V. Barannik, A. Krasnorutsky, V. Kolesnyk, V. Barannik, Sergii Pchelnikov, Pavlo Zeleny
Subject research in the article is the methods of compressing video images under conditions of ensuring the desired level of their fidelity in the delivery process using infocommunication networks. The goal is to develop methods of encoding video images for increasing the level of their compression in the conditions of ensuring required reliability. Task: to substantiate the approach regarding the structural clusterization of transformed video segments in the conditions of preserving their reliability; to develop a method of structural and statistical coding of transformants in the spectral-cluster space; conduct a comparative evaluation of the effectiveness of various methods of encoding video segments. The methods used: mathematical models for estimating the amount of statistical and structural redundancy in the clustered spectral space of video segments; methods of statistical coding. The following results have been obtained. The potential effectiveness of representing a transformant in clustered space by the number of series of units in binary description of their components has been substantiated. A method of structural-statistical coding in the spectral-cluster space has been created. The basic component of this technological approach is the evaluation of the estimates regarding the potential ability to eliminate various types of redundancy in the current cluster. Here, the amount of redundancy is reduced considering the statistical and structural features of the cluster. The comparative evaluation revealed the advantages of the created method over coding methods in standardized platforms. The advantage is achieved in terms of the peak signal-to-noise ratio by at least 30%. and in terms of a compression ratio by an average of 12 %. Conclusions. The scientific novelty of the obtained results is as follows: for the first time, a method of structural-statistical coding of video segments in spectral space based on their clusterization has been created. The differences of the method lie in the fact that the component of the transformant is simultaneously interpreted as an element of the statistical and combinatorial cluster space; the potential capabilities of eliminating various types of redundancy in the clustered transformant are considered. This provides an increase in the level of compression of video images for a given level of reliability.
{"title":"Method of compression and ensuring the fidelity of video images in infocommunication networks","authors":"V. Barannik, A. Krasnorutsky, V. Kolesnyk, V. Barannik, Sergii Pchelnikov, Pavlo Zeleny","doi":"10.32620/reks.2022.4.10","DOIUrl":"https://doi.org/10.32620/reks.2022.4.10","url":null,"abstract":"Subject research in the article is the methods of compressing video images under conditions of ensuring the desired level of their fidelity in the delivery process using infocommunication networks. The goal is to develop methods of encoding video images for increasing the level of their compression in the conditions of ensuring required reliability. Task: to substantiate the approach regarding the structural clusterization of transformed video segments in the conditions of preserving their reliability; to develop a method of structural and statistical coding of transformants in the spectral-cluster space; conduct a comparative evaluation of the effectiveness of various methods of encoding video segments. The methods used: mathematical models for estimating the amount of statistical and structural redundancy in the clustered spectral space of video segments; methods of statistical coding. The following results have been obtained. The potential effectiveness of representing a transformant in clustered space by the number of series of units in binary description of their components has been substantiated. A method of structural-statistical coding in the spectral-cluster space has been created. The basic component of this technological approach is the evaluation of the estimates regarding the potential ability to eliminate various types of redundancy in the current cluster. Here, the amount of redundancy is reduced considering the statistical and structural features of the cluster. The comparative evaluation revealed the advantages of the created method over coding methods in standardized platforms. The advantage is achieved in terms of the peak signal-to-noise ratio by at least 30%. and in terms of a compression ratio by an average of 12 %. Conclusions. The scientific novelty of the obtained results is as follows: for the first time, a method of structural-statistical coding of video segments in spectral space based on their clusterization has been created. The differences of the method lie in the fact that the component of the transformant is simultaneously interpreted as an element of the statistical and combinatorial cluster space; the potential capabilities of eliminating various types of redundancy in the clustered transformant are considered. This provides an increase in the level of compression of video images for a given level of reliability.","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44035026","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}
This article discusses the problem of ensuring the protection of user data in information systems. It is shown that classic information systems are represented by stationary and mobile communication devices focused on data exchange with digital space. The fundamental principles of user data exchange in the digital space are considered. It has been established that leading technology IT corporations collect data from user communication devices. It is shown that the organization of data collection is carried out by redirecting the DNS traffic of the communication device to the DNS servers of IT corporations, followed by its encryption using the DoH protocol. This makes it impossible for authorized services and departments of national states to control the users’ DNS traffic and ensures the monopoly position of IT corporations in the global digital market for collecting and analyzing user data. It is shown that the collection of user data is carried out with the aim of further monetization and influencing decisions made by users. DNS traffic of devices for communication with the digital space of the Internet is fixed. An audit of the recorded DNS traffic was performed, and as a result, specialized Internet resources were identified to be responsible for collecting and processing user data. It has been proved that the identified specialized Internet resources belong to IT corporations. Methods of identification of communication devices in digital space were considered. It is shown that the identification of communication devices is based on the collection of a unique set of data from each communication device. Based on each unique data set, a digital fingerprint of the communication device is formed, which is used for its further identification in the digital space. These approaches allow organizing protection against user data collection in information systems. Software and hardware implementations for protection against data collection from communication devices are proposed. It has been experimentally established that the combined use of the proposed software and hardware models provides the most effective protection against data collection from communication devices and does not affect the functionality of information systems.
