Tom Schaul, M.Sc.
Tom Schaul, M.Sc. is
a Ph.D. student in machine learning at
IDSIA, supervised by
Jürgen Schmidhuber. He works on reinforcement learning,
optimization, neural
networks, artificial curiosity, and related topics.
Tom is winner of the
2009 GECCO Best Paper Award and winner of the
Bronze medal at the 2000 International Mathematical Olympiad.
Tom’s research areas include:
Reinforcement learning
Within the broad framework of reinforcement learning he’s most
interested in
policy-gradient methods (that don’t use value functions, e.g.
reward-weighted regression). He’s currently working on new, general
benchmarks that should both make the plethora of RL algorithms more
comparable, and clearly show the limitations of each, thereby
simplifying the choice of algorithm for particular real-world
problems.
Black box optimization
In black box optimization he optimizes a fitness function in the absence
of any knowledge about it. It is only possible to evaluate the function
at a limited number of points in the (high-dimensional) parameter space.
The goal is to find parameters that correspond to high fitness with as
few evaluations as possible. He is working on improving the state of
the art for this problem with novel algorithms (e.g.
,
FEM).
Artificial curiosity
Humans explore the world quite efficiently, going for areas/topics that
they do not know well, but where they also expect to be able to learn
more about the world. In AI this idea has been formally introduced as
artificial curiosity. He’s currently trying to improve the
exploration
strategies of existing algorithms in reinforcement learning and
optimization based on this.
Multi-dimensional neural networks
Recurrent neural networks are among the most powerful tools for
sequence
learning. At IDSIA, he developed multi-dimensional RNNs that take this
idea one step further and can elegantly and compactly handle the spacial
structure of multi-dimensional sequences, like images, videos, or fMRI
scans. He showed that they
scale nicely on board games.
Games
Tom has always been interested in games, and they turn out to be
very
appropriate application domains for a variety of machine learning
techniques. He’s particularly interested in board games with spacial
structure and patterns (like
Go) or complex graph structure (like
Sokoban).
He coauthored
PyBrain,
Metalearning,
Towards Practical Universal Search,
Frontier Search,
Efficient Natural Evolution Strategies,
Stochastic Search using the Natural Gradient,
Scalable
Neural Networks for Board Games,
Ontogenetic and Phylogenetic Reinforcement Learning,
Fitness Expectation Maximization,
Countering Poisonous Inputs with Memetic Neuroevolution,
Natural Evolution Strategies, and
Episodic Reinforcement Learning by Logistic Reward-Weighted
Regression. Read the
full list of his publications!
Tom earned his Master’s in Computer Engineering with the thesis
Evolving a Compact Concept-based Sokoban Solver
at
École Polytechnique Fédérale de Lausanne
in 2005. He was an exchange student at
University of Waterloo from 2002 to 2003 and at
Columbia University from 2004 to 2005.
He attended
Machine Learning Summer School at
Cambridge University in 2009.
