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    Wyświetlanie 1-23 z 23
    Tytuł:
    A coupled system of fractional order integral equations in reflexive Banach spaces
    Autorzy:
    El-Sayed, A.M.A.
    Hashem, H.H.G.
    Powiązania:
    https://bibliotekanauki.pl/articles/963436.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Matematyczne
    Tematy:
    Weak solution
    Pettis-integral of fractional order integration
    Coupled system
    Opis:
    We present an existence theorem for at least one weak solution for a coupled system of integral equations of fractional order in reflexive Banach spaces relative to the weak topology.
    Źródło:
    Commentationes Mathematicae; 2012, 52, 1
    0373-8299
    Pojawia się w:
    Commentationes Mathematicae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Flexural vibration of coupled double-walled Carbon nanotubes conveying fluid under thermo-magnetic fields based on strain gradient theory
    Autorzy:
    Ghorbanpour Arani, A.
    Dashti, P.
    Amir, S.
    Yousefi, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/949348.pdf
    Data publikacji:
    2015
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    flexural vibration
    conveying fluid
    coupled system
    thermo-magnetic fields
    viscoelasticity
    Opis:
    The flexural vibration stability of a coupled double-walled viscoelastic carbon nanotube conveying a fluid based on the Timoshenko beam (TB) model is investigated. The coupled system is surrounded by an elastic medium which is simulated as Pasternak foundation. Van der Waals (vdW) forces between the inner and outer CNTs are taken into account based on the Lenard-Jones model. Using small scale theories, Hamilton’s principle and applying two dimensional (2D) magnetic field higher order governing equations are derived. The differential quadrature method (DQM) is applied to solve partial differential equations and investigate natural frequency of the system. The effects of viscoelastic constant, magnetic field with variable magnitudes and surface stresses on natural frequency of the structure are demonstrated in this study.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2015, 53, 4; 947-957
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On the weak solutions of a coupled system of Volterra--Stieltjes integral equations
    Autorzy:
    Alfadel, Masouda
    El-sayed, Ahmed
    Powiązania:
    https://bibliotekanauki.pl/articles/962154.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Matematyczne
    Tematy:
    Coupled system
    weak solution
    weakly Riemann--Stieltjes integral
    weakly relatively compact
    Opis:
    We present an existence theorem for at least one weak solution to a coupled system of Volterra--Stieltjes integral equations in a reflexive Banach space.
    Źródło:
    Commentationes Mathematicae; 2017, 57, 2; 143-151
    0373-8299
    Pojawia się w:
    Commentationes Mathematicae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dynamic modeling and analysis of helical gear-shaft-bearing coupled system
    Autorzy:
    Bai, Huan
    Song, Chaosheng
    Zhu, Caichao
    Wang, Yawen
    Ou, Zhuxiang
    Powiązania:
    https://bibliotekanauki.pl/articles/2055045.pdf
    Data publikacji:
    2020
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    gear-shaft-bearing coupled system
    dynamic characteristics
    rotating speed
    bearing clearance
    Opis:
    Considering bearing clearance, time-varying mesh stiffness, time-varying transmission error and shaft flexibility, a coupled gear-shaft-bearing dynamic model for a helical gear transmission is established. The influences of rotating speed, input torque load and bearing clearance on the dynamics are studied. Results show that the frequency and the magnitude of the peak response increase with the increase of load. As the bearing clearance increases, the amplitude of the dominant mesh frequency is significantly increased. Under lower speed, the clearance has a limited effect on the dynamic mesh force. However, under moderate and high speeds, the main peak response frequency of the dynamic mesh force is decreased as it increases.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2020, 58, 3; 743--756
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optimal Control of a Drying Process with Avoiding Cracks
    Autorzy:
    Galant, Alexander
    Grossman, Christian
    Scheffler, Michael
    Wensch, Jörg
    Powiązania:
    https://bibliotekanauki.pl/articles/1373542.pdf
    Data publikacji:
    2012
    Wydawca:
    Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
    Tematy:
    optimal control
    penalty barrier methods
    control constraints
    coupled parabolic system
    descretization
    Opis:
    The paper deals with the numerical treatment of the optimal control of drying of materials which may lead to cracks. The drying process is controlled by temperature, velocity and humidity of the surrounding air. The state equations dene the humidity and temperature distribution within a simplied wood specimen for given controls. The elasticity equation describes the internal stresses under humidity and temperature changes. To avoid cracks these internal stresses have to be limited. The related constraints are treated by smoothed exact barrier-penalty techniques. The objective functional of the optimal control problem is of tracking type. Further it contains a quadratic regularization by an energy term for the control variables (surrounding air) and barrier-penalty terms. The necessary optimality conditions of the auxiliary problem form a coupled system of nonlinear equations in appropriate function spaces. This optimality system is given by the state equations and the related adjoint equations, but also by an approximate projection onto the admissible set of controls by means of barrier-penalty terms. This system is discretized by nite elements and treated iteratively for given controls. The optimal control itself is performed by quasi-Newton techniques.
