Elektronika ir Elektrotechnika http://eejournal.ktu.lt/index.php/elt <div>ELEKTRONIKA IR ELEKTROTECHNIKA is&nbsp;a peer-reviewed bimonthly research journal of Kaunas University of Technology.</div> <p>The research journal ELEKTRONIKA IR ELEKTROTECHNIKA publishes previously unpublished manuscripts that will have a high impact in the field of electronics and electrical engineering. It targets not only certain field specialists, but the wider public also.</p> Kaunas University of Technology en-US Elektronika ir Elektrotechnika 1392-1215 <p>Copyright terms are indicated in the Republic of Lithuania Law on Copyright and Related Rights, Articles 4-37.</p> Title http://eejournal.ktu.lt/index.php/elt/article/view/23961 Elektronika ir Elektrotechnika Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 1 1 Editorial Board http://eejournal.ktu.lt/index.php/elt/article/view/23962 Elektronika ir Elektrotechnika Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 2 3 Nonlinear Controller with the Enhanced Resistance to Electromagnetic Disturbances http://eejournal.ktu.lt/index.php/elt/article/view/23963 <p><strong>The controller, which provides the control system dynamics similar to PID controller, but guarantees higher resistance of the control system to electromagnetic disturbances, has been proposed. The controller is similar to Proportional Integral (PI) controller. Distinctive feature of the controller is that the impact of the proportional term on the controller output signal is proportional to the control error raised to a power. The controller investigation results and their comparison with the results obtained using popular PID and PI controllers are presented.</strong></p> Algirdas Baskys Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 4 7 10.5755/j01.eie.25.4.23963 Sliding Mode Control for Position Tracking of Servo System with a Variable Loaded DC Motor http://eejournal.ktu.lt/index.php/elt/article/view/23964 <p>In this paper, the real-time position control of servo system is carried out using sliding mode control (SMC) method based on variable structure control (VSC). As DC Motors are commonly used in many industrial applications and robotics, studies in this paper have are tested on a DC servo system, which is designed and produced by Quanser Inc. Three different types of sliding mode controllers are designed for position control of servo system and, later, performance comparison of DC Motor on Servo system is made. According to results obtained from real-time servo system, it is shown that SMC method is robust against to disturbing effects, variabilities, and uncertainties on the systems. Outstanding part of this paper is that designed controllers are implemented to servo system in real-time with a variable loaded DC Motor. Moreover, this study shows that this control structure can be performed as high performance in the real-time motor control applications.</p> Akif Durdu Emre Hasan Dursun Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 8 16 10.5755/j01.eie.25.4.23964 Rotary Wireless Inductive Transmitter Powered by ZVS Resonant Convertor http://eejournal.ktu.lt/index.php/elt/article/view/23965 <p>In this work, an inductive wireless power transfer module powered by resonant converter is studied. The system consists of a zero voltage switching resonant converter and a rotary wireless power transmitter. The design of the rotary wireless power transmitter is presented. Simulation and experimental studies of the system confirm reliable operation of the power electronic converter with a wide range of loads. The zero voltage switching is maintained without significant adjustments in the switching frequency. This improves the system stability with variations in the air gap between transmitting and receiving modules or the magnetic coupling ratio. The studied system is suitable for powering loads placed on a rotating platform or other applications where the disadvantages of moving electrical contacts are undesirable.</p> Dimitar D. Arnaudov Nikolay D. Madzharov Nikolay L. Hinov Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 17 22 10.5755/j01.eie.25.4.23965 Hybrid K Based Influential Parameter Determination and Design Optimization of 220 kV High Voltage Insulator http://eejournal.ktu.lt/index.php/elt/article/view/23966 <p>Insulator failure generally occurs due to improper design, and if there exists sharp edges over the insulator surface. There is a need to detect the fragile parameters in the insulator design as they can cause large electrical stress, leading to insulation failure. In this paper, machine learning based approach is used to identify the fragile design parameter and thus determine an optimized design of the insulator, which will eventually decrease the voltage stress over it. A 220&nbsp;kV insulator is designed and electric field intensity and potential distribution for an assembly of live, ground and insulator is calculated for different geometries. The design parameters of the insulator are considered and varied. The electric field is calculated for the whole assembly of insulator to generate the most optimized design. The optimized design reduces the overall stress by 13.12&nbsp;%.</p> Anik Goswami Paromita Sadhu Pradip Kumar Sadhu Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 23 28 10.5755/j01.eie.25.4.23966 Improving Efficiency of Hybrid Electric Vehicle Using Matrix Converters http://eejournal.ktu.lt/index.php/elt/article/view/23967 <p>The paper deals with a novel enhanced connection of AC/AC powertrain for HEV hybrid vehicles. The substantial contribution of such a connection is the absence of 4QC auxiliary converter needed for autonomous and hybrid operational modes and its compensation by power-lesser 0×5 matrix converter. The main advantages of a simplified connection are beside smaller auxiliary converter sizing and possible better efficiency of the HEV powertrain. So, powertrain operation in autonomous traction accu-battery modes uses direct 0×5 configuration of traction 3×5 MxC matrix converter and in hybrid modes of ICE engine and accu-battery, besides traction 3×5 MxC matrix converter, uses the auxiliary 0×5 matrix converter. Modeling and simulation using Matlab-Simulink environment of traction powertrain configuration in autonomous modes are presented in the paper, as well as all simulation experiment results.