AEEE. 2018, vol. 16

Permanent URI for this collectionhttp://hdl.handle.net/10084/123530

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Now showing 1 - 20 out of 57 results

Speckle noise reduction in medical ultrasound images using modelling of shearlet coefficients as a Nakagami prior
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Garg, Amit; Khandelwal, Vineet
The diagnosis of UltraSound (US) medical images is affected due to the presence of speckle noise. This noise degrades the diagnostic quality of US images by reducing small details and edges present in the image. This paper presents a novel method based on shearlet coefficients modeling of log-transformed US images. Noise-free log-transformed coefficients are modeled as Nakagami distribution and speckle noise coefficients are modeled as Gaussian distribution. Method of Log Cumulants (MoLC) and Method of Moments (MoM) are used for parameter estimation of Nakagami distribution and noise free shearlet coefficients respectively. Then noise free shearlet coefficients are obtained using Maximum a Posteriori (MaP) estimation of noisy coefficients. The experimental results were presented by performing various experiments on synthetic and real US images. Subjective and objective quality assessment of the proposed method is presented and is compared with six other existing methods. The effectiveness of the proposed method over other methods can be seen from the obtained results.
Optimization of the position of single-lead wireless sensor with low electrodes separation distance for ECG-derived respiration
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Svobodová, Helena; Vavrinský, Erik; Turoňová, Daniela; Donoval, Martin; Daříček, Martin; Telek, Peter; Kopáni, Martin
A classical method for estimation of respiratory information from electrocardiogram (ECG), called ECG - derived respiration (EDR), is using flexible electrodes located at standard electrocardiography positions. This work introduces an alternative approach suitable for miniaturized sensors with low inter-electrode separation and electrodes fixed to the sensor encapsulation. Application of amplitude EDR algorithm on single-lead wireless sensor system with optimized electrode positions shows results comparable with standard robust systems. The modified method can be applied in daily physiological monitoring, in sleep studies or implemented in smart clothes when standard respiration techniques are not suitable.
A novel and fast hardware implementation for Golay Code encoder
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Nazeri, Morteza; Rezai, Abdalhossein
The Error Correction Code (ECC) is utilized to reduce the probability of error in digital systems. The binary Golay code is an ECC that can correct any combination of three or fewer random errors over a block of 23 digits. This code can be extended by appending a parity check bit to each codeword. There are several algorithms for constructing of Golay code, but more of them are not comfortable for hardware implementation. In this paper, an efficient hardware architecture is presented for the encoder of both binary Golay code and extended Golay code based on CRC. The proposed Golay code encoder is constructed of three units, which are designed carefully: data path, control unit and conversion unit. The proposed architecture is implemented on FPGA using Xilinx ISE 14.2. The implementation results demonstrate that low latency, high throughput, low area and less complexity are the advantages of this architecture compared to previous architectures. Thus, this hardware module can be used for high-speed digital systems.
Control of the weakly damped System with the embedded system support
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Paškala, Marek; Šedo, Jozef; Kondelová, Anna
This paper deals with the experimental verification of the importance of embedded systems with an applied MEMS sensor in controlling weakly damped systems. The aim is to suppress actively residual oscillations. The model of a planar physical pendulum with a prismatic joint was chosen for the experiment. The sensor made by MEMS technology, in which three-axis gyroscope and three-axis accelerometer are integrated, has been used for sensing the angle of deflection of the load from the equilibrium position. The simulation model represents the crane arm with a moving carriage
On outage probability and throughput performance of cognitive radio inspired NOMA relay system
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Tran, Thanh-Nam; Do, Dinh-Thuan; Vozňák, Miroslav
To improve the throughput and the outage probability of the Cognitive Radio (CR) inspired system, a novel Non-Orthogonal Multiple Access (NOMA) can be deployed to adapt multiple services in 5G wireless communication. In this scheme, after the reception of the superposition coded symbol with a predefined power allocation factors from the primary source, the relay decodes and forwards with a new superposition coded symbol (i.e. allocating another power factors) to the destination. By employing twin antenna design at the relay, the bandwidth efficiency in such scheme will be improved. Assuming Rayleigh fading channels, the closed-form expressions in terms of throughput and the outage performance are derived. Through numerical results, they showed that the outage performance of the proposed scheme using a Single Antenna (SA) scheme at the relay is better than a Twin Antenna (TA) scheme because SA scheme is not affected by its own antenna interference.
