Maxwell's equations imply that imaging gradients are accompanied by higher order spatially varying fields (concomitant fields) that can cause artifacts in MR imaging. The lowest order concomitant fields depend quadratically on the imaging gradient amplitude and inversely on the static field strength. Time-varying concomitant fields that accompany the readout gradients of spiral scans cause unwa...

The secrecy capacity problems over the general arbitrarily varying wiretap channel, with respect to the maximal decoding error probability and strong secrecy criterion, are considered, where the channel state sequence may be known or unknown at the receiver. In the mean time, it is always assumed that the channel state sequence is known at the eavesdropper and unknown at the transmitter. Capaci...

The problem of predicting the next outcome of an individual binary sequence, based on past observations which are corrupted by arbitrarily varying memoryless additive noise, is considered. The goal of the predictor is'to perform, for each individual sequence, "almost" as well as the best in a set of experts, where performance is evaluated using a general loss function. This setting is a general...

Communication over channels that may vary in an arbitrary and unknown manner from channel use to channel use is studied. Such channels fall in the framework of arbitrarily varying channels (AVCs), for which it has been shown that the classical deterministic approaches with pre-specified encoder and decoder fail if the AVC is symmetrizable. However, more sophisticated strategies such as common r...

An available bit rate (ABR) service allows applications to access a time-varying network capacity. In a basic ABR service, the available network capacity is divided \fairly" amongst active connections, without regard to the utility that each application derives from the bandwidth allocation. The goal of this paper is to improve both the global and individual utility obtained by applications usi...

Introduction. Because of its proposed potential to better localize neuronal activity and to observe activation through a mechanism different from the BOLD effect, diffusion-weighted fMRI (DFMRI) has drawn much attention [1-5]. Data from studies using lower b-values indicate an increase of the apparent water diffusion coefficient (ADC) during functional activation, which is thought to be caused ...