Search results for " analisi"
showing 10 items of 1252 documents
A note on boundary conditions for nonlinear operators
2008
We investigate boundary conditions for strict-$\psi$-contractive and $\psi$-condensing operators. We derive results on the existence of eigenvectors with positive and negative eigenvalues and we obtain fixed point theorems for classes of noncompact opera\-tors.
Absolutely continuous variational measures of Mawhin's type
2011
Abstract In this paper we study absolutely continuous and σ-finite variational measures corresponding to Mawhin, F- and BV -integrals. We obtain characterization of these σ-finite variational measures similar to those obtained in the case of standard variational measures. We also give a new proof of the Radon-Nikodým theorem for these measures.
I Telamoni del Tempio di Zeus ad Agrigento: rilievi, disegni e ricostruzioni
2013
Oggetto dello studio qui presentato è la ricostruzione di un intercolumnio del fronte esterno del Tempio di Zeus ad Agrigento, basata sul rilievo del Telamone oggi custodito presso il Museo Archeologico, sugli studi e i numerosi saggi di ricostruzione proposti dagli studiosi dal XVIII secolo fino alla metà dello scorso secolo e sulla analisi strutturale del Telamone ricostruito nel Museo. The drawings of the telamones, the giant statues placed the front of the Temple of Zeus in the archaeological area of Agrigento, have fascinated some of the most famous neoclassical architects in Europe. The virtual reconstruction of one intercolumnial of the Temple, based both on the range-based survey of…
Aushandeln von Rederechten im Unterricht Eine multimodale Vergleichsstudie zur fremdsprachlichen Unterrichtsinteraktion in Italien und Deutschland
2017
Il testo presento un’analisi multimodale di alcune sequenze video registrate in due classe nella scuola superiore, una in Germania, l’altra in Italia. L’obbiettivo è di rendere evidente le strutture intrinseche del turn taking e turn construction e di indurre a una riflessione in ambito della formazione degli insegnanti di lingua straniera.
A sharp lower bound for some neumann eigenvalues of the hermite operator
2013
This paper deals with the Neumann eigenvalue problem for the Hermite operator defined in a convex, possibly unbounded, planar domain $\Omega$, having one axis of symmetry passing through the origin. We prove a sharp lower bound for the first eigenvalue $\mu_1^{odd}(\Omega)$ with an associated eigenfunction odd with respect to the axis of symmetry. Such an estimate involves the first eigenvalue of the corresponding one-dimensional problem. As an immediate consequence, in the class of domains for which $\mu_1(\Omega)=\mu_1^{odd}(\Omega)$, we get an explicit lower bound for the difference between $\mu(\Omega)$ and the first Neumann eigenvalue of any strip.
Computational issues of an electromagnetics transient meshless method
2019
In this paper we refer to the computational issues in solving Maxwell’ s curl equations without using any connectivity among the points in which the problem domain is discretized. The adopted procedure is able to approximate the electric and magnetic vector fields making use of the derivatives of a kernel function at points arranged in the computational domain. In order to improve the numerical accuracy, dealing with irregular data distribution or data located near the boundary, a suitable strategy is considered. The computational core of the overall process requires elementary linear algebra operations. In the paper the method is presented and the discussion is revolved to the computationa…
Semi-compatible and reciprocally continuous maps in weak non-Archimedean Menger PM-spaces
2012
In this paper, we introduce semi-compatible maps and reciprocally continuous maps in weak non-Archimedean PM-spaces and establish a common fixed point theorem for such maps. Moreover, we show that, in the context of reciprocal continuity, the notions of compatibility and semi-compatibility of maps become equivalent. Our result generalizes several fixed point theorems in the sense that all maps involved in the theorem can be discontinuous even at the common fixed point.
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.
Operators on Partial Inner Product Spaces: Towards a Spectral Analysis
2014
Given a LHS (Lattice of Hilbert spaces) $V_J$ and a symmetric operator $A$ in $V_J$, in the sense of partial inner product spaces, we define a generalized resolvent for $A$ and study the corresponding spectral properties. In particular, we examine, with help of the KLMN theorem, the question of generalized eigenvalues associated to points of the continuous (Hilbertian) spectrum. We give some examples, including so-called frame multipliers.
On Ekeland's variational principle in partial metric spaces
2015
In this paper, lower semi-continuous functions are used to extend Ekeland's variational principle to the class of parti al metric spaces. As consequences of our results, we obtain some fixed p oint theorems of Caristi and Clarke types.