This role is part-time 0.6 FTE (21.9 hours pw)
We are looking to recruit one of two Finance Assistants who play a key role in ensuring the Mathematical Institute’s financial transactions are recorded and processed accurately and in line with the University’s financial controls. You will report to the Finance Officer (General Ledger).
14:00
Dr. Guillaume St-Onge
Abstract
TBA
14:00
What we do in the shadows: mining temporal motifs from transactions on the Dark Web
Abstract
In this talk, I propose the use of temporal motif counting, as a way of monitoring both the system as a whole and the users within it. Focusing on the Alphabay and Hydra dark markets, I study all the motifs formed by three sequential transactions among two to three users, finding that they can tell us something more complex than can be captured by simply degree or transaction volume. Studying motifs local to the node, I show how users form salient clusters, which is a promising route for classification or anomaly detection tasks.
14:00
Laplacian renormalization group for heterogeneous networks
Note: we would recommend to join the meeting using the Zoom client for best user experience.
Pablo's main research interests concern complex systems in various fields, from biology to self-organized criticality theory, both from a theoretical and an applicative point of view.
As for the theoretical aspect, he contributed to the definition of mesoscopic models of the dynamics of the cortex, to the analysis of Griffiths Phases in complex networks. In term of applied works, he conducted an analysis of emerging patterns in tropical forests, such as those of Barro Colorado in Panama.
In this seminar, Pablo will present his recent work titled "Laplacian renormalization group for heterogeneous networks", published in Nature Physics earlier this year (link to the paper below).
Article: https://www.nature.com/articles/s41567-022-01866-8
Join Zoom Meeting
https://zoom.us/j/99314750082?pwd=L3kvZVh0TVJNRnk5Tm95YUpVODVRZz09
Meeting ID: 993 1475 0082
Passcode: 669691
Abstract
Complex networks usually exhibit a rich architecture organized over multiple intertwined scales. Information pathways are expected to pervade these scales reflecting structural insights that are not manifest from analyses of the network topology. Moreover, small-world effects correlate with the different network hierarchies complicating identifying coexisting mesoscopic structures and functional cores. We present a communicability analysis of effective information pathways throughout complex networks based on information diffusion to shed further light on these issues. This leads us to formulate a new renormalization group scheme for heterogeneous networks. The Renormalization Group is the cornerstone of the modern theory of universality and phase transitions, a powerful tool to scrutinize symmetries and organizational scales in dynamical systems. However, its network counterpart is particularly challenging due to correlations between intertwined scales. The Laplacian RG picture for complex networks defines both the supernodes concept à la Kadanoff, and the equivalent momentum space procedure à la Wilson for graphs.
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