Pub Date : 2019-10-04DOI: 10.31799/1684-8853-2019-4-69-81
A. Gorbunova, E. Medvedeva, Yuliya Gaidamaka Yu. V., V. Shorgin, K. Samouylov
Introduction: One of the main advantages of multiple antenna systems is the support of multi-user connections, simultaneouslytransmitting parallel data streams. This can significantly increase the overall system throughput. However, the spectral efficiency can be additionally increased through the usage of various dynamic strategies which take into account the current state of the system.Here we propose a method to evaluate the effectiveness of such strategies with the help of appropriate mathematical models. Purpose:Development of mathematical models for a multi-user MIMO system which would allow you to evaluate the average delay of a filetransfer. Results: Mathematical models of the MIMO system are presented in the form of discrete/continuous time queuing systemsfor three user service strategies. We provide formulas for estimating the average file transfer delay in a closed form, which simplifynumerical analysis as compared to the well-known methods using mathematical models in continuous time. This method allows you tofind the most effective strategy with less computational complexity. Another advantage of the constructed models is the opportunityof further research on the effect of file length distributions on the file transfer delay. The conclusions we made about the effectivenessof each strategy are consistent with our earlier work, which is confirmed by a numerical example. Practical relevance: The developedmathematical models for a multi-user MIMO system can be used to set the operating parameters of a real wireless MIMO system.
{"title":"Effective user service strategies in a multi-user MIMO system","authors":"A. Gorbunova, E. Medvedeva, Yuliya Gaidamaka Yu. V., V. Shorgin, K. Samouylov","doi":"10.31799/1684-8853-2019-4-69-81","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-4-69-81","url":null,"abstract":"Introduction: One of the main advantages of multiple antenna systems is the support of multi-user connections, simultaneouslytransmitting parallel data streams. This can significantly increase the overall system throughput. However, the spectral efficiency can be additionally increased through the usage of various dynamic strategies which take into account the current state of the system.Here we propose a method to evaluate the effectiveness of such strategies with the help of appropriate mathematical models. Purpose:Development of mathematical models for a multi-user MIMO system which would allow you to evaluate the average delay of a filetransfer. Results: Mathematical models of the MIMO system are presented in the form of discrete/continuous time queuing systemsfor three user service strategies. We provide formulas for estimating the average file transfer delay in a closed form, which simplifynumerical analysis as compared to the well-known methods using mathematical models in continuous time. This method allows you tofind the most effective strategy with less computational complexity. Another advantage of the constructed models is the opportunityof further research on the effect of file length distributions on the file transfer delay. The conclusions we made about the effectivenessof each strategy are consistent with our earlier work, which is confirmed by a numerical example. Practical relevance: The developedmathematical models for a multi-user MIMO system can be used to set the operating parameters of a real wireless MIMO system.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47824302","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 : 2019-10-04DOI: 10.31799/1684-8853-2019-4-62-68
Sergey Dvornikov, Sergey Dvornikov, A. Pshenichnikov
Introduction: When the radio frequency spectrum is as busy as it is today, it is especially important to ensure effective functioningof radio systems under various signal and interfering conditions. One of the research fields is radio frequency resource management.Purpose: Developing a system of proposals for choosing a frequency resource for radio system operation in the mode of frequencyhoppingspread spectrum (FHSS). Results: On the basis of the developed analytical apparatus, we have specified the conditions forpreliminary testing of working frequencies in the direct response mode in FHSS radio channels. Practical conditions are substantiatedfor achieving the required performance indicators from the parameters of the preliminary frequency testing process. A statementis proved that determines how the improvement of timely message delivery in a radio link with a pseudo-random adjustment of theoperating frequency depends on the growth of the array of allocated frequencies and on the speed of the program adjustment. A featureof the newly developed theoretical approaches is the formalization of radio system performance indicators based on the ratio of the timewithout taking into account the preliminary testing processes to the time required to implement the test mode with a fixed amount of aninformation message. The chosen criterion for selecting a frequency group is the permissible level of errors in the received test sequencewhose evaluation determines the group of specified unsuitable frequencies. On the basis of the conducted simulation, we have revealedthe relationships between the number of unsuitable frequencies and the gains provided by the timeliness of information transfer,depending on the performance indicators found during the testing of the working frequencies. Practical relevance: The developedsolutions, in their entirety, provide a better timeliness of message delivery in radio systems in FHSS mode.
