Print Friendly printer friendly
George Wechslberger
Technical University of Munich
Thu 21 Sep 2017, 3:00pm SPECIAL
LSK 306
Overview of the Julia programming language: an 8 hour minicourse Part III
LSK 306
Thu 21 Sep 2017, 3:00pm-5:30pm


Course description: The Julia programming language is designed to be a high level language for numerical computing, that is as fast as C or Fortran, despite employing a high level syntax. Since its first release in 2012 it has been continually improved and build a fast growing community around it.

The aim of this course is to give an overview of the key concepts of the Julia programming language as well as explain the advantages over other languages designed for numerical computing, as e.g. Matlab or R. Furthermore it demonstrates how readily available packages developed with Julia can be used to solve common problems occurring in numerical analysis, such as - linear systems of equations - non linear systems of equations - ordinary differential equations - linear programs. The course will also cover the basic tasks frequently encountered by numerical analysts: benchmarking, plotting and debugging. If time permits we will also explore possibilities for using Julia in deep learning applications.
UBC Math
Fri 22 Sep 2017, 3:00pm
Department Colloquium
ESB 2012
Some directions in analysis and geometry of probability measures
ESB 2012
Fri 22 Sep 2017, 3:00pm-4:00pm


Probability measures are key objects in many scientific and engineering areas that deal with randomness, distributions, data sets, etc. When coupled with optimization, many interesting questions naturally arise. In this talk, I will explain a few of such questions from the point of view of optimal transport theory, which gives a natural and robust framework for studying probability measures. These involve among others, matching probability measures in an optimal way following certain rules (e.g martingale), as well as finding geometric averages between probability measures.  

Note for Attendees

Light refreshments will be served in ESB 4133, the PIMS Lounge before this colloquium.
Tue 26 Sep 2017, 4:00pm
Discrete Math Seminar
ESB 4127
Combinatorial bases of polynomials
ESB 4127
Tue 26 Sep 2017, 4:00pm-5:00pm


We establish a poset structure on combinatorial bases of polynomials, defined by positive expansions. These bases include the well-studied Schubert polynomials, Demazure characters and Demazure atoms, as well as the recently-introduced slide and quasi-key bases. The product of a Schur polynomial and an element of a basis in the poset expands positively in that basis; in particular we give the first Littlewood-Richardson rule for the product of a Schur polynomial and a quasi-key polynomial, extending the rule of Haglund, Luoto, Mason and van Willigenburg for quasi-Schur polynomials. We also establish bijections connecting combinatorial models for these polynomials, including semi-skyline fillings and quasi-key tableaux.
The University of Melbourne
Wed 27 Sep 2017, 3:00pm
Discrete Math Seminar / Probability Seminar
ESB 2012
1324 pattern-avoiding permutations
ESB 2012
Wed 27 Sep 2017, 3:00pm-4:00pm


The field of pattern-avoiding permutations was introduced by Knuth in the 1960s as a way of characterising certain data structures. 
Since then, it has grown into an important area in its own right. There are a number of classical problems, among which is the number of 1324-avoiding 
permutations. We will give some history, and then give  details of a new algorithm we have developed for the generating function for this problem. 
As a result we can count these up to length 50.

A new method of analysis we have developed, which can in some circumstances be an alternative to Monte Carlo analysis, reveals some interesting features. 
In particular, we conjecture that the generating function is not D-finite, and has asymptotics that include a stretched-exponential term. 
(Joint work with Andrew Conway and Paul Zinn-Justin).

The late, great Mark Kac often said that his seminars assumed zero knowledge but infinite wisdom. 
This seminar only assumes zero knowledge and finite wisdom.