displaying 1000 best results Help
Search results for: SINE-WAVE FILTER
-
N-point estimators of the Instantaneous Complex Frequency
PublicationIn this paper estimators of the instantaneous complex frequency (ICF) are presented and discussed. The differential approach for the estimation of the ICF is used, therefore the estimators are based on maximally flat N-point FIR filters: differential and delay. The investigation of the filter performance includes static characteristics of ICF estimation and the error of the ICF estimation in the discrete frequency domain.W pracy...
-
GPU-Accelerated 3D Mesh Deformation for Optimization Based on the Finite Element Method
PublicationThis paper discusses a strategy for speeding up the mesh deformation process in the design-byoptimization of high-frequency components involving electromagnetic field simulations using the 3D finite element method (FEM). The mesh deformation is assumed to be described by a linear elasticity model of a rigid body; therefore, each time the shape of the device is changed, an auxiliary elasticity finite-element problem must be solved....
-
Emotion monitoring system for drivers
PublicationThis article describes a new approach to the issue of building a driver monitoring system. Actual systems focus, for example, on tracking eyelid and eyebrow movements that result from fatigue. We propose a different approach based on monitoring the state of emotions. Such a system assumes that by using the emotion model based on our own concept, referred to as the reverse Plutchik’s paraboloid of emotions, the recognition of emotions...
-
Enhancing rheological muscle models with stochastic processes
PublicationPurpose: Biological musculoskeletal systems operate under variable conditions. Muscle stiffness, activation signals, and loads change during each movement. The presence of noise and different harmonic components in force production significantly influences the behaviour of the muscular system. Therefore, it is essential to consider these factors in numerical simulations. Methods: This study aims to develop a rheological mathematical...
-
Time-domine Dipole Fields in acoustic and Elektromagnetics
PublicationThe ultrawideband (UWB) radio technique presents a challenge not just for technology. The UWB carrier-free pulses act at a close distance, their electromagnetic fields being very different from classic monochromatic plane wave. The author proposes to adapt a time-domian approach to analysis of broadband spherical fields, both acoustic and electromagnetic, in fundamental cases of quasi-point physical sources.
-
MAGNETOACOUSTIC HEATING AND STREAMING IN A PLASMA WITH FINITE ELECTRICAL CONDUCTIVITY
PublicationNonlinear effects of planar and quasi-planar magnetosound perturbations are discussed. Plasma is assumed to be an ideal gas with a finite electrical conductivity permeated by a magnetic filed orthogonal to the trajectories of gas particles. the excitation of non-wave modes in the filed of intense magnetoacoustic perturbations, i.e., magnetoaciustic heating and streaming, is discussed. The analysis includes a derivation if instantaneous...
-
Prądy łożyskowe w układach napędowych z silnikami indukcyjnymi
PublicationW pracy przedstawiono problemy występujące w układach napędowych z silnikami indukcyjnymi zasilanymi z falownika napięcia. Zwrócono uwagę na rosnącą liczbę uszkodzeń silników w napędach przekształtnikowych. Wskazano przyczyny wynikające z charakteru zasilania przekształtnikowego silnika. Główną uwagę poświęcono prądowi łożyskowemu, który odpowiada za większość awarii maszyn. Przedstawiono rodzaje prądów łożyskowych, wyjaśniając...
-
Predykcyjne sterowanie równoległym filtrem aktywnym ze sprzężeniem od prądu zasilającego
PublicationArtykuł przedstawia nowatorską strategię predykcyjnego sterowania równoległym energetycznym filtrem aktywnym (EFA). Proponowane sterowanie zawiera sprzężenie zwrotne od prądu zasilającego i wiąże zalety sterowania w układzie otwartym oraz zamkniętym – szybkość reakcji na zmianę prądu odbioru i bardzo wysoką skuteczność kompensacji. Wysoka jakość prądu kompensacyjnego wynika również z zastosowania w sterowaniu algorytmów predykcyjnych,...
-
Development of Intelligent Control for Annealing Unit to Ensure the Minimization of Retroactive Effects on the Supply Network
PublicationResearch conducted by our team focused on the development of a complete annealing unit, using modern technologies and components, such as a programmable logic controller, an industrial computer and microcontrollers, ensuring an intelligent way to control power semiconductor elements (SSR relays), with regard to minimizing retroactive effects on the supply network. This modern configuration offers a number of new possibilities of...
-
Multi-state multi-reference Møller-Plesset second-order perturbation theory for molecular calculations
PublicationThis work presents multi‐state multi‐reference Møller–Plesset second‐order perturbation theory as a variant of multi‐reference perturbation theory to treat electron correlation in molecules. An effective Hamiltonian is constructed from the first‐order wave operator to treat several strongly interacting electronic states simultaneously. The wave operator is obtained by solving the generalized Bloch equation within the first‐order...