{"title":"Analysis of frequency resource for FHSS mode","authors":"Sergey Dvornikov, Sergey Dvornikov, A. Pshenichnikov","doi":"10.31799/1684-8853-2019-4-62-68","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-4-62-68","url":null,"abstract":"Introduction: When the radio frequency spectrum is as busy as it is today, it is especially important to ensure effective functioningof radio systems under various signal and interfering conditions. One of the research fields is radio frequency resource management.Purpose: Developing a system of proposals for choosing a frequency resource for radio system operation in the mode of frequencyhoppingspread spectrum (FHSS). Results: On the basis of the developed analytical apparatus, we have specified the conditions forpreliminary testing of working frequencies in the direct response mode in FHSS radio channels. Practical conditions are substantiatedfor achieving the required performance indicators from the parameters of the preliminary frequency testing process. A statementis proved that determines how the improvement of timely message delivery in a radio link with a pseudo-random adjustment of theoperating frequency depends on the growth of the array of allocated frequencies and on the speed of the program adjustment. A featureof the newly developed theoretical approaches is the formalization of radio system performance indicators based on the ratio of the timewithout taking into account the preliminary testing processes to the time required to implement the test mode with a fixed amount of aninformation message. The chosen criterion for selecting a frequency group is the permissible level of errors in the received test sequencewhose evaluation determines the group of specified unsuitable frequencies. On the basis of the conducted simulation, we have revealedthe relationships between the number of unsuitable frequencies and the gains provided by the timeliness of information transfer,depending on the performance indicators found during the testing of the working frequencies. Practical relevance: The developedsolutions, in their entirety, provide a better timeliness of message delivery in radio systems in FHSS mode.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45999114","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 : 2019-10-04DOI: 10.31799/1684-8853-2019-4-54-61
V. I. Ponomarenko, Elena Navrotskaya, Danil Kul’minskii, Mikhail D. Prokhorov
Introduction: Communication systems based on the use of dynamical chaos have a number of positive features. Dynamical chaoshas the properties of random processes, which allows systems based on it to ensure the information transmission confidentiality.However, a quantitative security assessment of such systems is a complicated problem, since the methods for evaluating cryptographicstrength are well developed only for the classical encryption algorithms. Purpose: Development of a method for quantitative estimationof confidentiality of a binary signal hidden transmission in a communication system based on a chaotic time-delay oscillator withswitchable delay time. Results: A method is proposed for estimating the confidentiality of a binary information signal transmissionin a communication system using a chaotic time-delay oscillator with switchable delay time as a transmitter. The method is based onestimating the power of the key space for the chaotic communication system under study. We have considered the cases when sometransmitter parameters are known, and the most general case when all the transmitter parameters are unknown. A communicationsystem based on dynamical chaos may have a much higher confidentiality than the classical cryptographic algorithm using a cipher witha key length of 56 bits, but is significantly inferior in terms of cryptographic strength to a cipher with a key length of 128 bits. Practicalrelevance: The proposed method allows us to obtain a quantitative estimation of confidentiality of communication systems based ondynamical chaos, and compare it with the known strength of classical cryptographic algorithms.
