All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 112 Next

Displaying 2221 – 2240 of 2633

Showing per page

Una teoria di piastra laminata piezoelettrica

Paolo Bisegna (1997)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

È presentato un modello di piastra laminata piezoelettrica, dedotto razionalmente dalla teoria tridimensionale della piezoelettricità di Voigt. Si tratta di un'estensione ai laminati piezoelettrici della teoria di laminato elastico detta «alla Reissner-Mindlin». Le equazioni che governano il problema del laminato piezoelettrico sono fornite sia in forma differenziale che in forma variazionale. Il modello proposto è utilizzato nell'analisi di alcuni semplici problemi, allo scopo di saggiarne l'affidabilità....

Uncertain input data problems and the worst scenario method

Ivan Hlaváček (2007)

Applications of Mathematics

An introduction to the worst scenario method is given. We start with an example and a general abstract scheme. An analysis of the method both on the continuous and approximate levels is discussed. We show a possible incorporation of the method into the fuzzy set theory. Finally, we present a survey of applications published during the last decade.

Unconditionally stable mid-point time integration in elastic-plastic dynamics

Alberto Corigliano, Umberto Perego (1990)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

The dynamic analysis of elastoplastic systems discretized by finite elements is dealt with. The material behaviour is described by a rather general internal variable model. The unknown fields are modelled in terms of suitable variables, generalized in Prager's sense. Time integrations are carried out by means of a generalized mid-point rule. The resulting nonlinear equations expressing dynamic equilibrium of the finite step problem are solved by means of a Newton-Raphson iterative scheme. The unconditional...

Une méthode intégrale de frontière. Application au Laplacien et à l'élasticité.

Marie-Thérèse Lacroix (1991)

Revista Matemática de la Universidad Complutense de Madrid

The aim of the paper is to give a method to solve boundary value problems associated to the Helmholtz equation and to the operator of elasticity. We transform these problems in problems on the boundary Gamma of an open set of R3. After introducing a symplectic form on H1,2(G) x H-1,2(G) we obtain the adjoint of the boundary operator employed. Then the boundary problem has a solution if and only if the boundary conditions are orthogonal, for this bilinear form, to the elements of the kernel, in a...

Unicité et contrôle pour le système de Lamé

Mourad Bellassoued (2001)

ESAIM: Control, Optimisation and Calculus of Variations

Dans cet article on étudie le problème de l’unicité locale pour le système de Lamé. On prouve qu’on a l’unicité de Cauchy par rapport à toute surface non caractéristique. Nous donnons également deux résultats de densité qui s’applique à la théorie du contrôle pour le système de Lamé.

Unicité et contrôle pour le système de Lamé

Mourad Bellassoued (2010)

ESAIM: Control, Optimisation and Calculus of Variations

In this paper, we study the uniqueness problem for the Lamé system. We prove that we have the uniqueness property across any non characteristic surface. We also give two results which apply to the boundary controllability for the Lamé system.

Uniform a priori estimates for discrete solution of nonlinear tensor diffusion equation in image processing

Olga Drblíková (2007)

Kybernetika

This paper concerns with the finite volume scheme for nonlinear tensor diffusion in image processing. First we provide some basic information on this type of diffusion including a construction of its diffusion tensor. Then we derive a semi-implicit scheme with the help of so-called diamond-cell method (see [Coirier1] and [Coirier2]). Further, we prove existence and uniqueness of a discrete solution given by our scheme. The proof is based on a gradient bound in the tangential direction by a gradient...

Currently displaying 2221 – 2240 of 2633