1,720,984 research outputs found
3D Virtual Modelling of a Gothic Stained-Glass Panel.
Full text linkThe paper illustrates laser scanning methodology applied to the study of a gothic stained-glass window: the work can help understanding how glass objects are measured by laser scanner, conforming to more parameters. A glass window from King’s Chapel, Cambridge (UK) was modelled: a vertical ensemble, divided into more parts, made of glass, coloured during its realisation or coloured before being placed on the wall. Thus, a different sensitivity to laser beam is expected from glass. The acquisition was performed using Konica Minolta Vivid 910, with a 5 x 8 scan matrix. Registration via ICP algorithm was carried in 8 horizontal stripes. Scans seem to be quite homogeneous, except some lacunas, probably depending on a “brownout-effect” induced by the presence of stain structure, partly obscuring glass surface. Otherwise they could be depending on local condition of glass, causing loose of signal from the surface. Some details show a particular noise in the acquisition, probably caused by an outdoor metal scaffolding, especially in more transparent areas. A comparison with the acquisition of an object protected by a glass showcase is illustrated too, to study the response of glass material. It was argued that glass painted with non covering colours is more sensitive to such object while covering colours (or coloured glass) “stop” laser beam and give no noise. Besides with painted sheets, a 3D laser scanning model can give a sub-millimetrical mapping with the thickness of colour layers: thus, noise induced by the metal scaffolding can be evaluated too
Benzo(c)thiophene derivatives. IV. Synthesis and disproportionation of 1,1',3,3'-tetrahydro-1,1'-dimethoxycarbonyl-1,1'-dibenzo(c)thiophene
No full textHigh Resolution Morphometric Reconstruction of Multimaterial Tiles of an Ancient Mosaic.
Full text linkActually scientific research in the human disciplines has been looking with growing interest towards virtual reconstruction of cultural heritage objects and handiworks, and in particular towards those which are dismembered or broken, with the specific aim of virtual anastylosis and virtual conservation of them. In this paper, we present the virtual reconstruction of a mosaic fragment, from the Abbey of Santa Giustina, Padova, Italy: the work, concerning the first part of a larger project of digital anastylosis of the mosaic itself, investigates the geometry of the fragment from single tesserae of different tiles in order to study the single mosaic structure and to reconstruct the whole mosaic. This work shows the laser scanner acquisition of a multi-material objects, requiring a good planning of the scanning phase, underlines all main problems in the acquisition of high reflectance materials and stresses out the possibility to reconstruct of a whole model, allowing to measure all metrical features of tiles in a virtual space (size, volume, depth of alteration strata...) without any invasive contact
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
Il disco votivo di San Pietro di Rosà . Approfondimenti tecnici
No full textSu reperti archeologici sono state, da tempo, applicate metodologie di Reverse Engineering allo scopo di acquisire e classificare le superfici degli stessi. Le applicazioni spaziano dalla catalogazione dei reperti allo sviluppo di tecniche per il restauro virtuale; quest’ultimo approccio consente di simulare più interventi di restauro senza intaccare minimamente il reperto stesso ed inoltre consente di ricostruire, virtualmente, eventuali parti mancanti.
In questo lavoro, si presenta l’applicazione della scansione laser tri-dimensionale ad un disco votivo in lamina di bronzo. In particolare, si è acquisita la superficie tri-dimensionale del reperto allo scopo di migliorare la comprensione di particolari incisi, dove il tempo e l’incuria avevano modificato localmente la superficie stessa deformandola e rendendo difficile, ove non possibile, l’identificazione e la lettura di alcuni particolari.
Il disco votivo da San Pietro in Rosà (VI) è stato analizzato presso i laboratori di ricerca del Dipartimento di Architettura, Urbanistica e Rilevamento dell’Università degli Studi di Padova, utilizzando, principalmente, una macchina CMM a scansione laser ed elaborando le immagini così acquisite con tecniche di Image Processing.
Nello specifico, è proprio l’integrazione tra le metodologie di acquisizione (scansione laser 3D) e di analisi (filtraggio dei dati e manipolazione dei fattori di scala) che ha consentito una migliore lettura del reperto nel suo insieme e nei particolari che lo caratterizzano.
Il disco ha un diametro di 19.1 cm ed è decorato ad incisione e a sbalzo su tutta la superficie. In Fig. 1 è riportata un’immagine acquisita nel visibile ed in digitale con evidenziati due particolari oggetto di un’analisi più approfondita
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
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