{"title":"Research of potential data leaks in information and communication systems","authors":"Оlexander Zadereyko, O. Trofymenko, Yuliia Prokop, Nataliia Loginova, Anastasiia Dyka, Serhii Kukharenko","doi":"10.32620/reks.2022.4.05","DOIUrl":"https://doi.org/10.32620/reks.2022.4.05","url":null,"abstract":"This article discusses the problem of ensuring the protection of user data in information systems. It is shown that classic information systems are represented by stationary and mobile communication devices focused on data exchange with digital space. The fundamental principles of user data exchange in the digital space are considered. It has been established that leading technology IT corporations collect data from user communication devices. It is shown that the organization of data collection is carried out by redirecting the DNS traffic of the communication device to the DNS servers of IT corporations, followed by its encryption using the DoH protocol. This makes it impossible for authorized services and departments of national states to control the users’ DNS traffic and ensures the monopoly position of IT corporations in the global digital market for collecting and analyzing user data. It is shown that the collection of user data is carried out with the aim of further monetization and influencing decisions made by users. DNS traffic of devices for communication with the digital space of the Internet is fixed. An audit of the recorded DNS traffic was performed, and as a result, specialized Internet resources were identified to be responsible for collecting and processing user data. It has been proved that the identified specialized Internet resources belong to IT corporations. Methods of identification of communication devices in digital space were considered. It is shown that the identification of communication devices is based on the collection of a unique set of data from each communication device. Based on each unique data set, a digital fingerprint of the communication device is formed, which is used for its further identification in the digital space. These approaches allow organizing protection against user data collection in information systems. Software and hardware implementations for protection against data collection from communication devices are proposed. It has been experimentally established that the combined use of the proposed software and hardware models provides the most effective protection against data collection from communication devices and does not affect the functionality of information systems.","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44758982","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}
The subject of study is the Green's functions of the first and second boundary value problems for the Laplace equation. The study constructs the Green's functions of the first and second boundary value problems for the Laplace equation in space with a spherical segment in analytical form, as well as numerical analysis of these functions. Research task: to formalize the problem of determining Green's functions for the specified domain; using methods of Fourier, pair summation equations and potential theory to reduce mixed boundary value problems for auxiliary harmonic functions to a system of equations that has an analytical solution; investigate the compatibility of the algebraic system for determining constants of integration; formulate and prove a theorem about the jump of the normal derivative of the potential of a simple layer on the surface of a segment, with the help of which to present the Green's function in the form of the potential of a simple layer; conduct a numerical experiment and identify algorithms and areas of changing the parameters of effective calculations; analyze the behavior of Green's functions. Scientific novelty: for the first time, Green's functions of Dirichlet and Neumann boundary value problems for the Laplace equation in three-dimensional space with a spherical segment were constructed in analytical form, the obtained results were substantiated, and a comprehensive numerical experiment was conducted to analyze the behavior of these functions. The obtained results: mixed boundary value problems in the interior and exterior of the spherical surface to which the segment belongs are set for the auxiliary harmonic functions; using the Fourier method, the problem is reduced to systems of paired equations in series by Legendre functions, the solutions of which are found using discontinuous Mehler-Dirichlet sums. The specified functions are obtained in an explicit view in two forms: series based on the basic harmonic functions in spherical coordinates and the potential of a simple layer on the surface of the segment. To substantiate the results, the lemma on the compatibility of the algebraic system for determining the constants of integration and the theorem on the jump of the normal derivative of the potential of a simple layer on a segment are proved. A numerical experiment was conducted to analyze the behavior of the constructed functions. Conclusions: the analysis of numerical values of Green's functions obtained by different algorithms showed that the highest accuracy of results outside the surface of the segment was obtained when using images of Green's functions in the form of series. On the basis of the calculations, the lines of the level of the Green's functions of two boundary value problems in the plane of the singular point, as well as the graphs of the potential density of the simple layer for the Dirichlet problem and the potential jump for the Neumann problem on the segment at different locations of the sin
