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Wyniki wyszukiwania dla: ADAPTIVE PERTURBATIONS
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ADAPTIVE BEHAVIOR
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Modern Arrangement for Reduction of Voltage Perturbations
PublikacjaThe contents of this chapter encompass general problems and the most important issues of power-supply-quality improvement in AC systems. In the context of the above, consideration is given to evaluation of bilateral interactions of receivers with an electrical power-distribution system and methods of their reduction. Also are discussed the basis of operation of the most important compensation-filtration devices and their applications...
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Offsetting, relations, and blending with perturbation functions
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Hysteresis curves for some periodic and aperiodic perturbations in gases
PublikacjaEvolution of sound in a medium whose properties irreversibly vary in the course of wave propagation, is studied. For example, a gas that is a particular case of a Newtonian fluid is considered. Hysteresis curves, pictorial representations of irreversible attenuation of the sound energy, in the plane of thermodynamic states are plotted. The irreversible losses in internal energy are proportional to the total attenuation and depend...
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Identification of Continuous Systems - Practical Issues of Insensitivity to Perturbations
PublikacjaIn this paper the issue of continuous systems estimation, insensitive to certain perturbations, is discussed. Such an approach has rational advantages, especially when robust schemes are used to assist a target system responsible for industrial diagnostics. This requires that estimated model parameters are generated on-line, and their values are reliable and to a great extent accurate. Practical hints are suggested to challenge...
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Identification of continuous systems - Practical issues of insensitivity to perturbations
PublikacjaIn this paper the issue of continuous systems estimation, insensitive to certain perturbations, is discussed. Such an approach has rational advantages, especially when robust schemes are used to assist a target system responsible for industrial diagnostics. This requires that estimated model parameters are generated on-line, and their values are reliable and to a great extent accurate. Practical hints are suggested to challenge...
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Periodic Solutions of Generalized Lagrangian Systems with Small Perturbations
PublikacjaIn this paper we study the generalized Lagrangian system with a small perturbation. We assume the main term in the system to have a maximum, but do not suppose any condition for perturbation term. Then we prove the existence of a periodic solution via Ekeland’s principle. Moreover, we prove a convergence theorem for periodic solutions of perturbed systems.
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Periodic solutions of Lagrangian systems under small perturbations
PublikacjaIn this paper we prove the existence of mountain pass periodic solutions of a certain class of generalized Lagrangian systems under small perturbations. We show that the found periodic solutions converge to a periodic solution of the unperturbed system if the perturbation tends to 0. The proof requires to work in a rather unusual (mixed) Orlicz–Sobolev space setting, which bears several challenges.
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Hysteresis curves for some periodic and aperiodic perturbations in magnetosonic flow
PublikacjaA thermodynamic relation between perturbations of pressure and mass density in the magnetohydrodynamic flow is theoretically studied. Planar magnetohydrodynamic perturbations with the wave vector, which forms a constant angle with the equilibrium magnetic field, are under study. The theory considers thermal conduction of a plasma and the deviation from adiabaticity of a flow due to some kind of heating–cooling function. It also...
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Otopy Classification of Gradient Compact Perturbations of Identity in Hilbert Space
PublikacjaWe prove that the inclusion of the space of gradient local maps into the space of all local maps from Hilbert space to itself induces a bijection between the sets of the respective otopy classes of these maps, where by a local map we mean a compact perturbation of identity with a compact preimage of zero.
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Canonical perturbation theory for inhomogeneous systems of interacting fermions
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Generalized quazilinearization for systems of degenerate singular perturbation problem
PublikacjaPraca dotyczy ogólnej metody kwazilinearyzacji dla układów równań różniczkowych z parametrami.
