This paper challenges the two popular approaches used in image matching: the gradient approach and the phase approach. We demonstrate from both theoretical and experimental points of view that the gradient approach has large model-incurred errors when the images contain signi cant high frequency information, and the phase approach has the same kind of errors when the images contain mainly low f...

Kinetic-transport equations are, by now, standard models to describe the dynamics of populations of bacteria moving by run-and-tumble. Experimental observations show that bacteria increase their run duration when encountering an increasing gradient of chemotactic molecules. This led to a first class of models which heuristically include tumbling frequencies depending on the path-wise gradient o...

It is attractive to consider an approach similar to the ballistocadiogram suppression in removal of the gradient artifacts. However, small timing shifts of the digital sampling with respect to the gradient activity will result in incomplete removal of the artifact. With a sampling frequency fs and an artifact frequency (e.g., due to gradients) of f0, sampling errors of = 2πf0/fs are to be expec...

We propose two low complexity adaptive step-size mechanisms based on the normalised orthogonal gradient algorithm for frequency-domain equalisation in orthogonal frequency division multiplexing (OFDM) systems. These algorithms are derived from employing a mixed-subcarrier exponentially weighted least squares criterion. Two low complexity adaptive stepsize approaches are investigated by exploiti...

For gradient descent learning to yield connectivity consistent with real biological networks, the simulated neurons would have to include more realistic intrinsic properties such as frequency adaptation. However, gradient descent learning cannot be used straightforwardly with adapting rate-model neurons because the derivative of the activation function depends on the activation history. The obj...

Boddy, Geoffrey, and E. E. Daniel. Role of L-Ca channels in intestinal pacing in wild-type and W/W mice. Am J Physiol Gastrointest Liver Physiol 288: G439–G446, 2005. First published October 14, 2004; doi:10.1152/ajpgi.00255.2004.—Rhythmic contractions generating transit in the digestive tract are paced by a network of cells called interstitial cells of Cajal (ICC) found in the myenteric plexus...

Background and Methods: Guided by both spring and string ideas [1-3], we have previously investigated the manner in which sets of vibrational frequencies can be canceled by the appropriately designed gradient pulse. A picture of the cancellation of vibrations produced with a Lorentz impulsive force by an “anti-impulsive” follow-up force has emerged. This also provided a physical understanding o...

A study of a non-uniform metamaterial array consisting of six split-ring resonators of varying diameters is conducted experimentally to measure the transmission and reflection characteristics that arise from asymmetry in the longitudinal direction. Such characteristics are examined and compared with their counterpart symmetric scattering coefficients associated with a uniform split-ring array....

This paper evaluates a new, low-frequency finite-difference time-domain method applied to the problem of induced E-fields/eddy currents in the human body resulting from the pulsed magnetic field gradients in MRI. In this algorithm, a distributed equivalent magnetic current is proposed as the electromagnetic source and is obtained by quasistatic calculation of the empty coil's vector potential o...

The modulation of spin phase produced by Carr-Purcell-Meiboom-Gill (CPMG) sequence in combination with constant magnetic field gradient is appropriate to probe the displacement power spectrum (DPS). The spin-echo attenuation is directly proportional to the DPS value at the applied modulation frequency. Relaxation and selective excitation effects can be factored out while probing the DPS. The mo...