naXys Newsletter – January 2019 – Namur Institute For Complex Systems

Newsletter – January 2019

UPCOMING SEMINARS

Information Diffusion on Twitter: exploiting the timings of Retweets, Martin Gueuning (UNamur), February 14, 13:00 – 14:00, E25
Climate event attribution using multivariate peaks-over-thresholds modelling, Anna Kiriliouk (UNamur), February 21, 13:00 – 14:00, E25
TBD, Ines Wilms (Maastricht University), Mars 7, 13:00 – 14:00, E25

Abstracts can be found on our website: https://www.naxys.be/events

NEWS

NAXYS EVENT BY PRINCIPIAE. naXys is pleased to welcome Dr. Jean-Luc Doumont for his international conference “Making the most of your presentation”. Do not miss this opportunity and register here.

PUBLICATION IN SCIENCE ADVANCES. A recent work of naXys researchers Malbor Asllani, Renaud Lambiotte and Timoteo Carletti on network science has been published in the prestigious journal Science Advances. More info

Network science has emerged, in the past 20 years, as an essential framework to model and understand complex systems in a variety of disciplines, including physics, economics, biology, and sociology.

At its core, network science views a system as a set of nodes that may be connected directly by an edge or indirectly by a succession of edges, thereby forming paths of interactions; while a sequence of links will represent indirected interactions. The bridge between network structure and dynamics is generally unraveled by defining a linear dynamical model on the nodes.

In this work they have analysed a large ensemble of real networks, arising from different disciplines and we have proved that they are often strongly “non-normal”. This non-normality has a peculiar impact of the system behaviour: small initial perturbations can be strongly amplified and radically modify the system stability. The consequences of this theoretical work are manyfold, in particular it could help to better understand the resilience of ecosystems or financial ones to external shocks.

Reference: Asllani M., Lambiotte R., and Carletti T., Structure and dynamical behavior of non-normal networks, Science Advances, 12 Dec 2018, Vol. 4, no. 12, eaau9403

PUBLICATION IN NATURE COMMUNICATIONS. The work of naXys researcher Alexandre Bovet has recently been published in Nature communications. More info

Abstract: The dynamics and influence of fake news on Twitter during the 2016 US presidential election remains to be clarified. Here, we use a dataset of 171 million tweets in the five months preceding the election day to identify 30 million tweets, from 2.2 million users, which contain a link to news outlets. Based on a classification of news outlets curated by www.opensources.co, we find that 25% of these tweets spread either fake or extremely biased news. We characterize the networks of information flow to find the most influential spreaders of fake and traditional news and use causal modeling to uncover how fake news influenced the presidential election. We find that, while top influencers spreading traditional center and left leaning news largely influence the activity of Clinton supporters, this causality is reversed for the fake news: the activity of Trump supporters influences the dynamics of the top fake news spreaders.

Reference: Bovet, A. & Makse, H.A., 2019, Influence of fake news in Twitter during the 2016 US presidential election, Nature Communications, Vol. 10, Numéro 1, 7, p. 7.

UPCOMING PhD COURSE IN APPLIED ECONOMETRICS, Spring 2019, UNamur. The course aims to provide an overview of up-to-date techniques of nonlinear modelling and extreme values modelling. It is design to help prepare students for research in the area of economics and finance. The course starts with a presentation of the platform of High Performance Computing from FWB and a brief overview of the Python language. More info

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