| A critical component of spline smoothing is the choice of knots, especially for curves with varying shapes and frequencies in its domain. We consider a two-stage knot selection scheme for adaptively tting splines to data subject to noise. A potential set of knots is chosen based on information from certain wavelet decompositions with the intention to place more points where the curve shows ra...

Verrall (1996) and England & Verrall (2001) considered the use of smoothing methods in the context of claims reserving, by applying two smoothing procedures in a likelihood-based way, namely the locally weighted regression smoother (‘loess’) and the cubic smoothing spline smoother. Using the statistical methodology of semiparametric regression and its connection with mixed models (see e.g. Rupp...

We present a statistical, colour-based technique for lip tracking intended to support personal veri cation. The lips are automatically localised in the original image by exploiting grey-level gradient projections as well as chromaticity models to nd the mouth area in an automatically segmented region corresponding to the face area. A B-spline, initially with an elliptic shape is then generated ...

Smoothing Spline ANOVA is a statistical modeling algorithm based on a function decomposition similar to the classical analysis of variance (ANOVA) decomposition and the associated notions of main effect and interaction. It represents a suitable screening technique for detecting important variables (Variable Screening) in a given dataset. We present the mathematical background together with poss...

R. Mutihac Electricity and Biophysics, University of Bucharest, Bucharest, Romania Objective Analysis of an fMRI block-based visual stimulation paradigm was comparatively performed by wavelet analysis and statistical parametric mapping (SPM) [1] based on Gaussian Random Field Theory (RFT). The voxels were isotropic and the same general linear model (GLM) was employed in both SPM and the discret...

OBJECTIVE The objective of this article is to illustrate the statistical technique of spline regression, an under-utilized tool in clinical research. Spline regression was used to assess the dose-response association between serum albumin and hospital mortality. METHODS Data from a previous study of patients hospitalized throughout Florida, United States of America (U.S.A.), for invasive grou...

The penalized spline is a popular method for function estimation when the assumption of “smoothness” is valid. In this paper, methods for estimation and inference are proposed using penalized splines under the additional constraints of shape, such as monotonicity or convexity. The constrained penalized spline estimator is shown to have the same convergence rates as the corresponding unconstrain...

We present an approach for polarimetric Synthetic Aperture Radar (SAR) image region boundary detection based on the use of B-Spline active contours and a new model for polarimetric SAR data: the GH P distribution. In order to detect the boundary of a region, initial BSpline curves are specified, either automatically or manually, and the proposed algorithm uses a deformable contours technique to...