1,720,973 research outputs found
Liposome composition of colistin for intravenous, oral, and cutaneous therapheutic use, and process for its preparation
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Non-isometric colour similarity
No full textThis paper presents the findings obtained in an experimental study of metric underlying the perceptual colour space. Previous studies evidenced that, in tasks of evaluation of colour similarity, the subjects don't refer to the most general category of “colour”, but rather rely on the introduction of subordinate categories containing all variations of a colour. Besides, categories related to different colours can sometimes overlap. This forces to conclude that perception of colour variations is not isometric, but is rather weighed in different ways for different colours.
In order to detect the metric of colour space we performed an experiment with multiple conditions within the subjects, designed to determine the form of the function that ties the independent variable (tonality of colour) with the dependent variable (similarity judgement). To each subject we presented simultaneously a pair of images, the target one and another differing from the target only for its colour (a suitable perturbation of the tonality). The subject task was to rate the similarity of the second image with the target. The frequency distribution of similarity judgments for each colour gave a qualitative description of how the different colours are represented at the cognitive level. We applied to the observed frequencies a unidimensional scaling procedure to obtain a precise measure of the distance between the variation steps for each colour. We were allowed to choose a single dimension because we limited the study only to the variation of tonality. The scaling was applied separately to each colour scale.
The results showed that different colours were associated to different measure scales. Besides, once chosen a particular colour, its measure scale itself was depending on the direction of variation chosen for its tonality during the experimental presentation. We can conclude that the geometry of colour space looks very complicated and not reducible to familiar mathematical concepts
Perception of an underwater structure for inspection and guidance purpose
No full textThe paper concerns the detection and the real-time tracking of submarine The problem involves both perception and robotics, in that sensory-motion data are to be acquired and dynamically used for subsequent actions by the system. The basic processing concerns the extraction of the pipe contours which are returned as two straight lines. Motion effects on acquired images have been reduced using a Kalman filter for integrating multiple measurements over time. The filter, positioned at the output of the image processing system improves the precision in the computation of the straight line equations with a little overload. This work is originated from the interest of Snamprogetti in enhancing the level of automation in submarine pipeline inspectio
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
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