Yihui Ren

AI Department, Brookhaven National Laboratory

Abstract: Artificial intelligence is rapidly changing how we approach scientific discovery and engineering design. However, realizing the potential of modern AI in scientific domains requires going beyond simply applying models developed for natural language: scientific data have distinct structures, and scientific workflows often require tight integration among learned representations, domain knowledge, simulation, and numerical optimization.
In this talk, I will present two recent efforts that explore complementary directions for building AI systems for science and engineering. First, FM4NPP investigates whether the foundation-model paradigm can scale to experimental nuclear and particle physics. Using more than 11 million particle-collision events, we develop a self-supervised learning framework for sparse detector data and demonstrate scaling up to 188 million parameters. The resulting representations generalize across diverse downstream tasks and enable data-efficient adaptation with lightweight task-specific components.
Second, I will present AutoSizer, an LLM-driven framework for automatic sizing of analog and mixed-signal circuits. Rather than asking an LLM to perform numerical optimization directly, AutoSizer uses the LLM as a reasoning and orchestration layer that interprets circuit behavior, analyzes simulation feedback, and adaptively refines the optimization process.
Together, these studies illustrate two complementary roles for modern AI in scientific workflows: learning reusable representations from complex scientific data and reasoning over computational tools to guide challenging design and optimization problems. I will discuss the lessons from these efforts and opportunities toward more general, scalable, and reusable AI systems for science and engineering.

Short bio: Dr. Yihui (Ray) Ren is a Senior Computational Scientist in AI/ML and the AI-Codesign Group Lead in the Artificial Intelligence Department within Brookhaven National Laboratory's Computing and Data Sciences Directorate. His research focuses on AI for Science, AI-hardware codesign, real-time AI systems, and the evaluation of emerging AI hardware architectures. He also develops advanced AI methodologies for nuclear safeguards applications. Dr. Ren's key contributions include unpaired domain mapping techniques to mitigate domain shift, generative surrogate modeling, object detection and video synthesis using event-based cameras, and the development of AI foundation models such as the Foundation Model for Nuclear and Particle Physics (FM4NPP). Prior to joining Brookhaven National Laboratory in 2018, he was a postdoctoral researcher at Virginia Tech. He received his Ph.D. in Physics from the University of Notre Dame in 2015.

Location: NCS 120

Zoom: https://stonybrook.zoom.us/j/92507585369?pwd=9bw2hsQmLbladVpPRiaWK94gYlwCGQ.1&jst=2

2026 MIC Symposium on Multilingualism | Featured Talk

Economy and Language Vitality

Abstract: In this paper I discuss some aspects of language vitality that have been overlooked in the dominant discourse on language endangerment and loss, especially the ecosystemic factors that have enabled the dominant language to prevail. These include the socioeconomic structures in which competing languages have coexisted. Globalization, national demographic size, and political power do not always explain why some languages have become extinct. One must explain the specific ecosystemic conditions in which a group has been (dis)advantaged politically and economically. Is it true that the language-shifters are ashamed of their cultural traditions and that in European colonies they have always done so to speak European languages because these are prestigious? What does the migration and contact history of mankind since the development of long-distance trade and the rise of empires tell us about language shifts and the vitality of cultures, including languages? Are Indigenous peoples the only ones who have lost their languages?

Speaker: Salikoko S. Mufwene is the Edward Carson Waller Distinguished Service Professor in the Dept. of Linguistics, the Dept. of Race, Diaspora, and Indigeneity, and the College at the University of Chicago. His research area is evolutionary linguistics, focused on the phylogenetic emergence of languages and language speciation, and on language vitality. He has authored and (co-)edited dozens of books and has published hundreds of articles, book chapters, and book reviews. He is a fellow of the Linguistic Society of America, of the American Philosophical Society, and of the American Academy of Arts and Sciences. He assumed the Chaire Mondes francophones at the Clollège de France for the 2023-24 academic year.

