Computing displacement from measured acceleration is important for understanding the characteristics of an earthquake. However, to obtain such displacement with a good accuracy is difficult. It is partly because the low-frequency component dominating the behavior of the displacement is often affected by the sensor’s tilt and the measurement error. To avoid these, a high pass filter is usually a...

An important application of deformable motion estimation theory is the estimation of heart motion from tagged MR image sequences. In MR tagged images, the heart appears with a spatially encoded pattern that moves with the tissue. The position of the tag pattern in each frame of the image sequence can be used to obtain sparse measurements of the heart's 3D displacement eld. In this paper, we pro...

background: radial movement of the arterial wall is a well-known indicator of the mechanical properties of arteries in arterial disease examinations. in the present study, two different motion estimation methods, based on the block-matching and maximum-gradient algorithms, were examined to extract the radial displacement of the carotid artery wall. methods: each program was separately implement...

Metrology applications commonly require non-contact, capacitive sensors for displacement measurements due to their nanometer resolution. In some metrology applications, for example, the measurement of roundness and spindle error motion, the displacements of stationary and rotating cylindrical artifacts are measured. Error from using a conventionally calibrated sensor with a non-flat (e.g., cyli...

Chloride-induced corrosion is a key factor in the premature corrosion of concrete structures exposed to a marine environment. Fick's second law of diffusion is the dominant equation to model diffusion of chloride ions. This equation is traditionally solved by Finite Element Method (FEM) and Finite Difference Method (FDM). Although these methods are robust and efficient, they may face some numer...

In this paper, the Lamé coefficients in the linear elasticity problem are estimated by using the measurements of displacement. Some a posteriori error estimators for the approximation error of the parameters are derived, and then adaptive finite element schemes are developed for the discretization of the parameter estimation problem, based on the error estimators. The GaussNewton method is empl...

A new technique for estimating interframe displacement of small blocks with minimum mean square error is presented. An efficient algorithm for searching the direction of displacement has been described. The results of applying the technique to two sets of images are presented which show 8-10 dB improvement in interframe variance reduction due to motion compensation. The motion compensation is a...

A common source of error in particle tracking experiments is identified, and a theoretical model for the magnitude of the error is offered. In many cases, the error is small, but in systems where only a few particles are being tracked, the measured mean squared displacement can be up to 50% smaller than the actual value. The theoretical model predictions are confirmed using numerical simulation...

We study the dual mixed finite element approximation of unilateral contact problems. Based on the dual mixed variational formulation with three unknowns (stress, displacement and the displacement on the contact boundary), the a priori error estimates have been established for both conforming and nonconforming finite element approximations. A Uzawa type iterative algorithm is developed to solve ...