Exact and approximate moments of a propagating pulse

2008 ◽  
Vol 55 (19-20) ◽  
pp. 3349-3358 ◽  
Author(s):  
Leon Cohen ◽  
Patrick Loughlin ◽  
Greg Okopal
Keyword(s):  
Approximate Moments

scholarly journals A power approximation for the Kenward and Roger Wald test in the linear mixed model

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254811
Author(s):  
Sarah M. Kreidler ◽  
Brandy M. Ringham ◽  
Keith E. Muller ◽  
Deborah H. Glueck
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Wald Test ◽  
Small Sample ◽  
Power Calculation ◽  
Wald Statistic ◽  
Power Approximation ◽  
Group Randomized Trial ◽  
Approximate Moments ◽  
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We derive a noncentral F power approximation for the Kenward and Roger test. We use a method of moments approach to form an approximate distribution for the Kenward and Roger scaled Wald statistic, under the alternative. The result depends on the approximate moments of the unscaled Wald statistic. Via Monte Carlo simulation, we demonstrate that the new power approximation is accurate for cluster randomized trials and longitudinal study designs. The method retains accuracy for small sample sizes, even in the presence of missing data. We illustrate the method with a power calculation for an unbalanced group-randomized trial in oral cancer prevention.

scholarly journals Approximate moments of extremes

2015 ◽  
Vol 2015 (1) ◽  
Author(s):  
Christopher S Withers ◽  
Saralees Nadarajah
Keyword(s):  
Approximate Moments

Approximate Moments of the Adès Distribution

1989 ◽  
Vol 31 (7) ◽  
pp. 875-883 ◽  
Author(s):  
Philip Holgate
Keyword(s):  
Approximate Moments
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