1,720,983 research outputs found
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
Parametric simulation approach for performance analysis of the power electronics circuits
No full textParametric simulation studies of active and passive circuit components provide extremely useful and much more information in the process of performance determination of power electronics circuits. The performances of power electronics circuits, for example, in DC-DC power converters, vary depending on the critical values of the passive circuit elements such as inductors and capacitors. Before the experimental realization of the power converters, in general, the values of the circuit components and the switching control circuit variables can be changed within a certain scenario, and the behavior of the power electronics circuit can be determined by parametric simulation studies. In addition, the behavior of the power electronics circuits under the load changes can also be tested. Thus, the values of the circuit components that can be calculated by classical methods can be determined with the parametric simulation approach and their effects on the performance of the power electronics circuit can be monitored with numerical data and 2D/3D graphics. In this chapter, the case of parametric simulation studies and performance determinations of the basic power electronics topologies such as multipulse rectifier circuits, DC-DC power converter circuits, and multilevel inverter circuits are presented. Thus, important information is given on the process of determining the behavior of power electronics circuits concerning both the switching parameters and the values of passive circuit elements and load changes, and to obtain datasets with a parametric simulation approach. In addition, examples of the co-simulation studies with power electronics circuits are presented about finite element analysis and electromagnetic modeling of the electrical effects such as energy efficiency and temperature increases of inductors and transformers in power electronic circuit structures and mechanical effects such as power density in kW/kg. Finally, it is thought that the approach brought by this chapter and the parametric datasets it presents regarding the performance determination of power electronics circuits will provide useful data for parameter estimation studies with artificial intelligence techniques. © 2024 Elsevier Inc. All rights reserved
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
MODELING AND ANALYSIS OF INVERTER OUTPUT TRANSFORMERS
No full textKesintisiz güç kaynakları ile güneş ve rüzgâr enerjisi gibi yenilenebilir enerji
kaynakları eviricilerinde, DA baranın yüklerden izole edilmesi ve/veya DA
baranın şebeke gerilimi seviyesine getirilmesi gibi amaçlarla evirici
transformatörleri kullanılmaktadır. Evirici transformatörleri yapısal özellikleri
bakımından şebeke frekansında çalışan standart transformatörlerden giriş
empedansı ve anahtarlama hataları sebebiyle oluşabilecek doyma etkisine
önceden tedbir alınması gibi yönleriyle farklılık gösterirler. Bununla birlikte
evirici transformatör tasarımı hem güç elektroniği hem de transformatör
tasarım bilgilerini gerektiren karmaşık bir konu olup, transformatörün yüksek
frekans davranışlarının da tasarımda dikkate alınması gerekir.
Elektrik makinelerinin davranışlarının modellenebilmesini sağlayan ve sonlu
elemanlar yöntemi ile analize olanak veren yazılımlar kullanıldığında nüve akı
dağılımı, indüklenen gerilimler, nüve kayıpları, sargı indüktansları, sargı
kayıpları, sargılarda oluşan kuvvetler gibi önemli tasarım parametreleri çok
yüksek bir doğrulukla hesaplanabilmektedir. Böylece klasik tasarım yönteminin
bir dezavantajı olan çok sayıda prototip üretimine gerek kalmamakta, değişik
geometri ve nüve özelliklerindeki transformatörler hızlı bir şekilde analiz
edilebilmektedir.
Tasarım sürecinde, akı dağılımının tahmin edilmesi büyük ölçüde önem
taşıdığından, paket yazılımlar ile görsel hale getirilmesi tasarımcıya öncelikle
neleri inceleyeceği konusunda rehber olmaktadır. Akıların görselleştirilmesi,
manyetik devrenin değişik bölgelerindeki kaçak ve faydalı akı dağılımını ortaya
çıkarmakta, aynı zamanda nüvedeki manyetik doyum durumu hakkında da
bilgi vermektedir.
Bu çalışmada, klasik tasarımlı transformatör ile ayrık nüve tasarımlı
transformatörün modellemesi yapılarak girişine şebeke ile modüle edilmiş
sinüsoidal PWM uygulanmıştır. Hem klasik ve hem de ayrık nüveli modellerden
elde edilen sonuçlar karşılaştırılmıştır. Bununla birlikte eviriciler için ayrık
nüve geometrisi ile tasarlanan transformatör kullanıldığında, harmonikleri yok
etmek için ayrıca filtre indüktörlerinin kullanılmasına gerek kalmadığı
görülmüştür.Inverter output transformers are used in Uninterruptible Power Supplies and
renewable energy sources (such as solar and wind) with the aim of isolating DC
link from loads and/ or adjusting DC link at the level of network voltage.
Inverter transformers are different from standard transformers in terms of
structural properties, such as input impedance and prevention from saturation
which is caused by switching errors. Therefore design of an inverter
transformer is complicated topic, which needs the information about both
power electronics and design of transformer. Besides behaviors of an inverter
transformers at high frequency level must be kept in view in the design.
When software's are used, which enables modeling of electrical machines
behaviors and analyzing with finite elements methods, some important design
parameters, such as core flux distribution, induced voltages, core losses, coil
inductances, stranded losses, forces in coils, can be determined with high
precision. A disadvantage of conventional design methods so that does not
require a large number of the production of prototypes, transformers which
have different geometry and core features can be analyzed quickly.
Because prediction of flux distribution is important in design process,
visualization with package programs guides the designer which point will be
inspected. Visualization of flux exposes escape and useful flows at different
zones of magnetic circuits and at the same time it gives also information about
the situation of magnetic saturation at core.
In this study, modeling of classical transformers and discrete core transformers
was realized and modular sinusoidal PWM via network was applied to the input
of inverter transformer. Obtained results from both single core and split core
transformers were compared. Therefore it was also proven that when split core
transformers have been used, there was no need to use filter inductors in order
to remove harmonics
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
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