1,720,959 research outputs found
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
Design and characterization of InP based Mach-Zehnder modulators at 2μm wavelength
Get PDFThe Mach-Zehnder modulators (MZMs) based on InP are the key building blocks of photonic integrated circuits (PICs) due to low drive voltage and higher electro-optic (EO) bandwidth. They are the most suitable candidates to replace the widely deployed large footprint Lithium Niobate (LiNbO3) based MZMs. This thesis is focused on the design and development of travelling wave InP MZMs operating in the conventional optical C-band and also at 2000 nm which is one of the newly proposed possible alternatives for optical transmission to avoid highly anticipated ‘Capacity Crunch‘in the currently deployed standard single mode fiber (SSMF) in the next decade. InP MZMs working around the 1550 nm wavelength range were developed and characterised under DC and high frequency in order to validate the optimal electrode design. The highlight of presented work is the development of the first InP MZMs for operation around 2000 nm wavelengths for used in future optical transmission systems. To make the operation feasible around 2000 nm wavelength, compressively strained InGaAs QWs are used in the optical waveguide. The developed modulators exhibit a 3-dB EO bandwidth of 9 GHz with switching voltage as low as 3.2 V for a 3 mm long electrode. It is also shown that maximizing the electro-optical overlap by increasing the number of quantum wells can significantly reduce the Vπ, hence the modulator driving conditions for higher order modulation formats, without sacrificing the modulation bandwidth and device dimensions. Further, the devices are packaged using specially designed RF interposer to be used in an efficient, high-capacity WDM transmitter for communication over 1.15 km hollow-core photonic bandgap fiber (HC-PBGF) at 2 μm wavelength. A WDM capacity of 40 Gb/s is accomplished by using four 10 Gb/s NRZ-OOK externally modulated channels for the first time and transmission performance is evaluated using a direct detection receiver
Tomographic and Morphometric Reconstruction and Analysis With Applications in Material Science and Neuroimaging
No full textComputed tomography is increasingly enabling scientists to study physical processes of materials at micron scales. The MBIR framework provides a powerful method for CT reconstruction by incorporating both a measurement model and prior model. Classically, the choice of prior has been limited to models enforcing local similarity in the image data. In some material science problems, however, much more may be known about the underlying physical process being imaged. In this work, we propose an MBIR framework with a physics based prior model - namely the Cahn-Hilliard equation. The Cahn-Hilliard equation can be used to describe the spatio-temporal evolution of binary alloys. After formulating the MBIR cost with the Cahn-Hilliard prior, we use the Plug-And-Play algorithm with ICD optimization to minimize the resulting cost. We first apply this method to simulated data using the interlaced-view sampling method of data acquisition. Results show superior reconstruction quality compared to the FBP and model-based iterative reconstruction with total variation prior. We next reconstruct a real Al-Cu alloy sample using our method, and compare the results to MBIR with a total variations prior. As a partially related problem, neuroimaging tools are finding increasing use in detecting and analyzing brain changes related with contact sports. About 1.6-3.8 million sports related injuries take place every year, according to an estimate. We investigate the gray matter volume and thickness changes, particularly in the brain regions susceptible to impact, in a population of high school football and soccer athletes. We also correlate functional connectivity changes in soccer athletes with the intensity and length of their sport experience
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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