1,720,968 research outputs found
FPGA Realization of Hodgkin-Huxley Neuronal Model
No full textOne of the appealing cases of the neuromorphic research area is the implementation of biological neural networks. The current study offers Multiplierless Hodgkin-Huxley Model (MHHM). This modified model may reproduce various spiking behaviors, like the biological HH neurons, with high accuracy. The presented modified model, in comparison to the original HH model, due to its exact similarity to the original model, has more top performances in the case of FPGA saving and more achievable frequency (speed-up). In this approach, the proposed model has a 69 % saving in FPGA resources and also the maximum frequency of 85 MHz that is more than other similar works. In this modification, all spiking behaviors of the original model have been generated with low error calculations. To validate the MHHM neuron, this proposed model has been implemented on digital hardware FPGA. This approach demonstrates that the original HH model and the proposed model have high similarity in terms of higher performance and digital hardware cost reduction
A miniaturized microstrip Wilkinson power divider with harmonics suppression using radial/rectangular-shaped resonators
No full textIn this paper, a new power divider (PD) is designed initially; then a new PD has been proposed by replacing the conventional transmission lines with rectangular-shaped and radial-shaped resonators. It results in the extra harmonics suppression with a miniaturized circuit size. The proposed PD has been analyzed using even-mode/odd-mode analysis. The designed PD shows a very good fractional bandwidth. In addition, the proposed PD is miniaturized 41% approximately. Also, seven harmonics are eliminated. Finally, PD was implemented and the experimental results illustrate a good agreement with simulation results
Miniaturized microstrip suppressing lowpass cell for hybrid applications
No full textIn this paper, a very small microstrip low-pass filter (LPF) has presented for utilization in microwave systems. This device is composed of mirrored stepped impedances with two boxes at each side. A transfer function has been extracted from the relevant LC circuit, which expresses the function of this design. The operating frequency of the LPF is located at 3.5 GHz. The proposed LPF blocks a wide rejection with a rejection level of -20 dB or stronger. The return loss of 33 dB is another competence of the LPF. The overall size of the fabricated prototype is 9.5 mm x 5.8 mm (56 mm(2)). These dimensions maybe give the most compact lowpass filter operating in such frequency among the published work until now. The measurement results mimic the simulations
Miniaturized microstrip lowpass filter using cylindrical-shaped resonators for integrated applications
No full textA novel compact microstrip lowpass filter is presented in this paper. The structure uses stepped impedance and radial patches and it has the - 3 dB cut-off frequency at 4.39 GHz. The proposed lowpass filter has a wide rejection band from 6 to 30 GHz with rejection level more than - 20 dB. It has also other advantages such as: low insertion-loss < 0.1 dB and high return-loss more than 22 dB in 80% of the passband. The circuit size of the presented filter is about 90 mm(2). Such important advantages make the proposed lowpass filter applicable to be integrated in many high frequency circuits such as power amplifiers, oscillators, couplers and power dividers. It also can block the unwanted video transmitter interference nearby 4 GHz such as implementing between transmitter and antenna. The lowpass filter has simulated and fabricated and a good agreement was seen between the simulation and fabrication results
Miniaturized Wilkinson power divider with suppressed harmonics
No full textA Wilkinson power divider (WPD) with good novelty has been presented in this letter. To achieve this design, each quarter-wavelength lines of the conventional WPD have been replaced by two symmetrical comb-shaped resonators. These resonators create two rejection bands near their passbands, which can guarantee a good harmonics suppression for a power divider. By applying and computing the even-/odd-modes analysis, the suggested PD has been analyzed. In the proposed PD, the extra harmonics from second to 10th are suppressed. The normalized circuit size for operation in the center frequency of 1.1 GHz is about 0.06 x 0.07 lambda g. Eventually, fabrication of the power divider has been done on Rogers type RT-Duroid 5880 substrate and tested. The measured return loss is about 16 dB in the fundamental frequency. The obtained experimental S-parameters validated the primal design results. Therefore, the proposed WPD is a high performance one, which can be applied for applications such as the signal splitter in a Doherty power amplifier
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
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