</p> Branislav Dobrucky Slavomir Kascak Michal Prazenica Miriam Jarabicova Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 29 35 10.5755/j01.eie.25.4.23967 Blocking Characteristics of Photoconductive Switches Based on Semi-Insulating GaP and GaN http://eejournal.ktu.lt/index.php/elt/article/view/23968 <p>This article presents results of research work aimed at manufacturing photoconductive semiconductor switches (PCSSs) based on semi-insulating (SI) gallium phosphide (GaP) and gallium nitride (GaN). Currently, the work is in progress to determine the optimal values of PCSS parameters. In this article, the parameters of the selected semiconductor materials used for making PCSSs, the device operation principle, and possible areas of use are presented. The paper demonstrates the construction of test PCSSs based on SI GaP and SI GaN and results of blocking characteristics measurements without the illumination, as well as with illumination with a small photon flux. Further research directions are presented also.</p> Marek Suproniuk Karol Piwowarski Bogdan Perka Pawel Kaminski Roman Kozlowski Marian Teodorczyk Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 36 39 10.5755/j01.eie.25.4.23968 Secure and Efficient Hybrid Random Number Generator Based on Sponge Constructions for Cryptographic Applications http://eejournal.ktu.lt/index.php/elt/article/view/23969 <p>Random numbers constitute the most important part of many applications and have a vital importance in the security of these applications, especially in cryptography. Therefore, there is a need for secure random numbers to provide their security. This study is concerned with the development of a secure and efficient random number generator that is primarily intended for cryptographic applications. The generator consists of two subsystems. The first is algorithmic structure, Keccak, which is the latest standard for hash functions. The structure provides to generate secure random numbers. The second is additional input that generates with ring oscillators that are implemented on the FPGA. The additional inputs prevent reproduction and prediction of the subsequent random numbers. It is shown that the proposed generator is satisfies security requirements for cryptographic applications. In addition, NIST 800-22 test suite and autocorrelation test are used to demonstrate that generated random numbers have no statistical weaknesses and relationship among itself, respectively. Successful results from these tests show that generated numbers have no statistical weaknesses. Moreover, important advantage of the proposed generator is that it is more efficient than existing RNGs in the literature.</p> Selman Yakut Taner Tuncer Ahmet Bedri Ozer Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 40 46 10.5755/j01.eie.25.4.23969 Detection and Classification of Baseline-Wander Noise in ECG Signals Using Discrete Wavelet Transform and Decision Tree Classifier http://eejournal.ktu.lt/index.php/elt/article/view/23970 <p>An electrocardiogram (ECG) signal is usually contaminated with various noises, such as baseline-wander, power-line interference, and electromyogram (EMG) noise. Denoising must be performed to extract meaningful information from ECG signals for clinical detection of heart diseases. This work is focused on baseline-wander noise as it shares the same frequency spectrum as the ST segment of ECG signals. Hence, it is important to estimate the baseline-wander prior to its removal from ECG signals. This paper presents a method for classifying each segment of the ECG signal’s baseline-wander as minimal, moderate or large. We use the C4.5 decision tree algorithm to model the classifier using the WEKA data-mining tool. We test the proposed method on ECG signals obtained from the MIT-BIH arrhythmia database (48 ECG recordings, each slightly longer than 30&nbsp;min). We use 36 ECG recordings for training the classifier with the remaining 12 ECG recordings as the test data for classification. We partition each recording into 5 second, non-overlapping segments, which result in 361 segments for each record. The classification results show that the model classifier achieves an average sensitivity of 97.36&nbsp;%, specificity of 99.50&nbsp;%, and overall accuracy of 98.89&nbsp;% in classifying the baseline-wander noise in ECG signals. The proposed method effectively addresses the question of identifying the minimal baseline-wander segments. Moreover, the proposed framework may help in devising an algorithm for the selective filtering of moderate and large baseline-wander segments to achieve the best trade-off between accuracy and computational cost.</p> Syed Irtaza Haider Musaed Alhussein Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 47 57 10.5755/j01.eie.25.4.23970 Dynamic Resource Management of Real-Time Edge Services for Intelligent Vehicular Networks: A Case Study http://eejournal.ktu.lt/index.php/elt/article/view/23971 <p>The Internet of Vehicles requires high bandwidth and low latency services to unleash the potential of fully connected vehicles. Thus, the offloading proposals that successfully manage massive real-time service requests from vehicle nodes are needed. In this paper, we analyse the dynamic resource management for intelligent vehicular networks based on Multi-access Edge Computing architecture services. Using a combination of CloudSim and SUMO simulators, we present a case study of infotainment services in the city centre of Alicante, in Spain, that shows a high degree of optimality both in service allocation and migration when considering dense urban environments.