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Search results for: f-type inverter
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Insulator to correlated metal transition inV1−xMoxO2
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Power Hardware-In-the-Loop Approach for Autonomous Power Generation System Analysis
PublicationThe article presents the Power Hardware-In-the-Loop (PHIL) dynamic model of a synchronous generator of 125 kVA for autonomous power generation system analysis. This type of system is typically composed of electrical energy sources in the form of several diesel generator units with synchronous machines, the main distribution switchboard and different loads. In modern power distribution systems, the proposed power management strategies...
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Pompownie dużej mocy z falownikiem wędrującym średniego napięcia
PublicationArtykuł zawiera rys rozwoju napędów przekształtnikowych w stacjach pomp, w szczególności regulacji wydatku kilku pomp, po kolei, przez jeden przemiennik częstotliwości. Omówiono podstawy teoretyczne zjawiska pola niestłumionego i napięcia resztkowego silników, które utrudniają szybkie przełączania silnika pompy pomiędzy zasilaniem regulowanym przez falownik a zasilaniem z sieci. Przedstawiono zasady transferu (przełączania) synchronicznego...
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Anomalous pressure dependence of acoustic phonons of AgGaSe2 investigated by inelastic neutron scattering to 4.3 GPa
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Emerging Role of Adenylate Kinase 4 as a Metabolic Player Regulating Cellular Hypoxic Responses in Pulmonary Cells
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Ni2X2 (X=pnictide, chalcogenide, or B) based superconductors
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Simulation model of IPMSM drive with rotor position estimator
PublicationThe paper presents a simulation model of electric drive consisting of: IPMSM motor, inverter and digital controller. The model was designed in Mathlab/Simulink. By modelling of the controller its discrete operation was taken into account in order to simulate precisely a specific sensorless control algorithm. A method for estimation of angular rotor position was proposed. Its mathematical algorithm was explained and errors were...
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Macro-elements and Model Order Reduction for Efficient Three-Dimensional FEM Analysis
PublicationAn efficient model order reduction (MOR) methodology for three dimensional vector finite element method (FEM) is developed to accelerate simulations of the structures containing features that cause strong variations of mesh density. As the result of presented algorithm, FEM subsystems of equations corresponding to the selected refined region are converted into a very compact sets of linear equations, called macro-elements.Numerical...
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Przekształtniki tranzystorowe działające w trybie prądu trójkątnego
PublicationPrzekształtniki oparte na węgliku krzemu mogą być analizowane jako źródła napięcia lub prądu niezależnie od topologii przy odpowiednich parametrach filtru wyjściowego. Szczególnie interesujące są falowniki napięcia działające w trybie prądu trójkątnego. W referacie przedstawiono sterowanie trójfazowym falownikiem napięcia posiadającym właściwości źródła prądu. Pokazano, jak dobrać parametry filtru wyjściowego falownika. Oceniono...
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Structural, physicochemical and anticancer study of Zn complexes with pyridyl-based thiazolyl-hydrazones
PublicationThiazolyl-hydrazones (THs) exhibit a wide spectrum of biological activity that can be enhanced by complexation with various metal ions. Zn(II) complexes with α-pyridine-1,3-TH ligands may represent an alternative to the standard platinum-based chemotherapeutics. In addition, they show photoluminescence properties and thus can be regarded as multifunctional materials. In this study, we synthesized and characterized three neutral...
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Seismic damage diagnosis in adjacent steel and RC MRFs considering pounding effects through improved wavelet-based damage-sensitive feature
PublicationThis paper aims to propose complex Morlet (cmorfb-fc) wavelet-based refined damage-sensitive feature (rDSF) as a new and more precise damage indicator to diagnose seismic damages in adjacent steel and Reinforced Concrete (RC) Moment Resisting Frames (MRFs) assuming pounding conditions using acceleration responses. The considered structures include 6- and 9-story steel and 4- and 8-story RC benchmark...
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Homoclinic solutions for a class of the second order Hamiltonian systems
PublicationW niniejszej pracy badamy istnienie orbit homoklinicznych dlaukładu Hamiltonowskiego drugiego rzędu: q^{..} + V_{q}(t,q) = f(t), gdzie V z iloczynu kartezjańskiego R x R^{n} do R jest postaciV(t,q) = -K(t,q) + W(t,q). Zakładamy, ze V jest T-okresowe ze względuna zmienną t, K spełnia tzw. ''pinching'' warunek, W jest superliniowew nieskończoności, a norma f w L^{2} jest wystarczająco mała.Orbitę homokliniczną takiego układu znajdujemy...