-
Balance errors generated by numerical diffusion in the solution of non-linear open channel flow equations
PublicationThe paper concerns the untypical aspect of application of the dissipative numerical methods to solve nonlinear hyperbolic partial differential equations used in open channel hydraulics. It is shown that in some cases the numerical diffusion generated by the applied method of solution produces not only inaccurate solution but as well as a balance error. This error may occur even for an equation written in the conservative form not...
-
Numerical Simulation of Catastrophic Flood: the Case Study of Hypothetical Failure of the Bielkowo Hydro–Power Plant Reservoir
PublicationThe numerical modeling of flood wave propagation following the hypo-thetical breaks of the embankments of the Bielkowo hydro–power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland have been presented. The results of computations were used to estimate the parameters of the flood waves, which are indispensable for the flood zone determination and mapping and then for the flood risk analysis. When estimating...
-
Integrated Application of GPR and Ultrasonic Testing in the Diagnostics of a Historical Floor
PublicationThe paper presents the results of integrated ground penetrating radar (GPR) and ultrasonic testing (UT) measurements conducted on a historical floor in St. Nicholas’ Church, Gdańsk, Poland. The described inspection was the first stage of the technical state assessment of the building. The aim of the study was the detection of underfloor air gaps, which were observed in a few trial pits. The condition of the ground under the floor...
-
Detection and Imaging of Debonding in Adhesive Joints of Concrete Beams Strengthened with Steel Plates Using Guided Waves and Weighted Root Mean Square
PublicationStrengthening of engineering structures is an important issue, especially for elements subjected to variable loads. In the case of concrete beams or slabs, one of the most popular approaches assumes mounting an external reinforcement in the form of steel or composite elements by structural adhesives. A significant disadvantage of adhesive joints is the lack of access to the adhesive film for visual condition assessment, thus, there...
-
A XAS study of a highly diluted Pt electrocatalyst operating in PEM fuel cells
PublicationWe present an X-ray absorption spectroscopy (XAS) study of a low Pt content catalyst layer(Pt loading 0.1 mg c2) operating at the cathode of a proton exchange membrane fuel cell(PEMFC). This catalyst is based on the use of a mesoporous inorganic matrix as a support forthe catalyst Pt nanoparticles. Due to the high Pt dilution, in situ measurements of itsstructural properties by XAS are challenging and suitable experimental strategies...
-
On tracking properties of real-valued generalized adaptive notch filters
PublicationGeneralized adaptive notch filters (GANFs) are used for identification/tracking of quasi-periodically varying dynamic systems and can be considered an extension, to the system case, of classical adaptive notch filters. The paper presents results of local performance analysis of a real-valued GANF algorithm, i.e., algorithm designed to track parameters of a real-valued system. This is an extension of the previous work which focused...
-
Integration of inertial sensors and GPS system data for underwater navigation
PublicationThe Inertial Navigation System (INS) is usually employed to determine the position of an underwater vehicles, like Remotely Operated Vehicles (ROV) and, more recently, Autonomous Underwater Vehicle (AUV). The accuracy of the position provided by the INS, which uses accelerometers and gyroscopes, deteriorates with time. An external aiding sources such as the Global Positioning System (GPS) can be employed to reduce the error growth...
-
Temperature Impact of Nitrogen Transformation in Technological System: Vertical Flow Constructed Wetland and Polishing Pond
PublicationThe article describes the results of the research, purpose of which was to evaluate influence of the temperature on the effectiveness of nitrification and denitrification in the sewage treatment system consisting of vertical flow constructed wetland and polishing pond. During the analysed period, the efficiency of removing total nitrogen was low and amounted to 12.7%. In the polishing pond in the summer period, content of total...
-
Self-refraction of acoustic pulses with shock fronts in some nonequilibrium media
PublicationThe nonlinear self-refraction of acoustic pulsed beams, which include shock fronts, is studied. The medium of sound propagation is a gas where thermodynamically nonequilibrium processes take place, such as exothermic chemical reaction or excitation of vibrational degrees of a molecule’s freedom. Comparative analysis of the features of sound propagation over gases where pure nonlinear attenuation of the shock wave occurs, and gases...
-
Broadside coupled stripline with double-side UC-PBG structure
PublicationRozważono strukturę linii paskowych sprzężonych szerokim bokiem z periodycznie zaburzoną metalizacją masy typu UC-PBG (Uniplanar Compact - Photonic BandGap). W celu oceny przydatności struktury zaprojektowano, wykonano i przebadano sprzęgacz 3dB. Potwierdzono przewidywany efekt spowolnienia fali (slow wave effect), którego konsekwencją jest możliwość znacznej redukcji wymiarów układu.
-
Control System Design for Dynamic Positioning using Vectorial Backstepping
PublicationThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. The computer simulation results were given to...
