1,977 research outputs found
Q-Learning applied to games: a reward focused study
Dissertação de mestrado integrado em Informatics EngineeringQ-Learning is one of the most popular reinforcement learning algorithms. It can solve different complex problems
with interesting tasks where decisions have to be made, all the while using the same algorithm with no interfer ence from the developer about specific strategies. This is achieved by processing a reward received after each
decision is made.
In order to evaluate the performance of Q-Learning on different problems, video games prove to be a great
asset for testing purposes, as each game has its own unique mechanics and some kind of objective that needs
to be learned. Furthermore, the results from testing different algorithms on the same conditions can be easily
compared.
This thesis presents a study on Q-Learning, from its origins and how it operates, showcasing various state of
the art techniques used to improve the algorithm and detailing the procedures that have become standard when
training Q-Learning agents to play video games for the Atari 2600.
Our implementation of the algorithm following the same techniques and procedures is ran on different video
games. The training performance is compared to the one obtained in articles that trained on the same games
and attained state of the art performance.
Additionally, we explored crafting new reward schemes modifying game default rewards. Various custom
rewards were created and combined to evaluate how they affect performance.
During these tests, we found that the use of rewards that inform about both good and bad behaviour led to
better performance, as opposed to rewards that only inform about good behaviour, which is done by default in
some games.
It was also found that the use of more game specific rewards could attain better results, but these also required
a more careful analysis of each game, not being easily transferable into other games.
As a more general approach, we tested reward changes that could incentivize exploration for games that were
harder to navigate, and thus harder to learn from. We found that not only did these changes improve exploration,
but they also improved the performance obtained after some parameter tuning.
These algorithms are designed to teach the agent to accumulate rewards. But how does this relate to game
score? To assess this question, we present some preliminary experiments showing the relationship between the
evolution of reward accumulation and game score.Q-Learning é um dos algoritmos mais populares de aprendizagem por reforço. Este consegue resolver vários
problemas complexos que tenham tarefas interessantes e decisões que devem ser tomadas. Para todos os
problemas, o mesmo algoritmo é utilizado sem haver interferência por parte do desenvolvedor sobre estratégias
específicas que existam. Isto tudo é alcançado processando uma recompensa que é recebida após tomar cada
decisão.
Para avaliar o desempenho de Q-Learning em problemas diferentes, os jogos eletrónicos trazem grandes
vantagens para fins de teste, pois cada jogo tem as suas próprias regras e algum tipo de objetivo que precisa de
ser compreendido. Além disso, os resultados dos testes usando diferentes algoritmos nas mesmas condições
podem ser facilmente comparados.
Esta tese apresenta um estudo sobre Q-Learning, explicando as suas origens e como funciona, apresentando
várias técnicas de estado da arte usadas para melhorar o algoritmo e detalhando os procedimentos padrão
usados para treinar agentes de Q-Learning a jogar jogos eletrónicos da Atari 2600.
A nossa implementação do algoritmo seguindo as mesmas técnicas e procedimentos é executada em diferentes jogos eletrónicos. O desempenho durante o treino é comparado ao desempenho obtido em artigos que
treinaram nos mesmos jogos e atingiram resultados de estado da arte.
Além disso, exploramos a criação de novos esquemas de recompensas, modificando as recompensas usadas
nos jogos por defeito. Várias recompensas novas foram criadas e combinadas para avaliar como afetam o
desempenho do agente.
Durante estes testes, observamos que o uso de recompensas que informam tanto sobre o bom como o mau
comportamento levaram a um melhor desempenho, ao contrário de recompensas que apenas informam sobre
o bom comportamento, que acontece em alguns jogos usando as recompensas por defeito.
Também se observou que o uso de recompensas mais específicas para um jogo pode levar a melhores
resultados, mas essas recompensas também exigem uma análise mais cuidadosa de cada jogo e não são
facilmente transferíveis para outros jogos.
Numa abordagem mais geral, testamos mudanças de recompensas que poderiam incentivar a exploração
em jogos mais difíceis de navegar e, portanto, mais difíceis de aprender. Observamos que estas mudanças não
só melhoraram a exploração, como também o desempenho obtido após alguns ajustes de parâmetros.
Estes algoritmos têm como objetivo ensinar o agente a acumular recompensas. Como é que isto está relacionado com a pontuação obtida no jogo? Para abordar esta questão, apresentamos alguns testes preliminares
que mostram a relação entre a evolução da acumulação de recompensas e da pontuação no jogo
Creating UNICORNS: Teaching IEP Literacy and Accommodation Self-Advocacy Through Asynchronous Interactive Video Modules
Data indicate that individuals who disclose their disability status to self-advocate for accommodations at the postsecondary level may be as rare as the mythical unicorn. During the 2019–20 school year in the United States, 7.3 million public education students aged 3–21 years received some form of special education services. These students account for 14% of the nation’s public school enrollment (Irwin et al., 2021). In one study, only 20% of high school students reported having received any instruction on reading and understanding their own Individualized Education Program (IEP; Agran & Hughes, 2008). In another study, only 19% of postsecondary students reported receiving services or accommodations, while 87% of the same sample reported receiving services or accommodations at the secondary level (Raue et al., 2011).
