Category Archives: Alex

ISI Fellows 2013

Alex Vespignani inducts Fil Menczer as ISI Fellow
Alex Vespignani inducts Fil Menczer as ISI Fellow

On June 27, 2013, in Turin, within the celebrations of the Lagrange Prize and ISI Foundation’s 30th anniversary, Fil Menczer and nine other scientists were named ISI Fellows. The recognition is a tribute to researchers whose scientific contribution is of primary importance for the Institute.  The official investiture took place on June 28th, 2013, during the conference The Being of Science, which highlighted the ways in which the Fellows’ research fields intertwine with the ISI scientific activities.

LaNeT-vi visualization featured on the cover of Nature Physics

Cover of Nature Physics Nov. Edition

LaNeT-vi, a program that represents large-scale networks in two-dimensions, was used to create the cover image for the November edition of Nature Physics. The featured image highlights several nodes in the foreground that stand out from the rest of the network, highlighting the main thrust of the journal’s cover story; the most efficient spreaders in a network are not necessarily the most connected or central. Instead, efficient spreading correlates with spreader location within the core of the network as determined by the k-shell decomposition analysis.

Determining what makes an efficient spreader in a network is essential for optimizing network efficiency and the deployment of resources. As a publicly-available online tool, LaNeT-vi assists in this effort by allowing users to upload their own networks and receive original renderings of their information based on the k-core decomposition.

LaNeT-vi was developed in-house at the School of Informatics and Computing at Indiana University in collaboration with the CNRS, France and the CONICET in Argentina.

New article published in Physical Review Letters puts forth new model of online popularity dynamics

Online popularity can be thought of as analogous to an earthquake; it is sudden, unpredictable, and the effects are severe. While shifts in online popularity are not inherently destructive – consider the unprecedented magnitude of online giving via Twitter following the disaster in Haiti – they indicate radical swings in society’s collective attention. Given the increasingly profound effect that large-scale opinion formation has on important phenomena like public policy, culture, and advertising profits, understanding this behavior is essential to understanding how the world operates.

In this paper by Ratkiewicz and colleagues, the authors put forth a web-wide analysis that includes large-scale data sets of the online behaviors of millions of people. The paper offers a novel model that is is capable of reproducing all of the observed dynamics of online popularity through a mechanism that causes sudden, nonlinear bursts of collective attention. These results have been mentioned in the APS and PhysOrg websites.

Article in Nature on the plenitude of scientific performance metrics features the research of Bollen and Vespignani

The relatively new field of bibliometrics has experienced an explosion of research as scientists become more interested in developing metrics that can accurately measure scientists’ performance. The common but naive practice of tallying the number of journal citations accumulated by researchers has serious limitations insofar as many salient factors like the weight of a citation as a function of a journal or database’s popularity, how well an article integrates with contemporaneous research, and individual productivity are not taken into account.

The article discusses Bollen’s concern that the scramble to uncover new metrics and combinations of them has obscured an equal need to define the concepts under measurement more rigidly. It also addresses an approach taken by Vespignani and colleagues to apply the concept of weighted citations to develop a network of over 400,000 papers published over 100 years in order to demonstrate the variable influence scientists have over the scientific community. Read more…

CNetS team shows new levels of refinement in predicting human mobility, epidemic spread

human mobility patternsThe interplay of human mobility patterns like those between local metropolitan commuters and long-range airline travelers during a global epidemic can be modeled in such detail so as to offer refined views of epidemics that could aid in public health emergency decision making, according to new research published by Professor Alessandro Vespignani’s research team at Indiana University. The findings, published this week in the Proceedings of the National Academy of Sciences‘ Online Early Edition, also note that with these refined computational strategies, new levels of accuracy about the behavior of targeted mobility networks and epidemic progression can be imagined. Contributing with Vespignani on the paper were research scientists Duygu Balcan and Bruno Goncalves of the IU School of Informatics and Computing, and the Pervasive Technology Institute, IU Physics Department graduate student Hao Hu and research scientists Vittoria Colizza and Jose Ramasco of the Institute for Scientific Interchange Foundation in Torino, Italy.  More…

Bringing H1N1 vaccine is a race against time says Professor Vespignani

Professor Vespignani speaks on H1N1 vaccine
Professor Vespignani speaks on H1N1 vaccine

As Hoosiers roll up their sleeves to take the seasonal flu shots, researchers state that the H1N1 vaccination may take longer to arrive for large scale inoculation than anticipated. “It’s a race against time,” said IU School of Informatics professor Dr. Alessandro Vespignani who was on his way to an H1N1 conference Tuesday. He says by the time the vaccine is widely available, “it’s likely to have the peak of the disease earlier than an appreciable percentage of the population will be vaccinated.” He believes the H1N1 virus should hit its peak by about Halloween. By then, half of those who are going to get ill will have gotten sick, and only then will large supplies be available. “There is no need to panic. The disease is mild, it is under the constant attention of authorities,” Dr. Vespignani said. More…