1,721,072 research outputs found
Achievable rate analysis of the generalized spatial modulation uplink in multi-cell multi-user systems in the face of pilot contamination
No full textThe sum-rate of the multi-cell multi-user generalized spatial modulation (GSM) uplink is analyzed in the presence of realistic pilot contamination. A practical channel model associated with arbitrary transmit and receive correlation matrices is assumed for each user and base station (BS). Imperfect channel estimation is assumed with pilot contamination. The performance of a single-cell based minimum mean squared error (SMMSE) combiner is analyzed and compared to the ubiquitous zero forcing (ZF) combiner as well as matched filtering (MF). The transmit antenna (TA) index detection and the classicamplitude/phase modulation (APM) signal detection process are carried out separately for the sake of low complexity. Moreover, an algorithm based on order statistics is proposed for calculating the antenna detection probability conditioned on the actual TA. Finally, an approximation of the sum-rate is derived by exploiting the characteristics of massive MIMOs. Simulation results show that SMMSE has the best performance, followed by ZF and MF. Furthermore, the relationships between the system’s achievable rate and three systems parameters, namely the number of BS antennas, the signal-to-noise-ratio (SNR) and the interference factor of pilot contamination, are presented. The performance of different number of activated antennas are also compared.<br/
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
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
Terahertz measurements of hot hydronium ions (H3O+)with an extended negative glow discharge
Full text linkTerahertz absorption spectroscopy was employed to detect the ground-state inversion transitions of the hydronium ion. The highly excited ions were created with an extended negative glow discharge through a gas mixture of 1 mtorr of HO, 2 mtorr of H, and 12 mtorr of Ar, which allowed observation of transitions with and up to 12. In total forty seven transitions were measured in the 0.9--2.0 THz region and twenty two of them were observed for the first time. The experimental uncertainties range from 100 to 300~kHz, which are much better than those of 0.3--1.2~MHz reported in previous work. Differences up to 25.6~MHz were found between the observed positions and the catalog values that have been used for Herschel data analysis of observations towards Sagittarius B2(N), NGC 4418 and Arp 220.\footnote{Lis et al., \lq\lq Hot, metastable hydronium ion in the Galactic center: formation pumping in X-ray-irradiated gas?\rq\rq, {\em Phil.\ Trans.\ R.\ Soc.\ A}~{\bf 370}, 5162 (2012).}\footnote{Gonz\'alez-Alfonso et al., \lq\lq Excited OH, HO and HO in NGC 4418 and Arp 220\rq\rq, {\em Astrophys.\ Astronom} {\bf 550}, A25 (2013).} The new and improved measurements were fit to experimental accuracies with an updated Hamiltonian; and better HO predictions are reported to support the proper analysis of astronomical observations by high-resolution spectroscopy telescopes, such as Herschel,\footnote{Lis et al., \lq\lq Widespread rotaional-hot hydronium in the Galactic Interstellar Medium\rq\rq, {\em Astrophys.\ J.}, submitted (2014).} SOFIA, and ALMA.Made available in DSpace on 2014-09-17T16:56:25Z (GMT). No. of bitstreams: 3
license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5)
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abstract.txt: 1819 bytes, checksum: c4fbc1f8a3570255af510528fb96b57e (MD5)
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Previous issue date: 2014-06-1
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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