{"title":"ОЦЕНКА КОНФИДЕНЦИАЛЬНОСТИ СИСТЕМЫ ПЕРЕДАЧИ ИНФОРМАЦИИ НА ОСНОВЕ ХАОТИЧЕСКОГО ГЕНЕРАТОРА С ЗАПАЗДЫВАНИЕМ И ПЕРЕКЛЮЧАЕМЫМ ВРЕМЕНЕМ ЗАДЕРЖКИ","authors":"V. I. Ponomarenko, Elena Navrotskaya, Danil Kul’minskii, Mikhail D. Prokhorov","doi":"10.31799/1684-8853-2019-4-54-61","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-4-54-61","url":null,"abstract":"Introduction: Communication systems based on the use of dynamical chaos have a number of positive features. Dynamical chaoshas the properties of random processes, which allows systems based on it to ensure the information transmission confidentiality.However, a quantitative security assessment of such systems is a complicated problem, since the methods for evaluating cryptographicstrength are well developed only for the classical encryption algorithms. Purpose: Development of a method for quantitative estimationof confidentiality of a binary signal hidden transmission in a communication system based on a chaotic time-delay oscillator withswitchable delay time. Results: A method is proposed for estimating the confidentiality of a binary information signal transmissionin a communication system using a chaotic time-delay oscillator with switchable delay time as a transmitter. The method is based onestimating the power of the key space for the chaotic communication system under study. We have considered the cases when sometransmitter parameters are known, and the most general case when all the transmitter parameters are unknown. A communicationsystem based on dynamical chaos may have a much higher confidentiality than the classical cryptographic algorithm using a cipher witha key length of 56 bits, but is significantly inferior in terms of cryptographic strength to a cipher with a key length of 128 bits. Practicalrelevance: The proposed method allows us to obtain a quantitative estimation of confidentiality of communication systems based ondynamical chaos, and compare it with the known strength of classical cryptographic algorithms.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":"14 1","pages":"54-61"},"PeriodicalIF":0.0,"publicationDate":"2019-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69413320","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 : 2019-10-04DOI: 10.31799/1684-8853-2019-4-45-53
Nikita Markovnikov, I. Kipyatkova
Problem: Classical systems of automatic speech recognition are traditionally built using an acoustic model based on hidden Markovmodels and a statistical language model. Such systems demonstrate high recognition accuracy, but consist of several independentcomplex parts, which can cause problems when building models. Recently, an end-to-end recognition method has been spread, usingdeep artificial neural networks. This approach makes it easy to implement models using just one neural network. End-to-end modelsoften demonstrate better performance in terms of speed and accuracy of speech recognition. Purpose: Implementation of end-toendmodels for the recognition of continuous Russian speech, their adjustment and comparison with hybrid base models in terms ofrecognition accuracy and computational characteristics, such as the speed of learning and decoding. Methods: Creating an encoderdecodermodel of speech recognition using an attention mechanism; applying techniques of stabilization and regularization of neuralnetworks; augmentation of data for training; using parts of words as an output of a neural network. Results: An encoder-decodermodel was obtained using an attention mechanism for recognizing continuous Russian speech without extracting features or usinga language model. As elements of the output sequence, we used parts of words from the training set. The resulting model could notsurpass the basic hybrid models, but surpassed the other baseline end-to-end models, both in recognition accuracy and in decoding/learning speed. The word recognition error was 24.17% and the decoding speed was 0.3 of the real time, which is 6% faster than thebaseline end-to-end model and 46% faster than the basic hybrid model. We showed that end-to-end models could work without languagemodels for the Russian language, while demonstrating a higher decoding speed than hybrid models. The resulting model was trained onraw data without extracting any features. We found that for the Russian language the hybrid type of an attention mechanism gives thebest result compared to location-based or context-based attention mechanisms. Practical relevance: The resulting models require lessmemory and less speech decoding time than the traditional hybrid models. That fact can allow them to be used locally on mobile deviceswithout using calculations on remote servers.
{"title":"Encoder-decoder models for recognition of Russian speech","authors":"Nikita Markovnikov, I. Kipyatkova","doi":"10.31799/1684-8853-2019-4-45-53","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-4-45-53","url":null,"abstract":"Problem: Classical systems of automatic speech recognition are traditionally built using an acoustic model based on hidden Markovmodels and a statistical language model. Such systems demonstrate high recognition accuracy, but consist of several independentcomplex parts, which can cause problems when building models. Recently, an end-to-end recognition method has been spread, usingdeep artificial neural networks. This approach makes it easy to implement models using just one neural network. End-to-end modelsoften demonstrate better performance in terms of speed and accuracy of speech recognition. Purpose: Implementation of end-toendmodels for the recognition of continuous Russian speech, their adjustment and comparison with hybrid base models in terms ofrecognition accuracy and computational characteristics, such as the speed of learning and decoding. Methods: Creating an encoderdecodermodel of speech recognition using an attention mechanism; applying techniques of stabilization and regularization of neuralnetworks; augmentation of data for training; using parts of words as an output of a neural network. Results: An encoder-decodermodel was obtained using an attention mechanism for recognizing continuous Russian speech without extracting features or usinga language model. As elements