Thursday, August 31, 2017 - 15:05 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Po-Ling Loh – University of Wisconsin-Madison
We discuss two recent results concerning disease modeling on networks. The infection is assumed to spread via contagion (e.g., transmission over the edges of an underlying network). In the first scenario, we observe the infection status of individuals at a particular time instance and the goal is to identify a confidence set of nodes that contain the source of the infection with high probability. We show that when the underlying graph is a tree with certain regularity properties and the structure of the graph is known, confidence sets may be constructed with cardinality independent of the size of the infection set. In the scenario, the goal is to infer the network structure of the underlying graph based on knowledge of the infected individuals. We develop a hypothesis test based on permutation testing, and describe a sufficient condition for the validity of the hypothesis test based on automorphism groups of the graphs involved in the hypothesis test. This is joint work with Justin Khim (UPenn).
Friday, August 25, 2017 - 13:55 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Prof. Song Li – Zhejiang University
In this talk, i shall provide some optimal PIR bounds, which confirmed a conjecture on optimal RIP bound. Furtheremore, i shall also investigate some results on signals recovery with redundant dictionaries, which are also related to statistics and sparse representation.
Wednesday, August 23, 2017 - 14:05 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Joey Iverson – University of Maryland
Abstract: Shift-invariant (SI) spaces play a prominent role in the study
of wavelets, Gabor systems, and other group frames. Working in the
setting of LCA groups, we use a variant of the Zak transform to classify
SI spaces, and to simultaneously
describe families of vectors whose shifts form frames for the SI spaces
they generate.
Tuesday, August 22, 2017 - 11:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Juliette Bavard – University of Chicago
The mapping class group of the plane minus a Cantor set naturally appears in many dynamical contexts, including group actions on surfaces, the study of groups of homeomorphisms on a Cantor set, and complex dynamics. In this talk, I will present the 'ray graph', which is a Gromov-hyperbolic graph on which this big mapping class group acts by isometries (it is an equivalent of the curve graph for this surface of infinite topological type). If time allows, I will give a description of the Gromov-boundary of the ray graph in terms of long rays in the plane minus a Cantor set. This involves joint work with Alden Walker.
Thursday, August 17, 2017 - 09:00 for 8 hours (full day)
Location
Klaus 2447
Speaker
Various Speaker – Different units of GT
The workshop will launch the thematic semesters on Dynamics (Fall 2017) and Control (Spring 2018) for GT-MAP activities.
This is a two-day workshop, the first day focusing on the theme of
Dynamics, and the second day focusing on the theme of Control. There
will be light refreshments throughout the event.
The workshop will be held in the Klaus building Room 2447. More information at http://gtmap.gatech.edu/events/gt-map-workshop-dynamics-and-control
Monday, August 14, 2017 - 14:11 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Albert Fathi – Georgia Tech
We will give different topological very simple statements that seem not to have been noticed, although they are of the level
of Brouwer’s fixed point theorem. The main result is: Let F be a compact subset of the manifold M. Assume g:F->M is a continuous map which is the identity on the boundary (or frontier) of F, then the image g(F) contains either F or M\F.