ECATI - Artigos de Revistas Internacionais com Arbitragem Científica

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http://hdl.handle.net/10437/10709

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Percorrer ECATI - Artigos de Revistas Internacionais com Arbitragem Científica por autor "HEI-LAB - Human Environment Interaction Lab"

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    Steady state particle swarm
    (PeerJ Inc., 2019) Fernandes, Carlos M.; Fachada, Nuno; Merelo, J. J.; Rosa, Agostinho C.; HEI-LAB - Human Environment Interaction Lab
    This paper investigates the performance and scalability of a new update strategy for the particle swarm optimization (PSO) algorithm. The strategy is inspired by the Bak–Sneppen model of co-evolution between interacting species, which is basically a network of fitness values (representing species) that change over time according to a simple rule: the least fit species and its neighbors are iteratively replaced with random values. Following these guidelines, a steady state and dynamic update strategy for PSO algorithms is proposed: only the least fit particle and its neighbors are updated and evaluated in each time-step; the remaining particles maintain the same position and fitness, unless they meet the update criterion. The steady state PSO was tested on a set of unimodal, multimodal, noisy and rotated benchmark functions, significantly improving the quality of results and convergence speed of the standard PSOs and more sophisticated PSOs with dynamic parameters and neighborhood. A sensitivity analysis of the parameters confirms the performance enhancement with different parameter settings and scalability tests show that the algorithm behavior is consistent throughout a substantial range of solution vector dimensions.
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    Videogame agency as a bio-costs contract
    (Universidade Católica Portuguesa, 2018) Neves, Pedro Pinto; Morgado, Leonel; Zagalo, Nelson; HEI-LAB - Human Environment Interaction Lab
    This paper presents a novel descriptive model for agency in videogames as communication. Literature pertaining to interactive works including videogames has identified the need to overcome dyadic perspectives of communication in such works. Research specifically to do with agency has called for agency to no longer be confused with freedom of action, for an integrated perspective of the player and the system, and for that relationship to be viewed as a conversation. The transactional model in this paper achieves this by proposing a nested hierarchy of levels of communication that operate as an implicit contract, negotiated between the system and the player, where the object of the transaction is bio-costs, effected through the signalling of the attainability of understandings. The paper describes research antecedents, a research agenda, the basis for the model, the model itself, examples of how the model can be used to describe videogame designs, and future research.