Building a poker playing agent based on game logs using supervised learning

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 201

Applying machine learning techniques to an imperfect information game

The game of poker presents a challenging game to Artificial Intelligence researchers because it is a complex asymmetric information game. In such games, a player can improve his performance by inferring the private information held by the other players from their prior actions. A novel connectionist structure was designed to play a version of poker (multi-player limit Hold‟em). This allows simple reinforcement learning techniques to be used which previously not been considered for the game of multi-player hold‟em. A related hidden Markov model was designed to be fitted to records of poker play without using any private information. Belief vectors generated by this model provide a more convenient and flexible representation of an opponent‟s action history than alternative approaches. The structure was tested in two settings. Firstly self-play simulation was used to generate an approximation to a Nash equilibrium strategy. A related, but slower, rollout strategy that uses Monte-Carlo samples was used to evaluate the performance. Secondly the structure was used to model and hence exploit a population of opponents within a relatively small number of games. When and how to adapt quickly to new opponents are open questions in poker AI research. A opponent model with a small number of discrete types is used to identify the largest differences in strategy between members of the population. A commercial software package (Poker Academy) was used to provide a population of sophisticated opponents to test against. A series of experiments was conducted to compare adaptive and static systems. All systems showed positive results but surprisingly the adaptive systems did not show a significant improvement over similar static systems. The possible reasons for this result are discussed. This work formed the basis of a series of entries to the computer poker competition hosted at the annual conferences of the Association for the Advancement of Artificial Intelligence (AAAI). Its best rankings were 3rd in the 2006 6-player limit hold‟em competition and 2nd in the 2008 3-player limit hold‟em competition

A critical exploration of Facebook: The corporation and its users.

This study looks at Facebook by applying critical media/cultural studies (Kellner, 1995). Facebook is analysed, on the one hand, as a corporation pursuing profit, and, on the other hand, as a tool used by millions of people for all kinds of reasons. As a result, a dialectic emerges between looking at Facebook as a part of capitalism, and looking at Facebook as a part of popular culture. By analysing Facebook as a corporation, underpinned by theoretical knowledge derived from critical studies of communication and media (Fuchs 2008, 2009, 2010, 2011, 2012, 2013) this study will look at Facebook from a macro point of view. Is Facebook capable of reinforcing democracy? What role does it play in terms of surveillance? What kind of power can we find on Facebook? To what extent does Facebook mirror and reinforce some aspects of social life, situated within capitalistic system? Theory is combined with empirical data derived from ethnographic observation and interviews with users of Facebook. While Facebook is first of all a corporation, whose main drive is profit, people log on to it on a daily basis to have fun, to connect with friends, to join causes or in order to participate in a debate. What role does Facebook play in the daily lives of its users, why do people use it and what can Facebook tell us about friendship, community and identity? And finally, how can we call a Facebook user which works for Facebook as a corporation, by providing data for it, and deriving benefits from using it at the same time? By combining both macro and micro points of view, the aim of this study is to reach a better understanding of such a phenomenon as Facebook, and thus, of a society in which it is used. The purpose is to look at Facebook as both cultural artefact and cultural context (Hine 2000) and to see what role it plays in the contemporary society and in the daily lives of its users.On a more specific, UK-based level, the aim is to examine one new cultural form, Facebook, as a case study which will provide insights into perceptions of some of the dynamics of wider social cultural understandings and the changing patterns of everyday life as a result of the increasing role of the Internet in contemporary society