Many time-series smoothing methods can be used for reducing noise and extracting plant phenological parameters from remotely-sensed data, but there is still no conclusive evidence in favor of one method over others. Here we use moderate-resolution imaging spectroradiometer (MODIS) derived normalized difference vegetation index (NDVI) to investigate five smoothing methods: Savitzky-Golay fitting...

Recently [1], a H∞ smoother has been developed and it gives good results for noise uncertainties. Nevertheless, when appear uncertain parameters, its performances decrease significantly. That’s why, in this paper, an estimator robust to noise uncertain properties and parameter uncertainties is presented. As in [1, 4, 6], the robust H∞ smoother for uncertain systems is developed as a combination...

IMPORTANCE Postoperative hospital-acquired infections (HAIs) may result from disruption of natural barrier sites. Recent studies have linked vitamin D status and barrier site integrity. OBJECTIVE To investigate the association between preoperative vitamin D status and the risk for HAIs. DESIGN, SETTING, AND PARTICIPANTS A retrospective analysis was performed using propensity score methods t...

BACKGROUND Despite widespread use of 12-step treatment approaches and referrals to Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) by youth providers, little is known about the significance of these organizations in youth addiction recovery. Furthermore, existing evidence is based mostly on short-term follow-up and is limited methodologically. METHODS Adolescent inpatients (n = 160; me...

When using cDNA microarrays, normalization to correct labeling bias is a common preliminary step before further data analysis is applied, its objective being to reduce the variation between arrays. To date, assessment of the effectiveness of normalization has mainly been confined to the ability to detect differentially expressed genes. Since a major use of microarrays is the expression-based ph...

In [TSP], level curves of a function , called “the edge strength function,” defined for 2–dimensional shapes, are interpreted as successively smoother versions of the initial shape boundary. The local minima of the absolute gradient along the level curves of are shown to be a robust criterion for determining the shape skeleton. More generally, at an extremal point of along a level curve, the le...

We propose two nonlinear Kalman smoothers that rely on Student’s t distributions. The T-Robust smoother finds the maximum a posteriori likelihood (MAP) solution for Gaussian process noise and Student’s t observation noise, and is extremely robust against outliers, outperforming the recently proposed `1-Laplace smoother in extreme situations (e.g. 50% or more outliers). The second estimator, whi...

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...

Geographically Weighted Regression (GWR) is a method of spatial analysis that can be used to perform by assigning weights based on the geographical distance each observation location and assumption having heterogeneity. The result this an equation model whose parameter values apply only are different from other locations. However, when there outliers at location, more robust estimation needed. ...