Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.05
O. Lazorenko, A. A. Onishchenko, L. Chernogor
One of the topical directions of modern fractal radio physics is the multifractal analysis of signals and processes of various origins. A set of deterministic and stochastic models of monofractal and multifractal signals and processes in the time domain is proposed. New multifractal signal characteristics, namely, the coefficient of asymmetry of the multifractal spectrum function, the relative width of the multifractal spectrum and the dimension of the multifractal support, are introduced, the necessity of their use is demonstrated on examples. Using Wavelet Transform Modulus Maxima Method and Multi-Fractal Detrended Fluctuation Analysis Method, a detailed multifractal analysis of model signals is performed. The features of multifractal analysis of monofractal, multifractal and non-fractal signals are established, the appropriate recommendations for practitioners are formulated. Convenient formats for presenting analysis results have been developed. It was found that during the transition of the multifractal signal to the monofractal regime, the function of the multifractal spectrum of the physical fractal does not collapse into a point, as it should happen in theory for a mathematical fractal. Threshold values of multifractal characteristics, which are indicators of the appearance of the monofractal, are proposed. It has been shown that multifractal analysis of non-fractal signals leads to the appearance of multifractal spectra with anomalous values of multifractal characteristics. The correction function method is modified for the methods of multifractal analysis of signals and processes. It is proved that its usage makes it possible to reduce the deviation of the obtained estimate of the generalized Hurst exponent from the true known value of the Hölder exponent of the analyzed signal from 5 – 90% to 3 – 8%.
{"title":"Multifractal analysis of model fractal and multifractal signals","authors":"O. Lazorenko, A. A. Onishchenko, L. Chernogor","doi":"10.30837/rt.2022.4.211.05","DOIUrl":"https://doi.org/10.30837/rt.2022.4.211.05","url":null,"abstract":"One of the topical directions of modern fractal radio physics is the multifractal analysis of signals and processes of various origins. A set of deterministic and stochastic models of monofractal and multifractal signals and processes in the time domain is proposed. New multifractal signal characteristics, namely, the coefficient of asymmetry of the multifractal spectrum function, the relative width of the multifractal spectrum and the dimension of the multifractal support, are introduced, the necessity of their use is demonstrated on examples. Using Wavelet Transform Modulus Maxima Method and Multi-Fractal Detrended Fluctuation Analysis Method, a detailed multifractal analysis of model signals is performed. The features of multifractal analysis of monofractal, multifractal and non-fractal signals are established, the appropriate recommendations for practitioners are formulated. Convenient formats for presenting analysis results have been developed. It was found that during the transition of the multifractal signal to the monofractal regime, the function of the multifractal spectrum of the physical fractal does not collapse into a point, as it should happen in theory for a mathematical fractal. Threshold values of multifractal characteristics, which are indicators of the appearance of the monofractal, are proposed. It has been shown that multifractal analysis of non-fractal signals leads to the appearance of multifractal spectra with anomalous values of multifractal characteristics. The correction function method is modified for the methods of multifractal analysis of signals and processes. It is proved that its usage makes it possible to reduce the deviation of the obtained estimate of the generalized Hurst exponent from the true known value of the Hölder exponent of the analyzed signal from 5 – 90% to 3 – 8%.","PeriodicalId":41675,"journal":{"name":"Visnyk NTUU KPI Seriia-Radiotekhnika Radioaparatobuduvannia","volume":"39 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89395942","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}
Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.08
I. Svyd, M. Tkach, I. Obod
The paper examines the existing systems of radar identification based on the "friend-foe" feature from the point of view of immunity evaluation. Currently, there are two systems of the radar identification based on the characteristic of "friend-foe", namely, the "Password" and MkXIIA. They are the radar identification systems based on the "home-foreign" feature. The former of the specified systems operates in a frequency range that differs from the frequency range of secondary radar systems, while the second one operates in the frequency range of secondary radar. These systems are ones of the main information resources of the airspace control system and are built on the principles of a one-channel or two-channel information transmission system. It allows the interested party, both an unauthorized use of this information resource for remote determination of the coordinates of aerial objects, on the one hand, and twisting the information of these information resources, on the other hand, which leads to unpredictable results. The purpose of the work is to assess the immunity of existing radar identification systems based on the "friend-foe" feature. The analysis of the interference protection of existing systems for the object radar identification based on the "friend-foe" feature, built on the principles of interrogative and non-interrogative information systems presented in this work, showed that the use of rectangular radio signals with time-pulse modulation as request and response signals emitting by air objects, has low immunity and excludes the energy stealthiest of the respondents of aerial objects. And, as a result, it allows for unauthorized calculation of the coordinates of air objects by the interested party based on the emitted identification signals on the basis of "friend-foe".
