Search results for: canonical circuit
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The measurement of input power of power supply in network disturbed by low frequency distortions
PublicationIn the paper authors present results of observation of input power changes versus harmonics amplitude in supply voltage of low-power power supply device. In the study, the electrical measurements supported with thermal imaging were used. The input circuit elements of studied device responsible for input power increase are pointed
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Photovoltaic phenomena in devices with perfluorozincphthalocyanine layer
PublicationThe course of photovoltaic phenomenon in organic photovoltaic cells utilizing thin layers of perfluorozincphthalocyanine was studied in few single and planar bilayer configurations. Mechanisms of photogeneration and recombination of free charge carriers were determined and active interfaces were localized. In case of single layer cells these interfaces were located at the front electrode/F16ZnPc junctions, whereas photogeneration...
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Rearrangements of the nitrifiers population in an activated sludge system under decreasing solids retention times
PublicationDue to the key role of nitrite in novel nitrogen removal systems, nitrite oxidizing bacteria (NOB) have been receiving increasing attention. In this study, the coexistence and interactions of nitrifying bacteria were explored at decreasing solids retention times (SRTs). Four 5-week washout experiments were carried out in laboratory-scale (V=10 L) sequencing batch reactors (SBRs) with mixed liquor from two full-scale activated sludge...
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Inverse and forward surrogate models for expedited design optimization of unequal-power-split patch couplers
PublicationIn the paper, a procedure for precise and expedited design optimization of unequal power split patchcouplers is proposed. Our methodology aims at identifying the coupler dimensions that correspond to thecircuit operating at the requested frequency and featuring a required power split. At the same time, thedesign process is supposed to be computationally efficient. The proposed methodology involves two typesof auxiliary models (surrogates):...
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Induction Generator with Direct Control and a Limited Number of Measurements on the Side of the Converter Connected to the Power Grid
PublicationThe article presents an induction generator connected to the power grid using the AC/DC/AC converter and LCL coupling filter. Three-level inverters were used in the converter, both from the generator side and the power grid side. The algorithm realizing Pulse Width Modulation (PWM) in inverters has been simplified to the maximum. Control of the induction generator was based on the Direct Field-Oriented Control (DFOC) method. At...
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Rapid dimension scaling of compact microwave couplers with power split correction
PublicationIn this paper, a technique for rapid re-design ofcompact microwave couplers with respect to operating frequency is discussed. Our methodology involves an inverse surrogate model setup using several reference designs optimized (at the level of equivalent circuit representation of the coupler) for a set of operating frequencies within a range of interest. The surrogate establishes the relationship between the operating frequency...
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Accelerated simulation-driven design optimisation of compact couplers by means of two-level space mapping
PublicationIn this study, the authors discuss a robust and efficient technique for rapid design of compact couplers. The approach exploits two-level space mapping (SM) correction of an equivalent circuit model of the coupler structure under design. The first SM layer (local correction) is utilised to ensure good matching between the equivalent circuit and the electromagnetic model at the component level. Subsequent global correction allows...
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Time-current tripping curves of arc fault detection devices
PublicationTripping curves of arc fault detection devices, in accordance with PN-EN 62606 “General requirements for arc fault detection devices” have been presented in the paper. Consequently the most fundamental differences in arc fault detection devices tripping compared to circuit-breakers and residual current devices have been indicated.
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Electrochemical cell impedance spectra at Eoc+100mV
Open Research DataThe dataset presents impedance spectrum of electrochemical cell filled with 3% NaCl solution presented in the figure below. This cell was used measured using Atlas-Sollich 0531 impedance analyser with built-in potentiostat. When changing the DC polarisation of the cell the non-linear phenomena could be observed. The impedance spectrum frequency range...
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Electrochemical cell impedance spectra at Eoc+200mV
Open Research DataThe dataset presents impedance spectrum of electrochemical cell filled with 3% NaCl solution presented in the figure below. This cell was used measured using Atlas-Sollich 0531 impedance analyser with built-in potentiostat. When changing the DC polarisation of the cell the non-linear phenomena could be observed. The impedance spectrum frequency range...
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Electrochemical cell impedance spectra at Eoc-100mV
Open Research DataThe dataset presents impedance spectrum of electrochemical cell filled with 3% NaCl solution presented in the figure below. This cell was used measured using Atlas-Sollich 0531 impedance analyser with built-in potentiostat. When changing the DC polarisation of the cell the non-linear phenomena could be observed. The impedance spectrum frequency range...
