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Wyniki wyszukiwania dla: high frequency power converter
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Detection and Direction-of-Arrival Estimation of Weak Spread Spectrum Signals Received with Antenna Array
PublikacjaThis paper presents a method for the joint detection and direction of arrival (DOA) estimation of low probability of detection (LPD) signals. The proposed approach is based on using the antenna array to receive spread-spectrum signals hidden below the noise floor. Array processing exploits the spatial correlation between phase-delayed copies of the signal and allows us to evaluate the parameter used to make the decision about the...
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Acceleration of Electromagnetic Simulations on Reconfigurable FPGA Card
PublikacjaIn this contribution, the hardware acceleration of electromagnetic simulations on the reconfigurable field-programmable-gate-array (FPGA) card is presented. In the developed implementation of scientific computations, the matrix-assembly phase of the method of moments (MoM) is accelerated on the Xilinx Alveo U200 card. The computational method involves discretization of the frequency-domain mixed potential integral equation using...
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Plasma-Based Deposition and Processing Techniques for Optical Fiber Sensing
PublikacjaPlasma-based techniques are widely applied for well-controlled deposition, etching or surface functionalization of a number of materials. It is difficult to imagine fabrication of novel microelectronic and optoelectronic devices without using plasma-enhanced deposition of thin films, their selective etching or functionalization of their surfaces for subsequent selective binding of chemical or biological molecules. Depending on...
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Electric shock hazard in circuits with variable-speed drives
PublikacjaThe conventional approach to electrical safety under fault condition in typical power systems considers earth fault currents of sinusoidal waveform and frequency of 50/60 Hz. However, in circuits with variable-speed drives, there is earth fault current flow with harmonics, and these harmonics influence the threshold of ventricular fibrillation. The paper presents earth fault current waveforms in circuits with variable-speed drives...
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Improved Efficacy Behavioral Modeling of Microwave Circuits through Dimensionality Reduction and Fast Global Sensitivity Analysis
PublikacjaBehavioral models have garnered significant interest in the realm of high-frequency electronics. Their primary function is to substitute costly computational tools, notably electromagnetic (EM) analysis, for repetitive evaluations of the structure under consideration. These evaluations are often necessary for tasks like parameter tuning, statistical analysis, or multi-criterial design. However, constructing reliable surrogate models...
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Error analysis of calculating average d-q current components using Regular Sampling and Park transformation in FOC drives
PublikacjaIn electric drives using voltage source inverters, motor currents contain ripple component resulting from pulse-width modulated (PWM) voltage. The frequency range of the ripples is much higher than the bandwidth of current control. Therefore the control is performed on the basis of a fundamental current component, i.e. average value with the averaging time being the PWM period. In majority of cases the average current is measured...
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Optimization of the Aeration Strategies in a Deammonification Sequencing Batch Reactor for Efficient Nitrogen Removal and Mitigation of N2O Production
PublikacjaIn deammonification systems, nitrite-oxidizing bacteria (NOB) suppression and nitrous oxide (N2O) mitigation are two important operational objectives. To carry out this multivariable analysis of response, a comprehensive model for the N cycle was developed and evaluated against experimental data from a laboratory-scale deammonification granular sludge sequencing batch reactor. Different aeration strategies were tested, and the manipulated...
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DESIGN ANALYSIS OF HYBRID GAS TURBINE - FUEL CELL POWER PLANT IN STATIONARY AND MARINE APPLICATIONS
PublikacjaThe paper concerns design analysis of a hybrid gas turbine power plant with a fuel cell (stack). The aim of this work was to find the most favorable variant of the medium capacity (approximately 50 MW) hybrid system. In the article, computational analysis of two variants of such a system was carried out. The analysis let to calculate capacity, efficiency of both variants and other parameters like flu gas temperature. The paper...
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The Influent Effects of Flow Rate Profile on thePerformance of Microbial Fuel Cells Model
PublikacjaThe energy contained in wastewaters has been identified as a promising sustainableenergy resource that could be harvested by using microbial fuel cells (MFC). When dealing with realwastewaters, the MFCs should be able to manage high flow rates and flow rates fluctuations. In thiswork, the short-term effects of the influent flow rate variations on the performance of a microbialfuel cell has been studied. With this aim, the influent...
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an intelligent image processing sensor - the algorithm and the hardware implementation
PublikacjaW artykule przedstawiono algorytm przeznaczony do rozpoznawania obiektów ruchomych w obrazie do celu analizy ruchu pojazdów. Algorytm został zrealizowany w układzie FPGA.Ang.: This paper describes the idea and theimplementation of the robust algorithm dedicated toextraction of moving vehicles from real-time cameraimages for the evaluation of traffic parameters, suchas the number of vehicles, their direction of movementand their...
