TY - JOUR A1 - Heuermann, Holger A1 - Baumann, F.-M. A1 - Fauth, G. A1 - Albert, M. T1 - Results of Network Analyzer Measurements with Leakage Errors Corrected with the TMS-15-Term Procedure JF - On-Line Moisture Analysis of Raw Coal Y1 - 1994 N1 - 1993 International Symposium on On-Line Analysis of Coal : Vienna ; [proceedings]. SP - 1361 EP - 1364 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, B. T1 - Results of network analyzer measurements with leakage errors-corrected with direct calibration techniques JF - IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 46 (1997), H. 5 Y1 - 1997 SN - 0018-9456 SP - 1120 EP - 1127 ER - TY - JOUR A1 - Hagemann, Hans-Jürgen A1 - Hennings, D. T1 - Reversible Weight change of acceptor-doped BaTiO3. Hagemann, H. J.; Hennings, D. JF - Journal of the American Ceramic Society. 64 (1981) Y1 - 1981 SN - 0002-7820 SP - 590 EP - 594 ER - TY - JOUR A1 - Orzada, Stephan A1 - Maderwald, Stefan A1 - Poser, Benedikt Andreas A1 - Bitz, Andreas A1 - Quick, Harald H. A1 - Ladd, Mark E. T1 - RF excitation using time interleaved acquisition of modes (TIAMO) to address B1 inhomogeneity in high-field MRI JF - Magnetic Resonance in Medicine N2 - As the field strength and, therefore, the operational frequency in MRI is increased, the wavelength approaches the size of the human head/body, resulting in wave effects, which cause signal decreases and dropouts. Several multichannel approaches have been proposed to try to tackle these problems, including RF shimming, where each element in an array is driven by its own amplifier and modulated with a certain (constant) amplitude and phase relative to the other elements, and Transmit SENSE, where spatially tailored RF pulses are used. In this article, a relatively inexpensive and easy to use imaging scheme for 7 Tesla imaging is proposed to mitigate signal voids due to B1 field inhomogeneity. Two time-interleaved images are acquired using a different excitation mode for each. By forming virtual receive elements, both images are reconstructed together using GRAPPA to achieve a more homogeneous image, with only small SNR and SAR penalty in head and body imaging at 7 Tesla. Y1 - 2010 U6 - http://dx.doi.org/10.1002/mrm.22527 SN - 1522-2594 VL - 64 IS - 2 SP - 327 EP - 333 PB - Wiley-Liss CY - New York ER - TY - JOUR A1 - Hansen, Volkert W. A1 - Bitz, Andreas A1 - Streckert, Joachim R. T1 - RF Exposure of Biological Systems in Radial Waveguides JF - IEEE Transactions on Electromagnetic Compatibility Y1 - 1999 U6 - http://dx.doi.org/10.1109/15.809852 SN - 1558-187X VL - 41 IS - 4 SP - 487 EP - 493 ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Ladd, Mark E. A1 - Bitz, Andreas T1 - RF safety assessment of a bilateral four-channel transmit/receive 7 Tesla breast coil: SAR versus temperature limits JF - Medical Physics Y1 - 2017 U6 - http://dx.doi.org/10.1002/mp.12034 N1 - This article is corrected by: Errata: Erratum: “RF safety assessment of a bilateral four-channel transmit/receive 7 Tesla breast coil: SAR versus tissue temperature limits” [Med. Phys. 44(1), 143–157 (2017)] Volume 44, Issue 2, 772 VL - 44 IS - 1 SP - 143 EP - 157 ER - TY - JOUR A1 - Samm, Doris A1 - Faissner, H. A1 - Heinrigs, W. A1 - Latsch, C. T1 - Richtungsselektive Zähleranordnung zur Messung der Masse Axion-ähnlicher Teilchen / Faissner, H. ; Heinrigs, W. ; Latsch, C.; Preussger, A.; Samm, D. JF - Verhandlungen der Deutschen Physikalischen Gesellschaft. 18 (1983), H. 6 Y1 - 1983 N1 - Frühjahrstagung ... des Fachausschusses Kernphysik und Hochenergiephysik, Sektion B: Teilchenphysik / Deutsche Physikalische Gesellschaft / Wuppertal (Germany), 28-30 Mar 1983 SP - 1213 EP - 1213 ER - TY - JOUR A1 - Wolf, Martin T1 - Risiko- und Maßnahmenmanagement bei der Computervalidierung JF - Pharma-Technologie-Journal (2003) Y1 - 2003 SN - 0931-9700 SP - 50 EP - 62 PB - - ER - TY - JOUR A1 - Ferrein, Alexander A1 - Marais, Stephen A1 - Potgieter, Anet A1 - Steinbauer, Gerald T1 - RoboCup Junior: A vehicle for S&T education in Africa? Y1 - 2011 SN - 978-1-61284-992-8 N1 - AFRICON, 2011 SP - 1 EP - 6 PB - IEEE CY - New York ER - TY - JOUR A1 - Ferrein, Alexander A1 - Steinbauer, Gerald A1 - McPhillips, Graeme A1 - Potgieter, Anet T1 - RoboCup Standard Platform League - Team Zadeat : an intercontinental research effort Y1 - 2008 SP - 1 EP - 7 ER - TY - JOUR A1 - Ferrein, Alexander T1 - Robot controllers for highly dynamic environments with real-time constraints JF - Künstliche Intelligenz : KI. 24 (2010), H. 2 Y1 - 2010 SN - 1610-1987 SP - 175 EP - 178 ER - TY - JOUR A1 - Ferrein, Alexander A1 - Lakemeyer, Gerhard T1 - Roboterfußball - Wissenschaft, die auch Spass macht / Ferrein, Alexander ; Lakemeyer, Gerhard JF - RWTH Themen (2006) Y1 - 2006 SN - 0179-079X SP - 36 EP - 39 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, B. T1 - Robust Algorithms for Txx Network Analyzer Self-Calibration Procedures JF - IEEE transactions on instrumentation and measurement : IM / Institute of Electrical and Electronics Engineers, Instrumentation and Measurement Group. 