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Analytical fluctuation enhanced sensing by resistive gas sensors
PublicationResistance fluctuations across polarised resistive gas sensors were studied in detail to evaluate sensor working conditions for detecting methane and ammonia at various concentrations. The 1/f noise component typically dominates other noise sources up to a few kHz and can be utilised to improve gas selectivity when compared with measurements of the sensor DC resistance. The Arrhenius plot was created and the activation energy for...
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Mechanical and Microstructural Characterization of TIG Welded Dissimilar Joints between 304L Austenitic Stainless Steel and Incoloy 800HT Nickel Alloy
PublicationIn this article, the mechanical properties and microstructure of 304L austenitic stainless steel/Incoloy 800HT nickel alloy dissimilar welded joints are investigated. The joints were made of 21.3 mm × 7.47 mm tubes using the TIG process with the use of S Ni 6082 nickel filler metal. No welding imperfections were found and high strength properties of joints were obtained, meeting the assumed acceptance criteria of the product’s...
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Fault diagnosis of analog piecewise linear circuits based on homotopy
PublicationArtykuł opisuje weryfikację metodą diagnostyki analogowych układów odcinkowo-liniowych opartą na podejściu homotopijnym. Homotopia przekształca jedną funkcję f(x) w inną funkcję g(x) poprzez zmianę parametru homotopii tî[0,1]. Ścieżka homotopijna pokazuje drogę od punktu x0 z dziedziny funkcji f(x) do odpowiadającego mu punktu x* funkcji g(x). Idea metody zakłada wykorzystanie funkcji f(x) do opisu diagnozowanego układu w stanie...
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Compensation of Dead Time Effects for Shunt Active Power Filters
PublicationThe paper presents a comprehensive approach to the compensation of the grid current distortion for shunt active power filter systems. Four different sources of current distortion are addressed: imperfect grid synchronization caused by the distortion in the grid voltages, time delays in the estimation of compensating currents and grid voltages, fluctuations of the dc bus voltage, and the distortion of inverter output voltages due...
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Pulse-Width Modulation of Power Electronic DC–AC Converter
PublicationThe Second Edition of High Performance Control of AC Drives with Matlab®/Simulink delivers an updated and thorough overview of topics central to the understanding of AC motor drive systems. The book includes new material on medium voltage drives, covering state-of-the-art technologies and challenges in the industrial drive system, as well as their components, and control, current source inverter-based drives, PWM techniques for...
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CrossTalk opposing view: Which technique for controlling resistant hypertension? Carotid chemoreceptor denervation/modulation
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Can we reduce the stigmatisation experience with psychosocial interventions? An investigation of the meeting centre support programme impact on people with cognitive impairments
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Microbeam radiation therapy: Tissue dose penetration and BANG-gel dosimetry of thick-beams’ array interlacing
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Effect of Maximal Apnoea Easy-Going and Struggle Phases on Subarachnoid Width and Pial Artery Pulsation in Elite Breath-Hold Divers
PublicationPurpose: The aim of the study was to assess changes in subarachnoid space width (sas-TQ), the marker of intracranial pressure (ICP), pial artery pulsation (cc-TQ) and cardiac contribution to blood pressure (BP), cerebral blood flow velocity (CBFV) and cc-TQ oscillations throughout the maximal breath hold in elite apnoea divers. Non-invasive assessment of sas-TQ and cc-TQ became possible due to recently developed method based on...
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Hybrid battery based on arylated carbon nanotubes and laccase
PublicationSingle-walled carbon nanotubes (SWCNT) were covalently modified with anthracene and anthraquinone and used for the construction of cathodes for biocatalytic reduction of dioxygen. The nanotubes with aromatic groups casted onto the electrode increased the working surface of the electrode and enabled efficient direct electron transfer (DET) between the enzyme and the electrode. The aryl groups enter the hydrophobic pocket of the...
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Valence and lowest Rydberg electronic states of phenol investigated by synchrotron radiation and theoretical methods
PublicationWe present the experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectra of phenol covering for the first time the full 4.3–10.8 eV energy-range, with absolute cross sections determined. Theoretical calculations on the vertical excitation energies and oscillator strengths were performed using time-dependent density functional theory and the equation-of-motion coupled cluster method restricted to single and double...
