1,721,138 research outputs found
Reinforcement Learning Based Dual-Functional Massive MIMO Systems for Multi-Target Detection and Communications
No full textReinforcement learning (RL) based approaches in massive multiple input multiple output (mMIMO) arrays allow target detection in unknown environments. However, there are two main drawbacks hindering the practical application of these approaches: (i) poor detection performance for weak targets, and (ii) mismatch between high system overhead and single functionality. In light of this, we propose a dual-functional mMIMO (DF-mMIMO) system for multi-target detection with embedded communication in this work. First, we improve the RL based multi-target detection algorithm in both "action" and "reward" steps, by adding an omni-directional detection pulse in the action step and optimizing the reward mechanism in the reward step, so greatly improving the detection probability of weak targets in strong clutter. To achieve the dual modalities, communication information is embedded into the radar transmit waveform via complex beampattern modulation. In particular, we propose a low computational complexity two-step beamformer design method. First, the transmit waveform covariance matrix is designed via convex optimization, and then the beamforming weight matrix is determined according to closed-form formulas. Extensive simulation results demonstrate that the proposed DF-mMIMO system exhibits excellent target detection capability in a scenario where both strong and weak targets co-exist with downlink communications
An Optimal Frequency Control Method of Asynchronous Power Grid Considering Multi-HVDC Emergency Power Support
Get PDFEmergency DC power support has become an effective frequency stability control approach. For the asynchronous power grid with multi-HVDC links, this paper proposes an optimal control based on wide-area measurements (WAMS). The prominent advantage of this control is to improve the frequency stability of the disturbed grid while taking into account the influence on power flow, node voltage and other grid frequency fluctuations. In order to evaluate the post-disturbance frequency stability, a steady-state frequency prediction model based on WAMS data is first proposed, which can reflect the correspondence between post-disturbance steady-state frequency and the DC power support amount. In order to obtain the optimal control strategy, an optimization model is established to formulate the proposed control problem. The optimization objective of the model is to minimize the frequency deviation of interconnected power grids, and the constraints are to restore steady-state frequency to target value and ensure the security of line power flow and node voltage. The final control strategy is obtained by solving the optimization model. Simulations of the modified IEEE 50-generator system are performed to validate the accuracy of the proposed frequency prediction model and the effectiveness of the proposed frequency stability control
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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