1,720,980 research outputs found
Rilievo, posizionamento geodetico, elaborazione grafica nelle campagne 2002-2003.
No full textBreve resoconto delle attivita' di rilievo presso lo scavo archeologico della Bastia di Onigo, Treviso campagne 2002-2003
A volumetric approach for 3D surface reconstruction
No full textIn the last years, measuring sensors like the TOF or optical-based terrestrial laser scanners have been more and more increasingly used, given their capability to acquire the 3D geometry of the surveyed object. Applications for these systems span among different fields, such as industry, medicine, land management, heritage and VR environments. Regardless long-range or close-range laser scanner was employed, two following steps need to be performed in order to reconstruct the object shape: range image registration and integration. The former allow for “tailoring” together the acquired point clouds, representing a “view” of the object surface as sampled by the laser sensor. Then, after all views have been aligned each other, a unique representation of the object surface is generated through the integration of those 3D views. At this stage several factors prevent from building the descriptive surface by simple connection of the range images: non-uniform density sampling, measuring and registration errors.
To solve for such modeling issues, a volumetric approach has been devised for the generation of a mesh, i.e to create a surface representation from range data acquired by an optical triangulation laser scanner.
The developed method is based on the “consensus surface” concept introduced by Wheeler, Sato and Ikeuchi, by which some kind of errors of the range images can be better identified and corrected. Then it has been refined by integration with the so-called “Marching cubes” algorithm, a well used surface generation procedure in the field of Computer Graphics. Finally, the proposed method has been completed with the development of a tool for hole-filling , though its application is limited to little holes with enough regular edges. Pros and cons along with the results of our meshing algorithm, applied to a little statue, will be presented as well
Dati RGB e Laser Scanner per la Modellazione di Piccoli Oggetti Complessi
No full textLa realizzazione di modelli 3D digitali di beni architettonici o storici e la relativa visualizzazione al computer è oggi uno dei campi di ricerca a cui viene rivolto maggior interesse per le innumerevoli applicazioni pratiche che possono derivare da questi studi. Ancor oggi rimane incerto il problema fondamentale di come si possa unire al dato 3D, proveniente dal laser scanner, l’informazione di colore dell’oggetto rappresentato. Sebbene esistano in commercio alcuni software dedicati alla texturizzazione del modello 3D a partire da immagini digitali, i risultati non sempre risultano soddisfacenti, soprattutto nel caso di geometrie particolarmente complesse. Mentre infatti nel caso di scansioni di oggetti con sviluppo prevalentemente piano si ottengono buoni risultati, superfici caratterizzate da elevati valori di curvatura favoriscono l’insorgenza di discontinuità e imperfezioni nella texture finale inaccettabili. In questo articolo si vogliono esporre i risultati di un’esperienza condotta in collaborazione tra il Cirgeo (Centro Interdip. di Ricerca dell’Università di Padova) e l’ITC (Istituto Trentino di Cultura) nell’ambito della produzione di modelli 3D, con texture, relativi ad oggetti di piccole dimensioni, mediante integrazione di tecniche laser scanner e fotogrammetria digitale applicata ad immagini ad alta risoluzione. I risultati ottenuti nella riproduzione virtuale degli oggetti considerati sembrano soddisfacenti dal punto di vista delle texture, la cui qualità appare comparabile se non superiore a quanto prodotto dai software di uso commerciale
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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