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作者:Schweinberger, Michael; Fritz, Cornelius
作者单位:Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park
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作者:Bertanha, Marinho; Chung, Eunyi
作者单位:University of Notre Dame; University of Illinois System; University of Illinois Urbana-Champaign
摘要:Classical two-sample permutation tests for equality of distributions have exact size in finite samples, but they fail to control size for testing equality of parameters that summarize each distribution. This article proposes permutation tests for equality of parameters that are estimated at root-n or slower rates. Our general framework applies to both parametric and nonparametric models, with two samples or one sample split into two subsamples. Our tests have correct size asymptotically while ...
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作者:Jin, Jiashun; Ke, Zheng Tracy; Luo, Shengming; Wang, Minzhe
作者单位:Carnegie Mellon University; Harvard University
摘要:In network analysis, how to estimate the number of communities K is a fundamental problem. We consider a broad setting where we allow severe degree heterogeneity and a wide range of sparsity levels, and propose Stepwise Goodness of Fit (StGoF) as a new approach. This is a stepwise algorithm, where for m = 1, 2, ..., we alternately use a community detection step and a goodness of fit (GoF) step. We adapt SCORE Jin for community detection, and propose a new GoF metric. We show that at step m, th...
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作者:Scealy, Janice L.; Wood, Andrew T. A.
作者单位:Australian National University
摘要:Compositional data are challenging to analyse due to the non-negativity and sum-to-one constraints on the sample space. With real data, it is often the case that many of the compositional components are highly right-skewed, with large numbers of zeros. Major limitations of currently available models for compositional data include one or more of the following: insufficient flexibility in terms of distributional shape; difficulty in accommodating zeros in the data in estimation; and lack of comp...
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作者:Vazquez-Bare, Gonzalo
作者单位:University of California System; University of California Santa Barbara
摘要:I set up a potential outcomes framework to analyze spillover effects using instrumental variables. I characterize the population compliance types in a setting in which spillovers can occur on both treatment take-up and outcomes, and provide conditions for identification of the marginal distribution of compliance types. I show that intention-to-treat (ITT) parameters aggregate multiple direct and spillover effects for different compliance types, and hence do not have a clear link to causally in...
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作者:Zhu, Yichen; Li, Cheng; Dunson, David B.
作者单位:Duke University; National University of Singapore; Duke University
摘要:Classification algorithms face difficulties when one or more classes have limited training data. We are particularly interested in classification trees, due to their interpretability and flexibility. When data are limited in one or more of the classes, the estimated decision boundaries are often irregularly shaped due to the limited sample size, leading to poor generalization error. We propose a novel approach that penalizes the Surface-to-Volume Ratio (SVR) of the decision set, obtaining a ne...
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作者:Anceschi, Niccolo; Fasano, Augusto; Durante, Daniele; Zanella, Giacomo
作者单位:Bocconi University; Bocconi University
摘要:A broad class of models that routinely appear in several fields can be expressed as partially or fully discretized Gaussian linear regressions. Besides including classical Gaussian response settings, this class also encompasses probit, multinomial probit and tobit regression, among others, thereby yielding one of the most widely-implemented families of models in routine applications. The relevance of such representations has stimulated decades of research in the Bayesian field, mostly motivate...
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作者:Mohammadi, Reza; Massam, Helene; Letac, Gerard
作者单位:University of Amsterdam; York University - Canada; Universite de Toulouse; Universite Toulouse III - Paul Sabatier
摘要:Bayesian structure learning in Gaussian graphical models is often done by search algorithms over the graph space.The conjugate prior for the precision matrix satisfying graphical constraints is the well-known G-Wishart.With this prior, the transition probabilities in the search algorithms necessitate evaluating the ratios of the prior normalizing constants of G-Wishart.In moderate to high-dimensions, this ratio is often approximated by using sampling-based methods as computationally expensive ...
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作者:Tuo, Rui; He, Shiyuan; Pourhabib, Arash; Ding, Yu; Huang, Jianhua Z.
作者单位:Texas A&M University System; Texas A&M University College Station; Renmin University of China; Oklahoma State University System; Oklahoma State University - Stillwater; Texas A&M University System; Texas A&M University College Station; Texas A&M University System; Texas A&M University College Station
摘要:This article develops a frequentist solution to the functional calibration problem, where the value of a calibration parameter in a computer model is allowed to vary with the value of control variables in the physical system. The need of functional calibration is motivated by engineering applications where using a constant calibration parameter results in a significant mismatch between outputs from the computer model and the physical experiment. Reproducing kernel Hilbert spaces (RKHS) are use...
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作者:Denti, Francesco; Camerlenghi, Federico; Guindani, Michele; Mira, Antonietta
作者单位:University of California System; University of California Irvine; University of Milano-Bicocca; Universita della Svizzera Italiana; University of Insubria; University of Milano-Bicocca; Collegio Carlo Alberto; Bocconi University
摘要:The use of large datasets for targeted therapeutic interventions requires new ways to characterize the heterogeneity observed across subgroups of a specific population. In particular, models for partially exchangeable data are needed for inference on nested datasets, where the observations are assumed to be organized in different units and some sharing of information is required to learn distinctive features of the units. In this manuscript, we propose a nested common atoms model (CAM) that is...