{"title":"Comparative analysis of interference protection of \"Friend-Foe\" radar identification systems","authors":"I. Svyd, M. Tkach, I. Obod","doi":"10.30837/rt.2022.4.211.08","DOIUrl":"https://doi.org/10.30837/rt.2022.4.211.08","url":null,"abstract":"The paper examines the existing systems of radar identification based on the \"friend-foe\" feature from the point of view of immunity evaluation. Currently, there are two systems of the radar identification based on the characteristic of \"friend-foe\", namely, the \"Password\" and MkXIIA. They are the radar identification systems based on the \"home-foreign\" feature. The former of the specified systems operates in a frequency range that differs from the frequency range of secondary radar systems, while the second one operates in the frequency range of secondary radar. These systems are ones of the main information resources of the airspace control system and are built on the principles of a one-channel or two-channel information transmission system. It allows the interested party, both an unauthorized use of this information resource for remote determination of the coordinates of aerial objects, on the one hand, and twisting the information of these information resources, on the other hand, which leads to unpredictable results. The purpose of the work is to assess the immunity of existing radar identification systems based on the \"friend-foe\" feature. The analysis of the interference protection of existing systems for the object radar identification based on the \"friend-foe\" feature, built on the principles of interrogative and non-interrogative information systems presented in this work, showed that the use of rectangular radio signals with time-pulse modulation as request and response signals emitting by air objects, has low immunity and excludes the energy stealthiest of the respondents of aerial objects. And, as a result, it allows for unauthorized calculation of the coordinates of air objects by the interested party based on the emitted identification signals on the basis of \"friend-foe\".","PeriodicalId":41675,"journal":{"name":"Visnyk NTUU KPI Seriia-Radiotekhnika Radioaparatobuduvannia","volume":"1 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89932662","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}
Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.10
V. Borshchov, O. Listratenko, M. Protsenko, I. Tymchuk, O. Kravchenko, O.V. Suddia, I.V. Borshchov, M. Slipchenko
Issues of direct modeling effective thermal conductivity of two-component thermally conductive polyimide composite films based on polyimide thermosetting varnishes and thermally conductive powder fillers are considered. 3D-structural modeling of elementary cubic cells of polyimide composites has been performed. Calculations of average heat fluxes and effective thermal conductivity of variants of polyimide composite films with the introduction of highly thermally conductive highly dispersed and ultradispersed powder fillers into the polyimide matrix were carried out, including those from SiO2, SiC, Al2O3, AlN, taking into account boundary and initial conditions using COMSOL MULTIPHYSICS software. Specific recommendations are proposed for direct modeling of the thermal conductivity of environments with a complex structure and for carrying out with sufficient reliability numerical calculations of the effective thermal conductivity of polyimide composite films in order to increase their thermal conductivity from 0,12 W/(m•K) up to 1-4 W/(m•K) by changing concentration and thermal conductivity of mixtures of filler particles of micron and ultramicron sizes.
