Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "evolution equation" wg kryterium: Wszystkie pola

  Lista filtrów
Wyrównaj
Wyświetlanie 1-25 z 26
Tytuł:
Problem with integral condition for evolution equation
Autorzy:
Kalenyuk, P. I.
Kuduk, G.
Kohut, I. V.
Nytrebych, Z. M.
Powiązania:
https://bibliotekanauki.pl/articles/357782.pdf
Data publikacji:
2015
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
analiza funkcjonalna
przestrzeń Banacha
równania ewolucyjne
równania różniczkowe
functional analysis
Banach space
evolution equation
integral conditions
differential-symbol method
Opis:
We propose a method of solving the problem with non-homogeneous integral condition for homogeneous evolution equation with abstract operator in a linear space H. For right-hand side of the integral condition which belongs to the special subspace H ⊆ L, in which the vectors are represented using Stieltjes integrals over a certain measure, the solution of the problem is represented in the form of Stieltjes integral over the same measure.
Źródło:
Journal of Mathematics and Applications; 2015, 38; 71-76
1733-6775
2300-9926
Pojawia się w:
Journal of Mathematics and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractional evolution equation nonlocal problems with noncompact semigroups
Autorzy:
Zhang, X
Chen, P.
Powiązania:
https://bibliotekanauki.pl/articles/254893.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
fractional evolution equation
mild solution
nonlocal condition
Co-semigroup
condensing maps
measure of noncompactness
Opis:
This paper is concerned with the existence results of mild solutions to the nonlocal problem of fractional semilinear integro-differential evolution equations. New existence theorems are obtained by means of the fixed point theorem for condensing maps. The results extend and improve some related results in this direction.
Źródło:
Opuscula Mathematica; 2016, 36, 1; 123-137
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Existence of the fundamental solution of a second order evolution equation
Autorzy:
Bochenek, Jan
Powiązania:
https://bibliotekanauki.pl/articles/1294733.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
evolution problem
stable family of operators
stable approximations of the evolution operator
fundamental solution
Cauchy problem
uniformly correct Cauchy problem
Opis:
We give sufficient conditions for the existence of the fundamental solution of a second order evolution equation. The proof is based on stable approximations of an operator A(t) by a sequence ${A_n(t)}$ of bounded operators.
Źródło:
Annales Polonici Mathematici; 1997, 66, 1; 15-35
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized method of Lie-algebraic discrete approximations for solving Cauchy problems with evolution equation
Autorzy:
Kindybaliuk, A.
Powiązania:
https://bibliotekanauki.pl/articles/122439.pdf
Data publikacji:
2014
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
generalized method of Lie-algebraic discrete approximations
dynamical systems
evolution equation
finite dimensional quasi representation
approximations
Lagrange’s polynomial
factorial convergence
układy dynamiczne
aproksymacje
wielomian Lagrange'a
Opis:
We consider solving the Cauchy problem with an abstract linear evolution equation by means of the Generalized Method of Lie-algebraic discrete approximations. Discretization of the equation is performed by all variables in equation and leads to a factorial rate of convergence if Lagrange interpolation is used for building quasi representation of differential operator. The rank of a finite dimensional operator and approximation properties have been determined. Error estimations and the factorial rate of convergence have been proved.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2014, 13, 2; 51-62
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of concrete life under coupled dry and wet-sulfate erosion based on damage evolution equation
Autorzy:
Nie, Nan
Powiązania:
https://bibliotekanauki.pl/articles/28327950.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Opis:
In a corrosive environment with coupled dry-wet-sulfate action, concrete structures are susceptible to erosion by sulfate ions, which seriously affects the safe operating life. To forecast the operational lifetime of concrete below the influence of the dry-wet cycle and sulfate erosion environment, four different admixtures of polypropylene fiber: 0, 0.6, 0.9, and 1.2 kg/m3, were incorporated into concrete specimens, and indoor accelerated tests were designed to observe the macroscopic and microscopic deterioration law analysis of concrete specimens; using the precept of damage mechanics, the damage of concrete under solubility cycle was established. The damage evolution equation of concrete under freeze-thaw cycles was established and the operational life of concrete was predicted. The results showed that the overall mass loss rate of concrete specimens increased with the number of tests, and the relative energetic modulo decreased with the number of tests; the pore change pattern, microstructure, and internal material composition of specimens under different working conditions were obtained by using NMR scanning technique, SEM electron microscope scanning technique and XRD physical phase analysis technique. The damage evolution equation shows that adding a certain amount of polypropylene fiber to concrete can improve the working life of concrete under dry and wet connected sulfate assault.
