MACH2023

Dall'11 al 15 settembre 2023 si terrà a Roma, presso l'INdAM, a P.le Aldo Moro 5, Roma, il workshop MACH2023 - Mathematical modeling and Analysis of degradation and restoration in Cultural Heritage.

Il convegno riguarderà le tecniche di modellazione matematica e di simulazione per il miglioramento delle attuali strategie di conservazione e restauro del patrimonio culturale.

Commissione scientifica e organizzativa:

Gabriella Bretti (IAC - CNR, Roma)

VERBALE 2/2023

1. Comunicazioni del Direttore

2. Aggiornamenti sull'avanzamento dei progetti PNRR

3. Iniziative di divulgazione

4. Situazione logistica della sede di Bari

5. Aggiornamenti relativi alle GORU

6.Aggiornamenti sulla giornata IAC di dicembre

7. Varie ed eventuali

Screw dislocations in periodic media: Variational coarse graining of the discrete elastic energy

We study the asymptotic behavior, as the lattice spacing ? tends to zero, of the discrete elastic energy induced by topological singularities in an inhomogeneous ? periodic medium within a two-dimensional model for screw dislocations in the square lattice. We focus on the |log?| regime which, as ?->0 allows the emergence of a finite number of limiting topological singularities.

A multi-GPU aggregation-based AMG preconditioner for iterative linear solvers

We present and release in open source format a sparse linear solver which efficiently exploits heterogeneous parallel computers. The solver can be easily integrated into scientific applications that need to solve large and sparse linear systems on modern parallel computers made of hybrid nodes hosting Nvidia Graphics Processing Unit (GPU) accelerators.

Rational QZ Steps with perfect shifts

In this paper we analyze the stability of the problem of performing a rational QZ$step with a shift that is an eigenvalue of a given regular pencil H-lambda K in unreduced Hessenberg-Hessenberg form. In exact arithmetic, the backward rational QZ step moves the eigenvalue to the top of the pencil, while the rest of the pencil is maintained in Hessenberg-Hessenberg form, which then yields a deflation of the given shift. But in finite-precision the rational QZ step gets ``blurred'' and precludes the deflation of the given shift at the top of the pencil.

Coarse-Graining of a Discrete Model for Edge Dislocations in the Regular Triangular Lattice

We consider a discrete model of planar elasticity where the particles, in the reference configuration, sit on a regular triangular lattice and interact through nearest-neighbor pairwise potentials, with bonds modeled as linearized elastic springs. Within this framework, we introduce plastic slip fields, whose discrete circulation around each tri-angle detects the possible presence of an edge dislocation.

A renewal equation approach to behavioural epidemic models: analytical and numerical issues

Epidemic models structured by the age of infection can be formulated in terms of a system of renewal equations and represent a very general mathematical framework for the analysis of infectious diseases ([1, 2]). Here, we propose a formulation of renawal equations that takes into account of the behavioral response of individuals to infection. We use the so called "information index", which is a distributed delay that summarizes the information available on current and past disease trend, and extend some results regarding compartmental behavioral models [3, 4, 5].

The variational approach to s-fractional heat flows and the limit cases s-+0+and s-+1-

This paper deals with the limit cases for s-fractional heat flows in a cylindrical domain, with homogeneous Dirichlet boundary conditions, as s-+ 0+ and s-+ 1-. We describe the fractional heat flows as minimizing move-ments of the corresponding Gagliardo seminorms, with re-spect to the L2 metric. To this end, we first provide a Gamma-convergence analysis for the s-Gagliardo seminorms as s-+ 0+ and s-+ 1-; then, we exploit an abstract stability result for minimizing movements in Hilbert spaces, with respect to a sequence of Gamma-converging uniformly lambda-convex energy function-als.

A Preliminary Investigation of a Single Shock Impact on Italian Mortality Rates Using STMF Data: A Case Study of COVID-19

Mortality shocks, such as pandemics, threaten the consolidated longevity improvements, confirmed in the last decades for the majority of western countries. Indeed, just before the COVID-19 pandemic, mortality was falling for all ages, with a different behavior according to different ages and countries. It is indubitable that the changes in the population longevity induced by shock events, even transitory ones, affecting demographic projections, have financial implications in public spending as well as in pension plans and life insurance.