Title: Statistical Viewpoints on network modeling and deep learning
Date: Nov 18th , 2022
Time: 8:00 - 9:00 AM EST
Meeting Link:
https://gatech.zoom.us/j/8833061674
Namjoon Suh
Machine Learning PhD Student
School of Industrial & Systems Engineering
Georgia Institute of Technology
Committee
1 Dr. Huo, Xiaoming (Advisor, ISyE, Gatech)
2 Dr. Mei, Yajun (Co-advisor, ISyE, Gatech)
3 Dr. Kang, Sung ha (Mathematics, Gatech)
4 Dr. Zhilova, Mayya (Mathematics, Gatech )
5 Dr. Zhou, Ding-Xuan (School of Mathematics and Statistics, The university of Sydney)
Abstract
In my thesis presentation, two of my works will be presented:
- A new statistical model for network data : We propose a combined model, which integrates the latent factor model and a sparse graphical model, for network data. It is noticed that neither a latent factor model nor a sparse graphical model alone may be sufficient to capture the structure of the data. The proposed model has a latent (i.e., factor analysis) model to represent the main trends (a.k.a., factors), and a sparse graphical component that captures the remaining ad-hoc dependence. Model selection and parameter estimation are carried out simultaneously via a penalized likelihood approach. The convexity of the objective function allows us to develop an efficient algorithm, while the penalty terms push towards low-dimensional latent components and a sparse graphical structure. The effectiveness of our model is demonstrated via simulation studies, and the model is also applied to four real datasets: Zachary's Karate club data, Kreb's U.S. political book dataset (http://www.orgnet.com), U.S. political blog dataset, and citation network of statisticians; showing meaningful performances in practical situations.
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- New insights in approximation theory and statistical learning rate of deep ReLU network: This work provides the rigorous theoretical analysis on how the approximation rate and learning rate (i.e., excess risk) behave when deep ReLU fully connected network is used as a function approximator (estimator) when ground-truth functions are assumed to be in Sobolev spaces defined over unit sphere. With the help of spherical harmonic basis, we track the explicit dependence on data dimension d in the rates and prove that deep ReLU net can avoid “the curse of dimensionality” when the function smoothness is in the order d as d tends to infinity. This discovery is not something observed in the state-of-the-art result in deep learning theory; specifically, when the function is defined on d-dimensional cube, or convolutional neural networks are used as the function approximator.
- In Campus Calendar
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No
- Groups
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Graduate Studies
- Invited Audience
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Faculty/Staff, Public, Undergraduate students
- Categories
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Other/Miscellaneous
- Keywords
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Phd Defense
- Status
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- Created By: Tatianna Richardson
- Workflow Status: Published
- Created On: Nov 11, 2022 - 12:01pm
- Last Updated: Nov 11, 2022 - 12:02pm