    Źródło:
    Schedae Informaticae; 2012, 21; 81-105
    0860-0295
    2083-8476
    Pojawia się w:
    Schedae Informaticae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Existence and stability analysis of nonlinear sequential coupled system of Caputo fractional differential equations with integral boundary conditions
    Autorzy:
    Zada, Akbar
    Yar, Muhammad
    Li, Tongxing
    Powiązania:
    https://bibliotekanauki.pl/articles/744661.pdf
    Data publikacji:
    2018
    Wydawca:
    Uniwersytet Pedagogiczny im. Komisji Edukacji Narodowej w Krakowie
    Tematy:
    Caputo fractional derivative
    Riemann–Liouville fractional integral
    coupled system
    existence
    uniqueness
    fixed point theorem
    Hyers–Ulam stability
    Źródło:
    Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica; 2018, 17
    2300-133X
    Pojawia się w:
    Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The control of drilling vibrations: A coupled PDE-ODE modeling approach
    Autorzy:
    Saldivar, B.
    Mondié, S.
    Ávila Vilchis, J. C.
    Powiązania:
    https://bibliotekanauki.pl/articles/331138.pdf
    Data publikacji:
    2016
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    drilling vibrations
    LMI approach
    ultimate boundedness
    coupled wave-ODE system
    Opis:
    The main purpose of this contribution is the control of both torsional and axial vibrations occurring along a rotary oilwell drilling system. The model considered consists of a wave equation coupled to an ordinary differential equation (ODE) through a nonlinear function describing the rock–bit interaction. We propose a systematic method to design feedback controllers guaranteeing ultimate boundedness of the system trajectories and leading consequently to the suppression of harmful dynamics. The proposal of a Lyapunov–Krasovskii functional provides stability conditions stated in terms of the solution of a set of linear and bilinear matrix inequalities (LMIs, BMIs). Numerical simulations illustrate the efficiency of the obtained control laws.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2016, 26, 2; 335-349
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Extremal solutions to a coupled system of nonlinear fractional differential equations with Caputo fractional derivatives
    Autorzy:
    Derbazi, Choukri
    Baitiche, Zidane
    Benchohra, Mouffak
    Graef, John R.
    Powiązania:
    https://bibliotekanauki.pl/articles/2052385.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
    Tematy:
    Caputo fractional derivative
    coupled system
    extremal solutions
    monotone iterative technique
    upper and lower solutions
    pochodna ułamkowa Caputo
    system sprzężony
    ekstremalne rozwiązania
    monotoniczna technika iteracyjna
    Opis:
    Using the well-known monotone iterative technique together with the method of upper and lower solutions, the authors investigate the existence of extremal solutions to a class of coupled systems of nonlinear fractional differential equations involving the $\psi$-Caputo derivative with initial conditions. As applications of this work, two illustrative examples are presented.
