1,720,957 research outputs found
Comparison of the ERA5 Wave Forecasting Dataset against Buoy Record
Full text linkAppropriate design of marine structures, such as offshore facilities and harbours, requires a detailed estimation of synthetic wave parameters. Inaccuracies and unreliability of wave data have implications in many aspects of marine engineering, such as structural strength, cost, and design. In this paper, a critical analysis of the most common data acquisition methods is made, focusing on in-situ instrumentation and numerical models. Considering the Pantelleria island as case study, records of a proprietary wave buoy and the ERA5 dataset of ECMWF (European Centre for Medium-Range Weather Forecasts) have been compared. This paper first highlights the methods and challenges of offshore experimental campaigns for wave monitoring and eventually presents a critical and quantitative comparison of the two approaches (experimental versus numerical), highlighting their respective advantages and disadvantages
FEM-aided structural design of a natural fiber composite made skiff
No full textIn racing boat design, the research is moved to find always the best compromise between performance and safety. The present work focuses on the description of the structural design cycle used by Polito Sailing Team during the realization of its new skiff, a high-performance sailing dinghy, built mainly with natural composite material such as balsa wood and flax fiber. The whole boat was completely designed by students, according to eco-sustainable principles, to participate in a universities competition called 1001VelaCup. To determinate the sandwich composite stratification, a benchmarking of materials was made by mechanical tests run according to ASTM 3039 and 3518 regulations. A finite element (FE) model was built to evaluate the static response of the structure, aiming to obtain a safe and light hull. The fluid (sea) interaction is modeled with a linear springs system. The crew, rig and rigging loads are obtained from a one-dimensional model and hydrodynamics pressure from ISO 12215-5:2014. The outputs obtained are consistent with the physics of the problem and the stresses distribution shows that the maximum stress is in the proximity of the mast base. This work constitutes the first step to obtain a correct, reliable and innovative design tool
Experimental validation of a FEM-aided structural design of an eco-sustainable high performance made skiff
Full text linkIn the racing boat design world, the most important aim is researching the best compromise between performances and safety. Nowadays, countless structural design tools exist, such as Finite Element Analysis (FEA), however every numerical model needs a controllable, repeatable, reliable experimental validation. The present work focuses on the structural design cycle adopted by Polito Sailing Team during the design and building of their own new skiff, a high-performance sailing dinghy, built mainly with natural composite material like balsa wood and flax fiber. The whole boat was completely designed by students, according to eco-sustainable principles, in order to participate in a university competition called 1001VelaCup
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
Wave energy converter mooring system: Available solvers and model validation
Full text linkTalking about mooring systems for Wave Energy Converter shall be taken into account not only the station-keeping problem but also the influence of the mooring on the device motion. In literature several software for mooring modeling could be investigated, and among these software MoorDyn should be considered for its versatility. By the way, each model should be validated against experimental data to test its reliability hence, the aim of these paper is to follow the analysis which starts from an overview of the mooring system models and software and which ends with a model validation which has been performed against the experimental data obtained during Naples experimental campaign. Device kinematic has been recorded through a data acquisition system equipped in the scaled wave energy converter, and it has been used as input of the numerical simulation. The force recorded with a load cells system, connected with the mooring lines and the device, has been compared with the numerical one, derived from MoorDyn, and they have shown a marked overlapping that witnesses the validation
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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