1,720,972 research outputs found
Development and test of a universal FPGA-based Arc Detector for accelerating cavities at the facility for Antiproton and Ion Research FAIR [10.08.2011]
No full textOnTEAM metadata: GDSID: DOC-2011-Nov-83; Attribute ID: LIBRARY-thesis_ma-2011-001; Title: [GSI Ma 2011-01] Development and test of a universal FPGA-based Arc Detector for accelerating cavities at the facility for Antiproton and Ion Research FAIR [10.08.2011]; Author(s): Omet, Mathieu; Corporate author(s): ; Publication date: 20111116; Creator: manton; Creation date: 16.11.2011 16:02:19; Change date: 16.11.2011 16:44:09; Access: Welt; Attribute type: Text.Thesis.MA; Directory path: ['GSI Publications', 'GSI as Publisher']; Attribute path: ['Infrastructure', 'Library and Documentation', 'thesis_ma', 'Added in 2011']; File name(s): ['DOC-2011-Nov-83-1.pdf']; File title(s): ['']; File access: ['GSI-intern'
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
Entwicklung, Aufbau und Test eines Hochfrequenz-Amplitudendetektors für den Recycled Experimental Storage Ring RESR bei der Facility for Antiproton and Ion Research FAIR (5.1.2009)
Full text linkVariations 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
Digital Low Level RF Control Techniques and Procedures Towards the International Linear Collider
No full textIn this work digital Low Level Radio Frequency (LLRF) control techniques and procedures developed and successfully tested in the scope of the International Linear Collider (ILC) are described.One central requirement for the operation of ILC is the high gradient near (5% below) quench limit operation during the whole flattop of multiple cavities driven by a single klystron. In order to achieve such an operation, for every cavity the driving power (Pk) and the loaded quality factor (QL) have to be controlled individually. Thus this operation mode is called PkQL operation. At the superconducting RF test facility (STF) at KEK in the scope of the Quantum Beam (QB) project two superconducting 9-cell cavities were driven by a single klystron. At this setup an automated procedure was developed and tested, resulting in the world's first actual and fully successful PkQL operation. A stable one hour long-time run with a beam of in average 6.4 mA current was achieved. The cavity gradients were 16 and 24 MV/m and with this 5% below the virtual quench limits of 16.8 and 25.2 MV/m. The achieved vector sum gradient and phase stabilities were Delta A/A = 0.009% and Delta phi = 0.009 deg., respectively. Furthermore in a simulation a successful automated PkQL setting procedure and PkQL operation for 39 cavities fulfilling all ILC requirements were demonstrated.Due to the PkQL operation a further requirement in scope of ILC is to operate the cavities at high loaded quality factors. In order to demonstrate the feasibility of such an operation, the loaded quality factors of both superconducting 9-cell cavities at KEK STF in the scope of the QB project were set to QL,cav1 = QL,cav2 = 2*10^7. Under this condition a stable one hour long-time operation with a beam of in average 6.1 mA current was conducted. Both cavity gradients were 20 MV/m. The achieved vector sum gradient and phase stabilities were Delta A/A = 0.011% and Delta phi = 0.015 deg., respectively.At ILC it is planned to operate the klystrons 7% in power below their full saturation. Due to the saturation behavior in amplitude the control gain converts to 0 at this region, which inhibits effective control. In order to keep the control gain constant up to the point of saturation and with this allowing effective control up to this point, predistortion-type FPGA-based klystron linearization algorithms were decided to be used. Four different kinds of algorithms have been developed, successfully tested, and compared. The best algorithm is based on lookup tables combined with a linear interpolation. In a simulation it was demonstrated that an extension of this algorithm with an adaptive grid spacing further improves the linearization performance.For offline tests of the klystron linearization algorithms an FPGA-based klystron and cavity simulator was developed, implemented, and tested
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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