{"title":"Structural modeling and calculation of thermal conductivity of polyimide composite materials","authors":"V. Borshchov, O. Listratenko, M. Protsenko, I. Tymchuk, O. Kravchenko, O.V. Suddia, I.V. Borshchov, M. Slipchenko","doi":"10.30837/rt.2022.4.211.10","DOIUrl":"https://doi.org/10.30837/rt.2022.4.211.10","url":null,"abstract":"Issues of direct modeling effective thermal conductivity of two-component thermally conductive polyimide composite films based on polyimide thermosetting varnishes and thermally conductive powder fillers are considered. \u00003D-structural modeling of elementary cubic cells of polyimide composites has been performed. \u0000Calculations of average heat fluxes and effective thermal conductivity of variants of polyimide composite films with the introduction of highly thermally conductive highly dispersed and ultradispersed powder fillers into the polyimide matrix were carried out, including those from SiO2, SiC, Al2O3, AlN, taking into account boundary and initial conditions using COMSOL MULTIPHYSICS software. \u0000Specific recommendations are proposed for direct modeling of the thermal conductivity of environments with a complex structure and for carrying out with sufficient reliability numerical calculations of the effective thermal conductivity of polyimide composite films in order to increase their thermal conductivity from 0,12 W/(m•K) up to 1-4 W/(m•K) by changing concentration and thermal conductivity of mixtures of filler particles of micron and ultramicron sizes.","PeriodicalId":41675,"journal":{"name":"Visnyk NTUU KPI Seriia-Radiotekhnika Radioaparatobuduvannia","volume":"44 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74142221","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}
Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.06
V. Kartashov, V.A. Pososhenko, A. Kapusta, M. Rybnykov, E.V. Pershin
The current trend towards increasing the efficiency of UAV use is the transition from their single use to group use. In accordance with this, when building a complex integrated system for detecting and monitoring UAVs, including various information channels, it is advisable to take into account the features of the system functioning associated with the detection of groups of UAVs. The article discusses the information, energy and search capabilities of individual detection tools being a part of the integrated UAV surveillance system in order to build an effective algorithm for joint processing of incoming input signals, taking into account various capabilities of individual channels (in terms of range, recognition, etc.). An optimal algorithm for detecting groups of UAVs in a complex integrated system combining detection decisions made in private channels is synthesized. According to the synthesized algorithm, complex processing consists in summing up the solutions of individual detectors with some weights determined by the quality of the decisions made in the channels. The quality of solutions, in turn, depends on the technical means used in the channels and the conditions of observation. A sequence for solving a set of interrelated tasks in a complex integrated UAV surveillance system as the group target approaches the protected object is proposed. The sequence includes the following operations: identification of a group target (energy detection); estimation of coordinates of a group of objects; spatial resolution and determination of the number of vehicles in a group; recognition (type determination) of each individual device; assessment of the coordinates of each aircraft separately; determination of the composition of the group (homogeneous, heterogeneous); determination of the specialization of the group and revealing the nature of its tasks.
{"title":"Features of the tasks of identifying and observing groups of unmanned letter vehicles","authors":"V. Kartashov, V.A. Pososhenko, A. Kapusta, M. Rybnykov, E.V. Pershin","doi":"10.30837/rt.2022.4.211.06","DOIUrl":"https://doi.org/10.30837/rt.2022.4.211.06","url":null,"abstract":"The current trend towards increasing the efficiency of UAV use is the transition from their single use to group use. In accordance with this, when building a complex integrated system for detecting and monitoring UAVs, including various information channels, it is advisable to take into account the features of the system functioning associated with the detection of groups of UAVs. \u0000The article discusses the information, energy and search capabilities of individual detection tools being a part of the integrated UAV surveillance system in order to build an effective algorithm for joint processing of incoming input signals, taking into account various capabilities of individual channels (in terms of range, recognition, etc.). \u0000An optimal algorithm for detecting groups of UAVs in a complex integrated system combining detection decisions made in private channels is synthesized. According to the synthesized algorithm, complex processing consists in summing up the solutions of individual detectors with some weights determined by the quality of the decisions made in the channels. The quality of solutions, in turn, depends on the technical means used in the channels and the conditions of observation. \u0000A sequence for solving a set of interrelated tasks in a complex integrated UAV surveillance system as the group target approaches the protected object is proposed. The sequence includes the following operations: identification of a group target (energy detection); estimation of coordinates of a group of objects; spatial resolution and determination of the number of vehicles in a group; recognition (type determination) of each individual device; assessment of the coordinates of each aircraft separately; determination of the composition of the group (homogeneous, heterogeneous); determination of the specialization of the group and revealing the nature of its tasks.","PeriodicalId":41675,"journal":{"name":"Visnyk NTUU KPI Seriia-Radiotekhnika Radioaparatobuduvannia","volume":"134 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77378233","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}
Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.02
S.O. Kandiy
The paper provides a proof in the IND-CCA2 random oracle model of the security of the asymmetric encryption scheme described in the DSTU 8961:2019 standard, and the IND-CCA2 security of the corresponding key encapsulation mechanism. Since the standard contains only a technical description of transformations, a formalized mathematical model was introduced in Chapter 4 without unnecessary technical details that do not affect safety assessments. Since the system-wide parameters in the standard were chosen in such a way that the scheme did not contain decryption errors, it was possible to simplify significantly the proof. Section 5 provides a schematic overview of possible attack vectors on the DSTU 8961:2019, but a detailed analysis is the subject of further research. In addition to safety, the analysis also showed that the DSTU 8961:2019 has a certain disadvantage in terms of safety. The design can be significantly simplified and accelerated without loss of safety. Security, on the contrary, can be significantly increased.
