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作者:Mcgonigle, E. T.; Cho, H.
作者单位:University of Southampton; University of Bristol
摘要:Modern time series data often exhibit complex dependence and structural changes that are not easily characterized by shifts in the mean or model parameters. We propose a nonparametric data segmentation methodology for multivariate time series. By considering joint characteristic functions between the time series and its lagged values, our proposed method is able to detect changepoints in the marginal distribution, but also those in possibly nonlinear serial dependence, all without the need to ...
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作者:Robbins, Michael W.; Burgette, Lane
作者单位:RAND Corporation; RAND Corporation
摘要:Resampling techniques have become increasingly popular for estimation of uncertainty. However, data are often fraught with missing values that are commonly imputed to facilitate analysis. This article addresses the issue of using resampling methods such as a jackknife or bootstrap in conjunction with imputations that have been sampled stochastically, in the vein of multiple imputation. We derive the theory needed to illustrate two key points regarding the use of resampling methods in lieu of t...
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作者:Banerjee, Bilol; Bhattacharya, Bhaswar B.; Ghosh, Anil K.
作者单位:Indian Statistical Institute; Indian Statistical Institute Kolkata; University of Pennsylvania
摘要:In this paper we introduce a new measure of conditional dependence between two random vectors $ {\boldsymbol{X}} $ and $ {\boldsymbol{Y}} $, given another random vector $ \boldsymbol{Z} $ using the ball divergence. Our measure characterizes conditional independence and does not require any moment assumptions. We propose an estimator of the measure using a kernel-averaging technique and derive its asymptotic distribution. Using this estimator, we construct a test for conditional independence ba...
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作者:Liao, Jonquil Z.; Cape, Joshua
作者单位:University of Wisconsin System; University of Wisconsin Madison; University of Wisconsin System; University of Wisconsin Madison
摘要:This paper considers the problem of testing for latent structure in large symmetric data matrices. The goal is to develop statistically principled methodology that is flexible in its applicability, computationally efficient and insensitive to extreme data variation, thereby overcoming limitations of existing approaches. To this end, we introduce and systematically study certain symmetric matrices, called Wilcoxon-Wigner random matrices, whose entries are normalized rank statistics derived from...
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作者:Lin, K. Z.; Lei, J.
作者单位:University of Washington; University of Washington Seattle; Carnegie Mellon University
摘要:We consider a time-ordered sequence of networks stemming from stochastic block models in which nodes gradually change their membership over time, and no network at any single time-point contains sufficient signal strength to recover its community structure. To estimate the time-varying community structure, we develop the kernel-debiased sum of squares method that performs spectral clustering after a debiased sum-of-squared aggregation of adjacency matrices. Our theory demonstrates, via a novel...
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作者:Lin, Zeqin; Liu, Yiming; Pan, Guangming; Yao, Chi; Zhou, Jia
作者单位:Nanyang Technological University; Jinan University; Anhui University; Hefei University of Technology
摘要:We consider the problem of identifying the pattern of latent variables in high-dimensional linear latent variable models, which can also be interpreted as determining the source of spiked singular values in the data matrix. Specifically, we test whether the latent variables are continuous or categorical, a distinction that is crucial for data interpretation, but challenging in the high-dimensional regime. To address this inference problem, we analyse the asymptotic behaviour of empirical measu...
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作者:Henzi, Alexander; Shen, Xinwei; Law, Michael; Buhlmann, Peter
作者单位:Swiss Federal Institutes of Technology Domain; ETH Zurich
摘要:In recent years, there has been growing interest in statistical methods that exhibit robust performance under distribution changes between training and test data. While most of the related research focuses on point predictions with the squared error loss, this article turns the focus towards probabilistic predictions, which aim to comprehensively quantify the uncertainty of an outcome variable given covariates. Within a causality-inspired framework, we investigate the invariance and robustness...
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作者:Wiens, Douglas P.
作者单位:University of Alberta
摘要:We revisit a result according to which certain functions of covariance matrices are maximized at scalar multiples of the identity matrix. In a statistical context in which such functions measure loss, this says that the least favourable form of dependence is in fact independence, so that a procedure optimal for independent and identically distributed data can be minimax. In particular, the ordinary least squares estimate of a correctly specified regression response is minimax among generalized...
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作者:Casa, A.; Ferrari, D.; Huang, Z.
作者单位:Free University of Bozen-Bolzano; Royal Melbourne Institute of Technology (RMIT)
摘要:Pairwise likelihood is an approximation of the full likelihood function that facilitates the analysis of high-dimensional covariance models. By combining marginal bivariate likelihoods, it effectively simplifies high-dimensional dependencies, making the estimation process more manageable. We introduce estimation of sparse high-dimensional covariance matrices by maximizing a truncated version of the pairwise likelihood function, obtained by including pairwise terms corresponding to nonzero cova...
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作者:Li, Wei; Duan, Rui; Li, Sai
作者单位:Renmin University of China; Renmin University of China; Harvard University; Tsinghua University
摘要:Learning causal relationships between pairs of complex traits from observational studies is of great interest in many scientific fields. However, most existing methods assume the absence of unmeasured confounding and restrict causal relationships between two traits to be unidirectional, assumptions that may be violated in real-world systems. In this paper, we address the problem of bivariate causal discovery in the presence of unmeasured confounding and potential feedback loops, leveraging pos...