Probability Seminar
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Posted February 24, 2018

11:00 am - 12:00 pm Lockett 239
Hui-Hsiung Kuo, Mathematics Department, LSU

Multiplicative renormalization method for orthogonal polynomials

Abstract: I will give a very simple talk to show how I discovered this method and how powerful it can be. The ideas will be introduced through concrete examples.

Applied Analysis Seminar
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Posted January 11, 2018

Last modified February 20, 2018

Wei Li, LSU

Fluorescence ultrasound modulated optical tomography in diffusive regime

Fluorescence optical tomography (FOT) is an imaging technology that localizes fluorescent targets in tissues. FOT is unstable and of poor resolution in highly scattering media, where the propagation of multiply-scattered light is governed by the smoothing diffusion equation. We study a hybrid imaging modality called fluorescent ultrasound-modulated optical tomography (fUMOT), which combines FOT with acoustic modulation to produce high-resolution images of optical properties in the diffusive regime. The principle of fUMOT is to perform multiple measurements of photon currents at the boundary as the optical properties undergo a series of perturbations by acoustic radiation, in which way internal information of the optical field is obtained. We set up a Mathematical model for ufUMOT, prove well-posedness for certain choices of parameters, and present reconstruction algorithms and numerical experiments for the well-posed cases.

Posted February 19, 2018

6:00 pm - 7:00 pm Keiser Math Lounge Room 321
Jared Braud, Starmount Life

ASA Club Meeting

Senior Actuarial student, Tia Jones will be presenting about her internship experience last summer. Jared Braud ASA, will be presenting his experience in specialty insurance on the health and life side.

Informal Topology Seminar
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Posted January 24, 2018

10:00 am - 12:00 pm Lockett 233
Federico Salmoiraghi, Department of Mathematics, LSU

TBD

Topology Seminar
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Posted November 13, 2017

3:30 pm - 4:30 pm Lockett 233
Ivan Levcovitz, CUNY Graduate Center

TBD

Applied Analysis Seminar
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Posted January 10, 2018

Last modified February 12, 2018

Masato Kimura, Kanazawa University, Japan

A phase field model for crack propagation and some applications

Colloquium
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Posted February 22, 2018

3:30 pm - 4:20 pm TBD
Wen-Ching Winnie Li, Pennsylvania State University

TBD

Computational Mathematics Seminar

Posted February 14, 2018

3:30 pm - 4:30 pm 1034 Digital Media Center
Yi Zhang, University of North Carolina at Greensboro

Numerical Approximations for a Singular Elliptic Variational Inequality

Abstract: The displacement obstacle problem of simply supported plates is an example of a fourth order variational inequality. As the bending rigidity tends to zero the problem degenerates to an elastic membrane obstacle problem which is a second order variational inequality. In this talk we will introduce C0 interior penalty methods for this singular perturbed problem with small parameter. Robust error estimates with respect to the parameter will be presented. We also discuss the convergence of numerical solutions to the unperturbed second order elliptic variational inequality. This is joint work with Susanne Brenner and Li-yeng Sung.

Algebra and Number Theory Seminar
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Posted January 15, 2018

Last modified February 22, 2018

Wen-Ching Winnie Li, Pennsylvania State University

colloquium this week

Informal Topology Seminar
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Posted January 24, 2018

10:00 am - 12:00 pm Lockett 233
Yu-Chan Chang, Louisiana State University

TBD

Topology Seminar
Seminar website

Posted October 18, 2017

3:30 pm - 4:30 pm Lockett 233
Bulent Tosun, University of Alabama

TBD

Colloquium
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Posted December 17, 2017

Last modified February 22, 2018

Habib Ouerdiane, University of Tunis El Manar

TBD

Applied Analysis Seminar
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Posted January 16, 2018

Last modified February 20, 2018

Tadele Mengesha, The University of Tennessee, Knoxville

Sobolev regularity estimates for solutions to spectral fractional elliptic equations

