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作者：Deng, Ke; Li, Yang; Zhu, Weiping; Liu, Jun S.
作者单位：Tsinghua University; Harvard University; Australian Defense Force Academy; Australian Defense Force Academy; University of New South Wales Sydney
摘要：As a technique to investigate link-level loss rates of a computer network with low operational cost, loss tomography has received considerable attentions in recent years. A number of parameter estimation methods have been proposed for loss tomography of networks with a tree structure as well as a general topological structure. However, these methods suffer from either high computational cost or insufficient use of information in the data. In this paper, we provide both theoretical results and ...
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作者：Liu, Ying; Wang, Yuanjia; Feng, Yang; Wall, Melanie M.
作者单位：Columbia University; Columbia University
摘要：We propose a Multiple Imputation Random Lasso (MIRL) method to select important variables and to predict the outcome for an epidemiological study of Eating and Activity in Teens. In this study 80% of individuals have at least one variable missing. Therefore, using variable selection methods developed for complete data after listwise deletion substantially reduces prediction power. Recent work on prediction models in the presence of incomplete data cannot adequately account for large numbers of...
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作者：King, Ruth; McClintock, Brett T.; Kidney, Darren; Borchers, David
作者单位：University of Edinburgh; National Oceanic Atmospheric Admin (NOAA) - USA; University of St Andrews; University of St Andrews
摘要：Capture-recapture data are often collected when abundance estimation is of interest. In this manuscript we focus on abundance estimation of closed populations. In the presence of unobserved individual heterogeneity, specified on a continuous scale for the capture probabilities, the likelihood is not generally available in closed form, but expressible only as an analytically intractable integral. Model-fitting algorithms to estimate abundance most notably include a numerical approximation for t...
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作者：Poppick, Andrew; McInerney, David J.; Moyer, Elisabeth J.; Stein, Michael L.
作者单位：University of Chicago; University of Adelaide; University of Chicago
摘要：Future climate change impacts depend on temperatures not only through changes in their means but also through changes in their variability. General circulation models (GCMs) predict changes in both means and variability; however, GCM output should not be used directly as simulations for impacts assessments because GCMs do not fully reproduce present-day temperature distributions. This paper addresses an ensuing need for simulations of future temperatures that combine both the observational rec...
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作者：Wang, Le; Shaw, Pamela A.; Mathelier, Hansie M.; Kimmel, Stephen E.; French, Benjamin
作者单位：University of Pennsylvania; University of Pennsylvania
摘要：The availability of data from electronic health records facilitates the development and evaluation of risk-prediction models, but estimation of prediction accuracy could be limited by outcome misclassification, which can arise if events are not captured. We evaluate the robustness of prediction accuracy summaries, obtained from receiver operating characteristic curves and risk-reclassification methods, if events are not captured (i.e., false negatives). We derive estimators for sensitivity and...
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作者：Tan, Linda S. L.; Chan, Aik Hui; Zheng, Tian
作者单位：Columbia University; National University of Singapore; National University of Singapore
摘要：Measuring the impact of scientific articles is important for evaluating the research output of individual scientists, academic institutions and journals. While citations are raw data for constructing impact measures, there exist biases and potential issues if factors affecting citation patterns are not properly accounted for. In this work, we address the problem of field variation and introduce an article level metric useful for evaluating individual articles' visibility. This measure derives ...
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作者：Goel, Sharad; Rao, Justin M.; Shroff, Ravi
作者单位：Stanford University; Microsoft; New York University
摘要：Recent studies have examined racial disparities in stop-and-frisk, a widely employed but controversial policing tactic. The statistical evidence, however, has been limited and contradictory. We investigate by analyzing three million stops in New York City over five years, focusing on cases where officers suspected the stopped individual of criminal possession of a weapon (CPW). For each CPW stop, we estimate the ex ante probability that the detained suspect has a weapon. We find that in more t...
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作者：Bendich, Paul; Marron, J. S.; Miller, Ezra; Pieloch, Alex; Skwerer, Sean
作者单位：Duke University; University of North Carolina; University of North Carolina Chapel Hill; Yale University
摘要：New representations of tree-structured data objects, using ideas from topological data analysis, enable improved statistical analyses of a population of brain artery trees. A number of representations of each data tree arise from persistence diagrams that quantify branching and looping of vessels at multiple scales. Novel approaches to the statistical analysis, through various summaries of the persistence diagrams, lead to heightened correlations with covariates such as age and sex, relative t...
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作者：Kang, Hyunseung; Kreuels, Benno; May, Juergen; Small, Dylan S.
作者单位：University of Pennsylvania; University of Hamburg; University Medical Center Hamburg-Eppendorf; Leibniz Association; Bernhard Nocht Institut fur Tropenmedizin
摘要：Most previous studies of the causal relationship between malaria and stunting have been studies where potential confounders are controlled via regression-based methods, but these studies may have been biased by unobserved confounders. Instrumental variables (IV) regression offers a way to control for unmeasured confounders where, in our case, the sickle cell trait can be used as an instrument. However, for the instrument to be valid, it may still be important to account for measured confounder...
