Information and telecommunication sciences: international research journal, Vol. 13, N. 1
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Документ Відкритий доступ Uniform rectangular array radar optimization for efficient and accurate estimation of target parameters(National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 2022) Romanuke, VadimBackground. If the intensity of moving targets within a surveyed area is low, some sensors of the uniform rectangular array (URA) radar can be (symmetrically) turned off. However, this does not guarantee detection of any target because sometimes the threshold detection, by which the main parameters of the target are estimated, fails. Objective. In order to improve detection of ground-surface targets, the goal is to find an optimal number of URA radar sensors along with improving the stage of threshold detection. The criterion is to determine such a minimum of these sensors at which the main parameters of the target are accurately estimated. In addition, the threshold detection is to be modified so that a number of detection fails would be lesser. Methods. To achieve the said goal, the URA radar is simulated to detect a single target. The simulation is configured and carried out by using MATLAB® R2021b Phased Array System ToolboxTM functions based on a model of the monostatic radar. Results. There is a set of quasioptimal URA sizes included minimally-sized and maximally-sized URAs. The best decision is to use, at the first stage, the minimally-sized URA (by turning off the maximal number of vertical and horizontal sensors). If the detection fails, then the maximally-sized URA radar is tried. If the detection fails again, the next minimally-sized URA is tried, in which one horizontal sensor is additionally turned on. Additional horizontal sensors must be enabled while the detection fails but the number of vertical sensors should not be greater by about a third of their minimal number. Conclusions. An optimal number of URA radar sensors is in either the minimally-sized URA (or close to it) or maximallysized U RA ( or c lose t o i t). The U RA s ize i s r egulated b y ( symmetrically) turning off vertical and horizontal sensors. The threshold detection stage is modified so that the threshold is gradually decreased while the detection fails. This allows increasing a number of detected targets on average, which is equivalent to increasing the probability of detection.Документ Відкритий доступ Method of operational calculation of coordinates of intermediate route points of flying information robot(National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 2022) Lysenko, Olexandr; Valuiskyi, Stanislav; Yavisya, Valerii; Tachinina, Olena; Novikov, Valery; Sushin, IhorBackground. The article describes an operational calculation method of the intermediate points' coordinates of the flying information robot (FIR) route, which collects information from mobile sensors of a mobile wireless sensor network. Objective. The purpose of the paper is to develop a method that allows building the movement trajectory of the LIR, minimizing the time for collecting information from mobile sensors. Methods. The quickly calculating method of the route' coordinates of intermediate points involves setting a quasi-mobile mode of sensors movement and the consistent use of algorithms for solving the navigation problem, the clustering problem, and the problem of finding the flying trajectory around information collection points from mobile sensors clusters that formed at the time of the start of collecting information. Results. A method has been developed that uses the procedures of quantitative calculation of the indicators of the structural-information connectivity of wireless sensor networks with mobile sensors. These indicators take into account the presence of not only a structural connection, but also a guaranteed information exchange between a given sender-destination pair. Conclusions. The developed method makes it possible to improve the indicators of the structural-information connectivity of wireless sensor networks with mobile sensors: k-connectivity and network bandwidth.Документ Відкритий доступ Terahertz communication systems for high-definition and ultra-high-definition television transmission(National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", 2022) Avdieienko, Hlib; Slyvka, Andrii; Dykyi, OleksiiДокумент Відкритий доступ New composite Barker codes, Gold codes and Kasamisequences in broadband signal synchronization systems(National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", 2022) Maksymov, Volodymyr; Gatturov, Viktor; Khrapovytsky, IgorBackground. Currently, noise-like signals (NLS) are widely used, which provide high noise immunity of broadband communication systems (BSS) when transmitting confidential information in an open radio channel, especially in emergency situations. Increasing the efficiency of the NSS is possible with the use of more advanced code structures, in particular, new methods for constructing Barker code sequences used in wireless communication systems with direct sequence spread spectrum technology. Objective. The aim of the work is to study new composite codes of Barker, Gold and Kasami as synchronization signals of the BSS using simulation. Methods. Analytical calculation methods are used, as well as simulation modelling in the MatLab software package. Results. Modelling in the MatLab environment of new composite Barker codes, Gold codes and Kasam isequences as synchronization signals of the BSS showed that the composite sequences of Barker 49 and 77 in the range of SNR change from 0dB to 30dB are more resistant to interference compared to Kasami-63 and Gold-63 by (0,35 – 22,10)%. Conclusions. Modelling in the MatLab software package showed a greater noise immunity of the new composite Barker codes compared to the Gold and Kasami sequenceswhen used as synchronization signals of the BSS.Документ Відкритий доступ Analysis of differences in the characteristics of queuing systems with the dynamics of input streams self-similarity(National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 2022) Uryvsky, Leonid; Kryklyva, AnastasiiaBackground. Modern queuing theory is used in many fields and in telecommunications it plays an important role. Today, the modern way to implement queuing systems is a cloud environment. And the main problem of queuing system is to ensure the quality of service. Objective. The purpose of the paper is to study the indicators of service quality of queuing systems with different initial characteristics, to analyse the service quality characteristics when comparing quantitative characteristics of different parameters of queuing systems to identify features of queuing system with self-similarity. Methods. Analyse the theory of QoS, types of distribution, such as Poisson and Weibull, as well as the properties of self-similar traffic. Compare the values of the main parameters that provide the desired quality of service at different inputs and different Hearst parameters. Results. The importance of taking into account the self-similarity factor f or t he a ccuracy o f t he v alues o f t he parameters in the calculation that ensure the quality of service in the QMS. Conclusions. Research of the influence of self-similar traffic on the quality of service in queuing systems.