1,720,956 research outputs found
Wireless Power Transfer for Underwater Vehicles
No full textWireless power transfer (WPT) through magnetic resonance coupling (MRC) offers a safe and simple solution for underwater (UV) vehicles without being affected by water conductivity. Due to its ease of control in WPT systems, the most suitable topology is Serial-Serial (SS). In this study, square transmitting and receiving coils with dimensions of 40 cm-40 cm were designed for 3.3 kW power transmission at 85 kHz. The design was studied in the air, pure water, and seawater environments. Three different cases were analyzed with ANSYS Maxwell 3D. The WPT system responded similarly in air and pure water environments. However, it was determined that the eddy current loss increased, the mutual inductance decreased, the coupling factor weakened, and the critical air gap decreased by about 0.2 cm in the seawater environment. The results showed that the WPT system's efficiency was similar for air and pure water but tolerably lower in the marine environment. Further, the health effects of the WPT design were examined through the ANSYS HFSS, in line with the IEEE standard and ICNIRP guidelines
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
Optimization of a stand-alone PV system feeding a 1kW value asynchronous motor by digital compensation way
No full textBu çalışmada, şebeke bağlantısız olarak çalışan, su pompası gibi endüktif karakterli yükleri besleyen bir PV sistemin reaktif güç kompanzasyonu kontrolü yapılarak sistemde performans optimizasyonu elde edilmeye yönelik bir çalışma yürütülmüştür. Endüktif karakterli olan elektrik motoru gibi yükler enerji kaynağından reaktif güç talebinde bulunurlar. Reaktif güç, işe dönüşmediği gibi, sistem donanımları üzerinde fazladan termal enerji açığa çıkarır. Reaktif güç kompanzasyonu ile güç katsayısı kontrolü gerçekleştirilerek reaktif gücün minimumda tutulması sağlanır. Kompanzasyon işlemi, elektrik sistemlerinde meydana gelen ve işe yaramayan reaktif gücün azaltılması işlemidir. Çalışmaya esas sistem, standart bir stand- alone PV sisteme elektriksel olarak ek ünitelerin (kondansatör grubu vb.) bağlanması ve geliştirilmesi ile oluşturulmuştur. Sistem optimizasyonu açısından, çalışmaya esas sistem bileşenlerinin en küçük yapı taşına kadar matematiksel modellemeleri gerçekleştirilmiştir. Bunun yanı sıra, MATLAB kodları ve Simulink dinamik modellemeleri üzerinden performans simülasyonları yapılmıştır. Ek olarak, deneysel düzenekten elde edilen gerçek zamanlı veriler ile benzetim esaslı performans verileri karşılaştırılmıştır. Çalışma sonucunda, reaktif güç azaltılarak, sistemdeki akım taşıma kapasitesi artırılmış, akım azaldığı için termal enerjide bir düşüş elde edilmiş, dolayısıyla genel bir performans optimizasyonu sağlanmıştır. Başka bir deyişle, sistemin aynı gücü ve enerjiyi daha düşük akımlarla elde etmesi sağlanmıştır. Sistemin üzerindeki akım, ısı gibi yüklerin azaltılmasının, sistem ömrünün uzatmasının, verimini artırmasının yanı sıra orta ve uzun vadede finansal açıdan da kazanç sağlayacağı açıktır.In this study, Reactive Power Compensation (RPC) of micro-scale stand-alone PV systems that feed inductive loads such as water pump is performed to achieve the system's overall performance optimization. Loads such as an electric motor with inductive character also demand Reactive power from the energy source. Reactive power is never converted into useful energy but release extra thermal energy on system hardware. RPC and power factor control are performed to keep reactive power at a minimum. In the study, the system's current-carrying capacity was increased, thermal energy was reduced, and as a result, general performance optimization was achieved by this compensation process. The primary operating system was created by connecting and developing additional units (Capacitor group, etc.) electrically to a standard stand-alone PV system. In overall system optimization, mathematical models of the designed system components up to the smallest building blocks have been realized. Besides, performance simulations have been made using the developed MATLAB codes and dynamic models in Simulink. Additionally, the system's real-time simulation-based performance data were compared with data obtained from the experimental setup. The flow over the system will reduce the loads such as heat, current, increase efficiency, and provide financial benefits in the medium and long term. In other words, the system can obtain the same power and energy value at lower currents
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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