Department of Computer Science | Institute of Theoretical Computer Science | CADMO

Theory of Combinatorial Algorithms

Prof. Emo Welzl and Prof. Bernd Gärtner

Mittagsseminar (in cooperation with A. Steger, D. Steurer and B. Sudakov)

Mittagsseminar Talk Information

Date and Time: Tuesday, March 22, 2011, 12:15 pm

Duration: This information is not available in the database

Location: OAT S15/S16/S17

Speaker: Kenneth Clarkson (IBM Research Almaden)

Sublinear Optimization for Machine Learning

I will describe randomized approximation algorithms for some classical problems of machine learning, where the algorithms have provable bounds that hold with high probability. Some of our algorithms are sublinear, that is, they do not need to touch all the data. Specifically, for a set of points a_1...a_n in d dimensions, we show that finding a d-vector x that approximately maximizes the margin min_i a_i dot x can be done in O(n+d)/epsilon^2 time, up to logarithmic factors, where epsilon>0 is an additive approximation parameter. Our algorithm is a primal-dual version of the classical perceptron training algorithm, in which both the primal and the dual variables are updated using randomization. We have a similar result for the problem of finding the smallest ball containing the input points. We also give versions of our algorithms for the Gaussian and polynomial kernels, with an additional runtime cost of O(1/epsilon^5).

Joint work with Elad Hazan and David Woodruff.

Upcoming talks     |     All previous talks     |     Talks by speaker     |     Upcoming talks in iCal format (beta version!)

Previous talks by year:   2024  2023  2022  2021  2020  2019  2018  2017  2016  2015  2014  2013  2012  2011  2010  2009  2008  2007  2006  2005  2004  2003  2002  2001  2000  1999  1998  1997  1996  

Information for students and suggested topics for student talks

Automatic MiSe System Software Version 1.4803M   |   admin login