@article{PrumeZalachasLaskewitzetal.2008, author = {Prume, Klaus and Zalachas, Nicolas and Laskewitz, Bernd and Kamlah, Marc}, title = {Effective Piezoelectric Coefficients of Ferroelectric Thin Films on Elastic Substrates / Zalachas, Nicolas ; Laskewitz, Bernd ; Kamlah, Marc ; Prume, Klaus ; Lapusta, Yuri ; Tiedke, Stephan}, series = {Journal of Intelligent Material Systems and Structures. 20 (2008), H. 6}, journal = {Journal of Intelligent Material Systems and Structures. 20 (2008), H. 6}, isbn = {1045-389X}, pages = {683 -- 695}, year = {2008}, language = {en} } @article{PrumeWaserFrankenetal.2000, author = {Prume, Klaus and Waser, Rainer and Franken, Klaus and Maier, Horst R.}, title = {Finite-Element Analysis of Ceramic Multilayer Capacitors: Modeling and Electrical Impedance Spectroscopy for a Nondestructive Failure Test / Prume, Klaus ; Waser, Rainer ; Franken, Klaus ; Maier, Horst R. ;}, series = {Journal of the American Ceramic Society. 83 (2000), H. 5}, journal = {Journal of the American Ceramic Society. 83 (2000), H. 5}, isbn = {0002-7820}, pages = {1153 -- 1159}, year = {2000}, language = {en} } @article{PrumeWaser2000, author = {Prume, Klaus and Waser, Rainer}, title = {Finite-element simulation of coupled characteristics of ceramic multilayer capacitors under transient electrical loading / Prume, Klaus ; Waser, Rainer}, series = {Proceedings of the 2000 12th IEEE International Symposium on Applications of Ferroelectrics. Vol. 2}, journal = {Proceedings of the 2000 12th IEEE International Symposium on Applications of Ferroelectrics. Vol. 2}, pages = {675 -- 678}, year = {2000}, language = {en} } @article{PrumeTyholdtCalameetal.2007, author = {Prume, Klaus and Tyholdt, F. and Calame, F. and Raeder, H.}, title = {Chemically derived seeding layer for {100}-textured PZT thin films / Tyholdt, F. ; Calame, F. ; Prume, K. ; Raeder, H. ; Muralt, P.}, series = {Journal of Electroceramics. 19 (2007), H. 4}, journal = {Journal of Electroceramics. 19 (2007), H. 4}, isbn = {1385-3449}, pages = {311 -- 314}, year = {2007}, language = {en} } @article{PrumeTiedkeSchmitzetal.2001, author = {Prume, Klaus and Tiedke, S. and Schmitz, T. and Roelofs, A.}, title = {Direct hysteresis measurements of single nanosized ferroelectric capacitors contacted with an atomic force microscope / Tiedke, S. ; Schmitz, T. ; Prume, K. ; Roelofs, A. ; Schneller, T. ; Kall, U. ; Waser, R. ; Ganpule, C. S. ; Nagarajan, V. ; Stanishevs}, series = {Applied Physics Letters. 79 (2001), H. 22}, journal = {Applied Physics Letters. 79 (2001), H. 22}, isbn = {0003-6951}, pages = {3678 -- 3680}, year = {2001}, language = {en} } @article{PrumeRoelofsSchmitzetal.2002, author = {Prume, Klaus and Roelofs, Andreas and Schmitz, Thorsten and Reichenberg, Bernd}, title = {Compensation of the Parasitic Capacitance of a Scanning Force Microscope Cantilever Used for Measurements on Ferroelectric Capacitors of Submicron Size by Means of Finite Element Simulations / Prume, Klaus ; Roelofs, Andreas ; Schmitz, Thorsten ; Reichenb}, series = {Japanese Journal of Applied Physics. 41 (2002), H. 11B}, journal = {Japanese Journal of Applied Physics. 41 (2002), H. 11B}, isbn = {0021-4922}, pages = {7198 -- 7201}, year = {2002}, language = {en} } @article{PrumeReichenbergRoelofsetal.2004, author = {Prume, Klaus and Reichenberg, B. and Roelofs, A. and Waser, R.}, title = {In-situ compensation of the parasitic capacitance for nanoscale hysteresis measurements / Schmitz, T. ; Prume, K. ; Reichenberg, B. ; Roelofs, A. ; Waser, R. ; Tiedke, S.}, series = {Journal of the European Ceramic Society. 24 (2004), H. 6}, journal = {Journal of the European Ceramic Society. 24 (2004), H. 6}, isbn = {0955-2219}, pages = {1145 -- 1147}, year = {2004}, language = {en} } @article{PrumeRaederTyholdtetal.2007, author = {Prume, Klaus and Raeder, H. and Tyholdt, F. and Booij, W. E.