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Discrimination between non-stationarity and long-range dependency is a difficult and long-standing issue in modelling financial time series. This paper uses an adaptive spectral technique which jointly models the non-stationarity and…

Statistical Finance · Quantitative Finance 2019-02-12 Nick James , Roman Marchant , Richard Gerlach , Sally Cripps

Many physical datasets are generated by collections of instruments that make measurements at regular time intervals. For such regular monitoring data, we extend the framework of half-spectral covariance functions to the case of…

Methodology · Statistics 2020-07-23 Christopher J. Geoga , Mihai Anitescu , Michael L. Stein

We aim at analyzing geostatistical and areal data observed over irregularly shaped spatial domains and having a distribution within the exponential family. We propose a generalized additive model that allows to account for spatially-varying…

Methodology · Statistics 2016-04-22 Matthieu Wilhelm , Laura M. Sangalli

In a wide range of applications, the stochastic properties of the observed time series change over time. The changes often occur gradually rather than abruptly: the prop- erties are (approximately) constant for some time and then slowly…

Methodology · Statistics 2014-03-18 Michael Vogt , Holger Dette

Observing system simulation experiments (OSSEs) have been widely used as a rigorous and cost-effective way to guide development of new observing systems, and to evaluate the performance of new data assimilation algorithms. Nature runs…

Methodology · Statistics 2018-09-05 Pulong Ma , Emily L. Kang , Amy Braverman , Hai Nguyen

It is no secret that statistical modelling often involves making simplifying assumptions when attempting to study complex stochastic phenomena. Spatial modelling of extreme values is no exception, with one of the most common such…

Applications · Statistics 2025-05-05 Lydia Kakampakou , Emma S. Simpson , Jennifer L. Wadsworth

Gaussian processes and random fields have a long history, covering multiple approaches to representing spatial and spatio-temporal dependence structures, such as covariance functions, spectral representations, reproducing kernel Hilbert…

Methodology · Statistics 2022-10-18 Finn Lindgren , David Bolin , Håvard Rue

Nonstationary and non-Gaussian spatial data are common in various fields, including ecology (e.g., counts of animal species), epidemiology (e.g., disease incidence counts in susceptible regions), and environmental science (e.g.,…

Methodology · Statistics 2024-04-01 Remy MacDonald , Benjamin Seiyon Lee

This paper studies a risk minimization problem with decision dependent data distribution. The problem pertains to the performative prediction setting in which a trained model can affect the outcome estimated by the model. Such dependency…

Optimization and Control · Mathematics 2025-01-07 Qiang Li , Hoi-To Wai

A flexible model for non-stationary Gaussian random fields on hypersurfaces is introduced.The class of random fields on curves and surfaces is characterized by an amplitude spectral density of a second order elliptic differential…

Numerical Analysis · Mathematics 2024-12-02 Erik Jansson , Annika Lang , Mike Pereira

Neural radiance fields with stochasticity have garnered significant interest by enabling the sampling of plausible radiance fields and quantifying uncertainty for downstream tasks. Existing works rely on the independence assumption of…

Computer Vision and Pattern Recognition · Computer Science 2023-10-05 Songlin Wei , Jiazhao Zhang , Yang Wang , Fanbo Xiang , Hao Su , He Wang

In a wide range of applications, the stochastic properties of the observed time series change over time. The changes often occur gradually rather than abruptly: the properties are (approximately) constant for some time and then slowly start…

Methodology · Statistics 2015-04-03 Michael Vogt , Holger Dette

Sensor simulation is pivotal for scalable validation of autonomous driving systems, yet existing Neural Radiance Fields (NeRF) based methods face applicability and efficiency challenges in industrial workflows. This paper introduces a…

Computer Vision and Pattern Recognition · Computer Science 2025-03-18 Xianming Zeng , Sicong Du , Qifeng Chen , Lizhe Liu , Haoyu Shu , Jiaxuan Gao , Jiarun Liu , Jiulong Xu , Jianyun Xu , Mingxia Chen , Yiru Zhao , Peng Chen , Yapeng Xue , Chunming Zhao , Sheng Yang , Qiang Li

The prevalence of spatially referenced multivariate data has impelled researchers to develop a procedure for the joint modeling of multiple spatial processes. This ordinarily involves modeling marginal and cross-process dependence for any…

Methodology · Statistics 2020-07-10 Ghulam A. Qadir , Ying Sun

Generative modeling of spatio-temporal fields is crucial for a variety of applications, including stochastic weather generators and climate-model surrogates. However, many such fields exhibit complex dependence structures that vary across…

Methodology · Statistics 2026-05-06 Carrie J. Lei-Cramer , Jian Cao , Matthias Katzfuss

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

Spatial processes with nonstationary and anisotropic covariance structure are often used when modelling, analysing and predicting complex environmental phenomena. Such processes may often be expressed as ones that have stationary and…

Methodology · Statistics 2020-04-06 Andrew Zammit-Mangion , Tin Lok James Ng , Quan Vu , Maurizio Filippone

We introduce an adaptive regularization approach. In contrast to conventional Tikhonov regularization, which specifies a fixed regularization operator, we estimate it simultaneously with parameters. From a Bayesian perspective we estimate…

Computer Vision and Pattern Recognition · Computer Science 2009-06-19 Andriy Myronenko , Xubo Song

The paper introduces a new meshfree pseudospectral method based on Gaussian radial basis functions (RBFs) collocation to solve fractional Poisson equations. Hypergeometric functions are used to represent the fractional Laplacian of Gaussian…

Numerical Analysis · Mathematics 2024-01-01 Xiaochuan Tian , Yixuan Wu , Yanzhi Zhang

Scalable spatial GPs for massive datasets can be built via sparse Directed Acyclic Graphs (DAGs) where a small number of directed edges is sufficient to flexibly characterize spatial dependence. The DAG can be used to devise fast algorithms…

Methodology · Statistics 2025-03-31 Michele Peruzzi , Sudipto Banerjee , David B. Dunson , Andrew O. Finley