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Related papers: Modeling Longitudinal Data on Riemannian Manifolds

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Intensive longitudinal studies are becoming progressively more prevalent across many social science areas, especially in psychology. New technologies like smart-phones, fitness trackers, and the Internet of Things make it much easier than…

Methodology · Statistics 2019-06-17 Yunxiao Chen , Siliang Zhang

In this article, we study a partially linear single-index model for longitudinal data under a general framework which includes both the sparse and dense longitudinal data cases. A semiparametric estimation method based on a combination of…

Statistics Theory · Mathematics 2015-07-31 Jia Chen , Degui Li , Hua Liang , Suojin Wang

Dimension reduction for high-dimensional compositional data plays an important role in many fields, where the principal component analysis of the basis covariance matrix is of scientific interest. In practice, however, the basis variables…

Methodology · Statistics 2021-09-13 Jingru Zhang , Wei Lin

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

Functional data, with basic observational units being functions (e.g., curves, surfaces) varying over a continuum, are frequently encountered in various applications. While many statistical tools have been developed for functional data…

Methodology · Statistics 2016-06-10 Jingjing Yang , Hongxiao Zhu , Taeryon Choi , Dennis D. Cox

A typical problem in causal modeling is the instability of model structure learning, i.e., small changes in finite data can result in completely different optimal models. The present work introduces a novel causal modeling algorithm for…

A representation of Gaussian distributed sparsely sampled longitudinal data in terms of predictive distributions for their functional principal component scores (FPCs) maps available data for each subject to a multivariate Gaussian…

Methodology · Statistics 2026-03-13 Álvaro Gajardo , Xiongtao Dai , Hans-Georg Müller

Functional principal component analysis (FPCA) is a key tool in the study of functional data, driving both exploratory analyses and feature construction for use in formal modeling and testing procedures. However, existing methods for FPCA…

Methodology · Statistics 2026-03-24 Caitrin Murphy , Eric Laber , Rhonda Merwin , Brian Reich , Jake Koerner

Modelling longitudinal data is an important yet challenging task. These datasets can be high-dimensional, contain non-linear effects and time-varying covariates. Gaussian process (GP) prior-based variational autoencoders (VAEs) have emerged…

Machine Learning · Computer Science 2024-09-18 Priscilla Ong , Manuel Haußmann , Otto Lönnroth , Harri Lähdesmäki

Mobile health studies often collect multiple within-day self-reported assessments of participants' behavior and well-being on different scales such as physical activity (continuous), pain levels (truncated), mood states (ordinal), and life…

Methodology · Statistics 2023-09-22 Debangan Dey , Rahul Ghosal , Kathleen Merikangas , Vadim Zipunnikov

Motivated by distinct walking patterns in real-world free-living gait data, this paper proposes an innovative curve-based sampling scheme for the analysis of functional data characterized by a mixture of covariance structures. Traditional…

Methodology · Statistics 2025-04-10 Yian Yu , Bo Wang , Jian Qing Shi

Principal component analysis is a versatile tool to reduce dimensionality which has wide applications in statistics and machine learning. It is particularly useful for modeling data in high-dimensional scenarios where the number of…

Methodology · Statistics 2022-08-18 Xiaoyu Hu , Fang Yao

Functional principal component analysis (FPCA) has been widely used to capture major modes of variation and reduce dimensions in functional data analysis. However, standard FPCA based on the sample covariance estimator does not work well in…

Methodology · Statistics 2021-01-19 Guangxing Wang , Sisheng Liu , Fang Han , Chongzhi Di

The article develops marginal models for multivariate longitudinal responses. Overall, the model consists of five regression submodels, one for the mean and four for the covariance matrix, with the latter resulting by considering various…

Methodology · Statistics 2020-12-18 Georgios Papageorgiou

We consider the analysis of continuous repeated measurement outcomes that are collected through time, also known as longitudinal data. A standard framework for analysing data of this kind is a linear Gaussian mixed-effects model within…

Methodology · Statistics 2018-04-10 Özgür Asar , David Bolin , Peter J. Diggle , Jonas Wallin

The advance of modern sensor technologies enables collection of multi-stream longitudinal data where multiple signals from different units are collected in real-time. In this article, we present a non-parametric approach to predict the…

Machine Learning · Statistics 2023-07-04 Seokhyun Chung , Raed Kontar

We propose a supervised principal component regression method for relating functional responses with high dimensional predictors. Unlike the conventional principal component analysis, the proposed method builds on a newly defined expected…

Methodology · Statistics 2023-08-17 Xinyi Zhang , Qiang Sun , Dehan Kong

This paper extends robust principal component analysis (RPCA) to nonlinear manifolds. Suppose that the observed data matrix is the sum of a sparse component and a component drawn from some low dimensional manifold. Is it possible to…

Machine Learning · Computer Science 2019-11-12 He Lyu , Ningyu Sha , Shuyang Qin , Ming Yan , Yuying Xie , Rongrong Wang

Functional data consist of trajectories observed over a continuous domain, such as time, space, or wavelength. Here we consider curves observed on different groups of subjects and propose a Bayesian multi-group functional factor analysis…

Methodology · Statistics 2026-04-02 Xuanye Dai , Anna Gottard , Michele Guindani , Marina Vannucci

Longitudinal data are important in numerous fields, such as healthcare, sociology and seismology, but real-world datasets present notable challenges for practitioners because they can be high-dimensional, contain structured missingness…

Machine Learning · Computer Science 2024-07-01 Maksim Sinelnikov , Manuel Haussmann , Harri Lähdesmäki