Lattices and discrete methods in cooperative games and decisions

Questa tesi si pone l'obiettivo di presentare la teoria dei giochi, in particolare di quelli cooperativi, insieme alla teoria delle decisioni, inquadrandole formalmente in termini di matematica discreta. Si tratta di due campi dove l'indagine si origina idealmente da questioni applicative, e dove tuttavia sono sorti e sorgono problemi più tipicamente teorici che hanno interessato e interessano gli ambienti matematico e informatico. Anche se i contributi iniziali sono stati spesso formulati in ambito continuo e utilizzando strumenti tipici di teoria della misura, tuttavia oggi la scelta di modelli e metodi discreti appare la più idonea. L'idea generale è quindi quella di guardare fin da subito al complesso dei modelli e dei risultati che si intendono presentare attraverso la lente della teoria dei reticoli. Ciò consente di avere una visione globale più nitida e di riuscire agilmente ad intrecciare il discorso considerando congiuntamente la teoria dei giochi e quella delle decisioni. Quindi, dopo avere introdotto gli strumenti necessari, si considerano modelli e problemi con il fine preciso di analizzare dapprima risultati storici e solidi, proseguendo poi verso situazioni più recenti, più complesse e nelle quali i risultati raggiunti possono suscitare perplessità. Da ultimo, vengono presentate alcune questioni aperte ed associati spunti per la ricerca.

The creation and use of an international reference glossary specific for horror role-playing games

This thesis focuses on the technical approach to the translation of the Italian horror role-playing game Sine Requie into English. It aims to prove that both the role-playing and horror aspects of the genre are important to convey an enjoyable experience to the players, and that it is possible to create and international reference glossary to better translate the horror genre itself. Following a brief introduction of the history of role-playing games (RPGs), we will look at the RPG technical vocabulary in Sine Requie, and analyze which of these elements can be translated following the great models of the history of role-playing games. A brief introduction will follow regsrding the horror genre and its core characteristics based on the work of worldwide famous horror writer H.P. Lovecraft. Lastly, a description on how the international reference glossary for the horror genre was created will be presented along with a few examples of its practical use.

Natural History on Blocks, in Bodies, and on the Hearth: Juvenile Science Literature and Games, 1850-1875.

This article examines the role of domestic spaces and images in mid-nineteenth-century science writing for children. Analyses of John Mill’s The Fossil Spirit, A.L.O.E.’s Fairy Frisket, John Cargill Brough’s The Fairy Tales of Science, Annie Carey’s “Autobiography of a Lump of Coal,” and an assortment of boxed games reveal a variety of ways in which overwhelming scientific concepts are domesticated. Moreover, juvenile science literature contributes this appeasing domestication to the broader scientific discourse, consistently framing natural history in terms of human experience.

Spike-based decision learning of nash equilibria in two-player games

Humans and animals face decision tasks in an uncertain multi-agent environment where an agent's strategy may change in time due to the co-adaptation of others strategies. The neuronal substrate and the computational algorithms underlying such adaptive decision making, however, is largely unknown. We propose a population coding model of spiking neurons with a policy gradient procedure that successfully acquires optimal strategies for classical game-theoretical tasks. The suggested population reinforcement learning reproduces data from human behavioral experiments for the blackjack and the inspector game. It performs optimally according to a pure (deterministic) and mixed (stochastic) Nash equilibrium, respectively. In contrast, temporal-difference(TD)-learning, covariance-learning, and basic reinforcement learning fail to perform optimally for the stochastic strategy. Spike-based population reinforcement learning, shown to follow the stochastic reward gradient, is therefore a viable candidate to explain automated decision learning of a Nash equilibrium in two-player games.

Capuchin Monkeys (Cebus apella) Fail to Be Equitable in an Ultimatum Game

The ultimatum game is a commonly used economics game testing humans' sense of fairness. In the game, a "proposer" is given a sum of money and is told they can split it however they want with another human partner. The partner can then either accept the division and both proposer and responder receive the proposed amounts, or the responder can reject the offer and neither player will get anything. Human subjects from most western cultures typically share almost half of an allotted amount, but it remains unknown whether our close primate relatives share this generosity. Recent attempts to present chimpanzees with the ultimatum game have provided inconclusive results, with some studies finding the animals share humans' disposition to behave 'fairly' and others concluding that chimpanzees act selfishly to maximize their own rewards. Capuchin monkeys are known to share many human and chimpanzee social and cooperative behaviors, and this study was the first to present capuchin monkeys with a version of the ultimatum game. Subjects were presented with two differently colored tokens representing different qualitative reward contingencies, one equitable and the other inequitable in favor of the subject proposer. Subjects could select and place one of the tokens in a transfer container. The capuchins were first tested with a "dictator game" where, after the subject monkey selected a token, the rewards (equitable or inequitable) were distributed to the subject and a nearby partner monkey that was not an active participant. The capuchins were then tested on an ultimatum game in which after the subject selected and placed a token in the container, the container was moved to the partner. The partner needed to remove the token and transfer it back to the experimenter for the rewards to be distributed. As such, the partner could reject the subject's offer by refusing to participate and neither would receive a reward. The experiment was conducted to determine if the subject monkey would select the equitable reward option rather than the selfish option in order to maintain the partner's cooperation in the task. Capuchin subjects behaved selfishly and selected the inequitable token significantly more often than the equitable token in both the dictator and ultimatum game with no significant difference in preference between the two games. Interestingly, despite the occasional occurrence of rejection by the partner monkeys (resulting in no reward for the subject), subjects never altered their strategy, continuing to prefer the selfish token. The study may indicate that capuchin monkeys have an inability to judge the effect of their behavior on a conspecific's reward outcome, or an indifference to the outcome if there is an individual cost associated with behaving prosocially.