of the output sequence, we used parts of words from the training set. The resulting model could notsurpass the basic hybrid models, but surpassed the other baseline end-to-end models, both in recognition accuracy and in decoding/learning speed. The word recognition error was 24.17% and the decoding speed was 0.3 of the real time, which is 6% faster than thebaseline end-to-end model and 46% faster than the basic hybrid model. We showed that end-to-end models could work without languagemodels for the Russian language, while demonstrating a higher decoding speed than hybrid models. The resulting model was trained onraw data without extracting any features. We found that for the Russian language the hybrid type of an attention mechanism gives thebest result compared to location-based or context-based attention mechanisms. Practical relevance: The resulting models require lessmemory and less speech decoding time than the traditional hybrid models. That fact can allow them to be used locally on mobile deviceswithout using calculations on remote servers.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49152061","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 : 2019-08-22DOI: 10.31799/1684-8853-2019-4-2-8
Kyriaki D. Tsilika
Introduction: Linear boundary value problems for Fredholm ordinary integro-differential equations are seldom consideredwith integral boundary conditions in the literature. In our case, integro-differential equations are subject to multipoint or nonlocalintegral boundary conditions. It should be noted that finding exact solutions even for multipoint problems or problems with nonlocalintegral boundary conditions with a differential equation is a difficult task. Purpose: Finding the uniqueness and existencecriterion of solutions for Fredholm ordinary integro-differential equations with multipoint or nonlocal integral boundary conditionsand obtaining exact solutions in closed form of such problems. Results: Within the class of abstract operator equations, for thespecial case of Fredholm integro-differential equations with multipoint or nonlocal integral boundary conditions, a criterion for theexistence and uniqueness of an exact solution is proved and the analytical representation of the solution is given. A direct methodanalytically solving such problems is proposed, in which all calculations are reproducible in any program of symbolic calculations.If the user sets the input parameters and the initial conditions of the problem, the computer codes check the conditions of existenceand uniqueness and of solution generate the analytical solution. The stages of the solution method are illustrated by twoexamples. The article uses computer algebra system Mathematica to demonstrate the results.
{"title":"An exact solution method for Fredholm integro-differential equations","authors":"Kyriaki D. Tsilika","doi":"10.31799/1684-8853-2019-4-2-8","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-4-2-8","url":null,"abstract":"Introduction: Linear boundary value problems for Fredholm ordinary integro-differential equations are seldom consideredwith integral boundary conditions in the literature. In our case, integro-differential equations are subject to multipoint or nonlocalintegral boundary conditions. It should be noted that finding exact solutions even for multipoint problems or problems with nonlocalintegral boundary conditions with a differential equation is a difficult task. Purpose: Finding the uniqueness and existencecriterion of solutions for Fredholm ordinary integro-differential equations with multipoint or nonlocal integral boundary conditionsand obtaining exact solutions in closed form of such problems. Results: Within the class of abstract operator equations, for thespecial case of Fredholm integro-differential equations with multipoint or nonlocal integral boundary conditions, a criterion for theexistence and uniqueness of an exact solution is proved and the analytical representation of the solution is given. A direct methodanalytically solving such problems is proposed, in which all calculations are reproducible in any program of symbolic calculations.If the user sets the input parameters and the initial conditions of the problem, the computer codes check the conditions of existenceand uniqueness and of solution generate the analytical solution. The stages of the solution method are illustrated by twoexamples. The article uses computer algebra system Mathematica to demonstrate the results.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47522451","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 : 2019-06-21DOI: 10.31799/1684-8853-2019-3-55-70
A. Smirnov, T. Levashova
Introduction: Socio-cyber-physical systems are complex non-linear systems. Such systems display emergent properties. Involvement of humans, as a part of these systems, in the decision-making process contributes to overcoming the consequences of the emergent system behavior, since people can use their experience and intuition, not just the programmed rules and procedures.Purpose: Development of models for decision support in socio-cyber-physical systems.Results: A scheme of decision making in socio-cyber-physical systems, a conceptual framework of decision support in these systems, and stepwise decision support models have been developed. The decision-making scheme is that cybernetic components make their decisions first, and if they cannot do this, they ask humans for help. The stepwise models support the decisions made by components of socio-cyber-physical systems at the conventional stages of the decision-making process: situation awareness, problem identification, development of alternatives, choice of a preferred alternative, and decision implementation. The application of the developed models is illustrated through a scenario for planning the execution of a common task for robots.Practical relevance: The developed models enable you to design plans on solving tasks common for system components or on achievement of common goals, and to implement these plans. The models contribute to overcoming the consequences of the emergent behavior of socio-cyber-physical systems, and to the research on machine learning and mobile robot control.