Źródło:
Archives of Civil Engineering; 2023, 69, 4; 679--692
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solitary wave solution to the nonlinear evolution equation in cascaded quadratic media beyond the slowly varying envelope approximations
Autorzy:
Sarma, A K
Biswas, A.
Powiązania:
https://bibliotekanauki.pl/articles/174484.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
solitons
integrability
exact solution
cascaded quadratic media
Opis:
We report an exact bright and dark soliton solution to the nonlinear evolution equation derived by MOSES and WISE (Phys. Rev. Lett. 97, 2006, 073903) for cascaded quadratic media beyond the slowly varying envelope approximations. The integrability aspects of the model are addressed. The travelling wave hypothesis as well as the ansatz method are employed to obtain an exact 1-soliton solution. Both bright and dark soliton solutions are obtained. The corresponding constraint conditions are obtained in order for the soliton solutions to exist.
Źródło:
Optica Applicata; 2014, 44, 2; 205-212
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On interaction between damage growth and material stiffness in 3D structures
Autorzy:
Mika, P.
Powiązania:
https://bibliotekanauki.pl/articles/279694.pdf
Data publikacji:
1999
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
damage mechanics
evolution equation
material stiffness
Opis:
Deterioration of material properties; such as, rupture toughness, strength, and rigidity as well as lifetime reductions are modelled by a symmetric second order damage tensor introduced into the constitutive description, when employing the theory of tensor function representations. The growth of damage and state failure are described by a one parameter model of damage evolution and a three parameter failure criterion. The constitutive description for different modes of failure frontpropagation is of particular interest in this study. The comparision between solutions obtained by means of two different physical models; i.e., the linear elastic and linear elastic with damages ones, respectively, has been presented. In both cases the stress redistribution due to geometrrical changes of the structure induced by the crack propagation has been considered. Numerical calculations have been made employing the ABAQUS programme, Runge--Kutta procedures for integrationof the evolution equations, standard methods of matrix division in LU decomposition and Gauss method for solving the set of linear equations.
Procesy degradacji własności materiału, takich jak wytrzymałość, sztywność i redukcja czasu twrałości są modelowane przez symetryczny tensor uszkodzeń drugiego rzędu wprowadzony do opisu konstytutywnego z zastosowaniem teorii reprezentacji funkcji tensorowych. Wzrost uszkodzeń oraz stan zniszczenia są opisywane przez jednoparametrowe równanie evolucji oraz trójparametrowe kryterium zniszczenia. W pracy przedstawiono różne formy propagacji frontu zniszczenia w odniesieniu do opisu konstytutywnego. W tym kontekście dokonano porównania rozwiązań otrzymanych z zastosowaniem dwu odmiennych modeli fizycznych: liniowo sprężystego i liniowo sprężystego z uszkodzeniami. W obydwu przypadkach rozważana jest redystrybucja naprężeń spowodowana zmianami geometrycznymi konstrukcji wywołanymi propagacją zarysowań. W obliczeniach numerycznych odwołano się do programu ABAQUS, procedur Rungego--Kutty w całkowaniu równania ewolucji oraz standardowych metod rozkładu macierzy na górno-- i dolno--trójkątną, a w zakresie rozwiązywania układu równań algebraicznych -- do metody Gaussa.
Źródło:
Journal of Theoretical and Applied Mechanics; 1999, 4; 755-778
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Asymptotical Stability of a Dynamic System With Structural Damping
Autorzy:
Hou, X.
Powiązania:
https://bibliotekanauki.pl/articles/908219.pdf
Data publikacji:
2003
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
matematyka
dynamic systems
evolution equation
asymptotic stability
Opis:
A dynamic system with structural damping described by partial differential equations is investigated. The system is first converted to an abstract evolution equation in an appropriate Hilbert space, and the spectral and semigroup properties of the system operator are discussed. Finally, the well-posedness and the asymptotical stability of the system are obtained by means of a semigroup of linear operators.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2003, 13, 2; 131-138
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Second order evolution differential functional equations with infinite delay
Autorzy:
Człapiński, Tomasz
Karpowicz, Adrian
Powiązania:
https://bibliotekanauki.pl/articles/962858.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Measure of noncompactness
second order evolution equation
infinite delay
Opis:
We consider a second order semilinear functional evolution equation with infinite delay in a Banach space. We prove the existence of mild solutions for this equation using the measure of noncompactness technique and the Schauder fixed point theorem.
