Seminars and Colloquiums
for the week of February 16, 2009
Speakers:
Assistant Professor Husheng Li, EECS, UTK, Monday
Professor Stefan Richter, Wednesday
Professor Jerzy Dydak, Wednesday
Mr. Shiying Si, Thursday
Dr. Xingeng Liu, Thursday
Associate Professor Nikolay Brodskiy, Friday
Monday, February 16
DE & COMPUTATIONAL MATH SEMINAR
TIME: 3:35 – 4:25 p.m.
ROOM: AC113A
SPEAKER: Assistant Professor Husheng Li, EECS, UTK
TITLE: “Compressed Sensing: Pay Less, Expect the Same”
ABSTRACT: Compressed sensing is a novel and exciting research area arising in signal processing since 2006. It substantially reduces the amount of required samples to perfect recover the original signal based on the assumption of sparsity (i.e. most elements in the signal are zero while the locations of non-zero elements are unknown; most signals in
the natures are sparse under some transformation). Powerful algorithms like Basis Pursuit and Orthogonal Matching Pursuit have been proposed to efficiently recover the original signal and will be introduced in this seminar. Compressed sensing has abundant applications in image processing, sensor networks, remote sensing, medical imaging et al.
Wednesday, February 18
ANALYSIS SEMINAR
TIME: 3:35 – 4:25 p.m.
ROOM: AC 113A
SPEAKER: Professor Stefan Richter
TITLE: “Extensions and dilations of operator tuples, 3”
TOPOLOGY SEMINAR
TIME: 3:35 – 4:25 p.m.
ROOM: AC 113
SPEAKER: Professor Jerzy Dydak
TITLE: “A combinatorial approach to coarse geometry”
ABSTRACT: This is joint work with M.Cencelj, A.Vavpetic, and Z.Virk. Using ideas from shape theory we embed the coarse category of metric spaces into the category of direct sequences of simplicial complexes with bonding maps being simplicial. Two direct sequences of simplicial complexes are equivalent if one of them can be transformed to the other by contiguous factorizations of bonding maps and by taking infinite subsequences. That embedding can be realized by either Rips complexes or analogs of Roe's anti-v Cech approximations of spaces.
In that model coarse $n$-connectedness of $mathcal{K}={K_1to K_2 to ldots}$ means that for each $k$ there is $m > k$ such that the bonding map from $K_k$ to $K_m$ induces trivial homomorphisms of all homotopy groups up to and including $n$. The asymptotic dimension being at most $n$ means that for each $k$ there is $m > k$ such that the bonding map from $K_k$ to $K_m$ factors (up to contiguity) through an $n$-dimensional complex.
One can dualize the above construction and obtain a combinatorial approach to uniform structures.
Thursday, February 19
PROBABILITY SEMINAR
TIME: 12:40 p.m.
ROOM: HBB 132
SPEAKER: Mr. Shiying Si
TITLE: "Two-step variation for processes driven by fractional Brownian motion with applications in testing for jumps in the high frequency data. Part 5”
MATHEMATICS COLLOQUIUM
TIME: 3:35 – 4:25 p.m.
ROOM: HBB 102
SPEAKER: Dr. Xingeng Liu, SUNY Stony Brook
TITLE: "Computational studies for turbulent mixing and cell signaling"
ABSTRACT: Many systems in the engineering and biology involve moving interfaces or boundaries. Front tracking method is one of the most accurate and efficient computational approaches for studying such systems. A main challenge of developing front tracking algorithms is to capture the interface topological changes. In this talk I shall introduce an improved three-dimensional front tracking method and consider an application for turbulent mixing driven by Rayleigh-Taylor instability, which shows an excellent agreement with the experiments. For the second part of the talk, I will present a computational analysis of cell signaling in biology and medicine. Scaffold, a class of proteins, plays many important roles in signal transduction. Through studying various models of scaffold, I will show novel regulations induced by its spatial location and switch-like responses due to scaffold. To efficiently compute the models, we introduce a new fast numerical algorithm incorporated with adaptive mesh refinement for solving the stiff systems with spatial dynamics.
Friday, February 20
WORKSHOP ON COARSE GEOMETRY
TIME: 3:35 – 4:25 p.m.
ROOM: AC113
SPEAKER: Associate Professor Nikolay Brodskiy
TITLE: “Amenability II”
ABSTRACT: A homological approach to amenability will be discussed and related to the approaches from the previous talk.
If you are interested in giving or arranging a talk for one of our seminars or colloquiums, please review our calendar.
If you have questions, or a date you would like to confirm, please contact Dr. Steve Wise.
Week of:
Past notices:
Seminars from 2007-2008 academic year
Seminars from 2006-2007 academic year