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Search results for: SINUSOIDAL PULSEWIDTH MODULATION
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Modulation of CYP19 expression by cabbage juices and their active components: indole-3-carbinol and 3,30-diindolylmethene in human breast epithelial cell lines
PublicationThe aim of this study was to evaluate the effect of white cabbage and sauerkraut juices of different origin and indole-3-carbinol (I3C) and diindolylmethane (DIM) on expression of CYP19 gene encoding aromatase, the key enzyme of estrogen synthesis.Remarkable differences in the effect on CYP19 transcript and protein level were found between the cab- bage juices (in 2.5-25 mL/L concentrations) and indoles (in 2.5-50 lM doses) in...
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Modulation of carcinogen metabolizing cytochromes p450 in rat liver and kidney by cabbage and sauerkraut juices: comparison with the effects of indole-3-carbinol and phenethyl isothiocyanate
PublicationThis study investigated the effect of raw cabbage and sauerkraut juices on the activity and expression of CYP1A1, 1A2, 1B1 and 2B in Wistar rat liver and kidney. The results were compared with those of two commercially available products of glucosinolates degradation: indole-3-carbinol (I3C) and phenethyl isothiocyanate (PEITC). Significant differences in the effect of the cabbage juices as well as I3C and PEITC between the liver...
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Modulation of the FeII spin crossover effect in the pentadecanuclear {Fe9[M(CN)8]6} (M = Re, W) clusters by facial coordination of tridentate polyamine ligands
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Increased cytotoxicity of an unusual DNA topoisomerase II inhibitor compound C-1305 toward HeLa cells with downregulated PARP-1 activity results from re-activation of the p53 pathway and modulation of mitotic checkpoints
PublicationOur previous studies have shown that murine fibroblast cells, in which PARP-1 gene was inactivated by gene disruption, are extremely sensitive to triazoloacridone compound C-1305, an inhibitor of DNA topoisomerase II with unusual properties. Here, we show that pharmacological inhibition of PARP-1 activity by its inhibitor compound NU1025, sensitizes human cervical carcinoma HeLa cells to compound C-1305 compared to treatment with...
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Five-phase induction motor drive with sine-wave filter
PublicationThe paper presents closed loop ac drive with 5 phase induction motor operating with voltage source inverter and sine wave filter. The motor supply voltages and currents have sinusoidal shape. For well known adjustable electric drives the field oriented control method with flux and speed co ntrol can be applied. In the presence of output filter both control and estimation algorithms should be modified due to sine wave filter installation....
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A new approach to active noise and vibration control - [Part II: unknown frequency case]
PublicationThis paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time stable linear plant with unknown and possibly timevarying dynamics. It is assumed that both the instantaneous frequency of the sinusoidal disturbance and its amplitude may be slowly varying with time and that the output signal is contaminated with wideband measurement noise. It is not assumed that a...
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System of protection against electric shock for circuits with power electronics converters
PublicationModern low voltage circuits are very often equipped with power electronics converters, therefore in these circuits non-sinusoidal earth currents (touch currents) may occur. For non-sinusoidal currents safety criteria should be modified. This paper presents these modified criteria and a computer system of protection against electric shock which can be implemented in circuits with power electronics converters. The system is based...
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Self-Optimizing Adaptive Vibration Controller
PublicationThis paper presents a new approach to rejection of sinusoidal disturbances acting at the output of a discrete-time linear stable plant with unknown dynamics. It is assumed that the frequency of the sinusoidal disturbance is known, and that the output signal is contaminated with wideband measurement noise. The proposed controller, called SONIC (self-optimizing narrowband interference canceller), combines the coefficient fixing technique,...
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A new approach to active noise and vibration control - [Part I: the known frequency case]
PublicationThis paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time stable linear plant with unknown dynamics. It is assumed that the frequency of the sinusoidal disturbance is known, and that the output signal is contaminated with wideband measurement noise. The disturbance rejection control rule is first derived and analyzed for a nominal plant model, different from...
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Multiple reference frame theory in the synchronous generator model considering harmonic distortions caused by nonuniform pole shoe saturation
PublicationThe paper describes a synchronous generator model developed based on the multiple reference frame theory. The main physical phenomena included in the model are the machine armature non-sinusoidal voltage waveform and the influence of armature current in load conditions on the armature voltage waveform higher harmonic components. The modified multiple reference frame theory model is proposed. In this modified theory model the field...