Design of interfering mobile device in the band Wi-Fi with magnetron
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Leuchter, Jan; Quang, Huy Dong
The aim of this article is to design an interfering mobile device with a magnetron for the interference in Wi-fi signal in the band 2.4-2.5GHz. Propulsion of the interfering mobile device will be implemented using system of the stepper motor, which will be controlled with the help of the microcontroller ATmega 16. In order to deal with the interfering part, it is necessary to design an inverter 12V/4000V and 50-60Hz. The inverter is a supply of the high-powered vacuum tube that generates microwaves; magnetron. Magnetron is used as a source of electromagnetic interference high-frequency acting on targets, which operates in the band of Wi-Fi signal. For example, waves of high-frequency radio damage on-board electronic devices of the UAV, and by the way, we can disable fly of UAV in demarcated areas. The interfering mobile device will be used as a preparation interference and measurement electromagnetic compatibility of electronic military equipment.
Improved optimal power flow for a power system incorporating wind power generation by using Grey Wolf Optimizer algorithm
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Haddi, Sebaa; Bouketir, Omrane; Bouktir, Tarek
In this paper, an efficient Grey Wolf Optimizer (GWO) search algorithm is presented for solving the optimal power flow problem in a power system, enhanced by wind power plant. The GWO algorithm is based on meta-heuristic method, and it has been proven to give very competitive results in different optimization problems. First, by using the proposed technique, the system independent variables such as the generators’ power outputs as well as the associated dependent variables like the bus voltage magnitudes, transformer tap setting and shunt VAR compensators values are optimized to meet the power system operation requirements. The Optimal power flow study is then performed to assess the impact of variable wind power generation on system parameters. Two standard power systems IEEE30 and IEEE57 are used to test and verify the effectiveness of the proposed GWO method. The obtained results are then compared with others given by available optimization methods in the literature. The outcome of the comparison proved the superiority of the GWO algorithm over other meta-heuristics techniques such as Modified Differential Evolution (MDE), Enhanced Genetic Algorithm (EGA), Particle Swarm Optimization (PSO), Biogeography Based Optimization (BBO), Artificial Bee Algorithm (ABC) and Tree-Seed Algorithm (TSA).
Application of a novel modified hybrid algorithm for solving Dynamic Economic Dispatch problem with practical constraints
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Hamed, Mostefa; Mahdad, Belkacem; Srairi, Kamel; Mancer, Nabil
Dynamic Economic Dispatch (DED) is a highly complex nonlinear optimization problem with practical constraints. The aim of DED is to optimize dynamically the active power of generating units over operating time considering practical constraints such as valve point effect, prohibited zones, ramp rate limits and total power losses. In order to overcome the drawback of the two standard metaheuristics such as Firefly Algorithm (FA) and Time Varying Acceleration based Particle Swarm Optimization (PSOTVAC), a hybrid method called FAPSOTVAC is proposed to improve the solution of DED. The main idea introduced towards combining FA and PSOTVAC is to create a flexible equilibrium between exploration and exploitation during search process. The robustness of the proposed hybrid method is validated on many practical power systems (10 and 30 units) to minimize the total fuel cost considering all practical constraints. The results found prove the efficiency of the proposed FAPSOTVAC in terms of solution quality and convergence characteristics.