Źródło:
Commentationes Mathematicae; 2018, 58, 1-2; 93-104
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fourth order nonlinear evolution equation for interfacial gravity waves in the presence of air flowing over water and a basic current shear
Autorzy:
Majumder, D. P.
Dhar, A. K.
Powiązania:
https://bibliotekanauki.pl/articles/265668.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
nonlinear evolution equation
basic current shear
Stokes gravity wave
równania nieliniowe
przepływy Stokes'a
grawitacja
Opis:
A fourth order nonlinear evolution equation, which is a good starting point for the study of nonlinear water waves as first pointed out by Dysthe (1979) is derived for gravity waves propagating at the interface of two superposed fluids of infinite depth in the presence of air flowing over water and a basic current shear. A stability analysis is then made for a uniform Stokes gravity wave train. Graphs are plotted for the maximum growth rate of instability and for wave number at marginal stability against wave steepness for different values of air flow velocity and basic current shears. Significant deviations are noticed from the results obtained from the third order evolution equation, which is the nonlinear Schrödinger equation.
Źródło:
International Journal of Applied Mechanics and Engineering; 2015, 20, 3; 517-530
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling ductile damage of steel in aggressive environment
Autorzy:
Kucharski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1933197.pdf
Data publikacji:
2006
Wydawca:
Politechnika Gdańska
Tematy:
stress corrosion damage
reaction-diffusion equations
damage evolution equation
FEM
Opis:
This paper is a proposition of a new damage model, extended to include the influence of the external environment, based on the Gurson yield function and a new damage evolution equation. The model also contains a mass transport equation based on Pick's law. A comparison of experimental and numerical results is included.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2006, 10, 4; 417-425
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possibilities of the numerical solution of the dislocation evolution equation for stochastic variables
Możliwości numerycznego rozwiązania równanie opisującego ewolucję dyslokacji dla zmiennych stochastycznych
Autorzy:
Milenin, Ivan
Rauch, Łukasz
Szeliga, Danuta
Pietrzyk, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/29520328.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
evolution of dislocation
stochastic variable
Monte Carlo method
zmienna stochastyczna
metoda Monte Carlo
Opis:
The model describing evolution of dislocation population based on fundamental works of Kocks, Estrin and Mecking (KEM) is a useful tool in modelling of metallic materials processing. In combination with the Sandstrom and Lagneborg approach it can predict changes of the dislocation density accounting for hardening, recovery and recrystallization. Numerical solutions of a one-parameter model (average dislocation density), as well as for two types of dislocations and three types of dislocation are described in the literature. All these solutions were performed for deterministic variables. On the other hand, an advanced modelling of materials requires often an information about distribution of parameters. This is the case when uncertainty of the model has to be evaluated or when an information about distribution of product properties is needed. The latter is crucial when deterioration of local formability is caused by sharp gradients of properties. Thus, the investigation of possibilities of numerical solution for the KEM model with stochastic variables was the main objective of the present work. Evolution equation was written for the distribution function and solution was performed using Monte Carlo method. Analysis of the results with respect to the reliability and computing costs was performed. The conclusions towards selection of the best approach were formulated.
Model opisujący ewolucję populacji dyslokacji wykorzystujący fundamentalne prace Kocksa, Estrina i Meckinga (KEM model) jest użytecznym narzędziem w modelowaniu przetwórstwa materiałów metalicznych. W połączeniu z modelem Sandstroma i Lagneborga możliwe jest przewidywanie zmian gęstości dyslokacji uwzględniając zjawiska umocnienia, zdrowienia i rekrystalizacji. Numeryczne rozwiązania dla jednoparametrowego modelu (średniej gęstości dyslokacji), jak i dla dwóch lub trzech rozdajów dyslokacji, jest opisane w literaturze. Te rozwiązania zostały przeprowadzone dla zmiennych deterministycznych. Z drugiej strony zaawansowane modelowanie materiałów wymaga informacji o rozkładzie parametrów. Ma to miejsce np., kiedy potrzebna jest ocena niepewności wyników lub informacja o funkcji rozkładu własności materiału. To ostatnie jest ważne, kiedy obniżenie lokalnej odporności mateiału na pękanie jest powodowane przez ostre gradienty własności. Stąd celem niniejszej pracy była ocena możliwości numerycznego rozwiązania dla modelu KEM ze zmiennymi losowymi. Równanie ewolucji dyslokacji zapisano dla funkcji rozkładu prawdopodobieństwa i przeprowadzono rozwiązanie wykorzystując metodę Monte Carlo. Przeprowadzono analizę wyników w aspekcie ich dokładności oraz oceniając koszty obliczeń. Sformułowane zostały wnioski sugerujące dobór najlepszych parametrów modelu numerycznego.
