Carl Frederick

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Numerical and computer-graphic methods for conformal image mapping between two simply connected regions are described. The immediate motivation for this application is that the visual field is represented in the brain by mappings which are, at least approximately, conformal. Thus, to simulate the imaging properties of the human visual system (and perhaps(More)
We examine trends over time in the proportion of children below the modal grade for their age (BMG), a proxy for grade retention, and in the effects of its demographic and socioeconomic correlates. We estimate a logistic regression model with partial constraints predicting BMG using the annual October school enrollment supplements of the Current Population(More)
We describe a 3D surface-tracking algorithm that is used to detect the interior laminar surfaces of a solid shell. Each of these surfaces is called a “peel”. Successive peels may be generated, thus representing the solid shell by its tangential layers. This algorithm is based on voxel surface-tracking methods and solves the problems associated with(More)
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