Dear all,
Next week, we have the pleasure of having Dr. Yuval Dagan give a talk in
the colloquium.
The seminar will be held on Monday, January 8th at 14:00.
Location: C220.
The title, abstract and bio appear below.
Looking forward to seeing you,
Sagie and Liat
*Title:*
Learning from dependent data and its modeling through the Ising model
*Abstract:*
I will present a theoretical framework for analyzing learning algorithms
which rely on dependent, rather than independent, observations. While a
common assumption is that the learning algorithm receives independent
datapoints, such as unrelated images or texts, this assumption often does
not hold. An example is data on opinions across a social network, where
opinions of related people are often correlated, for example as a
consequence of their interactions. I will present a line of work that
models the dependence between such related datapoints using a probabilistic
framework in which the observed datapoints are assumed to be sampled from
some joint distribution, rather than sampled i.i.d. The joint distribution
is modeled via the Ising model, which originated in the theory of Spin
Glasses in statistical physics and was used in various research areas. We
frame the problem of learning from dependent data as the problem of
learning parameters of the Ising model, given a training set that consists
of only a single sample from the joint distribution over all datapoints. We
then propose using the Pseudo-MLE algorithm, and provide a corresponding
analysis, improving upon the prior literature which necessitated multiple
samples from this joint distribution. Our proof benefits from sparsifying a
model's interaction network, conditioning on subsets of variables that make
the dependencies in the resulting conditional distribution sufficiently
weak. We use this sparsification technique to prove generic concentration
and anti-concentration results for the Ising model, which have found
applications beyond the scope of our work.
Based on joint work with Constantinos Daskalakis, Anthimos Vardis Kandiros,
Nishanth Dikkala, Siddhartha Jayanti, Surbhi Goel and Davin Choo.
*Bio*:
Yuval Dagan is a postdoctoral researcher at the Simons Institute for the
Theory of Computing at UC Berkeley and at the Foundations of Data Science
Institute (FODSI). He received his PhD from the Electrical Engineering and
Computer Science Department at MIT, advised by Professor Constantinos
Daskalakis (2018-2023). He received his Bachelor’s and Master’s degrees
from the Technion, where he was advised by Professor Yuval Filmus
(2011-2017). During his PhD, he received the Meta Research Fellowship in
Machine Learning (2021-2022). Further, he was a visitor of the Simons
Foundation at the Causality program (2022) and a research intern at Google
Mountain View, hosted by Vitaly Feldman (2019). Prior to his PhD, he was a
research assistant of Professor Ohad Shamir at Weizmann Institute (2018).