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Tripping of F-type RCDs for high-frequency residual currents
PublicationResidual current devices (RCDs) are apparatus commonly used for protection against electric shock in low-voltage electrical installations. They protect people in the case of an earth fault or even in the case of direct contact with the live parts. However, to be effective protective devices, RCDs have to detect residual currents of various waveform shapes which appear in modern electrical installations. For this purpose, RCDs are...
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Tripping of F-type RCDs for High-Frequency Residual Currents
PublicationResidual current devices (RCDs) are apparatus commonly used for protection against electric shock in low-voltage electrical installations. They protect people in the case of an earth fault or even in the case of direct contact with the live parts. However, to be effective protective devices, RCDs have to detect residual currents of various waveform shapes which appear in modern electrical installations. For this purpose, RCDs...
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Statistically efficient smoothing algorithm for time-varying frequency estimation
PublicationThe problem of extraction/elimination of a nonstationary sinusoidal signal from noisy measurements is considered. This problem is usually solved using adaptive notch filtering (ANF) algorithms. It is shown that the accuracy of frequency estimates can be significantly increased if the results obtained from ANF are backward-time filtered by an appropriately designed lowpass filter. The resulting adaptive notch smoothing (ANS) algorithm...
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SONIC - Self-optimizing narrowband interference canceler: comparison of two frequency tracking strategies
PublicationThis paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time linear stable plant with unknown and possibly time-varying dynamics. It is assumed that both the instantaneous frequency of the sinusoidal disturbance and its amplitude may be slowly varying with time and that the output signal is contaminated with wideband measurement noise. The proposed disturbance...
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Advances in CSI-fed induction motor drives
PublicationThe application of current source inverters (CSI)in induction motor (IM) drives offers a number of advantages,including: voltage boosting capability, natural shoot-throughshort-circuit protection and generation of sinusoidal voltages.The exact generation of sinusoidal voltages is possible thanks tothanks to the effect of the output ac filter capacitors and mayimprove the accuracy of sensorless IM control. The eliminationof high...
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Four Level Diode-Clamped Back-To-Back Converter with Active DC Link Voltage Control
PublicationThis article presents the design and control of 4L-DC back-to-back converter. To solve the DC link voltage balancing problem in four-level converter a new three-level double chopper topology based on PO-PWM modulation was designed and successfully tested. Also, the paper describes two phase space vector pulse width modulation 2P-SVPWM based on the shape function of finite elements. The control structure with modified Dead-Beat...
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An Extended Control of the Input Angle for Matrix Converters Connected with the Non-Unity Power Factor Loads.
PublicationThis paper proposes a novel PWM modulation algorithm for Multiphase Conventional Matrix Converters (MCMC), with 3 inputs and k outputs, using the transfer function of the load angle. The proposed approach extends the range of power angle control at the input during the operation with a maximum voltage transfer ratio. The proposed concept is based on the Direct Analytic Voltage PWM (DAV--PWM) modulation with an elliptical trajectory...
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Estimation of interior-permanent-magnet-synchronous-motor rotor position by analysis of phase-current derivatives
PublicationThis paper describes an algorithm for estimation of IPMSM rotor angular position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Calculation of the motor position is performed in every PWM cycle. The standard SV-PWM method is used to determine...
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Synchronous generator model taking into account the non-uniform saturation of the pole shoes
PublicationFor the evaluation of modern electric power systems with regard to their behavior, weight, and reliability a novel modeling and simulation tools have been developed. The paper presents circuit model of synchronous generator taking into account both the non-sinusoidal distribution of the stator and rotor winding, and non-uniform saturation of the pole shoes. This model is suitable for simulation of both salient and no-salient pole...
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Pomiary grubości cienkich warstw metodą modulacji chromatycznej.
PublicationTematem artykułu jest pomiar grubości struktur cienkowarstwowych szerokostosowanych w optoelektronice, transparentnych warstw dielektrycznych. Grubość jest najistotniejszym parametrem warstwy i determinuje jej właściwościoptyczne. Metoda pomiaru grubości cienkich warstw powinna być bezkontaktowa, nieniszcząca, niekosztowna oraz odporna na zakłócenia
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IPMSM rotor position estimator based on analysis of phase current derivatives
PublicationThis paper describes an algorithm for estimation of IPMSM angular rotor position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Algorithm is characterised by a very simple formulae. The calculation of rotor position is performed in every PWM...
