1,720,992 research outputs found
Fatigue limit prediction of a compression fork-pin coupling of a front motorbike suspension under fully reversed bending load
No full textA methodology to estimate the adhesive bonding defects and the final releasing moments in conical joints based on the acoustic emissions technique
No full textIt is widely demonstrated in literature that the presence and the density of adhesive bonding defects are difficult to estimate with conventional non destructive testing techniques once the parts are assembled together. For this reason it is very important to set up a new methodology capable of estimating the adhesive bonding defect and the final releasing moment of the assembled joints. The purpose of this paper is to verify the performance of the Acoustic Emissions technique when applied, as a non destructive one, in this field. Our investigation aimed to highlight the good correlation between the density of the adhesive defect (low, medium and high) and the cumulative counts of the Acoustic Emissions
Resistenza a fatica di perni di sterzo per sospensioni motociclistiche soggetti a uno stato di sollecitazione triassiale
No full textPrevisione di vita a fatica del perno dello sterzo di una sospensione anteriore motociclistica
No full textLa rottura del collegamento tra il perno di sterzo ed il trapezio di una sospensione anteriore motociclistica o dell’elemento debole (normalmente il perno) risulta estremamente pericolosa per il conducente e l’eventuale passeggero. La probabilità di rottura deve, dunque, essere mantenuta su valori prossimi a zero per tutto il ciclo di vita del prodotto attraverso una accurata caratterizzazione del materiale nelle diverse condizioni di utilizzo e di sollecitazione dei componenti. La conoscenza della resistenza a fatica del perno di sterzo sollecitato, prevalentemente, dal forzamento nel trapezio e da cicli di flessione in presenza di intagli, anche acuti, risulta di fondamentale importanza per una corretta valutazione del rischio di rottura di tale componente. In questo lavoro si è, dunque, deciso di iniziare la caratterizzazione dinamica di tale elemento partendo dalla condizione di carico a flessione alterna simmetrica in presenza del solo intaglio dovuto al forzamento. Tale situazione prevede una condizione di sollecitazione triassiale composta da una sollecitazione principale di flessione alterna simmetrica e da altre due tensioni principali statiche una circonferenziale ed una radiale. La caratterizzazione del materiale è stata verificata sperimentalmente eseguendo una serie mirata di prove di fatica per la determinazione sia del tratto a termine della curva bi-logaritmica σ-N che del limite di fatica a 106 cicli. In entrambi i casi è stato applicato il criterio di Sines ed il metodo Stair Case modificato (metodo Dixon) al fine di prevedere i limiti di fatica
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
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