The displacement calculation from a pair of images, is a problem without a robust and complete solution. This is due to the several factors that are involved. Particularly in displacement estimation of micro-metric objects on micro-photography, is complicated by dimensions and scales involved. Usually, the process to estimate the displacement comprehends two things: (a) reference zones and simi...

The purpose of this study was to determine the reliability and validity of the GymAware optical encoder (Kinetic, Canberra, ACT) to measure displacement data (distance, peak velocity, mean velocity and time). Three GymAware sensors were attached to a Calibration Rig (CalRIG), a novel piece of technology engineered specifically for accurate calibration of dynamometry equipment. The CalRIG was pr...

This article considers a mixed finite element method for linear elasticity. It is based on a modified mixed formulation that enforces the continuity of the stress weakly by adding a jump term of the approximated stress on interior edges. The symmetric stress are approximated by nonconforming linear elements and the displacement by piecewise constants. We establish (h) error bound in the (broken...

BACKGROUND Image-guidance systems allow accurate interfractional repositioning of IMRT treatments, however, these may require up to 15 minutes. Therefore intrafraction motion might have an impact on treatment precision. 3D geometric data regarding intrafraction prostate motion are rare; we therefore assessed its magnitude with pre- and post-treatment fiducial-based imaging with cone-beam-CT (CB...

1. If an eccentric, stationary target is flashed while a subject is performing an eye movement in the dark, can this subject make a saccade to the location in space where the target briefly appeared? Different predictions result from alternative hypotheses regarding the manner in which saccade goals are determined. Retinal error being defined as the vector from the eye position at the time of t...

In this paper we do a systematic investigation of continuous methods for pixel, line pixel and line dejittering. The basis for these investigations are the discrete line dejittering algorithm of Nikolova and the partial differential equation of Lenzen et al for pixel dejittering. To put these two different worlds in perspective we find infinite dimensional optimization algorithms linking to the...

Cross-correlation constitutes the state-of-the-art method for measuring motion in PIV data. We present a novel variational approach to correlation-based fluid flow estimation, which determines the displacements via continuous optimisation. A Gaussian shaped window function is used, whose size, eccentricity and orientation can freely be chosen. We adapt the shape to the noise level and displacem...

In the Fröhlich illusion, the first position of a moving target is mis-localized in the direction of motion. In the onset repulsion effect, the opposite error occurs. To reconcile these conflicting error patterns, we improved previous methods by using natural pointing movements and a large range of target velocities. Displacement was found to increase in the direction of motion, but the linear ...