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Application of the exact statistical inference frequently leads to a non-standard probability distributions of the considered estimators or test statistics. The exact distributions of many estimators and test statistics can be specified by…

Computation · Statistics 2018-01-09 Viktor Witkovský

This paper considers the problem of robustly estimating the parameters of a heavy-tailed multivariate distribution when the covariance matrix is known to have the structure of a low-rank matrix plus a diagonal matrix as considered in factor…

Computation · Statistics 2019-09-30 Rui Zhou , Junyan Liu , Sandeep Kumar , Daniel P. Palomar

We revisit the classical problem of estimating an unknown distribution from its samples by fitting a mixture model that minimizes cross-entropy loss. Framing the task as a stochastic convex optimization problem over the space of $ M…

Machine Learning · Statistics 2026-05-26 Mohammadreza Ahmadypour , Tara Javidi , Farinaz Koushanfar

The Heckman selection model is one of the most well-renounced econometric models in the analysis of data with sample selection. This model is designed to rectify sample selection biases based on the assumption of bivariate normal error…

Methodology · Statistics 2025-11-26 Heeju Lim , Jose Alejandro Ordonez , Victor H. Lachos , Antonio Punzo

We introduce a novel class of Bayesian mixtures for normal linear regression models which incorporates a further Gaussian random component for the distribution of the predictor variables. The proposed cluster-weighted model aims to…

Methodology · Statistics 2026-05-26 Panagiotis Papastamoulis , Konstantinos Perrakis

Microbial communities analysis is drawing growing attention due to the rapid development of high-throughput sequencing techniques nowadays. The observed data has the following typical characteristics: it is high-dimensional, compositional…

Methodology · Statistics 2020-04-30 Yong He , Pengfei Liu , Xinsheng Zhang , Wang Zhou

We consider a semiparametric mixture of two univariate density functions where one of them is known while the weight and the other function are unknown. Such mixtures have a history of application to the problem of detecting differentially…

Statistics Theory · Mathematics 2017-08-01 Zhou Shen , Michael Levine , Zuofeng Shang

We propose a general approach to construct weighted likelihood estimating equations with the aim of obtain robust estimates. The weight, attached to each score contribution, is evaluated by comparing the statistical data depth at the model…

Methodology · Statistics 2018-02-16 Claudio Agostinelli

This PhD Thesis presents an investigation into the analysis of financial returns using mixture models, focusing on mixtures of generalized normal distributions (MGND) and their extensions. The study addresses several critical issues…

Statistical Finance · Quantitative Finance 2024-11-20 Pierdomenico Duttilo

For a sample of absolutely bounded i.i.d. random variables with a continuous density the cumulative distribution function of the sample variance is represented by a univariate integral over a Fourier series. If the density is a polynomial…

Statistics Theory · Mathematics 2008-10-10 T. Royen

Cluster-weighted modeling (CWM) is a mixture approach for modeling the joint probability of a response variable and a set of explanatory variables. The parameters are estimated by means of the expectation-maximization algorithm according to…

Computation · Statistics 2013-08-09 Salvatore Ingrassia , Simona C. Minotti

We consider a multitask estimation problem where nodes in a network are divided into several connected clusters, with each cluster performing a least-mean-squares estimation of a different random parameter vector. Inspired by the…

Systems and Control · Computer Science 2017-04-26 Yuan Wang , Wee Peng Tay , Wuhua Hu

We present a Bayesian mixture model for estimating the joint distribution of mixed ordinal, nominal, and continuous data conditional on a set of fixed variables. The model uses multivariate normal and categorical mixture kernels for the…

Methodology · Statistics 2016-07-14 Maria DeYoreo , Jerome P. Reiter

Graphical Gaussian models have proven to be useful tools for exploring network structures based on multivariate data. Applications to studies of gene expression have generated substantial interest in these models, and resulting recent…

Methodology · Statistics 2011-08-10 Michael Finegold , Mathias Drton

In this paper, we develop a simulation-based framework for regularized logistic regression, exploiting two novel results for scale mixtures of normals. By carefully choosing a hierarchical model for the likelihood by one type of mixture,…

Methodology · Statistics 2015-03-17 Robert B. Gramacy , Nicholas G. Polson

To avoid specification of the error distribution in a regression model, we propose a general nonparametric scale mixture model for the error distribution. For fitting such mixtures, the predictive recursion method is a simple and…

Methodology · Statistics 2015-09-03 Ryan Martin , Zhen Han

An important and yet difficult problem in fitting multivariate mixture models is determining the mixture complexity. We develop theory and a unified framework for finding the nonparametric maximum likelihood estimator of a multivariate…

Statistics Theory · Mathematics 2007-06-13 Ramani S. Pilla , Francesco Bartolucci , Bruce G. Lindsay

Non-parametric estimation of a multivariate density estimation is tackled via a method which combines traditional local smoothing with a form of global smoothing but without imposing a rigid structure. Simulation work delivers encouraging…

Methodology · Statistics 2016-10-10 Adelchi Azzalini

The theory of normal variance mixture distributions is used to provide elementary derivations of closed-form expressions for the definite integrals $\int_0^\infty x^{-2\nu}\cos(bx)\gamma(\nu,\alpha x^2)\,\mathrm{d}x$ (for $\nu>1/2$, $b>0$…

Probability · Mathematics 2024-05-29 Robert E. Gaunt

The normal-inverse-Wishart (NIW) distribution is commonly used as a prior distribution for the mean and covariance parameters of a multivariate normal distribution. The family of NIW distributions is also a minimal exponential family. In…

Statistics Theory · Mathematics 2024-06-04 Jonathan So