43 (1994), H. 1 Y1 - 1994 SN - 0018-9456 SP - 18 EP - 23 ER - TY - JOUR A1 - Ferrein, Alexander A1 - Jacobs, Stefan A1 - Schiffer, Stefan A1 - Beck, Daniel T1 - Robust Collision Avoidance in Unknown Domestic Environments / Jacobs, Stefan ; Ferrein, Alexander ; Schiffer, Stefan ; Beck, Daniel ; Lakemeyer, Gerhard JF - ROBOCUP 2009: ROBOT SOCCER WORLD CUP XIII Y1 - 2009 N1 - Lecture Notes in Computer Science ; 5949 SP - 116 EP - 127 PB - Springer CY - Berlin ER - TY - JOUR A1 - Krause, Gregor A1 - Forsyth, Paul A. A1 - Peter, Till T1 - Robuste Filter in der Energieversorgung / Paul A. Forsyth, Gregor Krause, Till Peter JF - ETZ. 114 (1993), H. 22 Y1 - 1993 N1 - Printausgabe: Aachen Eupener Str.: 23 Z 133; Jülich: 63 ZS 035 SP - 1382 EP - 1385 ER - TY - JOUR A1 - Heuermann, Holger A1 - Schiek, Burkhard T1 - Robuster Algorithmus zur Streuparameterbestimmung für systemfehlerkorrigierte Netzwerkanalysatoren JF - Kleinheubacher Berichte : Vorträge und Berichte der gemeinsamen Tagung des U.R.S.I.-Landesausschusses in der Bundesrepublik Deutschland / Hrsg.: Deutsche Telekom AG. 35. 1991 (1991) Y1 - 1991 SP - 555 EP - 556 ER - TY - JOUR A1 - Hüning, Felix T1 - Robusti affidabili per le Sfide dell’automotive JF - Selezione di Elettronica (2008) Y1 - 2008 SP - 116 EP - 117 PB - - ER - TY - JOUR A1 - Hartung, Frank A1 - Baldo, N. A1 - Horn, U. A1 - Kampmann, M. T1 - RTCP feedback based transmission rate control for 3G wireless multimedia streaming / Baldo, N. ; Horn, U. ; Kampmann, M. ; Hartung, F. ; JF - 15th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, 2004. PIMRC 2004. Date:5-8 Sept. 2004 ; Vol. 3 Y1 - 2004 N1 - http://dx.doi.org/10.1109/PIMRC.2004.1368313 SP - 1817 EP - 1821 ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Ladd, Mark E. A1 - Clemens, Markus A1 - Bitz, Andreas T1 - Safety of subjects during radiofrequency exposure in ultra-high-field magnetic resonance imaging JF - IEEE Letters on Electromagnetic Compatibility Practice and Applications N2 - Magnetic resonance imaging (MRI) is one of the most important medical imaging techniques. Since the introduction of MRI in the mid-1980s, there has been a continuous trend toward higher static magnetic fields to obtain i.a. a higher signal-to-noise ratio. The step toward ultra-high-field (UHF) MRI at 7 Tesla and higher, however, creates several challenges regarding the homogeneity of the spin excitation RF transmit field and the RF exposure of the subject. In UHF MRI systems, the wavelength of the RF field is in the range of the diameter of the human body, which can result in inhomogeneous spin excitation and local SAR hotspots. To optimize the homogeneity in a region of interest, UHF MRI systems use parallel transmit systems with multiple transmit antennas and time-dependent modulation of the RF signal in the individual transmit channels. Furthermore, SAR increases with increasing field strength, while the SAR limits remain unchanged. Two different approaches to generate the RF transmit field in UHF systems using antenna arrays close and remote to the body are investigated in this letter. Achievable imaging performance is evaluated compared to typical clinical RF transmit systems at lower field strength. The evaluation has been performed under consideration of RF exposure based on local SAR and tissue temperature. Furthermore, results for thermal dose as an alternative RF exposure metric are presented. Y1 - 2020 SN - 2637-6423 U6 - http://dx.doi.org/10.1109/LEMCPA.2020.3029747 VL - 2 IS - 3 SP - 1 EP - 8 PB - IEEE CY - New York, NY ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Ladd, Mark E. A1 - Bitz, Andreas T1 - SAR Simulations & Safety JF - NeuroImage Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.neuroimage.2017.03.035 SN - 1053-8119 IS - Epub ahead of print PB - Elsevier CY - Amsterdam ER -