1,720,959 research outputs found
Approximate message passing algorithms for low complexity OFDM-IM detection
No full textLow complexity approximate message passing (AMP) orthogonal frequency division multiplexing combined with index modulation (OFDM-IM) detection algorithms are proposed, which exploit the sparse structure of the frequency domain (FD) OFDM-IM symbols. To circumvent the high root mean square error (RMSE) in the conventional AMP algorithm, a minimum mean square error (MMSE) denoiser is proposed based on the classic Bayesian approach and on the state evolution of AMP. Our simulation results demonstrate that it is capable of improving both the RMSE as well as the convergence rate. However, in practice, the channel's diagonal FD matrix may be a non-Gaussian sensing matrix, hence a damping strategy is conceived. In conclusion, the proposed MMSE denoiser based damping-assisted AMP-aided detector strikes a compelling bit error ratio vs. complexity trade-off
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
Performance Analysis and Approximate Message Passing Detection of Orthogonal Time Sequency Multiplexing Modulation
No full textIn orthogonal time sequency multiplexing (OTSM) modulation, the information
symbols are conveyed in the delay-sequency domain upon exploiting the inverse
Walsh Hadamard transform (IWHT). It has been shown that OTSM is capable of
attaining a bit error ratio (BER) similar to that of orthogonal time-frequency
space (OTFS) modulation at a lower complexity, since the saving of
multiplication operations in the IWHT. Hence we provide its BER performance
analysis and characterize its detection complexity. We commence by deriving its
generalized input-output relationship and its unconditional pairwise error
probability (UPEP). Then, its BER upper bound is derived in closed form under
both ideal and imperfect channel estimation conditions, which is shown to be
tight at moderate to high signal-to-noise ratios (SNRs). Moreover, a novel
approximate message passing (AMP) aided OTSM detection framework is proposed.
Specifically, to circumvent the high residual BER of the conventional AMP
detector, we proposed a vector AMP-based expectation-maximization (VAMP-EM)
detector for performing joint data detection and noise variance estimation. The
variance auto-tuning algorithm based on the EM algorithm is designed for the
VAMP-EM detector to further improve the convergence performance. The simulation
results illustrate that the VAMP-EM detector is capable of striking an
attractive BER vs. complexity trade-off than the state-of-the-art schemes as
well as providing a better convergence. Finally, we propose AMP and VAMP-EM
turbo receivers for low-density parity-check (LDPC)-coded OTSM systems. It is
demonstrated that our proposed VAMP-EM turbo receiver is capable of providing
both BER and convergence performance improvements over the conventional AMP
solution.Comment: Accepted in IEEE Transactions on Wireless Communication
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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