1,721,053 research outputs found
A review of experimental and numerical activities on composites crashworthiness performed at the University of Bologna
No full textThe paper presents a summary of experimental and simulation activities carried out by Masterlab research group at the University of Bologna in the last decade. Activities started in 2004 with laboratory set-up and with collaborations on the testing of flat specimen, which led to the development of a geometry for self-supporting corrugated specimen. On the latter geometry, a study on edgewise and internal triggering solutions focused on their effect on crushing response and design implications for typical structures. Lastly, a test campaign is implemented to calibrate a Continuum Damage Mechanics model into the FE code Pam-Crash, validated on all previous experimental activities
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
Utilizzo di Materiali a Memoria di Forma per il Restauro di Superfici Musive ed il Consolidamento di Paramenti Murari
No full textTra le numerose applicazioni della classe di materiali definiti Shape Memory Alloys (SMA), è particolarmente recente quella nel campo del restauro di opere d’arte [1]. Nella prima parte del presente lavoro è stato studiato il comportamento, sia attraverso simulazioni numeriche, sia mediante test sperimentali, di un dispositivo a memoria di forma in nickel-titanio (NiTiNOL), progettato per essere utilizzato come ancoraggio nel caso di superfici musive che presentino distacchi dalla parete o fra gli strati dell’intonaco di supporto. Gli apparati in esame sono stati discretizzati all’interno di un codice di calcolo agli elementi finiti, utilizzando, per la definizione del materiale, delle curve tensione-deformazione ricavate sperimentalmente. Tali curve, oltrechè modificarsi notevolmente al variare della temperatura, presentano un particolare comportamento non lineare. I risultati delle analisi numeriche hanno confermato e precisato la validità delle analisi precedenti effettuate in sede di definizione delle caratteristiche del dispositivo [1, 2]. Gli esperimenti di laboratorio, svolti parallelamente alle simulazioni, hanno permesso di ottimizzare il modello utilizzato, di verificare l’affidabilità di questo dispositivo di ancoraggio, di ipotizzare ulteriori miglioramenti della sua geometria ed, infine, di progettare altri dispositivi da impiegare in contesti differenti da quello delle pareti musive. In particolare, nella seconda parte del lavoro vengono sinteticamente descritte varie applicazioni in SMA per il cantiere di restauro delle celebri botteghe di via dell’Abbondanza a Pompei, come i) dispositivi per l’ancoraggio di strati di intonaco ed ii) in blocchi lapidei e iii) giunti per la movimentazione di lastre in policarbonato
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
Validation of a Continuum Damage Model for predicting the axial-crush response of CFRP composite material
No full textIn this work, the validation of the Finite Element (FE) analysis code PAM-Crash for the simulation of crashworthy composite structures is proposed. The investigation follows the principles of the Building Block Approach (BBA): FE analyses are supported at an increasing level of geometrical complexity by experimental campaigns. The investigation starts with multiple sets of coupon level testing on carbon fiber-epoxy UD material, followed by the quasi-static axial crushing of a self-supporting specimen. Tests performed include: tension, compression, in-plane shear and delamination modes I and II. A continuum damage mechanics (CDM) model is implemented starting from elementary load cases, then scaling up to the self-supporting specimens. The phenomenological meso-model for the intra-ply post-failure behaviour is based on the studies of Ladevèze, as later revised by Johnson and Pickett. In addition, a cohesive zone model is used to account for the delamination phenomena. Influence of different simulation strategies and simulation settings are discussed within the body of this work: a model comprising a single multilayered shell element, a staked set of shells representing the single constituent ply connected by inter-ply cohesive elements, and lastly, an intermediate solution using sub laminate groups. Influence of mesh size, friction coefficients and crushing velocity are also discussed. Results show that the CDM model alone is not able to correctly simulate the complex load cases, but calibration strategies of the material card are necessary to fit the experimental data. The required manual tuning limits the predictive quality of the model, as the characterisation effort alone is unable to describe the energy absorption characteristic of the different physical phenomena occurring during crushing. In addition, due to the different features of the proposed numerical approach, the contribution on Specific Energy Absorption (SEA) of the different crushing modes is discussed. A sensitivity analysis of different card parameters on simulation results is finally discussed in order to propose a framework for future investigation
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