{"title":"Models of decision support in socio-cyber-physical systems","authors":"A. Smirnov, T. Levashova","doi":"10.31799/1684-8853-2019-3-55-70","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-3-55-70","url":null,"abstract":"Introduction: Socio-cyber-physical systems are complex non-linear systems. Such systems display emergent properties. Involvement of humans, as a part of these systems, in the decision-making process contributes to overcoming the consequences of the emergent system behavior, since people can use their experience and intuition, not just the programmed rules and procedures.Purpose: Development of models for decision support in socio-cyber-physical systems.Results: A scheme of decision making in socio-cyber-physical systems, a conceptual framework of decision support in these systems, and stepwise decision support models have been developed. The decision-making scheme is that cybernetic components make their decisions first, and if they cannot do this, they ask humans for help. The stepwise models support the decisions made by components of socio-cyber-physical systems at the conventional stages of the decision-making process: situation awareness, problem identification, development of alternatives, choice of a preferred alternative, and decision implementation. The application of the developed models is illustrated through a scenario for planning the execution of a common task for robots.Practical relevance: The developed models enable you to design plans on solving tasks common for system components or on achievement of common goals, and to implement these plans. The models contribute to overcoming the consequences of the emergent behavior of socio-cyber-physical systems, and to the research on machine learning and mobile robot control.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69413314","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 : 2019-06-21DOI: 10.31799/1684-8853-2019-3-94-104
I. Juwiler, I. Bronfman, N. Blaunstein
Introduction: This article is based on the recent research work in the field of two subjects: signal data parameters in fiber optic communication links, and dispersive properties of optical signals caused by non-homogeneous material phenomena and multimode propagation of optical signals in such kinds of wired links.Purpose: Studying multimode dispersion by analyzing the propagation of guiding optical waves along a fiber optic cable with various refractive index profiles of the inner optical cable (core) relative to the outer cladding, as well as dispersion properties of a fiber optic cable due to inhomogeneous nature of the cladding along the cable, for two types of signal code sequences transmitted via the cable: return-to-zero and non-return-to-zero ones.Methods: Dispersion properties of multimode propagation inside a fiber optic cable are analyzed with an advanced 3D model of optical wave propagation in a given guiding structure. The effects of multimodal dispersion and material dispersion causing the optical signal delay spread along the cable were investigated analytically and numerically.Results: Time dispersion properties were obtained and graphically illustrated for two kinds of fiber optic structures with different refractive index profiles. The dispersion was caused by multimode (e.g. multi-ray) propagation and by the inhomogeneous nature of the material along the cable. Their effect on the capacity and spectral efficiency of a data signal stream passing through such a guiding optical structure is illustrated for arbitrary refractive indices of the inner (core) and outer (cladding) elements of the optical cable. A new methodology is introduced for finding and evaluating the effects of time dispersion of optical signals propagating in fiber optic structures of various kinds. An algorithm is proposed for estimating the spectral efficiency loss measured in bits per second per Hertz per each kilometer along the cable, for arbitrary presentation of the code signals in the data stream, non-return-to zero or return-to-zero ones. All practical tests are illustrated by MATLAB utility.
{"title":"Optical data signals in fiber optic communication links with fading","authors":"I. Juwiler, I. Bronfman, N. Blaunstein","doi":"10.31799/1684-8853-2019-3-94-104","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-3-94-104","url":null,"abstract":"Introduction: This article is based on the recent research work in the field of two subjects: signal data parameters in fiber optic communication links, and dispersive properties of optical signals caused by non-homogeneous material phenomena and multimode propagation of optical signals in such kinds of wired links.Purpose: Studying multimode dispersion by analyzing the propagation of guiding optical waves along a fiber optic cable with various refractive index profiles of the inner optical cable (core) relative to the outer cladding, as well as dispersion properties of a fiber optic cable due to inhomogeneous nature of the cladding along the cable, for two types of signal code sequences transmitted via the cable: return-to-zero and non-return-to-zero ones.Methods: Dispersion properties of multimode propagation inside a fiber optic cable are analyzed with an advanced 3D model of optical wave propagation in a given guiding structure. The effects of multimodal dispersion and material dispersion causing the optical signal delay spread along the cable were investigated analytically and numerically.Results: Time dispersion properties were obtained and graphically illustrated for two kinds of fiber optic structures with different refractive index profiles. The dispersion was caused by multimode (e.g. multi-ray) propagation and by the inhomogeneous nature of the material along the cable. Their effect on the capacity and spectral efficiency of a data signal stream passing through such a guiding optical structure is illustrated for arbitrary refractive indices of the inner (core) and outer (cladding) elements of the optical cable. A new methodology is introduced for finding and evaluating the effects of time dispersion of optical signals propagating in fiber optic structures of various kinds. An algorithm is proposed for estimating the spectral efficiency loss measured in bits per second per Hertz per each kilometer along the cable, for arbitrary presentation of the code signals in the data stream, non-return-to zero or return-to-zero ones. All practical tests are illustrated by MATLAB utility.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44898315","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 : 2019-06-21DOI: 10.31799/1684-8853-2019-3-82-93