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Electrochemical cell impedance spectra at Eoc
Open Research DataThe dataset presents impedance spectrum of electrochemical cell filled with 3% NaCl solution presented in the figure below. This cell was used measured using Atlas-Sollich 0531 impedance analyser with built-in potentiostat. When changing the DC polarisation of the cell the non-linear phenomena could be observed. The impedance spectrum frequency range...
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Electrochemical cell impedance spectra at Eoc-200mV
Open Research DataThe dataset presents impedance spectrum of electrochemical cell filled with 3% NaCl solution presented in the figure below. This cell was used measured using Atlas-Sollich 0531 impedance analyser with built-in potentiostat. When changing the DC polarisation of the cell the non-linear phenomena could be observed. The impedance spectrum frequency range...
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Natural convective heat transfer from isothermalconic
PublicationTheoretical considerations on convective heat transfer from isothermal upward conicalsurfaces have been presented. The physical model of this phenomenon consists of an isothermalcone of inclination angle (φ) between the cone generating line (X) and the radius (R) of the cone base. The angle is a parameter of conical surface which varied from (φ = 0−circular horizontal plate) to (φ = π/2—vertical cylinder) . Onthe basis of Navier–Stokes...
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Estimation of a single balun parameters on the base of back-to-back measurements
PublicationA method of estimation of a single balun S parameters based on the measured parameters of back-to-back configuration is presented in the paper. Proposed approach is to measure two back-to-back circuits: i) direct connection of baluns and ii) connection with additional transmission line segment between the baluns. Coupling effects in both circuits are calculated from full-wave simulations. Next they are applied to estimate the parameters...
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Wideband crossover structure with double ring resonators
PublicationThe structure of a four-port microstrip crossover is presented. The device is composed of two ring resonators, one circular and one built from meander lines, connected by four straight lines. The equivalent circuit model of the crossover is derived. The structure is designed on thin and flexible substrate to allow it to bend. The possibility of applying the device on curved surfaces is tested experimentally.
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Design considerations for compact microstrip resonant cells dedicated to efficient branch-line miniaturization
PublicationA conventional compact microstrip resonant cell (CMRC)has been thoroughly investigated to enhance its slow-wave properties and subsequently ensure an efficient miniaturization of a microstrip circuit. The geometry of a classic CMRC has been improved in terms of slowwave effect in two progressive steps: (i) a single-element topology has been replaced with a double-element one and (ii) a high-impedance section has been refined by...
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Design of a compact planar transmission line for miniaturized rat-race coupler with harmonics suppression
PublicationThis paper presents an elegant yet straightforward design procedure for a compact rat-race coupler (RRC) with an extended harmonic suppression. The coupler’s conventional λ/4 transmission lines (TLs) are replaced by a specialized TL that offers significant size reduction and harmonic elimination capabilities in the proposed approach. The design procedure is verified through the theoretical, circuit, and electromagnetic (EM) analyses,...
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An idea of an approach to self-testing of mixed signal systems based on a quadratic function stimulation
PublicationA new approach to self-testing of the analog parts of mixed-signal electronic systems controlled by microcontrollers equipped with an ADC and a DAC is presented. It is based on a BIST and a new fault diagnosis method. A novelty is the use of the DAC as a component of the BIST, allowing to generate a stimulating signal with a quadratic function shape. It contributes to a better extraction of information about the state of the circuit...
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A cryptic ribosome binding site, false signals in reporter systems and avoidance of protein translation chaos
PublicationThe expression of reporter gene may be induced by activation of cryptic signalling sequences, as we found while constructing the mutS-lacZ fusion gene. We cloned the Escherichia coli lacZ gene encoding beta-galactosidase into a plasmid vector carrying the Thermus thermophilus mutS gene. The clones expected to produce beta-galactosidase as the C-terminal fusion were selected for the complementation of beta-galactosidase activity...
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Distinguishing of cocrystals from simple eutectic mixtures: phenolic acids as potential pharmaceutical coformers
PublicationThe multiparameter model comprising 1D and 2D QSPR/QSAR descriptors was proposed and validated for phenolic acid binary systems. This approach is based on the optimization of regression coefficients for maximization of the percentage of true positives in the pool of systems comprising either simple binary eutectics or cocrystals. The training set consisted of 58 eutectics and 168 cocrystals. The solid dispersions collection used...
