@phdthesis{Stamm2010,
  author    = {Stamm, Heimo Helmut},
  title     = {Parallele Echtzeitbildgebung zur Quantifizierung der linksventrikul{\"a}ren Herzfunktion bei freier Atmung mittels MRT},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47900},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {MRT-Untersuchungen des Herzens haben in den letzten Jahren an H{\"a}ufigkeit und Bedeutung zugenommen. Die Nachfrage nach schnelleren und f{\"u}r den Patienten komfortableren Sequenzen steigt. Diese Arbeit untersucht, ob es mit Hilfe von parallelen Echtzeitsequenzen ohne EKG-Triggerung m{\"o}glich ist, die Untersuchungszeit deutlich zu verk{\"u}rzen und dabei gut reproduzierbare Messwerte zu erhalten. Hierzu wurden 9 Probanden und 21 Patienten mit A) paralleler Echtzeitbildgebung bei freier Atmung und B)einer Standard CINE Sequenz mit Atemstopp untersucht. Zur statistischen Analyse beider Methoden dienten Bland-Altman-Plots. Um Aussagen {\"u}ber die Reproduzierbarkeit der Ergebnisse treffen zu k{\"o}nnen wurde außerdem die Variabilit{\"a}t der Messungen bestimmt. Die Messzeit der neuen Echtzeitsequenz war um mehr als das zehnfache k{\"u}rzer als die einer herk{\"o}mmlichen CINE Sequenz. Die Ergebnisse waren mit der Standard CINE Sequenz vergleichbar und zeigten nur einen geringe Variabilit{\"a}t. Lediglich die linksventrikul{\"a}re Masse wurde im Gesamtkollektiv leicht {\"u}bersch{\"a}tzt. Insgesamt scheint die Echtzeitbildgebung aufgrund der zuverl{\"a}ssigen Ergebnisse f{\"u}r den Klinikalltag geeignet. Insbesondere Patienten mit Atemnot, Herzrhythmusst{\"o}rungen oder aber Kinder k{\"o}nnten profitieren.},
  subject      = {MRT},
  language  = {de}
}
@phdthesis{Portmann2023,
  author    = {Portmann, Johannes},
  title     = {Accelerated inversion recovery MRI of the myocardium using spiral acquisition},
  doi       = {10.25972/OPUS-30282},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302822},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {This work deals with the acceleration of cardiovascular MRI for the assessment of functional information in steady-state contrast and for viability assessment during the inversion recovery of the magnetization. Two approaches are introduced and discussed in detail. MOCO-MAP uses an exponential model to recover dynamic image data, IR-CRISPI, with its low-rank plus sparse reconstruction, is related to compressed sensing. MOCO-MAP is a successor to model-based acceleration of parametermapping (MAP) for the application in the myocardial region. To this end, it was augmented with a motion correction (MOCO) step to allow exponential fitting the signal of a still object in temporal direction. Iteratively, this introduction of prior physical knowledge together with the enforcement of consistency with the measured data can be used to reconstruct an image series from distinctly shorter sampling time than the standard exam (< 3 s opposed to about 10 s). Results show feasibility of the method as well as detectability of delayed enhancement in the myocardium, but also significant discrepancies when imaging cardiac function and artifacts caused already by minor inaccuracy of the motion correction. IR-CRISPI was developed from CRISPI, which is a real-time protocol specifically designed for functional evaluation of image data in steady-state contrast. With a reconstruction based on the separate calculation of low-rank and sparse part, it employs a softer constraint than the strict exponential model, which was possible due to sufficient temporal sampling density via spiral acquisition. The low-rank plus sparse reconstruction is fit for the use on dynamic and on inversion recovery data. Thus, motion correction is rendered unnecessary with it. IR-CRISPI was equipped with noise suppression via spatial wavelet filtering. A study comprising 10 patients with cardiac disease show medical applicability. A comparison with performed traditional reference exams offer insight into diagnostic benefits. Especially regarding patients with difficulty to hold their breath, the real-time manner of the IR-CRISPI acquisition provides a valuable alternative and an increase in robustness. In conclusion, especially with IR-CRISPI in free breathing, a major acceleration of the cardiovascular MR exam could be realized. In an acquisition of less than 100 s, it not only includes the information of two traditional protocols (cine and LGE), which take up more than 9.6 min, but also allows adjustment of TI in retrospect and yields lower artifact level with similar image quality.},
  subject      = {Kernspintomografie},
  language  = {en}
}
@techreport{GrigorjewMetzgerHossfeldetal.2020,
  author    = {Grigorjew, Alexej and Metzger, Florian and Hoßfeld, Tobias and Specht, Johannes and G{\"o}tz, Franz-Josef and Schmitt, J{\"u}rgen and Chen, Feng},
  title     = {Technical Report on Bridge-Local Guaranteed Latency with Strict Priority Scheduling},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-198310},
  year      = {2020},
  abstract  = {Bridge-local latency computation is often regarded with caution, as historic efforts with the Credit-Based Shaper (CBS) showed that CBS requires network wide information for tight bounds. Recently, new shaping mechanisms and timed gates were applied to achieve such guarantees nonetheless, but they require support for these new mechanisms in the forwarding devices. This document presents a per-hop latency bound for individual streams in a class-based network that applies the IEEE 802.1Q strict priority transmission selection algorithm. It is based on self-pacing talkers and uses the accumulated latency fields during the reservation process to provide upper bounds with bridge-local information. The presented delay bound is proven mathematically and then evaluated with respect to its accuracy. It indicates the required information that must be provided for admission control, e.g., implemented by a resource reservation protocol such as IEEE 802.1Qdd. Further, it hints at potential improvements regarding new mechanisms and higher accuracy given more information.},
  subject      = {Echtzeit},
  language  = {en}
}
@techreport{GrigorjewMetzgerHossfeldetal.2020,
  author    = {Grigorjew, Alexej and Metzger, Florian and Hoßfeld, Tobias and Specht, Johannes and G{\"o}tz, Franz-Josef and Chen, Feng and Schmitt, J{\"u}rgen},
  title     = {Asynchronous Traffic Shaping with Jitter Control},
  doi       = {10.25972/OPUS-20582},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-205824},
  pages     = {8},
  year      = {2020},
  abstract  = {Asynchronous Traffic Shaping enabled bounded latency with low complexity for time sensitive networking without the need for time synchronization. However, its main focus is the guaranteed maximum delay. Jitter-sensitive applications may still be forced towards synchronization. This work proposes traffic damping to reduce end-to-end delay jitter. It discusses its application and shows that both the prerequisites and the guaranteed delay of traffic damping and ATS are very similar. Finally, it presents a brief evaluation of delay jitter in an example topology by means of a simulation and worst case estimation.},
  subject      = {Echtzeit},
  language  = {en}
}