Skip to main content
College of Sciences
Department of Mathematics

Events

Events Search and Views Navigation

Event Views Navigation

Filters

Changing any of the form inputs will cause the list of events to refresh with the filtered results.

Today

Chris Tralie, Duke University, From Musical Rhythms To Vibrating Vocal Folds: Geometric (Quasi)Periodicity Quantification in Multimedia Time Series

SAS 4201

A large variety of multimedia data inference problems require analysis of repeated structures.  In audio, for instance, the rhythm, or ``pulse'' of the music, occurs in a periodic pattern, and understanding this pattern is an important preprocessing step in music information retrieval.  In medical video analysis, there is interest in determining heart pulse rate in…

Kristen Boyle, NC State, On derivations of Leibniz algebras

Leibniz algebras are a generalization of Lie algebras. In this talk I will discuss some results on characteristic ideals, which are analogs of known results from Lie algebra. I will use these results to prove that the radical of a Leibniz algebra is a characteristic ideal. We will also explore the derivation algebra of cyclic…

Garrett Nieddu, Montclair State University, Rare Events in Stochastic Population Models

Cox 306

Noise can play a critical role in a wide array of physical and biological dynamical systems. The noise may be internal or external to the system. Internal noise is intrinsic to the system itself, and in stochastic population models, arises due to the random interactions of discrete agents in the system. On the other hand,…

Joshua Hallam, Wake Forest University, Whitney duals of graded partially ordered sets

SAS 4201

To each graded poset one can associate two sequences of numbers; the Whitney numbers of the first kind and the Whitney numbers of the second kind. One sequence keeps track of the Möbius function at each rank level and other keeps track of the number of elements at each rank level. We say two posets…

Murthy Gudatti, NC State, Efficient Forward and Inverse Algorithms for Guided Wave Inversion

SAS 4201

Guided waves are widely utilized in the fields of nondestructive testing and geophysical inversion, to estimate the medium properties through inversion of the dispersion curves. In this talk, we present improved methodologies for computing both dispersion curves and their derivatives, the two main ingredients of guided wave inversion. Specifically, a novel discretization approach based on Pade Approximants, named complex-length finite element…

The Storm Next Time: Hurricanes and Climate Change

Genome Sciences Building, G100 Auditorium at UNC Chapel Hill

" The recent tragedies of Hurricanes Harvey and Irma, together with earlier extreme events such as Hurricanes Katrina and Sandy, has raised the question whether the apparent increasing severity of such events can be attributed to the human influence on greenhouse gas warming. Dr. Emanuel will review the growing consensus that the incidence of the…

Sercan Yildiz, SAMSI,Polynomial Optimization with Sums-of-Squares Interpolants

Sums-of-squares certificates define a hierarchy of relaxations for polynomial optimization problems which are parametrized with the degree of the polynomials in the sums-of-squares representation. Each level of the hierarchy generates a lower bound on the true optimal value, which can be computed in polynomial time via semidefinite programming, and these lower bounds converge to the…

Ronghua Pan, Georgia Institute of Technology, Global regularity v.s. finite time blowup for compressible Euler equations

SAS 4201

As one of the oldest nonlinear PDE systems, the compressible Euler equations has been studied by many outstanding mathematicians. However, some basic questions, such as the global existence of classical solution v.s. finite time blowup, are still open even in one space dimension. In this lecture, we will report our recent progress in this direction, including a complete understanding on…

Missy Gaddy, NC State, SIAM Tutorial Series: Nonlinear Optimization Basics

SAS 1218

This tutorial will provide an introduction to nonlinear optimization. We will begin by presenting a general constrained nonlinear program, defining concepts like local versus global optimality, and examining the differences between convex and nonconvex problems. We will then present the Karush-Kuhn-Tucker optimality conditions. Students who have taken OR 706 (Nonlinear Programming) will find this tutorial…

Vladimir Baranovsky, UC Irvine, Chromatic graph homology for brace algebras

SAS 4201

Earlier Helme Guizon and Rong have defined chromatic graph homology complex for a graded commutative algebra, and it is easy to extend the definition to graded commutative DG algebra. One of important applications, considered earlier in our joint work with Radmila Sazdanovic, is to the case of an algebra computing cohomology of a manifold, such…

Jane Coons, NC State

Algebraic geometry and combinatorics play an important role in the analysis of phylogenetic models. I will give a brief overview of toric geometry. Then I will introduce a particular phylogenetic model, called the Cavander-Farris-Neyman model with a molecular clock, and I will discuss how we can study this model from the point of view of…

Tim David, University of Canterbury, NZ, The Dynamics of Coupled Cells: From the Discrete to the Continuous

Cox 306

Why do atherosclerotic plaques only occur at specific sites in the arteries? Does the surface geometry of the brain affect the way waves move through the cortex? These questions and many others in the physiological sphere contain implicitly a real difficulty for modellers. How do we contend with the multiple scale lengths. Plaques are quite large compared to cells making…

H. Sebastian Heese, Poole College of Management, NC State, Effects of Assortment Breadth Announcements on Manufacturer Competition

Daniels 218

Retailers typically use assortment planning to maximize store profits given product characteristics. We study the manufacturers' price-setting interactions and how these can be manipulated by the retailer's assortment strategy. We show that constraining the breadth of the assortment has two main effects on retailer profits: first, a larger assortment may intensify competitive pressure and decrease…

Casey Diekman, New Jersey Inst. Tech., Circadian regulation of gene expression and electrical activity in neurons and cardiomyocytes

Cox 306

Circadian (~24-hour) rhythms offer one of the clearest examples of the interplay between different levels of nervous system organization, with dynamic changes in gene expression leading to daily rhythms in neural activity, physiology, and behavior. The main output signal of the master circadian clock in mammals has long been believed to be a simple day/night…

Liam Watson, Universite de Sherbrooke, Modules from Heegaard Floer theory as curves in a punctured torus

Heegaard Floer theory is a suite of invariants for studying low-dimensional manifolds. In the case of punctured torus, for instance, this theory constructs a particular algebra. And, the invariants associated with three-manifolds having (marked) torus boundary are differential modules over this algebra. This is structurally very satisfying, as it translates topological objects into concrete algebraic…

Tim David, University of Canterbury, SIAM Guest Tutorial: Homogenisation and waves in tissue media

Mann 301

Investigating through mathematical modelling the complex chemistry in cells has grown in the research community over the past ten years. However trying to understand the relationship between cellular (microscale) and larger scale lengths such as the vasculature upstream of the capillary bed has proved a more difficult task. The tutorial (if you want to call…

Marco Mazzola, Université Pierre et Marie Curie,Necessary optimality conditions for infinite dimensional state constrained control problems

SAS 4201

Semilinear control systems in infinite dimensional Banach spaces are the natural framework for the description of several control problems governed by PDEs. In many models, some constraints for the state of the system may be present. In this talk, a Mayer problem associated to such systems will be discussed. In particular, a simple proof of…

Faye Pasley, NC State, Invariance and and the Numerical Range

The numerical range has been studied extensively in linear algebra and analysis. We will define and discuss properties of the numerical range, then show every numerical range invariant under rotation is associated with a matrix with nice structure.