Time: May 5, 2022, Thursday, 02:00 PM Eastern Time (US and Canada)
Place: New Computer Science (NCS) Room 220, and Zoom

Zoom link: https://stonybrook.zoom.us/j/95948672934?pwd=d3ZDcUJkK3VweFBDVWhIVDhtaFU2Zz09
Meeting ID:  959 4867 2934
Passcode:  082036

Title:  Generative Adversarial Learning using Optimal Transport

Abstract: 

Generative Adversarial Learning (GAL) aims to learn a target distribution in an adversarial manner. A Generative Adversarial Network (GAN) is a concrete implementation of GAL using a discriminator and a generator that play a min-max game. GANs have been used in many machine learning and computer vision applications. However, GANs are known to be hard to train, mainly because a min-max saddle point optimization problem needs to be solved in GAL. In this thesis, I investigate several methods to improve generative adversarial learning using Optimal Transport (OT). 

Previous Wasserstein GANs (WGANs) do not compute the correct Wasserstein distance to train the discriminator. To address this problem, I propose WGAN-TS that uses the L1 transport cost and computes the correct Wasserstein distance to train the discriminator. To ensure the local convergence of WGANs, I propose WGAN-QC that adopts the quadratic transport cost. I prove that WGAN-QC not only computes the correct Wasserstein distance but also converges to a local equilibrium point. To compute the Wasserstein distance over the whole dataset, I propose to use Semi-Discrete Optimal Transport (SDOT) to match noise points and the real images during GAN training. To measure the quality of an SDOT map, I use the Maximum Relative Error (MRE) and the L_1 distance between the target distribution and the transported distribution obtained by an OT map. I propose statistical methods to estimate the MRE and the L_1 distance. I propose an efficient Epoch Gradient Descent algorithm for SDOT (SDOT-EGD). To deal with the 2D special case of GAL, I propose to use OT to learn 2D distributions. In particular, I adopt OT to match persistent diagrams in training a topology-aware GAN and learn density maps in the crowd counting task. Finally, I use OT and the topological maps of the crowd to improve the crowd counting performance and propose a topology-based metric to measure the quality of the crowd density maps.
The INS (International Neuroethics Society) AI and Consciousness Affinity Group is hosting a talk titled Bringing Trustworthiness in Generative AI and Agentic AI Using Thought Knowledge Graphs featuring speaker Manas Gaur, a computer scientist at UMBC.
The talk will examine the interplay between Thought Knowledge Graphs (TKGs) and how they can form more trustworthy and reasoning-based responses in AI. They will also discuss introducing novel methods on implementing TKGs and their overall impact on creating more trustworthy AI systems.
The talk will be held online via Zoom on Monday, December 2 at 1:00pm (EST).
Register to attend.

AI is everywhere -- and so are the privacy concerns that come with it. At its core, the most common forms of AI we use today are online digital services -- and thus inherit the usual privacy risks of any internet-based tool. However, AI also introduces a set of unique and evolving risks. We'll take a closer look at one of the newest developments in this area: indirect prompt injection -- a technique that can trick AI tools into revealing or extracting private information. You'll learn how this emerging form of AI manipulation works, why it matters, and how to protect yourself -- as well as how similar techniques are being used in academic contexts to manipulate systems and even mislead researchers.

Register for this Zoom workshop.

Making sense of Twitter @ Bloomberg presented by Daniel Preotiuc-Pietro

ABSTRACT: The Bloomberg Terminal has provided ways for investors and journalists to sift through and understand the immense volume of tweets and discover financially-relevant content ever since the SEC approved the use of Twitter for company disclosures back in 2013.

In the first part of the talk, I will showcase how tweets impact financial markets and how Bloomberg is using Natural Language Processing methods to identify financially relevant tweets that move the markets. Our processing pipeline feeds directly to clients, journalists in the newsroom and powers several news analytic products offered by the company including trending companies and consumer sentiment for publicly traded equities.

However, understanding user pragmatic intent in individual tweets would allow us to gain deeper insights and enable new applications. I will present several recent research studies focused on understanding intent including identifying complaints and the roles with which vulgarity is used in social media and how these can help improve applications such as sentiment analysis and hate speech detection.

BIO: Daniel Preotiuc-Pietro is a Senior Research Engineer and Team Lead at Bloomberg LP, where he works on analyzing and building models for real-world large scale social media and news mining and information extraction. His research interests are focused on understanding the social and temporal aspects of text, especially from social media, with applications in domains such as Social Psychology, Law, Political Science and Journalism. Several of his research studies were featured in popular press including the Washington Post, BBC, New Scientist, Scientific American or FiveThirtyEight. He is a co-organizer of the Natural Legal Language Processing workshop series. Prior to joining Bloomberg LP, Daniel was a postdoctoral researcher at the University of Pennsylvania with the interdisciplinary World Well Being Project and obtained his PhD in Natural Language Processing and Machine Learning at the University of Sheffield, UK.
Spring 2026, Wednesdays 2 to 3:20 pm, NCS 220 and Zoom link to be announced soon.

The seminar will be jointly taught by Prof. Dimitris Samaras (samaras@cs.stonybrook.edu).

The overall purpose of this seminar is to bring together people with interests in Computer Vision theory and techniques and to examine current research issues. This course will be appropriate for people who already took a Computer Vision graduate course or already had research experience in Computer Vision.

To enroll in this course, you must either: (1) be in the Ph.D. program or (2) receive permission from the instructors.

