Stony Brook University Applied Mathematics and Statistics

Speaker: Dr. Wonil Chung  Place: Online via Zoom, Zoom ID: 938 0290 9321 / Passcode: ams Time: Thu, 05/26/2022 - 16:00 About the speaker  Dr. Wonil Chung is an Assistant Professor in Statistics at Soongsil University. Before that, he was a research associate at Harvard T.H. Chan School of Public Health and received his Ph.D. degree in Biostatistics from the University of North Carolina at Chapel Hill (UNC) and MS and BS degrees in Statistics from Seoul National University. His research interests are in Biostatistics, Statistical Genetics, Big Data, Statistical Learning and Deep Learning. Abstract Although Type 2 diabetes (T2D) have been known as one of the important risk factors for the severity and mortality of COVID-19, the effect of T2D and its genetic susceptibility on COVID-19 are largely unknown. We analyzed the population-based cohort data of 459,188 individuals from UK Biobank with COVID-19 test results, individuals’ hospitalization data and death-related records during the period from March 11, 2020 to December 20, 2021. First, we investigated the association of T2D, and its genetic susceptibility with COVID-19 infection using multivariable logistic regression model. To capture overall genetic susceptibility for T2D, we computed polygenic risk scores (PRS) based on summary statistics from UK Biobank. In the multivariable logistic models, we found that the odds ratio (OR) of T2D was 1.555 (P= 3.49*10-86) and OR of PRS for T2D with one-unit (=standard deviation) increase in PRS was 1.064 (P=3.11*10-12), indicating the roles of T2D-related genetics in the pathogenesis of COVID-19 infection. Next, we performed multivariable Cox proportional hazard models to investigate the effect of T2D patients infected with COVID-19 on the survival times. The estimated survival curves and pairwise log-rank tests showed that the estimated hazard for COVID-19 infected T2D patients were 4.67 times (P=9.88*10-324) and 2.58 times (P=6.20*10-231) higher than individuals without COVID-19 infection and T2D, respectively and the hazard ratio (HR) of PRS for T2D with one-unit increase in PRS was 1.088 (P=4.76*10-14). Furthermore, we found the mortality of COVID-19 infected T2D patients was dramatically increased compared to T2D patients not infected with COVID-19 and the mortality of individuals with high genetic susceptibility for T2D was increased as well.    

Speaker: Dr. Nguyen Nang Thieu  Place: Online via Zoom, Zoom ID: 987 9649 9819 / Passcode: ams Time: Fri, 04/29/2022 - 16:00 About the speaker Dr. Thieu Nguyen graduated from the University of Limoges with Ph.D. in Applied Mathematics and graduated from Hanoi University of Science, Vietnam National University with Bachelor’s degree in Mathematics, Mechanics, and Informatics. His research interests are in Nonsmooth Dynamical Systems, Optimization, and Variational Analysis. Abstract Among many nonsmooth dynamical systems, sweeping processes have been recognized significantly for their broad applications in mechanics, physics, engineering, and social sciences. Pioneered by J. J. Moreau, sweeping processes have been studied and developed intensively in the last 50 years. In this talk, we will discuss a class of sweeping processes. Namely, we obtain solution existence theorems for perturbed sweeping processes, which are analogies to the two well-known Peano and Picard-Lindelöf theorems in ordinary differential equations. The convexity assumption on the constraint sets is weakened and replaced by a natural and effective generalization of convexity so-called prox-regularity. The results are applied to analyzing the behavior of some concrete mechanical sweeping processes.  

    Solha Park has been invited to the Department of Applied Mathematics and Statistics at Stony Brook New York campus's annual, informal celebration honoring a very select group of outstanding AMS students who have earned special recognition from AMS.  Solha has participated in the ceremony via Zoom on March 31st, 2022.  Please join us in congratulating her on her great achievement!  

