1,720,959 research outputs found
Parametric Analysis and Voltage Generation Performance of a Multi-directional MDOF Piezoelastic Vibration Energy Harvester
No full textPiezoelectric vibration energy harvesting has been extensively investigated in recent years and the majority of results focus on using the cantilever beam model under base driven motion. The main focus of this paper is to perform a parametric analysis of multi degrees of freedom piezo-elastic energy harvester to optimize the capability curve exploiting crossing/veering between modes. The structure under test consists of a combination of slender beams with one or more orthogonal beam segments placed on it. The resulting combined structure exhibits bending vibration modes in orthogonal planes. The cross and veering phenomena are studied in deep, attempting to improve the resulting mechanical-electrical energy conversion of the combined structure. A numerical model of the system under investigation is developed considering also non-classical damping. A parametric analysis of the system’ s performance due to geometrical and electrical properties variations are investigated to design a broadband harvester. An experimental analysis is performed on a test rig specially built to investigate the crossing and veering phenomena effects on the resulting output voltage from the energy harvester. Numerically simulated and experimental data are compared to provide information for updating the model as well as to address the efficiency of the harvester in terms of voltage generation
Using experimental modal analysis principles to evaluate the dynamics of catheter transducer system in invasive-pressure measurements
No full textSimultaneous Passive Vibration Attenuation and Energy Harvesting on a Fan-Folded Piezometaelastic Structure
No full textSimultaneous passive vibration suppression and energy harvesting through piezoelectric materials have been raising growing interest in the general area of structural dynamics. In the vibration isolation context, metastructures composed of multiple unit cells have played a major role in the design of suitable structures for the generation of frequency bandgaps, capable of mitigating structural vibration signals in a given frequency range. Additionally, concurrent energy harvesting in a given megastructure is possible through adequate positioning of piezoelectric layers on strategic locations along the metastructure geometric configuration. This work presents numerically simulated and experimental results of a study carried out on a given metastructure composed of a host beam with multiple resonators attached to it. Each resonator is designed from the arrangement of multiple beams forming a fan-folded structure that will significantly affect both, the vibration suppression as well as the capability of harvesting energy. Numerically simulated results are obtained through finite element modeling and a lumped parameter modeling methodology. Experimental results are gathered on a test prototype to verify the numerical results. Interesting results are obtained from multiple configurations of the individual fan-folded resonators as well as the total number of resonators positioned on the host beam
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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