    Źródło:
    Journal of Mathematics and Applications; 2021, 44; 19-34
    1733-6775
    2300-9926
    Pojawia się w:
    Journal of Mathematics and Applications
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Examination of the Effect of a Sound Source Location on the Steady-State Response of a Two-Room Coupled System
    Autorzy:
    Meissner, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/177058.pdf
    Data publikacji:
    2011
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    coupled room system
    steady-state room response
    potential and kinetic energy densities
    localization of modes
    Opis:
    In this paper, the computer modelling application based on the modal expansion method is developed to study the influence of a sound source location on a steady- state response of coupled rooms. In the research, an eigenvalue problem is solved numerically for a room system consisting of two rectangular spaces connected to one another. A numerical procedure enables the computation of shape and frequency of eigenmodes, and allows one to predict the potential and kinetic energy densities in a steady-state. In the first stage, a frequency room response for several source positions is investigated, demonstrating large deformations of this response for strong and weak modal excitations. Next, a particular attention is given to studying how the changes in a source position influence the room response when a source frequency is tuned to a resonant frequency of a strongly localized mode.
    Źródło:
    Archives of Acoustics; 2011, 36, 4; 761-775
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The well-posedness of a swimming model in the 3-D incompressible fluid governed by the nonstationary Stokes equation
    Autorzy:
    Khapalov, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/330536.pdf
    Data publikacji:
    2013
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    swimming model
    coupled PDE/ODE system
    nonstationary Stokes equation
    sprzężony system PDE/ODE
    równanie Stokesa
    Opis:
    We introduce and investigate the well-posedness of a model describing the self-propelled motion of a small abstract swimmer in the 3-D incompressible fluid governed by the nonstationary Stokes equation, typically associated with low Reynolds numbers. It is assumed that the swimmer’s body consists of finitely many subsequently connected parts, identified with the fluid they occupy, linked by rotational and elastic Hooke forces. Models like this are of interest in biological and engineering applications dealing with the study and design of propulsion systems in fluids.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2013, 23, 2; 277-290
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Addendum to “The well-posedness of a swimming model in the 3-D incompressible fluid governed by the nonstationary Stokes equation”
    Autorzy:
    Khapalov, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/330456.pdf
    Data publikacji:
    2013
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    swimming model
    coupled PDE/ODE system
    nonstationary Stokes equation
    sprzężony system PDE/ODE
    równanie Stokesa
    Opis:
    In this addendum we address some unintentional omission in the description of the swimming model in our recent paper (Khapalov, 2013).
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2013, 23, 4; 905-906
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Theoretical analysis of the efficiency of a V2G wireless charger for electric vehicles
    Autorzy:
    Triviño, Alicia
    Gonzalez-Gonzalez, Jose M.
    Aguado, Jose A.
    Powiązania:
    https://bibliotekanauki.pl/articles/136256.pdf
    Data publikacji:
    2019
    Wydawca:
    EEEIC International Barbara Leonowicz Szabłowska
    Tematy:
    V2G
    wireless discharge
    losses
    efficiency
    electric vehicle
    inductively-coupled power system
    ICPT
    bidirectional
    wireless charging
    Opis:
    V2G (Vehicle-to-grid) technology will report important benefits for the operation and safety of the grid. In order to facilitate the expansion of the V2G technology in a future, it is recommended to offer the drivers with easy to use methods to charge and discharge their EV batteries. In this sense, wireless chargers are expected to play a relevant role in the future electrical networks as it reduces the users intervention. The development of this kind of system is still open to improve them in terms of their operation, their compliance and their control. An important issue for the evaluation of these systems is the efficiency, which measures the power losses occurring in the system. This paper addresses a deep study about the losses in a bidirectional wireless charger. Then, it provides with a mathematical model to characterize them. This model is validated by means of experimental results conducted in a 3.7-kW prototype.
