1,720,958 research outputs found
Optimal parameters for experimental dynamic testing
No full textModal testing is normally performed by experienced test engineers and technicians. On the base of their expertise, they define the best set up for extracting all the requested information from a vibrating structure. They decide how to suspend it and where, how many sensor and which kind of exciters have to be used and where they have to be placed, they select the best acquisition parameters and so on. In most of the cases this sensibility leads to excellent results, still sometimes, once the measurements are done, the quantity and the quality of the acquired data is not sufficient for the tasks ahead. Several parameters have been defined in the previous years to help the experimenters defining the best set-up. Often the interpretation of these indexes is subjective and applicability is limited due to the test pieces’ geometry. This paper presents two new pre-test indicators focused on the optimal sensor and exciter positioning that reduce the personal intervention. These indexes provide a large spectrum of solutions, supplying more possibilities for the experimenter to acquire a complete and reliable database
Sine sweept excitation of MDOF systems
No full textSine sweep excitation is frequently used to excite large structure for the identification of modal
parameters. The advantage of the technique lays in the possibility of speeding up the test procedure when
compared with the stepped sine approach still keeping the possibility to identify non-linearities if the
sweep rate is kept low. Even if some indication of the allowable sweep rate are recommended in a
standard (ISO 7626) practically all the theoretical work has been done on SDOF systems. In this work, the
authors will present some considerations on sweep sine excitation applied to a MDOF (8dof) system with
an unbalanced mass providing the excitation. The idea behind such model is related to the will to
extrapolate the rigid body dynamics of complex machinery with rotating unbalanced shafts. The MDOF
system allows to make considerations of the influence of the coupling between the DOFs, and to
understand the influence of the sweep rate on the different natural frequencies
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
