1,721,004 research outputs found
Sailing dinghy hydrodynamic resistance by experimental and numerical assessments
No full textHull forms of high-performance sailing dinghies are very interesting for yacht designers. After a long period in
which the attention has been focused on one-design boats, in recent years a few exciting restricted classes such as
International Moth, International 14', 18’ Skiff and Class A catamaran become recognized in several countries
and led to interesting advances in high-performance yacht design.
“1001VELAcup R3” class is two people racing dinghy designed according to a box rule with limitation on LOA
and Bmax and total sail area. The boats must be designed and built by students of European Universities and race
yearly in Italy.
This paper focuses on two best-ranked boats “LED” from the University of Palermo and “TryAgain” managed
by the University of Naples but designed by the University of Roma3 team. These boats were definitely superior
as regard motion resistance when tested without appendages during 2017 MIDWINTER INDOOR RACE and,
although very different in main section shape, had comparable performances.
The observed behaviours and the availability of experimental data suggested a suitable numerical approach
and a fair comparison between experimental and numerical results is presented
A new systematic series of foil sections with parallel sides
Full text linkParallel-sided foil sections are used for centerboards and rudders in sailing dinghy classes
and also for struts placed in a fluid flow. The objective of this work is to create a systematic series
of parallel-sided sections to be used under different conditions, with an emphasis on the sailing
dinghies 470, 420 and Optimist. The loss, and surprisingly the gain, in performance relative to 4-digit
NACA sections are also investigated. A 2D Reynolds-averaged Navier–Stokes solver is used with
the k-ω SST turbulence model and the gamma transition criterion. A verification study is carried
out based on four grids of systematically varied density, and results compared with experimental
data on a NACA 64-006 section. The parallel-sided sections are modeled with rational Bézier curves
whose geometrical parameters permit to link the shape of the profile to physical variables, which are
systematically varied. Three Reynolds numbers and two angles of attack are investigated. Systematic
plots show the influence of the trailing edge angle and nose radius for the different section families,
and the optimum combination is presented in a table. Physical explanations of the trends, and of the
exceptions, are given in the paper, using flow visualizations as well as pressure and friction plots
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
A Tool to Support Automation of Risk Assessment
No full textIn the context of risk analysis and assessment, the constant evolution and growth of organizations has led to an increase in the amount of information to be analyzed: a case is provided by the data processing registry, mandatory according to the GDPR. Quality and cost of risk analysis and assessment may be improved by using tools to automate certain steps. In this paper we propose an approach and a support tool for software-aided risk assessment integrated with the state-of-the-art privacy impact assessment (PIA) tool, to define how certain steps in the compilation of a DPIA (Data Protection Impact Assessment) can be automated. The resulting tool chain has been successfully applied to a case dealing with job placement data in a university
Regiospecific alkenylation of phenols by 1,1-dimethylallene promoted by platinum catalysts
No full text1,1-Dimethylallene reacts with phenolic substrates in the presence of catalytic amounts of platinum(II) complexes. A regiospecific C-alkenylation takes place, affording o-isopentenylphenols and 2,2-dimethylchromans. Possible reaction mechanisms are also 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
- …
