1,721,223 research outputs found
Migliore M. Ch. et Pagani S. (éd.), Inferni Temporanei – Visioni dell’Aldila. Dall’Estremo-Oriente all’Estremo Occidente. Rome, Carocci Editore, 2011,
No full textLory Pierre. Migliore M. Ch. et Pagani S. (éd.), Inferni Temporanei – Visioni dell’Aldila. Dall’Estremo-Oriente all’Estremo Occidente. Rome, Carocci Editore, 2011,. In: Bulletin critique des annales islamologiques, n°27, 2012. p. 24
Algorithms for linear time reconstruction by discrete tomography
No full textWe present an algorithm that for any given rectangular grid A∈Z2 and set of directions D computes in linear time the values of any function f:A→R outside the convex hull of the union of the switching domains from its line sums in the directions of D. Moreover, the algorithm reconstructs f completely if there are no switching domains. We present a simpler algorithm in case the directions satisfy some monotonicity condition. Finally, for given A we propose how to choose the set D so that only a small number of directions is needed to reconstruct any f from its line sums in the directions of D
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ambiguous reconstructions of hv-convex polyominoes
No full textThe core problem of discrete tomography, i.e., the faithful reconstruction of an unknown discrete object from projections along a given set of directions, is ill-posed in general. When further constraints are imposed on the object or on the employed directions, uniqueness of the reconstruction can be obtained. It is the case, for example, of convex lattice sets in Z2, for which a theorem by Gardner and Gritzmann assures the faithful reconstruction when suitable sets of directions are considered. It was conjectured that a similar result holds for the class of hv-convex polyominoes. In this paper we are concerned with this conjecture, providing new 4-tuples of discrete directions that do not lead to a unique reconstruction of hv-convex polyominoes, underlining the relevant structural difference with the class of convex sets. Our result is based on the recursive definition of new hv-convex switching components on discrete sets along four directions
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Universal Solution Manifold Networks (USM-Nets): Non-Intrusive Mesh-Free Surrogate Models for Problems in Variable Domains
Full text linkWe introduce universal solution manifold network (USM-Net), a novel surrogate model, based on artificial neural networks (ANNs), which applies to differential problems whose solution depends on physical and geometrical parameters. We employ a mesh-less architecture, thus overcoming the limitations associated with image segmentation and mesh generation required by traditional discretization methods. Our method encodes geometrical variability through scalar landmarks, such as coordinates of points of interest. In biomedical applications, these landmarks can be inexpensively processed from clinical images. We present proof-of-concept results obtained with a data-driven loss function based on simulation data. Nonetheless, our framework is non-intrusive and modular, as we can modify the loss by considering additional constraints, thus leveraging available physical knowledge. Our approach also accommodates a universal coordinate system, which supports the USM-Net in learning the correspondence between points belonging to different geometries, boosting prediction accuracy on unobserved geometries. Finally, we present two numerical test cases in computational fluid dynamics involving variable Reynolds numbers as well as computational domains of variable shape. The results show that our method allows for inexpensive but accurate approximations of velocity and pressure, avoiding computationally expensive image segmentation, mesh generation, or re-training for every new instance of physical parameters and shape of the domain
Erratum to “A rounding theorem for unique binary tomographic reconstruction” [Discrete Appl. Math. 268 (2019) 54–69, (S0166218X19302562), (10.1016/j.dam.2019.05.005)]
No full textWe correct an error occurred in Lemma 10, and a couple of typos in the following paper P. Dulio, S.M.C. Pagani A rounding theorem for unique binary tomographic reconstruction, Discrete Appl. Math. 268 (2019) 54–69. The corrections do not alter anyone of the obtained results
Trichromatic Colour Vision: The Choice between Red and Green Colour in Chlorocebus aethiops
No full textTwo main theories try to explain the nature of the selective pressure that led to trichromatic colour vision in primates. The foraging hypothesis suggests that colour discrimination is linked to the detection and selection of food, whereas another hypothesis connects trichromacy to the perception of skin colour signaling in a socio-sexual context. The goal of this study was to investigate which hypothesis could be the most plausible to explain the evolution of trichromatic colour vision. At this purpose the colour preference of a colony of vervet monkeys (Chlorocebus aethiops) hosted at Parco Natura Viva – Garda Zoological Park was investigated. Couples of red and green bags containing the same hidden reward were placed in the outdoor enclosure of vervet monkeys and their choice between red and green objects was recorded in order to investigate the effects of colour cues on object preference in the social context. Moreover, the hand used to retrieve objects was recorded to assess a possible relation between hand preference and colour choices. Results indicate that choices do not seem to be based on object colour. However, monkeys showed a significant right-hand preference to retrieve green objects. In conclusion, these observations seem not to support the foraging hypothesis of the origin of colour vision. Therefore, the role of intraspecific socio-sexual communication could be more plausible for the evolution of trichromacy, but this aspect should be better investigate in future studies
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