1,720,954 research outputs found
Carrier Frequency Offset Estimation in MIMO-OFDM Systems
Get PDFOrthogonal frequency division multiplexing (OFDM) is a popular method for high data rate wireless transmission. The performance of OFDM system is very sensitive to carrier frequency Offset (CFO), which introduces inter-carrier interference(ICI). Multi-input multi-output system used for increasing diversity gain and capacity of the system. Alamouti space time block code is used for MIMO transmission scheme. The basic method is used for Carrier Frequency Offset Estimation in OFDM system. In cyclic prefix (CP) based estimation, the CFO can be found from the phase angle of the product of the CP and corresponding rear part of the OFDM symbol. In CFO estimation using a training symbol, the CFO estimation range can be increased by reducing the distance between two blocks of samples for correlation. This was made possible by using training symbol that is repetitive with shorter period. An analytic expression in the form of mean square error (MSE) of frequency offset synchronization is reported, and simulation results verify theoretical analysis. Block-by-block CFO estimation is used in MIMO-OFDM system. In this algorithm we use block delay with other block and compare with the delay block. Analysis of the optimal size of block and minimization of the MSE of frequency estimator. We use S observation symbols they are grouped into two consecutive blocks with length A and S-A. The observation symbol, in each block is added sequentially and summed results are correlated block-wise
Mass and Volume Modeling of Strawberry Fruits (Arbutus unedo L) Based on Engineering Properties and Image Processing Approach
No full textStrawberry fruits are often graded based on size, shape, and colour, but it could be more efficient to grade them using mass or volume. Therefore, the relationships between the physical characteristics of fruit and its mass or volume are needed. Present study aims to predict the mass and volume of strawberry fruit based on measured values of selected physical parameters, and develop single and multivariate regression models like linear, quadratic, power, and exponential for prediction. Further, the mass and volume models were presented under different categories such as based on dimensions (including length, width, perimeter, and projected area), volumes, and density values. Among these models, quadratic was found appropriate. The experimental data analysis showed that the R2 of the quadratic model for the mass and the length, width, perimeter, and projected area were 0.893, 0.864, 0.908, and 0.909, respectively. In contrast, for the volume, R2 values were 0.887, 0.872, 0.905, and 0.910 for length, width, perimeter, and projected area, respectively. The results revealed that mass and volume modeling based on the projected area were the best-fit models with better prediction accuracy. The highest coefficient of determination (R2) was obtained for mass modeling of strawberries based on measured volume as R2 = 0.975. Mass modeling was recommended as the most accurate, reliable, and appropriate modeling compared to volume modeling. The findings of these study can be used as hyperparameters in automated grading system based on volume or weight of the individual fruit
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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