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Comparative study of a bottoming SRC and ORC for Joule–Brayton cycle cooling modular HTR exergy losses, fluid-flow machinery main dimensions, and partial loads
PublikacjaEnergy conversion efficiency increase in power plants with high-temperature gas-cooled reactors via implementation of the bottoming cycle was investigated under nominal and minimal thermal load of a high-temperature reactor (HTR). Heat transfer surface area and turbine outlet volumetric flow rate in bottoming cycles was also investigated. Water and two low-boiling point working fluids (ammonia and ethanol) were analyzed. Analyzed...
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Low-cost multiband four-port phased array antenna for sub-6 GHz 5G applications with enhanced gain methodology in Radio-over-fiber systems using modulation instability
PublikacjaPhased array antenna (PAA) technology is essential for applications requiring high gain and wide bandwidth, such as sensors, medical, and 5G. Achieving such a design, however, is a challenging and intricate process that calls for precise calculations and a combination of findings to alter the phase and amplitude of each unit. Furthermore, coupling effects between these PAA structure elements can only be completed with the use of...
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Composite Materials Based on Polymer-Derived SiCN Ceramic and Disordered Hard Carbons as Anodes for Lithium-Ion Batteries
PublikacjaNew composite materials based on polymer-derived SiCN ceramics and hard carbons were studied in view of its application as anodes for lithium-ion batteries. Two kinds of composites were prepared by pyrolysis of the preceramic polysilazane (HTT1800, Clariant) at 1000 °C in Ar atmosphere mixed with hard carbons derived from potato starch (HC_PS) or with a hard carbon precursor, namely potato starch (PS), denoted as HTT/HC_PS and...
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Investigations of Energy Conversion and Surface Effect for Laser-Illuminated Gold Nanorod Platforms
PublikacjaAchieving a quick temperature increase is a burning issue for biophysical applications, like germ inactivation and tumor ablation, and for energy performances, like solar collectors and steam generators. Based on the plasmon resonance phenomenon, noble metallic nanoparticles have emerged as promising weapons due to their very high biocompatibility, optical properties, and high surface-to-volume ratio, increasing energy conversion...
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Chemical composition of tellurium oxides thin films deposited by magnetron sputtering method
Dane BadawczeThin films were prepared by radio frequency reactive magnetron sputtering technique. Metallic Te target was sputtered for about 45 min in argon-oxygen atmosphere what resulted in 300 nm film thickness deposition. The pressure in the chamber was below 0.2 Pa and substrate was heated at 200 °C. The distance between sputtered target and the Corning 1737...
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Vision-based parking lot occupancy evaluation system using 2D separable discrete wavelet transform
PublikacjaA simple system for rough estimation of the occupancy of an ad-hoc organized parking lot is presented. A reasonably simple microprocessor hardware with a low resolution monochrome video camera observing the parking lot from the location high above the parking surface is capable of running the proposed 2-D separable discrete wavelet transform (DWT)-based algorithm, reporting the percentage of the observed parking area occupied by...
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Identification and antimicrobial resistance of Enterococcus spp. isolated from surface water
PublikacjaIn the study species distributions and antimicrobial resistance profiles were determined among riverine Enterococcus spp. Susceptibility of the isolates was tested against: ampicillin, imipenem, teicoplanin, vancomycin, erythromycin, linezolid, fosfomycin, ciprofloxacin,levofloxacin, moxifloxacin, tetracycline, high levels of gentamicin and streptomycin. The enterococci were detected in all of the analyzed water samples, periodically...
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Detection of People Swimming in Water Reservoirs with the Use of Multimodal Imaging and Machine Learning
PublikacjaEvery year in many countries, there are fatal unintentional drownings in different water reservoirs like swimming pools, lakes, seas, or oceans. The existing threats of this type require creating a method that could automatically supervise such places to increase the safety of bathers. This work aimed to create methods and prototype solutions for detecting people bathing in water reservoirs using a multimodal imaging system and...
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Images of the Seabed of the Gulf of Gdansk Obtained by Means of the Parametric Sonar
PublikacjaThe main goal of this paper is to present results of the experimental investigation of the seabed by means of parametric echosounder in the form of chosen images. The phenomena of nonlinear interaction between two parallel beams of high intensity gives as a results very narrow beam of low frequency wave, that enables to penetrate the sea bottom. The first step of our investigations was calibration of all the elements of the measuring...
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Detection of Objects Buried in the Sea Bottom with the Use of Parametric Echosounder
PublikacjaThe paper contains results of a in situ research main task of which was to detect objects buried, partially or completely, in the sea bottom. Object detecting technologies employing acoustic wave sources based on nonlinear interaction of elastic waves require application of parametric sound sources. Detection of objects buried in the sea bottom with the use of classic hydroacoustic devices such as the sidescan sonar or multibeam...
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Low-cost EM-Simulation-based Multi-objective Design Optimization of Miniaturized Microwave Structures
PublikacjaIn this work, a simple yet reliable technique for fast multi-objective design optimization of miniaturized microwave structures is discussed. The proposed methodology is based on point-by-point identification of a Pareto-optimal set of designs representing the best possible trade-offs between conflicting objectives such as electrical performance parameters as well as the size of the structure of interest. For the sake of computational...
