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Data Science Colloquium: F. Chiaromonte (SSSup)
Data Science Colloquium: F. Chiaromonte (SSSup)
Starts: 13:00
Ends: February 14, 2018  14:30
Location: Aula 3, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33, Pisa
Description: Title: Statistics for large, complex data and its role in "Omics" research
Abstract: In this talk, we will provide an overview of several classes of statistical methods relevant in “Omics” sciences – as well as other scientific fields that rely on the analysis of large, complex data sets. These include (i) feature selection and dimension reduction, two different approaches for handling high dimensional supervised problems; (ii) feature screens for ultrahigh dimensional supervised problems; and (iii) functional data analysis for investigating shapes. In addition to general context and notions, we will provide pointers to recent developments, and describe some specific “Omics” applications.

Seminario M. Tanzi
Seminario M. Tanzi
Starts: 16:30
Ends: February 14, 2018  17:30
Location: Sala Conferenze, Centro di Ricerca Matematica Ennio De Giorgi, Collegio Puteano
Description: Title: Heterogeneously Coupled Maps: Rigorous Mean Field Reduction and Dynamics Reconstruction
Speaker: Matteo Tanzi (University of Victoria, Canada)
Abstract:A graph with heterogeneous degrees has most of its nodes making a small number of connections, while the remaining ones, called hub nodes, have a very high degree. This type of graph is ubiquitously found in models of natural and artificial systems made of interacting components such as, among others, neuronal networks, generegulatory networks, and power grids. I will report recent results addressing the ergodic theoretical properties of expanding dynamical systems coupled on these graphs. The attention is focused on the case where the number of nodes in the graph is very large. This highdimensional systems have a regime of the coupling strength where the interaction is small for poorly connected systems, but large for the hub nodes. In particular, global hyperbolicity might be lost. It is shown that, under certain hypotheses, the dynamics of the hubs can be generically well approximated by a lowdimensional hyperbolic system for exponentially long time in the size of the network. Even if this describes only a long transient, it could be the only behaviour observed in experiments. The results above justify the emergence of macroscopic behaviour such as coherence of dynamics among hubs with the same number of connections. They also suggest an algorithm to reconstruct the network structure and dynamical features from observations of the dynamics at every node. Tested on computer simulations, the algorithm is able to effectively recover the degree distribution of the network, community structures, local dynamics and effective coupling. Furthermore, it is shown to work in a much wider variety of cases than that covered by the rigorous results.
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Seminar  L. Campi (LSE)
Seminar  L. Campi (LSE)
Starts: 11:00
Ends: February 15, 2018  13:00
Location: Aula Mancini
Description: Title : Nonzerosum stochastic differential games with impulse controls: a verification theorem with applications
Abstract: We consider a general nonzerosum impulse game with two players. The main mathematical contribution of the paper is a verification theorem which provides, under some regularity conditions, a suitable system of quasivariational inequalities for the value functions and the optimal strategies of the two players. As an application, we study an impulse game with a onedimensional state variable, following a realvalued scaled Brownian motion, and two players with linear and symmetric running payoffs. We fully characterize a Nash equilibrium and provide explicit expressions for the optimal strategies and the value functions. We also prove some asymptotic results with respect to the intervention costs. Finally, we consider two further nonsymmetric examples where a Nash equilibrium is found numerically.
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Seminar  P. Dai Pra (Unipd)
Seminar  P. Dai Pra (Unipd)
Starts: 11:30
Ends: February 16, 2018  13:00
Location: Aula Fermi
Description: Title : Rhythmic behavior in complex stochastic dynamics
Abstract: Interacting particle systems may exhibit, in the thermodynamic limit, a timeperiodic behavior in the evolution of their law. We have made an attempt to understand which factors may produce this phenomenon, in particular those related to the timesymmetry breaking of the dynamics: dissipation, delay, asymmetry in the interaction. We will first review some examples of mean field dynamics for which the thermodynamic limit can be explicitly computed and analyzed. Later we will focus on some partial results concerning the first, to our knowledge, example of rhythmic behavior for a system with local interaction: the Ising model with dissipation.
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Deadline for application  Spring School COMPLEX NETWORKS: THEORY, METHODS, AND APPLICATIONS
Deadline for application  Spring School COMPLEX NETWORKS: THEORY, METHODS, AND APPLICATIONS
Starts: 10:00
Ends: February 18, 2018  11:00
Description: Lake Como School of Advanced Studies
Villa del Grumello, Como, Italy, 1418 May 2018
http://ntmd.lakecomoschool.org
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