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In recent years, conditional copulas, that allow dependence between variables to vary according to the values of one or more covariates, have attracted increasing attention. In high dimension, vine copulas offer greater flexibility compared…

Methodology · Statistics 2021-09-24 Rosario Barone , Luciana Dalla Valle

Prediction is a classic challenge in spatial statistics and the inclusion of spatial covariates can greatly improve predictive performance when incorporated into a model with latent spatial effects. It is desirable to develop flexible…

Methodology · Statistics 2025-02-24 Alex Ziyu Jiang , Jon Wakefield

We develop a numerical method suitable for gravitational collapse based on Cauchy evolution with an ingoing characteristic boundary. Unlike similar methods proposed recently (Ripley; Bieri, Garfinkle & Yau 2019/20), the numerical grid…

General Relativity and Quantum Cosmology · Physics 2020-12-04 Oliver Rinne

Motivated by investigating spatio-temporal patterns of the distribution of continuous variables, we consider describing the conditional distribution function of the response variable incorporating spatio-temporal components given…

We introduce a new family of copula densities constructed from univariate distributions on $[0,1]$. Although our construction is structurally simple, the resulting family is versatile: it includes both smooth and irregular examples, and…

Statistics Theory · Mathematics 2025-10-01 Michaël Lalancette , Robert Zimmerman

Several collective risk models have recently been proposed by relaxing the widely used but controversial assumption of independence between claim frequency and severity. Approaches include the bivariate copula model, random effect model,…

Applications · Statistics 2019-06-11 Rosy Oh , Jae Youn Ahn , Woojoo Lee

Spatial modelling often uses Gaussian random fields to capture the stochastic nature of studied phenomena. However, this approach incurs significant computational burdens (O(n3)), primarily due to covariance matrix computations. In this…

Methodology · Statistics 2024-04-22 Joaquin Cavieres , Paula Moraga , Cole C. Monnahan

The gamma distribution is a useful model for small area prediction of a skewed response variable. We study the use of the gamma distribution for small area prediction. We emphasize a model, called the gamma-gamma model, in which the area…

Methodology · Statistics 2023-01-18 Yanghyeon Cho , Emily Berg

The continuous extension of a discrete random variable is amongst the computational methods used for estimation of multivariate normal copula-based models with discrete margins. Its advantage is that the likelihood can be derived…

Methodology · Statistics 2014-11-10 Aristidis K. Nikoloulopoulos

We present a constructive approach to Bernstein copulas with an admissible discrete skeleton in arbitrary dimensions when the underlying marginal grid sizes are smaller than the number of observations. This prevents an overfitting of the…

Risk Management · Quantitative Finance 2021-03-04 Dietmar Pfeifer , Olena Ragulina

Copulas are essential tools in statistics and probability theory, enabling the study of the dependence structure between random variables independently of their marginal distributions. Among the various types of copulas, Ratio-Type Copulas…

Statistics Theory · Mathematics 2025-05-21 Ziad Adwan , Nicola Sottocornola

Current astrophysical models of the interstellar medium assume that small scale variation and noise can be modelled as Gaussian random fields or simple transformations thereof, such as lognormal. We use topological methods to investigate…

Applications · Statistics 2017-03-22 Robin Henderson , Irina Makarenko , Paul Bushby , Andrew Fletcher , Anvar Shukurov

The majority of model-based clustering techniques is based on multivariate Normal models and their variants. In this paper copulas are used for the construction of flexible families of models for clustering applications. The use of copulas…

Methodology · Statistics 2018-02-16 Ioannis Kosmidis , Dimitris Karlis

In medical studies, it is common the presence of a fraction of patients who do not experience the event of interest. These patients are people who are not at risk of the event or are patients who were cured during the research. The…

We develop a class of nearest-neighbor mixture models that provide direct, computationally efficient, probabilistic modeling for non-Gaussian geospatial data. The class is defined over a directed acyclic graph, which implies conditional…

Methodology · Statistics 2022-06-28 Xiaotian Zheng , Athanasios Kottas , Bruno Sansó

Copulas provide a modular parameterization of multivariate distributions that decouples the modeling of marginals from the dependencies between them. Gaussian Mixture Copula Model (GMCM) is a highly flexible copula that can model many kinds…

Methodology · Statistics 2021-09-29 Siva Rajesh Kasa , Vaibhav Rajan

We tackle the modeling of threshold exceedances in asymptotically independent stochastic processes by constructions based on Laplace random fields. These are defined as Gaussian random fields scaled with a stochastic variable following an…

Methodology · Statistics 2016-03-09 Thomas Opitz

The paper revisits the $\alpha$--regression framework for compositional data. The model uses a flexible power transformation parameterized by $\alpha$ to interpolate between raw data analysis and log--ratio methods, naturally handling zeros…

Methodology · Statistics 2026-05-14 Michail Tsagris , Yannis Pantazis

The direct Gaussian copula model with discrete marginal distributions is an appealing data-analytic tool but poses difficult computational challenges due to its intractable likelihood. A number of approximations/surrogates for the…

Methodology · Statistics 2021-03-08 John Hughes

Cooperative online scalar field mapping is an important task for multi-robot systems. Gaussian process regression is widely used to construct a map that represents spatial information with confidence intervals. However, it is difficult to…

Robotics · Computer Science 2024-01-24 Tianyi Ding , Ronghao Zheng , Senlin Zhang , Meiqin Liu