1,720,980 research outputs found
Provide a New Basic Unit for Cascaded Multilevel Inverter by Reducing the Maximum Blocking Voltage and Switches
No full textMultilevel converters provide high power capability, associated with low output harmonics and low commutation losses. Disadvantages of these converters are their complexity, requiring a great quantity of power devices and passive components, and a rather complex control circuitry. This work researches a novel multilevel converter topology using bidirectional and unidirectional auxiliary switches.In this article, a novel basic unit is recommended for cascaded multilevel converters. This unit is comprised of series connection of two basic units. The final topology is obtained from n-unit series of recommended unit. Important advantages of this topology are reducing maximum blocking voltage and Switches. Three different algorithms have been recommended to measure values of dc voltage sources and create symmetric and asymmetric modes. In this article, in addition to compare the recommended structure with conventional topologies, the ability of the recommended structure in generating all voltage levels is verified by simulation results of a 13-level inverter
A New Structure with New Algorithms for Cascaded Multilevel Inverters by Reducing Number of IGBTs
No full textCascaded multilevel inverters are usually used in a medium-voltage output. Hence, this converter has been declared as a vital substitute in the average-voltage inverter. In this article a novel structure for cascaded multilevel inverters have been proposed. Also, five algorithms are suggested to determine the amount of resources which are used in the new structure. The suggested topology has a number of benefits, including reducing the quantity of IGBTs and switches and required fee and installation area. Another benefit of the suggested structure is lower variety of the values of dc voltage sources in comparison with conventional structures. In this paper, the ability of proposed topology to produce all voltage levels with the result of the simulation is given to a17-level inverter
A new topology of cascaded multilevel inverter with reduced number of driver circuits and IGBTs
No full textReducing the number of required devices has a great importance in multilevel inverters area. In view of this, a cascaded multilevel inverter structure is proffered which requires the least number of components; IGBT and driver circuits. Four separate methods (algorithms) are recommended to ascertain the values of used DC voltage resources. In this paper, comparing the recommended topology with conventional structures from different aspects is done and comparison results are discussed. Simulation results of a 13-level inverter are shown in order to validate generating all voltage levels
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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