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Direttore Vicario: Prof. Gabriele Grillo
Responsabile Gestionale: Dr.ssa Franca Di Censo

 Seminari

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Prossimi Seminari

  • Nonintrusive reduced order models using physics informed neural networks
    Jan S. Hesthaven, Chair of Computational Mathematics and Simulation Science, EPFL, Lausanne, CH
    giovedì 29 ottobre 2020 alle ore 14:00 precise, Online seminar: https://mox.polimi.it/elenco-seminari/?id_evento=1979&t=763724

Seminari Passati

  • Onde solitarie e campi elettromagnetici
    Donato Fortunato, Università di Bari
    mercoledì 19 maggio 2004 alle ore 11:30, Dipartimento di Matematica e Applicazioni - Università degli Studi di Milano Bicocca - Via Bicocca degli Arcimboldi, 8 - Aula Dottorato
  • Approximation of multi-scale elliptic problems using patches of finite elements
    Joel Wagner, iacs-epfl
    lunedì 17 maggio 2004 alle ore 14:30, Aula Seminari MOX-6° piano dip di matematica
    ABSTRACT
    The objective of this seminar is to present a new method to solve numerically
    elliptic problems such that a better precision on the solution is needed
    in certain regions of the domain wherein the equations
    are to be solved (C.R.Acad.Sci.Paris, Ser.I 337 (2003) 679--684).
    The approximation of this type of problems with multi-scale data can be approached using
    various methods. The technique we present uses multiple levels of not necessarily nested
    grids. It is a Schwarz type domain decomposition method with complete overlapping.
    The proposed algorithm consists in solving the problem on a domain wherein we consider
    patches of elements in the regions where we would like to obtain more accuracy.
    Thus we calculate successively corrections to the solution in the patches.
    The discretizations of the latter are not necessarily conforming.
    The method resembles the Fast Adaptive Composite grid method or possibly
    a hierarchical method with a mortar method. However it is of much more flexible use
    in comparison to the latter.

    The motivation for developing such a method is for example founded in air quality management.
    Pollution emission sources, and in particular point source plumes, give
    rise to models needing careful examination of the space-scale. Getting an accurate
    simulation on large scales is linked to a simulation in subregions around the
    pollution sources using finer grids. Such a method can straightforwardly be applied
    on boundary layer problems through the use of patches in critical regions.

    In this talk we present the algorithm and illustrate its efficiency through a model problem.
    We compare the speed of convergence on nested and non-nested, structured and unstructured grids.
    A spectral analysis of the iteration operator enables us to give a good estimate of the convergence
    rate for given grids. It also leads to a numerical method to evaluate the
    constant of the Cauchy-Buniakowski-Schwarz inequality in certain cases of approximation spaces.
    Finally we illustrate on several examples our \emph{a priori} estimate for
    the convergence in the grid-size.
  • Principi variazionali in fisica
    H. Kijowski, Warsaw Univ.
    venerdì 14 maggio 2004 alle ore 12:30, Aula B.21
  • Alcuni risultati sulla distribuzione della varianza di un processo di Dirichlet
    dott.ssa ALESSANDRA GUGLIELMI, CNR-IMATI
    giovedì 13 maggio 2004 alle ore 16:30, Aula Seminari MOX, VI piano
    ABSTRACT
    Un problema interessante in ambito bayesiano non parametrico è la determinazione della legge di funzionali di misure di probabilità aleatorie.
    In particolare, di recente sono apparsi diversi lavori sulla determinazione della legge esatta di (vettori di) medie di processi di Dirichlet. In questo seminario illustrerò, invece, alcuni risultati sulla distribuzione della varianza V di un processo di Dirichlet P.
    Anzitutto, a partire da una certa espressione dei momenti di V, mostrerò l'esistenza di un legame tra la legge della varianza e quella di una funzione della media del processo di Dirichlet P, mettendo in luce alcune delle sue conseguenze. Poi mostrerò l'esistenza di una corrispondenza tra la distribuzione della varianza e il parametro del processo, con massa totale fissata, quando detto parametro varia nella classe delle misure simmetriche.
    Nel corso del seminario, saranno discussi alcuni esempi.
    Il lavoro su cui si basa il seminario e' stato svolto in collaborazione con Ilenia Epifani (Politecnico di Milano) ed Eugenio Melilli (Universita' Bocconi, Milano).
  • Dissecting the Pythagorean proposition
    Douglas Rogers, University of Tasmania
    mercoledì 12 maggio 2004 alle ore 14:30, CNR, Milano
  • Curve e superfici in architettura e arte
    E. Reyes, Univ. di Vallodolid (Spagna)
    mercoledì 12 maggio 2004 alle ore 14:30, aula V.2
  • 3D Nonlinear Dynamic Analysis of Concrete Dams
    Victor Saouma, Univ. of Colorado, Boulder-Politecnico di Milano
    martedì 11 maggio 2004 alle ore 14:30, Aula Seminari MOX-6° piano dip. di matematica
    ABSTRACT
    Concrete dams, civil engineering largest structures, have been a fertile ground for testing innovative numerical techniques. One of the first applications of finite difference was the stability analysis of a dam, and the first civil engineering paper on the finite element method dealt with the cracking of a dam.

    Whereas the design of dams is a relatively simple task (since it is limited to its linear elastic behavior), the seismic safety investigation of a dam is a much more challenging problem. One must account for joint opening and closure, water structure, and water crack interaction, foundation and rock mass interaction, and development of secondary cracks. While such analysis were shunned in the past, they are becoming increasingly necessary because of mandatory regulations and thanks to increased computational power.

    This talk will then focus on the challenges of such a nonlinear analysis. First dynamic tests on a shaking table mounted on a centrifuge will be briefly presented. A description of the computational model and selected algorithms will be presented next. Finally, practical examples of dam analysis will be presented.

    Victor Saouma is a Professor of Civil Engineering at the University of Colorado in Boulder, and a Visiting Professor at the Dipartimento di Ingegneria Strutturale at the Politecnico di Milano (hosted by Prof. Maier). His research activity on dynamic analysis of dams has been funded for the past four years by the Tokyo Electric Power Research Institute.
  • Alla scoperta della geometria nell'architettura, nell'arte e nella natura
    E. Reyes, Univ. di Vallodolid (Spagna)
    martedì 11 maggio 2004 alle ore 15:30, Laboratorio didattico