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Influence of addition of carbon nanotubes on rheological properties of selected liquid lubricants - a computer simulation study
PublicationThis work is motivated by the improvement of anti-friction properties of lubricants by addition of CNTs proved experimentally in literature. In particular, a methodology is developed to compute the shear viscosity of liquid lubricants (Propylene Glycol) based on Molecular Dynamics simulation. Non-Equilibrium molecular dynamics (NEMD) approach is used with a reactive force field ReaxFF implemented in LAMMPS. The simulations are...
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Atmospheric degradation mechanism of anthracene initiated by OH•: A DFT prediction
PublicationDensity functional theory (DFT) calculations at the M06-2X/def2-TZVP level have been employed to investigate the atmospheric oxidation mechanism of anthracene (ANT) initiated by HO•. Direct hydrogen atom abstraction from the ANT using HO• takes place hardly at ambient conditions while the addition of HO• to the C1, C2, and C4 sites are thermodynamically and kinetically more advantageous. The addition reactions are controlled by...
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Arithmetic Loophole in Bell's Theorem: Overlooked Threat to Entangled-State Quantum Cryptography
PublicationBell’s theorem is supposed to exclude all local hidden-variable models of quantum correlations. However,an explicit counterexample shows that a new class of local realistic models, based on generalized arith-metic and calculus, can exactly reconstruct rotationally symmetric quantum probabilities typical oftwo-electron singlet states. Observable probabilities are consistent with the usual arithmetic employedby macroscopic observers...
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Quantum entanglement
PublicationAll our former experience with application of quantum theory seems to say that what is predicted by quantum formalism must occur in the laboratory. But the essence of quantum formalism-entanglement, recognized by Einstein, Podolsky, Rosen, and Schrödinger-waited over 70 years to enter laboratories as a new resource as real as energy. This holistic property of compound quantum systems, which involves nonclassical correlations between...
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Szybkie uziemniki do ograniczania skutków zwarć łukowych w okrętowych rozdzielnicach SN
PublicationW artykule scharakteryzowano moc i napięcie łuku, jak również przedstawiono model termodynamiczny służący do obliczania ciśnienia i temperatury gazów w otoczeniu łuku zwarciowego. Przedstawiono przykładowy układ elektrowni okrętowej i zasilania najważniejszych odbiorników na statku do przewozu gazu ziemnego w stanie ciekłym. Na podstawie parametrów prądnic i silników odbiorników zasilanych z rozdzielnicy głównej obliczono prądy...
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Testing HIADAC high impedance analyzer in Trento University laboratory on protective foil using 2-wire probe 24h exposition
Open Research DataThe dataset presents impedance spectrum of anticorrosion foil (coating) protecting aluminium frame . This object was used to test high-impedance analyzer for diagnostic of anticorossion coatings (HIADAC) realized in the frame of Eureka project E!3174. The impedance spectrum frequency range (0.1 Hz – 100 kHz) was selected in order to test the whole...
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Testing HIADAC high impedance analyzer in Trento University laboratory on protective foil using 2-wire probe 48h exposition
Open Research DataThe dataset presents impedance spectrum of anticorrosion foil (coating) protecting aluminium frame . This object was used to test high-impedance analyzer for diagnostic of anticorossion coatings (HIADAC) realized in the frame of Eureka project E!3174. The impedance spectrum frequency range (0.1 Hz – 100 kHz) was selected in order to test the whole...
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Zaawansowane Metody Pomiarowe i Diagnostyczne 2022/2023
e-Learning Courses{mlang en} 1. Introduction/Guide for the use of the International System of Units2. Rules and style conventions for expressing values of quantities.3. The role of measurement uncertainty in conformity assessment. 4. Probabilistic model for measurement processes, estimation theory5. Analog-digital conversion methods6. Selected structures of classical analog-digital converters7. New techniques of analog-digital conversion: sigma-delta...
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Zaawansowane Metody Pomiarowe i Diagnostyczne 2023/2024
e-Learning Courses{mlang en} 1. Introduction/Guide for the use of the International System of Units2. Rules and style conventions for expressing values of quantities.3. The role of measurement uncertainty in conformity assessment. 4. Probabilistic model for measurement processes, estimation theory5. Analog-digital conversion methods6. Selected structures of classical analog-digital converters7. New techniques of analog-digital conversion: sigma-delta...
