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Related papers: Hierarchical Archimax copulas

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In the context of Higman embeddings of recursive groups into finitely presented groups we suggest an algorithm which uses Higman operations to explicitly constructs the specific recursively enumerable sets of integer sequences arising…

Group Theory · Mathematics 2023-10-18 V. H. Mikaelian

A new method for constructing absolutely continuous two--dimensional copulas by differential equations is presented. The copulas are symmetric with respect to reflection in the opposite diagonal. The support of the copula density may be…

Probability · Mathematics 2019-05-24 Oscar Björnham , Niklas Brännström , Leif Persson

New copulas, based on perturbation theory, are introduced to clarify a \emph{symmetrization} procedure for asymmetric copulas. We give also some properties of the \emph{symmetrized} copula. Finally, we examine families of copulas with a…

Statistics Theory · Mathematics 2021-06-29 Mohamed El Maazouz , Ahmed Sani

Prolongations of a group extension can be studied in a more general situation that we call group extensions of the co-type of a crossed module. Cohomology classification of such extensions is obtained by applying the obstruction theory of…

Category Theory · Mathematics 2015-03-17 Nguyen Tien Quang

Structural hierarchy, in which materials possess distinct features on multiple length scales, is ubiquitous in nature; diverse biological materials, such as bone, cellulose, and muscle, have as many as ten hierarchical levels. Structural…

Soft Condensed Matter · Physics 2019-06-19 Jonathan Michel , Peter Yunker

Over the recent years, Graph Neural Networks have become increasingly popular in network analytic and beyond. With that, their architecture noticeable diverges from the classical multi-layered hierarchical organization of the traditional…

Machine Learning · Computer Science 2021-05-17 Stanislav Sobolevsky

A new approach to the construction of general persistent polyhierarchical classifications is proposed. It is based on implicit description of category polyhierarchy by a generating polyhierarchy of classification criteria. Similarly to…

Artificial Intelligence · Computer Science 2007-05-23 Pavel Babikov , Oleg Gontcharov , Maria Babikova

W-transforms are introduced as uniformity-preserving univariate transformations on the unit interval induced by distribution functions and piecewise strictly monotone functions, and their properties are investigated. When applied…

Methodology · Statistics 2025-10-01 Marius Hofert , Zhiyuan Pang

One of the features inherent in nested Archimedean copulas, also called hierarchical Archimedean copulas, is their rooted tree structure. A nonparametric, rank-based method to estimate this structure is presented. The idea is to represent…

Methodology · Statistics 2013-12-18 Johan Segers , Nathan Uyttendaele

The class of index-mixed copulas is introduced and its properties are investigated. Index-mixed copulas are constructed from given base copulas and a random index vector, and show a rather remarkable degree of analytical tractability. The…

Methodology · Statistics 2023-08-10 Klaus Herrmann , Marius Hofert , Nahid Sadr

A continuous cohomology theory for topological quandles is introduced, and compared to the algebraic theories. Extensions of topological quandles are studied with respect to continuous 2-cocycles, and used to show the differences in second…

Geometric Topology · Mathematics 2020-08-04 Mohamed Elhamdadi , Masahico Saito , Emanuele Zappala

We study stochastic ordering of system lifetimes with dependent and heterogeneous components whose marginal distributions are obtained through transformations of a common baseline. The dependence structure is modeled via Archimedean…

Probability · Mathematics 2026-04-30 Idir Arab , Milto Hadjikyriakou , Paulo Eduardo Oliveira

So called pair copula constructions (PCCs), specifying multivariate distributions only in terms of bivariate building blocks (pair copulas), constitute a flexible class of dependence models. To keep them tractable for inference and model…

Methodology · Statistics 2012-05-23 Jakob Stöber , Harry Joe , Claudia Czado

Any nested Archimedean copula is defined starting from a rooted phylogenetic tree, for which a new class of nonparametric estimators is presented. An estimator from this new class relies on a two-step procedure where first a binary tree is…

Methodology · Statistics 2014-07-02 Nathan Uyttendaele

The uninorms with continuous underlying t-norm and t-conorm are characterized via an extended ordinal sum construction. Using the results of [18], where each uninorm with continuous underlying operations was characterized by properties of…

Rings and Algebras · Mathematics 2015-06-26 Andrea Mesiarova-Zemankova

The concept of intermediate tail dependence is useful if one wants to quantify the degree of positive dependence in the tails when there is no strong evidence of presence of the usual tail dependence. We first review existing studies on…

Methodology · Statistics 2012-12-05 Lei Hua , Harry Joe

We develop an approach to generate random graphs to a target level of assortativity by using copula structures in graphons. Unlike existing random graph generators, we do not use rewiring or binning approaches to generate the desired random…

Social and Information Networks · Computer Science 2025-03-06 Victory Idowu

A fundamental step in the classification of finite-dimensional complex pointed Hopf algebras is the determination of all finite-dimensional Nichols algebras of braided vector spaces arising from groups. The most important class of braided…

Quantum Algebra · Mathematics 2007-05-24 Nicolas Andruskiewitsch , Matias Graña

We introduce and study some general principles and hierarchical properties of expansions and restrictions of structures and their theories The general approach is applied to describe these properties for classes of $\omega$-categorical…

Logic · Mathematics 2025-02-06 Sergey V. Sudoplatov

This is an overview about a method of constructing ccc forcings: Suppose first that a continuous, commutative system of complete embeddings between countable forcings indexed along $\omega_1$ is given. Then its direct limit satisfies ccc by…

Logic · Mathematics 2008-11-07 Bernhard Irrgang