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Zastosowanie analizy szeregów czasowych do oceny zanieczyszczenia powietrza atmosferycznego w rejonie Trójmiasta. Application of time series analysis on air quality assessment in the region of Tricity
PublicationNa podstawie analizy wyników pomiarów poziomów stężenia: NO3-, SO42-, F- ,Cl-, NH4+, PO43-, Ca2+, K+, Mg2+ oraz pomiarów pH i przewodności elektrolitycznej próbek wód opadowych na terenie Trójmiasta z zastosowaniem techniki analizy szeregów czasowych wykazano, że cykliczne wahania poziomów depozycji SO42-, F-, NO3- i Ca2+ w próbkach są skorelowane z cyklicznymi 9 zmianami przeważających kierunków wiatrów. Analiza struktury szeregów...
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Electric field-assisted dissociation of singlet excitons in tris-(8-hydro-xyquinolinato)aluminium (III)
PublicationW pracy podano szczegółowemu badaniu kompleks organo-metaliczny 8-hydroksy-chinoliny i aluminium (ALq3) metodą pomiaru fotopądów i elektromodulacji luminescencji. Stwierdzono, że w obszarze wysokich pól elektrycznych (F>105 V/cm) ładunek wytwarzany jest w procesie dysocjacji wzbudzonych stanów single-towych. Wyjaśnienie przebiegów prądowych w zakresie niskich pól elektrycznych (F<105 V/cm) wymagało włączenia zjawiska rekombinacji...
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Comprehensive compensation of grid current distortion by shunt active power filters
PublicationThe paper presents a comprehensive approach to the compensation of grid current distortion in shunt active power filter systems. Four sources of current distortion are addressed: imperfect grid synchronization caused by the distortion in the grid voltages, time delays in the evaluation of grid voltages and computation of compensating currents, fluctuations of the dc bus voltage, and the distortion of inverter output voltages due...
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Modular multipulse voltage source inverters with integrating coupled reactors
PublicationA novel approach to the voltage source inverters (VSI) construction is presented in the paper. The invented inverter structures allow to operate several DC/AC converters in parallel resulting in lower voltage distortions at extremely low switching frequency. The research presented in the paper describes such a parallel operation of the VSI’s which is possible thanks to the use of coupled inductors. The eighteen-pulse and twenty-four-pulse...
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Non-toxic fluorine-doped TiO2 nanocrystals from TiOF2 for facet-dependent naproxen degradation
PublicationIn the present study, the photocatalytic degradation of naproxen (NPX), which is a nonsteroidal anti-inflammatory drug (NSAID), frequently detected in drinking water, was investigated. The F-doped TiO2 with defined morphology was successfully obtained from TiOF2 and applied for photocatalytic degradation under UV-vis and visible light. All samples were characterised by X-ray diffraction, scanning electron microscopy, X-ray photoelectron...
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Chemical pollution and toxicity of water samples from stream receiving leachate from controlled municipal solid waste (MSW) landfill
PublicationThe present study was aimed to determine the impact of municipal waste landfill on the pollution level of surface waters, and to investigate whether the choice and number of physical and chemical parameters monitored are sufficient for determining the actual risk related to bioavailability and mobility of contaminants. In 2007–2012, water samples were collected from the stream flowing through the site at two sampling locations,...
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Achieving Efficient and Stable Deammonification at Low Temperatures—Experimental and Modeling Studies
PublicationThe short-term effects of temperature on deammonification sludge were evaluated in a laboratory-scale sequencing batch reactor (SBR). Mathematical modeling was used for further evaluations of different intermittent aeration strategies for achieving high and stable deammonification performance at decreasing temperatures. As for the biomass cultivated at high temperatures (e.g., 30 C), a higher temperature dependency (the adjusted...
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Existence of Two Periodic Solutions to General Anisotropic Euler-Lagrange Equations
PublicationAbstract. This paper is concerned with the following Euler-Lagrange system d/dtLv(t,u(t), ̇u(t)) =Lx(t,u(t), ̇u(t)) for a.e.t∈[−T,T], u(−T) =u(T), Lv(−T,u(−T), ̇u(−T)) =Lv(T,u(T), ̇u(T)), where Lagrangian is given by L=F(t,x,v) +V(t,x) +〈f(t),x〉, growth conditions aredetermined by an anisotropic G-function and some geometric conditions at infinity.We consider two cases: with and without forcing termf. Using a general version...