Extended Kalman filter based states estimation of unmanned quadrotors for altitude-attitude tracking control
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Ghanai, Mouna; Medjghou, Ali; Chafaa, Kheireddine
In this paper, an efficient Grey Wolf Optimizer (GWO) search algorithm is presented for solving the optimal power flow problem in a power system, enhanced by wind power plant. The GWO algorithm is based on meta-heuristic method, and it has been proven to give very competitive results in different optimization problems. First, by using the proposed technique, the system independent variables such as the generators’ power outputs as well as the associated dependent variables like the bus voltage magnitudes, transformer tap setting and shunt VAR compensators values are optimized to meet the power system operation requirements. The Optimal power flow study is then performed to assess the impact of variable wind power generation on system parameters. Two standard power systems IEEE30 and IEEE57 are used to test and verify the effectiveness of the proposed GWO method. The obtained results are then compared with others given by available optimization methods in the literature. The outcome of the comparison proved the superiority of the GWO algorithm over other meta-heuristics techniques such as Modified Differential Evolution (MDE), Enhanced Genetic Algorithm (EGA), Particle Swarm Optimization (PSO), Biogeography Based Optimization (BBO), Artificial Bee Algorithm (ABC) and Tree-Seed Algorithm (TSA).
Extended second order sliding mode control for mismatched uncertain systems with only output measurable
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Huynh, Van Van; Minh, Bui Le Ngoc; Nguyen, Tam Minh; Dong, Chau Si Thien; Duy, Vo Hoang
Most existing Second Order Sliding Mode Control (SOSMC) approaches are achieved under assumptions that 1) all of state variables must be accessible; 2) the second derivative of all state variables must exist, even though mathematical model of systems uses the first order equations. In this paper, a new adaptive SOSMC scheme is proposed for mismatched uncertain systems in which these above assumptions are required. In this proposed method, only output variables are used in the sliding surface and controller design. The advantage of no need of all state variables in controller design makes the method more useful and realistic since it can be applied to a wider class of systems. Finally, a vertical take-off and landing aircraft at the nominal airspeed of 135~knots is simulated to demonstrate the advantages and effectiveness of the proposed approach.
An implementation of rotor speed observer for sensorless induction motor drive in case of machine parameter uncertainty
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Vo, Hau Huu; Brandštetter, Pavel; Tran, Thinh Cong; Dong, Chau Si Thien
The paper describes observers using model reference adaptive system for sensorless induction motor drive with the pulse width modulator and the direct torque control under the circumstances of incorrect information of induction motor parameters. An approximation based on the definition of the Laplace transformation is used to obtain initial values of the parameters. These values are utilized to simulate sensorless control structures of the induction motor drive in Matlab-Simulink environment. Performance comparison of two typical observers is carried out at different speed areas and in presence of parameter uncertainty. A laboratory stand with the induction motor drive and load unit is set up to verify the properties of observers. Experimental results confirm the expected dynamic properties of selected observer.
PSO optimized PID regulator for a variable frequency brushless synchronous generator
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Smail, Hassen; Smail, Mostafa Kamel; Fetha, Cherif; Bahi, Tahar
The aim of this paper is to describe development of a new control structure for Automatic Voltage Regulator system. This approach is based on the optimization of the control voltage magnitude of a brushless excitation synchronous alternator machine operating at variable speed. The choice of the machine type is justified by its attractiveness in several areas such as the aircraft domain due to its autonomy and robustness. The considered control technique is based on the simultaneous optimization of two regulators introduced in the loop control. The parameters of the Proportional Integral Derivatives (PID) regulator have been optimized using the Particle Swarm Optimization (PSO), which is considered as an attractive method considering the wide operating speed range, and the load variations compared with the classical methods such as Ziegler Nichols. Many robustness tests are carried out by considering the parameters variations as well as the perturbation connection and disconnection of the load at low and high speeds.
Modeling and robust control of a grid connected direct driven PMSG wind turbine by ADRC
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Aboudrar, Imad; El Hani, Soumia; Mediouni, Hamza; Aghmadi, Ahmed
In this paper, we present the modeling and control of a grid connected Variable Speed Wind Energy Conversion System (VS-WECS) based on a Direct Driven Permanent Magnet Synchronous Generator (DD-PMSG). A new robust control has been proposed and utilized to operate the wind turbine so as to extract the maximum power from the wind energy and to ensure a unit power factor. This control is known as the Active Disturbance Rejection Control (ADRC) and it is based on the Extended State Observer (ESO). It consists in controlling, through the stator currents, the machine side converter in order to adapt the rotational speed of the generator to the different wind speed profiles (Maximum Power Point Tracking MPPT). In addition, it ensures the control of the DC bus voltage and the exchange of active and reactive powers between the wind turbine and the electrical power grid. In order to evaluate the performance of the proposed control a series of simulations are made under the MATLAB/SIMULINK environment. The results obtained by simulation show that the proposed strategy is efficient in terms of stability and precision as well as for the robustness with regard to the internal disturbances when variying the parameters of the machine.
