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 "finite" wg kryterium: Temat

  Lista filtrów

Dostawca treści

Wyrównaj
Wyświetlanie 1-15 z 1892
Tytuł:
Alternating direction Galerkin method for quasilinear parabolic equations
Autorzy:
Dryja, M.
Powiązania:
https://bibliotekanauki.pl/articles/748658.pdf
Data publikacji:
1979
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Finite elements, Rayleigh-Ritz and Galerkin methods, finite methods
Opis:
MR0549983
Consider the following parabolic equation: (1) ∂u/∂t−∑2i=1(d/dxi)ai(x,t,u,D1u,D2u)+a0(x,t,u,D1u,D2u)=f(x,t), x=(x1,x2)∈Ω⊂R2, t∈[0,T], with the initial value condition u(x,0)=u0(x), x∈Ω, and with the boundary value condition u(x,t)=0, x∈∂Ω, t∈[0,T]. For the solution of equation (1) the author proposes a variational-difference method. Namely, he approximates equation (1) by Galerkin's method with respect to the variables x1,x2 and by the finite-difference method with respect to the variable t. Under some assumptions concerning the coefficients ai, i=0,1,2, an estimate of the error is given.
Źródło:
Mathematica Applicanda; 1979, 7, 15
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Superconvergence in the finite element method
Autorzy:
Leyk, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/748740.pdf
Data publikacji:
1982
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Finite elements, Rayleigh-Ritz and Galerkin methods, finite methods
Opis:
MR0707821
For some variants of the finite element method there exist points having a remainder value or a derivation remainder remarkably less than those given by global norms. This phenomenon is called superconvergence and the points are called superconvergence points. The generalized problem corresponding to (1) is as follows: Let Hk(Ω) be Sobolev space and Hk0(Ω) the completion of the space C∞0(Ω) with norm ∥⋅∥k,Ω. Find u∈H10(Ω) such that for each v∈H10(Ω), (2) a(u,v)=(f,v)0 holds, where a(u,v)=∫Ω(∑n|α|=0aα(x)DαuDαv)dx, (f,v)0=∫Ωf(x)v(x)dx, Dα=Dα11⋯Dαnn,1.5pt Dαiiu=∂αiu/∂xαii, i=1,n¯¯¯¯¯¯¯¯. The approximate problem of the finite element variant considered is the following: Find uh∈Vh such that (3) for all v∈Vh, a(uh,v)=(f,v)0. The main result is the theorem: Let ai∈C(Ω¯), D1ai,D2ai∈L∞(Ω),i=1,2,∥σ∥∞L(Ω)≤σ,f∈L2(Ω). Suppose the eigenvalues of the operator L are different from zero, and u∈H4(Ω)∩H10(Ω). Then there exists h0 such that for h≤h0, h2∑P∈G|grad(u−uh)(P)|≤Ch3(|u|3+|u|4), where u and uh are the solutions of problems (2) and (3), respectively, and C is some constant independent of h. Further, |u|k={∫Ω(∑|α|=k(Dαu)2)dx}1/2, G=⋃N1N2i=1Fi(R), R={(±3√/3,±3√/3)} is a Gauss point set in the quadrant S={(ξ1,ξ2):|ξk|≤1,k=1,2}, and Fi(F(1)i,F(2)i):S→ei, ei an element; F(1)i(ξ1,ξ2)=x(i)0+h1ξ1/2, F(2)i(ξ1,ξ2)=y(i)0+h2ξ2/2, and (x(i)0,y(i)0) is the middle element.
Źródło:
Mathematica Applicanda; 1982, 10, 20
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Galerkins method of variable directions for parabolic obstacle variational inequalities
Autorzy:
Zemła, Adam
Powiązania:
https://bibliotekanauki.pl/articles/747741.pdf
Data publikacji:
1983
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Methods of Newton-Raphson, Galerkin and Ritz types
Variational inequalities
Finite elements, Rayleigh-Ritz, Galerkin and collocation methods
Opis:
.
Author introduction (translated from the Polish): "This paper is an attempt to extend Galerkin's variable directions method ADG, used in the solution of differential equations [see M. Dryja , same journal 15 (1979), 5–23; MR0549983; G. Fairweather , Finite element Galerkin methods for differential equations, Chapter 6, Dekker, New York, 1978; MR0495013] to inequalities. The numerical properties of the scheme of the ADG method are discussed using the example of the following variational problem: Find a function u:(0,T)→K⊂V⊂H such that: (u′+Au−f,v−u)H≥0 for all v∈K and almost all t in [0,T), u(0)=u0, where V and H are Hilbert spaces of functions defined on Ω. The problem studied in this paper is called a parabolic obstacle variational inequality. We restrict ourselves to problems with a symmetric operator A whose coefficients do not depend on the time variable."