{"title":"Green's functions of the first and second boundary value problems for the Laplace equation in the nonclassical domain","authors":"O. Nikolaev, O. Holovchenko, Nina Savchenko","doi":"10.32620/reks.2022.4.03","DOIUrl":"https://doi.org/10.32620/reks.2022.4.03","url":null,"abstract":"The subject of study is the Green's functions of the first and second boundary value problems for the Laplace equation. The study constructs the Green's functions of the first and second boundary value problems for the Laplace equation in space with a spherical segment in analytical form, as well as numerical analysis of these functions. Research task: to formalize the problem of determining Green's functions for the specified domain; using methods of Fourier, pair summation equations and potential theory to reduce mixed boundary value problems for auxiliary harmonic functions to a system of equations that has an analytical solution; investigate the compatibility of the algebraic system for determining constants of integration; formulate and prove a theorem about the jump of the normal derivative of the potential of a simple layer on the surface of a segment, with the help of which to present the Green's function in the form of the potential of a simple layer; conduct a numerical experiment and identify algorithms and areas of changing the parameters of effective calculations; analyze the behavior of Green's functions. Scientific novelty: for the first time, Green's functions of Dirichlet and Neumann boundary value problems for the Laplace equation in three-dimensional space with a spherical segment were constructed in analytical form, the obtained results were substantiated, and a comprehensive numerical experiment was conducted to analyze the behavior of these functions. The obtained results: mixed boundary value problems in the interior and exterior of the spherical surface to which the segment belongs are set for the auxiliary harmonic functions; using the Fourier method, the problem is reduced to systems of paired equations in series by Legendre functions, the solutions of which are found using discontinuous Mehler-Dirichlet sums. The specified functions are obtained in an explicit view in two forms: series based on the basic harmonic functions in spherical coordinates and the potential of a simple layer on the surface of the segment. To substantiate the results, the lemma on the compatibility of the algebraic system for determining the constants of integration and the theorem on the jump of the normal derivative of the potential of a simple layer on a segment are proved. A numerical experiment was conducted to analyze the behavior of the constructed functions. Conclusions: the analysis of numerical values of Green's functions obtained by different algorithms showed that the highest accuracy of results outside the surface of the segment was obtained when using images of Green's functions in the form of series. On the basis of the calculations, the lines of the level of the Green's functions of two boundary value problems in the plane of the singular point, as well as the graphs of the potential density of the simple layer for the Dirichlet problem and the potential jump for the Neumann problem on the segment at different locations of the sin","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41881354","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}
The subject of study in this article is the evaluation of the performance issues of cloud services implemented using FPGA technology. The goal is to improve the performance of cloud services built on top of multiple FPGA platforms known as FPGA-as-a-Service (FaaS). Task: to analyze the delays in communications between host computer and FPGA; propose the steps of development to reduce the delay and perform the evaluation of the response time for the FPGA-based accelerator depending on number of involved cards; consider the reliability aspect of such systems implemented using programmable logic. According to the tasks, the following results were obtained. The FPGA-as-a-Service where FPGA resources are provided through a set of hardware/software toolset is considered. The usage of queueing theory for cloud-based services is analyzed. The contribution of the parts of FPGA-as-a-Service to the final delay of the service is discussed. The process of modeling of work the services based on FPGA accelerator cards with use of Jackson's network is analyzed in detail. The model of the delays of FaaS that considers the parameters of accelerator FPGA cards is offered. The formula of the total response time of the service combined based on the response of the components of is obtained. The proposed steps of reduce data processing delays include increase the size of data blocks for processing in FPGA by each kernel, change the communication model with kernel from sequential to pipelined, following timing closure technique and use more FPGA accelerator cards in parallel to divide the enquiring delay. Based on the proposed model the evaluation of response time of FaaS was done. The advantage of the use of many FPGAs in parallel for same data processing task instead of implementation of requests thread for each accelerator card is shown. Conclusions. The main contribution of this study is a step forward to the modeling of FPGA-based services that can be used for FPGA-based artificial intelligence (AI) applications. It helps to improve the performance of the system by means of reducing the delays at different stages of requests processing. Another side of this result is the reliability aspect that is based on modified manner of service operation in case of use the proposed steps of system optimization. It helps to improve the processing of requests to FaaS. The proposed method is the next step after prototyping of such systems because it helps to turn the FaaS from the object for development to the tool for deployment of new technologies like AI applications.
