1,720,960 research outputs found
Metodologie di previsione della manovrabilit? delle navi. Parte I: Il meccanismo del moto piano.
No full textThe present paper is the first one od a series of articles devoted to the predicting methodologies of ship manoeuvrability. Particularly, in the next numbers it will be published further three papers concerning the following themes: - the manoeuvring simulators - the sea trials - the free running model tests In the present work the Planar Motion Mechanism (PMM) will be introduced: it allows, carrying out suitable tests in linear towing tank, the determination of the necessary hydrodynamic coefficients to effect prediction on the ship manoeuvrability. After a brief excursus on the PMM principle, the main captive model test will be introduced to the scope to predict the ship manoeuvrability. In the following, the main characteristics of the PMM recently installed at the INSEAN in Rome will be illustrated. Finally, the guidelines dictated by the "Manoeuvring Captive Model Test Procedure" introduced during the 23rd ITTC (International Towing Tank Conference) held in Venice will be discussed. Such a procedure foresees, in the preliminary test phase, the choice of a series of parameters, for the execution of the harmonic captive model tests, through the application of some empirical-theoretical formulas. The different achievable formulations will be critically introduced, keeping in mind the indications given by the different researchers devoted to the manoeuvrability and mathematical modelling studies.Il presente lavoro vuole costituire il primo di una serie di articoli dedicati alle metodologie di previsione dellamanovrabilit? delle navi. In particolare, nei prossimi numeri si cercher? di pubblicare ulteriori tre lavori riguardanti le seguenti tematiche: - i simulatori di manovra - le prove in mare - le prove con modello libero Nel presente lavoro viene presentato il meccanismo del moto piano PMM (Planar Motion Mechanism) che consente mediante lo svolgimento di adeguate prove in vasca navale rettilinea, la determinazione dei coefficienti idrodinamici necessari per effettuare previsioni sulla manovrabilit? di una nave. Dopo un breve excursus sul principio di funzionamento del PMM, verranno presentate le principali tecniche sperimentali realizzate con modello vincolato, finalizzate alla previsione delle capacit? di governo di una nave. Di seguito, sar? illustrato il PMM da poco installato prello l\u27INSEAN - IStituto Nazionale per Studi ed Esperienze di Architettura Navale di Roma. Infine verranno riportate le linee guida dettate dalla procedura per lo svolgimento delle prove di manovrabilit? con modello vincolato "Manoeuvring - Captive Model Tests Procedure", presentata durante la 23rd ITTC (International Towing Tank Conference) tenutasi a Venezia nel settembre 2002. Tale procedura prevede, nella fase preliminare delle prove, la scelta di una serie di grandezze pre l\u27effettuazione delle prove in vasca, da realizzarsi mediante l\u27applicazione di alcune formule teorico-empiriche. Le differenti formulazioni possibili saranno presentate e discusse in maniera critica, tenendo presente le indicazioni emerse dai diversi studiosi che si sono dedicati alle problematiche di manovrabilit? e modellazione matematica di fenomeni fisici
Metodologie di Previsione della Manovrabilità delle Navi - Parte II: Le Prove con Modello Libero
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
- …
