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Peter A. Tait

Publications and source records attributed to Peter A. Tait.

2 recordsLinked to original sources

Four Skewed Tensor Distributions

With the rise of the "big data" phenomenon in recent years, data is coming in many different complex forms. One example of this is multi-way data that come in the form of higher-order tensors such as coloured images and movie clips. Although there has been a recent rise in models for looking at the simple case of three-way data in the form of matrices, there is a relative paucity of higher-order tensor variate methods. The most common tensor distribution in the literature is the tensor variate normal distribution; however, its use can be problematic if the data exhibit skewness or outliers. Herein, we develop four skewed tensor variate distributions which to our knowledge are the first skewed tensor distributions to be proposed in the literature, and are able to parameterize both skewness and tail weight. Properties and parameter estimation are discussed, and real and simulated data are used for illustration.

stat.ME↗

Clustering Higher Order Data: An Application to Pediatric Multi-variable Longitudinal Data

Physical activity levels are an important predictor of cardiovascular health and increasingly being measured by sensors, like accelerometers. Accelerometers produce rich multivariate data that can inform important clinical decisions related to individual patients and public health. The CHAMPION study, a study of youth with chronic inflammatory conditions, aims to determine the links between heart health, inflammation, physical activity, and fitness. The accelerometer data from CHAMPION is represented as 4-dimensional arrays, and a finite mixture of multidimensional arrays model is developed for clustering. The use of model-based clustering for multidimensional arrays has thus far been limited to two-dimensional arrays, i.e., matrices or order-two tensors, and the work in this paper can also be seen as an approach for clustering D-dimensional arrays for D > 2 or, in other words, for clustering order-D tensors.

stat.ME↗