-
NON-STATIONARY THERMAL SELF-ACTION OF ACOUSTIC BEAMS CONTAINING SHOCK FRONTS IN THERMOCONDUCTING FLUID
PublicationNon-stationary thermal self-action of a periodic or impulse acoustic beam containing shock fronts in a thermoconducting Newtonian fluid is studied. Self-focusing of a saw-tooth periodic and impulse sound is considered, as well as that of a solitary shock wave which propagates with the linear sound speed. The governing equations of the beam radius are derived. Numerical simulations reveal that the thermal conductivity weakens the...
-
Measurements of the mechanical system properties of "SpeedLine magnetic" ultra-fast robot prototype for IML labeling
Open Research DataThe mechanical system tests of the high-speed IML labeling robot "SpeedLine Magnetic" were carried out in order to analyze the effects of the drive system's operating parameters on vibration and noise.
-
Nadmiarowe zgony podczas pandemii COVID-19 w Polsce i ocena skuteczności szczepień
PublicationZ powodu pandemii COVID-19 zmarły miliony ludzi na całym świecie. Jak wynika z wielu badań, szczepienia przeciw chorobie wywołanej wirusem SARS-CoV-2 okazały się środ-kiem ograniczającym skalę zachorowań i liczbę zgonów. Celem badania omawianego w artyku-le jest pomiar skali pandemii w Polsce za pomocą liczby nadmiarowych zgonów w podregio-nach według klasyfikacji NUTS 3 i w grupach wieku, a następnie określenie zależności pomiędzy...
-
Hierarchical Estimation of Human Upper Body Based on 2D Observation Utilizing Evolutionary Programming and 'Genetic Memory'
PublicationNew method of the human body pose estimation based on single camera 2D observation is presented. It employs 3D model of the human body, and genetic algorithm combined with annealed particle filter for searching the global optimum of model state, best matching the object's 2D observation. Additionally, motion cost metric is employed, considering current pose and history of the body movement, favouring the estimates with the lowest...
-
Automatic Optimization Of Adaptive Notch Filter’s Frequency Tracking
PublicationEstimation of instantaneous frequency of narrowband com- plex sinusoids is often performed using lightweight algo- rithms called adaptive notch filters. However, to reach high performance, these algorithms require careful tuning. The paper proposes a novel self-tuning layer for a recently intr o- ducedadaptive notch filtering algorithm. Analysis shows th at, under Gaussian random-walk type assumptions, the resultin g solution converges...
-
AUTOMATIC OPTIMIZATION OF ADAPTIVE NOTCH FILTER’S FREQUEN CY TRACKING
PublicationEstimation of instantaneous frequency of narrowband com- plex sinusoids is often performed using lightweight algo- rithms called adaptive notch filters. However, to reach high performance, these algorithms require careful tuning. The paper proposes a novel self-tuning layer for a recently intr o- ducedadaptive notch filtering algorithm. Analysis shows th at, under Gaussian random-walk type assumptions, the resultin g solution converges...
-
DETERMINATION OF SP3 FRACTION IN ta-C COATING USING XPS AND RAMAN SPECTROSCOPY
PublicationThe paper presents results of studies on the structure of tetrahedral amorphous carbon films (ta-C) with a thickness in the range from 20 to 280 nm, deposited using pulsed vacuum arc technique with an electromagnetic Venetian blind plasma filter. The results of the phase structure analysis, obtained using visible Raman spectroscopy and UV Raman spectroscopy methods, showed a strong dependence of the results on the presence, on...
-
Measurement method for capacitive sensors for microcontrollers based on a phase shifter
PublicationA complete measurement method dedicated to capacitive sensors has been developed. It includes the development of hardware (an analogue interface circuit for microcontrollers with built-in times/counters and analogue comparators) and software (a measurement procedure and a systematic error calibration (correction) algorithm which is based on a calibration dictionary). The interface circuit consists of a low-pass filter and a phase...
-
Posttraumatic Orbital Emphysema: A Numerical Model
PublicationOrbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture) of the deformations of the inferior orbital wall after a strike in...
-
Efficient Gradient-Based Algorithm with Numerical Derivatives for Expedited Optimization of Multi-Parameter Miniaturized Impedance Matching Transformers
PublicationFull-wave electromagnetic (EM) simulation tools have become ubiquitous in the design of microwave components. In some cases, e.g., miniaturized microstrip components, EM analysis is mandatory due to considera¬ble cross-coupling effects that cannot be accounted for otherwise (e.g., by means of equivalent circuits). These effects are particularly pronounced in the structures in¬volving slow-wave compact cells and their numerical...
