1,721,296 research outputs found
METAVERSO - Control remoto del mundo físico
No full textParra Rodriguez, Jaime; director de proyecto: Reinoso Peinado, Antonio José2022-2023Grado en Ingeniería InformáticaEscuela Politécnica Superio
Analysis of symmetric patterns in images
No full textThe computational detection of symmetry is of large importance not only to model human vision, but to leverage the structural information it carries. Due to the complexity of the problem, researchers tackle automated symmetry detection as a search rather than a model-based approach in most of the cases.The detection of symmetry has found several applications including segmentation, gait analysis, interest-point detection, saliency models and human pose tracking amongst others. Despite the variety of approaches, the detection of symmetry is still an open area of research. In this thesis, symmetry perception and detection algorithms are directly related to Marr’s stages of vision.Feature-based symmetry detection methods tend to over-perform other approaches, nevertheless, they are computationally demanding. These are reliant on the presence of matched pairs of features, therefore they benefit from the abundance of such points; this implies that a trade-off between performance and computation time must be found. Here, the detection of large sets of features and the computation time for feature based symmetry detection algorithms are addressed.A new procedure for feature based symmetry detection is introduced. We make use of the efficient binary descriptors, allowing for a drastic reduction on the computation times. Moreover, we use a density-based approach to detect axes of symmetry in the parameter space; this augments resolution and provides more flexibility for the detection.Two new feature detection methods are presented. The Locally Contrasting Keypoints (LOCKY) is a novel blob-detector aimed at reducing computation times. The detection is achieved with an innovative non-deterministic low-level operator called the Brightness Clustering Transform (BCT). The BCT can be thought as a coarse-to-fine search through scale spaces for the true derivative of the image; it also mimics trans-saccadic perception of human vision. LOCKY shows good robustness to image transformations included in the Oxford affine-covariant regions dataset, and is amongst the fastest affine-covariant feature detectors.Unsupervised representation learning enables computers to learn visual cues from unlabelled data, obviating the need for hand-crafted feature models. The second feature detector is a novel technique to find rotation-invariant structures using an unsupervised representation learning strategy. This is accomplished by mapping image-patches into a rotation-invariant space built with the Bessel-Fourier moments. We analyse this space in terms of the symmetry of features and categorise them into three groups, non-symmetric, symmetric and composite-symmetric. Feature-maps are created by comparing patches in an image against the feature models, non-maxima suppression is performed afterwards. The detected features show very competitive results on repeatability tests compared with state of the art detectors. Moreover our approach can recognise multiple structures therefore, the user can substantially increase the amount of detected features in a controlled manner.Using the methods presented in this thesis, symmetry detection computation times are drastically reduced by approximately ten-fold compared to other state of the art approaches. The use unsupervised learning for the rotation-invariant detection of structures,also yields an improvement on the symmetry detection performance measured against the state of the art
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
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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