Źródło:
Mathematica Applicanda; 1983, 11, 23
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The projective-Newton methods
Autorzy:
Hobot, Grażyna
Pokora, Teresa
Powiązania:
https://bibliotekanauki.pl/articles/748356.pdf
Data publikacji:
1986
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Finite elements, Rayleigh-Ritz and Galerkin methods, finite methods
Single equations
Opis:
.
In this paper we consider the Newton-like methods for the solution of nonlinear equations. In each step of the Newton method the linear equations are solved approximatively by a projection method. We call this a projective-Newton method. We investigate the convergence and the order of convergence for these methods. Next, the projective-Newton methods in the finite element space are applied for nonlinear elliptic boundary value problems. In this case the linear equations of the Newton method are solved by the Ritz method.
Źródło:
Mathematica Applicanda; 1986, 14, 27
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Superconvergence effect in finite element methods for two-point boundary value problems
Autorzy:
Regińska, Teresa
Powiązania:
https://bibliotekanauki.pl/articles/747715.pdf
Data publikacji:
1987
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Boundary value problems
Finite elements, Rayleigh-Ritz, Galerkin and collocation methods
Opis:
.
Approximate methods for solving two-point boundary value problems are considered. The aim of the paper is to explain superconvergence effect in the methods using finite element spaces. The existence of a class of the methods with the superconvergence property is demonstrated. Detailed proofs of superconvergence are presented for the case of the Galerkin method (due to Douglas and Dupont results) and for some example of external method.
Źródło:
Mathematica Applicanda; 1987, 16, 30
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The finite difference approximation for the Dirichlet problem with a non-uniform mesh on a boundary
Autorzy:
Morawiec, Grażyna
Powiązania:
https://bibliotekanauki.pl/articles/747719.pdf
Data publikacji:
1987
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Derivation of finite difference approximations
Error bounds
Opis:
.
The author describes a construction of the positive difference scheme, which is the approximation of the Dirichlet problem for an elliptic second order equation with mixed derivatives in an arbitrary region in R2. The a priori estimation for the approximate solution is proved and the estimation of the rate of convergence in maximum norm is established.
Źródło:
Mathematica Applicanda; 1987, 16, 30
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
H^(-1) Galerkin-collocation method with quadratures for two point boundary value problems
Autorzy:
Leyk, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/747667.pdf
Data publikacji:
1989
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Finite elements, Rayleigh-Ritz, Galerkin and collocation
Boundary value problems
Opis:
.
In the paper, the H^(-1)Galerkin-collocation method with quadratures (instead of integrals) for two point boundary value problems is considered. Approximate solution is a piecewise polynomial of degree r. It is proved that the method is stable and the error in L2-norm is of order O(h^(r+1)) if the used quadrature is exact for polynomial of degree not greater than r+1.
Źródło:
Mathematica Applicanda; 1989, 17, 31
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Difference method for a nonlinear parabolic equation of second order in two space variables
Autorzy:
Kawecki, Roman
Powiązania:
https://bibliotekanauki.pl/articles/747916.pdf
Data publikacji:
1990
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Finite difference methods
Stability and convergence of numerical methods
Opis:
.
A.C. Reynolds in his paper (1972) proposed a difference parametric method for solving the Fourier problem for a nonlinear parabolic equation of second order in one space variable. The paper presents a generalization of Reynolds’ method for the problem in two space variables with mixed derivatives. In this paper, Fourier problems for a general class of nonlinear parabolic equation, in QT = Q x [0, T], are studied. To solve this problem we construct a finite difference scheme with a real parameter. We prove that the solutions of certain associated finite difference equations are unique and converge to the solution of the initial-boundary value problem with 0(h^2) rate of convergence.
Źródło:
Mathematica Applicanda; 1990, 18, 32
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On asymptotic expansions of global errors
Autorzy:
Pfeifer, Eckhard
Powiązania:
https://bibliotekanauki.pl/articles/747786.pdf
Data publikacji:
1990
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Finite difference methods
Opis:
.
We consider a linear partial differential equation with constant coefficients and the corresponding difference equation. Conditions are given under which the error possesses an asymptotic expansion with respect to h. These results are applied to obtain asymptotic expansions of some quadratures and of the approximate solution of a boundary value problem for a second order differential equation.
Źródło:
Mathematica Applicanda; 1990, 18, 32
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for solving the Neumann problem for the Poisson equation on the exterior of a poligon
Autorzy:
Roliński, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/747369.pdf
Data publikacji:
1993
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Boundary element methods
Finite elements, Rayleigh-Ritz and Galerkin methods, finite methods
Opis:
.
