation. Real estate data can be particularly messy and incomplete, and thus requires careful cleaning and normalization before clustering can be applied. Data preparation includes several key steps, such as removing irrelevant or redundant features, creating new features as feature scaling is also an important step in data preparation. K-means clustering is sensitive to the scale of the data, so features may need to be normalized to ensure that they are on the same scale, handling missing or erroneous data, and scaling or transforming features to ensure they are on the same scale. Dataset of 2000 customers interested in real estate with the various types of data was taken as a basis. Then the data was observed, investigated and based on results it was prepared for clustering by doing data cleaning as irrelevant data or empty data points may include features that do not significantly contribute to the clustering process, data normalization as it is necessary to ensure that all features are on the same scale, feature selection to determine most relevant features for clustering, feature encoding and dimensionality reduction which was achieved through principal component analysis (PCA). By carefully cleaning, normalizing, and selecting relevant features, clustering algorithms such as k-means were applied more effectively and target user groups were identified.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122132928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"METHOD OF AUTOMATED DETECTION OF ARTICLE TERMS USING A DECISION TREE","authors":"A. Synko, P. Zhezhnych","doi":"10.31891/2307-5732-2023-319-1-338-343","DOIUrl":"https://doi.org/10.31891/2307-5732-2023-319-1-338-343","url":null,"abstract":"Every day, the number of users of virtual communities is increasing, and therefore the data that occurs during communication between them. The posted data can contain valuable information because they contain not only the manufacturer’s opinion, but also consumer experience about a certain product. But, due to the fact that virtual communities have a weak structure in terms of providing information, they are more focused on entertaining content – they may contain data that do not carry a meaningful load, and also, when placing data, not all users foresee techniques that will help increase the relevance of the search for this data. Therefore, the search for target data requires significant time costs. To improve the search for data in the article, a method is proposed that allows you to analyze the content of posted posts and identify keywords from a certain subject area. This method is automated and works on the basis of a previously developed dictionary of key phrases or regular expressions with weighting coefficients of belonging to one or another term. As a result, a decision-making tree is built for each term, which determines the weight of the term to the content of the post, article. At the same time, the level of location of the post in the discussion is taken into account, because the discussion contains a set of chronologically ordered posts. Posts placed at higher levels have a higher coefficient in the calculation. While posts are placed at lower levels – lower weighting factors. Identified key phrases before the specified term are ordered in descending order of weight. At each level of the tree, the total weight of key phrases must be equal to one. To process the data from the virtual communities, they were downloaded using the data consolidation technique. As a result, the concept of consolidated data storage was introduced, which allows collecting data from disparate sources. The paper presents the weight calculation for one term from part of the CodeProject community post.","PeriodicalId":386560,"journal":{"name":"Herald of Khmelnytskyi National University. Technical sciences","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121254461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}