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  • S C Eisenstat, H C Elman, M H Schultz, W Freund, G H Golub, N M Nachtigal +2 others
  • 2007
Overton, who showed us how the ideal Arnoldi and GMRES problems relate to more general problems of minimization of singular values of functions of matrices 17]. gmres and arnoldi as matrix approximation problems 9 least n + 1 equal maximal singular values. This follows from the fact that the degree n Chebyshev polynomial for a set in the complex plane(More)
Two neuroimaging studies using functional magnetic resonance imaging (fMRI) and thermally induced pain are presented. Fifteen healthy right-handed subjects were imaged while they had to discern different levels of thermal stimuli in the first study and while they disengaged from the feeling of pain during constant stimulation in the second study. In the(More)
BACKGROUND AND PURPOSE Stroke MRI protocols provide useful information about underlying vessel pathologies in the anterior circulation by means of intracranial time-of-flight angiography. However, these protocols mostly fail in the posterior circulation to differentiate between congenital variants and secondary thrombosis. Therefore, a high-resolution(More)
INTRODUCTION Extracranial MR neurography has so far mainly been used with 2D datasets. We investigated the use of 3D datasets for peripheral neurography of the sciatic nerve. METHODS A total of 40 thighs (20 healthy volunteers) were examined with a coronally oriented magnetization-prepared rapid acquisition gradient echo sequence with isotropic voxels of(More)
OBJECTIVES Although the etiology of complex regional pain syndrome type 1 (CRPS 1) is still debated, many arguments favor central maladaptive changes in pain processing as an important causative factor. METHODS To look for the suspected alterations, 10 patients with CRPS affecting the left hand were explored with functional magnetic resonance imaging(More)
Two neuroimaging studies using fMRI were conducted in order to assess the cortical processes involved in the perception and suppression of pain. In the first study, 15 healthy subjects were stimulated with variable intensities of electrical pulses during a discrimination task. In the second study, the same subjects had to try to suppress the feeling of pain(More)
OBJECTIVE Complex regional pain syndrome I (CRPS I) is a frequent and debilitating condition with unclear etiology. Hypothesizing that maladaptive central processes play a crucial role in CRPS, the current study set out to explore cerebral activation during a task to suppress the feeling of pain under constant painful stimulation. METHODS Ten individuals(More)
In this paper we describe a fuzzy logic based approach for providing biologically based motivations to be used in evolutionary mobile robot learning. Takagi-Sugeno-Kang (TSK) fuzzy logic is used to motivate a small mobile robot to acquire complex behaviors and to perform environment recognition. This method is implemented and tested in behavior based(More)
Transient global amnesia (TGA) is a clinical syndrome of unknown etiology characterized by sudden onset anterograde amnesia, which was thought to resolve completely. However, some authors have also suggested permanent memory impairment. It is unclear whether these results reflect a true persistent damage or a simply too short assessment interval in the(More)
BACKGROUND The TransEurope FootRace 2009 (TEFR09) was one of the longest transcontinental ultramarathons with an extreme endurance physical load of running nearly 4,500 km in 64 days. The aim of this study was to assess the wide spectrum of adaptive responses in humans regarding the different tissues, organs and functional systems being exposed to such(More)