90,250 research outputs found
On the convex components of a set in
No full textWe prove a lower bound on the number of the convex components of a compact
set with non-empty interior in for all . Our result
generalizes and improves the inequalities previously obtained in M. Carozza, F.
Giannetti, F. Leonetti and A. Passarelli di Napoli, "Convex components", in
Communications in Contemporary Mathematics, Vol. 21, No. 06, 1850036 (2019) and
in M. La Civita and F. Leonetti, "Convex components of a set and the measure of
its boundary", Atti. Sem. Mat. Fis. Univ. Modena Reggio Emilia 56 (2008-2009)
71-78.Comment: 16 pages, 6 figure
ON THE LIPSCHITZ REGULARITY FOR MINIMA OF FUNCTIONALS DEPENDING ON x, u, AND ∇u UNDER THE BOUNDED SLOPE CONDITION
No full textWe prove the existence of a global Lipschitz minimizer of functionals of the form
I (u) =
\int
\Omega f(\nabla u(x)) + g(x, u(x)) dx, u \in \phi + W1,1
0 (\Omega ), assuming that \phi satisfies the bounded slope
condition (BSC). Our assumptions on the Lagrangian allow the function f to be strongly degenerate
Structural sensitivity of the finite-amplitude vortex shedding behind bluff bodies
No full textInthispaperwestudythestructuralsensitivityofthenonlinearperiodic oscillation arising in the wake of a circular cylinder for Re47. The sensibility of the periodic state to a spatially localised feedback from velocity to force is anal- ysed by performing a structural stability analysis of the problem. The sensitivity of the vortex shedding frequency is analysed by evaluating the adjoint eigenvectors of the Floquet transition operator. The product of the resulting neutral mode with the nonlinear periodic state is then used to localise the instability core. The results ob- tained with this new approach are then compared with those derived by Giannetti & Luchini [8]. An excellent agreement is found comparing the present results with the experimental data of Strykowski & Sreenivasan
WKBJ analysis in the periodic wake of a cylinder
No full textAbstractThe nature of the three-dimensional transition arising in the flow past a cylinder is investigated by applying the Lifschitz–Hameiri theory along special Lagrangian trajectories existing in its wake. Results show that the von Kármán street is unstable with regard to short-wavelength perturbations. The asymptotic analysis predicts the possible existence of both synchronous (as modes A and B) and asynchronous (as mode C) instabilities, each associated to specific Lagrangian orbits. The proposed study provides useful qualitative information on the origin of the different modes but no quantitative agreement between the growth rates predicted by the asymptotic analysis and by a global stability analysis is observed. The reasons for such mismatch are briefly discussed and possible improvements to the present analysis are suggested
Structural sensitivity of the finite-amplitude vortex shedding behind a circular cylinder
No full textIn this paper we study the structural sensitivity of the nonlinear periodic oscillation arising in the wake of a circular cylinder for Re47. The sensibility of the periodic state to a spatially localised feedback from velocity to force is analysed by performing a structural stability analysis of the problem. The sensitivity of the vortex shedding frequency is analysed by evaluating the adjoint eigenvectors of the Floquet transition operator. The product of the resulting neutral mode with the nonlinear periodic state is then used to localise the instability core. The results obtained with this new approach are then compared with those derived by Giannetti & Luchini [8]. An excellent agreement is found comparing the present results with the experimental data of Strykowski & Sreenivasan [7]. © 2009 Springer Science+Business Media B.V
Libro dei Sette Savi di Roma, versione in prosa F
No full textLa versione italiana F del Libro dei Sette Savi di Roma, qui per la prima volta in veste critica, è trasmessa da soli due testimoni, entrambi della metà del '400, il ms. Laur. Gaddi-Reliq. 166, conservato alla Biblioteca Laurenziana di Firenze, e il ms. Palatino 680, della Biblioteca Nazionale di Firenze. Il testo è un volgarizzamento in prosa dal francese, riconducibile all'ambiente mercantesco fiorentino della metà del XV secolo
Partial differential equations - W2,2-solvability of the Dirichlet probeem for a class of elliptic equations with discontinuous coefficients, by FLAVIA GIANNETTI and GIOCONDA MOSCARIELLO, communicated on April 20, 2018
No full textWe study the Dirichlet problem for the second order elliptic equation (Equation presented) in a bounded regular domain Ω ⊂ RN, N > 2. We assume that f ∈ L2 and that the coefficients aij are measurable and bounded functions with the first derivatives in the Marcinkiewicz class weak-LN and having a sufficiently small distance to L∞. Under these assumptions we prove the solvability of the problem in W2,2 ∩ W1,2∗ 0, where 2∗ =2N/N-2. An higher integrability result for the gradient of the solution is achieved when f∈LP,p>2. © 2018 European Mathematical Society Publishing House. All rights reserved
Per una edizione critica della versione italiana F del Libro dei Sette Savi di Roma
No full textLa versione italiana in prosa F del Libro dei Sette Savi di Roma, è un volgarizzamento dal francese, trasmesso da due testimoni, entrambi del '400: Laur. Gaddi-Reliq. 166 e Palatino 680 (cc. 1-77v) .
La lingua della versione F del Libro dei Sette Savi di Roma è formata dalla consueta mescidanza di tratti propriamente fiorentini, in netta prevalenza, con quelli riconducibili ad altre varietà toscane, quale frutto della sedimentazione pluridialettale avvenuta nel corso della trasmissione testuale, così come normalmente si trova nei volgarizzamenti toscani dei primi secoli della nostra lingua. Una ricognizione, sul piano paleografico, codicologico e un confronto approfondito delle lezioni dei due codici, rendono evidente la dipendenza diretta di P da G. Su Gaddi 166 dovrà dunque fondarsi un'edizione critica del testo
Contabilità analitica e analisi dei costi
No full textNel capitolo si esaminano le principali classificazioni dei costi, il modello costi-volumi-risultati, il direct costing ed il full costing a base unica e multipl
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