2026-09-19T12:25:49Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/120391 2023-09-05 col_2142_5131 col_2142_10761 com_2142_5130 com_2142_10755 com_2142_234

Abdelzaher, Tarek 2023-05 application/pdf en text Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-05-01 The student, Dachun Sun, accepted the attached license on 2023-04-19 at 18:31. The student, Dachun Sun, submitted this Thesis for approval on 2023-04-19 at 18:37. This Thesis was approved for publication on 2023-04-20 at 14:53. DSpace SAF Submission Ingestion Package generated from Vireo submission #19052 on 2023-09-01 at 17:13:45 A structured matrix factorization method for computational modeling of hierarchical polarization in social interactions Sun, Dachun 2023-04-20 Polarization Belief Estimation Hierarchical Matrix Factorization Unsupervised Many works on social interaction polarization detection focus heavily on flat classification of stances and beliefs. We extend them in this work in two important aspects: (i) detects both points of agreement and disagreement between groups, and (ii) divides them hierarchically to represent nested patterns of agreement and disagreement given a structural guide. For example, two opposing parties might disagree on core issues. Moreover, a disagreement might occur on further details within a party, despite agreement on the fundamentals. We call such scenarios hierarchically polarization. An unsupervised Non-negative Matrix Factorization (NMF) algorithm is described for the computational modeling of hierarchical polarization in social interactions. The algorithm is enhanced with a language model and a proof of orthogonality of factorized components. We evaluate it on both synthetic and real-world datasets, demonstrating the ability to decompose overlapping beliefs hierarchically. In the case where polarization is flat, we compare it to the prior art and show that it outperforms state-of-the-art approaches for polarization detection and stance separation. An ablation study further illustrates the value of individual components, including new enhancements. Thesis eng https://hdl.handle.net/2142/120391 Copyright 2023 Dachun Sun M.S. Thesis Computer Science University of Illinois at Urbana-Champaign Computer Science