Search results for "ANALISI"

On the existence and multiplicity of solutions for Dirichlet's problem for fractional differential equations

2016

In this paper, by using variational methods and critical point theorems, we prove the existence and multiplicity of solutions for boundary value problem for fractional order differential equations where Riemann-Liouville fractional derivatives and Caputo fractional derivatives are used. Our results extend the second order boundary value problem to the non integer case. Moreover, some conditions to determinate nonnegative solutions are presented and examples are given to illustrate our results.

Fixed point theorems for multivalued maps via new auxiliary function

2016

We introduce a contractive condition involving new auxiliary function and prove a fixed point theorem for closed multivalued maps on complete metric spaces. An example and an application to integral equation are given in support of our findings.

Fixed point theorems on ordered metric spaces and applications to nonlinear elastic beam equations

2012

In this paper, we establish certain fixed point theorems in metric spaces with a partial ordering. Presented theorems extend and generalize several existing results in the literature. As application, we use the fixed point theorems obtained in this paper to study existence and uniqueness of solutions for fourth-order two-point boundary value problems for elastic beam equations.

On the stability of the Serrin problem

2008

We investigate stability issues concerning the radial symmetry of solutions to Serrin's overdetermined problems. In particular, we show that, if $u$ is a solution to $\Delta u=n$ in a smooth domain $\Omega \subset \rn$, $u=0$ on $\partial\Omega$ and $|Du|$ is close to 1 on $\partial\Omega$, then $\Omega$ is close to the union of a certain number of disjoint unitary balls.

Local behaviour of singular solutions for nonlinear elliptic equations in divergence form

2012

We consider the following class of nonlinear elliptic equations $$\begin{array}{ll}{-}{\rm div}(\mathcal{A}(|x|)\nabla u) +u^q=0\quad {\rm in}\; B_1(0)\setminus\{0\}, \end{array}$$ where q > 1 and $${\mathcal{A}}$$ is a positive C 1(0,1] function which is regularly varying at zero with index $${\vartheta}$$ in (2−N,2). We prove that all isolated singularities at zero for the positive solutions are removable if and only if $${\Phi\not\in L^q(B_1(0))}$$ , where $${\Phi}$$ denotes the fundamental solution of $${-{\rm div}(\mathcal{A}(|x|)\nabla u)=\delta_0}$$ in $${\mathcal D'(B_1(0))}$$ and δ0 is the Dirac mass at 0. Moreover, we give a complete classification of the behaviour near zero of al…

Mündliche Kompetenz und Bewusstsein beim unterrichtlichen Fremdsprachenlernen

2014

Das Buch befasst sich mit dem Zusammenspiel von kognitiven, emotionalen und motivationalen Faktoren beim Aufbau von mündlicher Kompetenz in Deutsch als Tertiärsprache bei erwachsenen Italienern. Es stützt sich dabei auf ein interdisziplinäres Vorgehen, das theoretisch erörtert und in seiner Methodenwahl ausführlich dargelegt wird, insbesondere die Videografie sowie intro-/retrospektive Verfahren. Die Ergebnisse der Studie veranschaulichen die Lernprozesse einmal klassenübergreifend, zum anderen erfolgt eine detaillierte Analyse der einzelnen Lernenden. Das Literaturverzeichnis liefert Lehrenden, Studierenden und Forschern eine erschöpfende bibliographische Quelle zu den behandelten Themen.

Palermo. Uno scavo d’emergenza nell’area di Piazza Marina

2012

Francesco La Grassa. Disegno e Architettura

2022

Francesco La Grassa fu un architetto e ingegnere siciliano che operò nella prima parte del Novecento tra la Sicilia e Roma: protagonista, sebbene ‘minore’, di una florida stagione architettonica segnata dalla collaborazione con una committenza colta e illuminata, fu uno degli allievi più fedeli di Ernesto Basile. Questo studio non ha interessato l'intera opera del progettista, ma soltanto le architetture non realizzate e quelle scomparse in seguito ad atti di demolizione. Tale selezione di progetti è stata analizzata attraverso un metodo d'indagine basato sull'applicazione degli strumenti della Scienza della Rappresentazione, quali Disegno, Rilievo, Analisi grafica, Modellazione tridimensio…

A Dirichlet problem for the Laplace operator in a domain with a small hole close to the boundary

2016

We study the Dirichlet problem in a domain with a small hole close to the boundary. To do so, for each pair $\boldsymbol\varepsilon = (\varepsilon_1, \varepsilon_2 )$ of positive parameters, we consider a perforated domain $\Omega_{\boldsymbol\varepsilon}$ obtained by making a small hole of size $\varepsilon_1 \varepsilon_2 $ in an open regular subset $\Omega$ of $\mathbb{R}^n$ at distance $\varepsilon_1$ from the boundary $\partial\Omega$. As $\varepsilon_1 \to 0$, the perforation shrinks to a point and, at the same time, approaches the boundary. When $\boldsymbol\varepsilon \to (0,0)$, the size of the hole shrinks at a faster rate than its approach to the boundary. We denote by $u_{\bolds…

Parametric and nonparametric A-Laplace problems: Existence of solutions and asymptotic analysis

2021

We give sufficient conditions for the existence of weak solutions to quasilinear elliptic Dirichlet problem driven by the A-Laplace operator in a bounded domain Ω. The techniques, based on a variant of the symmetric mountain pass theorem, exploit variational methods. We also provide information about the asymptotic behavior of the solutions as a suitable parameter goes to 0 + . In this case, we point out the existence of a blow-up phenomenon. The analysis developed in this paper extends and complements various qualitative and asymptotic properties for some cases described by homogeneous differential operators.