James Steven Marron

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An asymptotic representation of the mean weighted integrated squared error for the kernel based estimator of the hazard rate in the presence of right censored samples is obtained for different bootstrap resam-piing methods. As a consequence, a new bandwidth selector based. on the bootstrap is introduced. Very satisfactory simulations results are obtained in(More)
An important problem in the use of density estimation for data analysis is whether or not observed features, such as bumps are “really there”, as opposed to being artifacts of the natural sampling variability. Here we propose a solution to this problem, in the challenging two dimensional case, using the graphical technique of Signi...cance in Scale Space.(More)
As computer technology has advanced in the last ten years, the ability to acquire copious amounts of physiological data has become much easier. Our laboratory regularly uses radiotelemetry methodology in rodents to acquire nonstop heart rate (HR) and core temperature (Tco) data while animals are exposed to exogenous substances, including air pollutants such(More)
Given a random object on a stratified space embedded in a numerical space, often times the extrinsic sample means stick to a stratum that is closest to the population mean of the corresponding probability distribution in the ambient numerical space via this embedding. In the case of an open book, the limiting distribution of the extrinsic sample means(More)
This paper develops a methodology for ...nding which features in a noisy image are strong enough to be distinguished from background noise. It is based on scale space, i.e. a family of smooths of the image. Pixel locations having statistically signi...cant gradient and/or curvature are highlighted by colored symbols. The gradient version is enhanced by(More)
Acoustic Radiation Force Impulse (ARFI) is a noninvasive ultrasound modality that differentiates tissue structure via viscoelastic property. We are interested in using ARFI to discriminate between nonatherosclerotic arterial walls and atherosclerotic plaque. Both of these tissue types can be modeled as Kelvin materials each characterized by its own(More)
Partitioned cross-validation is proposed as a method for overcoming the large amounts of across sample variability to which ordinary cross-validation is subject. The price for cutting down on the sample noise is that a type of bias is introduced. A theory is presented for optimal trade-off of this variance and bias. Comparison with other bandwidth selection(More)
The least median of squares estimator (Rousseeuw, 1984)1 of linear regression parameters is a high breakdown estimator, meaning that, unlike the least squares estimator, it performs reasonably well when up to 50% outliers are present in a data set. Unfortunately, it lacks efficiency under normal errors. This disadvantage can be overcome by using the least(More)