V. I. Khimenko
Introduction: Studying random processes with several stable states and random transitions between them is important because it opens a wide range of practical problems. The detailed information structure is not studied well enough, and there is no unified approach to the description and probabilistic analysis of such processes.Purpose: Studying the main probabilistic characteristics of random processes with two stable states, and probabilistic analysis of control over chaotic transitions under various control actions.Results: We show the ways to represent and preliminarily analyze random processes with two stable states on the phase plane and in the pseudophase space. A general probabilistic model for the processes in question is proposed in the form of a two-component probabilistic «mixture» of distributions. A probabilistic analysis was carried out for the principles of control over random transitions between different states. We have defined the basic probabilistic characteristics for the processes in a management action with a variety of spectral-correlation properties and a changeable threshold for random transitions. The Poisson model of a random transition flow is analyzed with an example of «high» threshold levels.Practical relevance: The methods of visual, qualitative and analytical research in studying dynamic systems with several stable states can be combined. The proposed probabilistic models, regardless of the physical nature of the processes under consideration, can be used in problems of probabilistic analysis, control over probabilistic structure of random transitions, and simulation of physical, technical or biological systems with random switching.
{"title":"Random processes with random transitions between stable states","authors":"V. I. Khimenko","doi":"10.31799/1684-8853-2019-3-82-93","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-3-82-93","url":null,"abstract":"Introduction: Studying random processes with several stable states and random transitions between them is important because it opens a wide range of practical problems. The detailed information structure is not studied well enough, and there is no unified approach to the description and probabilistic analysis of such processes.Purpose: Studying the main probabilistic characteristics of random processes with two stable states, and probabilistic analysis of control over chaotic transitions under various control actions.Results: We show the ways to represent and preliminarily analyze random processes with two stable states on the phase plane and in the pseudophase space. A general probabilistic model for the processes in question is proposed in the form of a two-component probabilistic «mixture» of distributions. A probabilistic analysis was carried out for the principles of control over random transitions between different states. We have defined the basic probabilistic characteristics for the processes in a management action with a variety of spectral-correlation properties and a changeable threshold for random transitions. The Poisson model of a random transition flow is analyzed with an example of «high» threshold levels.Practical relevance: The methods of visual, qualitative and analytical research in studying dynamic systems with several stable states can be combined. The proposed probabilistic models, regardless of the physical nature of the processes under consideration, can be used in problems of probabilistic analysis, control over probabilistic structure of random transitions, and simulation of physical, technical or biological systems with random switching.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46856974","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 : 2019-06-21DOI: 10.31799/1684-8853-2019-3-71-81
M. Sergeev, V. Nenashev, A. Sergeev
Introduction: The problem of noise-free encoding for an open radio channel is of great importance for data transfer. The results presented in this paper are aimed at stimulating scientific interest in new codes and bases derived from quasi-orthogonal matrices, as a basis for the revision of signal processing algorithms.Purpose: Search for new code sequences as combinations of codes formed from the rows of Mersenne and Raghavarao quasi-orthogonal matrices, as well as complex and more efficient Barker — Mersenne — Raghavarao codes.Results: We studied nested code sequences derived from the rows of quasi-orthogonal cyclic matrices of Mersenne, Raghavarao and Hadamard, providing estimates for the characteristics of the autocorrelation function of nested Barker, Mersenne and Raghavarao codes, and their combinations: in particular, the ratio between the main peak and the maximum positive and negative “side lobes”. We have synthesized new codes, including nested ones, formed on the basis of quasi-orthogonal matrices with better characteristics than the known Barker codes and their nested constructions. The results are significant, as this research influences the establishment and development of methods for isolation, detection and processing of useful information. The results of the work have a long aftermath because new original code synthesis methods need to be studied, modified, generalized and expanded for new application fields.Practical relevance: The practical application of the obtained results guarantees an increase in accuracy of location systems, and detection of a useful signal in noisy background. In particular, these results can be used in radar systems with high distance resolution, when detecting physical objects, including hidden ones.