Each seminar will consist of multiple short talks (around 15 minutes) by multiple students. Students can register for 1 credit for CSE656. Registered students must attend and present a minimum of 2 talks. Registered students must attend in person. Up to 3 absences will be excused. Everyone else is welcome to attend.

Please note: Exceptionally, the first meeting on 1/28 will be in NCS 120.
What AI tools are available to help with the scholarly research process? Are they helpful? What do they do and is it worth the time and energy to try them out? Join librarian Christine Fena to explore and compare established and emerging AI research tools such as Elicit, Scite, Consensus, and Undermind. The online workshop will provide a starting point to understanding what these tools are, the basics of how they work, and how AI research assistants might bring changes to your search process in the future. All are welcome!



Register here via Zoom.

Abstract: Materials used in extreme environments, such as high temperatures, irradiation, and stress, often fail due to rapid defect generation and microstructural evolution, and traditional approaches cannot explore the vast design space needed for next-generation alloys. I will present a machine learning framework powered by massive computing that links individual atomic motion to microstructural evolution. Neural network kinetics models trained on first-principles data map vacancy barrier spectra and capture correlated diffusion in multicomponent alloys, revealing design strategies to suppress radiation damage. At larger scales, simulations uncover dislocation patterning and distinguish between confined and extended slip bands, offering new insight into collective dislocation motion and deformation instabilities. By integrating AI-driven modeling, large-scale computing, and experimental validation, my research goal is to accelerate the discovery of damage-tolerant materials and advance fundamental understanding of defect physics in extreme environments.

Speaker Bio: Penghui Cao is an Associate Professor in Mechanical and Aerospace Engineering at the University of California, Irvine, with a joint appointment in Materials Science and Engineering. He received his PhD in mechanical engineering from Boston University and subsequently worked as a Postdoctoral Associate in the Department of Nuclear Science and Engineering at the Massachusetts Institute of Technology from 2014 to 2018. Dr. Cao's research focuses on understanding the fundamental mechanisms that govern radiation responses and microstructure evolution in materials, and on developing advanced alloys for high-performance nuclear energy systems. His lab advances computational and modeling algorithms, integrates advanced manufacturing techniques to tailor microstructures, and leverages state-of-the-art electron microscopy to characterize and assess underlying mechanisms. He is the recipient of the DOE Early Career Research Program Award and the UCI Samueli School's Mid-Career Award for Faculty Excellence in Research.

Location: Institute for Advanced Computational Science, Seminar Room

*This seminar will be held in-person and online. Zoom link below*

Join Zoom Meeting: https://stonybrook.zoom.us/j/96410717491?pwd=3WGMwbLYNMSbI2IF160VXkvv2JmCQ1.1

Meeting ID: 964 1071 7491
Passcode: 399333

Join Klaus Mueller, professor of computer science and interim chair of the Department of Technology and Society, as he hosts Sucheta Lahiri.

Lahiri leads the AI Ethics and Risk Management function at Oxy, where she is responsible for ensuring that the company's AI solutions are developed and deployed in a manner that is ethical, efficient, trustworthy, safe, sustainable, and human-centered. She holds a doctorate from Syracuse University, along with two master's degrees in Applied Statistics and Information Science earned in India.

Zoom: https://stonybrook.zoom.us/j/7851507944?omn=98268154363#success

Zoom Link: https://stonybrook.zoom.us/j/98533029054?pwd=5FXO6lWGTJssCADEYkYbA7sjaacPRX.1

Meeting ID: 985 3302 9054

Passcode: 436997

Abstract:

Semantic segmentation, the task of assigning a semantic label to each pixel in an image, is a fundamental problem in the field of Computer Vision. with crucial applications in domains like autonomous driving, drone imagery and medical image analysis. Despite advancements in deep learning architectures, state-of-the-art models still heavily depend on large-scale pixel-level annotations, which are costly and time-consuming to acquire. To address this issue, Semi-Supervised Segmentation (SSS) has emerged as a promising solution, leveraging a small set of labeled images alongside a larger corpus of unlabeled data to reduce the annotation burden. In this proposal, I aim to investigate the challenges of SSS and propose approaches to address them. Existing SSS methods rely on a teacher-student framework to generate pseudo-labels for unlabeled images, which are then used for model training. However, this approach presents two major challenges. Pixel-level consistency fails to effectively capture contextual information, and pseudo-labels are noisy, especially in the early stages of training. To address the challenge of noisy pseudo-labels, existing methods rely on confidence-based thresholding to identify reliable pseudo-labels. However, during early training phases, when the model is poorly calibrated, this approach can select high-confidence but noisy pseudo-labels. To address this, we propose a novel approach that reduces reliance on model confidence to select reliable pseudo-labels. Our method employs an ensemble of a segmentation model and an object detection model to select more reliable pseudo-labels, which are then used to weight pseudo-labels using rank statistics, reducing the influence of noisy labels in training. Next, to address both the challenge of capturing contextual information and noisy pseudo-labels I introduce a novel Multi-scale Patch-based Multi-label Classifier (MPMC), which incorporates patch-level contextual information and reduces the impact of noisy pixel pseudo-labels by using the predictions of the patch-level Multi-label classifier to detect noisy labels, enhancing overall segmentation performance. While my work so far has focused on effectively utilizing unlabeled data to improve segmentation performance, as part of our future work, I will explore the use of textual information, such as category descriptions, for segmentation tasks. In limited labeled data scenarios it is more challenging to align visual features with textual features from large language models (LLMs).