no code implementations • 13 Nov 2022 • Carlos Llosa-Vite, Ranjan Maitra
Statistical analysis of tensor-valued data has largely used the tensor-variate normal (TVN) distribution that may be inadequate when data comes from distributions with heavier or lighter tails.
no code implementations • 9 Nov 2021 • Fan Dai, Karin S. Dorman, Somak Dutta, Ranjan Maitra
Data on high-dimensional spheres arise frequently in many disciplines either naturally or as a consequence of preliminary processing and can have intricate dependence structure that needs to be understood.
no code implementations • 19 Oct 2021 • Yifan Zhu, Fan Dai, Ranjan Maitra
We develop methodology for three-dimensional (3D) radial visualization (RadViz) of multidimensional datasets.
no code implementations • 24 Sep 2021 • Bishoy Dawood, Carlos Llosa-Vite, Geoffrey Z. Thompson, Barbara K. Lograsso, Lauren K. Claytor, John Vanderkolk, William Meeker, Ranjan Maitra, Ashraf Bastawros
In this study, a statistical analysis comparison protocol was applied to a set of 3D topological images of fractured surface pairs and their replicas to provide confidence in the quantitative statistical comparison between fractured items and their replicas.
1 code implementation • 30 Mar 2021 • Emily M. Goren, Ranjan Maitra
We compare our approximate algorithm to the corresponding full expectation-maximization (EM) approach that considers the missing values in the incomplete data set and makes a missing at random (MAR) assumption, as well as case deletion and imputation methods.
1 code implementation • 6 Feb 2021 • Wei-Chen Chen, Ranjan Maitra
Finally, the value of our suggested approach in low-signal and single-subject fMRI studies is illustrated on a sports imagination experiment that is often used to detect awareness and improve treatment in patients in persistent vegetative state (PVS).
no code implementations • 18 Dec 2020 • Carlos Llosa-Vite, Ranjan Maitra
Fitting regression models with many multivariate responses and covariates can be challenging, but such responses and covariates sometimes have tensor-variate structure.
no code implementations • 6 Jun 2020 • Karin S. Dorman, Ranjan Maitra
Mining clusters from data is an important endeavor in many applications.
no code implementations • 20 Apr 2020 • Geoffrey Z. Thompson, Ranjan Maitra
We introduce CatSIM, a new similarity metric for binary and multinary two- and three-dimensional images and volumes.
no code implementations • 12 Mar 2020 • Karl T. Pazdernik, Ranjan Maitra
Spatial prediction is commonly achieved under the assumption of a Gaussian random field (GRF) by obtaining maximum likelihood estimates of parameters, and then using the kriging equations to arrive at predicted values.
no code implementations • 12 Mar 2020 • Souradeep Chattopadhyay, Steven D. Kawaler, Ranjan Maitra
A nonparametric bootstrap procedure was also used to estimate the confidence of each of our group assignments.
no code implementations • 27 Jul 2019 • Fan Dai, Somak Dutta, Ranjan Maitra
This paper proposes a novel profile likelihood method for estimating the covariance parameters in exploratory factor analysis of high-dimensional Gaussian datasets with fewer observations than number of variables.
no code implementations • 22 Jul 2019 • Geoffrey Z. Thompson, Ranjan Maitra, William Q. Meeker, Ashraf Bastawros
Matrix-variate distributions can intuitively model the dependence structure of matrix-valued observations that arise in applications with multivariate time series, spatio-temporal or repeated measures.
no code implementations • 21 Apr 2019 • Nicholas S. Berry, Ranjan Maitra
The $K$-means algorithm is extended to allow for partitioning of skewed groups.
no code implementations • 6 Apr 2019 • Yifan Zhu, Fan Dai, Ranjan Maitra
We develop methodology for visualization of labeled mixed-featured datasets.
1 code implementation • 24 May 2018 • Israel Almodóvar-Rivera, Ranjan Maitra
Here, we develop a distribution-free fully-automated syncytial clustering algorithm that can be used with $k$-means and other algorithms.
1 code implementation • 23 Feb 2018 • Andrew Lithio, Ranjan Maitra
We also provide initialization strategies for our algorithm and methods to estimate the number of groups in the dataset.
no code implementations • 23 Dec 2017 • Anna D. Peterson, Arka P. Ghosh, Ranjan Maitra
For instance, hierarchical clustering identifies groups in a tree-like structure but suffers from computational complexity in large datasets while $K$-means clustering is efficient but designed to identify homogeneous spherically-shaped clusters.
Ranked #7 on Speech Synthesis on North American English
no code implementations • 6 Dec 2017 • Alejandro Murua-Sazo, Ranjan Maitra
The Ising model is important in statistical modeling and inference in many applications, however its normalizing constant, mean number of active vertices and mean spin interaction -- quantities needed in inference -- are computationally intractable.