1,720,986 research outputs found
EVALUATING THE SEISMIC EFFECTS ON LIFTING EQUIPMENT
No full textThe purpose of this paper is to assess the dynamic behaviour of various lifting equipment
(different types of cranes, elevating work platform, etc.) subjected to seismic actions,
evaluating how these actions can both generate failures and affect the structural behaviour of
the machine. The work is developed starting from the design of the different machines of
interest (according to some classical standards and specific performance like working load,
lifting speed, working area, etc.), determining their geometry. Subsequently are applied the
characteristic load spectra to the structures, related to the magnitude of earthquake; the final
step consist in the structural analysis of the machines, computing their maximum stresses,
displacements and natural frequencies, using different finite element codes. The results show
that the first natural frequencies of the structures are very low and consequently the effects of
the seismic action, in general, are not dangerous. Otherwise it is important to underline that
the maximum stress induced by the earthquake is detectable in different position in the lifting
equipment respect to maximum stress position in the normal loading operations, therefore
seismic analyses are indispensable for study these parts of machines
Supplementary Material To 'An Experimental Approach For The Determination Of Axial And Flexural Wavenumbers In Circular Exponentially Tapered Bars' : First Release
No full textSupplementary material to 'An experimental approach for the determination of axial and flexural wavenumbers in circular exponentially tapered bars' by Michał K. Kalkowski, Jen M. Muggleton, Emiliano Rustighi, Journal of Sound and Vibration, Volume 390, 3 March 2017, Pages 67-85, ISSN 0022-460X, http://dx.doi.org/10.1016/j.jsv.2016.10.018</span
Supplementary material to 'An experimental approach for the determination of axial and flexural wavenumbers in circular exponentially tapered bars' : First release
No full text<p>Supplementary material to 'An experimental approach for the determination of axial and flexural wavenumbers in circular exponentially tapered bars' by Michał K. Kalkowski, Jen M. Muggleton, Emiliano Rustighi, Journal of Sound and Vibration, Volume 390, 3 March 2017, Pages 67-85, ISSN 0022-460X, http://dx.doi.org/10.1016/j.jsv.2016.10.018</p>
An experimental approach for the determination of axial and flexural wavenumbers in circular exponentially tapered bars.
No full textData and code (as Jupyter notebook) allowing for generating results presented in figures in Michał K. Kalkowski, Jen M. Muggleton, Emiliano Rustighi, An experimental approach for the determination of axial and flexural wavenumbers in circular exponentially tapered bars, Journal of Sound and Vibration, Volume 390, 3 March 2017, Pages 67-85, ISSN 0022-460X, http://dx.doi.org/10.1016/j.jsv.2016.10.018
Work was funded by EPSRC, Assessing the Underworld (EP/K021699/1) </span
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
Optimal and Quasi-Optimal Automatic Tuning of Vibration Neutralizers
No full textVibration neutralizers are single-degree-of-freedom devices affixed to vibrating structures in order to reduce the response at a specific troublesome harmonic excitation frequency. As this frequency may vary over time, it becomes imperative to track and adjust the neutralizer to maintain the optimal performance. Recent years have witnessed the emergence of adaptive tunable vibration neutralizers, offering real-time adjustment capabilities through external actions. Thanks to real-time control algorithms, these devices enable the automatic mitigation of vibration levels in mechanical structures. A particularly successful algorithm for the automatic tuning of these devices leverages the phase angle between the base acceleration and the neutralizer’s mass. This study critically examines the justification for employing such an algorithm and scrutinizes its optimal applicability limits, particularly in the context of viscous and structurally damped systems. The findings reveal that this algorithm accurately approximates optimum tuning for systems with low damping. Moreover, from an engineering perspective, the algorithm remains acceptable even for heavily damped structures. Through a focused and comprehensive analysis, this paper provides valuable insights into the efficacy and limitations of the phase-angle-based tuning algorithm, contributing to the advancement of adaptive vibration control strategies in smart structures
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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