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Prevalent in many real-world settings such as healthcare, irregular time series are challenging to formulate predictions from. It is difficult to infer the value of a feature at any given time when observations are sporadic, as it could…

Machine Learning · Computer Science 2023-07-26 Taylor W. Killian , Haoran Zhang , Thomas Hartvigsen , Ava P. Amini

This paper considers an approximate dynamic matrix factor model that accounts for the time series nature of the data by explicitly modelling the time evolution of the factors. We study estimation of the model parameters based on the…

Methodology · Statistics 2026-01-08 Matteo Barigozzi , Luca Trapin

We propose a new method named the Conditional Randomization Rank Test (CRRT) for testing conditional independence of a response variable Y and a covariate variable X, conditional on the rest of the covariates Z. The new method generalizes…

Methodology · Statistics 2021-12-02 Yanjie Zhong , Todd Kuffner , Soumendra Lahiri

Mixture models postulate the overall population as a mixture of finite subpopulations with unobserved membership. Fitting mixture models usually requires large sample sizes and combining data from multiple sites can be beneficial. However,…

Methodology · Statistics 2025-12-19 Xiaokang Liu , Rui Duan , Raymond J. Carroll , Yang Ning , Yong Chen

We introduce a new class of multivariate heavy-tailed distributions that are convolutions of heterogeneous multivariate t-distributions. Unlike commonly used heavy-tailed distributions, the multivariate convolution-t distributions embody…

Econometrics · Economics 2024-04-02 Peter Reinhard Hansen , Chen Tong

Sampling distribution, a foundational concept in statistics, is difficult to understand, since we usually have only one realization of the estimator of interest. In this work, we present an innovative method for helping university students…

Other Statistics · Statistics 2021-07-26 Mariela Sued , Marina Valdora

Conditional identity in distribution (Berti et al. (2004)) is a new type of dependence for random variables, which generalizes the well-known notion of exchangeability. In this paper, a class of random sequences, called Generalized Species…

Probability · Mathematics 2008-06-18 Federico Bassetti , Irene Crimaldi , Fabrizio Leisen

Estimating mutual information between continuous random variables is often intractable and extremely challenging for high-dimensional data. Recent progress has leveraged neural networks to optimize variational lower bounds on mutual…

Machine Learning · Computer Science 2020-12-01 Ruizhi Liao , Daniel Moyer , Polina Golland , William M. Wells

This paper concerns the use of the expectation-maximisation (EM) algorithm for inference in partially observed diffusion processes. In this context, a well known problem is that all except a few diffusion processes lack closed-form…

Statistics Theory · Mathematics 2010-08-18 Jimmy Olsson , Jonas Ströjby

We introduce a new broad and exible class of multivariate elliptically symmetric distributions in- cluding the elliptically symmetric logistic and multivariate normal. Various probabilistic properties of the new distribution are studied,…

Probability · Mathematics 2018-10-26 Chuancun Yin , Xiuyan Sha

Ecological Momentary Assessment (EMA) data is organized in multiple levels (per-subject, per-day, etc.) and this particular structure should be taken into account in machine learning algorithms used in EMA like decision trees and its…

Machine Learning · Computer Science 2016-07-07 Gerasimos Spanakis , Gerhard Weiss , Anne Roefs

We show that the orthogonal projection operator onto the range of the adjoint of a linear operator $T$ can be represented as $UT,$ where $U$ is an invertible linear operator. Using this representation we obtain a decomposition of a Normal…

Statistics Theory · Mathematics 2018-02-09 Rajeshwari Majumdar , Suman Majumdar

We propose a novel, succinct, and effective approach for distribution prediction to quantify uncertainty in machine learning. It incorporates adaptively flexible distribution prediction of $\mathbb{P}(\mathbf{y}|\mathbf{X}=x)$ in regression…

Machine Learning · Computer Science 2023-06-21 Xing Yan , Yonghua Su , Wenxuan Ma

In this paper, Bayesian parameter estimation through the consideration of the Maximum A Posteriori (MAP) criterion is revisited under the prism of the Expectation-Maximization (EM) algorithm. By incorporating a sparsity-promoting penalty…

Systems and Control · Computer Science 2015-08-06 Rodrigo Carvajal , Juan C. Agüero , Boris I. Godoy , Dimitrios Katselis

Many problems in computational science and engineering become one-to-many after coarse graining, partial observation, or inverse reconstruction: a resolved state may not determine a unique subgrid forcing, a structural descriptor may not…

Machine Learning · Statistics 2026-05-28 Junfeng Chen

Finite mixture models have been widely used for the modelling and analysis of data from heterogeneous populations. Maximum likelihood estimation of the parameters is typically carried out via the Expectation-Maximization (EM) algorithm. The…

Computation · Statistics 2016-06-08 Sharon X Lee , Kaleb L Lee , Geoffrey J McLachlan

We consider the segmentation problem of univariate distributions from the exponential family with multiple parameters. In segmentation, the choice of the number of segments remains a difficult issue due to the discrete nature of the…

Statistics Theory · Mathematics 2015-03-27 Alice Cleynen , Emilie Lebarbier

Discriminative latent-variable models are typically learned using EM or gradient-based optimization, which suffer from local optima. In this paper, we develop a new computationally efficient and provably consistent estimator for a mixture…

Machine Learning · Computer Science 2013-06-18 Arun Tejasvi Chaganty , Percy Liang

In this paper, we address the problem of conditional modality learning, whereby one is interested in generating one modality given the other. While it is straightforward to learn a joint distribution over multiple modalities using a deep…

Computer Vision and Pattern Recognition · Computer Science 2016-08-29 Gaurav Pandey , Ambedkar Dukkipati

Azzalini (1985) introduced a skew-normal distribution of which normal distribution is a special case. Recently Kundu (2014) introduced a geometric skew-normal distribution and showed that it has certain advantages over Azzalini's…

Methodology · Statistics 2017-06-26 Debasis Kundu