Welcome new faculty members

August 1, 2023

The Statistics and Operations Research Department would like to welcome our newest faculty members, Assistant Professors Daniel Kessler (jointly with SDSS), Patrick Lopatto and Ali Mohammad Nezhad!

Dr. Kessler

Dr. Kessler completed his PhD in 2023 at the Department of Statistics at the University of Michigan advised by Professor Liza Levina. He is currently an NSF Postdoctoral Fellow at the University of Washington where he works with Professor Daniela Witten. His research interests include the statistical analysis of networks, post-selective inference, high-dimensional statistics, applications involving human neuroimaging, computational and cognitive neuroscience, and high-performance computing. He looks forward to joining STOR in 2024 and will also hold a joint appointment in the School of Data Science and Society.

Dr. Lopatto

Dr. Lopatto studies problems arising from causal inference, high-dimensional statistics, and random matrix theory. He also enjoys making statistics accessible and engaging for students. He received his PhD in mathematics from Harvard University in 2020. He was a postdoctoral member of the Institute for Advanced Study, and he is currently a postdoc at Brown University. Dr. Lopatto will join STOR in 2024.

Dr. Mohammad Nezhad

Dr. Mohammad Nezhad was previously a Postdoctoral Research Associate at the Carnegie Mellon University, and a Golomb Visiting Assistant Professor in the Department of Mathematics at Purdue University, mentored by Professor Saugata Basu. He received his PhD in Industrial and Systems Engineering from Lehigh University in 2018 under the supervision of Professor Tamas Terlaky. His research lies at the intersection of continuous optimization, computational complexity, and real algebraic geometry. Dr. Mohammad Nezhad has recently developed interest in computational topology and its applications to optimization and machine learning.

SDSS associate dean

July 5, 2023

Prof. Budhiraja now serves as senior associate dean for academic and faculty affairs in the School of Data Science and Society.

2023 Graduation Ceremony

May 20, 2023

Congratulations class of 2023!

The department held a graduation ceremony on Sunday May 8. The keynote speaker was Dr. Zeynep Tufekci (Craig Newmark Professor of Journalism, Columbia University & Director of the Craig Newmark Center for Journalism Ethics and Security).

This year’s cohort included 193 STAN majors, and the following graduate students:

2023 INFORMS Franz Edelman award

April 28, 2023

Our Ph.D. alumnus Minghui Liu (who graduated in 2015 and was advised by Gabor Pataki) was part of the winning team for the 2023 INFORMS Franz Edelman award for their work on “Optimizing Walmart’s Outbound Supply Chain from Strategy to Execution – A Grocery Case Study”.

Neurodegenerative disease discovery

April 28, 2023

New research uncovers link between neurogenerative disease and subcortical shape changes in the brain

A recent research led by Prof. Zhengwu Zhang from the Department of Statistics and Operations Research (STOR) at UNC-Chapel Hill uncovered how neurodegenerative diseases like Alzheimer’s can accelerate atrophy in subcortical brain regions in individuals aged 60-75, compared to the normal aging process.

Through a series of brain scans, size changes were visible in the lateral ventricle, which contains and helps circulate cerebrospinal fluid, and the hippocampus, which supports limbic system processing of emotion, memory and behavior.

These findings were published recently as a discussion paper in the Journal of American Statistics Association (JASA), one of the most prestigious statistical journals which only publishes a few discussion papers each year. In the paper, the research team introduced a new method called longitudinal elastic shape analysis (LESA) for examining changes in specific brain regions over time. This comprehensive framework consists of five key components: subcortical surface extraction, elastic shape analysis, principal components analysis (PCA) of shapes, continuous shape trajectory fitting, and shape-trajectory-on-scalar regression.

The study was a joint effort between the College of Arts and Gillings School of Global Public at UNC Chapel Hill and the Florida State University. The co-authors of the study include Zhengwu Zhang, PhD, assistant professor in STOR at UNC; Yuexuan Wu, a doctoral student in the Department of Statistics at FSU; Di Xiong, a visiting doctoral student in biostatistics at UNC; Anuj Srivastava, PhD, a professor of statistics at FSU; and two biostatistics professors, Joseph G. Ibrahim, PhD and Hongtu Zhu, PhD.

The team applied this innovative framework to study brain MRI scans of 2,275 individuals, analyzing a total of 9,628 shape surfaces. They found that the atrophy of subcortical regions begins early in life, around the age of 30, and accelerates after 60 years old. Furthermore, findings show that Alzheimer’s disease further speeds up this shrinkage in comparison to normal aging for those between 60 to 70 years old.

The LESA framework enables researchers to accurately identify shape changes on the subcortical surfaces. They discovered that atrophy of the hippocampus associated with Alzheimer’s disease primarily occurs in the back of the organ, which is where crucial parts, known as subfields CA1, CA1, CA2 and CA4, are located. In addition, both Alzheimer’s disease and genetic risk factors, specifically the presence of two genetic alleles called ApoE4, contribute to more severe atrophy of subcortical regions, such as hippocampus and lateral ventricle, during the aging process.

