Speaker: Vakhtang Putkaradze
Centennial Professor
Department of Mathematics and Statistics
Department of Chemical Engineering
PIMS Site Director at the University of Alberta
Title: Dynamics and control of flexible solar towers
Abstract:
The use of solar chimneys for energy production has been suggested more than 100 years ago. Unfortunately, this technology has not been realized on a commercial scale, in large part due to the high cost of erecting tall towers using traditional methods of construction. Recent works have suggested a radical decrease in tower cost by using an inflatable self-supported tower consisting of stacked toroidal bladders. While the statics deflections of such towers under constant wind have been investigated before, the key for further development of this technology lies in the analysis of dynamics, which is the main point of this talk. Using Lagrangian reduction by symmetry, we develop a fully three dimensional theory of motion for such towers and study the tower’s stability and dynamics. Next, we derive a geometric theory of optimal control for the tower dynamics using variable pressure inside the bladders, and perform detailed analytical and numerical studies of the control in two dimensions. Finally, we report on the results of experiments demonstrating the remarkable stability of the tower in real-life conditions, showing good agreement with theoretical results. This work has been supported by NSERC and the University of Alberta.
Title: Non-homogeneous harmonic analysis, Geometric Measure Theory and fine structures of harmonic measure
Abstract: One of the goals of harmonies analysis is to study singular integrals. Singular integrals are ubiquitous objects in PDE and in Mathematical Physics, and as it turned out recently, play an important part in Geometric Measure Theory. They have various degrees of singularity, and the simplest ones are called Calder’on–Zygmund operators. Their theory was completed in the 50′s by Zygmund and Calder’on. Or it seemed like that. The last 20 years saw the need to consider CZ operators in
very bad environment, so kernels are still very good, but the ambient set has no regularity whatsoever.
Initially such situations appeared from the wish to solve some outstanding problems in complex analysis: such as Painlev’e’s, Ahlfors’, Denjoy’s and Vitushkin’s problems.
But recently it turned out that the non-homogeneous harmonic analysis (=the analysis of CZ operators on very bad sets and measures) is also very fruitful in the part of Geometric Measure Theory that deals with rectifiability, and also helps a lot to understand the geometry of harmonic measure. The research on the geometric properties of harmonic measures was pioneered in the U. of M. in the 60-70′s by George Piranian, and came to fruition in the later works (80-90′s) by Lennart Carleson, Nikolai Makarov, Jean Bourgain, Peter Jones and Tom Wolff. But most of the results concerned the structure of harmonic measure of planar domains. As an example of the use of non-homogeneous harmonic analysis, we will show how it allows us to understand very fine property of harmonic measure of any domain in any dimension.
Title: The Joy of Functional Programming in Haskell
Speaker: Jake Fennick
Time: 3pm Tuesday April 18, 2017
Location: Keller 401
Abstract:
The goal of this talk is to convey to you the experience of pure joy
and excitement when using Haskell, and to help you actually get
started programming in Haskell. After a basic introduction to the
language, we will cover
1. The development environment and getting set up
2. More advanced language features
3. Some mathematical patterns and functional programming idioms
4. Lots of fancy demos such as plotting/visualization, LaTeX, algorithmic music generation, high performance computing, etc.
5. A little bit of theory
This will be a coding talk, so we will primarily be walking through
code and actually getting set up. The code (including installation
scripts) is at https://github.com/TypeFunc/uh-mfc I hope to cover a
lot of material, so I encourage you to check it out but it isn’t
strictly necessary.
Speaker: Ruth Haas (UHM)
How to get an academic job in the mathematical sciences
Getting a tenure track job is great! How can you increase your chances of getting a job you like?
The time to act is now- when you are not actively looking, and when you have time to gain a variety of professional experiences that will help you attract the attention of employers.
Mathematicians get jobs at all sorts of different kinds of colleges and universities. In this talk I’ll describe some of the different kinds of institutions, both what it would be like to work there, and what they look for in job applicants. I’ll also discuss the parts of a job application and how you can (and should) tailor your application for different jobs. Industy and government jobs will be discussed briefly as well.
This talk is especially for graduate students and postdocs.
Title: Short-term Forecasting of Weather and Cancer: Finding
Initial Conditions and Parameters for Dynamical Models from Noisy Data
Speaker: Eric Kostelich, School of Mathematical & Statistical Sciences,
Arizona State University
Abstract: Computer models are essential to modern weather prediction.
They implement numerical methods to approximate the solutions of the
so-called primitive equations of atmospheric flow, but like any
differential equations, initial conditions must be supplied. However,
it is not possible to measure the state of the atmosphere at every model
grid point. Data assimilation refers to a class of methods to infer the
initial conditions from a sparse set of initial conditions and a set
of numerical forecasts. I will provide an overview of the problem
and describe a particular data assimilation method that is highly
accurate and efficient for numerical weather prediction and related
models. In addition, I will survey some potential applications
(and inherent difficulties) of data assimilation in mathematical
biology, especially differential equation models of prostate cancer
and glioma (brain tumors).
Bio: Eric Kostelich is President’s Professor of Mathematics at
Arizona State University. He received his Ph.D. degree in applied
mathematics from the University of Maryland at College Park and completed
postdoctoral work in physics at the University of Texas, Austin.
His research interests are in nonlinear dynamical systems, mathematical
biology, and high-performance computing, including data assimilation
for geophysical flows. Professor Kostelich was one of the principal
investigators in the Mathematics and Climate Research Network,
supported by the National Science Foundation. He has directed
undergraduate research program in computational mathematics at ASU
since 2008. He is a member of the Society for Industrial and Applied
Mathematics, the American Mathematical Society, and the American
Meteorological Society.