    Źródło:
    Transactions on Environment and Electrical Engineering; 2019, 3, 1; 9-14
    2450-5730
    Pojawia się w:
    Transactions on Environment and Electrical Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical solution of a fractional coupled system with the Caputo-Fabrizio fractional derivative
    Autorzy:
    Mansouri, Ikram
    Bekkouche, Mohammed Moumen
    Ahmed, Abdelaziz Azeb
    Powiązania:
    https://bibliotekanauki.pl/articles/2202061.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
    Tematy:
    Caputo-Fabrizio fractional derivative
    fractional integral
    coupled system
    fractional differential equation
    fixed point
    Adomian decomposition method
    pochodna ułamkowa Caputo-Fabrizio
    całkowanie ułamkowe
    system sprzężony
    ułamkowe równanie różniczkowe
    punkt stały
    metoda dekompozycji Adomiana
    Opis:
    Within this work, we discuss the existence of solutions for a coupled system of linear fractional differential equations involving Caputo-Fabrizio fractional orders. We prove the existence and uniqueness of the solution by using the Picard-Lindel ̈of method and fixed point theory. Also, to compute an approximate solution of problem, we utilize the Adomian decomposition method (ADM), as this method provides the solution in the form of a series such that the infinite series converge to the exact solution. Numerical examples are presented to illustrate the validity and effectiveness of the proposed method.
    Źródło:
    Journal of Applied Mathematics and Computational Mechanics; 2023, 22, 1; 46--56
    2299-9965
    Pojawia się w:
    Journal of Applied Mathematics and Computational Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dynamics of multi-pendulum systems with fractional order creep elements
    Dynamika układów wielowahadłowych z efektem pełzania opisanym elementami ułamkowego rzędu
    Autorzy:
    Hedrih (Stevanovic), K. R.
    Powiązania:
    https://bibliotekanauki.pl/articles/280921.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    drgania
    układy wielowahadłowe
    coupled subsystems
    coupled dynamics
    multi-pendulum system
    Opis:
    A survey as a short review of author’s research results in area of dynamics of hybrid systems and analytical dynamics of discrete material particle system containing creep elements described by fractional order derivatives, is presented. Free vibrations of a multi-pendulum system intercoupled by standard light elements and different properties are considered. The corresponding system of an ordinary fractional order as well as integro-differential equations, described dynamics of the multi-pendulum system, are derived and analytically solved. For the case of one pendulum and two pendulum systems containing standard light creep elements with the stress-strain constitutive relation expressed by a fractional order derivative, ordinary differential equations are analytically solved. From the analytical solutions, for the case of the homogeneous two-pendulum system, it is visible that free vibrations under arbitrary initial conditions contain three modes, one pure periodic and two aperiodic expressed by time series expansions. The obtained analytical solution modes are numerically analysed and characteristic vibration modes for different kinetic parameters are graphically presented.
    W pracy zaprezentowano krótki przegląd rezultatów badań autora nad dynamiką układów hybrydowych i dyskretnych, złożonych z punktów materialnych sprzęgniętych standardowymi elementami odpowiadającymi za pełzanie w materiale i opisywanych pochodną ułamkowego rzędu. Rozważono drgania swobodne układów wielowahadłowych z elementami o różnych właściwościach zdefiniowanych równaniem pomiędzy stanem naprężenia a odkształcenia. Wyprowadzone równania różniczkowo-całkowe ułamkowego rzędu rozwiązano analitycznie. Przedstawiono szczegółowo przypadek układu z pojedynczym wahadłem i układu dwuwahadłowego zawierającego elementy pełzania opisane równaniem konstytutywnym stanu naprężenia i odkształcenia o rzędzie ułamkowym. Na podstawie otrzymanych rozwiązań analitycznych zauważono, że drgania swobodne wykazują charakter okresowy i nieokresowy, przy czym te ostatnie mają dwa różne przebiegi (w tym przypadku rozwiązanie podano w postaci rozwinięć w szeregi potęgowe). Wyniki badań teoretycznych i numerycznych różnego rodzaju drgań przy zmiennych parametrach kinetycznych tych układów przedstawiono graficznie.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2008, 46, 3; 483-509
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A multivariable multiobjective predictive controller
    Autorzy:
    Ben Aicha, F.