-
Magnetic switching of Kerker scattering in spherical microresonators
PublicationMagneto-optical materials have become a key tool in functional nanophotonics, mainly due to their ability to offer active tuning between two different operational states in subwavelength structures. In the long-wavelength limit, such states may be considered as the directional forward- and back-scattering operations, due to the interplay between magnetic and electric dipolar modes, which act as equivalent Huygens sources. In this...
-
A procedure for the identification of effective mechanical parameters of additively manufactured elements using integrated ultrasonic bulk and guided waves
PublicationThe subject of the current work was a simple but robust novel two-stage procedure for the non-destructive determination of effective elastic constants using ultrasonic wave propagation. First, ultrasonic bulk wave velocities measured on cubic samples were used to calculate most of the elements of the stiffness matrix. Secondly, the remaining elements were determined using the dispersion curves of elastic guided waves measured on...
-
An Analysis of Multistrip Line Configuration on Elliptical Cylinder
PublicationA configuration of multistrip lines mounted on a multilayer dielectric coated elliptic cylinder is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. Both open and shielded lines are considered in the analysis. Propagation coefficients and characteristic impedances are calculated for the...
-
The Dynamical Projectors Method Hydro and Electrodynamics
PublicationThe dynamical projectors method proves to reduce a multicomponent problem to the simplest one-component problem with its solution determined by specific initial or boundary conditions. Its universality and application in many different physical problems make it particularly useful in hydrodynamics, electrodynamics, plasma physics, and boundary layer problems. A great variety of underlying mechanisms are included making this book...
-
An Analysis of Cylindrical Posts of Arbitrary Convex Cross Sections Located in Waveguide Junctions with the Use of Field Matching Method
PublicationA problem of electromagnetic wave scattering from cylindrical posts of arbitrary cross section located in waveguide junction is presented. The method of analysis is based on the direct field matching technique. Multimode scattering matrices of every section of waveguide junction are calculated and cascading procedure is utilized to investigate the whole structure. The results are verified by comparing them with those obtained from...
-
Application of the laser diode with central wavelength 975 nm for the therapy of neurofibroma and hemangiomas
PublicationThis paper presents newly developed dermatological laser (with central wavelength 975 nm) for application in therapies requiring deep penetration of tissue, e.g. cutaneous (dermal) neurofibroma (Recklinghausen disease) and hemangiomas. This laser can work either in pulse or continues wave mode. Laser radiation is transmitted toward the application region by optical fiber with a diameter of 0.6 mm. The compact design of the laser...
-
Spurious Modes in Model Order Reduction in Variational Problems in Electromagnetics
PublicationIn this work, we address an everlasting issue in 2 model order reduction (MOR) in electromagnetics that has 3 remained unnoticed until now. Contrary to what has been 4 previously done, we identify for the very first time spurious 5 modes in MOR for time-harmonic Maxwell’s equations and 6 propose a methodology to remove their negative influence on the 7 reduced order model (ROM) response. These spurious modes 8 have nonzero resonance...
-
Power of the low alpha brainwaves in the mental imagery experiment in sport: the "Your Home Venue" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The study's main aim was to examine the cortical correlations of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with the...
-
Power of the low alpha brainwaves in the mental imagery experiment in sport: the "Slow Start" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The main aim of the study was to examine the cortical correlates of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with...
-
Power of the SMR brainwaves in the mental imagery experiment in sport: the "Start in High Level Championship" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The main aim of the study was to examine the cortical correlates of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with...
-
Power of the low alpha brainwaves in the mental imagery experiment in sport: the "Successful Competition" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The study's main aim was to examine the cortical correlations of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with the...
-
Power of the high alpha brainwaves in the mental imagery experiment in sport: the "Your Home Venue" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The study's main aim was to examine the cortical correlations of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with the...
-
Power of the SMR brainwaves in the mental imagery experiment in sport: the "Fitness Activity" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The main aim of the study was to examine the cortical correlates of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with...
-
Power of the SMR brainwaves in the mental imagery experiment in sport: the "Slow Start" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The main aim of the study was to examine the cortical correlates of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with...
-
Power of the high alpha brainwaves in the mental imagery experiment in sport: the "Training Session" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The study's main aim was to examine the cortical correlations of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with the...
-
Power of the SMR brainwaves in the mental imagery experiment in sport: the "Successful Competition" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The study's main aim was to examine the cortical correlations of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with the...
-
Power of the SMR brainwaves in the mental imagery experiment in sport: the "Training Session" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The study's main aim was to examine the cortical correlations of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with the...
-
Power of the low alpha brainwaves in the mental imagery experiment in sport: the "Training Session" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The study's main aim was to examine the cortical correlations of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with the...
-
Power of the high alpha brainwaves in the mental imagery experiment in sport: the "Slow Start" scenario.
Open Research DataThe data were collected to perform research on the neural oscillation during mental imagery in sport. The main aim of the study was to examine the cortical correlates of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with...