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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Professor Brian Cullis

2012

Data

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

On The Design Of Early Generation Variety Trials With Correlated Data, Brian Cullis, A Smith, N. Coombes Nov 2012

On The Design Of Early Generation Variety Trials With Correlated Data, Brian Cullis, A Smith, N. Coombes

Professor Brian Cullis

This article considers the design of early generation variety trials with a prespecified spatial correlation structure and introduces a new class of partially replicated designs called p-rep designs in which the plots of standard varieties are replaced by additional plots of test lines. We show how efficient p-rep designs can be readily generated using the modified Reactive TABU search algorithm. The expected and realized genetic gain of p-rep and grid plot designs is compared in a simulation study.


The Analysis Of Longitudinal Data Using Mixed Model L-Splines, S. Welham, Brian Cullis, M. Kenward, R Thompson Nov 2012

The Analysis Of Longitudinal Data Using Mixed Model L-Splines, S. Welham, Brian Cullis, M. Kenward, R Thompson

Professor Brian Cullis

L-splines are a large family of smoothing splines defined in terms of a linear differential operator. This article develops L-splines within the context of linear mixed models and uses the resulting mixed model L-spline to analyze longitudinal data from a grassland experiment. In the spirit of time-series analysis, a periodic mixed model L-spline is developed, which partitions data into a smooth periodic component plus smooth long-term trend.