Seminars and Colloquia by Series

Georgia Scientific Computing Symposium

Series
Other Talks
Time
Saturday, February 20, 2016 - 09:00 for 8 hours (full day)
Location
Mathematics and Science Center, Emory University
Speaker
variousvarious
The Georgia Scientific Computing Symposium (GSCS) is a forum for professors, postdocs, graduate students and other researchers in Georgia to meet in an informal setting, to exchange ideas, and to highlight local scientific computing research. The symposium has been held every year since 2009 and is open to the entire research community. This year, the symposium will be held at Emory University. The format of the day-long symposium is a set of invited presentations, poster sessions and a poster blitz, and plenty of time to network with other attendees. Invited speakers include: Michele Benzi, Mathematics and Computer Science, Emory University; Steven Hamilton, Radiation Transport Group, Oak Ridge National Laboratory; Alexandra Smirnova, Mathematics and Statistics, Georgia State University; Phanish Suryanarayana, School of Civil & Environmental Engineering, Georgia Institute of Technology; Molei Tao, Mathematics, Georgia Institute of Technology; Qing Zhang, Mathematics, University of Georgia. Poster sessions will be held during the lunch and afternoon breaks.

The Driverless Car Revolution

Series
Other Talks
Time
Thursday, February 18, 2016 - 13:30 for 1.5 hours (actually 80 minutes)
Location
John and Joyce Caddell Building Flex Space
Speaker
S. Rutt BridgesGeorgia Tech, Geosciences, Alumni

Convergence of gradient flows and scaling limit for particle systems

Series
Other Talks
Time
Wednesday, February 17, 2016 - 13:05 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Max FathiDepartment of Mathematics, UC Berkeley
In this talk, I will explain how the gradient flow structure of reversible Markov chains (that was discovered by Maas and Mielke independently in 2011) and the Sandier-Serfaty approach to convergence of gradient flows can be combined to study scaling limits for interacting particle systems on lattices. The exposition will be focused on the case of the simple exclusion process on the discrete torus. Joint work with Marielle Simon (INRIA Lille).

Oral exam

Series
Other Talks
Time
Monday, February 15, 2016 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 270
Speaker
John DeverGa. Tech
Topics: local Hausdorff dimension, local Hausdorff measure, diffusion on compact metric spaces, prospective further research.

Joseph Ford Commemorative Colloquium - Synchronization in Populations of Chemical Oscillators - Quorum Sensing, Phase Clusters and Chimera

Series
Other Talks
Time
Monday, November 30, 2015 - 15:05 for 1 hour (actually 50 minutes)
Location
Howey L3
Speaker
Kenneth ShowalterWest Virginia University

Please Note: Hosted by Roman Grigoriev, School of Physics

We have studied large, heterogeneous populations of discrete chemical oscillators (~100,000) to characterize two different types of density-dependent transitions to synchronized behavior, a gradual Kuramoto synchronization and a sudden quorum sensing synchronization. We also describe the formation of phase clusters, where each cluster has the same frequency but is phase shifted with respect to other clusters, giving rise to a global signal that is more complex than that of the individual oscillators. Finally, we describe experimental and modeling studies of chimera states and their relation to other synchronization states in populations of coupled chemical oscillators.

Entropy power inequality for Renyi entropy

Series
Other Talks
Time
Monday, November 23, 2015 - 11:05 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Sergey BobkovUniversity of Minnesota, Minneapolis
We will discuss an extension of the entropy power inequality in terms of the Renyi entropy to sums of independent random vectors (with densities). Joint work with G. Chistyakov.

ALS - Coloring and girth

Series
Other Talks
Time
Sunday, November 15, 2015 - 09:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Noga AlonTel Aviv University and IAS, Princeton

Please Note: Second featured lecture in the Atlanta Lecture Series in Combinatorics and Graph Theory mini-conference

The study of graphs with high girth and high chromatic number had a profound influence on the history of Combinatrics and Graph Theory, and led to the development of sophisticated methods involving tools from probability, topology, number theory, algebra and combinatorics. I will discuss the topic focusing on a recent new explicit construction of graphs (and hypergraphs) of high girth and high chromatic number, in joint work with Kostochka, Reiniger, West and Zhu.

ALS - Non-constructive combinatorics

Series
Other Talks
Time
Saturday, November 14, 2015 - 13:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Noga AlonTel Aviv University and IAS, Princeton

Please Note: First featured lecture in the Atlanta Lecture Series in Combinatorics and Graph Theory mini-conference

I will describe several old and new applications of topological and algebraic methods in the derivation of combinatorial results. In all of them the proofs provide no efficient solutions for the corresponding algorithmic problems.

Calculation of a Power Price Equilibrium under Risk Averse Trading

Series
Other Talks
Time
Monday, October 26, 2015 - 13:30 for 1 hour (actually 50 minutes)
Location
Skiles 168
Speaker
Raphael HauserMathematical Institute, University of Oxford
We propose a term structure power price model that, in contrast to widely accepted no-arbitrage based approaches, accounts for the non-storable nature of power. It belongs to a class of equilibrium game theoretic models with players divided into producers and consumers. The consumers' goal is to maximize a mean-variance utility function subject to satisfying an inelastic demand of their own clients (e.g households, businesses etc.) to whom they sell the power. The producers, who own a portfolio of power plants each defined by a running fuel (e.g. gas, coal, oil...) and physical characteristics (e.g. efficiency, capacity, ramp up/down times...), similarly, seek to maximize a mean-variance utility function consisting of power, fuel, and emission prices subject to production constraints. Our goal is to determine the term structure of the power price at which production matches consumption. We show that in such a setting the equilibrium price exists and discuss the conditions for its uniqueness. The model is then extended to account for transaction costs and liquidity considerations in actual trading. Our numerical simulations examine the properties of the term structure and its dependence on various model parameters. We then further extend the model to account for the startup costs of power plants. In contrast to other approaches presented in the literature, we incorporate the startup costs in a mathematically rigorous manner without relying on ad hoc heuristics. Through numerical simulations applied to the entire UK power grid, we demonstrate that the inclusion of startup costs is necessary for the modeling of electricity prices in realistic power systems. Numerical results show that startup costs make electricity prices very spiky. In a final refinement of the model, we include a grid operator responsible for managing the grid. Numerical simulations demonstrate that robust decision making of the grid operator can significantly decrease the number and severity of spikes in the electricity price and improve the reliability of the power grid.

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