560 research outputs found
Improved Reinforcement Learning with Curriculum
Humans tend to learn complex abstract concepts faster if examples are
presented in a structured manner. For instance, when learning how to play a
board game, usually one of the first concepts learned is how the game ends,
i.e. the actions that lead to a terminal state (win, lose or draw). The
advantage of learning end-games first is that once the actions which lead to a
terminal state are understood, it becomes possible to incrementally learn the
consequences of actions that are further away from a terminal state - we call
this an end-game-first curriculum. Currently the state-of-the-art machine
learning player for general board games, AlphaZero by Google DeepMind, does not
employ a structured training curriculum; instead learning from the entire game
at all times. By employing an end-game-first training curriculum to train an
AlphaZero inspired player, we empirically show that the rate of learning of an
artificial player can be improved during the early stages of training when
compared to a player not using a training curriculum.Comment: Draft prior to submission to IEEE Trans on Games. Changed paper
slightl
Temporal Difference Learning in Complex Domains
PhDThis thesis adapts and improves on the methods of TD(k) (Sutton 1988) that were
successfully used for backgammon (Tesauro 1994) and applies them to other complex
games that are less amenable to simple pattem-matching approaches. The games
investigated are chess and shogi, both of which (unlike backgammon) require
significant amounts of computational effort to be expended on search in order to
achieve expert play. The improved methods are also tested in a non-game domain.
In the chess domain, the adapted TD(k) method is shown to successfully learn the
relative values of the pieces, and matches using these learnt piece values indicate that
they perform at least as well as piece values widely quoted in elementary chess books.
The adapted TD(X) method is also shown to work well in shogi, considered by many
researchers to be the next challenge for computer game-playing, and for which there
is no standardised set of piece values.
An original method to automatically set and adjust the major control parameters used
by TD(k) is presented. The main performance advantage comes from the learning
rate adjustment, which is based on a new concept called temporal coherence.
Experiments in both chess and a random-walk domain show that the temporal
coherence algorithm produces both faster learning and more stable values than both
human-chosen parameters and an earlier method for learning rate adjustment.
The methods presented in this thesis allow programs to learn with as little input of
external knowledge as possible, exploring the domain on their own rather than by
being taught. Further experiments show that the method is capable of handling many
hundreds of weights, and that it is not necessary to perform deep searches during the
leaming phase in order to learn effective weight
The Hanabi Challenge: A New Frontier for AI Research
From the early days of computing, games have been important testbeds for
studying how well machines can do sophisticated decision making. In recent
years, machine learning has made dramatic advances with artificial agents
reaching superhuman performance in challenge domains like Go, Atari, and some
variants of poker. As with their predecessors of chess, checkers, and
backgammon, these game domains have driven research by providing sophisticated
yet well-defined challenges for artificial intelligence practitioners. We
continue this tradition by proposing the game of Hanabi as a new challenge
domain with novel problems that arise from its combination of purely
cooperative gameplay with two to five players and imperfect information. In
particular, we argue that Hanabi elevates reasoning about the beliefs and
intentions of other agents to the foreground. We believe developing novel
techniques for such theory of mind reasoning will not only be crucial for
success in Hanabi, but also in broader collaborative efforts, especially those
with human partners. To facilitate future research, we introduce the
open-source Hanabi Learning Environment, propose an experimental framework for
the research community to evaluate algorithmic advances, and assess the
performance of current state-of-the-art techniques.Comment: 32 pages, 5 figures, In Press (Artificial Intelligence
Temoral Difference Learning in Complex Domains
Submitted to the University of London for the Degree of Doctor of Philosophy in Computer Scienc
Overview of deep reinforcement learning in partially observable multi-agent environment of competitive online video games
In the late 2010’s classical games of Go, Chess and Shogi have been considered ’solved’ by deep
reinforcement learning AI agents. Competitive online video games may offer a new, more challenging environment for deep reinforcement learning and serve as a stepping stone in a path to real
world applications. This thesis aims to give a short introduction to the concepts of reinforcement
learning, deep networks and deep reinforcement learning. Then the thesis proceeds to look into few
popular competitive online video games and to the general problems of AI development in these
types of games. Deep reinforcement learning algorithms, techniques and architectures used in the
development of highly competitive AI agents in Starcraft 2, Dota 2 and Quake 3 are overviewed.
Finally, the results are looked into and discussed
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