}, title = {Taking piezoelectric microsystems from the laboratory to production / Raeder, H. ; Tyholdt, F. ; Booij, W. ; Calame, F. ; Ostbo, N. P. ; Bredesen, R. ; Prume, K. ; Rijnders, G. ; Muralt, P.}, series = {Journal of Electroceramics. 19 (2007), H. 4}, journal = {Journal of Electroceramics. 19 (2007), H. 4}, isbn = {1385-3449}, pages = {357 -- 362}, year = {2007}, language = {en} } @article{PrumePeterRuedigeretal.2005, author = {Prume, Klaus and Peter, F. and R{\"u}diger, A. and Dittmann, R.}, title = {Analysis of shape effects on the piezoresponse in ferroelectric nanograins with and without adsorbates / Peter, F. ; R{\"u}diger, A. ; Dittmann, R. ; Waser, R. ; Szot, K. ; Reichenberg, B. ; Prume, K. ;}, series = {Applied Physics Letters . 87 (2005), H. 8}, journal = {Applied Physics Letters . 87 (2005), H. 8}, isbn = {0003-6951}, pages = {082901 -- 082901-3}, year = {2005}, language = {en} } @article{PrumeMuraltCalameetal.2007, author = {Prume, Klaus and Muralt, Paul and Calame, Florian and Schmitz-Kempen, Thorsten}, title = {Extensive electromechanical characterization of PZT thin films for MEMS applications by electrical and mechanical excitation signals / Prume, Klaus ; Muralt, Paul ; Calame, Florian ; Schmitz-Kempen, Thorsten ; Tiedke, Stephan}, series = {Journal of Electroceramics. 19 (2007), H. 4}, journal = {Journal of Electroceramics. 19 (2007), H. 4}, isbn = {1385-3449}, pages = {407 -- 411}, year = {2007}, language = {en} } @article{PrumeMuraltCalameetal.2007, author = {Prume, Klaus and Muralt, P. and Calame, F. and Schmitz-Kempen, T.}, title = {Piezoelectric thin films: evaluation of electrical and electromechanical characteristics for MEMS devices / Prume, K. ; Muralt, P. ; Calame, F. ; Schmitz-Kempen, T. ; Tiedke, S. ;}, series = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 54 (2007), H. 1}, journal = {IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 54 (2007), H. 1}, isbn = {0885-3010}, pages = {81 -- 14}, year = {2007}, language = {en} } @article{PrumeMeyerWaseretal.2005, author = {Prume, Klaus and Meyer, Ren{\´e} and Waser, Rainer and Schmitz, Torsten}, title = {Dynamic leakage current compensation in ferroelectric thin-film capacitor structures / Meyer, Ren{\´e} ; Waser, Rainer ; Prume, Klaus ; Schmitz, Torsten ; Tiedke, Stephan}, series = {Applied Physics Letters . 86 (2005), H. 14}, journal = {Applied Physics Letters . 86 (2005), H. 14}, isbn = {0003-6951}, pages = {142907-1 -- 142907-3}, year = {2005}, language = {en} } @article{PrumeGerberKuegeleretal.2004, author = {Prume, Klaus and Gerber, Peter and K{\"u}geler, Carsten and Roelofs, Andreas}, title = {Simulation and measurements of the piezoelectric properties response (d33) of piezoelectric layered thin film structures influenced by the top-electrode size / Prume, K. ; Gerber, P. ; K{\"u}geler, C. ; Roelofs, A. ; B{\"o}ttger, U. ; Waser, R. ; Schmitz-Kempen,}, isbn = {0-7803-8410-5}, pages = {7 -- 10}, year = {2004}, language = {en} } @article{PrumeGerberRoelofsetal.2004, author = {Prume, Klaus and Gerber, P. and Roelofs, A. and K{\"u}geler, C.}, title = {Effects of the top-electrode size on the piezoelectric properties (d33 and S) of lead zirconate titanate thin films / Gerber, P. ; Roelofs, A. ; K{\"u}geler, C.; B{\"o}ttger, U. ; Waser, R. ; Prume, K. ;}, series = {Journal of Applied Physics . 96 (2004), H. 5}, journal = {Journal of Applied Physics . 96 (2004), H. 5}, isbn = {0021-8979}, pages = {2800 -- 2804}, year = {2004}, language = {en} } @article{PrumeFrankenMaieretal.2000, author = {Prume, Klaus and Franken, Klaus and Maier, Horst R. and Waser, Rainer}, title = {Finite-Element Analysis of Ceramic Multilayer Capacitors: Failure Probability Caused by Wave Soldering and Bending Loads / Franken, Klaus ; Maier, Horst R. ; Prume, Klaus ; Waser, Rainer}, series = {Journal of the American Ceramic Society. 