**Seminars and Colloquiums
for 2010-2011
Week of March 21, 2011**

**Speaker:
**Prof. Steffen Rohde, University of Washington, Monday --CANCELED

Matt Bailey, Tuesday

Professor Dongbin Xiu, Purdue, Tuesday

Mr. Nick Gewecke, Tuesday

Professor Seddik Djouadi, EECS Department, UTK, Wednesday

Professor Carl Sundberg, Wednesday

Prof. Mike Langston, EECS Department, UTK, Thursday

### If you are interested in giving or arranging a talk for one of our seminars or colloquiums,

### 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. Fernando Schwartz.

**Monday, March 21**

COLLOQUIUM -- CANCELED

TIME: 3:35 - 4:25 p.m.

ROOM: Ayres 114

SPEAKER: Prof. Steffen Rohde, University of Washington

TITLE: "Random curves and random maps"

ABSTRACT: How does a path of length n on the two dimensional square lattice Z^2, chosen uniformly

at random among all such paths, look like? How does it look if the path is required to have no self-

intersections? The last decade has seen tremendous progress towards understanding a variety of

lattice processes, largely due to Oded Schramm's Stochastic Loewner Evolution SLE and the use of

conformal mappings. In this talk, aimed at the non-specialist, I will describe some highlights of this

theory. I will also address recent developments related to random planar maps (such as triangulations

of the sphere), and will discuss open questions. Title: Random curves and random maps

Abstract: How does a path of length n on the two dimensional square lattice Z^2, chosen uniformly at

random among all such paths, look like? How does it look if the path is required to have no self-

intersections? The last decade has seen tremendous progress towards understanding a variety of

lattice processes, largely due to Oded Schramm's Stochastic Loewner Evolution SLE and the use of

conformal mappings. In this talk, aimed at the non-specialist, I will describe some highlights of this

theory. I will also address recent developments related to random planar maps (such as triangulations

of the sphere), and will discuss open questions.

** Tuesday, March 22**

MATH BIOLOGY SEMINAR

TIME: 9:45 - 10:35 a.m.

ROOM: NIMBioS Classroom

SPEAKER: Matt Bailey

TITLE: "Biological Applications of Continuous Markov Chains"

COLLOQUIUM

TIME: 10:00 - 10:50 a.m.

ROOM: Ayres 405

SPEAKER: Professor Dongbin Xiu

TITLE: "Uncertainty Analysis for Complex Systems: Algorithms beyond Polynomial Chaos"

ABSTRACT: The field of uncertainty quantification has received increasing amount of attention
recently. Extensive research efforts have been devoted to it and many novel numerical techniques have
been developed. These techniques aim to conduct stochastic simulations for large-scale complex
systems. In this talk we will review one of the most widely approaches -- generalized polynomial chaos
(gPC). The gPC methods employ orthogonal polynomials in random space and take advantage of the
solution smoothness (whenever possible). The features of various gPC numerical schemes will be
reviewed. Furthermore, we will discuss some of the highly efficient algorithms that are based on gPC
and effective for simulations beyond uncertainty propagation. These algorithms are applicable for
problems such as inverse inference, data assimilation, reliability analysis, etc.

DOCTORAL DEFENSE

TIME: 11:00 a.m.

ROOM: Ayres Hall 406

SPEAKER: Mr. Nicholas Gewecke

TITLE: "Dynamics of Mushy Layers on a Finite Domain"

His committee consists of Professors: Schulze (chair), Alexiades, Lenhart, Gao (Materials Science).

**Wednesday, March 23**

APPLIED/COMPUTATIONAL MATH

TIME: 3:35 - 4:30 p.m.

ROOM: Ayres 111

SPEAKER: Professor Seddik Djouadi, EECS Department, UTK

TITLE: "On the Connection Between Model Reduction and Metric Complexity Theory"

ABSTRACT: The connection between two important model reduction techniques, namely
balanced proper orthogonal decomposition (POD) and balanced truncation is investigated
for infinite dimensional systems. In particular, balanced POD is shown to be optimal in
the sense of distance minimization in a space of integral operators. Balanced truncation

is shown to be a particular case of balanced POD for infinite dimensional systems for
which the impulse response satisfies certain finite energy constraints. Balanced
POD and balanced truncation are related to certain notions of metric complexity theory.
In particular both are shown to minimize different n-widths including the Kolmogorov,
Gelfand, and linear n-widths. The n-widths quantify inherent and representation errors
due to lack of data and loss of information.

ANALYSIS SEMINAR

TIME: 3:35 - 4:25 p.m.

ROOM: Ayres 114

SPEAKER: Professor Carl Sundberg

TOPIC: "The Dirac - Kadison/Singer - Paving - Feichtinger - Seip - Sundberg Conjectures"

ABSTRACT: I'm not kidding about this. The same type of question has arisen in many different areas,
such as Quantum Mechanics, C*-Algebra Theory, Frame Theory, and Function-Theoretic Operator
Theory (notice that I have shamelessly added my own name to this list). I will discuss these questions
and their interrelations.

**Thursday, March 24**

JUNIOR COLLOQUIUM

TIME: 3:35 - 4:25 p.m.

ROOM: Ayres 405

SPEAKER: Prof. Mike Langston

TITLE: TBA

ABSTRACT: TBA

Please come for pizza at 3:15.

**Past notices:**

winter break

Seminars from 2009-2010 academic year

Seminars from 2008-2009 academic year

Seminars from 2007-2008 academic year

Seminars from 2006-2007 academic year

Seminars from 2005-2006 academic year