</p> Katja Gilly Sonja Filiposka Salvador Alcaraz Carrasco Anastas Mishev Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 58 61 10.5755/j01.eie.25.4.23971 A Novel Approach for Detection of Fake News on Social Media Using Metaheuristic Optimization Algorithms http://eejournal.ktu.lt/index.php/elt/article/view/23972 <p>Deceptive content is becoming increasingly dangerous, such as fake news created by social media users. Individuals and society have been affected negatively by the spread of low-quality news on social media. The fake and real news needs to be detected to eliminate the disadvantages of social media. This paper proposes a novel approach for fake news detection (FND) problem on social media. Applying this approach, FND problem has been considered as an optimization problem for the first time and two metaheuristic algorithms, the Grey Wolf Optimization (GWO) and Salp Swarm Optimization (SSO) have been adapted to the FND problem for the first time as well. The proposed FND approach consists of three stages. The first stage is data preprocessing. The second stage is adapting GWO and SSO for construction of a novel FND model. The last stage consists of using proposed FND model for testing. The proposed approach has been evaluated using three different real-world datasets. The results have been compared with seven supervised artificial intelligence algorithms. The results show GWO algorithm has the best performance in comparison with SSO algorithm and the other artificial intelligence algorithms. GWO seems to be efficiently used for solving different types of social media problems.</p> Feyza Altunbey Ozbay Bilal Alatas Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 62 67 10.5755/j01.eie.25.4.23972 Combining SVD-DCT Image Watermarking Scheme Based on Perona-Malik Diffusion http://eejournal.ktu.lt/index.php/elt/article/view/23973 <p>In this paper, we propose an efficient image watermarking scheme based on combining Singular Value Decomposition (SVD) and Discrete Cosine Transform (DCT) transforms. The main idea consists of exploiting results obtained by the well-known Perona-Malik diffusion applied in image de-noising in watermarking domain by selecting significant blocks to embed a binary logo watermark. After applying the DCT on the selected blocks, the SVD is performed on each of these transformed blocks to modify a few numbers of its U matrix elements according to some defined conditions. Computer simulation and experimental results prove the efficiency of our proposed method against image processing attacks and outperform several previous schemes in terms of imperceptibility and robustness.</p> Sarra Belilita Nourredine Amardjia Tewfik Bekkouche Imen Nouioua Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 68 74 10.5755/j01.eie.25.4.23973 Outage Performance Analysis of Cell-Center/Edge Users Under Two Policies of Energy Harvesting http://eejournal.ktu.lt/index.php/elt/article/view/23974 <p>In this paper, two energy harvesting policies deploying in cooperative non-orthogonal multiple access (NOMA) systems are considered. After period of wireless power transfer, the NOMA users including cell-edge and cell-center users simultaneously transmit the superposition coded symbols to the base station (BS). In the last time slot, the BS decodes to achieve its signal based on superposition coded symbol with corresponding power allocation factors. This paper provides exact expressions of outage probability in two schemes. Performance gap of two NOMA users can be raised by providing different power allocation factors. It is confirmed by numerical result. Distance and data rate are main factors affecting outage performance. Scheme I exhibit scenario where power beacon transmits energy signal to NOMA user while the BS feeds energy to NOMA user in Scheme II. It is shown that outage performance of Scheme I is better than that of Scheme II.</p> Dinh-Thuan Do Anh-Tu Le Chi-Bao Le Si-Phu Le Hong-Nhu Nguyen Lukas Sevcik Miroslav Voznak Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 75 80 10.5755/j01.eie.25.4.23974 Data Ridden Pilots Based Estimation of Sparse Multipath Massive MIMO Channels Using Orthogonal Matching Pursuit http://eejournal.ktu.lt/index.php/elt/article/view/23975 <p>Massive Multiple-Input Multiple-Output (MIMO) is envisioned to be a strong candidate technology for the upcoming 5th generation (5G) of wireless communication networks. This research work presents a novel Compressed Sensing (CS) and Superimposed Training (SiT) based technique for estimating the sparse uplink channels in massive MIMO systems. The proposed technique involves arithmetic addition of a periodic, but low powered training sequence with each user’s information sequence. Consequently, separately dedicated resources for the pilot symbols are not needed. Moreover, to attain the estimates of the Channel State Information (CSI) in the uplink, the sparsity exhibited by the MIMO channels is exploited by incorporating CS based Orthogonal Matching Pursuit (OMP) algorithm. For decoding the transmitted information symbols of each user, a Linear Minimum Mean Square Error (LMMSE) based equalizer is incorporated at the receiving Base Station (BS). Based on the obtained simulation results, the proposed SiT-OMP technique outperforms the existing Least Squares (SiT) channel estimation technique. The comparison is done using performance metrics of the Bit Error Rate (BER) and the Normalized Channel Mean Square Error (NCMSE).</p> Babar Mansoor Moazzam Islam Tiwana Syed Junaid Nawaz Abrar Ahmed Abdul Haseeb Ataul Aziz Ikram Copyright (c) 2019 Elektronika ir Elektrotechnika 2019-08-07 2019-08-07 25 4 81 87 10.5755/j01.eie.25.4.23975