University at Albany
 

Colloquium

To receive schedule updates by email, contact the Colloquium Chair, Prof. Marius Beceanu.
The colloquium usually meets on Friday at 3:00 pm in room ES-143.
The colloquium is partially supported from the Simons grant #584738 (Cristian Lenart)

Yiming Ying (University at Albany)
Online AUC Maximization in Machine Learning
Friday, September 6, 2019
3:00 p.m. in ES-143

Abstract: Stochastic optimization algorithms such as stochastic (online) gradient descent (SGD) update the model sequentially with cheap per-iteration costs, making them amenable for big streaming data analysis. However, most of the existing studies focus on the classification accuracy which can not be directly applied to the important problem of maximizing the Area under the ROC curve (AUC) in imbalanced classification and bipartite ranking. In this talk, I will present our recent work on developing novel SGD-type algorithms for AUC maximization. Our new algorithms can process the streaming data in a sequential manner, which are achieved through innovative interactions between machine learning and applied mathematics. Compared with the existing work which requires high storage and per-iteration costs, our algorithms have both space and per-iteration costs of one datum while achieving optimal convergence rates.

Distinguished Lecture: Vyjayanthi Chari (UC Riverside)
Cluster Algebras and Monoidal Categorification
Friday, October 25, 2019
3:00 p.m. in LC-20

Abstract: Cluster Algebras were introduced by Fomin and Zelevinsky at the turn of the century to understand questions on total positivity in Lie theory. The subject is a now a very active area of research and has many interesting connections and unexpected applications in geometry, combinatorics, and representation theory. In 2009, Hernandez and Leclerc introduced the notion of monoidal categorification of cluster algebras; namely realizing the cluster algebra as the Grothendieck ring of a certain tensor category. In this talk we shall first give a gentle introduction to these ideas. We then discuss some recent work with Matheus Brito which makes further connections with Macdonald polynomials and Demazure modules.

Alexander Powell (Vanderbilt University)
TBA
Friday, November 1, 2019
3:00 p.m. in ES-143

Abstract: TBA

Rongwei Yang (University at Albany)
TBA
Friday, November 15, 2019
3:00 p.m. in ES-143

Abstract: TBA

Suvrit Sra (MIT)
TBA
Friday, December 6, 2019
3:00 p.m. in ES-143

Abstract: TBA

Colloquia from past semesters