6,608 research outputs found

    Tyre-road noyse: annoyance and detection of incoming traffic

    Get PDF
    In this paper, annoyance ratings and detection thresholds of incoming traffic are discussed as a function of road-tyre noise. Empirical data on annoyance, from the Noiseless project, can be interpreted as follows: (1) cobble stones pavements were significantly the most annoying; (2) the open asphalt rubber pavement had lower annoyance ratings but it did not differ significantly from the dense asphalt; (3) increasing speeds and traffic densities always led to higher annoyance ratings. On the other hand, as far as safety and detection of incoming traffic is concerned: (1) the hybrid vehicle was the least detected whereas the pickup truck was the most detected; (2) a clear effect of pavement type was found, with less detections for the asphalt rubber pavement while the cobble stones pavement always provided good detection.FCOMP-01-0124-FEDER-007560; COMP-01-0124- FEDER-022674FCOMP-01-0124-FEDER-022674PEst-OE/ECI/UI4047/2011info:eu-repo/semantics/publishedVersio

    Analysis of sodium intake from bread in an institutionalized elderly population

    Get PDF
    Poster presented at the Nutrition 2014: III World Congress of Public Health Nutrition = III Congresso Mundial de Nutrição e Saúde Pública. Las Palmas de Gran Canaria, Spain, 9-12 November 201

    Perception of speed in biological motion : more resistant to interference?

    Get PDF
    O sistema visual humano é frequentemente referido como altamente preparado para extrair informação relevante de padrões de movimento biológico. Nesse sentido, este estudo analisa o efeito de contraste na percepção de velocidade. Os participantes realizaram o julgamento de velocidade numa situação na qual dois point-light walkers simultâneos foram apresentados com diferentes contrastes relativamente ao fundo e com diferentes velocidades de translação. Na Experiência 1, o movimento de translação biológico canônico foi comparado com o movimento de translação rígido, enquanto na Experiência 2 ele foi comparado com o movimento de translação biológico invertido. O padrão biológico canônico apresenta maior taxa de erro, tempos de reação mais elevados e maior vulnerabilidade ao efeito de contraste na percepção da velocidade do que o padrão rígido. No entanto, não foram encontradas diferenças significativas entre o estímulo canônico e o invertido. A Experiência 3 foi implementada com o objetivo de se controlar o papel das pistas posicionais na tarefa de julgamento de velocidade. Os pontos iniciais e finais da trajetória foram combinados de modo a que os point-light walkers mais rápidos e os mais lentos pudessem terminar o ensaio numa posição relativamente mais avançada ou atrasada. Apesar desta variação, o padrão de resultados foi congruente com as observações das Experiências 1 e 2. Aparentemente, os participantes realizaram julgamentos de velocidade factuais, ao invés do uso de pistas espaciais como uma espécie de referência ou comparação de posicionamento. Dado que a percepção dos padrões biológicos foi mais vulnerável aos efeitos de contraste, mas não foi afetada pela familiaridade, este estudo sugere que a percepção de movimento biológico e rígido poderá obedecer às mesmas regras computacionais, pelo menos em tarefas que envolvam padrões em translação e julgamentos de velocidade.The human visual system is often referred to as being highly prepared to extract meaningful information from biological motion patterns. In the present study, the contrast effect on speed perception was analysed. Participants performed a test of speed judgment in which two simultaneous point-light walkers were animated at different translational speeds and contrasts in relation to the background. Standard translational biological motion was compared to rigid translational motion in Experiment 1 and to inverted biological motion in Experiment 2. Higher error rates, reaction times and greater vulnerability to contrast effects on speed perception were found for translational biological motion when compared to rigid motion. No significant differences were found, however, between standard and inverted stimuli. Experiment 3 was implemented in order to control the role of positional cues in speed judgment. The start and finish points of the trajectory were varied so that the faster and slower point-light walkers could finish the trial at a relatively more advanced or more withdrawn position. In spite of the variation of the start and finish points of the trajectories, the pattern of results was still consistent with the findings of Experiments 1 and 2. Participants seemed to perform factual speed judgments instead of using spatial cues as a form of reference or positional matching. Since the perception of biological patterns was more sensitive to contrast effects and not affected by familiarity, it is suggested that perception of biological and rigid motion may follow the same computational rules, at least for tasks involving translational patterns and speed judgment.Fundação para a Ciência e a Tecnologia (FCT

    Distribution-Based Categorization of Classifier Transfer Learning

    Get PDF
    Transfer Learning (TL) aims to transfer knowledge acquired in one problem, the source problem, onto another problem, the target problem, dispensing with the bottom-up construction of the target model. Due to its relevance, TL has gained significant interest in the Machine Learning community since it paves the way to devise intelligent learning models that can easily be tailored to many different applications. As it is natural in a fast evolving area, a wide variety of TL methods, settings and nomenclature have been proposed so far. However, a wide range of works have been reporting different names for the same concepts. This concept and terminology mixture contribute however to obscure the TL field, hindering its proper consideration. In this paper we present a review of the literature on the majority of classification TL methods, and also a distribution-based categorization of TL with a common nomenclature suitable to classification problems. Under this perspective three main TL categories are presented, discussed and illustrated with examples

    Evolution of collective action in adaptive social structures

    Get PDF
    Many problems in nature can be conveniently framed as a problem of evolution of collective cooperative behaviour, often modelled resorting to the tools of evolutionary game theory in well-mixed populations, combined with an appropriate N-person dilemma. Yet, the well-mixed assumption fails to describe the population dynamics whenever individuals have a say in deciding which groups they will participate. Here we propose a simple model in which dynamical group formation is described as a result of a topological evolution of a social network of interactions. We show analytically how evolutionary dynamics under public goods games in finite adaptive networks can be effectively transformed into a N-Person dilemma involving both coordination and co-existence. Such dynamics would be impossible to foresee from more conventional 2-person interactions as well as from descriptions based on infinite, well-mixed populations. Finally, we show how stochastic effects help rendering cooperation viable, promoting polymorphic configurations in which cooperators prevail.This research was supported by FCT-Portugal through grants PTDC/FIS/101248/2008 and PTDC/MAT/122897/2010, by multi-annual funding of CMAF-UL and INESC-ID (under the project PEst-OE/EEI/LA0021/2011) provided by FCT-Portugal. Partial Financial support by the National Science Foundation under Grant No. NSF PHY11-25915 is also gratefully acknowledged

    Effects of motion on time perception

    Get PDF
    To investigate the effect of motion on time perception, participants were asked to perform either a temporal discrimination task or a temporal generalization task while running or standing still on a treadmill. In the temporal discrimination (bisection) task, 10 participants were exposed to two anchor stimuli, a 300-ms Short tone and a 700-ms Long tone, and then classified intermediate durations in terms of their similarity to the anchors. In the temporal generalization task, 10 other participants were exposed to a standard duration (500 ms) and then judged whether or not a series of comparison-durations, ranging from 300 ms to 700 ms, had the same duration as the standard. The results showed that in the temporal bisection task the participants produced more “Long” responses under the dual-task condition (temporal judgments + running) than under the single-task condition (temporal judgments only). In the temporal generalization task, accuracy in the temporal judgments was lower in the dual-task condition than the single-task condition. These results are discussed in the light of dual-task paradigm and of the Scalar Expectancy Theory (SET).Fundação para a Ciência e a Tecnologia (FCT
    corecore