Faculty Response Panel:
  • S. N. Sridhar (Panel Chair; SUNY Distinguished Service Professor, Asian and Asian American Studies
    and Mattoo Center for India Studies)
  • Manisha Desai (Executive Director of Center for Changing Systems of Power; Empowerment Charitable Trust
    Endowed Professor in Global Citizenship; Professor of Sociology and Women, Gender, and Sexuality Studies,
    Senior Research Associate, United Nations Research Institute for Social Development)
  • Sara Hamideh (Associate Professor, Marine and Atmospheric Sciences)
  • Janet Ward (Professor, Philosophy; Associate Provost for Arts, Humanities, and Social Sciences Initiatives)

Location: Humanities 1006
Abstract: Anxiety disorders are characterized by persistent and excessive form of fear and worry that interferes with daily functioning, distinguishing it from the adaptive anxiety that helps individuals respond to challenges. Despite affecting millions worldwide and costing a significant public health burden, anxiety disorders still remain underdiagnosed than actual prevalence due to lack of understanding and stigmatization. Leveraging machine learning (ML) and natural language processing (NLP) approaches can help bridge this gap by enabling scalable and accessible mental health assessments, offering a data-driven understanding of anxiety from individual and societal perspectives, and shedding light on societal stigmas toward mental health conditions. At the same time, advancing ML and NLP techniques for anxiety research presents unique technical challenges, such as effectively modeling linguistic markers of anxiety and ensuring interpretability in mental health predictions.

This dissertation investigates anxiety from both individual and societal perspectives using artificial intelligence. First, we explore individual manifestations of anxiety through three methodological advancements: (1) integrating contextual and discourse-level embeddings to improve language-based anxiety prediction using Facebook posts and selfreported surveys; (2) enhancing cognitive dissonance detection in Twitter dataset with transfer learning and active learning; and (3) developing longitudinal representation learning approaches that achieve both predictive utility and interpretability of adolescent psychopathology. Finally, we extended our analysis to societal dimension of anxiety by identifying and categorizing social norms expressed in Reddit and Twitter posts and examining their associations with anxiety. By combining data-driven methods with psychological insights, this work studies anxiety from various angles - capturing both individual experiences and societal influences - offering a step toward a more comprehensive understanding of its causes and manifestations.

Speaker: Swanie Juhng

https://stonybrook.zoom.us/j/98905245099?pwd=M7rI7aNfNio281qyebEUdNPBcSiK7Y.1
Join librarian Christine Fena for an interactive workshop that invites you to explore AI tools firsthand, not just as users, but as critical investigators. Through playful experimentation and collaborative discovery, you'll uncover inherent biases, probe algorithmic flaws, and gain a deeper understanding of AI's limitations and societal impacts.

Location: Melville Library, Central Reading Room, Lab B

https://library.stonybrook.edu/library-events/critiquing-ai/
CSE 656 Seminars in Computer Vision - Wednesdays 11:30am-12:50pm, Room NCS 120

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 PhD program or (2) receive permission from the instructors.

Each seminar will consist of multiple short talks (around 10 minutes) by multiple people. Students can register for 1 credit for CSE656. Registered students must attend and present a minimum of 2 or 3 talks. Everyone else is welcome to attend. Fill in https://forms.gle/pCVXovgfMfQwGqG38 to subscribe to our mailing list for further announcement.

The first meeting will be Wed Jan 29 at 11.30am, room 120 New CS. The meeting will deal with organizational matters and we will start right away with some presentations. Send David Paredes Merino <dparedesmeri@cs.stonybrook.edu> an email if you are interested but cannot attend the first meeting. Please forward to people outside the CS department that you think might be interested.
Abstract: Large language models (LLMs) may exhibit unintended or undesirable behaviors. Recent works have concentrated on aligning LLMs to mitigate harmful outputs. Despite these efforts, some anomalies indicate that even a well-conducted alignment process can be easily circumvented, whether intentionally or accidentally. Does alignment fine-tuning yield have robust effects on models, or are its impacts merely superficial? In this work, we make the first exploration of this phenomenon from both theoretical and empirical perspectives. Empirically, we demonstrate the elasticity of post-alignment models, i.e., the tendency to revert to the behavior distribution formed during the pre-training phase upon further fine-tuning. Leveraging compression theory, we formally deduce that fine-tuning disproportionately undermines alignment relative to pre-training, potentially by orders of magnitude. We validate the presence of elasticity through experiments on models of varying types and scales. Specifically, we find that model performance declines rapidly before reverting to the pre-training distribution, after which the rate of decline drops significantly. Furthermore, we further reveal that elasticity positively correlates with the increased model size and the expansion of pre-training data. Our findings underscore the need to address the inherent elasticity of LLMs to mitigate their resistance to alignment.

Speaker: Huajian Zhang

Location: CS2311