Won Gu, one of our AMS master's students has received a Ph.D. offer from the Statistics Department at Penn State University with full financial support for five years, along with a fellowship in the first year.  Won Gu has graduated from Applied Mathematics and Statistics Department at SUNY Korea in Spring 2021 as a valedictorian. Won Gu continued her MS program from the AMS BS/MS Accelerated Program at SUNY Korea in Fall 2021 and this Spring 2022 will be her last semester.   Nilson Chapagain has been admitted to the Ph.D. program in Statistics from Texas A&M University, College Station. Nilson will be receiving a guaranteed stipend as a Graduate Teaching Assistant throughout the program period. He will be joining the interdisciplinary research in collaboration with the Computer Science and Statistics Department. Nilson will graduate from SUNY Korea with a Bachler's Degree in Applied Mathematics and Statistics and a minor in Computer Science in Spring 2022.    Please join us in congratulating Won Gu and Nilson on the successful beginning of their Ph.D. program!

Speaker: Dr. Il-Youp Kwak  Place: Online via Zoom, Zoom ID: 934 0110 4420 / Passcode: ams Time: Thu, 11/18/2021 - 16:00 About the speaker Dr. Il-Youp Kwak is an Assistant Professor in the Department of Applied Statistics at Chung-Ang University. Before that, he worked as a Postdoctoral Associate in the Division of Biostatistics at University of Minnesota and then worked as a Staff Engineer in Samsung Research at Seoul R&D Campus. Prof. Kwak received his PhD degree in Statistics from University of Wisconsin-Madison. His research interests are in big data, biostatistics, statistical software, and deep learning. Abstract It is becoming more convenient to collect and store data from various organizations such as corporations, governments, and academia. Yes, interest in big data and AI is higher now than ever before. Efficiently solving problems based on various types of collected data is a common interest of companies, governments, and academia, and data scientists are at the center of this. According to Glassdoor, a job site in the United States, data scientists have been selected as the best job for three consecutive years from 2016 to 2019. In this presentation, we will learn about Data Scientists - who they are, why they get so much attention, what they are doing, and how to become data scientists.    

Professor Suil O has been selected as a recipient of the NRF-NSFC core cooperation program (National Research Foundation of Korea and National Natural Science Foundation of China), funded by the Ministry of Science and ICT. He will serve as the Co-Principal Investigator for the research project “Algebraic and structural problems of graphs on surfaces” for 3 years (2021.12.01~2024.11.30).  

Speaker: Dr. Irene Kim  Place: Online via Zoom, Zoom ID: 997 6634 3524 / Passcode: 556273 Time: Thu, 10/28/2021 - 11:00 About the speaker Dr. Irene Kim graduated from the University of California at Davis with Ph.D. in Statistics and graduated from Stony Brook University with Bachelor’s degree in Mathematics. Her research interests are in Machine Learning, deep learning, representation learning, and uncertainty quantification Abstract This talk will be divided into two parts where the first part will be on my current research, and the second part will be focused on sharing my experience at Stony Brook University and studying Math/Applied Math as an undergraduate degree. PART 1: In this talk, I will take an oil reservoir modeling and a history matching problem as an example to address the challenges of modern data analysis. As modern data become more complex and higher dimensional, finding a way to represent the data in a concise and useful form is an important problem. An auto-encoder can be used to find a low dimensional representation for an oil reservoir data and used for history matching problem. PART 2: Experience at Stony Brook University as a math major, life after graduation, job interview etc.  

  A warm welcome from SBU AMS Department for SUNY Korea students!  

Professor Suil O has been selected as a recipient of the NRF-NSFC Joint Grant (National Research Foundation of Korea and National Natural Science Foundation of China), funded by the Ministry of Science and ICT. He will serve as the principal investigator for the research project “Spectral Radii of Saturated Graphs” for 2 years (2021.09.01~2023.08.31).

Hyerin Choi who is double majoring in AMS has been selected to National Institute for Mathematical Sciences as the Industrial Mathematics Undergraduate Trainee for Summer 2021. Hyerin will get the opportunity to practice solving industrial mathematics problems and experience industrial mathematics culture proliferation activities.

