1,720,966 research outputs found
Influence of Design Parameters of Linear Oscillating Synchronous Excited Electrical Motor to Motor Indicators.
No full textFrequently the traditional rotating electrical machines are used to drive various linear oscillating mechanisms. The well developed design and gear mechanisms, good energy factors and well developed control system has influenced the wade popularity and usage of such rotating machines in industry and home appliance. But the usage of oscillating electrical motors is more effective for driving the linear oscillating mechanisms. The oscillating electrical machines are more frequently used in piston compressors, pumps of various fluids, saws, electrical valves and other mechanisms. This increase of use is caused by better power/mass ratio, gearless drive possibility, better total efficiency of the drive comparing with the traditional electrical machines. Nowadays the most investigated areas especially by foreign scientists are analysis and design of excited oscillating synchronous electrical machines with NdFeB magnet excitation system. The excited machines in comparison to non-excited ones has smaller dimensions, higher efficiency and power factor, but are more expensive due to the usage of magnets. It is relevant to investigate the influence of design parameters of linear oscillating synchronous excited electrical motor to motor indicators. There was an investigation based on variation of magnetic materials and analyzing the influence of the changes to motor indicators. In this final master thesis the linear oscillating synchronous excited electric motor was investigated. The outer magnetic core of the motor is \"C-core\" type with the single phase AC winding. For better design of the motor the magnets distributed by Halbach array were used in moving part of the motor. The modeling of the motors magnetic circuit was done by using the finite element method in two stages. In the first stage the magnetic material of the core an magnets were changed. In the second stage the air gap was varied. During the modeling the change of the motor parameters (indicators) was established
Rresearch of two-mass linear oscillating mechatronic device in spectral aspect.
No full textOscillating mechatronic devices are widely used for different purposes (in piston compressors, linear actuators, valve drives, artificial heart and other). The investigations are done in Lithuania and abroad. One of the main investigated problems is related to the research of the control systems of the displacement amplitude of oscillations with the indirect estimations of the displacement amplitude of oscillations. The indirect estimation is performed by using the spectrum information of the device. Also there are few investigations in the area of the diagnostics of the device. The aim of work – to investigate the work regimes, mover’s oscillation displacement amplitude estimation and control aspects, diagnostics aspects of two-mass oscillating mechatronic device by using oscillation displacement’s and current’s spectrum informative parameters. The doctoral dissertation work is dedicated to research and development of oscillating mechatronic devices analytical analysis, control system and diagnostics of the devices. The mathematical relationships between amplitudes of first harmonics’ of displacement of oscillations and total current and between the oscillation center shift and DC component of total current. The control algorithm with the indirect estimation of the displacement amplitude of oscillation was created considering the derived relationships. The composed mathematical model and structures of the device are presented. The sets of the faults and their indications were composed considering the total current information. During the experiment the parameters of the device were defined, the work characteristics were composed and the relationships between spectrum components’ amplitudes of displacement of oscillations and total current were confirmed. Also the relevance of the mathematical model was verified. The results of the work augment the research results of the devices and is suitable both for the non-excited and excited devices
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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