1,721,267 research outputs found
Taxonomic Revision and Evolutionary Phylogeography of Dusky Langur (Trachypithecus obscurus) in Peninsular Malaysia
No full textDevelopment and study on transformer characteristics of a high repetition pulse generator
No full textHigh repetition pulse/ high frequency generators are of great interest for scientific and technological applications, including high voltage devices. This paper addresses the design and development of a high repetition pulse generator using a PIC microcontroller (PIC 16F877A). The PIC microcontroller generates two PWM pulses to drive the IGBTs through the optocouplers, which can perform fast switching in high voltage devices with low switching losses. The voltage and current supplied by the optocouplers make it perfectly suitable for the driving operations of IGBTs. Experiments were carried out to test its efficiency, and the waveforms of high repetition pulse frequency were observed by oscilloscope. The results of its operation present that the system could be used in the frequency range 2kHz < f < 200kHz. The system was also simulated by a Matlab Simulink model, in which two types of transformer were introduced to predict its validity in real operation with high voltage devices. The simulated results of the designed pulse generator show that the ignition coil transformer is more suitable than other iron core transformers for a high voltage with high pulse frequency. The system could be easily integrated with other high voltage devices to produce high pulsed frequency high voltages
Atmospheric electric field data logger system
No full textWeather can be unpredictable as there are a lot of uncertainties in predicting thunderstorms. Most of our navigation systems, including those on air, land and water, as well as broadcasting systems, are directly affected by the weather on a daily basis. The inconsistent and unreliable nature of storms brings out the importance of research in atmospheric electric field data logging systems. This paper presents a study to develop a virtual instrument with the capability to analyse and store the magnitude (data) of atmospheric electric fields. The study was carried out using a LabVIEW virtual instrument and tested using data acquisition (DAQ) and a function generator. The developed virtual instrument consists of waveform chart, tabulated data, and histogram for real time observation. Moreover, it has feature to save and recall data for further analysis
Khoo Kay Kim, professor of Malaysian history : a biobibliometric study
Full text linkPresents an analysis of the publication productivity, authorship pattern, channels of communication, journal preference and language preference of Professor Dato' Khoo Kay Kim, Professor of Malaysian History in the University of Malaya, Kuala Lumpur. The results of this biobibliometric study indicate that he can be a role model for future Malaysian historians to emulate his various achievements especially in the field of history education
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
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