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On the Nonlinear Effects of Magnetoacoustic Perturbations in a Perfectly Conducting Viscous and Thermoconducting Gas
PublikacjaNonlinear effects of planar and quasi-planar magnetosound perturbations are discussed. The plasma is as- sumed to be a Newtonian thermoconducting gas with infinite electrical conductivity permeated by a magnetic field orthogonal to the trajectories of gas particles. Generation of the non-wave modes (magnetoacoustic heating and streaming) in the field of periodic and aperiodic magnetoacoustic perturbations is discussed. The results...
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Magnetosonic Excitation of the Entropy Perturbations in a Plasma with Thermal Conduction Depending on Temperature
PublikacjaNonlinear excitation of the entropy perturbations by magnetosonic waves in a uniform and infinite plasma model is considered. The wave vector of slow or fast mode forms an arbitrary angle (0 B B ) with the equilibrium straight magnetic field, and all perturbations are functions of the time and longitudinal coordinate. Thermal conduction is the only factor which destroys isentropicity of wave perturbations and causes the nonlinear...
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On the Nonlinear Effects of Magnetoacoustic Perturbations in Optically Thin Quasi-Isentropic Plasmas
PublikacjaNonlinear effects of planar magnetosound perturbations in a plasma are discussed. Plasma is non-adiabatic due to optically thin radiation and external heating. For these reasons, thermal instability of a plasma may appear which makes it acoustically active. The plasma is assumed to be initially homogeneous ideal gas with infinite electrical conductivity permeated by a straight magnetic field which is orthogonal to the trajectories...
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Adaptive Human Behavior and Physiology
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Complex Adaptive Systems Modeling
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Relations between magnetosonic perturbations as an indicator of a magnetosonic exciter and equilibrium parameters of a plasma
PublikacjaThe thermodynamic relations between perturbation of pressure and pertur- bation of mass density and between components of velocity which specify a magnetosonic wave are theoretically studied. A planar flow with the wave vec- tor forming a constant angle with the equilibrium magnetic field is investigated. The theory considers deviation from the adiabaticity of a flow due to some kind of heating–cooling function and thermal conduction...
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Hysteresis curves and loops for harmonic and impulse perturbations in some non-equilibrium gases
PublikacjaEvolution of sound in a relaxing gas whose properties vary in the course of wave propagation, is studied. A relaxing medium may reveal normal acoustic properties or be acoustically active. In the first case, losses in acoustic energy lead to an increase in internal energy of a gas similarly as it happens in Newtonian fluids. In the second case, acoustic energy increases in the course of sound propagation, and the internal energy...
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Nonlinear Excitation of the Non-Wave Perturbations by the Magnetoacoustic Waves in the Non-Isentropic Plasma
PublikacjaNonlinear excitation of slow modes by the planar magnetosonic perturbations in a plasma is discussed. Plasma is an open system due to radiation and external heating. This may stipulate enhancement of wave perturbations and hence the acoustical activity of plasma. Plasma is assumed to be a homogeneous ideal gas with infinite electrical conductivity. The straight magnetic field is orthogonal to the velocity of fluid’s...
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Optimization of impedance measurements using ''chirp'' type perturbation signal
PublikacjaW pracy przedstawiono innowacyjny sposób pomiaru impedancji przy użyciu sygnału niestacjonarnego "chirp". W procesie akwizycji pobudzenia i odpowiedzi prądowej zastosowano zmienną częstotliwość próbkowania. Podejście takie pozwala zarówno na wielokrotne zmniejszenie ilości niezbędnych do otrzymania widma impedancyjnego rejestrowanych danych jak również upraszcza i przyspiesza proces obliczeniowy. Stwierdzono iż dokładność wyników...
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Optimization of impedance measurements using ‘chirp’ type perturbation signal
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Perturbation analysis of electric field around objects in sea water
PublikacjaThe paper presents an analytical approach to the perturbation analysis of electric field distribution caused by a sphere and an ellipsoid placed in a uniform electric field.
