1,720,957 research outputs found
A new strategy for the structural weight reduction of naval vessels consistent with the latest development in the applicable rules
No full textIn this Ph.D. thesis an automatic design procedure for concept and preliminary phases of hull structural design is described. It allows investigating the design of ship structures, consisting of a series of stiffened panels surrounded by primary members, assembled to form the hull girder. The optimal configuration of the structural lay-out and the best scantling of each structural component (i.e. platings, ordinary stiffeners and primary elements) is provided, accounting for interactions among all structural components as well as integration of primary, secondary and tertiary responses. The proposed method allows the minimization of the overall weight of hull blocks intended as the sum of stiffened panels’ weight (shell and stiffeners) plus that of the surrounding primary members. A dedicated application in VBA language (Visual Basic for Applications) has been developed in which scantling checks have been implemented by applying a few rules formulations after a comprehensive analysis of involved variables defining the state of the hull structural system. The proposed scantling design approach is very practical, it follows well-known hull structural design principles and it takes advantage of the nowadays widely available computation means to update the traditional sequence of the scantling checks in a more rational way and to select the optimal lay-out scantling solutions among truly feasible ones
A fatigue assessment procedure for drilling pipes of scientific vessels
No full textIn recent years, many disasters due to earthquakes and
tsunamis occurred in various countries, including Japan. Two
triple junctions exist below the Japanese archipelago and around
Japan, where three plates meet to form a complicated crustal
structure. To conduct research on the Tohoku earthquake, which
accompanied the tsunami that devastated northern Japan in
March 2011, Japan Agency for Marine-Earth Science and
Technology (JAMSTEC) constructed the scientific deep-sea
drilling vessel Chikyu. To understand the mechanism of the
earthquakes, a direct access to the fault zone is necessary.
During drilling operations, the drill pipes are stressed by
different forces and the occurrence of drill-string failures is high,
which causes significant loss of money and time. This study
focused on the definition of a practical fatigue assessment
procedure useful to avoid failures during drilling operations. In
this paper the proposed procedure is outlined, and the sensitivity
analysis carried out to highlight most influencing parameters is
presented
Performance characterization of high-strength steel and quenched and tempered steels and their joints for structural applications
No full textAlthough in the last decades the applicable regulations for the design of steel structures have been deeply improved accounting
for modern design approaches and technologies, in a few industrial fields, concepts and formulations derived from centuries-old
experience are even nowadays the governing rule. This very often limits the potential offered by the technological innovations in
high-performance material, such as quenched and tempered (QT) steels. After having verified in the scientific literature, in the
commercial one and in several open material databases that some main data necessary to the comprehensive characterization of
QT steel used in building large metal structures are lacking, an extensive experimental campaign was undertaken to achieve an
updated and specific fatigue strength characterization for certain types of materials. The aimis to overcome the strict requirements
of current regulations on the application of both parent QT materials and welded homogeneous and heterogeneous joints between
different steel strength. The experimental campaign allowed filling the knowledge gap as well as providing further understanding
whether the use of high-strength steel is effective in the improvement of performances of large steel structures, whose fabrication
procedures are typical of building sites rather than workshops. Their extensive application in current building practice is expected
to be highly beneficial in terms of weight and costs
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
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
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