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Fluctuation enhanced gas sensing with WO3-based nanoparticle gas sensors modulated by UV light at selected wavelengths
PublicationThe sensitivity and selectivity of WO3-based gas sensors can be enhanced by UV-irradiation-induced modulation, especially if different wavelengths are employed. We used fluctuation-enhanced gas sensing, based on measurements of resistance fluctuations in the gas sensor, to study the effects of such modulation on the noise intensity for ambient atmospheres of synthetic air without and with additions of small amounts of ethanol,...
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Multiple-channel frequency-adaptive active vibration control using SONIC
PublicationSONIC (self-optimizing narrowband interference canceller) is an acronym of a new approach to rejection of sinusoidal disturbances acting at the output of a discretetime stable linear plant with unknown and possibly timevarying dynamics. The paper presents two frequency-adaptive extensions of the multivariate SONIC algorithm. The efficacy of the proposed solutions is tested using our laboratory-scale active vibration control plant.
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Increasing the Utilization of dc-link Voltage of a Five-Leg VSI Based on Rotor Angle Control of Dual Induction Motors
PublicationThis paper introduces an increased utilization of the dc-link voltage of a five-leg voltage source inverter (VSI) based on the rotor flux angle control technique for dual induction motors, IM. The main purpose is to utilize additional abilities provided by a multi-motor drive system in limited operating conditions. Generally, a multi-motor drive system is widely used in electric vehicles (EVs), traction systems and in several industrial...
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A Simplified SVPWM Technique for Five-leg Inverter with Dual Three-phase Output
PublicationThis article proposes a simplified space vector pulse-width modulation (SVPWM) technique five-leg inverter with dual three-phase output. An idea to fed the dual tree-phase machine by the multiphase voltage source inverters (VSIs) is not new. Dual- and multi-motor drive systems are widely used in the industry applications. The most popular fields are: electric vehicles (EVs) and traction systems. Moreover, the specific characteristic...
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Multichannel self-optimizing active noise control scheme
PublicationThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of an unknown multivariable linear stable plant, is considered. The proposed cancellation scheme is a nontrivial extension of the SONIC (self-optimizing narrowband interference canceller) algorithm, developed earlier for single-input, single-output plants. In the important benchmark case - for disturbances with randomwalk-type amplitude...
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efficient fractional delay hilbert transform filter in the farrow structure
PublicationIn this paper the design and application of a Fractional Delay Hilbert Transform Filter (FDHTF) into an adaptive sub-sample delay estimation between two separated sinusoidal signals is considered. The FDHTF incorporates the functions of Hilbertian and variable fractional delay filtering of the incoming signal simultaneously, in one stage. In traditional approach each of these operations was performed separately. Obtained value...
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Multifrequency self-optimizing narrowband interference canceller
PublicationThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of a linear stable plant, is considered. It is assumed that disturbance is a multifrequency narrowband signal, and that system output is contaminated with wideband noise. It is not assumed that the reference signal is available. Two disturbance cancelling schemes are proposed, one for disturbances with unrelated frequency components, and...
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Application of Maximum Lenght Sequence in Silent Sonar
PublicationSilent sonars are designed to reduce the distance over which their sounding pulses can be detected by intercept sonars. In order to meet this objective, we can use periodical sounding signals that have low power, a very long duration and wide spectrum. If used in the silent sonar's receiver, matched filtration ensures very good detection of motionless or slow moving targets. However, it is more difficult to detect echo signals...
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High Efficiency Dual-Active-Bridge Converter with Triple-Phase-Shift Control for Battery Charger of Electric Vehicles
PublicationAn optimal modulation scheme with triple-phase-shift (TPS) control could increase the efficiency in the entire load range for a dual-active-bridge (DAB) converter under wide output voltage range conditions. Therefore, this study proposes a convergent approach to TPS mode selection, coupled with an optimal modulation scheme, ensuring the circuit’s efficiency over the entire range in the realm of a high-power and high-efficiency...
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Control strategy for the multilevel cascaded H-bridge converter
PublicationThe paper presents the control strategy for Cascaded H-bridge (CHB) converter . The converter output voltage using Space-Vector Pulse Width Modulation (SV-PWM) strategy is controlled. The DC-link voltages are controlled by appropriate choice of H-Bridges and appropriate choice of active and passive vectors.
