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Search results for: BROWNIAN MOTION
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Diagnostics of induction motor bearings - possibility of measurements
PublicationIn induction motors damage in the elements of electromagnetic system, for example in the wiring of stator, rotor or in the magnetic circuit can appear as well as damage of mechanical parts (bearings, rotor, shaft). Bearing diagnostics is so important in supervision of motor condition, because extensive research shows that the bearings arethe elements most susceptible to damage. This paper presents the research which the author...
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Electric motor drive with inverter output filter
PublicationPrzedstawiono zagadnienie sterowania i estymacji w układzie napędowym z silnikiem indukcyjnym i filtrem sinusoidalnym.Filtr użyty jest do wygładzenia prądu i napięcia silnika. Filtr wprowadza spadek napięcia i przesunięcie fazowe prądów i napięć uniemożliwiające stosowane bezczujnikowych metod sterowania wektorowego. Rozwiązaniem jest uwzględnienie filtru w sterowaniu i estymacji. Artykuł pokazuje takie rozwiązanie dla metody sterowania...
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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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Recognition of Emotions in Speech Using Convolutional Neural Networks on Different Datasets
PublicationArtificial Neural Network (ANN) models, specifically Convolutional Neural Networks (CNN), were applied to extract emotions based on spectrograms and mel-spectrograms. This study uses spectrograms and mel-spectrograms to investigate which feature extraction method better represents emotions and how big the differences in efficiency are in this context. The conducted studies demonstrated that mel-spectrograms are a better-suited...
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Testing motional accuracy of a manufacturing machine - a task imposed on modern maintenance
PublicationArtykuł dotyczy zagadnień utrzymania ruchu maszyn w powiązaniu z problemami parametryzacji zautomatyzowanych napędów. Przedstawiono krótki przegląd i kierunki rozwoju wspomagania komputerowego w ramach zakładowych systemów utrzymania ruchu. Zwrócono uwagę na pomijanie w popularnie publikowanych graficznych modelach systemów informatycznych CIM, ich podsystemów dedykowanych dla wspomagania utrzymania ruchu maszyn, podczas gdy takie...
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EFFECT OF ANTIOXIDANTS ON THE STABILITY OF PITCH- BASED POLYMER TO THERMO-OXIDATIVE ACTION
PublicationThe influence of stabilizers – hydrogen donors – on the processes of thermooxidative destruction of pitch-based polymer has been investigated. It is shown that Irganox has not stabilizing effect on pitch-based polymer and melamine slightly retards the destructive process. A mixture of melamine and Irganox exhibits synergetic stabilizing effect and at the optimum ratio it can be used to prevent unwanted thermooxidative processes...
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State Interventionism in Tax System - Example of Action in a COVID-19 Crisis
PublicationThe following article presents and classifies changes in tax systems of selected countries as well as counts them as the response to the emergence of the crisis caused by the COVID-19 pandemic. Such actions were undertaken the context of state interventionism in the tax system. In order to achieve the objective of presenting the state interventionism in the context of tax rates, an analysis of the literature on the phenomenon described,...
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Expansion of the self of activists and nonactivists involved in mass gatherings for collective action
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Theoretical interpretations of photoelectron spectra of platinum atom, its cation and anion
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Molecular action of isoflavone genistein in the human epithelial cell line HaCaT
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The molecular mechanism of genistein action in lysosomal storage diseases: A transcriptomic approach
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Agomelatine's antiglycoxidative action—In vitro and in silico research and systematic literature review
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Sustainable carbon microtube derived from cotton waste for environmental applications
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Two-step mechanism of J-domain action in driving Hsp70 function
PublicationJ-domain proteins (JDPs), obligatory Hsp70 cochaperones, play critical roles in protein homeostasis. They promote key allosteric transitions that stabilize Hsp70 interaction with substrate polypeptides upon hydrolysis of its bound ATP. Although a recent crystal structure revealed the physical mode of interaction between a J-domain and an Hsp70, the structural and dynamic consequences of J-domain action once bound and how Hsp70s...
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Action Research: Cooperation of Practitioners and Researchers for Knowledge Development in Public Organisations
PublicationAction Research (AR) is not only a research method or a research strategy for solving a research problem, but also an effective tool for developing knowledge and implementing changes in the organization. The aim of AR is to bring about a change within the studied area and get participants to initiate changes, in which the researcher and the recipient collaborate in investigating the problem and developing a relevant solution. AR...
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Thermal self-action effects of acoustic beam in a vibrationally relaxing gas
PublicationThermal self-action of acoustic beam in a molecular gas with excited internal degrees of molecules’ freedom, is studied. This kind of thermal self-action differs from that in a Newtonian fluid. Heating or cooling of a medium takes place due to transfer of internal vibrational energy. Equilibrium and non-equilibrium gases, which may be acoustically active, are considered. A beam in an acoustically active gas is self-focusing unlike...
