1,720,956 research outputs found
A deep learning based lightning location system
No full textThe paper presents a new approach for lightning location and peak current estimation based on Deep Learning (DL) algorithms. The basic idea is to use the time domain waveforms of the overvoltages induced by lightning strikes on transmission or distribution lines as features to regress both the location and the channel base current peak of a lightning event. Starting from previous research findings, the performance of the method have been further increased by proposing three different DL models, working either in the frequency or in the time domain. All models are trained with data simulated with the Lightning Power Electromagnetic Simulator for Transient Overvoltages (LIGHT-PESTO). The performances of the methods are first assessed on the same test case as the one presented in a previously published paper to show their increased effectiveness. Then, the best performing model among the three is tested on a more realistic network to show that, even in presence of much more complex systems, its performances are not reduced
A Novel Hybrid Boundary Element—Physics Informed Neural Network Method for Numerical Solutions in Electromagnetics
No full textIn this contribution the authors propose a hybrid Boundary Element Method - Physics Informed Neural Networks (BEM - PINN) approach, to be used for the resolution of partial differential equations arising when formulating boundary-value problems in electromagnetism. The approach retains both the advantages of integral methods (compact representation and no need to mesh large domains) and differential methods, where the term "differential"refers here to the Automatic Differentiation carried out during the training phase of the PINN. The method is easy to implement and adds an additional flexibility to purely PINN based solution methods
Preliminary Breakdown Pulses (PBP): A review on available data and models
No full textLightning is a major risk for humans, animals, and electrical systems. Many researches focused on the fully developed events, such as the Return Stroke (RS) current, the emitted electromagnetic fields, and the phenomenon modeling. However, there is poor understanding regarding precursors, such as Preliminary Breakdown Pulses (PBP). PBP are the pulses before the first RS. Studying these pulses provides understanding into the initial event that triggers the process within the cloud. Sufficient measurement data and a reliable model of PBP help to forecast the lightning flash development and help creating effective protection systems, ultimately enhancing the safety and reliability of electrical infrastructure and minimizing the risk of damage from lightinings. The aim of this paper is to conduct an extensive literature review to identify sources of measured data of PBP and the available modeling methods. The first part provides a review of key existing experimental studies, discussing aspects such as measurement equipment, signals, data, identification algorithms, and statistical observations. The second part discusses the methods available for modeling PBP categorized into descriptive and physical models. Descriptive models focus on reconstructing the primary PBP features from measured data, while physical models aim to explore the underlying physical mechanisms of PBPs
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
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
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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