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The influence of road surface unevenness on tyre rolling resistance
PublicationThe geometric characteristics of road surface substantially affect the interaction between tyre and road. Depending on pavement texture wavelength, the texture chiefly affects tyre/road friction, rolling resistance, interior and exterior noise, tyre wear, and ride comfort. The article presents results of investigations on the influence of road surface unevenness on the rolling resistance of passenger car and truck tyres. The tests...
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Cichy sonar - stan aktualny i perspektywy
PublicationW zastosowaniach militarnych często istnieje potrzeba prowadzenia obserwacji w sposób skryty za pomocą urządzeń emitujących sygnały trudne do przechwycenia przez przeciwnika. Rozwiązania stosowane w cichych radarach stanowiły punkt wyjścia do opracowania cichego sonaru. Prace nad projektem rozpoczęto na Politechnice Gdańskiej w roku 2010 w ramach Grantu NCBiR i są one dalej kontynuowane. W celu zachowania w cichym sonarze warunków...
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COMMENTS ON EXISTING ANALYTICAL SOLUTIONS TO THE WAVE-INDUCED CYCLIC RESPONSE OF A POROUS SEABED OF INFINITE THICKNESS
PublicationThis paper deals with the wave-induced cyclic response of a porous seabed (by means of oscillating parameters: pore-fluid pressure, soil displacement components, effective normal stress and shear stress components) due to a surface sinusoidal water-wave propagating over a seabed of infinite thickness. The main existing analytical solutions to the governing problem are critically discussed, pointing out their meaningful errors and...
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Study of Direct Methanol Fuel Cell Process Dynamics Using Dynamic Electrochemical Impedance Spectroscopy
PublicationA new technique, which was developed to characterize the direct methanol fuel cell under work conditions, has been presented in this paper. The impedance measurements were made using dynamic electrochemical impedance spectroscopy research technique in the galvanostatic mode, using multiple sinusoidal excitation. Obtained results show, that together with an increase of the temperature and working load, the global impedance...
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Series Passive Compensation of Common Mode Voltage in Multilevel Inverter Drives
PublicationThis paper presents an approach to the problem of a magnetic saturation of CM chokes that accompanies the method of passive compensation of a common mode (CM) voltage in an inverter drive system. Measurements have been provided in a drive system including multilevel inverters and the filter having sinusoidal output voltages and zero CM voltage. The theoretical analysis and experimental results show that the problem with magnetic...
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EMC disturbances in connection of driving system
PublicationIt is known the steep voltage changes caused by IGBT frequency inverters may cause some electromagnetic problems in driving system. Special dU/dt type as well as sinusoidal filters are used in order to limit the level of the disturbances. The paper presents investigation results of EMC disturbances in inverter supplied induction motor. Experiments have proved that disturbances in current connection differ essentially. Important...
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Generalized adaptive notch smoothing revisited
PublicationThe problem of identification of quasi-periodically varying dynamic systems is considered. This problem can be solved using generalized adaptive notch filtering (GANF) algorithms. It is shown that the accuracy of parameter estimates can be significantly increased if the results obtained from GANF are further processed using a cascade of appropriately designed filters. The resulting generalized adaptive notch smoothing (GANS) algorithm...
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On the instantaneous frequency smoothing for signals with quasi-linear frequency changes
PublicationThe problem of estimation of the slowly-varying instantaneous frequency of a nonstationary complex sinusoidal signal buried in noise is considered. This problem is usually solved using frequency tracking algorithms. It is shown that the accuracy of frequency estimates can be considerably increased if the results yielded by the frequency tracker are further processed using the appropriately designed filters. The resulting frequency...
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Reliable OFDM Data Transmission with Pilot Tones and Error-Correction Coding in Shallow Underwater Acoustic Channel
PublicationThe performance of Underwater Acoustic Communication (UAC) systems are strongly related to the specific propagation conditions of the underwater channel. Horizontal, shallow-water channels are characterised by extremely disadvantageous transmission properties, due to strong multipath propagation and refraction phenomena. The paper presents the results of communication tests performed during a shallow, inland-water experiment with...
