We consider kernel estimators of the instantaneous frequency of a slowly evolving sinusoid in white noise. The expected estimation error consists of two terms. The systematic bias error grows as the kernel halfwidth increases while the random error decreases. For a nonmodulated signal, g(t), the kernel halfwidth which minimizes the expected error scales as h ∼ [ σ2 N |∂2 t g |2 ]1/5 , where σ2 ...

Computer-assisted video motion analysis is a method of evaluating human kinematics that offers promise both for research and for clinical application. This study determined the upper limits of accuracy and consistency of linear and angular measures obtained using the Ariel Performance Analysis System. Reference standards included a meter stick and a universal 360 degrees goniometer. Average mea...

BACKGROUND Physical activity recall instruments provide an inexpensive method of collecting physical activity patterns on a sample of individuals, but they are subject to systematic and random measurement error. Statistical models can be used to estimate measurement error in activity recalls and provide more accurate estimates of usual activity parameters for a population. METHODS We develop ...

BACKGROUND Clinical evidence continues to expand and is increasingly difficult to overview. We aimed at conceptualizing a visual assessment tool, i.e., a matrix for overviewing studies and their data in order to assess the clinical evidence at a glance. METHODS A four-step matrix was constructed using the three dimensions of systematic error, random error, and design error. Matrix step I rank...

BACKGROUND To evaluate the daily total error shift patterns on post-prostatectomy patients undergoing image guided radiotherapy (IGRT) with a diagnostic quality computer tomography (CT) on rails system. METHODS A total of 17 consecutive post-prostatectomy patients receiving adjuvant or salvage IMRT using CT-on-rails IGRT were analyzed. The prostate bed's daily total error shifts were evaluate...

background: the purpose of this work is to discover and analyze errors and incidents in some radiotherapy centers, and to introduce methods that could reduce their occurrences, especially those which had happened due to the use of improper and inadequate equipment. this work is a first step toward clarifying the role of education in a risk-conscious culture, and changing the attitude of radioth...

We discuss how the space of possible cosmological parameters is constrained by the angular diameter distance function, DA(z), as measured using the SZ/X-ray method which combines Sunyaev-Zel’dovich (SZ) effect and X-ray brightness data for clusters of galaxies. New X-ray satellites, and ground-based interferometers dedicated to SZ observations, should soon lead to DA(z) measurements limited by ...

An optimal calibration method for a microelectro-mechanical inertial measurement unit (MIMU) is presented in this paper. The accuracy of the MIMU is highly dependent on calibration to remove the deterministic errors of systematic errors, which also contain random errors. The overlapping Allan variance is applied to characterize the types of random error terms in the measurements. The calibratio...