ESTG - Artigos em revistas internacionais
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Browsing ESTG - Artigos em revistas internacionais by Field of Science and Technology (FOS) "Ciências Naturais::Ciências Físicas"
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- High-pressure range shock wave data for syntactic foamsPublication . Ribeiro, J.; Mendes, R.; Plaksin, I.; Campos, J.; Capela, Carlos; Elert, Mark; Furnish, Michael D.; Anderson, William W.; Proud, William G.; Butler, William T.Syntactic foams [SF] are a porous composite material resulting from the mixture of Hollow Glass Micro Spheres [HGMS] with a polymeric binder. Beyond a set of technological advantages over the polymer considered alone, SF present as an essential feature the possibility to control in wide limits the amount, the shape and the size of the pores and for that reason are being used for benchmarking in the area of shock wave [SW] behavior of porous materials. In this paper, SW loading experiments of SF samples were performed in order to assess the high-pressure range Hugoniot equation of state as a function of the SF initial density. Hugoniot data were assessed coupling the SW velocity within the SF samples with the SW velocity in a reference material or with manganin gauge results. The results obtained present a significant variation with the initial specific mass and can be described with appreciable precision by the Thouvenin/Hofmann Plate Gap model, while the concordance between the experimental results and the Gruüneisen model seems to be very dependent on the Gruüneisen coefficient values.
- The Value of Information Searching against Fake NewsPublication . Martins, José; Pinto, AlbertoInspired by the Daley-Kendall and Goffman-Newill models, we propose an Ignorant-Believer-Unbeliever rumor (or fake news) spreading model with the following characteristics: (i) a network contact between individuals that determines the spread of rumors; (ii) the value (cost versus benefit) for individuals who search for truthful information (learning); (iii) an impact measure that assesses the risk of believing the rumor; (iv) an individual search strategy based on the probability that an individual searches for truthful information; (v) the population search strategy based on the proportion of individuals of the population who decide to search for truthful information; (vi) a payoff for the individuals that depends on the parameters of the model and the strategies of the individuals. Furthermore, we introduce evolutionary information search dynamics and study the dynamics of population search strategies. For each value of searching for information, we compute evolutionarily stable information (ESI) search strategies (occurring in non-cooperative environments), which are the attractors of the information search dynamics, and the optimal information (OI) search strategy (occurring in (eventually forced) cooperative environments) that maximizes the expected information payoff for the population. For rumors that are advantageous or harmful to the population (positive or negative impact), we show the existence of distinct scenarios that depend on the value of searching for truthful information. We fully discuss which evolutionarily stable information (ESI) search strategies and which optimal information (OI) search strategies eradicate (or not) the rumor and the corresponding expected payoffs. As a corollary of our results, a recommendation for legislators and policymakers who aim to eradicate harmful rumors is to make the search for truthful information free or rewarding.