    Bouani, F.
    Ksouri, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/331360.pdf
    Data publikacji:
    2013
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    closed loop performance
    coupled multivariable system
    generalized predictive control
    multiobjective optimization
    weighted sum method
    NSGA-II
    układ wielowymiarowy
    sterowanie predykcyjne
    optymalizacja wielokryterialna
    metoda sumy ważonej
    Opis:
    Predictive control of MIMO processes is a challenging problem which requires the specification of a large number of tuning parameters (the prediction horizon, the control horizon and the cost weighting factor). In this context, the present paper compares two strategies to design a supervisor of the Multivariable Generalized Predictive Controller (MGPC), based on multiobjective optimization. Thus, the purpose of this work is the automatic adjustment of the MGPC synthesis by simultaneously minimizing a set of closed loop performances (the overshoot and the settling time for each output of the MIMO system). First, we adopt the Weighted Sum Method (WSM), which is an aggregative method combined with a Genetic Algorithm (GA) used to minimize a single criterion generated by the WSM. Second, we use the Non- Dominated Sorting Genetic Algorithm II (NSGA-II) as a Pareto method and we compare the results of both the methods. The performance of the two strategies in the adjustment of multivariable predictive control is illustrated by a simulation example. The simulation results confirm that a multiobjective, Pareto-based GA search yields a better performance than a single objective GA.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2013, 23, 1; 35-45
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    New coupled atmosphere-ocean-ice system COSMO-CLM/NEMO: assessing air temperature sensitivity over the North and Baltic Seas
    Autorzy:
    Van Pham, T.
    Brauch, J.
    Dieterich, C.
    Frueh, B.
    Ahrens, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/48930.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Instytut Oceanologii PAN
    Tematy:
    coupled atmosphere-ocean-ice system
    temperature sensitivity
    air temperature
    Baltic Sea
    North Sea
    regional climate modelling
    COSMO-CLM model
    Źródło:
    Oceanologia; 2014, 56, 2
    0078-3234
    Pojawia się w:
    Oceanologia
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An approach to suppress high-frequency resonance using model predictive and selective harmonic elimination combined strategy
    Autorzy:
    Chen, Sitong
    Chen, Xiaoqiang
    Wang, Ying
    Xiong, Ye
    Powiązania:
    https://bibliotekanauki.pl/articles/1841300.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    CRH5 EMUs and traction power supply coupled system
    high-frequency oscillation
    high speed railway
    model predictive control (MPC)
    selective harmonic elimination pulse-width modulation (SHEPWM)
    CRH5 EMU i system sprzężony z zasilaniem trakcyjnym
    oscylacja wysokiej częstotliwości
    kolej dużych prędkości
    kontrola predykcyjna modelu (MPC)
    selektywna eliminacja harmoniczna modulacja szerokości impulsu (SHEPWM)
    Opis:
    High-frequency resonance is a prominent phenomenon which affects the normal operation of the high-speed railway in China. Aiming at this problem, the resonance mechanism is analyzed first. Then, model predictive control and selective harmonic elimination pulse-width modulation (MPC-SHEPWM) combined control strategy is proposed, where the harmonics which cause the resonance can be eliminated at the harmonic source. Besides, the MPC is combined to make the current track the reference in transients. The proposed control has the ability to suppress the resonance while has a faster dynamic performance comparing with SHEPWM. Finally, the proposed MPC-SHEPWM is tested in a simulation model of CRH5 (Chinese Railway High-speed), EMUs (electric multiple units) and a traction power supply coupled system, which shows that the proposed MPC-SHEPWM approach can achieve the resonance suppression and shows a better dynamic performance.
