TY - CHAP A1 - Harzheim, Thomas A1 - Heuermann, Holger T1 - Phase Repeatable Synthesizers as a New Harmonic Phase Standard for Nonlinear Network Analysis T2 - IEEE Transactions on Microwave Theory and Techniques Y1 - 2018 U6 - https://doi.org/10.1109/TMTT.2018.2817513 SP - 1 EP - 8 PB - IEEE ER - TY - JOUR A1 - Ritz, Thomas T1 - Personalized Information Services: Production and Distribution of these Services employing Mass-Customization Y1 - 2002 N1 - International Congress on Mass Media and Communications in the e-society of the 21st Century, Moskau, 17.-19.10.2002 ER - TY - JOUR A1 - Ritz, Thomas T1 - Personalized information services : an electronic information commodity and its production JF - International Journal of E-Business Strategy Management Y1 - 2000 SN - 1467-0305 VL - 2 IS - 2 ER - TY - CHAP A1 - Ritz, Thomas T1 - Personalized information services : an electronic information commodity and its production T2 - Electronic publishing '01 : 2001 in the digital publishing odyssey ; proceedings of an ICCC/IFIP conference held at the University of Kent at Canterbury, Kent, United Kingdom, 5 - 7 July, 2001 ; [proceedings of the Fifth Conference on Electronic Publishing] Y1 - 2001 SN - 1-58603-191-0 SP - 48 EP - 58 PB - IOS Press [u.a.] CY - Amsterdam ER - TY - JOUR A1 - Schuba, Marko A1 - Hermanns, Oliver T1 - Performance Investigations of the IP Multicast Architecture / Hermanns, Oliver ; Schuba, Marko JF - Performance of the IP Multicast Achitecture . Proceedings JENC 6. Proceedings of the 6th Joint European Networking Conference, Tel Aviv Y1 - 1995 N1 - Reprinted in Computer Networks and ISDN Systems 28 pp 429-439, 1996 SP - 121-1 EP - 121-8 ER - TY - JOUR A1 - Schuba, Marko A1 - Haverkort, Boudewijn R. A1 - Schneider, Gaby T1 - Performance evaluation of multicast communication in packet-switched networks / Schuba, Marko ; Haverkort, Boudewijn R. ; Schneider, Gaby JF - Performance Evaluation. 39 (2000), H. 1-4 Y1 - 2000 SN - 0166-5316 N1 - http://dx.doi.org/10.1016/S0166-5316(99)00058-9 SP - 61 EP - 80 ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Orzada, Stephan A1 - Flöser, Martina A1 - Rietsch, Stefan H. G. A1 - Schmidt, Simon A1 - Stelter, Jonathan K. A1 - Wittrich, Marco A1 - Quick, Harald H. A1 - Bitz, Andreas A1 - Ladd, Mark E. T1 - Performance and safety assessment of an integrated transmit array for body imaging at 7 T under consideration of specificabsorption rate, tissue temperature, and thermal dose JF - NMR in Biomedicine N2 - In this study, the performance of an integrated body-imaging array for 7 T with 32 radiofrequency (RF) channels under consideration of local specific absorption rate (SAR), tissue temperature, and thermal dose limits was evaluated and the imaging performance was compared with a clinical 3 T body coil. Thirty-two transmit elements were placed in three rings between the bore liner and RF shield of the gradient coil. Slice-selective RF pulse optimizations for B1 shimming and spokes were performed for differently oriented slices in the body under consideration of realistic constraints for power and local SAR. To improve the B1+ homogeneity, safety assessments based on temperature and thermal dose were performed to possibly allow for higher input power for the pulse optimization than permissible with SAR limits. The results showed that using two spokes, the 7 T array outperformed the 3 T birdcage in all the considered regions of interest. However, a significantly higher SAR or lower duty cycle at 7 T is necessary in some cases to achieve similar B1+ homogeneity as at 3 T. The homogeneity in up to 50 cm-long coronal slices can particularly benefit from the high RF shim performance provided by the 32 RF channels. The thermal dose approach increases the allowable input power and the corresponding local SAR, in one example up to 100 W/kg, without limiting the exposure time necessary for an MR examination. In conclusion, the integrated antenna array at 7 T enables a clinical workflow for body imaging and comparable imaging performance to a conventional 3 T clinical body coil. KW - body imaging at 7 T MRI KW - thermal dose KW - tissue temperature KW - transmit antenna arrays Y1 - 2022 U6 - https://doi.org/10.1002/nbm.4656 SN - 0952-3480 (Print) SN - 1099-1492 (Online) VL - 35 IS - 5 SP - 1 EP - 17 PB - Wiley ER - TY - JOUR A1 - Schuba, Marko T1 - Performance Analysis of Reliable Multicast Mechanisms for Widely Spread Distributed Applications in the Internet JF - International Conference on Parallel and Distributed Processing Techniques and Applications : PDPTA '99 ; June 28 - July 1, 1999, Las Vegas, Nevada, USA / ed.: Hamid R. Arabnia Y1 - 1999 SN - 1892512157 SP - 1 EP - 7 ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Orzada, Stephan A1 - Flöser, Martina A1 - Rietsch, Stefan H. G. A1 - Quick, Harald H. A1 - Ladd, Mark E. A1 - Bitz, Andreas T1 - Performance analysis of integrated RF microstrip transmit antenna arrays with high channel count for body imaging at 7 T JF - NMR in Biomedicine N2 - The aim of the current study was to investigate the performance of integrated RF transmit arrays with high channel count consisting of meander microstrip antennas for body imaging at 7 T and to optimize the position and number of transmit ele- ments. RF simulations using multiring antenna arrays placed behind the bore liner were performed for realistic exposure conditions for body imaging. Simulations were performed for arrays with as few as eight elements and for arrays with high channel counts of up to 48 elements. The B1+ field was evaluated regarding the degrees of freedom for RF shimming in the abdomen. Worst-case specific absorption rate (SARwc ), SAR overestimation in the matrix compression, the number of virtual obser- vation points (VOPs) and SAR efficiency were evaluated. Constrained RF shimming was performed in differently oriented regions of interest in the body, and the devia- tion from a target B1+ field was evaluated. Results show that integrated multiring arrays are able to generate homogeneous B1+ field distributions for large FOVs, espe- cially for coronal/sagittal slices, and thus enable body imaging at 7 T with a clinical workflow; however, a low duty cycle or a high SAR is required to achieve homoge- neous B1+ distributions and to exploit the full potential. In conclusion, integrated arrays allow for high element counts that have high degrees of freedom for the pulse optimization but also produce high SARwc , which reduces the SAR accuracy in the VOP compression for low-SAR protocols, leading to a potential reduction in array performance. Smaller SAR overestimations can increase SAR accuracy, but lead to a high number of VOPs, which increases the computational cost for VOP evaluation and makes online SAR monitoring or pulse optimization challenging. Arrays with interleaved rings showed the best results in the study. KW - body imaging at UHF MRI KW - integrated transmit coil arrays KW - VOP compression Y1 - 2021 U6 - https://doi.org/10.1002/nbm.4515 SN - 0952-3480 (ISSN) SN - 1099-1492 (eISSN) VL - 34 IS - 7 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Hagemann, Hans-Jürgen A1 - Geittner, P. T1 - PCVD hybrid technology for single mode fibres. Hagemann, H. J.; Geittner, P. JF - Proceedings : papers presented at: the 8th Annual European Fibre Optic Communications and Local Area Networks Exposition Y1 - 1990 N1 - EFOC LAN <8, 1990, München> SP - 67 EP - 72 ER -