Department Colloquium - Francesco Sorrentino

April 5, 2019

Cluster Synchronization in Networks with Symmetries We first review the master stability function (MSF) approach to synchronization of networks of coupled identical oscillators. The original formulation proposed by Pecora and Carroll applies to the case that all the oscillators in the network converge on the same time-evolution (complete synchronization) and...

Department Colloquium - Yunnan Yang

March 22, 2019

Optimal transport for seismic inversion: tackling the nonlinearity. Full waveform inversion (FWI) is a seismic imaging method which is now part of the conventional imaging workflow in the industry. It is also used for global and regional scale imaging in seismology. Its primary interest compared to tomography is its high-resolution...

Department Colloquium - Joshua A. Grochow

March 16, 2019

Computational Complexity, Dynamical Systems, and Non-Convex Optimization For a given computational problem, computational complexity asks the question of the resources needed - such as time, space, energy - by any algorithm which solves the problem. Despite algorithms being a form of discrete dynamical system (in both time & space), the...

Department Colloquium - Fan Yang

March 15, 2019

Using Survival Information in Truncation by Death Problems Without the Monotonicity Assumption In some randomized clinical trials, patients may die before the measurements of their outcomes. Even though randomization generates comparable treatment and control groups, the remaining survivors often differ significantly in background variables that are prognostic to the outcomes...

Department Colloquium - Nancy Rodriguez and Daniel Appelö

March 7, 2019

Nancy Rodriguez, Department of Applied Mathematics, University of Colorado Boulder "Mathematical Biology and Sociology: a Buff's Perspective" Daniel Appelö , Department of Applied Mathematics, University of Colorado Boulder “Computational Mathematics at CU Boulder”

Department Colloquium - Jan S Hesthaven

March 1, 2019

ontrolling oscillations in high-order accurate methods through neural networks While discontinuous Galerkin methods have proven themselves to be powerful computational methods, capable of accurately solving a variety of PDE's, the combination of high-order accuracy and discontinuous solutions remain a significant challenge. Traditional methods such as TVB limiting or artificial viscosity...

Department Colloquium - Maria D'Orsogna

Feb. 22, 2019

Neuroendocrine stress response and PTSD The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system that regulates numerous physiological processes. Disruptions are correlated with stress-related diseases such as PTSD and major depression. We characterize normal and diseased states of the HPA axis as basins of attraction of a dynamical system describing the...

Department Colloquium - Daphne Klosta

Feb. 15, 2019

A touch of non-linearity in fluid fields: where spheres “think” collectively and swim together From crawling cells to orca whales, swimming in nature occurs at different scales. The study of swimming across length scales can shed light onto the biological functions of natural swimmers or inspire the design of artificial...

Department Colloquium - Sebastian Skardal

Feb. 8, 2019

Practical and Theoretical Questions in Network Synchronization: Optimization and Control Collective behavior in large ensembles of network-coupled dynamical systems remains an active area of research in the nonlinear dynamics and networks science communities. Example applications stem from both naturally-occurring to man-made systems, e.g., cardiac pacemaker cells, mammalian circadian rhythms, Josephson...

Department Colloquium - Emiliano Dall'anese

Feb. 1, 2019

Feedback-based online algorithms for time-varying network optimization The talk focuses on the synthesis and analysis of online algorithmic solutions to control networked systems based on performance objectives and engineering constraints that may evolve over time. The time-varying optimization formalism is leveraged to model optimal trajectories of the networked systems, as...