Lisette Elizabeth Espín Noboa

Doktorandenkolloquium von Lisette Elizabeth Espín Noboa

Vortragender: Lisette Elizabeth Espín Noboa

Datum & Uhrzeit: 31.10.2018, 17 c.t. Uhr, Gebäude G 209

Gastgeber: JProf. Claudia Wagner

Titel: The Semantics and Structure of Edge Formation in Networks

Abstract:

In this thesis we propose methods to compare the explanatory power of mechanisms of edge formation in networks. Given the edges of a network it is an ongoing problem to infer the mechanisms, i.e., rules and conditions, which led to these edges’ creation. While it is often simple to devise a list of hypothetical mechanisms, it remains hard to decide which hypothesis is closest to reality. The difficulty of the problem increases when hypothesis are solely based on network structure and no further meta-data is available. To solve this problem we propose two approaches: HOPSurfer and Janus. HOPSurfer, a biased random walker, is able to evaluate hypothesis that are based on network structure alone. Its key concept is a model of information foraging on networks based on transition probabilities between k-HOP neighborhoods. When meta-data is available, Janus, a Bayesian framework, allows to rank hypotheses by relative plausibility. We use it to identify plausible hypotheses in cases where nodes carry additional meta-data. For cases where meta-data on nodes is scarce, we further introduce and evaluate a set of guidelines for improving the accuracy of meta-data inference when no ground truth is available. We demonstrate the utility of our methods on both, synthetic and empirical networks.

 

Wann 31.10.2018
von 17:15 bis 18:00
Wo G 209
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