On the approximate controllability of the stochastic Maxwell equations

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ON THE RECONSTRUCTION OF A SMALL ELASTIC SPHERE IN THE NEAR FIELD BY POINT-SOURCES

A near-field reconstruction method which locates the radius and the position of a small elastic rigid sphere in the low frequency sense is considered. In particular, the direct scattering problem for a rigid sphere by a point generated dyadic field is presented in a dyadic form, and the exact Green’s function as well as the elastic far field patterns of the radiating solution in form of infinite series are obtained. Finally, the inversion scheme is based on a closed form approximation of the scattered field at the source for various point-source locations

A TIME DOMAIN ANALYSIS FOR CHIRAL DETERMINISTIC AND RANDOM MEDIA IN ELECTROMAGNETICS

In this work we present some results on deterministic and stochastic models for chiral media in the time domain. We examine mild, strong and classical well posedness for the Cauchy problem of the integrodifferential equation that arises from Maxwell’s equations under the full constitutive relations for chiral media. A stochastic model with multiplicative noise for this Cauchy problem is studied and mild and strong well posedness results are established. Further, we examine the well posedness for a widely used, local in time, approximation of the full constitutive relations, namely the DBF model

The effect of a combined tube current modulation system on dose delivered to patients undergoing thoracic and abdominal CT with a 128-slice scanner

Combined tube current modulation techniques (such as Care Dose4D used in this study) during computed tomography (CT) procedures bring together the benefits of the angular and z-axis modulation techniques, measuring X-ray attenuation profile in the z-axis together with the data from the perpendicular x-y direction with a sophisticated algorithm. The purpose of this study was to investigate the radiation dose, in terms of computed tomography dose index (CTDIvol), delivered to patients during thoracic and abdominal CT using this technique and compare it with the corresponding CTDIvol of the fixed tube current CT technique. The results revealed a 5-32% dose reduction for chest CT and a dose reduction of 7.6-60% for the three-sequence abdominal CT scan of normal and overweight patients. In the case of obese patients a 15.4-18.7% dose increase for chest CT and a (21.5) 2 (26.3)% dose increase for the three-stage abdominal examinations for females and males, respectively, was revealed. © The Author 2012. Published by Oxford University Press. All rights reserved