    Źródło:
    Archives of Electrical Engineering; 2021, 70, 2; 415-430
    1427-4221
    2300-2506
    Pojawia się w:
    Archives of Electrical Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Supporting marine environment research by modeling
    Autorzy:
    Jakacki, Jaromir
    Przyborska, Anna
    Darecki, Mirosław
    Powiązania:
    https://bibliotekanauki.pl/articles/1955263.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Gdańska
    Tematy:
    Modeling-Baltic Sea
    coupled models
    regional models
    hydrodynamic modeling
    eBalticGrid system
    SatBaltic system
    Opis:
    The Centre of Informatics – Tri-City Academic Supercomputer and Network (CI TASK) was founded over twenty-five years ago, in 1994. It was a very important initiative undertaken as a result of rapid development of computer technology and one of its main goals was to integrate the computer resources of scientific communities in the Tri-City. CI TASKstarted to provide computing resources and the first steps in the world of high-performance computing must have been proved to be a significant challenge. The scientific community of the Institute of Oceanology has been cooperating with that computing centre since the very beginning.Currently, CI TASKprovides the widest set of tools and hardware that can be used for ocean modeling purposes. The main goal of this work is expression of appreciation and gratitude for the people who have contributed to the developing of this institution and helped in the work using their tools.CI TASK has been helpful in a great number of past and present tasks, however, in this paper we would like to present only three results of our work – a coupled ice-ocean model of the Baltic Sea, assessment of contamination for potential leak age from chemical munition dumped after the Second World War, and the currently operating SatBaltic system.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2018, 22, 4; 351--363
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Continuity of Solutions of Riccati Equations for the Discrete-Time Jlqp
    Autorzy:
    Czornik, A.
    Świerniak, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/908498.pdf
    Data publikacji:
    2002
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    automatyka
    coupled algebraic Ricatti equations
    jump parameter system
    quadratic control
    stochastic stabilizability
    observability
    robustness
    sensitivity
    Opis:
    The continuity of the solutions of difference and algebraic coupled Riccati equations for the discrete-time Markovian jump linear quadratic control problem as a function of coefficients is verified. The line of reasoning goes through the use of the minimum property formulated analogously to the one for coupled continuous Riccati equations presented by Wonham and a set of comparison theorems.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2002, 12, 4; 539-543
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    System identification and tuning of wireless power transfer systems with multiple magnetically coupled resonators
    Autorzy:
    Winges, J.
    Rylander, T.
    Petersson, C.
    Ekman, C.
    Johansson, L.-Å.
    McKelvey, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/136270.pdf
    Data publikacji:
    2017
    Wydawca:
    EEEIC International Barbara Leonowicz Szabłowska
    Tematy:
    wireless power transfer
    magnetically coupled resonators
    system identification
    tuning
    Bayesian estimation
    impedance matching
    charging electric vehicles
    Opis:
    We present a procedure for system identification and tuning of a wireless power transfer (WPT) system with four magnetically coupled resonators, where each resonator consists of a coil and a capacitor bank. The system-identification procedure involves three main steps: 1) individual measurement of the capacitor banks in the system; 2) measurement of the frequency-dependent two-port impedance matrix of the magnetically coupled resonators; and 3) determining the inductance of all coils and their corresponding coupling coefficients using a Bayesian approach. The Bayesian approach involves solving an optimization problem where we minimize the mismatch between the measured and simulated impedance matrix together with a penalization term that incorporates information from a direct measurement procedure of the inductance and losses of the coils. This identification procedure yields an accurate system model which we use to tune the four capacitance values to recover high system-performance and account for, e.g., manufacturing tolerances and coil displacement. For a prototype WPT system, we achieve 3.3 kW power transfer with 91% system efficiency over an air-gap distance of approximately 20 cm.