{"title":"Method of QoS evaluation of FPGA as a service","authors":"A. Perepelitsyn, Vitaliy Kulanov, Inna Zarizenko","doi":"10.32620/reks.2022.4.12","DOIUrl":"https://doi.org/10.32620/reks.2022.4.12","url":null,"abstract":"The subject of study in this article is the evaluation of the performance issues of cloud services implemented using FPGA technology. The goal is to improve the performance of cloud services built on top of multiple FPGA platforms known as FPGA-as-a-Service (FaaS). Task: to analyze the delays in communications between host computer and FPGA; propose the steps of development to reduce the delay and perform the evaluation of the response time for the FPGA-based accelerator depending on number of involved cards; consider the reliability aspect of such systems implemented using programmable logic. According to the tasks, the following results were obtained. The FPGA-as-a-Service where FPGA resources are provided through a set of hardware/software toolset is considered. The usage of queueing theory for cloud-based services is analyzed. The contribution of the parts of FPGA-as-a-Service to the final delay of the service is discussed. The process of modeling of work the services based on FPGA accelerator cards with use of Jackson's network is analyzed in detail. The model of the delays of FaaS that considers the parameters of accelerator FPGA cards is offered. The formula of the total response time of the service combined based on the response of the components of is obtained. The proposed steps of reduce data processing delays include increase the size of data blocks for processing in FPGA by each kernel, change the communication model with kernel from sequential to pipelined, following timing closure technique and use more FPGA accelerator cards in parallel to divide the enquiring delay. Based on the proposed model the evaluation of response time of FaaS was done. The advantage of the use of many FPGAs in parallel for same data processing task instead of implementation of requests thread for each accelerator card is shown. Conclusions. The main contribution of this study is a step forward to the modeling of FPGA-based services that can be used for FPGA-based artificial intelligence (AI) applications. It helps to improve the performance of the system by means of reducing the delays at different stages of requests processing. Another side of this result is the reliability aspect that is based on modified manner of service operation in case of use the proposed steps of system optimization. It helps to improve the processing of requests to FaaS. The proposed method is the next step after prototyping of such systems because it helps to turn the FaaS from the object for development to the tool for deployment of new technologies like AI applications.","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43790925","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}
IEEE 802.11 wireless local area networks (WLANs) are shared networks, which use contention-based distributed coordination function (DCF) to share access to wireless medium among numerous wireless stations. The performance of the distributed coordination function mechanism mostly depends on the network load, number of wireless nodes and their data rates. The throughput unfairness, also known as performance anomaly is inherent in the very nature of mixed data rate Wi-Fi networks using the distributed coordination function. This unfairness exhibits itself through the fact that slow clients consume more airtime to transfer a given amount of data, leaving less airtime for fast clients. In this paper, we comprehensively examine the performance anomaly in multi-rate wireless networks using three approaches: experimental measurement, analytical modelling and simulation in Network Simulator v.3 (NS3). The results of our practical experiments benchmarking the throughput of a multi-rate 802.11ac wireless network clearly shows that even the recent wireless standards still suffer from airtime consumption unfairness. It was shown that even a single low-data rate station can decrease the throughput of high-data rate stations by 3–6 times. The simulation and analytical modelling confirm this finding with considerably high accuracy. Most of the theoretical models evaluating performance anomaly in Wi-Fi networks suggest that all stations get the same throughput independently of the used data rate. However, experimental and simulation results have demonstrated that despite a significant performance degradation high-speed stations still outperform stations with lower data rates once the difference between data rates becomes more significant. This is due to the better efficiency of the TCP protocol working over a fast wireless connection. It is also noteworthy that the throughput achieved by a station when it monopolistically uses the wireless media is considerably less than 50 % of its data rate due to significant overheads even in most recent Wi-Fi technologies. Mitigating performance anomaly in mixed-data rate WLANs requires a holistic approach that combines frame aggregation/fragmentation and adaption of data rates, contention window and other link-layer parameters.
{"title":"Theoretical and experimental study of performance anomaly in multi-rate IEEE802.11ac wireless networks","authors":"Fash Safdari, A. Gorbenko","doi":"10.32620/reks.2022.4.06","DOIUrl":"https://doi.org/10.32620/reks.2022.4.06","url":null,"abstract":"IEEE 802.11 wireless local area networks (WLANs) are shared networks, which use contention-based distributed coordination function (DCF) to share access to wireless medium among numerous wireless stations. The performance of the distributed coordination function mechanism mostly depends on the network load, number of wireless nodes and their data rates. The throughput unfairness, also known as performance anomaly is inherent in the very nature of mixed data rate Wi-Fi networks using the distributed coordination function. This unfairness exhibits itself through the fact that slow clients consume more airtime to transfer a given amount of data, leaving less airtime for fast clients. In this paper, we comprehensively examine the performance anomaly in multi-rate wireless networks using three approaches: experimental measurement, analytical modelling and simulation in Network Simulator v.3 (NS3). The results of our practical experiments benchmarking the throughput of a multi-rate 802.11ac wireless network clearly shows that even the recent wireless standards still suffer from airtime consumption unfairness. It was shown that even a single low-data rate station can decrease the throughput of high-data rate stations by 3–6 times. The simulation and analytical modelling confirm this finding with considerably high accuracy. Most of the theoretical models evaluating performance anomaly in Wi-Fi networks suggest that all stations get the same throughput independently of the used data rate. However, experimental and simulation results have demonstrated that despite a significant performance degradation high-speed stations still outperform stations with lower data rates once the difference between data rates becomes more significant. This is due to the better efficiency of the TCP protocol working over a fast wireless connection. It is also noteworthy that the throughput achieved by a station when it monopolistically uses the wireless media is considerably less than 50 % of its data rate due to significant overheads even in most recent Wi-Fi technologies. Mitigating performance anomaly in mixed-data rate WLANs requires a holistic approach that combines frame aggregation/fragmentation and adaption of data rates, contention window and other link-layer parameters.","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46543502","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}
