1,720,979 research outputs found
A divide and conquer approach for large spatial dataset
Get PDFIn recent times, the rise of `big data' has brought along major computational challenges in all the main disciplines of scientific research, including the field of spatial statistics. Some of these challenges include parametric estimation and quantification of estimation uncertainty that, when building statistical models using big data, pose an important computational load. Many methods have been proposed to address these challenges such as dimension reduction, approximation by Markov random fields, tapering of the covariance matrix, and subsampling based approaches. In this thesis a new \textit{divide-and-conquer} approach is proposed that we call \texttt{farmer} for providing effect size and standard error estimates in spatial models of big data. According to the proposed approach, all observations are divided into blocks that are mutually exclusive according to their position. For each block, the model parameters are estimated and recombined using a fixed or random meta-model to take into account the (possible) spatial dependence. This generalized method can be applied to a wide range of spatial models. For example, consider a linear Gaussian spatial model. In a simulation study, the \texttt{farmer} estimators were compared with estimators based on methods with similar sampling ideas. In the context of the Gaussian model, two applications with real data are presented. The proposed method appears computationally efficient compared to equivalent methods and has lower bias in the estimates. Furthermore, the proposed approach provides a more realistic estimate of standard errors. Finally, we propose an application of the method to generalized linear spatial models for simulated and real counting data
Impact of maternal and neonatal health initiatives on inequity in maternal health care utilization in Bangladesh
Get PDFBackgroundDespite remarkable progress in maternal and child health, inequity persists in maternal care utilization in Bangladesh. Government of Bangladesh (GOB) with technical assistance from United Nation Population Fund (UNFPA), United Nation Children’s Fund (UNICEF) and World Health Organization (WHO) started implementing Maternal and Neonatal Health Initiatives in selected districts of Bangladesh (MNHIB) in 2007 with an aim to reduce inequity in healthcare utilization. This study examines the effect of MNHIB on inequity in maternal care utilization.MethodTwo surveys were carried out in four districts in Bangladesh- baseline in 2008 and end-line in 2013. The baseline survey collected data from 13,206 women giving birth in the preceding year and in end-line 7,177 women were interviewed. Inequity in maternal healthcare utilization was calculated pre and post-MNHIB using rich-to-poor ratio and concentration index.ResultsMean age of respondents were 23.9 and 24.6 years in 2008 and 2013 respectively. Utilization of pregnancy-related care increased for all socioeconomic strata between these two surveys. The concentration indices (CI) for various maternal health service utilization in 2013 were found to be lower than the indices in 2008. However, in comparison to contemporary BDHS data in nearby districts, MNHIB was successful in reducing inequity in receiving ANC from a trained provider (CI: 0.337 and 0.272), institutional delivery (CI: 0.435 in 2008 to 0.362 in 2013), and delivery by skilled personnel (CI: 0.396 and 0.370).ConclusionsOverall use of maternal health care services increased in post-MNHIB year compared to pre-MNHIB year and inequity in maternal service utilization declined for three indicators out of six considered in the paper. The reductions in CI values for select maternal care indicators imply that the program has been successful not only in improving utilization of maternal health services but also in lowering inequality of service utilization across socioeconomic groups. Maternal health programs, if properly designed and implemented, can improve access, partially overcoming the negative effects of socioeconomic disparities
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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