Archive / Seminari INF / INF_2026_04_24_Nikos_Pitsianis
USI email 2025
 

Università della Svizzera italiana

Faculty of Informatics

 
 
 

INF Seminars

 
 

Space-time efficient compression of all resistance distances on a large sparse network
 

24.04

10:00 - 11:00
USI East Campus, Room D0.02
sample usi
Abstract: The resistance distances, a robust alternative to geodesic distances on a network G(V,E), play a key role in exploratory network analysis across numerous application domains [Klein and Randić, 1993]. However, making the distance matrix Q(G) available and reusable for a large sparse network faced a scaling challenge: memory space for Q scales quadratically with n=|V|, and exact arithmetic computation scales cubically with n in the worst case. We present compressive representations of the distance matrix Q that are provably accurate and efficient. These include particularly the inverse Cholesky factor of the Laplacian matrix, and its submatrices. We provide experimental results on synthetic graphs and real-world networks. Our approach significantly reduces archival memory space compared to existing methods and enables fast elementwise decompression.

Hosts: Dr. Dimosthenis Pasadakis, Prof. Olaf Schenk
 
 

Nikos Pitsianis

Aristotle University of Thessaloniki, Duke University

 

24.04

Friday

Nikos Pitsianis is an Associate Professor at the Aristotle University of Thessaloniki, where he leads the Computer Systems Architecture Laboratory. He is interested in high-performance scientific computing, compiler optimization, and fast algorithms for signal and image processing. He also serves as an Adjunct Professor at Duke University, where he previously held research faculty positions. His industry background includes experience at BOPS Inc. and IBM Research. He holds a PhD in Computer Science from Cornell University.

10:00