Linear modal analysis of Doubly-Fed Induction Generator (DFIG) torsional interaction: effect of DFIG controllers and system parameters
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Ziaei, Ali; Ghazi, Reza; Davarani, Roohalamin Zeinali
Clean energy sources like wind energy have received great attention due to growing demand for electrical energy and increase of environmental pollution. The Doubly Fed Induction Generators (DFIGs) are also in common use due to their ability to control the reactive power with no need for capacitor banks. Existence of active and reactive power controllers in DFIG may provide the possibility of adverse interaction with torsional modes of the turbine-generator set. Because of the importance of this phenomenon, in this paper, the interaction of DFIG controllers with other components of the wind turbine-generator, especially torsional modes, has been studied. As the variable speed wind turbine is used, the effects of rotor speed variation on the torsional interaction with the active and reactive power controllers have been investigated. Moreover, the effects of variation of other parameters such as local load, and mechanical and electrical parameters of DFIG on the torsional interaction have been studied. In order to study and analyze this phenomenon, the linear modal analysis is used. The obtained results demonstrate the effects of parameters in possible occurrence of interaction between the DFIG controllers and the DFIG turbine generator set. In addition, the obtained analytical results are verified via time domain simulation.
Perspective of buried oxide thickness variation on triple metal-gate (TMG) recessed-S/D FD-SOI MOSFET
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Priya, Anjali; Srivastava, Nilesh Anand; Mishra, Ram Awadh
Recently, Fully-Depleted Silicon on Insulator (FD-SOI) MOSFETs have been accepted as a favourable technology beyond nanometer nodes, and the technique of Recessed-Source/Drain (Re-S/D) has made it more immune in regards of various performance factors. However, the proper selection of Buried-Oxide (BOX) thickness is one of the major challenges in the design of FD-SOI based MOS devices in order to suppress the drain electric penetrations across the BOX interface efficiently. In this work, the effect of BOX thickness on the performance of TMG Re-S/D FD-SOI MOSFET has been presented at 60 nm gate length. The perspective of BOX thickness variation has been analysed on the basis of its surface potential profile and the extraction of the threshold voltage by performing two-dimensional numerical simulations. Moreover, to verify the short channel immunity, the impact of gate length scaling has also been discussed. It is found that the device attains two step-up potential profile with suppressed short channel effects. The outcomes reveal that the Drain Induced Barrier Lowering (DIBL) values are lower among conventional SOI MOSFETs. The device has been designed and simulated by using 2D numerical ATLAS Silvaco TCAD simulator.
GaInNAs/GaAs QW based structures to compensate parasitic effect of quantum-confined stark effect in photodetector applications
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Bielak, Katarzyna; Pucicki, Damian; Dawidowski, Wojciech; Badura, Mikołaj; Ściana, Beata; Tłaczała, Marek
The inhomogeneities of multicomponent semiconductor alloys, as well as phase segregation, can be utilized for enhancement of photodetector absorption properties and thus its efficiency. In this paper, the influence of external electric field on the probability of light absorption in the GaInNAs quantum well is discussed. Both phenomenon: indium and nitrogen composition gradient as well as step-like quantum well are applied to design the QW with compensation of the Quantum-Confined Stark Effect (QCSE) Parasitic effect of QCSE results from decrease of the wave functions overlapping in the QWs placed in reverse biased junction, which finally decrease the efficiency of the photodetector.
