1,720,979 research outputs found
Stratospheric Ballooning With SPIDER and BIT
No full textStratospheric ballooning is an important platform for astrophysics and cosmology. This work presents the development of Spider, a CMB polarimeter, and BIT, a visible light and near-UV imager, both of which are balloon experiments. Both experiments require gondolas and pointing systems to track or scan on the sky, and their development is an important area of research in the field.
Spider aims to observe the relics of inflation by constraining the tensor to scalar ratio, r. It flew an initial flight in 2014-15 and the data analysis is presented here. This work includes the development of the Spider noise model which is an important component of any CMB analysis. Development work on the second Spider gondola is also presented, preparing it for a second Antarctic campaign in the near future.
BIT is attempting to constrain Ω_m , the energy density of matter and σ_8 , the scale size of early universe fluctuations, through the use of weak lensing. Although no weak lensing data has been obtained yet, this thesis presents the development of the instrument from its earliest stages through its two successful test flights. Specific emphasis is given to the development of the star camera subsystem, which was integral to the success of the project.Ph.D.2020-07-21 00:00:0
Design and Optimization of a 1.5m Telescope Balloon Borne Gondola
Get PDFGigaBIT is the successor of the Balloon-Borne Imaging Testbed (SuperBIT), a 1.5m telescope that operates in the stratosphere. The GigaBIT gondola must support a telescope almost double the size of SuperBIT while still adhering to the mass restrictionset forth by its predecessor as it will be launched with the same balloon. This presents the challenge of designing a lightweight gondola, strong enough to survive the necessary structural safety requirements and rigid enough to allow for sub-arcsecond
pointing. This thesis explores the design process and development of the gondola. This was done using topological optimization to determine the optimal structural geometry of the gondola’s frames. From there, a design was produced, analyzed and
amended rigorously following static analysis results to adhere to the mandatory design specifications set forth by the Gondola Structural Design Requirements. This design represents a foundation for future balloon-borne astronomy.M.A.S
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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