12 Aprile, 2013 14:30 oclock

Functional Factor Analysis For Periodic Remote Sensing Data

Surajit Ray, University of Glasgow

Aula Seminari F. Saleri VI Piano MOX- Dipartimento di Matematica, Politecnico di Milano

abstract

abstract

We present a new approach to factor rotation for functional data. This rotation is achieved by rotating the functional principal components towards a pre-defined space of periodic functions designed to decompose the total variation into components that are nearlyperiodic and nearly-aperiodic with a pre-defined period. We show that the factor rotation can be obtained by calculation of canonical correlations between appropriate spaces which makes the methodology computationally efficient. Moreover we demonstrate that our proposed rotations provide stable and interpretable results in the presence of highly complex covariance. This work is motivated by the goal of finding interpretable sources of variability in vegetation index obtained from remote sensing instruments and we demonstrate our methodology through an application of factor rotation of this data.

contact: laura.sangalli@polimi.it

9 Aprile, 2013 11:00 oclock

Mathematical Models in biology: cell growth, remodelling and response to hyperthermia treatments

Chiara Giverso, Politecnico di Milano

Aula Seminari F. Saleri VI Piano MOX- Dipartimento di Matematica, Politecnico di Milano

abstract

abstract

Continuum Mechanics and Mixture Theory provide efficient tools to study biological relevant problems.
In particular, the mechanical description of living cellular aggregates, described as a biphasic mixture, is considered.
At first we focus on the mechanical response of a quiescent aggregate and we derive an elasto-visco-plastic model able to qualitatively reproduce the stress relaxation curve and the shape recovery phenomenon observed during biomechanical experiments of uniaxial homogeneous compression.
Then we include the growth of cells, in order to make a further step towards a more realistic representation of tumor growth and remodelling.
The interplay between the internal reorganization of the tissue and cell proliferation is exploited and the model is applied to the description of cancer-spheroid growth inside healthy tissue. The proposed model is able to map the continuum change of tissue geometry of tumor aggregates and the surrounding tissue, to consider the influence of stress and nutrient availability on tumor growth and to describe the influence of cell reorganization on the overall process.
Finally we studied the feasibility of hyperthermic treatments through the stimulation by exogenous alternate magnetic fields of a portion of tissue with nanoparticles embedded into it.
The Pennes' bioheat equation, coupled with an equation representing the evolution of blood perfusion in the tissue, is solved through finite element method to predict the temperature field increase in a biological tissue as a function of the blood perfusion and operating AMF conditions.
All parameters of the model were obtained through biological experiments performed at
the Methodist Hospital Research Institute - Department of Translational Imaging (Houston, Texas).
The predictions of the model can be used to rationally design hyperthermia treatments and identify the proper route of administration depending of the magnetic nanoparticles.

contact/reference: pasquale.ciarletta@polimi.it

9 Aprile, 2013 11:15 oclock

Sezione di Probabilità Quantistica

Circulant Quantum Markov Semigroups and Quantum Entropy Production Rate

Jorge Bolaños, Universidad Autónoma Metropolitana-Iztapalapa, México D. F.

Aula Beltrami del Dipartimento di Matematica dell Universita di Pavia

abstract

abstract

I will present a class of generators of QMS which have a close relationship with its commutative restrictions, yet quantum dynamic arises from them, and are quite easy to compute. I will give a definition of Quantum entropy production rate and show its relationship to quantum detailed balance and classical entropy production rate.

Il seminario rientra nelle attività del progetto FIRB 2010 Quantum Markov Semigroups and their empirical estimation.

8 Aprile, 2013 17:00

Seminario Matematico e Fisico di Milano

STABILITY CONDITIONS AND DYNAMICAL SYSTEMS

LUDMIL KATZARKOV, Fakultaet fuer Mathematik, Universitaet Wien

Università di Milano, Dipartimento di Matematica, Via Saldini

abstract

abstract

In this talk we will connect moduli spaces of stability conditions of categories to dynamical systems.
We will show how classical ideas from category theory and from ergodic theory unify to benefit both subjects.

27 Marzo, 2013 12:15

Seminari di Cultura Matematica

Navigazione e carte nautiche dal Medioevo all’età delle grandi scoperte geografiche

Corradino Astengo, Dipartimento di Scienze dell’Antichità, Università di Genova

Aula B.2.1 (edificio 14 - Nave ) via Bonardi 9, Milano.

In this talk we will connect moduli spaces of stability conditions of categories to dynamical systems.
We will show how classical ideas from category theory and from ergodic theory unify to benefit both subjects.

26 Marzo, 2013 11:00 oclock

Seminari di Cultura Matematica

Finite volume schemes for dispersive wave propagation and runup

Theodoros Katsaounis, University of Crete

Aula Seminari F. Saleri VI Piano MOX- Dipartimento di Matematica, Politecnico di Milano

abstract

abstract

Finite volume schemes are commonly used to construct approximate solutions to conservation laws. In this study we extend the framework
of the finite volume methods to dispersive water wave models, in particular to Boussinesq type systems. We focus mainly on the application of the method to bidirectional non- linear, dispersive wave propagation in one space dimension. Special emphasis is given to
important nonlinear phenomena such as solitary waves interactions,dispersive shock wave formation and the runup of breaking and
non-breaking long waves.

20 Marzo, 2013 12:15

Seminari di Cultura Matematica

I ponti oscillano e a volte crollano: perchè?

Filippo Gazzola, Dipartimento di Matematica, Politecnico di Milano

Aula B.2.1 (edificio 14 - Nave ) via Bonardi 9, Milano.

Finite volume schemes are commonly used to construct approximate solutions to conservation laws. In this study we extend the framework
of the finite volume methods to dispersive water wave models, in particular to Boussinesq type systems. We focus mainly on the application of the method to bidirectional non- linear, dispersive wave propagation in one space dimension. Special emphasis is given to
important nonlinear phenomena such as solitary waves interactions,dispersive shock wave formation and the runup of breaking and
non-breaking long waves.

20 Marzo, 2013 14:30 oclock

Sezione di Probabilità Quantistica

Sequential measurements of conjugate observables

Claudio Carmeli, Università di Genova e I.N.F.N.

Aula seminari III piano

abstract

abstract

We apply some earlier results on the classification of covariant instruments in order to clarify some aspects related to sequential measurements of conjugated observables. The results stated are valid both in the finite and infinite dimensional setting. Particular emphasis will be given, in the end, to the finite dimensional applications.

20 Marzo, 2013 15:30 oclock

Sezione di Probabilità Quantistica

Characterization of informational completeness for covariant phase space observables

Jussi Schultz, Politecnico di Milano

Aula seminari III piano

abstract

abstract

Each covariant phase space observable is determined by a unique positive trace one operator. We characterize the informational completeness of these observables in terms of the zero set of the Weyl transform of the generating operator, the relevant condition being that the zero set has dense complement. We then consider two other conditions, namely, that the zero set is of Lebesgue measure zero, or empty. We show that all three conditions are distinct, and show how they are related to approximation theorems in harmonic analysis.

15 Marzo, 2013 14:00

Seminari PhD di Equazioni Differenziali

A fixed point theorem in metric spaces

VITTORINO PATA, Dipartimento di Matematica

Aula seminari III piano

Each covariant phase space observable is determined by a unique positive trace one operator. We characterize the informational completeness of these observables in terms of the zero set of the Weyl transform of the generating operator, the relevant condition being that the zero set has dense complement. We then consider two other conditions, namely, that the zero set is of Lebesgue measure zero, or empty. We show that all three conditions are distinct, and show how they are related to approximation theorems in harmonic analysis.