1,721,071 research outputs found
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
70-90-GHz self-tuned polyphase filter for wideband I/Q LO generation in a 55-nm BiCMOS transmitter
No full textA low-power quadrature local oscillator (LO) generation scheme embedded in a direct-conversion E-band transmitter (TX) is presented. A single-stage polyphase filter is closed in a loop and continuously tuned by means of a quadrature phase detector to maintain precise I/Q signals independently from LO frequency and component variations, thus making the solution wideband and robust against process, supply, and temperature variations. The analog phase detector, realized with fully balanced analog multipliers, is critical to reach high accuracy. Careful circuit analysis and simple design solutions are proposed to avoid systematic phase errors and to maintain high detector gain despite the high operating frequency. The TX, realized in BiCMOS 55-nm technology, delivers a maximum linear output power of 20.5 dBm at 80 GHz with 14% power efficiency. The LO buffers consumes 115 mW from 2.3-V supply while the LO calibration circuits need 16 mW only and allows to maintain a remarkable image rejection ratio of 40 dB or better over 70-90 GHz
Electronic properties and surface potential evaluations at the protein nano-biofilm/oxide interface: Impact on corrosion and biodegradation
Full text linkThe formation of a protein nano-biofilm, which exhibits a special electronic behavior, on the surface of metals or oxide biomaterials considerably influences the crucial subsequent interactions, particularly the corrosion and biodegradation processes. This study discusses the impact of electrical surface potential (ESP) of a single or nano-biofilm of albumin protein on the electrochemical interactions and electronic property evolutions (e.g., charge carriers, space charge capacitance (SCC), and band bending) occurring on the surface oxide of CoCrMo implants. Scanning Kelvin probe force microscopy (SKPFM) results indicated that ESP or surface charge distribution on a single or nano-biofilm of the albumin protein is lower than that of a CoCrMo complex oxide layer, which hinders the charge transfer at the protein/electrolyte interface. Using a complementary approach, which involved performing Mott-Schottky analysis at the electrolyte/protein/oxide interface, it was revealed that the albumin protein significantly increases the SCC magnitude and number of n-type charge carrier owing to increased band bending at the SCC/protein interface; this facilitated the acceleration of metal ion release and metal-protein complex formation. The nanoscale SKPFM and electrochemical analyses performed in this study provide a better understanding of the role of protein molecules in corrosion/biodegradation of metallic biomaterials at the protein nano-biofilm/oxide interface
Characterization of the native passive film on ferrite and austenite phases of sensitized 2205 duplex stainless steel
No full textHigh-Efficiency SiGe-BiCMOS E-Band Power Amplifiers Exploiting Current Clamping in the Common-Base Stage
No full textThis paper proposes high-efficiency E-band power amplifiers (PAs) in SiGe-BiCMOS based on a common-base output stage. A comparison between common-emitter and commonbase configurations proves the latter yields higher output power, enhanced linear range, and robustness against self-heating issues. Furthermore, the base-emitter junction of the BJT in common base can be exploited to implement the current-mode version of the well-known diode voltage clamper, so that the dc current tracks the signal current. This yields an improvement of efficiency, particularly in power back-off. Two PA designs are described: a single-path, two-stage amplifier and a second version delivering higher output power with transformer-based power combining at minimal efficiency degradation. At 80 GHz, the two PAs deliver 18- and 20.5-dBm OP1 dB and 19- and 21.5-dBm Psat. The PAE at OP1 dB is 22% and 20%; at 6-dB back-off, it is still 8.5% and 7.2%, respectively. The prototypes demonstrate two-three times higher PAE compared to previously reported silicon PAs with similar output power at the E-band
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