Abstract: Global Calderon-Zygmund type estimates are obtained for solutions to fractional elliptic problems over smooth domains. Our approach is based on the "extension problem" where the fractional elliptic operator is realized as a Dirichlet-to-Neumann map corresponding to a degenerate elliptic PDE in one more dimension. This allows the possibility of deriving estimates for solutions to the fractional elliptic equations from that of degenerate elliptic equations. We will confirm this first by obtaining weighted estimates for the gradient of solutions to a class of linear degenerate/singular elliptic problems over a bounded, possibly non-smooth, domain. The class consists of those with coefficient matrix that symmetric, nonnegative definite, and both its smallest and largest eigenvalues are proportion to a particular weight that belongs to a Muckenhoupt class. The weighted estimates are obtained under a smallness condition on the mean oscillation of the coefficients with a weight. This is a joint work with T. Phan.

Computational Mathematics Seminar

Posted January 30, 2018

Last modified February 14, 2018

Liping Wang, Nanjing University of Aeronautics and Astronautics

A Joint Matrix Minimization Approach and the Applications in Collective Face Recognition and Seismic Wavefield Recovery

Abstract: Recently, image-set based face recognition and multi trace seismic wavefield recovery have attracted extensive attention in pattern recognition and geophysical community. Representation coding is one of popular ways for both face recognition and seismic wave reconstruction. Similar representative coding pattern among the group of samples is observed both in facial images and seismic signals. To take account of the collective correlation from a given set of testing samples as well as each individual, a matrix minimization model is presented to jointly representing all the testing samples over the coding bases simultaneously. A generalized matrix norms employed to measure the interrelation of the multiple samples and the entries of each one. For solving the involved matrix optimization problem, a unified algorithm is developed and the convergence analysis is accordingly demonstrated for the range of parameters p in (0,1]. Extensive experiments on public data of facial images and real-world seismic waves exhibit the efficient performance of the joint technique over the state-of-the-art methods in recognition or recovery accuracy and computational cost.

Topology Seminar
Seminar website

Posted October 18, 2017

3:30 pm - 4:30 pm
Ina Petkova, Dartmouth College

TBD

Applied Analysis Seminar
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Posted January 10, 2018

Last modified February 5, 2018

Prashant Kumar Jha, LSU

Numerical analysis of finite element approximation of nonlocal fracture models

We discuss nonlocal fracture model and present numerical analysis of finite element approximation. The peridynamic potential considered in this work is the regularized version of the bond-based potential generally considered in peridynamic literature (Silling 2000). In the limit of vanishing nonlocality, peridynamic model behaves like a elastodynamic model away from a crack zone and has a finite fracture energy associate to crack set (Lipton 2014, 2016).Using this property we relate the parameters in a peridynamic potential with given elastic constant and fracture toughness. Before we consider finite element approximation, we show that the problem is well posed. We show the existence of evolutions in H^2 space. We consider finite element discretization in space and central difference in time to approximate the problem. Approximation is shown to converge in L^2 norm at the rate Cttriangle t+C_sh^2/s^2. Here triangle t is the size of time step, h is the mesh size, and is the size of horizon (nonlocal scale). Constants C_t and C_s are independent of h and triangle t. In the absence of nonlinearity, stability of approximation is shown. Numerical results are presented to verify the convergence rate. This is a joint work with Robert Lipton.

Algebra and Number Theory Seminar
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Posted January 16, 2018

3:10 pm - 4:00 pm
Rina Anno, Kansas State University

TBA

Informal Topology Seminar
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Posted January 24, 2018

10:00 am - 12:00 pm Lockett 233
Nurdin Takenov, Louisiana State University

TBD

Topology Seminar
Seminar website

Posted January 10, 2018

Last modified January 12, 2018

Adam Levine, Duke University

TBD

Colloquium
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Posted December 17, 2017

3:30 pm - 4:20 pm TBD
Guozhen Lu, University of Connecticut

TBD