Serhii Berdnyk, A. Gomozov, D. Gretskih, Viktor Kartich, M. Nesterenko
The results of an analytical review of literature sources on the use of approximate boundary conditions for electromagnetic fields of impedance type in solving boundary value problems of electromagnetism for more than 80 recent years are presented. During this period, the impedance approach was generalized to various electrodynamic problems, in which its use made it possible to significantly expand the limits of mathematical modeling, which adequately considers the physical properties of real boundary surfaces. More than eighty years have passed since the publication of approximate boundary conditions for electromagnetic fields. The meaning and value of these conditions lies in the fact that they allow solving diffraction problems about fields outside well-conducting bodies without considering the fields inside them, which greatly simplifies the solution. Since then, numerous publications have been devoted to the application of impedance boundary conditions, the main of which (according to the authors) are presented in this paper. Particular attention is paid to the characteristics of electrically thin impedance vibrators and film-type surface structures as a personal contribution of the authors to the theory of impedance boundary conditions in electromagnetism. The subject of research in this article is the analysis of the limits and conditions for the correct application of impedance boundary conditions. The goal is to systematize the results of using the concept of approximate impedance boundary conditions for electromagnetic fields in problems of electrodynamics based on an analytical review of literature sources. The following results were obtained. The types of metal-dielectric structures are presented, for which methods of theoretical determination of the values of surface impedances for film-type structures are currently known, which are the most promising for creating technological control elements on their basis in centimeter and millimeter wavelength devices. Conclusions. The materials of this paper do not pretend to be a complete reference book covering all the results and aspects of the development of the concept of approximate impedance type boundary conditions in problems of electromagnetism over the past decades. Simultaneously, the authors hope that the information presented in this paper will be useful to specialists in the field of theoretical and applied electrodynamics, as well as graduate students, young scientists and students who are just mastering radiophysics and radio engineering specialties.
{"title":"Approximate boundary conditions for electromagnetic fields in electrodmagnetics","authors":"Serhii Berdnyk, A. Gomozov, D. Gretskih, Viktor Kartich, M. Nesterenko","doi":"10.32620/reks.2022.3.11","DOIUrl":"https://doi.org/10.32620/reks.2022.3.11","url":null,"abstract":"The results of an analytical review of literature sources on the use of approximate boundary conditions for electromagnetic fields of impedance type in solving boundary value problems of electromagnetism for more than 80 recent years are presented. During this period, the impedance approach was generalized to various electrodynamic problems, in which its use made it possible to significantly expand the limits of mathematical modeling, which adequately considers the physical properties of real boundary surfaces. More than eighty years have passed since the publication of approximate boundary conditions for electromagnetic fields. The meaning and value of these conditions lies in the fact that they allow solving diffraction problems about fields outside well-conducting bodies without considering the fields inside them, which greatly simplifies the solution. Since then, numerous publications have been devoted to the application of impedance boundary conditions, the main of which (according to the authors) are presented in this paper. Particular attention is paid to the characteristics of electrically thin impedance vibrators and film-type surface structures as a personal contribution of the authors to the theory of impedance boundary conditions in electromagnetism. The subject of research in this article is the analysis of the limits and conditions for the correct application of impedance boundary conditions. The goal is to systematize the results of using the concept of approximate impedance boundary conditions for electromagnetic fields in problems of electrodynamics based on an analytical review of literature sources. The following results were obtained. The types of metal-dielectric structures are presented, for which methods of theoretical determination of the values of surface impedances for film-type structures are currently known, which are the most promising for creating technological control elements on their basis in centimeter and millimeter wavelength devices. Conclusions. The materials of this paper do not pretend to be a complete reference book covering all the results and aspects of the development of the concept of approximate impedance type boundary conditions in problems of electromagnetism over the past decades. Simultaneously, the authors hope that the information presented in this paper will be useful to specialists in the field of theoretical and applied electrodynamics, as well as graduate students, young scientists and students who are just mastering radiophysics and radio engineering specialties.","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48166842","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}
A. Chukhray, Michael Chernenko, Tetiana Stoliarenko, Oleksandr Leshchenko
This article describes a solution for learning how to build the method of frequency characteristics of the control object. Nowadays, the level of competencies required in the work of a modern engineer is becoming higher and higher, and the more difficult it is to provide the necessary level of knowledge and skills using only the traditional approach. This problem can be solved by implementing automated learning systems that will relieve teachers, reach more students, and unify the quality of work. The subject of the research is the possibility of building a certain abstract system that will be able to provide complex skills for students in an automatic mode. The basis for this research is a complex task that requires various skills from the learner. As a system that requires well-developed skills, we can cite the system of construction of the frequency characteristics of the control object. This work studied the methods for building such systems, as well as to study the learning ability of students and for extracting the most frequent and possible errors of students. The goal is to design and run a system that allows the student to acquire skills in constructing the frequency characteristics of an object. This work allows use of one of the possible methods for implementing such a task, as well as identifying the most common problems at the stage of learning this technique and the most successful method to prepare the system for use. In the process of the task, the following results were obtained: student errors were identified and classified. Based on the signal-parametric approach to the diagnosis of faults in dynamic systems, mathematical diagnostic models were created, that allow the system to identify classes of errors by comparing the calculation results of the student and the calculation results of the system. The peculiarities of the application of the proposed diagnostic models are presented. The intelligent tutor system is developed and used in practical classes on "Theory of automatic control" by third-year students of the National Aerospace University “Kharkiv Aviation Institute”.
