1,720,961 research outputs found
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
Dense Stereo Matching for Urban Outdoor Scenes
Full text linkDichtes Stereomatching ist ein aktives Forschungsgebiet im Bereich der Computer Vision. Ziel ist es, Tiefeninformationen aus zwei oder mehr 2D-Bildern einer Szene zu extrahieren. Hierfür wird eine Korrespondenzsuche über alle Pixel der verwendeten Bilder angewandt. Ermittelte Tiefeninformation kann für verschiedene Anwendungen verwendet werden. Beispiele sind die automatisierte Navigation von Robotern und Autos oder die 3D-Rekonstruktion von Gegenständen und Gebäuden. In dieser Arbeit werden wir uns auf dichtes Stereomatching für urbane Outdoor-Bereiche konzentrieren. Der kürzlich publizierte PatchMatch Stereo Ansatz von Bleyer et al. scheint in Hinsicht auf Speicherverbrauch und Skalierbarkeit für hochauflösende Bilder für unsere Zwecke geeignet. Wir starten von dieser Idee und erweitern den Ansatz, um die Verarbeitung von mehr als zwei Bildern zu ermöglichen. Wir testen unseren Algorithmus an verschiedenen Bilddaten im urbanen Außenbereich: Stereobilder aufgenommen von einem fahrenden Auto, Panoramabilder aus städtischen Gebieten, Bildsequenzen von historischen Stätten und Luftbilder. Für die Korrespondenzsuche werden Experimente mit unterschiedlichen Kostenfunktionen durchgeführt. PatchMatch Stereo ist eine lokaler Stereomatching Ansatz, der an jeder Pixelposition eine 3D-Ebene schätzt. Dadurch werden nicht nur Disparitätswerte sondern auch Oberflächennormalen ermittelt. Der PatchMatch Stereo Algorithmus basiert auf einer randomisierten, approximierten Korrespondenzsuche. Zunächst wird für jede Pixelposition eine zufällige Ebene gewählt. Gute Ebenenschätzungen, die niedrige Matching-Kosten aufweisen, werden daraufhin an benachbarte Pixel weitergegeben und in einem iterativen Prozess weiter verfeinert. Wir transformieren den PatchMatch Stereoansatz vom Disparitätsraum in den 3D Szenenraum, um eine direkte Bestimmung von Tiefenwerten zu ermöglichen. Dies ermöglicht zusätzlich das Arbeiten mit nicht-rektifizierten Bildpaaren. Die Abbildung von einem Kamerabild zum anderen wird durch Ebenen-induzierte Homographien ermöglicht. Hierfür wird die geschätzte Ebene (Normale und Tiefenwert) an jeder Pixelposition verwendet. Das Arbeiten im Szenenraum ermöglicht die direkte Verarbeitung von mehr als zwei Bildern, da keine Rektifizierung notwendig ist. Dies führt zum Hauptbeitrag dieser Arbeit: ein Multi-View Stereo Matching-Ansatz. Die Verwendung von mehr als zwei Bildern erleichtert die Handhabung von teilweise verdeckten Bildbereichen und führt dadurch zu robusteren Ergebnissen. Unser Ansatz wird quantitativ auf bestehenden Benchmarks für 2-View und Multi-View Bildsequenzen ausgewertet. Die Ergebnisse werden des Weiteren mit anderen State-of-the-Art Stereomatching Methoden verglichen.Dense stereo matching is an active research topic in the area of Computer Vision. Depth information is extracted from a dense correspondence search between two or more images of the same scene, taken from different camera positions. Extracted depth information can be used for various applications such as robotic navigation, automated driving or 3D reconstruction of objects and buildings. In this work we will focus on dense stereo matching for urban outdoor environments. We start from the recently published PatchMatch Stereo approach by Bleyer et al. since it seems suitable for our purpose in terms of memory consumption and scalability for high resolution images. We further extend their idea to multi-view stereo. Our algorithm is tested on different urban outdoor image sets, including image pairs from cameras mounted on a car, panoramic images of urban areas as well as multi-view data from historic sites and aerial image data. For the correspondence search, experiments with different cost functions are performed. PatchMatch Stereo is a local stereo matching approach that estimates a 3D plane at each pixel position, hence, extracting not only disparity values but also surface normals. The PatchMatch Stereo algorithm is based on a randomized approximate correspondence search. Initially a random plane is selected for each pixel position. Good plane estimates are then propagated to neighboring pixels and further refined in an iterative process. We transform the PatchMatch Stereo approach to scene space in order to directly estimate depth values and work with non-rectified images. Mapping from one image to another is facilitated by plane induced homographies, utilizing the estimated planes (normal and depth) at each pixel position. Processing in scene space allows us to directly combine multiple images. The major contribution of our work is a multi-view stereo matching approach. The use of more than two images facilitates the handling of partially occluded image regions and therefore leads to more robust results. Our approach is quantitatively evaluated on existing benchmark data for two-view and multi-view image sequences. Results are compared with reported values of state-of-the-art stereo matching methods
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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