    Źródło:
    Transactions on Environment and Electrical Engineering; 2017, 2, 2; 86-92
    2450-5730
    Pojawia się w:
    Transactions on Environment and Electrical Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Simple environment for developing methods of controlling chaos in spatially distributed systems
    Autorzy:
    Korus, Ł.
    Powiązania:
    https://bibliotekanauki.pl/articles/907826.pdf
    Data publikacji:
    2011
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    stabilność układu
    wykładnik Lapunowa
    metoda Lyapunova
    coupled map lattice
    spatiotemporal chaos
    system stability
    Lyapunov exponents
    net direction phase
    Opis:
    The paper presents a simple mathematical model called a coupled map lattice (CML). For some range of its parameters, this model generates complex, spatiotemporal behavior which seems to be chaotic. The main purpose of the paper is to provide results of stability analysis and compare them with those obtained from numerical simulation. The indirect Lyapunov method and Lyapunov exponents are used to examine the dependence on initial conditions. The net direction phase is introduced to measure the symmetry of the system state trajectory. In addition, a real system, which can be modeled by the CML, is presented. In general, this article describes basic elements of environment, which can be used for creating and examining methods of chaos controlling in systems with spatiotemporal dynamics.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2011, 21, 1; 149-159
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Efficiency analysis of control algorithms in spatially distributed systems with chaotic behavior
    Autorzy:
    Korus, Ł.
    Powiązania:
    https://bibliotekanauki.pl/articles/331175.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    controlling spatiotemporal chaos
    coupled map lattice
    system stability
    Lyapunov exponent
    net direction phase
    stabilność układu
    wykładnik Lapunowa
    kierunek fazy
    Opis:
    The paper presents results of examination of control algorithms for the purpose of controlling chaos in spatially distributed systems like the coupled map lattice (CML). The mathematical definition of the CML, stability analysis as well as some basic results of numerical simulation exposing complex, spatiotemporal and chaotic behavior of the CML were already presented in another paper. The main purpose of this article is to compare the efficiency of controlling chaos by simple classical algorithms in spatially distributed systems like CMLs. This comparison is made based on qualitative and quantitative evaluation methods proposed in the previous paper such as the indirect Lyapunov method, Lyapunov exponents and the net direction phase indicator. As a summary of this paper, some conclusions which can be useful for creating a more efficient algorithm of controlling chaos in spatially distributed systems are made.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2014, 24, 4; 759-770
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analysis of geomechanical thermal effects caused by geothermal flows
    Analiza termalnych efektów geomechanicznych wywołanych przepływami geotermalnymi
    Autorzy:
    Ruciński, Piotr
    Szott, Wiesław
    Powiązania:
    https://bibliotekanauki.pl/articles/31343995.pdf
    Data publikacji:
    2023
    Wydawca:
    Instytut Nafty i Gazu - Państwowy Instytut Badawczy
    Tematy:
    naprężenia termalne
    geotermia wodna
    procesy transportu w ośrodku porowatym
    pozyskiwanie ciepła geotermalnego
    sprzężone modele złożowe H-T-M
    thermal stress
    water geothermal system
    transport processes in porous media
    geothermal energy
    production
    coupled reservoir models H-T-M
    Opis:
    The paper presents analysis of impact of temperature effects on change of stress state during production heat energy from geothermal reservoir. The aim of this paper was achieved by using a method of effective coupling between reservoir-thermal simulations and geomechanical simulations as a hydro-thermo-mechanical coupling (H-T-M). As a part of this project, two synthetic reservoir simulation models were built, a reservoir-thermal model and a geomechanical model. Well doublet was implemented into the reservoir simulation model, a cold water injection well and a hot water production well. The simulation scenarios of reservoir fluid and heat energy flows were calculated for the geothermal reservoir using Eclipse and Visage simulators under the supervision of Petrel software platform (Schlumberger). The results of coupled simulations included distributions of reservoir parameters (pressure and temperature) and geomechanical parameters (stresses and strains) as functions of time. The received results were used for stress state analysis of a geothermal reservoir under changes of pressure and temperature. Consequently, it was possible to determine the contribution of temperature and pressure effects to the change of the stress tensor. The performed analysis also allowed to show which of these factors played a dominant role in the process of producing geothermal energy. The analysis of geomechanical state was also supplemented with reservoir rock stability analysis using Mohr’s circle diagrams, with particular emphasis on temperature effects. Coupled scenario simulations allowed to determine the operating parameters for the maximum thermal energy production from the geothermal reservoir. The time variability of the produced water temperature was investigated for each simulation scenario. The following operational parameters were correlated: the rate of water injection/production and the temperature of the injected water with the resulting characteristics of the geothermal energy production process: the time of reducing the temperature of the produced water to the limiting value and the total amount of thermal energy. The relationships found between the aforementioned parameters allowed for the optimization of operational parameters in terms of obtaining the maximum amount of thermal energy.
