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Related papers: Multivariate Geometric Skew-Normal Distribution

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Motivated by the need for parametric families of rich and yet tractable distributions in financial mathematics, both in pricing and risk management settings, but also considering wider statistical applications, we investigate a novel…

Statistical Finance · Quantitative Finance 2009-01-06 William T. Shaw , Ian R. C. Buckley

A method that uses order statistics to construct multivariate distributions with fixed marginals and which utilizes a representation of the Bernstein copula in terms of a finite mixture distribution is proposed. Expectation-maximization…

Computation · Statistics 2014-01-16 Xiaoling Dou , Satoshi Kuriki , Gwo Dong Lin , Donald Richards

Popular deterministic approximations of posterior distributions from, e.g. the Laplace method, variational Bayes and expectation-propagation, generally rely on symmetric approximating families, often taken to be Gaussian. This choice…

Methodology · Statistics 2026-01-19 Francesco Pozza , Daniele Durante , Botond Szabo

In this paper, we present an algorithm for the fitting of a location-scale variant of the canonical fundamental skew t (CFUST) distribution, a superclass of the restricted and unrestricted skew t-distributions. In recent years, a few…

Methodology · Statistics 2014-02-03 Sharon X. Lee , Geoffrey J. McLachlan

This paper provides a framework for estimating the mean and variance of a high-dimensional normal density. The main setting considered is a fixed number of vector following a high-dimensional normal distribution with unknown mean and…

Methodology · Statistics 2019-05-07 Shyamalendu Sinha , Jeffrey D. Hart

We provide a general theory of the expectation-maximization (EM) algorithm for inferring high dimensional latent variable models. In particular, we make two contributions: (i) For parameter estimation, we propose a novel high dimensional EM…

Machine Learning · Statistics 2015-01-28 Zhaoran Wang , Quanquan Gu , Yang Ning , Han Liu

We introduce an extension of finite mixture models by incorporating skew-normal distributions within a Hidden Markov Model framework. By assuming a constant transition probability matrix and allowing emission distributions to vary according…

Methodology · Statistics 2025-09-25 Andrea Nigri , Marco Forti , Han Lin Shang

We introduce and study Multi-Quantile estimators for the parameters $( \xi, \sigma, \mu)$ of Generalized Extreme Value (GEV) distributions to provide a robust approach to extreme value modeling. Unlike classical estimators, such as the…

Methodology · Statistics 2025-03-03 Sen Lin , Ao Kong , Robert Azencott

We address two important statistical problems: that of estimating mixtures of multivariate normal distributions and mixtures of $t$-distributions based on univariate projections, and that of quantifying a discrepancy between mixture…

Statistics Theory · Mathematics 2026-04-30 Ricardo Fraiman , Leonardo Moreno , Thomas Ransford

The skew-normal and related families are flexible and asymmetric parametric models suitable for modelling a diverse range of systems. We show that the multivariate maximum of a high-dimensional extended skew-normal random sample has…

Methodology · Statistics 2018-10-02 Boris Beranger , Simone A. Padoan , Yangfan Xu , Scott A. Sisson

This article aims to introduced a new lifetime distribution named as exponentiated xgamma distribution (EXGD). The new generalization obtained from xgamma distribution, a special finite mixture of exponential and gamma distributions. The…

Statistics Theory · Mathematics 2018-10-22 Abhimanyu Singh Yadav , Mahendra Saha , Harsh Tripathi , Sumit Kumar

A mixture of shifted asymmetric Laplace distributions is introduced and used for clustering and classification. A variant of the EM algorithm is developed for parameter estimation by exploiting the relationship with the general inverse…

Methodology · Statistics 2017-10-09 Brian C. Franczak , Ryan P. Browne , Paul D. McNicholas

Recently, Lee and Cha (2015, `On two generalized classes of discrete bivariate distributions', {\it American Statistician}, 221 - 230) proposed two general classes of discrete bivariate distributions. They have discussed some general…

Methodology · Statistics 2018-05-01 Debasis Kundu , Vahid Nekoukhou

A new four-parameter model called the Marshall-Olkin extended generalized Gompertz distribution is introduced. Its hazard rate function can be constant, increasing, decreasing, upside-down bathtub or bathtub-shaped depending on its…

Statistics Theory · Mathematics 2019-04-23 Lazhar Benkhelifa

We comment on the recent paper by Azzalini et al. (2015) on two different distributions proposed in the literature for the modelling of data that have asymmetric and possibly long-tailed clusters. They are referred to as the restricted and…

Statistics Theory · Mathematics 2016-01-06 Geoffrey J. McLachlan , Sharon X. Lee

We introduce a novel family of projected distributions on the circle and the sphere, namely the circular and spherical projected Cauchy distributions, as promising alternatives for modelling circular and spherical data. The circular…

Methodology · Statistics 2024-09-12 Michail Tsagris , Omar Alzeley

Expectation Maximization (EM) is among the most popular algorithms for estimating parameters of statistical models. However, EM, which is an iterative algorithm based on the maximum likelihood principle, is generally only guaranteed to find…

Statistics Theory · Mathematics 2016-08-30 Ji Xu , Daniel Hsu , Arian Maleki

This paper introduces constrained mixtures for continuous distributions, characterized by a mixture of distributions where each distribution has a shape similar to the base distribution and disjoint domains. This new concept is used to…

Machine Learning · Statistics 2015-03-29 Conrado S. Miranda , Fernando J. Von Zuben

This paper proposes a unified class of generalized location-scale mixture of multivariate elliptical distributions and studies integral stochastic orderings of random vectors following such distributions. Given a random vector…

Statistics Theory · Mathematics 2023-02-28 Tong Pu , Yiying Zhang , Chuancun Yin

The generation of 3D molecules requires simultaneously deciding the categorical features~(atom types) and continuous features~(atom coordinates). Deep generative models, especially Diffusion Models (DMs), have demonstrated effectiveness in…

Machine Learning · Computer Science 2023-12-13 Yuxuan Song , Jingjing Gong , Minkai Xu , Ziyao Cao , Yanyan Lan , Stefano Ermon , Hao Zhou , Wei-Ying Ma