Kai Zhang named IMS Fellow

April 25, 2023

Professor Kai Zhang has been elected as 2023 Institute of Mathematical Statistics (IMS) Fellow. The designation of IMS Fellow has been a significant honor for over 85 years. IMS Fellowship honors the outstanding research and professional contributions of its members, contributions that help keep IMS in a leading role in the field of statistics and probability. Each Fellow has demonstrated distinction in research in statistics or probability or has demonstrated leadership that has profoundly influenced the field.

All of the new IMS Fellows will be honored at the IMS Presidential Address and Awards Ceremony at the Joint Statistical Meetings in Toronto.

Amir Dembo to deliver Hotelling Lectures

April 18, 2023

The Hotelling Lectures are an annual event in the Department of Statistics & Operations Research at the University of North Carolina – Chapel Hill, honoring the memory of Professor Harold Hotelling our first chairman. This year we are honored to have Professor Amir Dembo from Stanford University to deliver our two Hotelling lectures which are open to the public.

Biography
Amir Dembo obtained his PhD in Electrical Engineering from Technion, Israel. Since 1990, he has been on the faculty of Stanford University and since 2012 as the Marjorie Mhoon Fair Professor in Quantitative Science. His areas of specialization are probability theory and stochastic processes, information theory, large deviations, and their applications in in communication, control, and biomolecular sequence analysis. Together with Ofer Zeitouni, he has authored a book on the theory of large deviations which is now a classical reference in the field. He has served as editor of Probability Theory and Related Fields and of the Annals of Probability. He is a fellow of the Institute of Mathematical Statistics, and in 2022 was elected to the National Academy of Sciences.

Non-linear Large Deviations and Applications
Monday, April 24, 2023 (3:30-4:30pm 209 Manning Hall)
Reception following the lecture 4:30-5:30pm in the 3rd Floor lounge of Hanes Hall

I will overview the emerging theory of nonlinear large deviations, in particular for establishing the naive mean field approximation for certain Gibbs measures and its relation to the representation of such measures as mixtures of not too many product measures. Among the applications we explore, are the abundance of certain patterns in sparse random graphs, having many arithmetic progressions in a random set, and the universality of the Potts model on graphs of growing average degrees.

Sparse Random Graphs with Unusually Large Subgraph Counts
Wednesday, April 26, 2023 (3:30-4:30pm 120 Hanes Hall)
Reception prior to the lecture 3:00-3:30pm in the 3rd Floor lounge of Hanes Hall

In this talk, based on joint works with Nicholas Cook, Huy Tuan Pham and Sohom Bhattacharya, I will discuss recent developments in the study of the upper tails for counts of several fixed subgraphs in a large sparse random graph (such as Erdős–Rényi or uniformly d-regular). These results allow in turn to determine the typical structure of samples from an associated class of Gibbs measures, known as Exponential Random Graph Models, which are widely used in the analysis of social networks.

Nizenson awarded NSF graduate fellowship

April 18, 2023

Our student Michael Nizenson was awarded an NSF graduate fellowship.

The National Science Foundation’s highly competitive program supports those pursuing research-based graduate degrees. Thirty-three students at the University of North Carolina at Chapel Hill have received prestigious awards from the National Science Foundation (NSF) Graduate Research Fellowship Program (GRFP) for their research in STEM-related fields.

Read more in the Graduate School Magazine.

STOR at the UNC Science Expo

April 5, 2023

Last Saturday, April 1st, UNC held its annual Science Expo.

The STOR booth was a success! Prof. Mariana Olvera-Cravioto led the organization with support from Profs. Andrew Nobel and Zoe Huang, and the help of several graduate students:

and undergraduate STAN majors:

We prepared a variety of fun games including:

Monty Hall game

Mind reader

Galton board

Network formation game

RTG Women Luncheon: Ingrid Daubechies

April 5, 2023

Each semester the RTG program will host a luncheon for women trainees with a faculty role model, from within or outside UNC, to share and discuss unique challenges, experiences, and opportunities for women in STEM.

This semester the luncheon will be held on April 20th from 12:30pm to 2:00pm at Carolina Union (Rooms 3206AB). We will have Prof. Ingrid Daubechies from Duke University as the faculty role model joining the lunch. Daubechies is recognized for her study of the mathematical methods that enhance image-compression technology and she is dubbed the “Godmother of the Digital Image”.

Her research involves the use of automatic methods from both mathematics, technology, and biology to extract information from samples such as bones and teeth. She developed sophisticated image processing techniques used to help establish the authenticity and age of some of the world’s most famous works of art, including paintings by Vincent van Gogh and Rembrandt.

Daubechies is a member of the National Academy of Engineering, the National Academy of Sciences, and the American Academy of Arts and Sciences. Her accomplishments have garnered her the Wolf Prize, MacArthur Fellowship, NAS Mathematics Prize, Steele Prize, Nemmers Prize, among others. She is on the board of directors of Enhancing Diversity in Graduate Education (EDGE), a program that helps women entering graduate studies in the mathematical sciences. She was the first woman to be president of the International Mathematical Union (2011–2014).