    W pracy przedstawiono analizę wpływu efektów temperaturowych na zmianę stanu naprężeń w trakcie pracy złoża geotermalnego. Cel pracy został zrealizowany przy wykorzystaniu metody efektywnego sprzężenia symulacji złożowo-termalnych i geomechanicznych jako sprzężenia hydro-termo-mechanicznego (H-T-M). W ramach tego zadania zbudowano dwa syntetyczne złożowe modele symulacyjne, model przepływowo-termalny oraz model geomechaniczny. Do przepływowego modelu symulacyjnego zaimplementowano dublet otworów: jeden otwór zatłaczający zimną wodę i drugi – wydobywający gorącą wodę. Obliczenia różnych wariantów prognoz przepływu płynów złożowych i energii cieplnej dla złoża geotermalnego realizowano przy użyciu symulatorów Eclipse i Visage pod kontrolą oprogramowania Petrel firmy Schlumberger. W wyniku sprzężonych symulacji uzyskano rozkłady zmian parametrów złożowych (ciśnienia i temperatury) oraz zmian parametrów geomechanicznych (naprężeń i odkształceń) w funkcji czasu. Otrzymane wyniki obliczeń posłużyły do analizy stanu geomechanicznego złoża geotermalnego pod wpływem zmian ciśnienia i temperatury. Dzięki temu możliwe było określenie udziałów efektów temperaturowych i efektów ciśnieniowych w zmianie tensora naprężeń. Wykonane analizy pozwoliły również na wykazanie, który z tych czynników odgrywał dominującą rolę w trakcie pozyskiwania energii geotermalnej. Analiza stanu geomechanicznego została także uzupełniona o analizę stabilności skały złożowej z użyciem diagramów koła Mohra, ze szczególnym uwzględnieniem efektów temperaturowych. Sprzężone symulacje wariantowe pozwoliły na określenie optymalnych parametrów operacyjnych pracy złoża geotermalnego. Zbadano zmienność w czasie temperatury wydobywanej wody dla każdego wariantu symulacyjnego. Skorelowano ze sobą następujące parametry operacyjne: wydajność zatłaczania/odbioru wody i temperaturę zatłaczanej wody oraz wynikowe charakterystyki procesu pozyskiwania energii geotermalnej: czas redukcji temperatury wydobywanej wody do zadanej wartości i całkowitą ilość pozyskanej energii cieplnej. Znalezione zależności pomiędzy wspomnianymi parametrami pozwoliły na optymalizację parametrów operacyjnych pod kątem pozyskania maksymalnej ilości energii cieplnej.
    Źródło:
    Nafta-Gaz; 2023, 79, 1; 28-43
    0867-8871
    Pojawia się w:
    Nafta-Gaz
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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