August 12, 2020

Fredericksburg-area health officials say ‘worst is probably still ahead of us’ (Fredericksburg.com)

Lee Assists Fredericksburg-Area Health Officials with Charts of Local COVID-19 Cases

Associate Professor of Mathematics Leo Lee

Associate Professor of Mathematics Leo Lee

An article in The Free Lance-Star, “Fredericksburg-area health officials say ‘worst is probably still ahead of us’,” mentioned the contributions of Associate Professor of Mathematics Leo Lee, who is working with Dr. Donald Stern, acting director of Rappahannock Area Health District, to develop charts that show “the true number of new cases” locally. Health experts in Virginia have said we still have yet to see the peak and are projecting even higher numbers of diagnoses in the coming weeks. Read more.

2019 Graduate Emily MacIndoe’s Research Published in Mathematics Journal

A research article “Analytical Solutions of the Susceptible-Infected-Virus (SIV) Model” by Emily MacIndoe (’19) has been published in SIAM Undergraduate Research Online Journal. McIndoe’s research was completed as part of her honors requirement in the spring of 2019, and she was advised by Associate Professor of Mathematics Jangwoon “Leo” Lee. “It is highly unusual for a student to publish a paper in mathematics,” said College of Arts and Sciences Dean Keith Mellinger, who praised MacIndoe’s work and wished her “a hearty congratulations.” McIndoe’s paper is accessible through the following link on the Society for Industrial and Applied Mathematics website: https://www.siam.org/Publications/SIURO/Volume-12.

Abstract: The Susceptible-Infected-Virus (SIV) model is a compartmental model to describe within-host dynamics of a viral infection. We apply the SIV model to the human immunodeficiency virus (HIV); in particular, we present analytical solutions to two versions of the model. The first version includes only terms related to the susceptible cell-virus particle interaction and virus production, while the second includes those terms in addition to the infected cell death rate. An analytical solution, although more challenging and time-consuming than numerical methods, has the advantage of giving exact, rather than approximate, results. These results contribute to our understanding of virus dynamics and could be used to develop better treatment options. The approach used to solve each model involved first isolating one of the dependent variables, that is, deriving an equation that involves only one of the variables and its derivatives. Next, various substitutions were used to bring the equation to a more easily solvable form. For the first model, an exact solution is obtained in the form of an implicit equation. For the second model, we give an analytical solution generated by an iterative method.

Mathematics Faculty Participate in Joint Mathematics Meetings

Eight members of the Department of Mathematics presented at the annual Joint Mathematics Meetings in Atlanta in January.  The JMM is the largest mathematics conference in the country, with registrations this year exceeding 6,000 participants.  Highlights of the meeting include:

  • Randall Helmstutler, chair and associate professor, presented the talk “Generalized dihedral groups in non-commutative cryptographic protocols,” based on research conducted with former student Chris Lloyd. Dr. Helmstutler also participated in a day-long workshop for mathematics department chairs.
  • Professor Debra Hydorn presented the talk “Small Teaching” in the MAA session on discrete mathematics in the undergraduate curriculum. Dr. Hydorn also exhibited two pieces in the Mathematical Art Exhibition and participated in several committee meetings.
  • Associate professor Leo Lee gave the presentation “DDM for SPDE” in the AMS contributed paper session on numerical analysis and computer science.
  • Professor Larry Lehman gave two talks on his research in number theory, “A Continued Fraction Algorithm for Quadratic Numbers, Forms, and  Ideals” and “A Formula for the Number of Solutions of an Arbitrary Quadratic Congruence.”
  • Lecturer Jennifer Magee presented the talk “Cryptology for first-year students” in the MAA session on cryptology for undergraduates, providing an overview of the department’s unique FSEM course in the field.
  • Professor Keith Mellinger delivered “The ingredients for a successful liberal arts course in quantitative reasoning,” a talk addressing the department’s innovative approach to a recently developed course offering, Math 120: Quantitative Reasoning for the Sciences.
  • Professor Marie Sheckels presented “Enhancing Quantitative Reasoning and Skills through Exploring Scientific Applications” in the session Innovative Strategies to Inspire and Prepare Potential STEM Majors.
  • Professor Suzanne Sumner gave the talk “Environmental Applications: Introduction to Mathematical Modeling” in the session Meaningful Modeling in the First Two Years of College.

Lee Publishes Research Article in KSIAM

Associate Professor of Mathematics Leo Lee saw the recent publication of his paper “The h x p Finite Element Method for Optimal Control Problems Constrained by Stochastic Elliptic PDEs” in the Journal of the Korean Society for Industrial and Applied Mathematics.  Dr. Lee presented a talk on the results of this article at the Joint Mathematics Meetings in Seattle in January.

Leo Lee Active on Sabbatical in Korea

During his semester sabbatical leave, Associate Professor of Mathematics Leo Lee has served as visiting professor at Sogang University in Seoul, Korea, teaching courses in computational and applied mathematics for both undergraduate and graduate students.  Dr. Lee has also given several research talks on stochastic partial differential equations at Yonsei University and Sogang University and recently published the paper “An Optimization Based Domain Decomposition Method for PDEs with Random Inputs” in the journal Computers & Mathematics with Applications.  In addition, Dr. Lee has served as the symposium chair for mathematics and statistics for the US-Korea Conference 2015.

Leo Lee Presents at Joint Mathematics Meetings

Professor  Jangwoon “Leo” Lee presented his latest research at the annual Joint Mathematics Meetings in January, held this year in Baltimore.   Dr. Lee’s talk was titled “An Optimization Based Domain Decomposition Method for PDEs with Random Inputs.”

Mathematics Students Present at Joint Mathematics Meetings, Lawhorne Earns Recognition

In January three mathematics majors presented their research at the annual AMS-MAA Joint Mathematics Meetings in Baltimore, Md., which is the largest mathematics conference in the world. Kim Hildebrand presented “Using Independent Bernoulli Random Variables to Model Gender Hiring Practices” (advisor:  Dr. Debra Hydorn), Casey Howren presented “A Numerical Analysis of the SIR Model for Modeling Epidemics” (advisor:  Dr. Leo Lee), and Dane Lawhorne presented “The Fundamental Groups of the Digital Line and Circles” (advisor:  Dr. Randall Helmstutler). The students presented as part of the MAA’s undergraduate student poster session, and Dane Lawhorne was given special recognition as an outstanding presenter in the session.

Leo Lee Presents at US-Korea Conference

Assistant Professor of Mathematics, Jangwoon “Leo” Lee, recently presented “Domain Decomposition Methods for Solving Stochastic PDEs” at the annual US-Korea Conference (UKC 2013) in New Jersey.  In addition to attending many research talks at the conference, Dr. Lee chaired an applied mathematics session.

Leo Lee Presents Research at Regional Conference

Assistant Professor of Mathematics, Jangwoon “Leo” Lee, traveled to Iowa State University in Ames, Iowa, last weekend to deliver an invited talk at the Spring Central Sectional Meeting of the American Mathematical Society. His talk was titled Discretization of Stochastic Optimal Control Problems by the h x p Version of the Stochastic Galerkin FEM.