1,720,957 research outputs found
Interference Level Estimation for a Blind Source Separation in Document Restoration
No full textWe deal with the problem of blind separation of the components, in particular for documents corrupted by bleed-through and show-through. So, we analyze a regularization technique, which estimates the original sources, the interference levels and the blur operators. We treat the estimate of the interference levels, given the original sources and the blur operators. In particular, we investigate several GNC-type algorithms for minimizing the energy function. In the experimental results, we find which algorithm gives more precise estimates of the interference levels
A Blind Source Separation Technique for Document Restoration Based on Image Discrete Derivative
No full textIn this paper we study a Blind Source Separation (BSS) problem, and in particular we deal with document restoration. We consider the classical linear model. To this aim, we analyze the derivatives of the images instead of the intensity levels. Thus, we establish non-overlapping constraints on document sources. Moreover, we impose that the rows of the mixture matrices of the sources have sum equal to 1, in order to keep equal the lightnesses of the estimated sources and those of the data. Here we give a technique which uses the symmetric factorization, whose goodness is tested by the experimental results
An Edge-Preserving Regularization Model for the Demosaicing of Noisy Color Images
No full textThis paper proposes an edge-preserving regularization technique to solve the color image demosaicing problem in the
realistic case of noisy data. We enforce intra-channel local smoothness of the intensity (low-frequency components) and
inter-channel local similarity of the depth of object borders and textures (high-frequency components). Discontinuities of
both the low-frequency and high-frequency components are accounted for implicitly, i.e., through suitable functions of the
proper derivatives. For the treatment of even the finest image details, derivatives of first, second, and third orders are considered.
The solution to the demosaicing problem is defined as theminimizer of an energy function, accounting for all these constraints
plus a data fidelity term. This non-convex energy is minimized via an iterative deterministic algorithm, applied to a family of
approximating functions, each implicitly referring to geometrically consistent image edges. Our method is general because
it does not refer to any specific color filter array. However, to allow quantitative comparisons with other published results,
we tested it in the case of the Bayer CFA and on the Kodak 24-image dataset, the McMaster (IMAX) 18-image dataset,
the Microsoft Demosaicing Canon 57-image dataset, and the Microsoft Demosaicing Panasonic 500-image dataset. The
comparisons with some of the most recent demosaicing algorithms show the good performance of our method in both the
noiseless and noisy cases
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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