The current study explored the effects of a program designed to fill a research and instructional gap by teaching college-bound secondary students with hidden disabilities how to self-advocate for accommodations. The UNICORNS program delivered instruction via asynchronous interactive video modules (IVMs). The IVMs taught students about self-advocacy, and IEP literacy. The program used a mnemonic to teach eight target behaviors for self-advocating and requesting accommodations. The UNICORNS program included instruction on the four subskills within Test et al.’s (2005) conceptual model of self-advocacy. The study\u27s findings suggest that asynchronous IVMs positively impacted all participants. Implications for practice and future research are provided
A proof of the Ryser-Brualdi-Stein conjecture for large even
A Latin square of order is an by grid filled using symbols so
that each symbol appears exactly once in each row and column. A transversal in
a Latin square is a collection of cells which share no symbol, row or column.
The Ryser-Brualdi-Stein conjecture, with origins from 1967, states that every
Latin square of order contains a transversal with cells, and a
transversal with cells if is odd. Keevash, Pokrovskiy, Sudakov and
Yepremyan recently improved the long-standing best known bounds towards this
conjecture by showing that every Latin square of order has a transversal
with cells. Here, we show, for sufficiently large ,
that every Latin square of order has a transversal with cells.
We also apply our methods to show that, for sufficiently large , every
Steiner triple system of order has a matching containing at least
edges. This improves a recent result of Keevash, Pokrovskiy, Sudakov and
Yepremyan, who found such matchings with edges, and
proves a conjecture of Brouwer from 1981 for large .Comment: 71 pages, 13 figure
Tradition and Innovation in Construction Project Management
This book is a reprint of the Special Issue 'Tradition and Innovation in Construction Project Management' that was published in the journal Buildings
HM 32: New Interpretations in Naval History
Selected papers from the twenty-first McMullen Naval History Symposium held at the U.S. Naval Academy, 19–20 September 2019.https://digital-commons.usnwc.edu/usnwc-historical-monographs/1031/thumbnail.jp
Electron Thermal Runaway in Atmospheric Electrified Gases: a microscopic approach
Thesis elaborated from 2018 to 2023 at the Instituto de Astrofísica de Andalucía under the supervision of Alejandro Luque (Granada, Spain) and Nikolai Lehtinen (Bergen, Norway). This thesis presents a new database of atmospheric electron-molecule collision cross sections which was published separately under the DOI :
With this new database and a new super-electron management algorithm which significantly enhances high-energy electron statistics at previously unresolved ratios, the thesis explores general facets of the electron thermal runaway process relevant to atmospheric discharges under various conditions of the temperature and gas composition as can be encountered in the wake and formation of discharge channels
Behavior quantification as the missing link between fields: Tools for digital psychiatry and their role in the future of neurobiology
The great behavioral heterogeneity observed between individuals with the same
psychiatric disorder and even within one individual over time complicates both
clinical practice and biomedical research. However, modern technologies are an
exciting opportunity to improve behavioral characterization. Existing
psychiatry methods that are qualitative or unscalable, such as patient surveys
or clinical interviews, can now be collected at a greater capacity and analyzed
to produce new quantitative measures. Furthermore, recent capabilities for
continuous collection of passive sensor streams, such as phone GPS or
smartwatch accelerometer, open avenues of novel questioning that were
previously entirely unrealistic. Their temporally dense nature enables a
cohesive study of real-time neural and behavioral signals.
To develop comprehensive neurobiological models of psychiatric disease, it
will be critical to first develop strong methods for behavioral quantification.
There is huge potential in what can theoretically be captured by current
technologies, but this in itself presents a large computational challenge --
one that will necessitate new data processing tools, new machine learning
techniques, and ultimately a shift in how interdisciplinary work is conducted.
In my thesis, I detail research projects that take different perspectives on
digital psychiatry, subsequently tying ideas together with a concluding
discussion on the future of the field. I also provide software infrastructure
where relevant, with extensive documentation.
Major contributions include scientific arguments and proof of concept results
for daily free-form audio journals as an underappreciated psychiatry research
datatype, as well as novel stability theorems and pilot empirical success for a
proposed multi-area recurrent neural network architecture.Comment: PhD thesis cop
Paths and cycles in graphs and hypergraphs
In this thesis we present new results in graph and hypergraph theory all of which feature paths or cycles.
A -uniform tight cycle is a -uniform hypergraph on vertices with a cyclic ordering of its vertices such that the edges are all -sets of consecutive vertices in the ordering.
We consider a generalisation of Lehel's Conjecture, which states that every 2-edge-coloured complete graph can be partitioned into two cycles of distinct colour, to -uniform hypergraphs and prove results in the 4- and 5-uniform case.
For a -uniform hypergraph~, the Ramsey number is the smallest integer such that any 2-edge-colouring of the complete -uniform hypergraph on vertices contains a monochromatic copy of . We determine the Ramsey number for 4-uniform tight cycles asymptotically in the case where the length of the cycle is divisible by 4, by showing that = (5+(1)).
We prove a resilience result for tight Hamiltonicity in random hypergraphs. More precisely, we show that for any >0 and 3 asymptotically almost surely, every subgraph of the binomial random -uniform hypergraph in which all -sets are contained in at least edges has a tight Hamilton cycle.
A random graph model on a host graph is said to be 1-independent if for every pair of vertex-disjoint subsets of , the state of edges (absent or present) in is independent of the state of edges in . We show that = 4 - 2 is the critical probability such that every 1-independent graph model on where each edge is present with probability at least contains an infinite path
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