1,721,009 research outputs found
Optical surface metrology for heritage science: proof of concept and critical-constructive discussion
No full textIn the engineering field, surface metrology is a valuable tool codified by international standards that enables the quantitative study of small-scale (down to micrometer) surface features, i.e., the surface topography. However, it is not recognized as a resource in heritage science. In literature we find a large use of qualitative inspection of surface morphology or of single-parameter roughness analysis, which confirms the need and potential of such diagnostics. Reasons of the gap are variegate; artworks are hand-made peculiar targets with heterogeneous surfaces, a multiscale approach is necessary, lack of guidelines and unclear meaning of surface roughness descriptors. We propose a critical-constructive discussion through Proof-of-Concept (POC) applications, on the use of surface metrology based on ISO descriptors. Exemplary case studies include: 1) In situ and in-process monitoring of painting microtexture in a Venetian masterpiece: wide and in-band roughness analysis is performed through the complementary use of amplitude, spatial, and hybrid parameters. 2) Multiscale roughness analysis for treatment monitoring in highly reflective metal artworks, requiring high micrometer accuracy in both depth (0.1 mu m and lateral (5 mu m) directions: surface analysis is performed on scale-limited components to discriminate different surface processes. Surface data are acquired using a prototype of a laser scanning profilometer based on conoscopic holography, with a versatile setup and a surface data pipeline tailored to artwork applications
Evaluating the integration of Thermal Quasi-Reflectography in manuscript imaging diagnostic protocols to improve non-invasive materials investigation
Full text linkMultispectral imaging techniques applied to book heritage are useful to scholars to obtain information on the materials under investigation. The novel introduction of Thermal Quasi-Reflectography (TQR) technique, operating in the medium wave infrared (MWIR) spectral range, can flank conventional diagnostic techniques such as UV-based methods and IR imaging techniques in the 850–1700 nm range on manuscript acquisition. As proof of concept, this work investigates the application of TQR on the Ms. XL (38) palimpsest, known as Vergilius Veronensis, of the Biblioteca Capitolare of Verona. While investigating the manuscript with full-field imaging technique, this work focuses its application to improve the mapping of conservation materials. The manuscript contains several traces of reagents and conservation treatments applied during its conservation history. The study compared the manuscript materials response obtained with TQR with the response collected using UV-induced visible fluorescence (UVL), UV reflected imaging (UVR), and NIR imaging in the 850–1050 nm and 900–1700 nm bands. Being the TQR technique sensitive to surface materials with MWIR reflectance features, it may especially provide more accurate documentation of the restoration history of the object. TQR imaging discriminated non-homogeneities of products in the surface layer thanks to an enhanced MWIR contrast. The TQR image response on manuscript materials should be further investigated and compared to reflectance spectroscopic data. The results of this study demonstrate the added value of TQR imaging for manuscript diagnostics, for which integration of the TQR technique in the standard protocol is desirable
Response to Dr. Thoms letter on “Intraoperative radiotherapy during radical prostatectomy for locally advanced prostate cancer: technical and dosimetric aspects”
No full textGoing 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
Optical micro-profilometry for surface analysis and 3D printed replica of archeological artefacts
No full textpotentialities of the conoscopic holography sensors for surface analysis of archeological artifacts with a micrometric resolution and accurate 3D printing
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
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