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Rapid EM-driven antenna dimension scaling through inverse modeling
PublikacjaIn this letter, a computationally feasible technique for dimension scaling of antenna structures is introduced. The proposed methodology is based on inverse surrogate modeling where the geometry parameters of the antenna structure of interest are explicitly related to the operating frequency. The surrogate model is identified based on a few antenna designs optimized for selected reference frequencies. For the sake of computational...
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Angle Tracking Observer for Filtering Rotor Position Estimates in Sensorless Electric Drives
PublikacjaSensorless electric drives use measurements of electrical quantities to estimate rotor position and speed. Measurement errors deteriorate the estimation accuracy, thus additional means are necessary to remove high-frequency components from estimated signals. This paper proposes to use an Angle Tracking Observer (ATO) for reducing noise in rotor position estimates, which is related to random errors in the measurements. A simplified,...
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Convenient and efficient N-methylation of secondary amines under solvent-free ball milling conditions
PublikacjaIn the present work, we report the development of a rapid, efcient, and solvent-free procedure for the N-methylation of secondary amines under mechanochemical conditions. After optimization of the milling parameters, a vibrational ball mill was used to synthesize 26 tertiary N-methylated amine derivatives in a short time of 20 min (30 Hz frequency) and high yields ranging from 78 to 95%. An exception was compounds having a hydroxyl...
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Modelling of elastic wave propagation in a bolted joint using a thin layer of shell elements
PublikacjaThere are many mathematical models describing the propagation of elastic waves through the imperfect boundary of two media. They were successfully applied to modelling of high frequency bulk waves and their interaction with local defects. On the other hand, the existing literature models of bolted connections ignore the aspect of imperfect connection between elements. Therefore, this paper presents the concept of application of...
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Spectroscopic study of atmospheric pressure 915 MHz microwave plasma at high argon flow rate
PublikacjaIn this paper results of optical emission spectroscopic (OES) study of atmospheric pressure microwave 915 MHz argon plasma are presented. The plasma was generated in microwave plasma source (MPS) cavity- resonant type. The aim of research was determination of electron excitation temperature Texc gas temperature Tg and electron number density ne. All experimental tests were performed with a gas flow rate of 100 and 200 l/min and...
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A new assay for the simultaneous identification and differentiation of Klebsiella oxytoca strains.
PublikacjaKlebsiella oxytoca is the second most frequently identified species of Klebsiella isolated from hospitalized patients. Klebsiella spp. is difficult to identify using conventional methods and is often misclassified in clinical microbiology laboratories. K. oxytoca is responsible for an increasing number of multi-resistant infections in hospitals because of insufficient detection and identification. In this study, we propose a new...
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Knowledge Sharing and Organizational Culture Dimensions: Does Job Satisfaction Matter?
PublikacjaThe aim of this study is to examine how job satisfaction influences the relationship between company performance, knowledge sharing, and organizational culture, perceived through the prism of Hofstede’s cultural dimensions, controlled by company size and staff position. A survey of 910 Polish employees (mainly knowledge workers) with different roles and experiences across different industries was conducted. The data were analyzed...
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Low-Voltage Low-Power Filters with Independent ω0 and Q Tuning for Electronic Cochlea Applications
PublikacjaAn acoustic second-order low-pass filter is proposed for filter banks emulating the operation of a human cochlea. By using a special filter structure and an innovative quality (Q)-factor tuning technique, an independent change of the cutoff frequency (ω0) and the Q-factor with unchanged gain at low frequencies is achieved in this filter. The techniques applied result in a simple filter design with low Q-factor sensitivity to component...
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Advances and Trends in Non-Conventional, Abrasive and Precision Machining 2021
PublikacjaIn the modern, rapidly evolving industrial landscape, the quest for machining and production processes consistently delivering superior quality and precision is more pronounced than ever. This necessity and imperative are driven by the increasing complexity in the design and manufacturing of mechanical components, an evolution in lockstep with the swift advancements in material science. The real challenge of this evolution lies...
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Neural oscillations induced by IAPS pictures (session 17)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 22)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 15)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 21)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 20)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 12)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 18)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 14)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 13)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 16)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 19)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Optical Parameters Stability Over Time of Porous Phantoms Mimicking Tissues
Dane BadawczeOptical phantoms are used to validate optical measurement methods. The stability of their optical parameters over time allows them to be used and stored over long-term periods while maintaining their optical parameters. The aim of the presented research was to investigate the stability of fabricated porous phantoms, which can be used as a lung phantom...
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Neural oscillations induced by IAPS pictures (session 10)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 1)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 9)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 5)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 2)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 11)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 3)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...
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Neural oscillations induced by IAPS pictures (session 6)
Dane BadawczeThe data were collected to perform research on the possibility of controlling the content displayed on the monitor screen using human emotional states extracted from EEG signals. The dataset contains recordings of 14-channel EEG signals gathered from seven persons aged 23 - 35 within 26 sessions, during which 45 different random photos, taken from the...