{"title":"Diagnostic support of intelligent tutor system for teaching skills to construct control object frequency characteristics","authors":"A. Chukhray, Michael Chernenko, Tetiana Stoliarenko, Oleksandr Leshchenko","doi":"10.32620/reks.2022.3.14","DOIUrl":"https://doi.org/10.32620/reks.2022.3.14","url":null,"abstract":"This article describes a solution for learning how to build the method of frequency characteristics of the control object. Nowadays, the level of competencies required in the work of a modern engineer is becoming higher and higher, and the more difficult it is to provide the necessary level of knowledge and skills using only the traditional approach. This problem can be solved by implementing automated learning systems that will relieve teachers, reach more students, and unify the quality of work. The subject of the research is the possibility of building a certain abstract system that will be able to provide complex skills for students in an automatic mode. The basis for this research is a complex task that requires various skills from the learner. As a system that requires well-developed skills, we can cite the system of construction of the frequency characteristics of the control object. This work studied the methods for building such systems, as well as to study the learning ability of students and for extracting the most frequent and possible errors of students. The goal is to design and run a system that allows the student to acquire skills in constructing the frequency characteristics of an object. This work allows use of one of the possible methods for implementing such a task, as well as identifying the most common problems at the stage of learning this technique and the most successful method to prepare the system for use. In the process of the task, the following results were obtained: student errors were identified and classified. Based on the signal-parametric approach to the diagnosis of faults in dynamic systems, mathematical diagnostic models were created, that allow the system to identify classes of errors by comparing the calculation results of the student and the calculation results of the system. The peculiarities of the application of the proposed diagnostic models are presented. The intelligent tutor system is developed and used in practical classes on \"Theory of automatic control\" by third-year students of the National Aerospace University “Kharkiv Aviation Institute”.","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45197354","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}
Oleg Fedorovich, I. Chepkov, M. Lukhanin, Yurii Pronchakov, K. Rybka, Yuliia Leshchenko
The problem of multivariate nature is formed and solved, which is related to the modeling of logistics actions regarding various military equipment and weapons that enter the zone of military conflict. The relevance of the research is related to the comprehensive solution to the problem of the logistical nature of the supply and mastering modern various weapons by the military to create parity of forces in the military conflict zone. The current study creates a complex of logistic methods and models that allow analyzing training of the military, supply of weapons, ammunition and spare parts to the zone of military conflict, for the successful implementation of the goals of the military operation. This article analyzes the problem of using modern and diverse military equipment, which needs to be solved by systematically presenting military training in logistics, supplying various weapons from various manufacturers to the area of combat operations. The optimization model has been created to select and justify the composition of suppliers of weapons, spare parts and ammunition, in the context of risks that arise in the production and transportation of military cargo in a heterogeneous transport network. Optimization is performed in conditions of conflicting criteria: the number of new weapons; time and costs for the production and supply of military equipment; logistical risks. To study dynamic processes in the logistics of supplying weapons, spare parts and ammunition, a model has been created that allows, with the help of simulation agents, the investigation of the paths of movement of military cargo under the conditions of military threats and possible excitation of critical vulnerabilities in the heterogeneous transport supply network. An algorithm for forming the optimal delivery route at the minimum time under risks has been developed. Simulation modeling is used to estimate the movement time of military cargo, delays in supply, accumulation of risks in cargo transportation, consequences of threats and vulnerabilities in supply logistics, etc. This study examines the process of training the military by mastering new competencies for the use of various modern weapons in combat conditions. Simultaneously, the short terms of training of military personnel and the logistics of their transportation to training centers are considered subject to the threats and risks of wartime. The effectiveness of the proposed approach is ensured by a systematic representation of the logistics of supplying various weapons, spare parts and ammunition to the conflict zone, and a comprehensive solution to the research tasks set. The scientific novelty of the conducted research is associated with the development of new methods and models based on system analysis. The following methods were used: simulation modeling, models for optimizing, competence model for acquiring new knowledge by the military personnel. The results of the study should be used to select and justif
