BACKGROUND AND PURPOSE Computerized 3-dimensional (3-D) motion measurement systems are used by those interested in human motion. The purposes of this study were (1) to determine the limits of accuracy in determining intersegmental angles during pendular motion at varying speeds and (2) to determine changes in accuracy introduced by autodigitization and digitization by experienced manual raters....

Simultaneous estimates of cardiac output were made during graded upright maximal exercise in 10 male subjects by means of Doppler velocity spectrum of ascending aortic flow, apical two-dimensional echocardiograms, thermodilution, and Fick oximetry. In 15 subjects, aortic annular and root diameters were measured during similar exercise from parasternal two-dimensional echocardiograms. The linear...

The aim of this paper is to consider the optimal, from the viewpoint of a state estimation accuracy, measurement location problem in linear distributed-parameter systems with white Gaussian noises. In contrary to earlier works the proposed approach consists of two steps. Namely, to find closed form solution for the optimal measurement weighting function (MWF), assuming measurements continuous i...

BACKGROUND Although a number of methods are used to estimate polyethylene liner wear from radiographs of total hip replacements, there is no consensus with regard to the accuracy of these methods. The purpose of this study was to compare the accuracy of several such measurement methods with use of both laboratory radiographs and routine clinical radiographs. METHODS A phantom apparatus was de...

The beam hardening effect is one of the major artifacts of X-ray computed tomography. It not only complicates medical inspection and material analysis, but also influences the accuracy and repeatability of dimensional measurements. Therefore, many efforts have been devoted to develop beam hardening correction methods since the early 1970s. In practice, the combination of hardware filters (pre-f...

We present an analysis of the accuracy and information content of three-dimensional reconstructions of the dielectric susceptibility of a sample from noisy, near-field holographic measurements, such as those made in scanning probe microscopy. Holographic measurements are related to the dielectric susceptibility via a linear operator within the accuracy of the first Born approximation. The maxim...

Many applications in vehicular communications require the collection of vehicular position traces. So far this has been done by recording and transmitting unencoded position samples. Depending on the frequency and resolution of these samples, the resulting data may be very large, consuming significant resources for storage and transmission. In this paper, we propose a method based on two-dimens...

The robust three-dimensional position architecture is proposed in the paper, where the hybrid time difference of arrival (TDOA) and direction of arrival (DOA) position system was designed to backup the four-station TDOA position system. The digital time delay estimation (TDE) receiver is used for TDOA measurement and the cylindrical array antenna is used for DOA measurement. The general formula...