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Two theorems on the Scorza Dragoni property for multifunctions

Gabriele Bonanno (1989)

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

We point out two theorems on the Scorza Dragoni property for multifunctions. As an application, in particular, we improve a Carathéodory selection theorem by A. Cellina [4], by removing a compactness assumption.

Two-scale homogenization for a model in strain gradient plasticity

Alessandro Giacomini, Alessandro Musesti (2011)

ESAIM: Control, Optimisation and Calculus of Variations

Using the tool of two-scale convergence, we provide a rigorous mathematical setting for the homogenization result obtained by Fleck and Willis [J. Mech. Phys. Solids 52 (2004) 1855–1888] concerning the effective plastic behaviour of a strain gradient composite material. Moreover, moving from deformation theory to flow theory, we prove a convergence result for the homogenization of quasistatic evolutions in the presence of isotropic linear hardening.

Two-scale homogenization for a model in strain gradient plasticity

Alessandro Giacomini, Alessandro Musesti (2011)

ESAIM: Control, Optimisation and Calculus of Variations

Using the tool of two-scale convergence, we provide a rigorous mathematical setting for the homogenization result obtained by Fleck and Willis [J. Mech. Phys. Solids52 (2004) 1855–1888] concerning the effective plastic behaviour of a strain gradient composite material. Moreover, moving from deformation theory to flow theory, we prove a convergence result for the homogenization of quasistatic evolutions in the presence of isotropic linear hardening.

Tykhonov well-posedness of a heat transfer problem with unilateral constraints

Mircea Sofonea, Domingo A. Tarzia (2022)

Applications of Mathematics

We consider an elliptic boundary value problem with unilateral constraints and subdifferential boundary conditions. The problem describes the heat transfer in a domain D d and its weak formulation is in the form of a hemivariational inequality for the temperature field, denoted by 𝒫 . We associate to Problem 𝒫 an optimal control problem, denoted by 𝒬 . Then, using appropriate Tykhonov triples, governed by a nonlinear operator G and a convex K ˜ , we provide results concerning the well-posedness of problems...

Un nuovo tipo di funzionale del calcolo delle variazioni

Ennio De Giorgi, Luigi Ambrosio (1988)

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

In questo lavoro si studia una classe di funzionali che intervengono in molti problemi di Fisica Matematica e, in particolare, nel problema di trovare le configurazioni di equilibrio di una miscela di liquidi isotropi e cristalli liquidi.

Un tipo di approssimazione «dall'interno» degli insiemi di perimetro finito

Italo Tamanini, Corrado Giacomelli (1990)

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

Viene presentato un risultato di approssimazione forte degli insiemi di perimetro finito con una successione di sottoinsiemi privi di punti di densità zero sulla frontiera.

Unique localization of unknown boundaries in a conducting medium from boundary measurements

Bruno Canuto (2002)

ESAIM: Control, Optimisation and Calculus of Variations

We consider the problem of localizing an inaccessible piece I of the boundary of a conducting medium Ω , and a cavity D contained in Ω , from boundary measurements on the accessible part A of Ω . Assuming that g ( t , σ ) is the given thermal flux for t , σ ( 0 , T ) × A , and that the corresponding output datum is the temperature u ( T 0 , σ ) measured at a given time T 0 for σ A out A , we prove that I and D are uniquely localized from knowledge of all possible pairs of input-output data ( g , u ( T 0 ) A out ) . The same result holds when a mean value of the temperature...

Unique Localization of Unknown Boundaries in a Conducting Medium from Boundary Measurements

Bruno Canuto (2010)

ESAIM: Control, Optimisation and Calculus of Variations

We consider the problem of localizing an inaccessible piece I of the boundary of a conducting medium Ω, and a cavity D contained in Ω, from boundary measurements on the accessible part A of ∂Ω. Assuming that g(t,σ) is the given thermal flux for (t,σ) ∈ (0,T) x A, and that the corresponding output datum is the temperature u(T0,σ) measured at a given time T0 for σ ∈ Aout ⊂ A, we prove that I and D are uniquely localized from knowledge of all possible pairs of input-output data ( g , u ( T 0 ) A out ) . The same result...

Upper bounds for singular perturbation problems involving gradient fields

Arkady Poliakovsky (2007)

Journal of the European Mathematical Society

We prove an upper bound for the Aviles–Giga problem, which involves the minimization of the energy E ε ( v ) = ε Ω | 2 v | 2 d x + ε 1 Ω ( 1 | v | 2 ) 2 d x over v H 2 ( Ω ) , where ε > 0 is a small parameter. Given v W 1 , ( Ω ) such that v B V and | v | = 1 a.e., we construct a family { v ε } satisfying: v ε v in W 1 , p ( Ω ) and E ε ( v ε ) 1 3 J v | + v v | 3 d N 1 as ε goes to 0.

Variational approximation for detecting point-like target problems

Gilles Aubert, Daniele Graziani (2011)

ESAIM: Control, Optimisation and Calculus of Variations

The aim of this paper is to provide a rigorous variational formulation for the detection of points in 2-d biological images. To this purpose we introduce a new functional whose minimizers give the points we want to detect. Then we define an approximating sequence of functionals for which we prove the Γ-convergence to the initial one.

Variational approximation for detecting point-like target problems*

Gilles Aubert, Daniele Graziani (2011)

ESAIM: Control, Optimisation and Calculus of Variations

The aim of this paper is to provide a rigorous variational formulation for the detection of points in 2-d biological images. To this purpose we introduce a new functional whose minimizers give the points we want to detect. Then we define an approximating sequence of functionals for which we prove the Γ-convergence to the initial one.

Currently displaying 501 – 520 of 561