no code implementations • 19 Jul 2019 • Peter A. Tait, Paul D. McNicholas, Joyce Obeid
Physical activity levels are an important predictor of cardiovascular health and increasingly being measured by sensors, like accelerometers.
no code implementations • 2 Jul 2019 • Katharine M. Clark, Paul D. McNicholas
Unsupervised classification, or clustering, is a problem often plagued by outliers, yet there is a paucity of work on handling outliers in unsupervised classification.
no code implementations • 12 Mar 2019 • Michael P. B. Gallaugher, Yang Tang, Paul D. McNicholas
A parametrization of the component scale matrices for the mixture of generalized hyperbolic distributions is proposed by including a penalty term in the likelihood constraining the parameters resulting in a flexible model for high dimensional data and a meaningful interpretation.
no code implementations • 26 Jan 2019 • Tyler Roick, Dimitris Karlis, Paul D. McNicholas
The INAR type models can be used in conjunction with existing model-based clustering techniques to cluster discrete-valued time series data.
no code implementations • 23 Dec 2018 • Forrest Paton, Paul D. McNicholas
Functional data analysis is a statistical framework where data are assumed to follow some functional form.
no code implementations • 31 Oct 2018 • Sharon M. McNicholas, Paul D. McNicholas, Daniel A. Ashlock
An evolutionary algorithm (EA) is developed as an alternative to the EM algorithm for parameter estimation in model-based clustering.
1 code implementation • 7 Sep 2018 • Michael P. B. Gallaugher, Paul D. McNicholas
In recent years, data have become increasingly higher dimensional and, therefore, an increased need has arisen for dimension reduction techniques for clustering.
1 code implementation • 22 Jul 2018 • Anjali Silva, Steven J. Rothstein, Paul D. McNicholas, Sanjeena Subedi
Matrix variate distributions offer a natural way to model three-way data and mixtures of matrix variate distributions can be used to cluster three-way data.
Methodology
no code implementations • 13 Apr 2018 • Vanessa S. E. Bierling, Paul D. McNicholas
Amongst other uses, they have been applied for clustering longitudinal data and clustering high-dimensional data.
no code implementations • 13 Feb 2018 • Michael P. B. Gallaugher, Paul D. McNicholas
A mixture of first-order continuous time Markov models is introduced for unsupervised and semi-supervised learning of clickstream data.
1 code implementation • 22 Dec 2017 • Michael P. B. Gallaugher, Paul D. McNicholas
This is perhaps especially true for clustering (unsupervised classification) as well as semi-supervised and supervised classification.
2 code implementations • 30 Nov 2017 • Anjali Silva, Steven J. Rothstein, Paul D. McNicholas, Sanjeena Subedi
The aim of applying mixture model-based clustering in this context is to discover groups of co-expressed genes, which can shed light on biological functions and pathways of gene products.
Methodology Quantitative Methods Computation
no code implementations • 3 Nov 2014 • Utkarsh J. Dang, Antonio Punzo, Paul D. McNicholas, Salvatore Ingrassia, Ryan P. Browne
A family of parsimonious Gaussian cluster-weighted models is presented.
no code implementations • 11 Apr 2014 • Yang Tang, Ryan P. Browne, Paul D. McNicholas
Recent work on clustering of binary data, based on a $d$-dimensional Gaussian latent variable, is extended by incorporating common factor analyzers.
no code implementations • 26 Feb 2014 • Katherine Morris, Antonio Punzo, Paul D. McNicholas, Ryan P. Browne
Mixtures of multivariate contaminated shifted asymmetric Laplace distributions are developed for handling asymmetric clusters in the presence of outliers (also referred to as bad points herein).
no code implementations • 2 Dec 2013 • Utkarsh J. Dang, Paul D. McNicholas
Finite mixtures of regression models offer a flexible framework for investigating heterogeneity in data with functional dependencies.
no code implementations • 26 Nov 2013 • Cristina Tortora, Paul D. McNicholas, Ryan P. Browne
Model-based clustering imposes a finite mixture modelling structure on data for clustering.
no code implementations • 1 Nov 2013 • Brian C. Franczak, Paul D. McNicholas, Ryan P. Browne, Paula M. Murray
A family of parsimonious shifted asymmetric Laplace mixture models is introduced.
no code implementations • 7 Sep 2013 • Sanjeena Subedi, Paul D. McNicholas
Parameter estimation for model-based clustering using a finite mixture of normal inverse Gaussian (NIG) distributions is achieved through variational Bayes approximations.
no code implementations • 28 Aug 2013 • Katherine Morris, Paul D. McNicholas
This mixture model-based approach is based on fitting generalized hyperbolic mixtures on a reduced subspace within the paradigm of model-based clustering, classification, or discriminant analysis.
no code implementations • 16 Aug 2013 • Mateen Shaikh, Paul D. McNicholas, M. Luiza Antonie, T. Brendan Murphy
However, properties of individual association rules restrict the values an interestingness measure can achieve.
no code implementations • 21 Jul 2013 • Paula M. Murray, Paul D. McNicholas, Ryan P. Browne
A mixture of common skew-t factor analyzers model is introduced for model-based clustering of high-dimensional data.
no code implementations • 13 Jul 2013 • Irene Vrbik, Paul D. McNicholas
When some observations are unlabelled, it can be very difficult to \textit{a~priori} choose the optimal level of supervision, and the consequences of a sub-optimal choice can be non-trivial.
no code implementations • 23 Jun 2013 • Sanjeena Subedi, Paul D. McNicholas
Within the family setting, model selection involves choosing the member of the family, i. e., the appropriate covariance structure, in addition to the number of mixture components.
no code implementations • 23 Dec 2012 • Yuhong Wei, Paul D. McNicholas
In mixture model-based clustering applications, it is common to fit several models from a family and report clustering results from only the `best' one.