English
Related papers

Related papers: An improved EM algorithm for solving MLE in constr…

200 papers

We study modeling and inference with the Elliptical Gamma Distribution (EGD). We consider maximum likelihood (ML) estimation for EGD scatter matrices, a task for which we develop new fixed-point algorithms. Our algorithms are efficient and…

Computation · Statistics 2018-06-04 Reshad Hosseini , Suvrit Sra , Lucas Theis , Matthias Bethge

\hspace{2mm} Diffusion-weighted magnetic resonance imaging (dMRI) of the brain offers unique capabilities including noninvasive probing of tissue microstructure and structural connectivity. It is widely used for clinical assessment of…

Image and Video Processing · Electrical Eng. & Systems 2025-12-30 Davood Karimi , Simon K. Warfield

Diffusion-based generative models (DBGMs) perturb data to a target noise distribution and reverse this process to generate samples. The choice of noising process, or inference diffusion process, affects both likelihoods and sample quality.…

Machine Learning · Computer Science 2023-03-06 Raghav Singhal , Mark Goldstein , Rajesh Ranganath

Computational imaging is crucial in many disciplines from autonomous driving to life sciences. However, traditional model-driven and iterative methods consume large computational power and lack scalability for imaging. Deep learning (DL) is…

Image and Video Processing · Electrical Eng. & Systems 2024-08-26 Weiru Fan , Xiaobin Tang , Yiyi Liao , Da-Wei Wang

A distributed adaptive algorithm is proposed to solve a node-specific parameter estimation problem where nodes are interested in estimating parameters of local interest, parameters of common interest to a subset of nodes and parameters of…

Computers and Society · Computer Science 2023-07-19 Jorge Plata-Chaves , Nikola Bogdanovic , Kostas Berberidis

Multi-contrast magnetic resonance imaging (MRI) is the most common management tool used to characterize neurological disorders based on brain tissue contrasts. However, acquiring high-resolution MRI scans is time-consuming and infeasible…

Image and Video Processing · Electrical Eng. & Systems 2023-06-08 Ye Mao , Lan Jiang , Xi Chen , Chao Li

We consider distributed estimation of the inverse covariance matrix, also called the concentration or precision matrix, in Gaussian graphical models. Traditional centralized estimation often requires global inference of the covariance…

Machine Learning · Statistics 2015-06-15 Zhaoshi Meng , Dennis Wei , Ami Wiesel , Alfred O. Hero

Diffusion tensor imaging (DTI) is a prevalent neuroimaging tool in analyzing the anatomical structure. The distinguishing feature of DTI is that the voxel-wise variable is a 3x3 positive definite matrix other than a scalar, describing the…

Methodology · Statistics 2021-03-30 Zhou Lan

Diffusion MRI (dMRI) is a unique imaging technique for in vivo characterization of tissue microstructure and white matter pathways. However, its relatively long acquisition time implies greater motion artifacts when imaging, for example,…

Medical Physics · Physics 2020-02-26 Yoonmi Hong , Wei-Tang Chang , Geng Chen , Ye Wu , Weili Lin , Dinggang Shen , Pew-Thian Yap

Joint modeling of diffusion and relaxation has seen growing interest due to its potential to provide complementary information about tissue microstructure. For brain white matter, we designed an optimal diffusion-relaxometry MRI protocol…

Diffusion MRI (dMRI) is an important neuroimaging technique with high acquisition costs. Deep learning approaches have been used to enhance dMRI and predict diffusion biomarkers through undersampled dMRI. To generate more comprehensive raw…

Image and Video Processing · Electrical Eng. & Systems 2024-07-11 Juanhua Zhang , Ruodan Yan , Alessandro Perelli , Xi Chen , Chao Li

Maximum likelihood estimation (MLE) is one of the most important methods in machine learning, and the expectation-maximization (EM) algorithm is often used to obtain maximum likelihood estimates. However, EM heavily depends on initial…

Machine Learning · Statistics 2017-11-21 Hideyuki Miyahara , Koji Tsumura , Yuki Sughiyama

The diffusion least-mean square (dLMS) algorithms have attracted much attention owing to its robustness for distributed estimation problems. However, the performance of such filters may change when they are implemented for suppressing…

Systems and Control · Computer Science 2017-08-09 Lu Lu , Haiquan Zhao

This paper presents novel single and multi-shell sampling schemes for diffusion MRI. In diffusion MRI, it is paramount that the number of samples is as small as possible in order that scan times are practical in a clinical setting. The…

Signal Processing · Electrical Eng. & Systems 2019-02-01 Alice P. Bates , Zubair Khalid , Jason D. McEwen , Rodney A. Kennedy , Alessandro Daducci , Erick J. Canales-Rodríguez

Kernel density estimation (KDE) is one of the most widely used nonparametric density estimation methods. The fact that it is a memory-based method, i.e., it uses the entire training data set for prediction, makes it unsuitable for most…

Machine Learning · Computer Science 2022-08-08 Joseph A. Gallego , Juan F. Osorio , Fabio A. González

This work introduces a compartment-based model for apparent soma and neurite density imaging (SANDI) using non-invasive diffusion-weighted MRI (DW-MRI). The existing conjecture in brain microstructure imaging trough DW-MRI presents water…

Diffusion models (DMs) are a class of generative machine learning methods that sample a target distribution by transforming samples of a trivial (often Gaussian) distribution using a learned stochastic differential equation. In standard…

Statistical Mechanics · Physics 2024-08-15 Luke Causer , Grant M. Rotskoff , Juan P. Garrahan

The trimming scheme with a prefixed cutoff portion is known as a method of improving the robustness of statistical models such as multivariate Gaussian mixture models (MG- MMs) in small scale tests by alleviating the impacts of outliers.…

Computation and Language · Computer Science 2014-05-20 Dalei Wu , Haiqing Wu

Self-diffusion coefficients, $D^*$, are routinely estimated from molecular dynamics simulations by fitting a linear model to the observed mean-squared displacements (MSDs) of mobile species. MSDs derived from simulation exhibit statistical…

Statistical Mechanics · Physics 2026-01-05 Andrew R. McCluskey , Samuel W. Coles , Benjamin J. Morgan

Diffusion Models (DMs) are powerful generative models that add Gaussian noise to the data and learn to remove it. We wanted to determine which noise distribution (Gaussian or non-Gaussian) led to better generated data in DMs. Since DMs do…

Machine Learning · Computer Science 2023-04-13 Alexia Jolicoeur-Martineau , Kilian Fatras , Ke Li , Tal Kachman