{"title":"Modeling of supply logistics and training of military personnel for the successful use of weapons in a combat area","authors":"Oleg Fedorovich, I. Chepkov, M. Lukhanin, Yurii Pronchakov, K. Rybka, Yuliia Leshchenko","doi":"10.32620/reks.2022.3.03","DOIUrl":"https://doi.org/10.32620/reks.2022.3.03","url":null,"abstract":"The problem of multivariate nature is formed and solved, which is related to the modeling of logistics actions regarding various military equipment and weapons that enter the zone of military conflict. The relevance of the research is related to the comprehensive solution to the problem of the logistical nature of the supply and mastering modern various weapons by the military to create parity of forces in the military conflict zone. The current study creates a complex of logistic methods and models that allow analyzing training of the military, supply of weapons, ammunition and spare parts to the zone of military conflict, for the successful implementation of the goals of the military operation. This article analyzes the problem of using modern and diverse military equipment, which needs to be solved by systematically presenting military training in logistics, supplying various weapons from various manufacturers to the area of combat operations. The optimization model has been created to select and justify the composition of suppliers of weapons, spare parts and ammunition, in the context of risks that arise in the production and transportation of military cargo in a heterogeneous transport network. Optimization is performed in conditions of conflicting criteria: the number of new weapons; time and costs for the production and supply of military equipment; logistical risks. To study dynamic processes in the logistics of supplying weapons, spare parts and ammunition, a model has been created that allows, with the help of simulation agents, the investigation of the paths of movement of military cargo under the conditions of military threats and possible excitation of critical vulnerabilities in the heterogeneous transport supply network. An algorithm for forming the optimal delivery route at the minimum time under risks has been developed. Simulation modeling is used to estimate the movement time of military cargo, delays in supply, accumulation of risks in cargo transportation, consequences of threats and vulnerabilities in supply logistics, etc. This study examines the process of training the military by mastering new competencies for the use of various modern weapons in combat conditions. Simultaneously, the short terms of training of military personnel and the logistics of their transportation to training centers are considered subject to the threats and risks of wartime. The effectiveness of the proposed approach is ensured by a systematic representation of the logistics of supplying various weapons, spare parts and ammunition to the conflict zone, and a comprehensive solution to the research tasks set. The scientific novelty of the conducted research is associated with the development of new methods and models based on system analysis. The following methods were used: simulation modeling, models for optimizing, competence model for acquiring new knowledge by the military personnel. The results of the study should be used to select and justif","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44108890","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}
Remote sensing images have found numerous applications nowadays. A traditional outcome or intermediate result of their processing is a classification map. Such maps are usually obtained from a pre-trained classifier and it is desired to have the produced classification maps as accurately as possible. The basic subject of this article is the factors determining this accuracy. The main among them are the quality of remote sensing data and classifier type, parameters and training approach. Image quality can be degraded due to several factors. One of them is distortions introduced by lossy compression that is widely used due to a huge volume of acquired data and the necessity to sufficiently decrease their size at transmission, storage and/or dissemination stages. Because of this, the main goal of this paper is to consider classification and lossy compression jointly. In particular, this means that the classifier learning can be performed for original (uncompressed, compressed in a lossless manner) images (if they are available) as well as for compressed data at hand (offered to a user for classification and further analysis). The task of this paper is to consider and compare these two options. The first one is the classifier learning for original images and further application to compressed data, where images can be compressed with different compression ratios while producing compressed data of different quality. The second option is the use of the classifier learning for compressed images, where compression parameters for training data can be approximately the same as for the images to which the classifier is applied. The main result is that the latter methodology can provide certain benefits compared to the classifier learning for original data if one has to classify compressed remote sensing data. Simulation data are obtained for a classifier based on a convolutional neural network. As images for training and verification, four real-life three-channel (visible range) Sentinel-2 remote sensing images of Kharkiv and Kharkiv region are employed that possess different complexity of the content and have four main classes. The practical recommendations are given. In conclusion, we can state that it is worth having classifiers trained for several degrees of compression and it is reasonable to compress complex structure images with special care.