Źródło:
Computer Methods in Materials Science; 2019, 19, 4; 169-173
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On nonexistence of global in time solution for a mixed problem for a nonlinear evolution equation with memory generalizing the Voigt-Kelvin rheological model
Autorzy:
Pukach, P.
Il'kiv, V.
Nytrebych, Z.
Vovk, M.
Powiązania:
https://bibliotekanauki.pl/articles/255696.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
boundary value problem
beam vibrations
nonlinear evolution equation
Voigt-Kelvin model
memory
blowup
Opis:
The paper deals with investigating of the first mixed problem for a fifth-order nonlinear evolutional equation which generalizes well known equation of the vibrations theory. We obtain sufficient conditions of nonexistence of a global solution in time variable.
Źródło:
Opuscula Mathematica; 2017, 37, 5; 735-753
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of randomness on the stability of capillary gravity waves in the presence of air flowing over water
Autorzy:
Majumder, D. P.
Dhar, A. K.
Powiązania:
https://bibliotekanauki.pl/articles/265777.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
capillary gravity waves
randomness
evolution equation
instability
fala grawitacyjna
przypadkowość
niestabilność
Opis:
A nonlinear spectral transport equation for the narrow band Gaussian random surface wave trains is derived from a fourth order nonlinear evolution equation, which is a good starting point for the study of nonlinear water waves. The effect of randomness on the stability of deep water capillary gravity waves in the presence of air flowing over water is investigated. The stability is then considered for an initial homogenous wave spectrum having a simple normal form to small oblique long wave length perturbations for a range of spectral widths. An expression for the growth rate of instability is obtained; in which a higher order contribution comes from the fourth order term in the evolution equation, which is responsible for wave induced mean flow. This higher order contribution produces a decrease in the growth rate. The growth rate of instability is found to decrease with the increase of spectral width and the instability disappears if the spectral width increases beyond a certain critical value, which is not influenced by the fourth order term in the evolution equation.
Źródło:
International Journal of Applied Mechanics and Engineering; 2015, 20, 4; 835-855
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of capillarity on fourth order nonlinear evolution equation for two Stokes wave trains in deep water in the presence of air flowing over water
Autorzy:
Dhar, A. K.
Mondal, J.
Powiązania:
https://bibliotekanauki.pl/articles/265884.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
nonlinear evolution equation
surface capillary gravity wave
stability
grawitacja
fala kapilarna
równania nieliniowe
Opis:
Fourth order nonlinear evolution equations, which are a good starting point for the study of nonlinear water waves, are derived for deep water surface capillary gravity waves in the presence of second waves in which air is blowing over water. Here it is assumed that the space variation of the amplitude takes place only in a direction along which the group velocity projection of the two waves overlap. A stability analysis is made for a uniform wave train in the presence of a second wave train. Graphs are plotted for the maximum growth rate of instability wave number at marginal stability and wave number separation of fastest growing sideband component against wave steepness. Significant improvements are noticed from the results obtained from the two coupled third order nonlinear Schrödinger equations.
Źródło:
International Journal of Applied Mechanics and Engineering; 2015, 20, 2; 267-282
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fourier image methods for evolution equations of deep-water waves
Autorzy:
Jankowski, Jan
Leszczyński, Henryk
Powiązania:
https://bibliotekanauki.pl/articles/1955223.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska
Tematy:
wave evolution
Laplace equation
Fourier transform
method of lines
Gauss-Hermite quadrature
Opis:
The velocity potential of the fluid satisfies the Laplace equation with nonlocal boundary conditions on a free surface. This differential problem is transformed to an evolution equation in Fourier variables. The Fourier transform images of boundary functions are approximated by Picard's iterations and the method of lines on meshes related to roots of Hermite polynomials. Due to convolutions of sine and cosine functions the integral terms of Picard's iterations reveal unexpected instabilities for wave numbers in a neighborhood of zero.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2019, 23, 3; 261-268
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kolmogorov equation solution: multiple scattering expansion and photon statistics evolution modeling
Autorzy:
Guirao, M.
