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Related papers: Functional Models for Time-Varying Random Objects

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This work proposes an algorithmic framework to learn time-varying graphs from online data. The generality offered by the framework renders it model-independent, i.e., it can be theoretically analyzed in its abstract formulation and then…

Machine Learning · Computer Science 2022-05-25 Alberto Natali , Elvin Isufi , Mario Coutino , Geert Leus

The construction of valid and flexible cross-covariance functions is a fundamental task for modeling multivariate space-time data arising from climatological and oceanographical phenomena. Indeed, a suitable specification of the covariance…

Statistics Theory · Mathematics 2017-11-23 Alfredo Alegría , Emilio Porcu , Reinhard Furrer , Jorge Mateu

The Fr\'echet regression is a useful method for modeling random objects in a general metric space given Euclidean covariates. However, the conventional approach could be sensitive to outlying objects in the sense that the distance from the…

Computation · Statistics 2026-01-21 Hao Li , Shonosuke Sugasawa , Shota Katayama

The existing Fr\'echet regression is actually defined within a linear framework, since the weight function in the Fr\'echet objective function is linearly defined, and the resulting Fr\'echet regression function is identified to be a linear…

Methodology · Statistics 2024-03-28 Lu Lin , Ze Chen

Standard geostatistical models assume second order stationarity of the underlying Random Function. In some instances, there is little reason to expect the spatial dependence structure to be stationary over the whole region of interest. In…

Methodology · Statistics 2014-12-04 Francky Fouedjio , Nicolas Desassis , Jacques Rivoirard

This paper focuses on the analysis of spatially correlated functional data. The between-curve correlation is modeled by correlating functional principal component scores of the functional data. We propose a Spatial Principal Analysis by…

Statistics Theory · Mathematics 2014-11-19 Chong Liu , Surajit Ray , Giles Hooker

Covariance functions are the core of spatial statistics, stochastic processes, machine learning as well as many other theoretical and applied disciplines. The properties of the covariance function at small and large distances determine the…

Statistics Theory · Mathematics 2023-01-16 Alfredo Alegría , Fabián Ramírez , Emilio Porcu

As a growing number of problems involve variables that are random objects, the development of models for such data has become increasingly important. This paper introduces a novel varying-coefficient Fr\'echet regression model that extends…

Methodology · Statistics 2025-09-16 Yanzhao Wang , Jianqiang Zhang , Wangli Xu

Mixed spatial autoregressive (SAR) models with numerical covariates have been well studied. However, as non-numerical data, such as functional data and compositional data, receive substantial amounts of attention and are applied to…

Applications · Statistics 2018-11-08 Huiwen Wang , Tingting Huang , Shanshan Wang

Fr\'echet regression has emerged as a promising approach for regression analysis involving non-Euclidean response variables. However, its practical applicability has been hindered by its reliance on ideal scenarios with abundant and…

Methodology · Statistics 2023-10-26 Kyunghee Han , Dogyoon Song

Detecting structural changes in functional data is a prominent topic in statistical literature. However not all trends in the data are important in applications, but only those of large enough influence. In this paper we address the problem…

Statistics Theory · Mathematics 2019-11-19 Holger Dette , Tim Kutta

Multivariate space-time data are increasingly available in various scientific disciplines. When analyzing these data, one of the key issues is to describe the multivariate space-time dependencies. Under the Gaussian framework, one needs to…

Methodology · Statistics 2016-02-10 Marc Bourotte , Denis Allard , Emilio Porcu

We develop a statistical framework for conducting inference on collections of time-varying covariance operators (covariance flows) over a general, possibly infinite dimensional, Hilbert space. We model the intrinsically non-linear structure…

Methodology · Statistics 2024-06-25 Leonardo V. Santoro , Victor M. Panaretos

This paper examines robust functional data analysis for discretely observed data, where the underlying process encompasses various distributions, such as heavy tail, skewness, or contaminations. We propose a unified robust concept of…

Methodology · Statistics 2023-05-26 Lingxuan Shao , Fang Yao

We propose a flexible regression framework to model the conditional distribution of multilevel generalized multivariate functional data of potentially mixed type, e.g. binary and continuous data. We make pointwise parametric distributional…

Methodology · Statistics 2024-07-31 Alexander Volkmann , Nikolaus Umlauf , Sonja Greven

Matrix-valued covariance functions are crucial to geostatistical modeling of multivariate spatial data. The classical assumption of symmetry of a multivariate covariance function is overlay restrictive and has been considered as unrealistic…

Statistics Theory · Mathematics 2017-11-28 Alfredo Alegría , Emilio Porcu , Reinhard Furrer

Data can be assumed to be continuous functions defined on an infinite-dimensional space for many phenomena. However, the infinite-dimensional data might be driven by a small number of latent variables. Hence, factor models are relevant for…

Methodology · Statistics 2022-05-18 Israel Martínez-Hernández , Jesús Gonzalo , Graciela González-Farías

Autocovariance of the error term in a time series model plays a key role in the estimation and inference for the model that it belongs to. Typically, some arbitrary parametric structure is assumed upon the error to simplify the estimation,…

Methodology · Statistics 2022-10-17 Yoon Bae Jun , Chae Young Lim , Kun Ho Kim

This paper proposes a new method for determining similarity and anomalies between time series, most practically effective in large collections of (likely related) time series, by measuring distances between structural breaks within such a…

Machine Learning · Computer Science 2020-12-01 Nick James , Max Menzies , Lamiae Azizi , Jennifer Chan

Motivated by recent work studying massive imaging data in the neuroimaging literature, we propose multivariate varying coefficient models (MVCM) for modeling the relation between multiple functional responses and a set of covariates. We…

Statistics Theory · Mathematics 2013-02-19 Hongtu Zhu , Runze Li , Linglong Kong