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Robust clustering from incomplete data is an important topic because, in many practical situations, real data sets are heavy-tailed, asymmetric, and/or have arbitrary patterns of missing observations. Flexible methods and algorithms for…

Methodology · Statistics 2018-11-13 Yuhong Wei , Yang Tang , Paul D. McNicholas

We consider the problem of inferring an unknown number of clusters in replicated multinomial data. Under a model based clustering point of view, this task can be treated by estimating finite mixtures of multinomial distributions with or…

Methodology · Statistics 2023-07-07 Panagiotis Papastamoulis

Mixtures of multivariate normal inverse Gaussian (MNIG) distributions can be used to cluster data that exhibit features such as skewness and heavy tails. However, for cluster analysis, using a traditional finite mixture model framework,…

Methodology · Statistics 2020-05-13 Yuan Fang , Dimitris Karlis , Sanjeena Subedi

We propose a new assumption in outlier detection: Normal data instances are commonly located in the area that there is hardly any fluctuation on data density, while outliers are often appeared in the area that there is violent fluctuation…

Machine Learning · Computer Science 2020-06-09 Ding Liu , Hui Li

As in other estimation scenarios, likelihood based estimation in the normal mixture set-up is highly non-robust against model misspecification and presence of outliers (apart from being an ill-posed optimization problem). A robust…

Methodology · Statistics 2023-12-20 Soumya Chakraborty , Ayanendranath Basu , Abhik Ghosh

Finite mixtures of regressions with fixed covariates are a commonly used model-based clustering methodology to deal with regression data. However, they assume assignment independence, i.e. the allocation of data points to the clusters is…

Methodology · Statistics 2021-04-27 Salvatore D. Tomarchio , Paul D. McNicholas , Antonio Punzo

The time series cluster kernel (TCK) provides a powerful tool for analysing multivariate time series subject to missing data. TCK is designed using an ensemble learning approach in which Bayesian mixture models form the base models. Because…

Machine Learning · Computer Science 2019-07-12 Karl Øyvind Mikalsen , Cristina Soguero-Ruiz , Filippo Maria Bianchi , Arthur Revhaug , Robert Jenssen

Clustering is the process of finding underlying group structures in data. Although mixture model-based clustering is firmly established in the multivariate case, there is a relative paucity of work on matrix variate distributions and none…

Methodology · Statistics 2018-03-06 Michael P. B. Gallaugher , Paul D. McNicholas

This work introduces a family of univariate constrained mixtures of generalized normal distributions (CMGND) where the location, scale, and shape parameters can be constrained to be equal across any subset of mixture components. An…

Methodology · Statistics 2025-06-05 Pierdomenico Duttilo , Stefano Antonio Gattone , Alfred Kume

Semi- and non-parametric mixture of regressions are a very useful flexible class of mixture of regressions in which some or all of the parameters are non-parametric functions of the covariates. These models are, however, based on the…

Methodology · Statistics 2026-01-13 Sphiwe B. Skhosana , Weixin Yao

Clustering is a widely used technique in data mining applications for discovering patterns in underlying data. Most traditional clustering algorithms are limited to handling datasets that contain either numeric or categorical attributes.…

Artificial Intelligence · Computer Science 2007-05-23 Zengyou He , Xiaofei Xu , Shengchun Deng

A model based clustering procedure for data of mixed type, clustMD, is developed using a latent variable model. It is proposed that a latent variable, following a mixture of Gaussian distributions, generates the observed data of mixed type.…

Methodology · Statistics 2015-11-06 Damien McParland , Isobel Claire Gormley

We study the classic $k$-means/median clustering, which are fundamental problems in unsupervised learning, in the setting where data are partitioned across multiple sites, and where we are allowed to discard a small portion of the data by…

Distributed, Parallel, and Cluster Computing · Computer Science 2018-10-12 Jiecao Chen , Erfan Sadeqi Azer , Qin Zhang

Fast and effective unsupervised anomaly detection algorithms have been proposed for categorical data based on the minimum description length (MDL) principle. However, they can be ineffective when detecting anomalies in heterogeneous…

Databases · Computer Science 2020-06-16 James Cheney , Xavier Gombau , Ghita Berrada , Sidahmed Benabderrahmane

Clustering is a widely used technique with a long and rich history in a variety of areas. However, most existing algorithms do not scale well to large datasets, or are missing theoretical guarantees of convergence. This paper introduces a…

Machine Learning · Statistics 2024-10-16 Yijia Zhou , Kyle A. Gallivan , Adrian Barbu

A mixture of multivariate Poisson-log normal factor analyzers is introduced by imposing constraints on the covariance matrix, which resulted in flexible models for clustering purposes. In particular, a class of eight parsimonious mixture…

Methodology · Statistics 2023-11-15 Andrea Payne , Anjali Silva , Steven J. Rothstein , Paul D. McNicholas , Sanjeena Subedi

A new maximum approximate likelihood (ML) estimation algorithm for the mixture of Kent distribution is proposed. The new algorithm is constructed via the BSLM (block successive lower-bound maximization) framework and incorporates manifold…

Computation · Statistics 2017-09-15 Hien D. Nguyen

Modern data-driven and distributed learning frameworks deal with diverse massive data generated by clients spread across heterogeneous environments. Indeed, data heterogeneity is a major bottleneck in scaling up many distributed learning…

Machine Learning · Computer Science 2023-08-23 Amirhossein Reisizadeh , Khashayar Gatmiry , Asuman Ozdaglar

Multiple datasets containing different types of features may be available for a given task. For instance, users' profiles can be used to group users for recommendation systems. In addition, a model can also use users' historical behaviors…

Machine Learning · Computer Science 2016-05-10 Weixiang Shao , Xiaoxiao Shi , Philip S. Yu

A mixture of common skew-t factor analyzers model is introduced for model-based clustering of high-dimensional data. By assuming common component factor loadings, this model allows clustering to be performed in the presence of a large…

Methodology · Statistics 2014-05-05 Paula M. Murray , Paul D. McNicholas , Ryan P. Browne