We are pleased to announce that Professor Young-Seon Lee from the AMS Department will offer Summer 2021 Math Boot Camp! This camp can be beneficial to students who want to improve their math skills and math placement scores prior to the Math Placement Exam. This camp also provides a brief review of mathematical concepts, which is useful to prepare for SBU math courses.  It is a first-come-first-serve basis. Do not miss this great opportunity! Please find the details about the Math Boot Camp from the poster, and if you are interested in registering for the Math Boot Camp this Summer, please feel free to contact YounJu Baek via younju.baek@sunykorea.ac.kr.  

Professor Young-Seon Lee has been selected as a recipient of the National Research Foundation research grant funded by the Ministry of Science and ICT. He will serve as a principal investigator for the research project entitled “Assessing and minimizing parameter uncertainty in mathematical models of cardiac cells” for two years and nine months (2021.06.01 ~ 2024.02.29) Professor Ky Tran has been selected as a recipient of the National Research Foundation research grant funded by the Ministry of Science and ICT. He will serve as a principal investigator for the research project entitled “Asymptotic behaviors, control, and applications of stochastic hybrid systems” for two years and nine months (2021.06.01 ~ 2024.02.29).  

Speaker: Dr. Yinfei Kong  Place: Online via Zoom. Zoom ID: 912 6831 4669, Passcode: 686304 Time: Fri, 05/14/2021 - 11:00 About the speaker Dr. Yinfei Kong is an Associate Professor at the Department of Information Systems and Decision Sciences, College of Business and Economics, California State University, Fullerton. He received his Ph.D. degree from the University of Southern California in 2016.  He is particularly interested in deep learning, big data analytics, and applications in business and health care. (Web-page: https://sites.google.com/site/yinfeikong/; Email: yikong@fullerton.edu) Abstract We operationalize an intersectionality conceptual framework using a novel statistical approach and with these efforts improve estimation of disparities in access to treatment beyond race. We analyzed a sample of 941,286 treatment episodes collected in 2015, 2016, and 2017 in the United States from the Treatment Episodes Data Survey (TEDS-A). We also analyzed a subset of TEDS data from California (N=188,637) and Maryland (N=184,276), states with the largest sample of episodes. We conducted a retrospective subgroup analysis using a two-step approach called virtual twins. In step 1, we trained a classification model that gives the probability of waiting (one day or more). In step 2, we identified the subgroups with higher probability difference of waiting due to race. We tested three classification models for step 1 and identified that random forest was the classification model for step 1. Findings suggested that the following factors can define the subgroup more vulnerable to racial disparities: services setting, referral source, living arrangement, prior episodes, medication-assisted opioid treatment, and frequency of using the primary drug.    

Speaker: Prof. Emilio Vilches  Place: Online via Zoom. Zoom ID: 518 570 2306 / Passcode: 096577 Time: Fri, 04/16/2021 - 11:00 About the speaker Emilio Vilches, Institute Engineering Sciences, Universidad de O’Higgins Abstract Differentialequations with nonsmooth componentsoccur in various situations. For example, they arise in mechanical systems if the effects of dry friction are included in the model or happen in the case of impacts. They are present in electrical circuits or biological systems if nonsmooth characteristics are used to represent switches. This seminar aims to introduce Moreau’s Sweeping Process, which is a class of nonsmooth dynamical systems involving normal cones to time-dependent moving sets. We review basic results, numerical methods, and practical applications in nonsmooth mechanics and electrical circuits. The current state of research and the main challenges will be discussed. This work has been supported by ANID-Chile under project Fondecyt de Iniciación 11180098.    

Professor Hyunwook Koh has been selected as a recipient of the National Research Foundation research grant funded by the Ministry of Science and ICT. He will serve as a principal investigator for the research project entitled "Data-driven adaptive mediation analyses for human microbiome studies" for three years (2021.3 - 2024.2).