Informacja

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

Wyszukujesz frazę "newton" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
A conjugate gradient method with quasi-Newton approximation
Autorzy:
Koko, Jonas
Powiązania:
https://bibliotekanauki.pl/articles/1208176.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Newton and quasi-Newton methods
unconstrained high-dimensional optimization
conjugate gradient methods
Opis:
The conjugate gradient method of Liu and Storey is an efficient minimization algorithm which uses second derivatives information, without saving matrices, by finite difference approximation. It is shown that the finite difference scheme can be removed by using a quasi-Newton approximation for computing a search direction, without loss of convergence. A conjugate gradient method based on BFGS approximation is proposed and compared with existing methods of the same class.
Źródło:
Applicationes Mathematicae; 2000, 27, 2; 153-165
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of rounding errors on a certain class of iterative methods
Autorzy:
Argyros, Ioannis
Powiązania:
https://bibliotekanauki.pl/articles/1208172.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Fréchet derivative
Lipschitz conditions
Newton-like method
inexact Newton-like method
Banach space
Opis:
In this study we are concerned with the problem of approximating a solution of a nonlinear equation in Banach space using Newton-like methods. Due to rounding errors the sequence of iterates generated on a computer differs from the sequence produced in theory. Using Lipschitz-type hypotheses on the mth Fréchet derivative (m ≥ 2 an integer) instead of the first one, we provide sufficient convergence conditions for the inexact Newton-like method that is actually generated on the computer. Moreover, we show that the ratio of convergence improves under our conditions. Furthermore, we provide a wider choice of initial guesses than before. Finally, a numerical example is provided to show that our results compare favorably with earlier ones.
Źródło:
Applicationes Mathematicae; 2000, 27, 3; 369-375
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Łojasiewicz exponent of the gradient of a polynomial function
Autorzy:
Lenarcik, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1294050.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
polynomial mapping
Łojasiewicz exponent
Newton diagram
Opis:
Let $h = ∑ h_{αβ} X^αY^β$ be a polynomial with complex coefficients. The Łojasiewicz exponent of the gradient of h at infinity is the least upper bound of the set of all real λ such that $|grad h(x,y)| ≥ c|(x,y)|^λ$ in a neighbourhood of infinity in ℂ², for c > 0. We estimate this quantity in terms of the Newton diagram of h. Equality is obtained in the nondegenerate case.
Źródło:
Annales Polonici Mathematici; 1999, 71, 3; 211-239
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-zero constant Jacobian polynomial maps of $ℂ²$
Autorzy:
Chau, Nguyen
Powiązania:
https://bibliotekanauki.pl/articles/1294068.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Jacobian conjecture
polynomial automorphism
Newton-Puiseux expansion
Opis:
We study the behavior at infinity of non-zero constant Jacobian polynomial maps f = (P,Q) in ℂ² by analyzing the influence of the Jacobian condition on the structure of Newton-Puiseux expansions of branches at infinity of level sets of the components. One of the results obtained states that the Jacobian conjecture in ℂ² is true if the Jacobian condition ensures that the restriction of Q to the curve P = 0 has only one pole.
Źródło:
Annales Polonici Mathematici; 1999, 71, 3; 287-310
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new Kantorovich-type theorem for Newtons method
Autorzy:
Argyros, Ioannis
Powiązania:
https://bibliotekanauki.pl/articles/1338842.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Newton's method
Lipschitz-Hölder condition
Kantorovich hypothesis
Banach space
Opis:
A new Kantorovich-type convergence theorem for Newton's method is established for approximating a locally unique solution of an equation F(x)=0 defined on a Banach space. It is assumed that the operator F is twice Fréchet differentiable, and that F', F'' satisfy Lipschitz conditions. Our convergence condition differs from earlier ones and therefore it has theoretical and practical value.
Źródło:
Applicationes Mathematicae; 1999, 26, 2; 151-157
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Newton numbers and residual measures of plurisubharmonic functions
Autorzy:
Rashkovskii, Alexander
Powiązania:
https://bibliotekanauki.pl/articles/1207853.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Monge-Ampère operator
local indicator
directional Lelong number
plurisubharmonic function
Newton polyhedron
Opis:
We study the masses charged by $(dd^cu)^n$ at isolated singularity points of plurisubharmonic functions u. This is done by means of the local indicators of plurisubharmonic functions introduced in [15]. As a consequence, bounds for the masses are obtained in terms of the directional Lelong numbers of u, and the notion of the Newton number for a holomorphic mapping is extended to arbitrary plurisubharmonic functions. We also describe the local indicator of u as the logarithmic tangent to u.
Źródło:
Annales Polonici Mathematici; 2000, 75, 3; 213-231
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Local convergence of inexact Newton methods under affine invariant conditions and hypotheses on the second Fréchet derivative
Autorzy:
Argyros, Ioannis
Powiązania:
https://bibliotekanauki.pl/articles/1338691.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
superlinear
Fréchet derivative
weak convergence
inexact Newton method
strong
forcing sequence
Banach space
Opis:
We use inexact Newton iterates to approximate a solution of a nonlinear equation in a Banach space. Solving a nonlinear equation using Newton iterates at each stage is very expensive in general. That is why we consider inexact Newton methods, where the Newton equations are solved only approximately, and in some unspecified manner. In earlier works [2], [3], natural assumptions under which the forcing sequences are uniformly less than one were given based on the second Fréchet derivative of the operator involved. This approach showed that the upper error bounds on the distances involved are smaller compared with the corresponding ones using hypotheses on the first Fréchet derivative. However, the conditions on the forcing sequences were not given in affine invariant form. The advantages of using conditions given in affine invariant form were explained in [3], [10]. Here we reproduce all the results obtained in [3] but using affine invariant conditions.
Źródło:
Applicationes Mathematicae; 1999, 26, 4; 457-465
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

    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