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xEmotion – obliczeniowy model emocji dedykowany dla inteligentnych systemów decyzyjnych
PublicationArtykuł prezentuje cybernetyczne podejście do zagadnienia modelowania ludzkich emocji, oparte na psychologicznych teoriach (ocennej i somatycznej). Opracowany model przeznaczony jest do integracji z Inteligentnym Systemem Decyzyjnym – IDS. Może być on używany jako silnik aplikacji lub jako system sterowania niezależnego urządzenia, np. robota autonomicznego.
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Thermal Self-Action of Acoustic Beams Containing Several Shock Fronts
PublicationThermal self-action of an acoustic beam with one discontinuity or several shock fronts is studied in a Newtonian fluid. The stationary self-action of a single sawtooth wave with discontinuity (or some integer number of these waves), symmetric or asymmetric, is considered in the cases of self-focusing and self- defocusing media. The results are compared with the non-stationary thermal self-action of the periodic sound. Thermal self-action...
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Multi-Option Model of Railway Traffic Organization Including the Energy Recuperation
PublicationThe article presents the issue of organization of railway traffic within the station, taking into account energy recuperation. We identified a number of factors which affect the energy efficiency of recuperation, including the issue of transfer of energy technology between a few vehicles. We presented some aspects of the decision problem of graphic train timetable construction with regard to recuperation. As an indicator of quality...
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Improvement of electrochemical action of zinc-rich paints by addition of nanoparticulate zinc
PublicationThe influence of nanosized particles on electrochemical action of standard zinc-rich paints by means of SEM as well as potential and impedance measurements has been investigated. The motivation for doing this was to obtain additional electrical connection between the spherical microparticles themselves and zinc particles and steel substrate. Overall zinc content was at the level of 92% by weight. Samples with different concentration...
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Machine Learning for Sensorless Temperature Estimation of a BLDC Motor
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Hybrid piezoelectric motor based on electroactive lubrication principle
PublicationA novel conception of hybrid piezoelectric motor is presented in this paper. Proposed conception required synchronised work of quasi-static and resonant piezoelectric actuators that results in a rotary movement. The motor's working principle is explained and the main characteristics are described. Studied topology is compared to the existing piezoelectric motors with regards to its field of applications. The assembling process...
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An advanced low-cost sensorless induction motor drive
PublicationW artykule przedstawiono układ sterowania silnikiem asynchronicznym klatkowym pracujący bez pomiaru prędkości obrotowej. Układ zrealizowano na tanim procesorze stałoprzecinkowym. aspekty praktyczne realizacji układu rozpatrzono na podstawie uzyskanych wyników z symulacji i eksperymentu.
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Parametrical 3D model of an asynchronous motor - AutoCAD application.
PublicationA computer program for automatic drawing of 3D models of squirrel-cage induction motors is presented in this paper. The created model of a machine is of parametrical nature, which means that the user defines geometry of particular elements (shaft, stator core, bearing, windings etc.) on the basis dimensions and some other parameters e.g. type of bearing, kind of winding, number of slots. This program is useful for 3D modelling...
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Sensorless multiscalar controls of induction motor at low speed
PublicationW artykule przedstawiono zastosowanie obserwatora prędkości w dwóch różnych układach sterowania multiskalarnego silnikiem klatkowym. Pierwszy układ bazuje na prądzie stojana i strumieniu wirnika, natomiast drugi nowy układ wykorzystuje zmienne prąd stojana i strumień stojana. Zamieszczono wyniki badań symulacyjnych i eksperymentalych w układzie ze sterowaniem na procesorze SHARC.
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Neural networks in the diagnostics of induction motor rotor cages.
PublicationW środowisku Lab VIEW została stworzona aplikacja służąca do pomiaru, prezentacji i zapisu przebiegów widma prądu stojana z uwzględnieniem potrzeb pomiarowych występujących podczas badania wirników silników indukcyjnych przy użyciu sieci neuronowych. Utworzona na bazie zbioru uczącego sieć Kohonena z powodzeniem rozwiązała stawiany przed nią problem klasyfikacji widm prądu stojana, a co za tym idzie również diagnozy stanu...
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Determination of the theoretical and actual working volume of a hydraulic motor
PublicationA new methodology of determination of the theoretical and actual working volume of a hydraulic motor based on the characteristics of the delivered flow rate into hydraulic motor vs. the rotational speed at a constant pressure drop in the working chambers is described in this paper. A new method of describing the delivered flow rate into a motor per one shaft revolution as a nonlinear function of the pressure drop in the motor working...
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Comparative analysis of switched reluctance motor control algorithms
PublicationПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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The multiscalar control of induction motor with the sliding mode controllers
PublicationThe control structure of induction motor is proposed in this paper. The structure of multiscalar control with conventional PI - controllers is well known in literature. The sliding mode multiscalar control (SMMC) conception is presented in this paper. The induction motor is fed by voltage source inverter. Comparison between two multiscalar control method is showed.
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Model and laboratory simulation of a induction motor for diagnostic purposes
PublicationStatistics say that bearings are this part of induction motors which is most susceptible to damage. The equipment employed for bearing diagnostics usually makes use of vibrations as the criterion for technical condition of the bearings. A faulty bearing results in additional motor vibrations. They are reflected in the harmonic content of stator currents. In certain operating conditions the current signal is the sole source of information...