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Additive Manufacturing
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Topological degree for equivariant gradient perturbations of an unbounded self-adjoint operator in Hilbert space
PublikacjaWe present a version of the equivariant gradient degree defined for equivariant gradient perturbations of an equivariant unbounded self-adjoint operator with purely discrete spectrum in Hilbert space. Two possible applications are discussed.
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A Strategy to Locate Fixed Points and Global Perturbations of ODE’s: Mixing Topology with Metric Conditions
PublikacjaIn this paper we discuss a topological treatment for the planar system z' = f (t, z) + g(t, z) where f and g are T -periodic in time and g(t, z) is bounded. Namely, we study the effect of g(t, z) in two different frameworks: isochronous centers and time periodic systems having subharmonics. The main tool employed in the proofs consists of a topological strategy to locate fixed points in the class of orientation preserving embedding...
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Non-Adaptive Rotor Speed Estimation of Induction Machine in an Adaptive Full-Order Observer
PublikacjaIn the sensorless control system of an induction machine, the rotor speed value is not measured but reconstructed by an observer structure. The rotor speed value can be reconstructed by the classical adaptive law with the integrator. The second approach, which is the main contribution of this paper, is the non-adaptive structure without an integrator. The proposed method of the rotor speed reconstruction is based on an algebraic...
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Adaptive inertial shock-absorber
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A Framework for Adaptive and Integrated Classification
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Adaptive resolution simulation of liquid para-hydrogen: testing the robustness of the quantum-classical adaptive coupling
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On description of periodic magnetosonic perturbations in a quasi-isentropic plasma with mechanical and thermal losses and electrical resistivity
PublikacjaMagnetosonic periodic perturbations in a uniform and infinite plasma model are considered. Damping due to compressional viscosity, electrical resistivity, and thermal conduction are taken into account, as well as some heating–cooling function, which may destroy the isentropicity of wave perturbations. The wave vector forms arbitrary angle h with the equilibrium straight magnetic field, and all perturbations are functions...
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Simulating coherent light propagation in a random scattering materials using the perturbation expansion
PublikacjaMultiple scattering of a coherent light plays important role in the optical metrology. Probably the most important phenomenon caused by multiple scattering are the speckle patterns present in every optical imaging method based on coherent or partially coherent light illumination. In many cases the speckle patterns are considered as an undesired noise. However, they were found useful in various subsurface imaging methods such as...
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Adaptive Optimal Discrete-Time Output-Feedback Using an Internal Model Principle and Adaptive Dynamic Programming
PublikacjaIn order to address the output feedback issue for linear discrete-time systems, this work suggests a brand-new adaptive dynamic programming (ADP) technique based on the internal model principle (IMP). The proposed method, termed as IMP-ADP, does not require complete state feedback, merely the measurement of input and output data. More specifically, based on the IMP, the output control problem can first be converted into a stabilization...
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Advances in Data Science and Adaptive Analysis
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ACM Transactions on Autonomous and Adaptive Systems
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Self-Optimizing Adaptive Vibration Controller
PublikacjaThis 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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Adaptive CAD-Model Construction Schemes
PublikacjaTwo advanced surrogate model construction techniques are discussed in this paper. The models employ radial basis function (RBF)interpolation scheme or artificial neural networks (ANN) with a new training algorithm. Adaptive sampling technique is applied withrespect to all variables. Histograms showing the quality of the models are presented. While the quality of RBF models is satisfactory, theperformance of the ANN models obtained...
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Generalized adaptive notch smoothing revisited
PublikacjaThe 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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New Algorithms for Adaptive Notch Smoothing
PublikacjaThe problem of extraction/elimination of a nonstationary complex sinusoidal signal buried in noise is considered. This problem is usually solved using adaptive notch filtering (ANF)algorithms. It is shown that accuracy of signal estimation can be increased if the results obtained from ANF are further processed using a cascade of appropriately designed filters. The resulting adaptive notch smoothing (ANS) algorithms can be employed...
