Si avvisa che in data 2-4-2019, alle ore 15:00 precise, presso l'Aula
Seminari "F. Saleri" VI piano, Dipartimento di Matematica, Politecnico di
Milano, si svolgerà il seguente seminario:
Relatori
Karel Hron e Jitka Machalova, Palacky University Olomouc, Czech Republic
Titolo
Simplicial splines for representation of density functions
Abstract
In the context of functional data analysis, probability density functions as
non-negative functions are characterized by specific properties of scale
invariance and relative scale which enable to represent them with the unit
integral constraint without loss of information. On the other hand, all
these properties are a challenge when the densities need to be approximated
with spline functions, including construction of the respective B-spline
basis. The Bayes space methodology of density functions enables to express
them as real functions in the standard L2 space using the clr
transformation. The resulting functions possess the zero integral
constraint. This is a key to propose a new B-spline basis, holding the same
property, and consequently to build a new class of spline functions, called
simplicial splines, which can approximate probability density functions in a
consistent way. The contribution provides also construction of smoothing
simplicial splines and possible orthonormalization of the B-spline basis
which might be useful in some applications. Finally, a concise analysis
using simplicial splines is demonstrated with anthropometric data for the
case of simplicial functional principal component analysis.
Tutti gli interessati sono invitati a partecipare.
Cordiali saluti,
Alessandra Menafoglio
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Alessandra Menafoglio
MOX - Dept. of Mathematics
Politecnico di Milano
Piazza Leonardo da Vinci, 32,
20133, Milan Italy
Phone: +39 02 2399 4642
Email: <mailto:alessandra.menafoglio@polimi.it>
alessandra.menafoglio(a)polimi.it