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Predictive current controller for sensorless induction motor drive
PublicationPrzedstawiono układ bezczujnikowego sterowania dla napedu z silnikiem klatkowym przy zastosowaniu predykcyjnego regulatora pradu. Zastosowany obserwator adaptacyjny wykazuje dużą odporność na zmiany parametrów silnika. W obserwatorze obliczane są wartości sił elektromotorycznych wykorzystywane w procesie regulacji predykcyjnej pradu silnika. Pokazano wyniki badań symulacyjnych i eksperymentalnych.
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Design and modeling of switched reluctance motor for scooter application
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Sensorless induction motor drive for electric vehicle application
PublicationW artykule przedstawiono układ napędowy pojazdu elektrycznego wykorzystujący niezawodny i tani silnik prądu przemiennego. Zastosowany trójfazowy silnik asynchroniczny klatkowy wymaga zasilaniaz falownika napięcia przekształcającego napięcie stałe z akumulatorów na napięcie przemienne. Wykonany tranzystorowy przekształtnik sterowany jest mikroprocesorowo. Zastosowany procesor realizuje algorytm sterowania polowo zorientowanego,...
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The influence of pressure drop on the working volume of a hydraulic motor
PublicationReliability and maintenance analysis of hydraulic positive machines basicly focused on the processes of their wear and failure. But in order to correctly assess the mechanical and volumetric efficiency of a hydraulic motor, both at the stage of development research or at the stage of control tests during its exploitation, the working volume of this motor must be correctly determined. Therefore this paper proposes a new method of...
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Knowledge representation of motor activity of patients with Parkinson’s disease
PublicationAn approach to the knowledge representation extraction from biomedical signals analysis concerning motor activity of Parkinson disease patients is proposed in this paper. This is done utilizing accelerometers attached to their body as well as exploiting video image of their hand movements. Experiments are carried out employing artificial neural networks and support vector machine to the recognition of characteristic motor activity...
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Investigations on the the dynamics of motor vehicle driving in nighttime conditions
PublicationThe article describes investigations on vehicle driving in nighttime conditions
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Chosen Analysis Results Of The Prototype Multicell Piezoelectric Motor
PublicationThis paper presents the design, modeling and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one - referred to as a “single cell” (single actuator). Combined three resonant actuators generate three traveling waves...
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Motor bearing diagnostics performed by means of laser vibrometer
PublicationDamage of bearings is the most common cause of failures in squirrel-cage induction motors. That is why the issues connected with diagnostics of bearings are so important. The equipment employed for bearing diagnostics usually makes use of vibrations as the criterion for technical condition of the bearings. This paper presents exemplary results of the research conducted on bearings with artificially introduced damage. A scanning...
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Simple observer for induction motor speed sensorless control
PublicationPrzedstawiono układ sterowania polowo zorientowanego silnikiem asynchronicznym klatkowym pozwalający na pracę w szerokim zakresie prędkości obrotowych bez użycia czujnika prędkości. Zaproponowano estymator zmiennych o prostej strukturze charakteryzujący się znaczna odpornością na zmiany parametrów silnika. Zależności obserwatora oparte są na równaniach obwodu napięciowego silnika. Pokazano wyniki badań eksperymentalnych.
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Lessons learned during SRAD hybrid motor development
PublicationStudent Researched and Developed (SRAD) hybrid rocket motor H-15 with total impulse of 15 $kNs$ was built. First version of the engine has average thrust of 3 $kN$, the second, improved one is prepared with an aim to have average thrust of 5 $kN$. Engine development was started from scratch and went through phases of: definition of design assumptions and constraints, numerical modelling to predict engine performance, CAD and CAM...
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Comparative analysis of switched reluctance motor control algorithms
PublicationПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Action of an Antiserum to a-Tocoquinone on Photosystem II-Particle Preparations of N icotiana tabacum
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Chain Action - How Do Countries Add Value Through Digital Government?
PublicationThis study examineshow countries develop and benefit from Digital Government(DG).The literature proposes various conceptualizations of the value-adding logic of DG, but the benchmarking practice is not respondingto such proposals.For instance, the United Nations’E-Government Surveycombines the readiness and uptake indicatorsand failsto cover any impactindicators;thus,its diagnostic valueis limited. To overcome...
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THE IMPACT OF EMOTIONS ON CHANGES IN THE CORRELATION COEFFICIENT BETWEEN DIGITAL IMAGES OF THE HUMAN FACE
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Studies on the complex formation between lactams and thiolactams of sparteine with copper(II) cation
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Evaluation of Analytes Characterized with Potential Protective Action after Rat Exposure to Lead
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Synthesis, crystal structure and electrical properties of A-site cation ordered BaErMn2O5 and BaErMn2O6
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Isothiocyanates as effective agents against enterohemorrhagic Escherichia coli: insight to the mode of action
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Various modes of action of dietary phytochemicals, sulforaphane and phenethyl isothiocyanate, on pathogenic bacteria
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Study of pozzolanic action of ground waste expanded perlite by means of thermal methods
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