{"title":"Analysis of DSTU 8961:2019 in random oracle model","authors":"S.O. Kandiy","doi":"10.30837/rt.2022.4.211.02","DOIUrl":"https://doi.org/10.30837/rt.2022.4.211.02","url":null,"abstract":"The paper provides a proof in the IND-CCA2 random oracle model of the security of the asymmetric encryption scheme described in the DSTU 8961:2019 standard, and the IND-CCA2 security of the corresponding key encapsulation mechanism. Since the standard contains only a technical description of transformations, a formalized mathematical model was introduced in Chapter 4 without unnecessary technical details that do not affect safety assessments. Since the system-wide parameters in the standard were chosen in such a way that the scheme did not contain decryption errors, it was possible to simplify significantly the proof. Section 5 provides a schematic overview of possible attack vectors on the DSTU 8961:2019, but a detailed analysis is the subject of further research. In addition to safety, the analysis also showed that the DSTU 8961:2019 has a certain disadvantage in terms of safety. The design can be significantly simplified and accelerated without loss of safety. Security, on the contrary, can be significantly increased.","PeriodicalId":41675,"journal":{"name":"Visnyk NTUU KPI Seriia-Radiotekhnika Radioaparatobuduvannia","volume":"122 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78442239","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}
Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.11
V. Rapin
A preliminary analysis of published works on this topic showed that at present there is no sufficiently substantiated theory of such devices, and the approximate approaches used are rough and do not always meet the requirements of practice. The proposed transition from a differential self-oscillator to an equivalent single-circuit oscillator has not received a convincing justification. This article presents a methodology for studying a synchronized differential oscillator using rigorous methods. A mathematical model of such oscillator is presented in the form of nonlinear differential equations obtained on the basis of Kirchhoff's laws. Their analysis made it possible to substantiate the transition to the model of a single circuit LC oscillator, equivalent to a differential one. A technique for such a transition is proposed, including the procedure for determining the nonlinear characteristics of the amplifying element of this self-oscillator, based on the nonlinear characteristics of two amplifying elements of the differential oscillator. The mathematical model of an equivalent oscillator is represented by a non-linear differential Van der Pol equation in a dimensionless form, it is simple and accurate. This form of representation made it possible to single out a small parameter and estimate its value. In the case of small values of the small parameter, as is known, traditional methods can be used for its analysis. Thus, the task of studying the synchronization process of a differential oscillator is reduced to the study of the synchronization process of a Van der Pol oscillator. The presented results can be useful in the development of various devices based on synchronized differential oscillators.
{"title":"Theoretical investigation of injection-locked differential oscillator","authors":"V. Rapin","doi":"10.30837/rt.2022.4.211.11","DOIUrl":"https://doi.org/10.30837/rt.2022.4.211.11","url":null,"abstract":"A preliminary analysis of published works on this topic showed that at present there is no sufficiently substantiated theory of such devices, and the approximate approaches used are rough and do not always meet the requirements of practice. The proposed transition from a differential self-oscillator to an equivalent single-circuit oscillator has not received a convincing justification. \u0000This article presents a methodology for studying a synchronized differential oscillator using rigorous methods. A mathematical model of such oscillator is presented in the form of nonlinear differential equations obtained on the basis of Kirchhoff's laws. Their analysis made it possible to substantiate the transition to the model of a single circuit LC oscillator, equivalent to a differential one. A technique for such a transition is proposed, including the procedure for determining the nonlinear characteristics of the amplifying element of this self-oscillator, based on the nonlinear characteristics of two amplifying elements of the differential oscillator. \u0000The mathematical model of an equivalent oscillator is represented by a non-linear differential Van der Pol equation in a dimensionless form, it is simple and accurate. This form of representation made it possible to single out a small parameter and estimate its value. In the case of small values of the small parameter, as is known, traditional methods can be used for its analysis. Thus, the task of studying the synchronization process of a differential oscillator is reduced to the study of the synchronization process of a Van der Pol oscillator. The presented results can be useful in the development of various devices based on synchronized differential oscillators.","PeriodicalId":41675,"journal":{"name":"Visnyk NTUU KPI Seriia-Radiotekhnika Radioaparatobuduvannia","volume":"11 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82901677","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}
Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.03
V. Yesin, V. Vilihura
In the modern world, the problem of working with big data and workloads is becoming more and more acute. For more than forty years, relational databases have been the main leading systems for storing, searching and managing data. However, despite their great popularity, application experience and universality, traditional relational DBMS, due to the growing needs for scalability and performance, often cannot meet modern requirements. This has led to the emergence of new alternative data management systems, including NewSQL systems. NewSQL is a class of modern relational database management systems that provide performance comparable to NoSQL systems while maintaining the data consistency guarantees inherent in traditional database systems. The growing interest in NewSQL technology in recent times has led to an increase number of evaluations and comparisons among competing NewSQL technologies. However, today there is still a certain lack of work devoted to the study of the features of NewSQL solutions and their capabilities in comparison with other technologies. This paper discusses the main features of the most famous NewSQL products of different categories and the identified problems associated with them. To overcome the certain ambiguity in the names and translations of some terms related to the subject area under consideration, which takes place in numerous relevant sources, additional explanations are given. For comparison, the paper presents the values of important characteristics inherent in NewSQL, traditional relational and NoSQL database systems. This paper can help researchers and people from the industry choose the best storage solutions for their needs.
