1,720,975 research outputs found
STRUMENTI INNOVATIVI DI SUPPORTO ALLA PROGETTAZIONE DI STRUTTURE NAVALI
No full textIn questo lavoro viene presentata una suite di strumenti appositamente sviluppati a supporto delle attività di progettazione destinati alla gestione dei componenti per la realizzazione della struttura di un imbarcazione. Di particolare interesse, dal punto di vista innovativo, risultano essere le metodologie implementate per lo sviluppo di superfici complesse e per il nesting, trattate con maggiore enfasi nella presente memoria.
Tali applicativi sono stati sviluppati e integrati in ambiente Rhinoceros, software per la modellazione di superfici a forma libera molto diffuso nel settore navale, a completamento dei plugin già disponibili.
Gli strumenti sviluppati si sono dimostrati adeguati alle esigenze dei progettisti, garantendo, accanto alla tradizionale flessibilità del software, una notevole riduzione dei tempi di progettazione, degli errori legati all'operatore e dei problemi legati allo scambio dati tra software differenti
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
Hybrid manufacturing of metal framework for full arch dental restoration
No full textPurpose/aim: Selective Laser Melting (SLM) technology
used for the production of a full-arch prosthetic restoration on
implants generates geometry inaccuracies and surface roughness,
which do not fulfill clinical requirements, with biological
consequences on the osteointegration of implants. Modern
approach to Additive Manufacturing (AM) for precision production
integrates SLM and milling techniques in the so-called
hybrid manufacturing process to produce a more accurate
interface to implant.
Materials and methods: The virtual (CAD) model of the
framework was designed as for a full-arch prosthetic rehabilitation
and served as the control of the experiment. Directly
from the framework CAD model, eighteen specimens were
produced by two different manufacturing centers using hybrid
technology, (lab #1 and lab #2). This is a recently introduced
productive process, which integrates the SLM, for the production
of a semi-finished framework, and the milling technique,
for the finishing operation at the interface to implant. Measurements
of the frameworks were made in vitro according
to a metrological approach that uses an opto-mechanical
coordinate measuring machine (OCMM), a CAD-based reconstruction
of actual interface, and a geometric error analysis to
describe manufacturing inaccuracies. Each implant platform
of framework was reduced to its center for the calculation
of the relative (between implants) and absolute distances
(between manufactured framework and its CAD model).
Results:The relative 3D distances between implant platforms
showed a mean error varying from 0 to 25!m for lab
#1 and 0 to 38!m for lab #2; the 3D mean position error of the
implant platforms with respect to the CAD modelwas 8–16!m
for lab #1 and 9–22!mfor lab #2. No statistically significant difference
was registered between the two groups. Considering
both groups, the absolute values of inaccuracy were between
0.011mm and 0.019mm±0.005–0.010mm (SD).
Conclusions:The hybrid technology used for the manufacturing
of the metal framework for an implant-supported
full-arch restoration showed acceptable levels of accuracy,
regardless the specific hybrid system. Using the hybrid technology,
the geometric error generated during the framework
production is lower than 22!m, which is comparable to errors
shown in the literature for direct CAD-CAM manufacturing
from metal blanks
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