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Parseval Wavelet Frames on Riemannian Manifold
PublicationWe construct Parseval wavelet frames in L 2 (M) for a general Riemannian manifold M and we show the existence of wavelet unconditional frames in L p (M) for 1 < p < ∞. This is made possible thanks to smooth orthogonal projection decomposition of the identity operator on L 2 (M), which was recently proven by Bownik et al. (Potential Anal 54:41–94, 2021). We also show a characterization of Triebel–Lizorkin F sp,q (M) and Besov B...
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Comparison of the adaptive implementation and evaluation of the Meeting Centers Support Program for people with dementia and their family carers in Europe; study protocol of the MEETINGDEM project
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Conversion of waste biomass to designed and tailored activated chars with valuable properties for adsorption and electrochemical applications
PublicationWaste biomass, a renewable energy source, is inexpensive material that has great potential in sorp-tion and electrochemical application. The selected waste materials (corncobs, coconut shells, wal-nuts, and pistachio husks) allow to close the production cycle and enable material recycling, which are important aspects in the hierarchy of waste management. The proposed methodology for pro-duction and activation of biochars can be...
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Porównanie własności smarnych wody, emulsji oleju w wodzie typu HFA-E oraz oleju Total Azolla 46 jako czynników roboczych w układach hydraulicznych = Comparison of the lubricant property of water oil-in-water emulsion type HFA-E and oil total Azolla 46 as working liquids in hydraulic systems
PublicationW artykule scharakteryzowano i opisano wyniki badań własności smarnych wody destylowanej, 1% emulsji oleju w wodzie typu HFA-E sporządzonej na bazie koncentratu do tworzenia emulsji Isosynth VH110BF, oleju Total Azolla 46 oraz, w celach porównawczych, samego koncentratu Isosynth VH110BF. Przedstawiono również wyniki badań powierzchniowego zużycia zmęczeniowego (pittingu), dla wyżej wymienionych czynników smarnych. Emulsja oleju...
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Wybrane reakcje kwasu neopentylidenofosforoditiowego oraz jego zastosowanie do otrzymywania niesymetrycznie podstawionego wiązania disulfidowego lub sulfidowego.
PublicationŁatwo dostępne mieszane bezwodniki fosforoditio-tiokarboksylowe są doskonałymi, chemoselektywnymi odczynnikami tioacylującymi azotowe lub siarkowe nukleofile w obecności grupy hydroksylowej. Takie właściwości tych bezwodników umożliwiły otrzymywanie hydroksy tioamidów, hydroksy ditioestrów i kwasów tiohydroksamowych z substratów zawierających niechronioną grupę hydroksylową. Natomiast, N,N-dipodstawione oraz N-podstawione zatłoczone...
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Electronic structure and magnetism of samarium and neodymium adatoms on free-standing graphene
PublicationThe electronic structure of selected rare-earth atoms adsorbed on a free-standing graphene was investigated using methods beyond the conventional density functional theory (DFT+U, DFT +HIA, and DFT+ED). The influence of the electron correlations and the spin-orbit coupling on the magnetic properties has been examined. The DFT+U method predicts both atoms to carry local magnetic moments (spin and orbital) contrary to a nonmagnetic...
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Synthesis, structural and spectroscopic properties of asymmetric schiff bases derived from 2,3-diaminopyridine
PublicationTwo Schiff base derivatives, 4-(2-amino-3-pyridyliminomethyl)phenol (I) and 3-(2-amino-3- pyridyliminomethyl)nitrobenzene (II ), were synthesised and characterised by spectroscopy. The structure of I was determined by single crystal X-ray diffraction studies. The asymmetric Schiff base derived from 2,3-diaminopyridine selectively recognise transition and heavy metal cations, and some anion. Ligands I and II form stable complexes...
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Sensorless algorithm for sustaining controllability of IPMSM drive in electric vehicle after resolver fault
PublicationThis paper presents a sensorless algorithm designated for the emergency control of an interior permanent magnet synchronous motor (IPMSM) drive in electric or hybrid vehicle. The algorithm is based on analysing the derivatives of motor phase currents measured over the duration of particular inverter states. The method is computationally simple and does not require additional hardware since the derivatives are measured indirectly....
