## Scientific Lectures

- 23-Oct-07

Random projections of regular polytopes and neighborliness

If an N-dimensional regular crosspolytope is projected to a uniform random d-dimensional subspace and N is large, then the projection has strong neighborliness properties, with high probability. Strong results in this direction were recently obtai more››

University of Alberta

- 19-Oct-07

Finite element analysis of CAD large assemblies more››

Simon Fraser University

- 15-Oct-07

Nonsmooth, Nonconvex Optimization

There are many algorithms for minimization when the objective function is differentiable or convex, but few options when it is neither. We describe two simple algorithmic approaches for minimization of nonsmooth, nonconvex objectives: BFGS (a new more››

Simon Fraser University

- 13-Oct-07

21st Annual Pacific Northwest Numerical Analysis Seminar

http://www.amath.washington.edu/~pnwnas/2007/ more››

University of Washington

- 12-Oct-07

Unsolved for over twenty-five years, a surprisingly difficult conjecture stated that a non-crossing polygonal chain of fixed-length edges in the plane can be continuously opened without crossing. Gunter Rote, Erik Demaine and I proved this Carpent more››

University of Calgary

- 11-Oct-07

Why things don't fall down - Art, geometry and engineering

Why do some geometric shapes hold together, while others are floppy and fall down? An eggshell and a convex dome are rigid, while polygons, with four or more sides of fixed length in the plane, flex. The geometric principles for convex shapes go b more››

University of Calgary

- 11-Oct-07

MITACS Math Finance Seminar 2007

The Mutual Fund Theorem (MFT) is considered in a general semimartingale financial market $ with a finite time horizon T. It is established that: 1) If for given utility functions (i.e. investors) the MFT holds true in all Brown more››

University of British Columbia

- 10-Oct-07

The unfinished revolution: space, time and the quantum

Between 1905 and 1926 Einstein, Bohr and others initiated a scientific revolution by the introduction of quantum mechanics and relativity theory. The revolution is unfortunately still incomplete, because there are major unresolved issues. Th more››

University of British Columbia

- 10-Oct-07

The geometry of rigid and non-rigid structures

Convex triangulated surfaces in three-space are rigid by Cauchy's Theorem. But what about non-convex surfaces? Some interesting recent examples of classes of non-convex surfaces have some convex-like properties, and yet are still rigid. On the oth more››

University of Calgary

- 4-Oct-07

Total Positivity and its Applications

A matrix is called totally positive (resp. totally nonnegative)if all of its minors are positive (resp. nonnegative). This important class of matrices grew out of three separate applications: Vibrating systems, interpolation, and statistics. Since more››

University of Calgary

- 4-Oct-07
- 5-Oct-07

Optimal investment under partial information

We consider the problem of maximizing terminal utility in a model where asset prices are driven by Wiener processes, but where the various rates of returns are allowed to be arbitrary semi-martingales. The only information available to the investo more››

University of British Columbia

- 2-Oct-07

2-Dimensional Lp-Minkowski problem

et S^{n-1}subset R^n be the unit sphere. The L_p-Minkowski problem proposed by Lukwak is a natural generalization of the classical Minkowski problem. Analytically, it is equivalent to find positive solutions of the equation det( more››

University of British Columbia

- 2-Oct-07

Finite Element Analysis of CAD Large Assemblies

In today's product development and engineering process, usage of computer aided design (CAD) platform is obvious. It allows crating of quite realistic models, precisely describing not only the geometry of the developed prototype, but also its phys more››

University of British Columbia

- 29-Sep-07

6th Pacific Northwest PDE Meeting

The 6th Pacific Northwest PDE meeting will be held at Simon Fraser University in Burnaby on Saturday, September 29, 2007. more››

Simon Fraser University

- 28-Sep-07

Towards Robust Finite Element Formulations for Acoustics more››

Simon Fraser University

- 27-Sep-07

lambda(lambda(n)): A case study in analytic number theory

A 2005 result of Carl Pomerance and myself identifies the normal order (that is, the asymptotic size for 100% of integers) of the twice-iterated Carmichael lambda-function ?(?(n)), a function that arises when considering an exponential pseudorandom n more››

University of British Columbia

- 27-Sep-07

Powers in progression, Chebotarev, and Hilbert class polynomials

I will sketch some rather odd connections between ternary Diophantine equations, the Chebotarev Density Theorem and heights of Hilbert class polynom more››

University of British Columbia

- 27-Sep-07

Modeling the Spread of West Nile Virus

West Nile virus was detected in New York State in 1999, and has spread rapidly across the continent causing bird, horse and human mortality. The aim of this lecture is to model this spread. Biological assumptions are summarized and lead to the dev more››

University of British Columbia

- 26-Sep-07

- 26-Sep-07

Bounds on the Crosscap Numbers of Torus Knots

In joint work with Sizemore, we build on Teragaito's calculation of the crosscap number $c(K)$ of a torus knot $K$ to give bounds in terms of the genus $g(K)$ and crossing number $n(K)$: $c(K) leq lfloor (g(K) + 9)/6 floor$ and $c(K) leq l more››

University of British Columbia