Jan

24

2022

Today we are confronted with huge and highly complex data and one main challenge is to determine the "structure" of complex networks or ''shape'' of data. In the past few years, geometric and topological methods, as powerful tools that originated from Riemannian geometry, are becoming popular for data analysis. In this seminar, after introducing Ollivier-Ricci curvature for (directed) hypergraphs, as one of the main applications, I will present the result of the implementation of this tool for the analysis of chemical reaction networks.

Jan

25

2022

Nakada’s α-expansions move from the regular continued fractions (α = 1), Hurwitz singular continued fractions (obtained at α =(-1+\sqrt{5})/2 ), and nearest integer continued fractions (α=1/2), to more unusual cases for α less than sqrt{2}-1. This talk will look at similar continued fraction expansions with odd partial quotients. I will describe how restricting the parity of the partial quotients changes the Gauss map and natural extension domain. This is joint work with Florin Boca as well as Yusef Hartono, Cor Kraaikamp, and Niels Langeveld.

Jan

26

2022

The growth rate estimation of SARS-CoV-2 positive cases is crucial for understanding the evolution of the pandemic. We propose a method for estimating the growth rate of the proportion of positive cases in England and its local authorities. The proposed Bayesian model incorporates a Gaussian process as a latent effect, employed to compute the growth rate and higher derivatives. This method does not make assumptions about generation times and can be adapted to different spatial geographies and population subgroups.

Jan

28

2022

Jan

31

2022