Zaitsev S.V.,Cherkasy State Technological University |
Kazymyr V.V.,Cherkasy State Technological University
Radioelectronics and Communications Systems | Year: 2017
The paper deals with the issue of enhancing the performance efficiency of wireless networks built by using the with automatic repeat request scheme for retransmission. The proposed method is based on adaptive change of polynomials of recursive systematic convolutional codes forming a part of turbo codes and aimed at enhancing their correcting properties at the expense of increasing the code limitation at each data block retransmission for the set coding rate. In this case, the decoding algorithm of turbo codes is modified in respect of using the introduced additional a priori information during the calculation of logarithmic ratios of likelihood functions or log-likelihood ratios (LLR) for each component decoder obtained during the earlier repeat requests for retransmission. The results of simulation modeling showed that the application of this technique made it possible to obtain the energy gain in coding and enhance the data transmission accuracy as compared to the fourth generation mobile communication system, such as 4G LTE-Advanced. © 2017, Allerton Press, Inc.
Didkowsky R.M.,Cherkasy State Technological University |
Oleksienko N.V.,Cherkasy State Technological University
CriMiCo 2013 - 2013 23rd International Crimean Conference Microwave and Telecommunication Technology, Conference Proceedings | Year: 2013
It is shown that one of the underlying causes of the performance deterioration in communication system utilizing stochastic signals is bit energy fluctuations. Normalization of the signal provides a significant gain in performance of communication system using a stochastic carrier. © 2013 CriMiCo'2013 Organising Committee, CrSTC.
Herasymenko I.,Cherkasy State Technological University
Modern Problems of Radio Engineering, Telecommunications and Computer Science, Proceedings of the 13th International Conference on TCSET 2016 | Year: 2016
This article is devoted to the protection of data systems in support of distance learning. Describes various remedies, such as hardware, software, protective transformations, and organizational protection. The key areas that need protection and suggested possible options for their protection, such as a captcha in the registration, protection class IP address and service of the copy protection are analyzed. The proposed remedies undertaken on the example of e-learning course Information technology analysis, systems deployed in the system of decision support based on Moodle. © 2016 National University Lviv Polytechnic.
Voytenko V.,Cherkasy State Technological University |
Stepenko S.,Cherkasy State Technological University
2015 IEEE 35th International Conference on Electronics and Nanotechnology, ELNANO 2015 - Conference Proceedings | Year: 2015
The article presents a comparative analysis of three approaches to the modelling of a zero-current switching quasi-resonant boost converter (ZCS-QRBC) performed in Matlab Simulink. The widely used approach based on the use of Power Electronics library components from SimPowerSystems Toolbox is found to be the most effective for an introduction at a glance to the basics of ZCS-QRBC operation as well as for educational purposes. A SPICE-model of ZCS-QRBC based on physical principles of elements operation is preferable to use to obtain the practical results quickly, elaborate ZCS-QRBC topology, select components, and establish a background for experimental investigations. In the later stages of system design the limited use of the simplified model is possible in order to comply with requirements of existing computational resources. It allows estimating the influence of a control method on the system dynamics and control accuracy or stabilization of a certain parameter. © 2015 IEEE.
Didkowskiy R.M.,Cherkasy State Technological University
CriMiCo 2012 - 2012 22nd International Crimean Conference Microwave and Telecommunication Technology, Conference Proceedings | Year: 2012
A laboratory model of a differential noise-shift-keying communication system was developed. The system uses transferred reference signal and autocorrelation reception. The tests of system performance in a binary, multi-channel and synchronization modes were carried out. Previously proposed methods of signal modulation and signal processing have proved to be effective in experimental studies. © 2012 CriMiCo.
Stepenko S.A.,Cherkasy State Technological University
Technical Electrodynamics | Year: 2014
The paper is devoted to energy efficiency analysis of power factor corrector based on boost converter by modeling in Matlab Simulink. The different types of pulse-width modulation, including trailing-edge modulation, leading-edge modulation and double-edge modulation, were investigated. The study shows, that using modern semiconductor devices with modulation in the frequency range 20-180 kHz, it is possible to build an active power factor corrector with high performance (efficiency up to 97%, total harmonic distortion of the input current 7-13%, power factor 0,992-0,997). At frequencies less than 100 kHz the use of leading-edge PWM or double-edge PWM instead of trailing-edge PWM is more efficient based on power factor and total harmonic distortion of the current.
Dikhtyaruk I.V.,Cherkasy State Technological University
Technical Electrodynamics | Year: 2014
The methodology for selection of rational installation location of partitioning switching devices, namely disconnectors of a new generation RLK-10, RLN-10 with autolink ABB has been proposed in this work. It is shown that for selection of rational installation location of such partitioning switching devices the distribution networks with the voltage of 6-10 kV of any configuration, you can use the objective function - reduction undersupply of electricity to consumers. By bringing the distribution function of consumer along the transmission line to the linear, logarithmic or exponential form, was obtained rational installation location sektsionuyuchyh disconnectors. For the case of uniform power distribution along the length of the line was obtained efficient installation location disconnector, which is 64% of the total length of the line.
Voytenko V.P.,Cherkasy State Technological University
Technical Electrodynamics | Year: 2016
It is considered the one way of increasing the efficiency of electrically controlled industrial systems by means of improving their dynamics in the conditions of restrictions on control actions, as well as increasing of resistance to disturbances and changes in the parameters. For this purpose a quasi-optimal control algorithm is used for pulse converter, which together with a plant is simulated by using of artificial neural network (ANN). It is analyzed the system with implementation of the controller in the form of pre-trained ANN. The basic problems associated with implementation of the ANN in embedded systems are discussed too. Simulated results of investigations are given.
Sytnyk A.,Cherkasy State Technological University
Modern Problems of Radio Engineering, Telecommunications and Computer Science - Proceedings of the 11th International Conference, TCSET'2012 | Year: 2012
In this paper briefly described a multiple access technique for differential noise shift keying (DNSK) system. © 2012 Lviv Polytechnic Natl Univ.
Khomenko E.,Cherkasy State Technological University
Chemistry and Chemical Technology | Year: 2014
Potential energy curves of the ground and a few excited states of the BrO- and HOBr along the photodissociation reactions, which correlate with lower dissociation limits are obtained on the base of calculations results by ab initio method. The singlet-triplet nonadiabatic transition with dissociation of the ground X1Σ+ state to lower limit O(3P) + Br-(1S) is predicted on the basis of calculations results. The ground singlet X1Σ+ state of the BrO- has predissociative and metastable character for the upper vibrational levels. It is shown that the singlet-triplet transition to the lower triplet state a3A"←X1A' is responsible for a weak HOBr absorption in the visible region (440-650 nm). © Khomenko E., 2014.