This paper is concerned with a numerical method for solving the problem Δu=f in Ωc (=intR2\Ω), (du/dn)|Γ=g, where ΩR2 is a polygon and Γ is the boundary of Ω. The method is based on coupling finite and boundary element techniques. To compensate for the loss of smoothness of the solution u near the corners of the polygon Ω we refine the triangulation without changing the number of triangles. We apply the affine triangular Lagrangean element of degree kN and the Lagrangean boundary element of degree k−1 to obtain the optimal order of convergence via the Galerkin projection.
Źródło:
Mathematica Applicanda; 1993, 22, 36
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of the exterior Neumann problem for the Poisson equation in connection with a numerical procedure
Autorzy:
Roliński, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/747373.pdf
Data publikacji:
1993
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Boundary element methods
Boundary value problems for second-order elliptic equations
Finite elements, Rayleigh-Ritz and Galerkin methods, finite methods
Opis:
.
This paper is concerned with transforming the exterior problem Δu=f on Ωc, (∂u/∂n)|Γ=g, where ΩR2 is a bounded region and Ω^(c)=int(R2\Ω), into a problem represented by two equations. The first one is posed on a bounded domain and the second one is posed on the outer part of the boundary of the domain. This new problem is suitable for a numerical method based on coupling the finite and boundary element methods.
Źródło:
Mathematica Applicanda; 1993, 22, 36
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functions of several variables of finite variation and their differentiability
Autorzy:
Idczak, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/1311656.pdf
Data publikacji:
1994
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
functions of several variables
nondecreasing functions
functions of finite variation
Fréchet differentiability
Opis:
Some differentiability properties of functions of several variables of finite variation are investigated.
Źródło:
Annales Polonici Mathematici; 1994-1995, 60, 1; 47-56
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multipliers in Sobolev spaces and exact convergence rate estimates for the finite-difference schemes
Autorzy:
Jovanović, Boško
Powiązania:
https://bibliotekanauki.pl/articles/1361062.pdf
Data publikacji:
1994
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
finite differences
multipliers
boundary-value problems
Sobolev spaces
Opis:
In this paper we present some recent results concerning convergence rate estimates for finite-difference schemes approximating boundary-value problems. Special attention is given to the problem of minimal smoothness of coefficients in partial differential equations necessary for obtaining the results.
Źródło:
Banach Center Publications; 1994, 29, 1; 165-173
0137-6934
Pojawia się w:
Banach Center Publications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bing maps and finite-dimensional maps
Autorzy:
Levin, Michael
Powiązania:
https://bibliotekanauki.pl/articles/1205475.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
finite-dimensional maps
hereditarily indecomposable continua
Opis:
Let X and Y be compacta and let f:X → Y be a k-dimensional map. In [5] Pasynkov stated that if Y is finite-dimensional then there exists a map $g : X → \mathbb{I}^k$ such that dim (f × g) = 0. The problem that we deal with in this note is whether or not the restriction on the dimension of Y in the Pasynkov theorem can be omitted. This problem is still open.
 Without assuming that Y is finite-dimensional Sternfeld [6] proved that there exists a map $g : X → \mathbb{I}^k$ such that dim (f × g) = 1. We improve this result of Sternfeld showing that there exists a map $g : X → mathbb{I}^{k+1}$ such that dim (f × g) =0. The last result is generalized to maps f with weakly infinite-dimensional fibers.
 Our proofs are based on so-called Bing maps. A compactum is said to be a Bing compactum if its compact connected subsets are all hereditarily indecomposable, and a map is said to be a Bing map if all its fibers are Bing compacta. Bing maps on finite-dimensional compacta were constructed by Brown [2]. We construct Bing maps for arbitrary compacta. Namely, we prove that for a compactum X the set of all Bing maps from X to $\mathbb{I}$ is a dense $G_δ$-subset of $C(X, \mathbb{I})$.
Źródło:
Fundamenta Mathematicae; 1996, 151, 1; 47-52
0016-2736
Pojawia się w:
Fundamenta Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wavelet transform for time-frequency representation and filtration of discrete signals
Autorzy:
Popiński, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/1340246.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
spectro-temporal filtration
orthonormal wavelet base
Discrete Fourier Transform
finite duration signals
Opis:
A method to analyse and filter real-valued discrete signals of finite duration s(n), n=0,1,...,N-1, where $N=2^p$, p>0, by means of time-frequency representation is presented. This is achieved by defining an invertible discrete transform representing a signal either in the time or in the time-frequency domain, which is based on decomposition of a signal with respect to a system of basic orthonormal discrete wavelet functions. Such discrete wavelet functions are defined using the Meyer generating wavelet spectrum and the classical discrete Fourier transform between the time and the frequency domains.
Źródło:
Applicationes Mathematicae; 1995-1996, 23, 4; 433-448
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 1892

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