PURPOSE To optimize a T1-weighted fast fluid-attenuated inversion recovery (FLAIR) sequence using computer-simulated data and to study its clinical utility for imaging the spine. METHODS Relative signal intensities and contrast of relevant normal and pathologic tissues in the spine were computed using an inversion recovery equation modified to account for a hybrid RARE (rapid acquisition with...

It has been repeatedly shown that face inversion affects the recognition of emotional faces. However, previous results are heterogeneous concerning the affected emotions and the influence of presentation time is unclear. We examined the impact of limited presentation time (200 ms) on the face-inversion effect during recognition of basic emotions in 128 healthy young adults. Data analysis reveal...

Inversion of local-area helioseismic time-distance data has so far only been done in the ray approximation (Kosovichev 1996). Since this is a high-frequency approximation its applicability can be questioned for the solar case. Bogdan (1997) showed that for a simple solar model the localized wave packets do follow, but are not connned to, the ray path. We use an approximation based on the rst Fr...

The distribution of the lengths of genomic segments inverted during the evolutionary divergence of two species cannot be inferred directly from the output of genome rearrangement algorithms, due to the rapid loss of signal from all but the shortest inversions. The number of short inversions produced by these algorithms, however, particularly those involving a single gene, is relatively reliable...

The left-inverse system with minimal order of a discrete-time nonlinear system is studied in a linear algebraic framework. The general structure of the left inverse is described. Two algorithms are given for constructing left-inverse systems having minimal order.

In this work, we propose neural network inversion of a backward predictor as a technique for multi-step prediction of dynamic time series. It may be di cult to train a large network to capture the correlation that exists in some dynamic time series represented by small data sets. The new approach combines an estimate obtained from a forward predictor with an estimate obtained by inverting a bac...

OBJECTIVE To compare the effects of tape, with and without prewrap, on dynamic ankle inversion before and after exercise. DESIGN AND SETTING Doubly multivariate analyses of variance were used to compare the taping and exercise conditions. Subjects were randomly assigned to a fixed treatment order as determined by a balanced latin square. The independent variables were tape application (no tap...

We present two new techniques for the inversion of first-arrival times to estimate velocity structure. These travel-time inversion techniques are unique in that they do not require the calculation of ray paths. First-arrival times are calculated using a finite-difference scheme that iteratively solves the eikonal equations for the position of the wavefront. The first inversion technique is a di...

The word tomography finds its origins in the two Greek words tomos, meaning section, and graphy, which translates as drawing. There are many different types of tomography used in many sciences such as medicine, biology, materials science and geology. The basic idea of tomography in all of its uses is to obtain a cross-section of an object which will then be used to infer various facts regarding...