1,720,966 research outputs found
Investigation of a Kelvin-Source Connected SMD Silicon MOSFET and its Application in a High Current Full Bridge Synchronous Rectifier
No full textAuxiliary loads in an electric vehicle (EV) are in the order of 12-48 V since voltages above 50 V pose risks to the passengers. Power demand on auxiliary loads continues to expand due to increased computation requirements and load profiles. This requires development of power conversion systems that can manage high-currents efficiently. Construction of high current power conversion systems require multiple power switches (MOSFETs) in parallel, which reduce conduction losses. Efficiency can be further improved by incorporating Kelvin-source connections due to improved decoupling of the gate-source (G-S) and drain-source (D-S) loops in a MOSFET. This paper proposes a method to create a Kelvin-source connection in SMD silicon (Si) MOSFET packages with multiple source terminals. A comparison of switching energies between the conventional and proposed methods to highlight the improvements is performed. A 10-14 V/2.8 kW capable full bridge (FB) synchronous rectifier is constructed for application in a DC-DC converter. Parallel connected HDSOP-16 Si MOSFET packages are used to construct this rectifier with the proposed Kelvin-source and imbalances of the root-mean-square (RMS) current (IRMS), turn-on (Ion) and turn-off (Ioff) currents, resultant power loss profile and effect on the design's thermal gradient are studied
Digital Closed Loop Control of a Three Port Series Resonant Converter for Electric Vehicles
No full textWith the trend towards vehicle electrification, three port DC-DC converters allow an interface between the high-voltage battery pack, a 12 V battery pack and the 48 V auxiliary loads within the electric vehicle compared to conventional two-port converters. Due to the dependence of auxiliary loads on driving behaviour and passenger input, a robust controller is essential for a three-port converter to handle dynamically changing load profiles on the loading ports. This paper presents a design procedure of a digital closed loop controller (DCLC) utilizing decoupling control for a three port series resonant converter (TPSRC). The DCLC is developed on a hardware demonstrator for the voltage mode control of the loading ports (ports 2 and 3). Delays introduced from the practical implementation of the DCLC are defined to formulate inner and outer loop frequency responses and assist in compensator design. Load stability analysis is considered to determine the admissible operating region of the designed compensators. A soft start strategy to limit inrush currents in the TPSRC is utilized. Experimental results demonstrating the DCLC under voltage reference and step load changes on the hardware demonstrator of a 6 kW TPSRC are presented
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
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