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Motivated by Tucker tensor decomposition, this paper imposes low-rank structures to the column and row spaces of coefficient matrices in a multivariate infinite-order vector autoregression (VAR), which leads to a supervised factor model…

Methodology · Statistics 2023-12-04 Feiqing Huang , Kexin Lu , Guodong Li

The primate heteromodal cortex presents an evident functional modularity at a mesoscopic level, with physiological and anatomical evidence pointing to it as likely substrate of long-term memory. In order to investigate some of its…

Neurons and Cognition · Quantitative Biology 2021-12-09 Carlo Fulvi Mari

We study regularized estimation in high-dimensional longitudinal classification problems, using the lasso and fused lasso regularizers. The constructed coefficient estimates are piecewise constant across the time dimension in the…

Consider semiparametric estimation where a doubly robust estimating function for a low-dimensional parameter is available, depending on two working models. With high-dimensional data, we develop regularized calibrated estimation as a…

Methodology · Statistics 2020-09-28 Satyajit Ghosh , Zhiqiang Tan

Intensive longitudinal data (ILD) collected in mobile health (mHealth) studies contain rich information on multiple outcomes measured frequently over time that have the potential to capture short-term and long-term dynamics. Motivated by an…

Deep Reinforcement Learning has enabled the control of increasingly complex and high-dimensional problems. However, the need of vast amounts of data before reasonable performance is attained prevents its widespread application. We employ…

Machine Learning · Computer Science 2020-04-08 Jan Scholten , Daan Wout , Carlos Celemin , Jens Kober

Let $X=\{X_n: n\in\mathbb{N}\}$ be a long memory linear process with innovations in the domain of attraction of an $\alpha$-stable law $(0<\alpha<2)$. Assume that the linear process $X$ has a bounded probability density function $f(x)$.…

Statistics Theory · Mathematics 2022-10-10 Hui Liu , Fangjun Xu

This paper proposes a novel method for learning highly nonlinear, multivariate functions from examples. Our method takes advantage of the property that continuous functions can be approximated by polynomials, which in turn are representable…

Machine Learning · Computer Science 2020-05-05 Sandor Szedmak , Anna Cichonska , Heli Julkunen , Tapio Pahikkala , Juho Rousu

We study numerical methods for the generalized Langevin equation (GLE) with a positive Prony series memory kernel, in which case the GLE can be written in an extended variable Markovian formalism. We propose a new splitting method that is…

Computational Physics · Physics 2022-05-31 Manh Hong Duong , Xiaocheng Shang

Memory plays a pivotal role in enabling large language model~(LLM)-based agents to engage in complex and long-term interactions, such as question answering (QA) and dialogue systems. While various memory modules have been proposed for these…

Computation and Language · Computer Science 2024-12-23 Ruihong Zeng , Jinyuan Fang , Siwei Liu , Zaiqiao Meng

Dynamic factor models are often estimated by point-estimation methods, disregarding parameter uncertainty. We propose a method accounting for parameter uncertainty by means of posterior approximation, using variational inference. Our…

Methodology · Statistics 2022-10-14 Erik Spånberg

This paper addresses the limitations of large language models in understanding long-term context. It proposes a model architecture equipped with a long-term memory mechanism to improve the retention and retrieval of semantic information…

Computation and Language · Computer Science 2025-05-30 Yue Xing , Tao Yang , Yijiashun Qi , Minggu Wei , Yu Cheng , Honghui Xin

Intersectoral dynamic models with power-law memory are proposed. The equations of open and closed intersectoral models, in which the memory effects are described by the Caputo derivatives of non-integer orders, are derived. We suggest…

Economics · Quantitative Finance 2017-12-27 Valentina V. Tarasova , Vasily E. Tarasov

In high-dimensional classification problems, a commonly used approach is to first project the high-dimensional features into a lower dimensional space, and base the classification on the resulting lower dimensional projections. In this…

Statistics Theory · Mathematics 2025-08-05 Xin Bing , Marten Wegkamp

Longitudinal analysis is important in many disciplines, such as the study of behavioral transitions in social science. Only very recently, feature selection has drawn adequate attention in the context of longitudinal modeling. Standard…

Methodology · Statistics 2016-10-26 Tingyang Xu , Jiangwen Sun , Jinbo Bi

Decision Transformer-based decision-making agents have shown the ability to generalize across multiple tasks. However, their performance relies on massive data and computation. We argue that this inefficiency stems from the forgetting…

Machine Learning · Computer Science 2024-05-30 Jikun Kang , Romain Laroche , Xingdi Yuan , Adam Trischler , Xue Liu , Jie Fu

Traditional Functional Principal Component Analysis typically focuses on densely observed univariate functional data, yet many applications, particularly in longitudinal studies, involve multivariate functional data observed sparsely and…

Methodology · Statistics 2026-03-23 Uche Mbaka , Michelle Carey

Recurrent event time data arise in many studies, including biomedicine, public health, marketing, and social media analysis. High-dimensional recurrent event data involving many event types and observations have become prevalent with…

Methodology · Statistics 2025-04-02 Fangyi Chen , Yunxiao Chen , Zhiliang Ying , Kangjie Zhou

Humans have the ability to accumulate knowledge of new tasks in varying conditions, but deep neural networks often suffer from catastrophic forgetting of previously learned knowledge after learning a new task. Many recent methods focus on…

A generalized Langevin equation is suggested to describe a system with memory($u(t,t') = \frac{1}{\Gamma (\nu )}(t - t')^\nu $) as well as with positive and negative damping. The equation can be transformed into the Fokker-Planck equation…

Physics and Society · Physics 2019-09-11 Peng Wang , Feng-Chun Pan , Jie Huo , Xu-Ming Wang