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Self-tuning adaptive frequency tracker
PublikacjaAn automatic gain tuning algorithm is proposed for a recently introduced adaptive notch filter. Theoretical analysis and simulations show that, under Gaussian random-walk type assumptions, the proposed extension is capable of adjusting adaptation gains of the filter so as to minimize the mean-squared frequency tracking error without prior knowledge of the true frequency trajectory. A simplified one degree of freedom version of...
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Adaptive Management Approach to an Infrastructure Project
PublikacjaThe paper presents an adaptive approach to project management, illustrated by the description of a case study, i.e., of a project whose aim was to develop the means and prepare the documentation for the revitalization of a railway line. The project itself was a major challenge for the implementers due to a novel and innovative subject thereof, including the construction of a railway line which takes place in a difficult terrain...
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Advantages of adaptive control in LP turbines.
PublikacjaW pracy przedstawiono wyniki obliczeń numerycznych dla ostatniego stopnia turbiny parowej, w którym kierownica posiadała mozliwośc adaptacji do zmiennego ciśnienia w kondensatorze. Adaptacyjność uzyskiwano porzez zmianę kąta ustawienia ruchomej krawędzi spływu (lotki) kierownicy. Wykazano korzysny wpływ tego typu regulacji zarówno na sprawność ostatniego stopnia jak i stopni poprzedzających.
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An adaptive fuzzy excitation control for turbogenerators.
PublikacjaOpracowano rozmyty układ regulacji turbogeneratora. Układ ten spełnia dwie funkcji: utrzymanie napięcia generatora synchronicznego do poziomu zadanego i tłumienia kołysań elektromechanicznych. Parametry rzomytego układu sterowania optymalizowano z wykorzystaniem algorytmów genetycznych.
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On the concept of estimation memory in adaptive filtering.
PublikacjaArtykuł przedstawia i omawia pojęcie pamięci estymacji, pozwalające na obiektywne porównanie właściwości śledzących różnych algorytmów adaptacyjnych filtracji.
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Perturbations of the hepatic proteome behind the onset of metabolic disorders in mouse offspring developed following embryo manipulation
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Variations in the near-surface atmospheric electric field at high latitudes and ionospheric potential during geomagnetic perturbations
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Active flux based adaptive and non-adaptive observer for sensorless interior permanent magnet synchronous machine drive
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Electrochemical sensor for measurement of volatile organic compounds employing square wave perturbation voltage
PublikacjaThe paper presents the results of investigation on a prototype sensor for measurement of benzaldehyde in air. Sensitivity and limit of quantification of the sensor were determined for different internal electrolyte using the square wave voltammetry (SWV) as a detection technique. The working and counter electrodes were made of platinum. Ionic liquids 1-hexyl, 3-methylimidazolium chloride,1-hexyl, 3-methylimidazolium bis (trifluoromethanesulfonyl)...
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Perturbation of cellular functions by topoisomerase II inhibitors: all roads lead to cell death?
PublikacjaPraca przeglądowa opisuje jakie funkcje mogą ulec zahamowaniu/zmianie pod wpływem działania inhibitorów topoizomerazy typu II w komórkach nowotworowych. W szczególności dyskutujemy jakie zmiany w szlakach sygnalizacji wewnątrzkomórkowej mogą prowadzić do zahamowania wzrostu oraz indukcji różnych rodzajów śmierci komórkowej i czy rodzaj śmierci komórkowej może decydować o skuteczności leków przeciwnowotoworowych, które hamują aktywność...
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New Method of Non-Linear Electrochemical Impedance Spectroscopy with an Amplitude-Modulated Perturbation Signal
PublikacjaThe paper presents a new method of non-linear electrochemical impedance spectroscopy (NLEIS), which allows fast and nondestructive evaluation of the corrosion rate and determination of the Tafel coefficients values for a corrosion system under investigation. This method employs amplitude modulation of the ac perturbation signal. The study demonstrated that it was possible to obtain impedance characteristic as a function of the...