{"title":"Nested code sequences of Barker — Mersenne — Raghavarao","authors":"M. Sergeev, V. Nenashev, A. Sergeev","doi":"10.31799/1684-8853-2019-3-71-81","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-3-71-81","url":null,"abstract":"Introduction: The problem of noise-free encoding for an open radio channel is of great importance for data transfer. The results presented in this paper are aimed at stimulating scientific interest in new codes and bases derived from quasi-orthogonal matrices, as a basis for the revision of signal processing algorithms.Purpose: Search for new code sequences as combinations of codes formed from the rows of Mersenne and Raghavarao quasi-orthogonal matrices, as well as complex and more efficient Barker — Mersenne — Raghavarao codes.Results: We studied nested code sequences derived from the rows of quasi-orthogonal cyclic matrices of Mersenne, Raghavarao and Hadamard, providing estimates for the characteristics of the autocorrelation function of nested Barker, Mersenne and Raghavarao codes, and their combinations: in particular, the ratio between the main peak and the maximum positive and negative “side lobes”. We have synthesized new codes, including nested ones, formed on the basis of quasi-orthogonal matrices with better characteristics than the known Barker codes and their nested constructions. The results are significant, as this research influences the establishment and development of methods for isolation, detection and processing of useful information. The results of the work have a long aftermath because new original code synthesis methods need to be studied, modified, generalized and expanded for new application fields.Practical relevance: The practical application of the obtained results guarantees an increase in accuracy of location systems, and detection of a useful signal in noisy background. In particular, these results can be used in radar systems with high distance resolution, when detecting physical objects, including hidden ones.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46423167","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 : 2019-06-21DOI: 10.31799/1684-8853-2019-3-37-44
O. Tomchina, D. N. Polyakhov, O. I. Tokareva, Alexander L. Fradkov
Introduction: The motion of many real world systems is described by essentially non-linear and non-stationary models. A number of approaches to the control of such plants are based on constructing an internal model of non-stationarity. However, the non-stationarity model parameters can vary widely, leading to more errors. It is only assumed in this paper that the change rate of the object parameters is limited, while the initial uncertainty can be quite large.Purpose: Analysis of adaptive control algorithms for non-linear and time-varying systems with an explicit reference model, synthesized by the speed gradient method.Results: An estimate was obtained for the maximum deviation of a closed-loop system solution from the reference model solution. It is shown that with sufficiently slow changes in the parameters and a small initial uncertainty, the limit error in the system can be made arbitrarily small. Systems designed by the direct approach and systems based on the identification approach are both considered. The procedures for the synthesis of an adaptive regulator and analysis of the synthesized system are illustrated by an example.Practical relevance: The obtained results allow us to build and analyze a broad class of adaptive systems with reference models under non-stationary conditions.
{"title":"Adaptive control of time-varying non-linear plants by speed-gradient algorithms","authors":"O. Tomchina, D. N. Polyakhov, O. I. Tokareva, Alexander L. Fradkov","doi":"10.31799/1684-8853-2019-3-37-44","DOIUrl":"https://doi.org/10.31799/1684-8853-2019-3-37-44","url":null,"abstract":"Introduction: The motion of many real world systems is described by essentially non-linear and non-stationary models. A number of approaches to the control of such plants are based on constructing an internal model of non-stationarity. However, the non-stationarity model parameters can vary widely, leading to more errors. It is only assumed in this paper that the change rate of the object parameters is limited, while the initial uncertainty can be quite large.Purpose: Analysis of adaptive control algorithms for non-linear and time-varying systems with an explicit reference model, synthesized by the speed gradient method.Results: An estimate was obtained for the maximum deviation of a closed-loop system solution from the reference model solution. It is shown that with sufficiently slow changes in the parameters and a small initial uncertainty, the limit error in the system can be made arbitrarily small. Systems designed by the direct approach and systems based on the identification approach are both considered. The procedures for the synthesis of an adaptive regulator and analysis of the synthesized system are illustrated by an example.Practical relevance: The obtained results allow us to build and analyze a broad class of adaptive systems with reference models under non-stationary conditions.","PeriodicalId":36977,"journal":{"name":"Informatsionno-Upravliaiushchie Sistemy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69413278","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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