28,413 research outputs found

    Color Engineering of Silicon Nitride Surfaces to Characterize the Polydopamine Refractive Index

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    A simple methodology to generate polydopamine (PDA) surfaces featured with color due to thin-film interference phenomena is presented. It is based on depositing ultra-thin films of polydopamine on a Si/Si 3 N 4 wafer that exhibits an interferential reflectance maximum right at the visible/UV boundary (∼400 nm). Therefore, a small deposit of PDA modifies the optical path, in such manner that the wavelength of the maximum of reflectance red shifts. Because the human eye is very sensitive to any change of the light spectral distribution at the visible region, very small film thickness changes (∼30 nm) are enough to notably modify the perceived color. Consequently, a controlled deposit of PDA, tune the color along the whole visible spectrum. Additionally, good quality of PDA deposits allowed us to determine the refractive index of polydopamine by ellipsometry spectroscopy. This data can be crucial in confocal skin microscopic techniques, presently used in diagnosis of skin tumors.Fil: Vega Moreno, Milena Amparo. Universidad de Salamanca; EspañaFil: Martín del Valle, Eva M.. Universidad de Salamanca; EspañaFil: Perez, Maximiliano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Haedo; ArgentinaFil: Pecharromán, Carlos. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia de los Materiales de Barcelona; EspañaFil: Marcelo, Gema. Universidad de Salamanca; Españ

    Examples of Artificial Perceptions in Optical Character Recognition and Iris Recognition

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    This paper assumes the hypothesis that human learning is perception based, and consequently, the learning process and perceptions should not be represented and investigated independently or modeled in different simulation spaces. In order to keep the analogy between the artificial and human learning, the former is assumed here as being based on the artificial perception. Hence, instead of choosing to apply or develop a Computational Theory of (human) Perceptions, we choose to mirror the human perceptions in a numeric (computational) space as artificial perceptions and to analyze the interdependence between artificial learning and artificial perception in the same numeric space, using one of the simplest tools of Artificial Intelligence and Soft Computing, namely the perceptrons. As practical applications, we choose to work around two examples: Optical Character Recognition and Iris Recognition. In both cases a simple Turing test shows that artificial perceptions of the difference between two characters and between two irides are fuzzy, whereas the corresponding human perceptions are, in fact, crisp.Comment: 5th Int. Conf. on Soft Computing and Applications (Szeged, HU), 22-24 Aug 201

    Social Objects

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    One reason for the renewed interest in Austrian philosophy, and especially in the work of Brentano and his followers, turns on the fact that analytic philosophers have become once again interested in the traditional problems of metaphysics. It was Brentano, Husserl, and the philosophers and psychologists whom they influenced, who drew attention to the thorny problem of intentionality, the problem of giving an account of the relation between acts and objects or, more generally, between the psychological environments of cognitive subjects and the different sorts of external (physical, geographical, social) environments which they inhabit. The present essay addresses this environmental version of the problem of intentionality. It draws not only on the work of Husserl and Scheler but also on the Gestalt psychological writings of Kurt Koffka and Kurt Lewin. It considers the influential subjective idealist theory of animal environments put forward by J. von Uexküll and contrasts this with a realist theory of organism-environment interaction based on the work of the ecological psychologists J. J. Gibson and Roger Barker. This realist theory is then exploited as a basis for an ontology of social objects of a range of different sorts. (This is the English original of the French translation.
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