{"title":"The main categories of NewSQL databases and their features","authors":"V. Yesin, V. Vilihura","doi":"10.30837/rt.2022.4.211.03","DOIUrl":"https://doi.org/10.30837/rt.2022.4.211.03","url":null,"abstract":"In the modern world, the problem of working with big data and workloads is becoming more and more acute. For more than forty years, relational databases have been the main leading systems for storing, searching and managing data. However, despite their great popularity, application experience and universality, traditional relational DBMS, due to the growing needs for scalability and performance, often cannot meet modern requirements. This has led to the emergence of new alternative data management systems, including NewSQL systems. NewSQL is a class of modern relational database management systems that provide performance comparable to NoSQL systems while maintaining the data consistency guarantees inherent in traditional database systems. The growing interest in NewSQL technology in recent times has led to an increase number of evaluations and comparisons among competing NewSQL technologies. However, today there is still a certain lack of work devoted to the study of the features of NewSQL solutions and their capabilities in comparison with other technologies. This paper discusses the main features of the most famous NewSQL products of different categories and the identified problems associated with them. To overcome the certain ambiguity in the names and translations of some terms related to the subject area under consideration, which takes place in numerous relevant sources, additional explanations are given. For comparison, the paper presents the values of important characteristics inherent in NewSQL, traditional relational and NoSQL database systems. This paper can help researchers and people from the industry choose the best storage solutions for their needs.","PeriodicalId":41675,"journal":{"name":"Visnyk NTUU KPI Seriia-Radiotekhnika Radioaparatobuduvannia","volume":"34 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86540729","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}
Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.07
V. Kartashov, V.A. Pososhenko, K.V. Kolesnik, V. Kolesnik, R.I. Bobnev, A. Kapusta
The task of estimating the energy distribution over the observation interval of radar signals scattered on atmospheric inhomogeneities, arising as a result of UAV operation, is considered. The solution to this problem is necessary to improve detection algorithms, to classify the detected UAVs according to additional informational features, to improve the resolution when detecting several devices located at the same range during the group application of UAVs, to clarify the time parameters of the evolution of the movement of UAVs in time and space. A similar problem arises due to the need to process useful radar signals with a low signal-to-noise ratio in order to achieve the maximum possible range of reliable UAV detection. Because of this, it becomes impossible to estimate directly the energy of useful signals by the method of comparison with reference physical quantities due to a large measurement error. Therefore, an evaluation algorithm is proposed, based on the methods of the theory of ordinal statistics, which provide, instead of comparing numerical realizations with a certain standard, to form a variational series from them under the condition of a priori knowledge of the distribution function of these realizations. At the same time, the fact is used that for certain distributions of a random variable, among which there are normal and all limited ones, the variance of the estimate in the form of a mathematical expectation of certain ordinal statistics is significantly less than the variance of a direct measurement at a low signal-to-noise ratio. In order to save time and computing resources during real-time processing of received signals, it is proposed to use pre-calculated arrays of numerical values of mathematical expectation and dispersion of ordinal statistics for various parameters of the density distribution of a random variable.