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Estimation of interior-permanent-magnet-synchronous-motor rotor position by analysis of phase-current derivatives
PublicationThis paper describes an algorithm for estimation of IPMSM rotor angular position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Calculation of the motor position is performed in every PWM cycle. The standard SV-PWM method is used to determine...
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Possibility of Fault Detection in Sensorless Electric Drives
PublicationThe work presents a fault detection method for an induction motor drive system with inverter output filter. This approach make use of a load torque state observer, which complete structure is presented along with the used control structure. Moreover, the demonstrated drive system operates without rotor speed measurement in conjunction with the multiscalar control. The verification of the demonstrated idea was performed on an experimental...
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Development and performance analysis of a novel multiphase doubly-fed induction generator
PublicationThis paper presents the research into the design and performance analysis of a novel five-phase doubly-fed induction generator (DFIG). The designed DFIG is developed based on standard induction motor components and equipped with a five-phase rotor winding supplied from the five-phase inverter. This approach allows the machine to be both efficient and reliable due to the ability of the five-phase rotor winding to operate during...
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A Review of Reduction Methods of Impact of Common-Mode Voltage on Electric Drives.
PublicationIn this survey paper, typical solutions that focus on the reduction in negative effects resulting from the common-mode voltage influence in AC motor drive applications are re-examined. The critical effectiveness evaluation of the considered methods is based on experimental results of tests performed in a laboratory setup with an induction machine fed by an inverter. The capacity of a common-mode voltage level reduction and voltage...
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Feliks Koneczny o cywilizacjach
PublicationArtykuł przedstawia zarys teorii cywilizacji opracowanej przez Feliksa Konecznego (1862-1949). Teoria ta zakłada, że najdoskonalszą formą cywilizacji jest cywilizacja łacińska oparta na religii katolickiej. W artykule wskazano również na kontekst idologiczny teorii F. Koniecznego.
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Differential inequalities with initial time difference.
PublicationUzyskano pewne wyniki porównawcze pomiędzy rozwiązaniami nierówności różniczkowych startujących z różnych punktów początkowych. O nieliniowej funkcji f (związanej z zagadnieniem) zakładano jednostronny warunek Lipschitza. Podano pewne zastosowanie otrzymanych wyników. Sformułowano też pewne warunki dotyczące stabilności.
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Solution conformational study of Scyliorhinin I analogues with conformational constraints by two-dimensional NMR and theoretical conformational analysis
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Photophysics of Soret-Excited Tin(IV) Porphyrins in Solution
PublicationThe photophysics of low-chlorin tin(IV) tetraphenylporphyrin dihydroxide, a core building block for axially substituted supramolecular tin porphyrin constructs, has been studied in a variety of hydrogen-bonding, nonpolar, and aprotic polar solvents using steady-state, nanosecond, and femtosecond time-resolved emission, and femtosecond time-resolved absorption methods. In hydrogen-bonding solvents the metalloporphyrin exists as...
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Effects of consecutive apneas on pial artery pulsation and subarachnoid width in healthy subjects
PublicationHypercapnia is known to dilate the pial artery, disrupt cerebral autoregulation and increase pial artery pulsation. The cerebral blood flow velocity (CBFV) response to hypercapnia is biphasic. Below the threshold for the increase of blood pressure (BP) with carbon dioxide partial pressure (pCO2), the CBFV measurement reflects vascular reactivity to pCO2 alone at a constant BP. Above this threshold, the CBFV measurement provides...
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Systems of differential inequalities with initial time difference.
PublicationPewne twierdzenia porównawcze są formułowane dla takich zagadnień.O funkcji F występującej po prawej stronie nierówności różniczkowej zakłada się, że spełnia własności kwasimonotoniczności. Sformułowanorównież twierdzenia o istnieniu ekstremalnych rozwiązań dla odpowiednich równań różniczkowych pierwszego rzędu z odchylonymi argumentami.
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Modelowanie szumów RTS
PublicationPrzytoczono charakterystyczne parametry szumu wybuchowego (Random Telegraph Signal, RTS). Przedstawiono algorytm programowego generatora szumów RTS. Algorytm został wyposażony w możliwość dodawania do wygenerowanych impulsów RTS szumu białego oraz szumu typu 1/f. Przedstawiono przykładowe realizacje wygenerowanych przebiegów.