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A Novel Coupling Matrix Synthesis Technique for Generalized Chebyshev Filters With Resonant Source–Load Connection
PublicationThis paper reports a novel synthesis method for microwave bandpass filters with resonant source–load connection. In effect, a network realizing N+1 transmission zeros (where N is the number of reflection zeros) is obtained. The method is based on a prototype transversal coupling matrix (N+2, N+2) with source and load connected by a resonant circuit formed by a capacitor in parallel with a frequency-invariant susceptance. To complement...
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Hybrid‐mode single‐slope ADC with improved linearity and reduced conversion time for CMOS image sensors
PublicationIn the paper, a single‐slope analog‐to‐digital converter (ADC) for integrated CMOS image sensor applications with an improved technique of conversion has been proposed. The proposed hybrid‐mode ADC automatically uses one of the following conversion techniques: time based (i.e. PWM) or voltage based (i.e. single‐slope). During the ADC operation, the clock frequency and reference voltage are modified in order to reduce the conversion...
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Programmable feedforward linearized CMOS OTA for fully differential continuous-time filter design
PublicationW artykule przedstawiono metodę linearyzacji wzmacniacza transkonduktancyjnego (OTA) CMOS z zastosowaniem sprzężenia w przód. Wzmacniacz zbudowany jest z użyciem prostych par różnicowych, wzmacniacza w pętli sprzężenia zwrotnego do samoregulacji transkonduktancji wzmacniaczy oraz liniowej rezystancji odniesienia (R). W wyniku uzyskano znaczną linaryzację charakterystyk przejściowych wzmacniacza OTA. Symulacje komputerowe SPICE...
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Multiple output differential OTA with linearizing bulk-driven active-error feedback loop for continuous-time filter applications
PublicationA CMOS circuit realization of a highly linear multiple-output differential operational transconductance amplifier (OTA) has been proposed. The presented approach exploits a differential pair as an input stage with both the gate and the bulk terminals as signal ports. For the proposed OTA, improved linearity is obtained by means of the active-error feedback loop operating at the bulk terminals of the input stage. SPICE simulations...
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A general approach to continuous time Gm-C filters.
PublicationW pracy zaproponowano ogólną strukturę filtrów Gm-C z odpowiednim opisem macierzowym. W odniesieniu do tej struktury podano formuły analizy wrażliwościowej dla dowolnego filtru Gm-C czasu ciągłego. Analiza oparta na opisie macierzowym była wykorzystana również do porównania właściwości filtrów Gm-Ctrybu napięciowego i prądowego. Zdefiniowano dwie kanoniczne transformacje dla klasy filtrów zmiennych stanu.
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Novel doubly perforated broadband microstrip branch-line couplers
PublicationTwo broadband compact doubly perforated hybrid couplers have been designed, manufactured, and measured. To improve frequency characteristics and to reduce circuit dimensions, two kinds of perforations have been introduced: the defected ground structures in the ground plane metallization and photonic bandgap cells in the strip metallization. Measurement results show essential miniaturization (~39% and ~36%) and enhancement of the...
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Programmable dynamically changing RC model for evaluation of Dynamic EIS methods and instrumentation
PublicationThe paper concerns the RC equivalent circuit of electrochemical cell with the impedance changed during the experiment. The model was constructed using the digital potentiometers controlled by the microcontroller. This solution allows to control the model impedance by the software means. By creating adequate changes of the impedance spectrum as a time function, the different impedance measurement method can be tested to find out...
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Automated detection of pronunciation errors in non-native English speech employing deep learning
PublicationDespite significant advances in recent years, the existing Computer-Assisted Pronunciation Training (CAPT) methods detect pronunciation errors with a relatively low accuracy (precision of 60% at 40%-80% recall). This Ph.D. work proposes novel deep learning methods for detecting pronunciation errors in non-native (L2) English speech, outperforming the state-of-the-art method in AUC metric (Area under the Curve) by 41%, i.e., from...