{"title":"Algorithm for estimating the energy distribution of radar signals scattering on acoustic disturbances created by UAVs","authors":"V. Kartashov, V.A. Pososhenko, K.V. Kolesnik, V. Kolesnik, R.I. Bobnev, A. Kapusta","doi":"10.30837/rt.2022.4.211.07","DOIUrl":"https://doi.org/10.30837/rt.2022.4.211.07","url":null,"abstract":"The task of estimating the energy distribution over the observation interval of radar signals scattered on atmospheric inhomogeneities, arising as a result of UAV operation, is considered. The solution to this problem is necessary to improve detection algorithms, to classify the detected UAVs according to additional informational features, to improve the resolution when detecting several devices located at the same range during the group application of UAVs, to clarify the time parameters of the evolution of the movement of UAVs in time and space. A similar problem arises due to the need to process useful radar signals with a low signal-to-noise ratio in order to achieve the maximum possible range of reliable UAV detection. Because of this, it becomes impossible to estimate directly the energy of useful signals by the method of comparison with reference physical quantities due to a large measurement error. Therefore, an evaluation algorithm is proposed, based on the methods of the theory of ordinal statistics, which provide, instead of comparing numerical realizations with a certain standard, to form a variational series from them under the condition of a priori knowledge of the distribution function of these realizations. At the same time, the fact is used that for certain distributions of a random variable, among which there are normal and all limited ones, the variance of the estimate in the form of a mathematical expectation of certain ordinal statistics is significantly less than the variance of a direct measurement at a low signal-to-noise ratio. In order to save time and computing resources during real-time processing of received signals, it is proposed to use pre-calculated arrays of numerical values of mathematical expectation and dispersion of ordinal statistics for various parameters of the density distribution of a random variable.","PeriodicalId":41675,"journal":{"name":"Visnyk NTUU KPI Seriia-Radiotekhnika Radioaparatobuduvannia","volume":"22 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80200341","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}
Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.12
O.I. Dovnar, M. Babakov, V.I. Cherkis
Since the beginning of hostilities, medical institutions have suffered from cyber attacks, the number of which is not decreasing. The load on the servers even before the start of the war was already quite significant. Since Ukraine suffered severe restrictions due to Covid-19, in part, most institutions were transferred to global medical databases, but with a serious breakthrough, digital capacities did not have time to grow. Even small cyber attacks in the medical field can be critical, so it is necessary to identify accurately medical personnel for access and implement a special application, which will not allow other people to get it, this makes it possible to block immediately all other requests without processing, and this is one of the ways to optimize and increasing security. The task can be solved by standard means of authorization, but they are quite easy to bypass, ordinary software can also be reprogrammed, identification by phone number can be too expensive, so a combined method is proposed: special equipment for reading fingerprints and the corresponding software application. This method is sufficiently reliable and simple to implement (medical personnel will only need to put their finger to the sensor), as well as economical and not demanding. The developed prototype for authorization on the Arduino hardware platform provides the necessary functionality and meets the task. The sensor recognizes more than 100 people, and the convenient mini USB allows you to connect conveniently the device to any computer port. A special algorithm will block the device in case of intervention by a person who does not have access to the corresponding resource. Can be easily reprogrammed and configured to the required equipment, and the case can be printed according to the necessary requirements.
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Pub Date : 2022-12-30DOI: 10.30837/rt.2022.4.211.09
V. Alieksieiev, D. Gretskih, D. S. Gavva, V. Lykhograi
The article consists of three parts. The analysis of existing technologies of wireless power transfer (WPT) is carried out in the first part. It is noted that one of the factors that determines the choice of one or another WPT technology is the distance over which the power is transmitted and the type of electromagnetic (EM) energy used. The essence of WPT technologies in the near zone, Fresnel zone and Fraunhofer zone is explained. A generalized block diagram of the WPT system is presented. Areas of application and trends in the further development of the WPT technologies over short distances using induction and resonance methods, the WPT technologies over long distances, the technology of EM energy harvesting from the surrounding space and its conversion into direct current for powering low-power devices are considered. The achievements of the team of the antenna laboratory of the Kharkiv National University of Radio Electronics (KhNURE) in the area of WPT are presented in the second part of the article. Namely, the electrodynamics’ approach is considered which is based on a single idea about the functioning of WPT systems and which include antennas and their circuits and ways of excitation with nonlinear elements. The stages of building a nonlinear mathematical model (MM) of the electrodynamics’ level of the WPT system are presented, according to which the entire WPT system, which generally includes the transmitting subsystem and the receiving subsystem, is considered as a single multi-input antenna system with nonlinear characteristics. The proposed MM provides a complete representation of the WPT systems operation of a wide class and purpose, in which fundamentally different WPT technologies are used. The third part of the article presents new results related to continued research. The analysis of the adequacy of the developed MM of WPT system is carried out. The results of simulation of WPT systems with the induction method of energy transfer (near zone) and their comparison with theoretical and experimental data of other authors showed the reliability and universality of the proposed approach and the MM of WPT system developed on its basis.
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