278 research outputs found

    A Graphical Humor Ontology for Contemporary Cultural Heritage Access

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    Humor is a multifaceted communication phenomenon that has been approached from different perspectives in existing research studies. Such heterogeneity of views poses a challenge to the creation of metadata records for digital humor assets, if rich interpretive and descriptive sentences are desired for the construction of semantic access interfaces. Ontologies in the context of Semantic Web research provide the appropriate flexible representational framework for describing the many aspects and interpretations of digital humor artefacts. This paper reports the initial design of an ontology of humor artefacts engineered as part of a project that deals with semantic access to contemporary Spanish graphical humor. The main ontological commitments adopted – semantic frames and humor technique applications - are described, along with the annotation technique used and some illustrative examples of the richness that the approach provides to browsing interfaces

    Thickness dependent magnetic anisotropy of ultrathin LCMO epitaxial thin films

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    The magnetic properties of La0.7Ca0.3MnO3 (LCMO) manganite thin films were studied with magnetometry and ferromagnetic resonance as a function of film thickness. They maintain the colossal magnetoresistance behavior with a pronounced metal-insulator transition around 150-200 K, except for the very thinnest films studied (3 nm). Nevertheless, LCMO films as thin as 3 nm remain ferromagnetic, without a decrease in saturation magnetization, indicating an absence of dead-layers, although below approx. 6 nm the films remain insulating at low temperature. Magnetization hysteresis loops reveal that the magnetic easy axes lie in the plane of the film for thicknesses in the range of 4-15 nm. Ferromagnetic resonance studies confirm that the easy axes are in-plane, and find a biaxial symmetry in-plane with two, perpendicular easy axes. The directions of the easy axes with respect to the crystallographic directions of the cubic SrTiO3 substrate differ by 45 degrees in 4 nm and 15 nm thick LCMO films.Comment: Presented at Intermag conference (Madrid, 2008). Accepted for publication in IEEE Transactions on Magnetic

    Spin diffusion versus proximity effect at ferromagnet/superconductor La_(0.7)Ca_(0.3)MnO_(3)/YBa_(2)Cu_(3)O_(7-δ) interfaces

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    We report on the interplay between magnetism and superconductivity in La_(0.7)Ca_(0.3)MnO_(3)/YBa_(2)Cu_(3)O_(7) structures. We have grown heterostructures (bilayers and trilayers) with a constant thickness of the ferromagnetic layer of 40 unit cells (15 nm) and changing the thickness of the superconductor between 1 (1.2 nm) and 40 unit cells (48 nm). The critical temperature of the bilayers decreases when the thickness of the superconductor is reduced below 10 unit cells, thus providing an estimate of the length scale of superconductivity suppression by spin-polarized quasiparticles in YBa_(2)Cu_(3)O_(7-δ) (YBCO) of 10 nm, much larger than the coherence length. For thickness of the YBCO layer smaller than 4 unit cells; a second mechanism of superconductivity depression comes into play, probably related to the ferromagnetic/superconducting proximity effect. The relative importance in depressing the critical temperature of intrinsic mechanisms (quasiparticle diffusion and proximity effect) and extrinsic ones (intralayer disorder, interface roughness, or reduced dimensionality of ultrathin layers) is discussed
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