Scientific

Sparse Linear Models

Speaker: 
Trevor Hastie
Date: 
Tue, Sep 17, 2013
Location: 
PIMS, University of British Columbia
Conference: 
Statistics
Abstract: 

In a statistical world faced with an explosion of data, regularization has become an important ingredient. In many problems, we have many more variables than observations, and the lasso penalty and its hybrids have become increasingly useful. This talk presents a general framework for fitting large scale regularization paths for a variety of problems. We describe the approach, and demonstrate it via examples using our R package GLMNET. We then outline a series of related problems using extensions of these ideas. This is joint work with Jerome Friedman, Rob Tibshirani and Noah Simon.

 

Trevor Hastie is noted for his many contributions to the statistician’s toolbox of flexible data analysis methods.  Beginning with his PhD thesis, Trevor developed a nonparametric version of principal components analysis, terming the methodology principal curves and surfaces.  During the years after his PhD, as a member of the AT&T Bell Laboratories statistics and data analysis research group, Trevor developed techniques for linear, generalized linear, and additive models and worked on the development of S, the pre-cursor of R.  Much of this work is contained in the well-known Statistical Computing in S (co-edited with John Chambers, 1991).   In the book Generalized Additive Models (1990) Trevor and co-author Rob Tibshirani modified techniques like multiple linear regression and logistic regression to allow for smooth modeling while avoiding the usual dimensionality problems.  In 1994, Trevor left Bell Labs for Stanford University, to become Professor in Statistics and Biostatistics.  Trevor has applied his skills to research in machine learning.  His book Elements of Statistical Learning (with Rob Tibshirani and Jerry Friedman, Springer 2001; second edition 2009) is famous for providing a readable account of flexible techniques for high dimensional data.  This popular book expertly bridges the philosophical and research gap between computer scientists and statisticians.
 

Class: 

Explicit isogenies and endomorphisms of low-genus Jacobians: theory and applications

Author: 
Benjamin Smith
Date: 
Wed, Jun 19, 2013 to Fri, Jun 21, 2013
Location: 
PIMS, University of Calgary
Conference: 
Workshop on Curves and Applications
Abstract: 

Explicit isogenies and endomorphisms of low-genus Jacobians: theory and applications

Notes: 
Class: 
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The state-of-the-art in hyperelliptic curve cryptography

Author: 
Craig Costello
Date: 
Wed, Jun 19, 2013 to Fri, Jun 21, 2013
Location: 
PIMS, University of Calgary
Conference: 
Workshop on Curves and Applications
Abstract: 

The state-of-the-art in hyperelliptic curve cryptography

Notes: 
Class: 
Subject: 

Splitting of Abelian varieties

Author: 
V. Kumar Murty
Date: 
Wed, Jun 19, 2013 to Fri, Jun 21, 2013
Location: 
PIMS, University of Calgary
Conference: 
Workshop on Curves and Applications
Abstract: 

Splitting of Abelian varieties

Notes: 
Class: 
Subject: 

Search games and Optimal Kakeya Sets

Speaker: 
Yuval Peres
Date: 
Fri, Sep 6, 2013
Location: 
PIMS, University of British Columbia
Conference: 
PIMS/UBC Distinguished Colloquium Series
Abstract: 

A planar set that contains a unit segment in every direction is called a Kakeya set. These sets have been studied intensively in geometric measure theory and harmonic analysis since the work of Besicovich (1928); we find a new connection to game theory and probability. A hunter and a rabbit move on an n-vertex cycle without seeing each other until they meet. At each step, the hunter moves to a neighboring vertex or stays in place, while the rabbit is free to jump to any node. Thus they are engaged in a zero sum game, where the payoff is the capture time. We show that every rabbit strategy yields a Kakeya set; the optimal rabbit strategy is based on a discretized Cauchy random walk, and it yields a Kakeya set K consisting of 4n triangles, that has minimal area among such Kakeya sets. Passing to the scaling limit yields a simple construction of a random Kakeya set with zero area from two Brownian motions. (Talk based on joint work withY. Babichenko, R. Peretz, P. Sousi and P. Winkler). 

Class: 
Subject: 

Mathematics and the Planet Earth: a Long Life Together II

Speaker: 
Ivar Ekeland
Date: 
Wed, Jul 17, 2013
Location: 
PIMS, University of British Columbia
Conference: 
Mathematics of Planet Earth 2013
Abstract: 

When Colombus left Spain in 1492, sailing West, he knew that the Earth was round and was expecting to land in Japan. Seventeen centuries earlier, around 200 BC, Eratosthenes had shown that its circumference was 40,000 km, just by a smart use of mathematics, without leaving his home town of Alexandria. Since then, we have learned much more about Earth: it is a planet, it has an inner structure, it carries life , and at every step mathematics have been a crucial tool of discovery and understanding. Nowadays, concerns about the human footprint and climate change force us to bring all this knowledge to bear on the global problems facing us. This is the last challenge for mathematics: can we control change?
This is a two-part lecture, investigating how our idea of the world has influenced the development of mathematics. In the first lecture on July 15, I will describe the situation up to the twentieth century, in the second one on July 17 I will follow up to the present time and the global challenges humanity and the planet are facing today.
 

Class: 

Mathematics and the Planet Earth: a Long Life Together I

Speaker: 
Ivar Ekeland
Date: 
Mon, Jul 15, 2013
Location: 
PIMS, University of British Columbia
Conference: 
Mathematics of Planet Earth 2013
Abstract: 

When Colombus left Spain in 1492, sailing West, he knew that the Earth was round and was expecting to land in Japan. Seventeen centuries earlier, around 200 BC, Eratosthenes had shown that its circumference was 40,000 km, just by a smart use of mathematics, without leaving his home town of Alexandria. Since then, we have learned much more about Earth: it is a planet, it has an inner structure, it carries life , and at every step mathematics have been a crucial tool of discovery and understanding. Nowadays, concerns about the human footprint and climate change force us to bring all this knowledge to bear on the global problems facing us. This is the last challenge for mathematics: can we control change?

This is a two-part lecture, investigating how our idea of the world has influenced the development of mathematics. In the first lecture (July 15), I will describe the situation up to the twentieth century, in the second one (July 17) I will follow up to the present time and the global challenges humanity and the planet are facing today.

Class: 

Taking Advantage of Degeneracy in Cone Optimization: with Applications to Sensor Network Localization

Author: 
Henry Wolkowicz
Date: 
Thu, Aug 8, 2013 to Sat, Aug 10, 2013
Location: 
PIMS, University of British Columbia
Conference: 
Workshop on Numerical Linear Algebra and Optimization
Abstract: 

Taking Advantage of Degeneracy in Cone Optimization: with Applications to Sensor Network Localization

Class: 

Search Games and Optimal Kakeya Sets

Author: 
Yuval Peres
Date: 
Fri, Sep 6, 2013
Location: 
PIMS, University of British Columbia
Abstract: 

Search Games and Optimal Kakeya Sets: Yuval Peres
Based on joint work with Y. Babichenko, R. Peretz, P. Sousi and P. Winkler

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Subject: 

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