{"title":"On classifier learning methodologies with application to compressed remote sensing images","authors":"G. Proskura, Oleksii S. Rubel, V. Lukin","doi":"10.32620/reks.2022.3.13","DOIUrl":"https://doi.org/10.32620/reks.2022.3.13","url":null,"abstract":"Remote sensing images have found numerous applications nowadays. A traditional outcome or intermediate result of their processing is a classification map. Such maps are usually obtained from a pre-trained classifier and it is desired to have the produced classification maps as accurately as possible. The basic subject of this article is the factors determining this accuracy. The main among them are the quality of remote sensing data and classifier type, parameters and training approach. Image quality can be degraded due to several factors. One of them is distortions introduced by lossy compression that is widely used due to a huge volume of acquired data and the necessity to sufficiently decrease their size at transmission, storage and/or dissemination stages. Because of this, the main goal of this paper is to consider classification and lossy compression jointly. In particular, this means that the classifier learning can be performed for original (uncompressed, compressed in a lossless manner) images (if they are available) as well as for compressed data at hand (offered to a user for classification and further analysis). The task of this paper is to consider and compare these two options. The first one is the classifier learning for original images and further application to compressed data, where images can be compressed with different compression ratios while producing compressed data of different quality. The second option is the use of the classifier learning for compressed images, where compression parameters for training data can be approximately the same as for the images to which the classifier is applied. The main result is that the latter methodology can provide certain benefits compared to the classifier learning for original data if one has to classify compressed remote sensing data. Simulation data are obtained for a classifier based on a convolutional neural network. As images for training and verification, four real-life three-channel (visible range) Sentinel-2 remote sensing images of Kharkiv and Kharkiv region are employed that possess different complexity of the content and have four main classes. The practical recommendations are given. In conclusion, we can state that it is worth having classifiers trained for several degrees of compression and it is reasonable to compress complex structure images with special care.","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41427761","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}
The subject of study in this work is the land inventory process. The work increases the efficiency of the land inventory process by finding the possibility of reducing the amount of topographic surveying work by algorithmizing and systematizing the information flows with a combination of qualitatively different data. Objectives: to analyze the land inventory process within land management projects to identify possible ways of its efficiency improvement; focusing on information flows, to create an information model for the inventory process; to develop scientific-methodological basis for information support of land management projects to reduce the amount of topographic surveying for implementation into decision support systems for land management. The following results were obtained. The requirements of the current legislation on the inventory of land plots and related tasks are generalized. A set-theoretic model of information flows of the inventory process, which combines the approaches of functional modeling, is proposed. It allows us to combine the qualitatively different data, consider their dynamic nature and the logic of interaction. IDEF3-model developed. This model considers remote sensing data as a source of accurate and up-to-date information, algorithmizes the mechanism of their combination with other information about land plots and explains the dynamic nature of its changes with time. A method for creating a database of the working inventory land plan is proposed. It combines information about land plots from several sources, reduces the amount of topographic surveying by selecting plots that needed to be coordinated (determined) with the geospatial data. The developed scientific-methodological basis of information support for land projects forms the structure of information technology for land inventory. Its usage will reduce the number of resources required for the implementation of land projects, at the same time forming reliable conclusions about the state of the land by using geographic information systems (GIS) and combining dissimilar data. Conclusions. The results of the bibliographic search confirmed the following. The effectiveness of the land inventory process, which ensures compliance with legislation in the field of land management, is very difficult because of the need to analyze a large amount of different information appears, which may contain errors, inconsistent and contradictory data. This requires the development of specialized models and method focused on the use of GIS for their implementation into decision support systems for land management. Scientific-methodological basis of information support for land projects during the inventory of land plots has been developed, practical usage of which confirmed that the time costs for obtaining the land plot research data decreased by almost 33% and the accuracy of measuring geometric dimensions of the land plot increased by about 1%.
{"title":"Formalizing the land inventory process for information support of land projects management","authors":"S. Danshyna, Valeriy Cheranovskiy","doi":"10.32620/reks.2022.3.01","DOIUrl":"https://doi.org/10.32620/reks.2022.3.01","url":null,"abstract":"The subject of study in this work is the land inventory process. The work increases the efficiency of the land inventory process by finding the possibility of reducing the amount of topographic surveying work by algorithmizing and systematizing the information flows with a combination of qualitatively different data. Objectives: to analyze the land inventory process within land management projects to identify possible ways of its efficiency improvement; focusing on information flows, to create an information model for the inventory process; to develop scientific-methodological basis for information support of land management projects to reduce the amount of topographic surveying for implementation into decision support systems for land management. The following results were obtained. The requirements of the current legislation on the inventory of land plots and related tasks are generalized. A set-theoretic model of information flows of the inventory process, which combines the approaches of functional modeling, is proposed. It allows us to combine the qualitatively different data, consider their dynamic nature and the logic of interaction. IDEF3-model developed. This model considers remote sensing data as a source of accurate and up-to-date information, algorithmizes the mechanism of their combination with other information about land plots and explains the dynamic nature of its changes with time. A method for creating a database of the working inventory land plan is proposed. It combines information about land plots from several sources, reduces the amount of topographic surveying by selecting plots that needed to be coordinated (determined) with the geospatial data. The developed scientific-methodological basis of information support for land projects forms the structure of information technology for land inventory. Its usage will reduce the number of resources required for the implementation of land projects, at the same time forming reliable conclusions about the state of the land by using geographic information systems (GIS) and combining dissimilar data. Conclusions. The results of the bibliographic search confirmed the following. The effectiveness of the land inventory process, which ensures compliance with legislation in the field of land management, is very difficult because of the need to analyze a large amount of different information appears, which may contain errors, inconsistent and contradictory data. This requires the development of specialized models and method focused on the use of GIS for their implementation into decision support systems for land management. Scientific-methodological basis of information support for land projects during the inventory of land plots has been developed, practical usage of which confirmed that the time costs for obtaining the land plot research data decreased by almost 33% and the accuracy of measuring geometric dimensions of the land plot increased by about 1%.","PeriodicalId":36122,"journal":{"name":"Radioelectronic and Computer Systems","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44970449","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}
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