## Faculty - Tenured/Tenure-track

Dr. Shu-Chuan 'Grace' Chen

**Professor**

Office: PS 321A

**Ph.D.: ** Statistics and Operations Research, Pennsylvania State University, 2003

**Research Interests:** Bioinformatics, high-dimensional clustering, mixture models

Dr. Chen's research mainly focuses on bioinformatics, especially in developing statistical methods and algorithms for functional genomic data. Dr. Chen's past publications involved with the development of mixture models for clustering high dimensional sequences, its related theoretical justifications and applications. She also published papers in neuron spike trend studies, data mining, analysis of election data and DNA sequences' matching probability.

Dr. Yu Chen

**Professor**

Office: PS 322D

**Ph.D.: **Mathematics, University of Notre Dame, 2002

**Research interests:** Lie theory, Representation theory

My main research interest lies in Lie theory and representation theory. Suppose that W is a Coxeter group, e.g., a finite group generated by reflections on a Euclidean space. Then W can be decomposed into a disjoint union of left cells or two-sided cells. These cell structures can be applied to construct the representations of W and the representations of the Hecke algebra of W explicitly. When W is a Weyl group or an affine Weyl group, the two-sided cells of W are also closely related to the unipotent classes in the corresponding linear algebraic group. Algebraists try to find an explicit description of the left cells and two-sided cells in each W, especially in the case when W is an affine Weyl group.

I am also interested in applied mathematics, e.g., the theory of asset pricing in mathematical finance.

**Ph.D.: **Applied Statistics, Oregon State University, 1998

**Research interests:** Applied Statistics

I am an applied statistician focused on collaboration and consulting with scientists. I often assist in data analysis when colleagues in other fields (geosciences, biology, etc.) have difficult or unusual problems. Some of the problems I have worked on recently involve meta-analysis, discriminant analysis with messy data, partial least squares (projection to latent variables), geographically weighted regression to explore spatial patterns and possible causes of prostate and breast cancer, and the use of LiDAR remote sensing to estimate landscape characteristics in semi-arid climates. When appropriate, information criteria plays a role in model selection and assessment. I intend to use the right tool for the job, so I must teach myself new techniques as needed.

I also have a continuing interest in statistics education, including statistical literacy. I am developing a collection of cases for a case-based approach to applied statistics similar to the Statistical Sleuth by Ramsey and Schafer, but aimed at the undergraduate level.

Dr. Yury Gryazin

**Professor**

Office: PS 319A

**Ph.D.: **Mathematics, Novosibirsk State university, Russia, 1996

**Research interests:** Numerical Analysis, Inverse problems for PDE, CFD.

The main research interests of Dr. Gryazin lie in the area of Numerical Analysis and Scientific Computation. More specifically, he focuses on the development of computational approaches to the solution of applied mathematical problems arising from wide range of applications including computational electromagnetics, medical imaging, inverse problems, computational fluid dynamics, and computational finance. The results of his research recently appearing in internationally recognized publications were related to Krylov subspace based numerical methods for large sparse nonsymmetric algebraic systems and regularized stochastic optimization algorithms in risk portfolio management.

**Ph.D.: **Mathematics, Steklov Mathematical Institute, Russia, 1985

**Research Interests: **Mathematical biology, Probability and stochastic processes, Statistics, Mathematical oncology, Radiation biology, Mathematical methods in heat transfer.

The main focus of my current research is mathematical modeling and solving associated statistical problems in biomedical sciences including cell biology, molecular biology, biochemistry, radiation biology, bioinformatics, cancer biology and epidemiology, and clinical oncology. The mathematical basis of this work is probability models, stochastic processes and differential equations. I am also working on mathematical problems of heat transfer.

**Ph.D.: **Mathematics, University of Michigan, 1995

**Research interests:** Representation theory, Hecke algebras, Lie theory.

My research concerns algebras and graphs related to groups generated by reflections of a vector space. Recent research projects involve deformation algebras for symmetric groups, as well as Cayley graphs of complex reflection groups, specifically their spectra (eigenvalues) and traversability (paths and cycles). Past research has involved Hecke algebras for noncrystallographic real reflection groups, their representations, and related hyperplane arrangements.

*If you are a student interested in research opportunities, come ask about possible projects in graph theory or algebra. *

**Ph.D.: **Mathematics, Stanford University, 1986

**Research interests:** Differential geometry, Calculus of variations

My research involves applications of variational calculus to problems in differential geometry. The shape of surface interfaces is found by minimizing a certain surface energy. We are particularly interested in anisotropic interfacial energies. This means that the energy depends on the direction of the surface, as in a crystal.

**Ph.D.: **Mathematics, University of Michigan, 1995

**Research interests:** Lie groups, geometry, and dynamical systems

Dr. Payne's research is on geometric and dynamical problems related to Lie groups and Lie algebras. Recently she has been interested in the Ricci flow for homogeneous spaces, soliton metrics on nilpotent Lie algebras, and Anosov maps on nilmanifolds.

**Ph.D.: **Mathematics, Auburn University, 2014

**Research interests:** Integro-differential equations, dynamical systems and their applications in biology and ecology.

Recent research projects involve the differential equations with nonlocal diffusion operators, which can be considered as a nonlocal analog of the classical diffusion operators (the Laplacian operator). Among others, I'm interested in establishing results for nonlocal differential equations analogous to those of classical differential equations from the perspectives of spectral theory (eigenvalue problems), symptotic dynamics (long time behaviors), as well as applications to population models.

There are some undergoing research projects for undergraduates. Analyze the ordinary differential equation from the geometric point of view and use MATLAB or other techniques to illustrate the asymptotic behavior of solutions qualitatively. There are a variety of applications in Engineering, Chemistry, Physics, and many other scientific subjects. For example, the bifurcation of a system when some control parameters are changing, and the steady state of a system when the time goes to infinity.

**Ph.D.: **Mathematics, Iowa State University, 2002

**Research interests:** Scientific computing

Numerical solutions of differential equations and optimal control problems with partial differential equation constraints. Particularly interested in phase field approaches to optimal control problems.

Dr. Yunrong Zhu

**Professor
**

Office: PS 328B

**Ph.D.: **Mathematics, Pennsylvania State University, 2008

**Research interests:**

My research is in the numerical solution of linear and nonlinear partial equations, especially the finite element methods and the related efficient multilevel linear solvers. My earlier works are mainly on developing efficient multilevel solvers for the linear systems arising from the finite element approximation of the diffusion equations, Maxwell's equations, etc. in heterogeneous media. My recent research focuses more on developing various types of finite element methods (discontinuous Galerkin, weak Galerkin, virtual element, etc.) for a large class of nonlinear partial differential equations, as well as developing the related efficient solution methods.