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

 Seminari

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Prossimi Seminari

  • Dealing with unreliable computing platforms at extreme scale
    Luc Giraud, INRIA (Inria Bordeaux – Sud-Ouest)
    mercoledì 23 gennaio 2019 alle ore 14:00, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO
  • Poroelasticity: Discretizations and fast solvers based on geometric multigrid methods
    Francisco José Gaspar Lorenz, Department of Applied Mathematics -Zaragoza University – Spain
    giovedì 31 gennaio 2019 alle ore 14:00, Sala Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO
  • Application of Polyconvexity and multivariable convexity of energy potentials in nonlinear solid mechanics
    Javier Bonet, University of Greenwich
    giovedì 14 febbraio 2019 alle ore 14:00, Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO

Seminari Passati

  • Emodinamica della circolazione epatica: problemi e nuove acquisizioni
    Massimiliano Tuveri, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
    giovedì 29 novembre 2018 alle ore 11:30, aula consiglio VII piano
    ABSTRACT
    : Il fegato ha una vascolarizzazione peculiare comparata con gli altri organi. Ha infatti afferente vascolari di tipo arterioso (arteria epatica) e venoso (vena porta) che confluiscono nel sistema sinusoidale del fegato. Da qui si diparte una efferenza unica venosa rappresentata dalle vene sovraepatiche. La vascolarizzazione intraparenchimale ha una struttura complessa: si divide in due lobi distinti e autonomi ognuno dei quali presenta dei segmenti (8 in tutto) che sono perfusi indipendentemente. Questo riveste una particolare importanza dal punto di vista clinico, specialmente chirurgico, quando si tratta di rimuovere parte del fegato. La quantità di fegato necessaria per la sopravvivenza del paziente, quando per motivi oncologici debba essere asportata ampia parte del fegato, è difficile da predire. Il rischio di insufficienza epatica acuta è infatti molto alto. Il paziente inoltre sviluppa un particolare quadro emodinamico rappresentato da uno stato circolator!
    io ipercinetico con aumento della gittata cardiaca e basse pressioni periferiche, aumento delle resistenze intraparenchimali epatiche e aumento della pressione portale con sviluppo di vie collaterali portosistemiche. I meccanismi alla base della rigenerazione epatica, che permettono al restante parenchima di rimanere vitale e assicurare le funzioni vitali, sono fondamentalmente regolati dallo shear stress arterioso ma sopratutto venoso. Il severo aumento della shear stress è stato posto anche in relazione al danno sinusoidale per l’espressione patologica di sostanze vasoattive.
    Un fattore chiave appare la comprensione dell’entità e del comportamento dello shear stress nel sistema portale. Vi è come detto una correlazione diretta tra la variazione e il gradiente dello shear stress e la modificazione della microcircolazione epatica e la secrezione endoteliale di sostanze vasoattive. La modellazione del fegato e delle sue componenti emodinamiche appare quindi un fattore cruciale per comprendere il funzionamento e eventuali fattori correttivi da apportare in sede clinica. Un fegato computazionale paziente-specifico appare quindi uno strumento estremamente utile per predire le modificazioni emodinamiche e pianificare nel futuro possibili strategie terapeutiche.
  • Characterization of Attraction Domains for Generic Quantum Semigroups
    Damiano Poletti, Politecnico di Milano
    giovedì 29 novembre 2018 alle ore 14:30 precise, Aula Seminari III piano
    ABSTRACT
    In my talk I will present the topics covered during my theses work, concerning problems linked to decoherence and asymptotic evolution of Quantum Markov Semigroups. More precisely I will introduce the subclass of Generic Quantum Semigroups and show existing results characterizing their decoherence-free subalgebra and their invariant states. Eventually I will show the results we obtained regarding attraction domains of invariant states, a topic closely related to the asymptotic behaviour of any state undergoing system evolution.
  • The Quantitative Alexandrov Theorem in Space forms
    Luigi Vezzoni, Università degli Studi di Torino
    martedì 27 novembre 2018 alle ore 15:15, Aula seminari 3° piano
    ABSTRACT
    The talk focuses on a recent generalization of a classical result of Alexandrov. The celebrated Alexandrov’s Soap Bubble Theorem states that the spheres are the only closed (i.e. compact and without boundary) constant mean curvature hypersurfaces embedded in the Euclidean space. The theorem has been generalized to the hyperbolic space and to the hemisphere and to a large class of curvature operators. The main result of the talk is a quantitative version of Alexandrov’s theorem which I’ve obtained in collaboration with Giulio Ciraolo and Alberto Roncoroni by using a quantitative study of the method of the moving planes. The theorem implies a new pinching Theorem for hypersurfaces in space forms.
  • First Principles Determination of Reaction Rates
    Carlo Cavallotti, Dipartimento di Chimica, Materiali e Ingegneria Chimica, “G. Natta”, Politecnico di Milano