Leble, S.
Powiązania:
https://bibliotekanauki.pl/articles/1954433.pdf
Data publikacji:
2014
Wydawca:
Politechnika Gdańska
Tematy:
Kolmogorov equation
Fokker-Planck equation
multiple scattering expansion
photon statistics evolution
single scattering term
X-rays in beryl
Opis:
We consider a formulation of the Cauchy problem for the Kolmogorov equation which corresponds to a localized source of particles to be scattered by a medium with a given scattering amplitude density. The multiple scattering ampl itudes are introduced and the corresponding series solution of the equation is constructed. We investigate the integral representation for the first series terms, its estimations and values of the photon number of finite and point receivers. Application to the LIDAR problem and X-ray beam scattering for orthogonal and inclined to a layer is considered.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2014, 18, 2; 187--203
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Penna model of population evolution
Autorzy:
Magdoń-Maksymowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/1941717.pdf
Data publikacji:
2000
Wydawca:
Politechnika Gdańska
Tematy:
population evolution
biological ageining
Penna model
bad mutations
migration process
logistic equation
Gompertz law
Opis:
Computer studies of population evolution are presented. Numerical calculations are based on the Penna model. This model accounts for mutation load of individuals resulting in non-trivial age (a) dependence of the mortality rate q(a) which may be compared with empirical data. The Penna model is also very flexible for suitable modifications of the population evolution process such as hunting, genetic death, migration etc. Here we present some examples of the population growth for different evolution rules. Calculations require about 100 MB memory for 10/sup 6/ population which is necessary to get reliable statistics. The typical running time for 3000 iteration steps is several hours for a HP S2000 machine.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2000, 4, 1; 5-18
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal control of nonlinear evolution equations
Autorzy:
Papageorgiou, Nikolaos
Yannakakis, Nikolaos
Powiązania:
https://bibliotekanauki.pl/articles/729352.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
evolution triple
compact embedding
monotone operator
pseudomonotone operator
L-generalized pseudomonotonicity
integration by parts
evolution inclusion
saddle point
necessary conditions
adjoint equation
distributed parameter systems
Opis:
In this paper, first we consider parametric control systems driven by nonlinear evolution equations defined on an evolution triple of spaces. The parametres are time-varying probability measures (Young measures) defined on a compact metric space. The appropriate optimization problem is a minimax control problem, in which the system analyst minimizes the maximum cost (risk). Under general hypotheses on the data we establish the existence of optimal controls.
Then we pass to nonparametric systems, which are governed by nonlinear evolution equations with nonmonotone operators. We prove two existence results for such evolution inclusions, which are of independent interest and extend significantly the results existing in the literature. Then we solve time-optimal and Meyer-type optimization problems. In Section 5, we derive necessary conditions for saddle point optimality in the minimax control problem. We conclude the paper with three examples of distributed parameter control systems.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2001, 21, 1; 5-50
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal control of general McKean-Vlasov stochastic evolution equations on Hilbert spaces and necessary conditions of optimality
Autorzy:
Ahmed, N.
Powiązania:
https://bibliotekanauki.pl/articles/729626.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
McKean-Vlasov stochastic differential equation
Hilbert spaces
relaxed controls
existence of optimal controls
Opis:
In this paper we consider controlled McKean-Vlasov stochastic evolution equations on Hilbert spaces. We prove existence and uniqueness of solutions and regularity properties thereof. We use relaxed controls, adapted to a current of sub-sigma algebras generated by observable processes, and taking values from a Polish space. We introduce an appropriate topology based on weak star convergence. We prove continuous dependence of solutions on controls with respect to appropriate topologies. Theses results are then used to prove existence of optimal controls for Bolza problems. Then we develop the necessary conditions of optimality based on semi-martingale representation theory on Hilbert spaces. Next we show that the adjoint processes arising from the necessary conditions optimality can be constructed from the solution of certain BSDE.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2015, 35, 2; 165-195
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A general class of McKean-Vlasov stochastic evolution equations driven by Brownian motion and Lèvy process and controlled by Lèvy measure
Autorzy:
Ahmed, N.