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A new concept of PWM duty cycle computation using the Barycentric Coordinates in a Three-Dimensional voltage vectors arrangement
PublicationThe paper presents a novel approach to the Pulse Width Modulation (PWM) duty cycle computing for complex or irregular voltage vector arrangements in the two (2D) and three–dimensional (3D) Cartesian coordinate systems. The given vectors arrangement can be built using at least three vectors or collections with variable number of involved vectors (i.e. virtual vectors). Graphically, these vectors form a convex figure, in particular,...
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An improved frequency estimator for an adaptive active noise control scheme
PublicationAn improved frequency tracker is proposed for the recently introduced self optimizing narrowband interference canceller (SONIC). The scheme is designed for disturbances with quasi-linear frequency modulation and, under second-order Gaussian random-walk assumption, can be shown to be statistically efficient. One real-world experiment and several simulations show that a considerable improvement in disturbance rejection may be achieved...
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Detection of damages in a rivetted plate
PublicationThe paper presents the results of damage detection in a riveted aluminium plate. The detection method has been based on Lamb wave propagation. The plate has been analysed numerically and experimentally. Numerical calculations have been carried out by the use of the time-domain spectral finite element method, while for the experimental analysis laser scanning Doppler vibrometry (LSDV) has been utilised. The panel has been excited...
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A Method for Underwater Wireless Data Transmission in a Hydroacoustic Channel under NLOS Conditions
PublicationWireless data transmission in the hydroacoustic channel under non-line-of-sight (NLOS) propagation conditions, for example, during a wreck penetration, is difficult to implement reliably. This is mostly due to the multipath propagation, which causes a reduction in the quality of data reception. Therefore, in this work an attempt has been made to develop a reliable method of wireless underwater communication test it under the NLOS...
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Asynchronous Charge Carrier Injection in Perovskite Light-Emitting Transistors
PublicationUnbalanced mobility and injection of charge carriers in metal-halide perovskite light-emitting devices pose severe limitations to the efficiency and response time of the electroluminescence. Modulation of gate bias in methylammonium lead iodide light-emitting transistors has proven effective in increasing the brightness of light emission up to MHz frequencies. In this work, a new approach is developed to improve charge carrier...
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Kompleksowa analiza symulacyjna układu napędowego zespołu trakcyjnego
PublicationThe paper describes an approach to comprehensive analysis of traction electric drive. The drivetrain of ED-74 electric unit equipped with four inverter-fed induction motors was modeled in Matlab/Simulink. The model consists of functional blocks as: motors, inverters, drive controllers, filters. Structure and operation of the model was described. Chosen simulation results were presented and discussed. Two methods of modeling the...
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Emisyjność elektromagnetyczna przekształtników energoelektronicznych z modulacją rozproszoną
PublicationJednym z niepożądanych efektów ubocznych intensywnego rozwoju układów energoelektronicznych jest ich znaczna emisyjność elektromagnetyczna w zakresie zaburzeń przewodzonych i promieniowanych. Istnieje wiele metod ograniczania emisyjności tych układów, jednak ich skuteczność nie zawsze jest wystarczająca do spełnienia wymagań związanych z kompatybilnością elektromagnetyczna. W pracy zaprezentowano wyniki pomiarów skuteczności ograniczania...
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Research and analysis of high-speed data transmission radio link designed for maritime environment
PublicationIn these article the realization of digital radio link for high-speed data transmission was presented. Its concept and practical realization, using USRP devices from National Instruments, were described. Developed software for generation and reception of digital signals in baseband, including description of modulation types, and time and frequency synchronization mechanisms, was presented. Moreover, an operation of designed radio...
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Research and Analysis of High-Speed Data Transmission Radio Link Designed for Maritime Environment
PublicationIn these article, the realization of digital radio link for high-speed data transmission was presented. Its concept and practical realization, using USRP devices from National Instruments, were described. Developed software for generation and reception of digital signals in baseband, including description of modulation types, and time and frequency synchronization mechanisms, was presented. Moreover, an operation of designed radio...
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Ordinal Pattern Statistics for RR Intervals during Head-Up Tilt Test in Patients with the History of Vasovagal Syncope
PublicationWe apply ordinal pattern analysis to quantify differences in distribution of patterns of length 3 and 4 in basal state and during head-up tilt test (HUTT) in patients with the history of syncope and positive (HUTT(+)) or negative (HUTT(-)) responses to the test. We identify the patterns related to prevalence of sympathetic or parasympathetic cardiac modulation as well as describe the relations between the response to the test and...