    martedì 27 novembre 2018 alle ore 10:30, aula Saleri VI piano
    ABSTRACT
    The central focus of chemical kinetics is the determination of the rate at which one or more molecules react to transform into new molecules through the rearrangements of chemical bonds.
    Theoretically, chemical kinetics lies at the interface between quantum and classical mechanics, with the explicit formulation of rate laws requiring an extensive use of statistical thermodynamics.
    In the last years a priori rate calculations for gas phase reactions have undergone a gradual but dramatic transformation, with current predictions often rivaling the accuracy of the best available experimental data.
    In this seminar I will talk about the current status of ab initio chemical kinetics and of the challenges that must still be met in order to transform this branch of physical chemistry from a qualitative to a quantitative predictive science. A few example of research areas were contributions are necessary are the following: 1) the efficient determination of absolute and relative minima as well as first order saddle points on multidimensional potential energy surfaces for which gradient and, if necessary, Hessian information is available; 2) the determination of the number of energy states for a collection of non harmonic quantum oscillators; 3) the determination of a large number of eigenvalues for the quantum Hamiltonian of multidimensional rotors; 4) efficient approaches for the integration of the energy and momentum resolved master equation for chemically reactive systems.
  • Geometry and epithelial repair
    Luis Almeida , Laboratoire J-L Lions, CNRS and Sorbonne University
    martedì 27 novembre 2018 alle ore 14:00, aula Saleri VI piano
    ABSTRACT
    We will present work on the mechanisms used for establishing or restoring epithelial integrity which are motivated by experimental work on development and wound healing in Zebrafish and drosophila and on gap closure in monolayers of MDCK cells or keratinocytes. These works concern mathematical modeling of the dynamics of epithelial tissues pulled by lamellipodal crawling or the contraction of actomyosin cables at the gap boundary. We are particularly interested in the influence of the wound/gap geometry on the closure mechanism.
  • BIRATIONAL EQUIVALENCE OF ALGEBRAIC VARIETIES
    Shigefumi Mori, Kyoto University Institute of Advanced Study
    lunedì 26 novembre 2018 alle ore 16:30, Aula Chisini, Diparimento di Matematica, Via C. Saldini 50
  • An overview of some mathematical and computational problems in Network Science
    Michele Benzi, Scuola Normale Superiore, Pisa
    giovedì 22 novembre 2018 alle ore 14:00,  Aula Consiglio VII Piano – Edificio 14, Dipartimento di Matematica POLITECNICO DI MILANO
    ABSTRACT
    Network Science is a rapidly growing interdisciplinary area at the intersection of mathematics, computer science, and a multitude of disciplines from the natural and life sciences to the social sciences and even the humanities. Network analysis methods are now widely used in proteomics, in the study of social networks (both human and animal), in finance, in ecology, in bibliometric studies, in archeology, and in a host of other fields. In this talk I will introduce the audience to some of the mathematical and computational problems and methods of complex networks, with an emphasis on the basic notions of centrality and communicability. More specifically, I will describe some of the problems in large-scale numerical linear algebra arising in this area, and how they differ from the corresponding problems encountered in more traditional applications of numerical analysis. The talk will be accessible to students, requiring only a modest background in linear algebra, numerical analysis and graph theory.

    Contacts: paola.antonietti@polimi.it, paolo.zunino@polimi.it
  • Working with compositional data in coordinates
    Eva Fiserova, Palacky University Olomouc, Czech Republic
    mercoledì 21 novembre 2018 alle ore 14:30, aula Saleri VI piano
    ABSTRACT
    Compositional data are multivariate observations carrying only relative information, popularly expressed in percentages, proportions, mg/kg, etc. Because of features inherent to compositional data, such as scale invariance and the relative scale, the statistical analysis of raw compositional data often leads to spurious results. Natural principles of compositional data are followed by the Aitchison geometry on a simplex, the sample space of compositional data (Aitchison, 1986; Pawlowsky-Glahn et al., 2015). However, because most standard statistical methods rely on the Euclidean geometry in real space, compositional data need to be converted to this space prior to statistical processing. In the lecture, we will present the log ratio methodology for dealing with compositional data and several types of their coordinate representations, such as orthonormal log-ratio coordinates, pivot coordinates, weighted pivot coordinates (Hron et al., 2017), or symmetric balances (!
    Kynvclova et al., 2017). Their usage will be demonstrated on examples.