Long acquisition times lead to image artifacts in thoracic C-arm CT. Motion blur caused by respiratory motion leads to decreased image quality in many clinical applications. We introduce an image-based method to estimate and compensate respiratory motion in C-arm CT based on diaphragm motion. In order to estimate respiratory motion, we track the contour of the diaphragm in the projection image ...

Introduction The heterogeneities in the crust and upper mantle structure as well as the complex source rupture process have an important influence on regional seismic wavefield, particularly for high-frequency waves. Moreover small-scale heterogeneities such as for the sedimentary basin introduce significant amplification of ground motion, which lead to long ground shaking over several minutes ...

the produced electric and magnetic fields due to lightning strikes to mountainous ground are determined in this paper. for the sake of simplicity a cone-shaped ground with finite conductivity is assumed to represent a natural nonflat ground. by this assumption, we deal with an axillary symmetrical structure so we use the cylindrical 2d-fdtd to save the simulation memory and time, dramatically. ...

Radiotherapy of lung and liver lesions has changed from normofractioned 3D-CRT to stereotactic treatment in a single or few fractions, often employing volumetric arc therapy (VMAT)-based techniques. Potential unintended interference of respiratory target motion and dynamically changing beam parameters during VMAT dose delivery motivates establishing 4D quality assurance (4D QA) procedures to as...

near-fault ground motions have caused very much damage in the vicinity of seismic sources during recent earthquakes. it is well known that under specific circumstances, intensive ground shakings near fault ruptures may be characterized by short-duration impulsive motions. this pulse-type motion is generally particular to the forward direction, where the fault rupture propagates towards the site...