Stefan Popescu

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Digital flat-panel-based volume CT (VCT) represents a unique design capable of ultra-high spatial resolution, direct volumetric imaging, and dynamic CT scanning. This innovation, when fully developed, has the promise of opening a unique window on human anatomy and physiology. For example, the volumetric coverage offered by this technology enables us to(More)
Zusammenfassung. Da es sich bei IT-Services um immaterielle Produkte von IT-Betreibern handelt, basieren SLA-Verhandlungen zwischen Dienstleistern und Dienstnehmern auf IT-Service-Beschreibungen. Derartige Beschreibungen müssen als Kriterien erfüllen, dass die Funktionalitäten und Qualitäten der angebotenen IT-Services mit den verfügbaren Ressourcen des(More)
In this paper, we consider the computational power of a new variant of networks of evolutionary processors which seems to be more suitable for a software and hardware implementation. Each processor as well as the data navigating throughout the network are now considered to be polarized. While the polarization of every processor is predefined, the data(More)
OBJECTIVES X-ray computed tomography (CT) using phase contrast can provide images with greatly enhanced soft-tissue contrast in comparison to conventional attenuation-based CT. We report on the first scan of a human specimen recorded with a phase-contrast CT system based on an x-ray grating interferometer and a conventional x-ray tube source. Feasibility(More)
In this presentation, the record results of a directly modulated PLANEX external cavity lasers (ECL), which has achieved 80 km transmission distances at 10 Gbps with a power penalty of only 1.4 dB, due to optimized chirp characteristics are presented. The ECL has been miniaturized and integrated into a TOSA applicable for industry standard XFP modules, and(More)
After having shown that the corresponding components of a four vector transform via the same transformation factors as the space-time coordinates of the same event do, we design a relativistic diagram that displays in true values theirs components. One diagram works for events generated by tardyons whereas a second diagram works for events generated by(More)
Phase-contrast imaging at laboratory-based x-ray sources using grating interferometers has been developed over the last few years for x-ray energies of up to 28 keV. Here, we show first phase-contrast projection and tomographic images recorded at significantly higher x-ray energies, produced by an x-ray tube source operated at 100 kV acceleration voltage.(More)