## Events Search and Views Navigation

## November 2018

### Eric Marland, Chair of Math, Appalachian State University – Applied Math Seminar

Title: Valuing Uncertainty and Risk in Carbon Emissions and Climate Policy Abstract: This talk will look at the role of uncertainty and risk in climate policy. I will begin with the emissions side of carbon dynamics and some of our recent and current work related to NASA’s Carbon Monitoring System. This work is related to the spatial distribution of carbon in the atmosphere and approaches to correlate land-based emissions data with remotely sensed observations. I will then move to a brief discussion…

Find out more »### Saad Qadeer, UNC Chapel Hill – Applied Math Seminar

Title: Simulating Nonlinear Faraday Waves on a Cylinder Abstract: In 1831, Faraday observed the formation of standing waves on the surface of a vibrating fluid body. Subsequent experiments have revealed the existence of a rich tapestry of patterned states that can be accessed by varying the frequency and amplitude of the vibration and have spurred vast research in hydrodynamics and pattern formation. These include linear analyses to determine the conditions for the onset of the patterns, weakly nonlinear studies to understand pattern…

Find out more »### Giovanni Ortenzi, Department of Mathematical Sciences, University of Milano-Bicocca – Applied Mathematics Colloquium

Title: Boundary-interface interaction in fluid dynamics models Abstract: The interaction between a fluid and a solid boundary is a phenomenon not completely understood. An example is the interplay between an interface separating two fluids and the bottom of a channel: in the simplest case, when one of the two fluid is the air, the mechanism of ``drying" or ``wetting'' some regions of the boundary seems to be possible also in absence of the classical mechanisms based on surface tension or dissipation. In the…

Find out more »## January 2019

### Casey Miller, Applied Mathematics Colloquium

Title: Multiscale modeling of multiphase systems Speaker: C. T. Miller, Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, UNC-Chapel Hill Abstract: Two-fluid flow through porous medium systems occurs routinely in natural, engineered, and biological systems. While fundamental understanding is most advanced at the microscale, in order to model many systems of concern at the desired length scale, macroscale models are needed. Macroscale models treat systems in an averaged sense, where a point is the centroid of an averaging…

Find out more »## April 2019

### Ralph Smith, North Carolina State University – Applied Mathematics Colloquium

Title: Active Subspace Techniques to Construct Surrogate Models for Complex Physical and Biological Models Abstract: For many complex physical and biological models, the computational cost of high-fidelity simulation codes precludes their direct use for Bayesian model calibration and uncertainty propagation. For example, neutronics and nuclear thermal hydraulics codes can take hours to days for a single run. Furthermore, the models often have tens to thousands of inputs -- comprised of parameters, initial conditions, or boundary conditions -- many of which are unidentifiable…

Find out more »## August 2019

### Richard Rimanyi, Department of Mathematics, UNC-Chapel Hill – Applied Mathematics Colloquium

Title: Homology Abstract: The idea of homology turns up in many different areas of mathematics, in various disguises. On the occasion of its appearance in data science (under the name of "persistent homology" or "shape of data") in this talk we will explore the main underlying arguments and constructions in homology theory, with particular focus on persistent homology. The talk is aimed at mathematicians not familiar with homology (yet).

Find out more »## September 2019

### Karen Daniels, Department of Physics, NC State – Applied Mathematics Colloquium

Title: The role of force networks in static and flowing granular materials Abstract: Granular materials are inherently heterogeneous, and continuum models of properties such as the shear modulus and sound speed often fail to quantitatively capture their dynamics. This lack of understanding has serious consequences for the engineering of both geotechnical applications, and the industrial storage and handling of granular materials. One likely reason for these difficulties is that boundary stresses are transmitted via a chain-like network of strong forces. In my…

Find out more »### Quoc Tran-Dinh, Department of Statistics and Operations Research, UNC-Chapel Hill – Applied Mathematics Colloquium

Title: Smooth structures of convex functions and applications in Newton-type methods Abstract: In this talk, we demonstrate one way of exploiting smooth structures hidden in convex functions to develop optimization algorithms. Our key idea is to generalize a powerful concept so-called “self-concordance” introduced by Y. Nesterov and A. Nemirovskii to a broader class of convex functions. We show that this structure covers many applications in statistics and machine learning. Then, we develop a unified theory for designing numerical methods, especially proximal…

Find out more »## October 2019

### William Polacheck, Joint Department of Biomedical Engineering, UNC-Chapel Hill and NC State, and Department of Cell Biology and Physiology, UNC School of Medicine – Applied Mathematics Colloquium

Title: Tools for modeling the fluidic cellular microenvironment Abstract: Mechanical forces modulate biological processes across length scales. Extensive work in animal models has revealed tissue-scale forces are necessary for development, homeostasis, and multi-organ function, while studies at the cellular length scale have identified molecules and protein complexes, such as focal adhesions and adherens junctions, that respond to mechanical force. We develop experimental and computational tools to bridge these findings to understand how tissue-scale forces are experienced at the cellular and molecular level.…

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