Potentiostatic electrodeposition of Cu2O under light and dark for photoelectrochemical hydrogen generation applications
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Mikolášek, Miroslav; Ondrejka, Peter; Chymo, Filip; Novák, Patrik; Harmatha, Ladislav; Řeháček, Vlastimil; Hotový, Ivan
Potentiostatic electrodeposition conducted at various deposition voltages from lactate-stabilized copper sulfate electrolyte was used for preparation of Cu2O layers for Photoelectrochemical (PEC) production of hydrogen. A novel approach based on an application of light during the electrodeposition is utilized to suppress the potential drop in the Cu2O layer during the potentiostatic deposition. Structures prepared under dark and light on an Ag substrate are analyzed by X-Ray Diffraction analysis (XRD), Scanning Electron Microscopy (SEM) and Linear Sweep Voltammetry (LSV). It was shown that the application of light increases the deposition rate due to the contribution of the photogenerated carriers. The deposition voltage affects the photoresponse of light deposited structures but causes only a negligible change in dark deposited structures. The light deposited samples exhibited a higher photoresponse for all deposition voltages. The presented study suggests the light potentiostatic electrodeposition as an attractive approach for the preparation of Cu2O structures for cheap and efficient photoelectrochemical water splitting applications.
System - level leakage power estimation model for ASIC designs
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Tripathi, Abhishek Narayan; Rajawat, Arvind
With advances in CMOS- technology and sub-micron process, leakage power dissipation has become a critical design metric. To incorporate more functions, designs are getting complex, thereby increases leakage power dissipation. Low power design objective requires early exploration and estimation. In this paper, we present the power estimation models for ASIC (Application Specific Integrated Circuit) based designs at the C-level of abstraction. The method includes analysis and extraction of the application specific information from the LLVM (Low-Level Virtual Machine) bit-code; which further applies to train the neural network. The trained model is applied in the estimation of the leakage power. Estimation of design power using our models is compared to the implemented measurement, which demonstrates its accuracy. In addition, the proposed methodology is significantly quicker and abolishes the need of synthesis based exploration.
Development and investigation of mathematical model of an optoelectronic sensor of methane concentration
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Vovna, Oleksandr Volodymyrovych; Laktionov, Ivan Serhiiovych; Zori, Anatolii Anatoliiovych; Akhmedov, Ramin Nizamiiovych
A mathematical model of a methane concentration sensor has been developed and studied, which takes into account the use of materials with different optical properties in the channel, spectral and spatial adjustment of the sensor components, losses at modulation and signal processing, as well as scattering and absorption of the optical emission flux in the channel. Taking into account results of modelling and experimental studies of the prototype sensor, confirming the adequacy of the proposed model, types of optoelectronic sensor components, as well as its design parameters with allowable deviations in manufacturing, have been substantiated and selected. The emission losses in the optical channel have been minimized when the informative parameter is maximized, which is absorption of optical emission by the measured methane concentration, by providing the length of the sensor measuring channel not more than 30 mm and the use of light and photodiodes with covering of their sensitive elements with chalcogenide glass. It has been established that the main measurement error of methane concentration with the application of these recommendations is not more than 0.04 vol.% with the regulated value of 0.20 vol.% in the range from 0 to 5 vol.%.
Optimization of nonuniform linear antenna array topology
(Vysoká škola báňská - Technická univerzita Ostrava, 2018) Tran, Xuan Luong; Veselý, Jiří; Dvořák, Filip
This paper deals with the use of a Nonuniform Linear Antenna array (NLA) for determining the Directions of Arrival (DOA) of a signal in 2450MHz frequency band. First, the principle of the DOA estimation method is described for the case of the MUSIC method. This paper also discusses the possibilities of optimizing the position of antenna elements in the NLA configuration, which are performed in analytical solutions and simulations. The simulation results are compared to the analytical results to obtain optimal NLA configurations for determining the signal DOA. Simulation results show that the probability of resolution and accuracy in determining the signal DOA are dependent on the antenna array aperture essentially. Furthermore, the realized NLA configuration was verified by an experimental measurement. The obtained experiment results demonstrate that the applied MUSIC method for NLA configuration is suitable and also highly accurate in determining the signal DOA, which was verified.

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