Talk: Alex Arenas visits DiMeNet

Alex Arenas gave a talk today about his research on multiplex networks. Alex is a professor of computer science and mathematics at the Universitat Rovira i Virgili. The title and abstract of his talk are below.

Ranking nodes by versatility

The determination of the most central agents in complex networks is important because they are responsible for a faster propagation of information, epidemics, failures and congestion, among others. A challenging problem is to identify them in networked systems characterized by different types of interactions, forming interconnected multilayer networks. Here we describe a mathematical framework that allows us to calculate centrality in such networks and rank nodes accordingly, finding the ones that play the most central roles in the cohesion of the whole structure, bridging together different types of relations. These nodes are the most versatile in the multilayer network. We investigate empirical interconnected multilayer networks and show that the approaches based on aggregating—or neglecting—the multilayer structure lead to a wrong identification of the most versatile nodes, overestimating the importance of more marginal agents and demonstrating the power of versatility in predicting their role in diffusive and congestion processes.

Talk: Franziska Barbara Keller visits DiMeNet

Franziska Barbara Keller gave a talk today about her research on political networks in China. Franziska is a Post-Doctoral Fellow at Columbia University. The title and abstract of her talk are below.

Networks of Power: How Social Network Analysis can tell us who will rule and who is really in charge in the Chinese Communist Party (CCP)

Patronage networks are said to grant access to a regime’s inner circle, but only the ties to powerful leaders have been studied systematically. I examine the whole informal CCP elite network, noting who has been promoted under whom in the past. Coworker – but not province or alumni – ties to patrons double the chances of becoming a Politburo member, but links to former subordinates also have positive effects – unlike those to former superiors. I also show that we do not need to rely on contested insider information to identify the patrons first: popularity as coalition partner along network ties alone (closeness centrality) allows predicting Politburo appointments up to 10 years ahead. The patrons themselves hold (betweenness central) network positions from where they can more easily suppress challenges from within. The paper illustrates how social network analysis can add the “informal politics” dimension to the research on authoritarian regimes focused on formal institutions.

Talk: Brooke Foucault Welles visits DiMeNet

brooke foucault-welles
Brook Foucault Welles gave a talk today about her research on hashtag activism. Brooke is an Assistant Professor of Communication at Northeastern University and faculty affiliate of the Network Science Institute. The title and abstract of her talk are below.

#HashtagActivism: Networked Counterpublics in the Digital Age

The proliferation of social media has given rise to widespread study and speculation about the impact of digital technologies on politics, activism, and social change. Key among these debates is the role social media play in shaping the contemporary public sphere, and by proxy, our democracy. Maligned by some as “slacktivism,” I will argue social computing platforms such as Twitter create unique opportunities for traditionally excluded voices to challenge the terms of public debate. Counterpublics, or the alternative spheres of debate created by marginalized voices, have long played the important role of highlighting and legitimizing the experiences of those at the margins as they push for integration and change in the mainstream public sphere. Using the evidence from the Twitter hashtags #myNYPD and #Ferguson, I will demonstrate how networked counterpublics and hashtag activism are increasingly complementing offline counterpublic spheres to change the terms of mainstream public debates about racial justice and police violence in America.

Media: NewsWorks Interview


Sandra talked today to Dave Heller in NewsWorks Tonight.

In 1970, Gil Scott-Heron penned the poem and song “The Revolution will not be Televised.” Five years ago, Malcolm Gladwell, author of “The Tipping Point” opined that the revolution will not be Tweeted. Well now that notion is being challenged by a new study analysis of tens of millions of tweets. NewsWorks Tonight Host Dave Heller discussed the study with its co-author, Sandra Gonzalez-Bailon, professor at the Annenberg School for Communications at the University of Pennsylvania.