Powiązania:
https://bibliotekanauki.pl/articles/729570.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
McKean-Vlasov stochastic differential equation
Hilbert spaces
existence of optimal controls
Opis:
In this paper we consider McKean-Vlasov stochastic evolution equations on Hilbert spaces driven by Brownian motion and L`evy process and controlled by L`evy measures. We prove existence and uniqueness of solutions and regularity properties thereof. We consider weak topology on the space of bounded Le´vy measures on infinite dimensional Hilbert space and prove continuous dependence of solutions with respect to the Le´vy measure. Then considering a certain class of Le´vy measures on infinite as well as finite dimensional Hilbert spaces, as relaxed controls, we prove existence of optimal controls for Bolza problem and some simple mass transport problems
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2016, 36, 2; 181-206
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solutions of the nonlinear evolution problems and their applications
Autorzy:
Amir, Muhammad
Haider, Jamil Abbas
Rahman, Jamshaid Ul
Ashraf, Asifa
Powiązania:
https://bibliotekanauki.pl/articles/2233663.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
Laplace variational iteration method
nonlinear problems
duffing equation
simple pendulum
mass and spring oscillator
Simulink
Opis:
In this article, a well-known technique, the variational iterative method with the Laplace transform, is used to solve nonlinear evolution problems of a simple pendulum and mass spring oscillator, which represents the duffing equation. In the variational iteration method (VIM), finding the Lagrange multiplier is an important step, and the variational theory is often used for this purpose. This paper shows how the Laplace transform can be used to find the multiplier in a simpler way. This method gives an easy approach for scientists and engineers who deal with a wide range of nonlinear problems. Duffing equation is solved by different analytic methods, but we tackle this for the first time to solve the duffing equation and the nonlinear oscillator by using the Laplace-based VIM. In the majority of cases, Laplace variational iteration method (LVIM) just needs one iteration to attain high accuracy of the answer for linearization anddiscretization, or intensive computational work is needed. The convergence criteria of this method are efficient as compared with the VIM. Comparing the analytical VIM by Laplace transform with MATLAB’s built-in command Simulink that confirms the method’s suitability for solving nonlinear evolution problems will be helpful. In future, we will be able to find the solution of highly nonlinear oscillators.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 3; 357--363
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The identification of the boundary geometry with corner points in inverse two-dimensional potential problems
Autorzy:
Zieniuk, E.
Gabrel, W.
Powiązania:
https://bibliotekanauki.pl/articles/1931586.pdf
Data publikacji:
2002
Wydawca:
Politechnika Gdańska
Tematy:
inverse boundary value problem
boundary geometry identification
geometry
parametric integral equation system
finite element method
boundary element method
evolution algorithm
genetic algorithms
Opis:
The paper presents fragment of a larger study concerning the effective methods of solving the inverse boundary value problems. The boundary value problem described here is formulated as a problem of the identification of a boundary geometry with corner points. A method using a parametric integral equations system (PIES) is proposed. PIES used in the method makes the easy modelling of the geometry with corner points possible. This effect is obtained by the application of modified splines. An evolution algorithm is used for the effective control of modifications of the boundary geometry. Some experimental tests of the efficiency of the discussed method were performed for two-dimensional inverse potential problems.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2002, 6, 4; 651-660
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Group invariant solution of some time fractional evolution equations
Autorzy:
Mandal, H.
Bira, B.
Powiązania:
https://bibliotekanauki.pl/articles/122890.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
fractional coupled Burger’s equation
fractional DSSH equations
Riemann Liouville’s fractional derivative
Erdélyi-Kober operator
symmetry analysis
exact solution
równania ewolucji
ułamkowe równania różniczkowe
ułamkowe równania DSSH
pochodna ułamkowa Riemanna Liouville'a
operator Erdélyi-Kober
Opis:
In this paper, we consider some classes of a system of nonlinear fractional differential equations (FDEs) arising in some important physical phenomena. Using symmetry group of transformations, the given systems of fractional partial differential equations (FPDEs) are reduced to systems of fractional ordinary differential equations (FODEs). Further, using the group invariant condition, we solve the reduced systems of FODEs and exact solutions of the given equations are constructed. Finally, the physical significance of the solutions are investigated graphically based on the exact solutions in order to highlight the importance of the study.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2018, 17, 4; 35-46
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 26

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies