Carsten H. Botts

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We model sparse functional data from multiple subjects with a mixed-effects regression spline. In this model, the expected values for any subject (conditioned on the random effects) can be written as the sum of a population curve and a subject-specific deviate from this population curve. The population curve and the subject-specific deviates are both(More)
This article describes an application of small area estimation in a survey conducted in the Rathbun Lake Watershed in Iowa (USA). The estimator considered is an extension of the mixed effects regression model of Battese, Harter and Fuller (1988). From a sample of 183 plots in the watershed, erosion from four sources as well as total erosion are estimated(More)
This article describes the sampling design, survey methodology and findings of a natural resources survey conducted in the Rathbun Lake Watershed in Southern Iowa in 1999-2000. The goal of the survey was to quantify the erosion from all sources on agricultural lands and the ecological health of streams for each of 61 subwatersheds in the area. A total of(More)
The acceptance-rejection algorithm is often used to sample from non-standard distributions. For this algorithm to be efficient, however, the user has to create a hat function that majorizes and closely matches the density of the distribution to be sampled from. There are many methods for automatically creating such hat functions, but these methods require(More)
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