Stats, Optimization, and Machine Learning Seminar - Jeffrey Hokanson

Oct. 16, 2018

Exploiting Low-Dimensional Structure in Optimization Under Uncertainty In computational science, optimization under uncertainty (OUU) provides a new methodology for building designs reliable under a variety of conditions with improved efficiency over a traditional, safety factor based approach. However, the resulting optimization problems can be challenging. For example, chance constraints bounding...

Nonlinear Waves Seminar - Scott Strong

Oct. 16, 2018

Geometric Quantum Hydrodynamics and the Evolution of Vortex Lines he simplest manifestation of a circulatory field occurs when a vortex line breaks the simple connectivity of an otherwise irrotational fluid. Arnold's program tells us that the evolution of such a vortex is Hamiltonian with respect to the arclength. The simplest...

APPM Colloquium - Bengt Fornberg

Oct. 12, 2018

Improving the accuracy of the trapezoidal rule The trapezoidal rule uses function values at equispaced nodes. It is very accurate for integrals over periodic intervals, but is usually quite inaccurate in non-periodic cases. Commonly used improvements, such as Simpson’s rule and the Newton-Cotes formulas, are not much (if at all)...

Complex/Dynamical Systems Seminar - Nicholas Barendregt

Oct. 11, 2018

Nicholas Barendregt, Department of Applied Mathematics, University of Colorado Boulder Heteroclinic Cycling and Extinction in Winnerless Competition Models with Demographic Stochasticity The winnerless competition formulated by May and Leonard gives a deterministic way to model populations that interact in a rock-paper-scissors style of dominance. However, when applying this and other...

Stats, Optimization, and Machine Learning Seminar - Nishant Mehta

Oct. 9, 2018

Fast Rates for Unbounded Losses: from ERM to Generalized Bayes I will present new excess risk bounds for randomized and deterministic estimators, discarding boundedness assumptions to handle general unbounded loss functions like log loss and squared loss under heavy tails. These bounds have a PAC-Bayesian flavor in both derivation and...

Nonlinear Waves Seminar - Gavriil Shchedrin

Oct. 9, 2018

A path from fractional Schrödinger equation to design and discovery of novel quantum materials Transport phenomena in multi-scale classical systems, such as disordered media, porous materials, and turbulent fluids, are characterized by multiple spatial and temporal scales, nonlocality, fractional geometry, and non-Gaussian statistics. Transport in multi-scale classical materials is described...

APPM Colloquium - Dan Massey

Oct. 5, 2018

Dan Massey, Interdisciplinary Telecom Program, University of Colorado Boulder Cybersecurity Rule 6: Use Cryptography Correctly This talk explores some of the key mathematical concepts used in cybersecurity. Cryptography is one obvious example where mathematics plays a critical role in cybersecurity. However, this talk is not centered around developing new cryptographic...

Complex/Dynamical Systems Seminar - Paul Constantine

Oct. 4, 2018

Do global sensitivity metrics for parameterized dynamical systems admit their own dynamical systems? Continuous time dynamical systems in applications include input parameters (rate constants, forcings, etc.) that must be set using measurement data. The calibration process introduces error in the fitted parameters. Part of assessing the effects of parameter error...

Geophysical/Astrophysical Fluid Dynamics Seminar - Jhett Bordwell and Ryan Orvedahl

Oct. 2, 2018

Jhett Bordwell - Chemical Transport in Giant Planets and Brown Dwarfs Abstract Pending Ryan Orvedahl - Polarity Reversals in Stars and Planets Abstract Pending

Stats, Optimization, and Machine Learning Seminar - Jed Brown

Oct. 2, 2018

Fast Algorithms and Community Software for Physical Prediction, Inference, and Design Physically-based computational models are the foundation of modern science and engineering, providing the only path to reliable prediction and inference in the presence of sparse and indirect observations as well as deeper understanding of interacting physical processes and scales...