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PROJEKT ZESPOŁOWY [DK][2023/24]
e-Learning CoursesCCCLECTURE and Classes: Power supply systems for industrial facilities. Devices and main circuits of MV power stations. Short-circuit calculation. Power protection automation. Security classification according to American ANSI standards used in the EU. Microprocessor protection relays. Drive systems for medium power and medium voltage pumps. Roving inverters. PROJECT: Design of a MV switching station for a medium-power pumping...
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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...
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Fast geometry scaling of miniaturized microwave couplers with power split correction
PublicationRedesigning a microwave circuit for various operating conditions is a practically important yet challenging problem. The purpose of this article is development and presentation of a technique for fast geometry scaling of miniaturized microwave couplers with respect to operating frequency. Our approach exploits an inverse surrogate model constructed using several reference designs that are optimized for a set of operating frequencies...
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Role of surface recombination in perovskite solar cells at the interface of HTL/CH3NH3PbI3
PublicationIn order to achieve the highest performance of organometal trihalide perovskite solar cells, it is required to recognize the dominant mechanisms which play a key role in a perovskite material. In the following studies, we have focused on the interfacial recombination between the hole transporting layer (HTL) and the perovskite CH3NH3PbI3 in solar cell devices with p–i–n architecture. It has been shown that Cu:NiOx : used as HTL...
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New ceramic materials derived from pyrolyzed poly(1,2-dimethylsilazane) and starch as a potential anode for Li-ion batteries
PublicationNewmaterialswere obtained by pyrolysis of starch (S) and poly(1,2-dimethylsilazane) (PSN) (weight ratio: PSN/S 30/70) at temperature a) 500 °C, b) 700 °C and c) 900 °C. Ceramic materials were characterized by infrared spectroscopy, TGA, Raman spectroscopy and SEM. New Si\O and shifted Si\C stretching vibration modes emerged confirming direct interaction between silicon originating fromsilazane and oxygen coming fromstarch. The...
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Direct Constraint Control for EM-Based Miniaturization of Microwave Passives
PublicationHandling constraints imposed on physical dimensions of microwave circuits has become an important design consideration over the recent years. It is primarily fostered by the needs of emerging application areas such as 5G mobile communications, internet of things, or wearable/implantable devices. The size of conventional passive components is determined by the guided wavelength, and its reduction requires topological modifications,...
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Design centering of compact microwave components using response features and trust regions
PublicationFabrication tolerances, as well as uncertainties of other kinds, e.g., concerning material parameters or operating conditions, are detrimental to the performance of microwave circuits. Mitigating their impact requires accounting for possible parameter deviations already at the design stage. This involves optimization of appropriately defined statistical figures of merit such as yield. Alt-hough important, robust (or tolerance-aware)...
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Optimization-Based Robustness Enhancement of Compact Microwave Component Designs with Response Feature Regression Surrogates
PublicationThe ability to evaluate the effects of fabrication tolerances and other types of uncertainties is a critical part of microwave design process. Improving the immunity of the device to parameter deviations is equally important, especially when the performance specifications are stringent and can barely be met even assuming a perfect manufacturing process. In the case of modern miniaturized microwave components of complex topologies,...
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Noise in electrical double-layer capacitors (EDLCs)
PublicationWe present methods and problems of noise measurements in electrical double-layer capacitors (EDLC). Detailed noise equivalent electronic circuit is considered, and two possible ways of observations of random processes generated in the EDLCs structures are studied. We conclude that noise is a useful tool for characterization of the EDLC structures and their state-of-health, as in other materials and electronic devices. Eventual,...
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Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...
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Krzysztof Nyka dr hab. inż.
PeopleKrzysztof Nyka, received MSc (1986) PhD (2002) and DSc (2020) degrees in telecommunication and electrical engineering from the Faculty of Electronics, Telecommunications and Informatics (ETI) of Gdańsk University of Technology (GUT), Poland. He is currently an Associate Professor at the Department of Microwaves and Antenna Engineering, Faculty of ETI, GUT. Before his academic career, he worked for the electronic industry (1984-1986). Research...
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Application of Open-Hardware-Based Solutions for Rapid Transition From Stationary to the Remote Teaching Model During Pandemic
PublicationWhile research indicates usefulness of remote laboratories in teaching of digital hardware systems, their main application is to complement stationary classes. This work presents a low-cost, scalable architecture that supports rapid transformation of teaching to a model based solely on remote access mechanisms. Background: Adaptation of online laboratory solutions from the literature to en-masse teaching of digital circuits is...