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: Thursday, December 19, 2013, 12:15 pm

Duration: 30 minutes

Location: OAT S15/S16/S17

Speaker: Hemant Tyagi

The adversarial multi-armed bandit problem

In this talk, we will look at some results from a paper by Auer et al. (SIAM J. Comput.'02) on the adversarial version of the classical multi-armed bandit problem. In this problem version, a player is given access to a set of K strategies (or arms). At each round t=1,2,.. the player chooses a strategy and receives a corresponding reward for it. The rewards are assumed to be assigned to the strategies by an adversary arbitrarily. The goal of the player is to play the strategies so as to minimize the cumulative expected regret i.e. the difference between the total expected reward of the best constant sequence of strategies and the total expected reward obtained by the player over T rounds. Assuming the adversary to be oblivious to the actions of the player we will first see a randomized algorithm that achieves a regret bound of O((K T log K)1/2) against all oblivious adversaries. We will then look at the construction of a hard adversary against which any algorithm incurs a regret of \Omega((KT)1/2).

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