Документ Відкритий доступ Mems-based wireless vibration transducer for condition monitoring(National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 2022) Ivanov, Sergi; Oliinyk, PavloBackground. When monitoring vibration of rotating machines, especially heavy ones, problems with cables of transducers often emerge. Those cables are usually long, heavy and prone to damage. Objective. The purpose of the paper is to develop a wireless vibration transducer, which is free of those problems, on the base of MEMS accelerometer. Sensor developed should provide low power consumption, linear frequency response at least in 10…1000 Hz range, calculate vibration RMS and detect machine condition based on it. Methods. Develop wireless sensor design based on 8-bit MCU. Develop method of MEMS frequency response correction, based on spectral analysis. Compare sensor developed with industrial piezoelectric ones. Results. Transducer developed can be used instead of the industrial piezoelectric vibration transducers. Moreover, MEMSbased transducer allows one to move basic machine condition detection process from the high–level system to transducer level. That, in turn, allows one to reduce network traffic and simplify condition monitoring system as a whole. Conclusions. MEMS-based wireless vibration transducer for condition monitoring is developed. Tests conducted showed that the transducer developed is well–behaved and its precision is comparable to one of industrial piezoelectric transducers.Документ Відкритий доступ Protection against the effect of different classes of attacks on uav control channels(National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 2022) Kaidenko, Mykola; Kravchuk, SerhiiBackground. Protecting the data link of an unmanned aerial vehicle (UAV) is a top priority for countering attacks on UAVs. In this case, it should be taken into account that even the use of the most protected from the effects of deliberate interference types of modulation with spectrum spread does not guarantee the protection of such a channel. Objective. The vulnerability of UAVs using cyber-attacks on a wireless channel is quite large, its study remains relevant, and therefore further development of complex effective means of countering such cyber-attacks is necessary, which is the purpose of this work. Moreover, the countermeasures presented in the work are based on the use of architectural solutions for building a UAV communication channel, which is different from traditional ones. Methods. Structural-functional methods for constructing a secure wireless system of UAV communication channels are being investigated. Results. A block diagram of the organization of UAV electronic countermeasures has been developed, which shows the data transmission channel from the UAV ground control station, the organization of the jamming channel, and the structure of the signal at the receiver input with all distortions and interference. Interferences that can act as a signal of intentional interference from an electronic warfare station are presented and analysed. An architectural solution is proposed using two channels in different frequency bands for the UAV control channel. A schematic structure of the organization of such a communication channel is presented. An expression is given for the margin of safety of a communication channel against a specific intentional interference. It is shown that the proposed architectural solution will have a similar effect when exposed to structured interference on the communication channel. In the case of the impact of imitation interference, the situation will be ambiguous, so it is very important to correctly determine the channel that is affected by intentional interference. It is shown that to determine the presence of intentional interference, it is necessary to have at least one more degree of freedom, which is necessary for classifying such interference and effectively counteracting it. Such a degree of freedom can be achieved by additional dimensions or architectural solutions for building a communication system. Conclusions. The types of intentional interference that can affect the UAV communication channel, the features of their application, and characteristics to ensure effective electronic protection are presented. Scenarios for counteracting the influence of attacks on UAV control channels are proposed. Scenarios with qualitative estimates are given, on the basis of which algorithms for detecting intentional interference and algorithms for counteracting the influence of such interference on the UAV communication channel can be built. It is assumed that the algorithms use averaged parameters, the length of the averaging interval is chosen as a multiple of the length of one data frame, which makes it possible to exclude from consideration fast fading in the communication channel that occurs in the case of frequency selective channels.Документ Відкритий доступ Іmplementation of medical mask recognition technology in real time using a video camera(National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, 2022) Prochukhan, Dmytro; Korablev, MykolaBackground. The coronavirus pandemic (COVID-19) has led to a major global health crisis due to the rapid spread of the virus. The World Health Organization has provided guidelines for protection against this disease. One of the effective recommendations is to wear a medical mask in public or crowded places. Involving human resources to monitor how these requirements are met is ineffective. It is necessary to automate the process of determining a properly dressed medical mask in real time using a video camera. The authors have developed an application that effectively copes with this task. Objective. The purpose of thew paper is the application development of a medical mask recognition in real time using a video camera, adapted for the use in modern Ukrainian reality with high accuracy and low system requirements. Methods. Analysis of existing analogues in the world, building a model of convolutional neural network, the architecture of which will detect and classify the image obtained from the camcorder in real time, create application architecture, develop a model in Python programming language, application testing. Results. A convolutional neural network of its own architecture has been created. The use of the Adam algorithm to optimize learning and use binary cross entropy as a cost function is substantiated. The method of face recognition using Haar features has been improved. High rate of convolutional neural network training was obtained: the training set accuracy - 97.46%, the test set accuracy - 97.23%, the cost function value at the training set - 2.37%, the cost function value at the test set - 2.57%. An application consisting of three modules has been developed: a machine learning module, an image processing module, a video camera activation module and a mask recognition device. Conclusions. The application effectively copes with the task of recognizing the presence of a medical mask in real time. The developed model in comparison with the analogues has a smaller size and simpler architecture without compromising accuracy or speed. The software has been successfully tested on various operating systems and hardware configurations. The application can be used in areas where there is a need to automate the process of determining the presence and accuracy of wearing a medical mask in real time.