83 (2000), H. 6}, journal = {Journal of the American Ceramic Society. 83 (2000), H. 6}, isbn = {0002-7820}, pages = {1433 -- 1440}, year = {2000}, language = {en} } @article{PrumeFrankenBoettgeretal.2002, author = {Prume, Klaus and Franken, Klaus and B{\"o}ttger, Ulrich and Waser, Rainer}, title = {Modelling and numerical simulation of the electrical, mechanical, and thermal coupled behaviour of Multilayer capacitors (MLCs) / Prume, Klaus ; Franken, Klaus ; B{\"o}ttger, Ulrich ; Waser, Rainer ; Maier, Horst R.}, series = {Journal of the European Ceramic Society. 22 (2002), H. 8}, journal = {Journal of the European Ceramic Society. 22 (2002), H. 8}, isbn = {0955-2219}, pages = {1285 -- 1296}, year = {2002}, language = {en} } @article{PrumeBooijVogletal.2007, author = {Prume, Klaus and Booij, W. E. and Vogl, A. H. and Wang, D. T.}, title = {A simple and powerful analytical model for MEMS piezoelectric multimorphs / Booij, W. E. ; Vogl, A. H. ; Wang, D. T. ; Tyholdt, F. ; Ostbo, N. P. ; Raeder, H. ; Prume, K.}, series = {Journal of Electroceramics. 19 (2007), H. 4}, journal = {Journal of Electroceramics. 19 (2007), H. 4}, isbn = {1385-3449}, pages = {387 -- 393}, year = {2007}, language = {en} } @article{Prume2007, author = {Prume, Klaus}, title = {Electrical and electromechanical characterization of piezoelectric thin films in view of MEMS application / Tiedke, S. ; Prume, K. ; Schmitz-Kempen, T.;}, pages = {702}, year = {2007}, language = {en} } @article{ProchnowGebingLadageetal.2011, author = {Prochnow, Nora and Gebing, Tina and Ladage, Kerstin and Krause-Finkeldey, Dorothee and Ourdi, Abessamad El and Bitz, Andreas and Streckert, Joachim and Hansen, Volkert and Dermietzel, Rolf}, title = {Electromagnetic field effect or simply stress? Effects of UMTS exposure on hippocampal longterm plasticity in the context of procedure related hormone release}, series = {PLoS one}, volume = {6}, journal = {PLoS one}, number = {5}, publisher = {PLOS}, address = {San Francisco}, doi = {10.1371/journal.pone.0019437}, pages = {e19437}, year = {2011}, abstract = {Harmful effects of electromagnetic fields (EMF) on cognitive and behavioural features of humans and rodents have been controversially discussed and raised persistent concern about adverse effects of EMF on general brain functions. In the present study we applied radio-frequency (RF) signals of the Universal Mobile Telecommunications System (UMTS) to full brain exposed male Wistar rats in order to elaborate putative influences on stress hormone release (corticosteron; CORT and adrenocorticotropic hormone; ACTH) and on hippocampal derived synaptic long-term plasticity (LTP) and depression (LTD) as electrophysiological hallmarks for memory storage and memory consolidation. Exposure was computer controlled providing blind conditions. Nominal brain-averaged specific absorption rates (SAR) as a measure of applied mass-related dissipated RF power were 0, 2, and 10 W/kg over a period of 120 min. Comparison of cage exposed animals revealed, regardless of EMF exposure, significantly increased CORT and ACTH levels which corresponded with generally decreased field potential slopes and amplitudes in hippocampal LTP and LTD. Animals following SAR exposure of 2 W/kg (averaged over the whole brain of 2.3 g tissue mass) did not differ from the sham-exposed group in LTP and LTD experiments. In contrast, a significant reduction in LTP and LTD was observed at the high power rate of SAR (10 W/kg). The results demonstrate that a rate of 2 W/kg displays no adverse impact on LTP and LTD, while 10 W/kg leads to significant effects on the electrophysiological parameters, which can be clearly distinguished from the stress derived background. Our findings suggest that UMTS exposure with SAR in the range of 2 W/kg is not harmful to critical markers for memory storage and memory consolidation, however, an influence of UMTS at high energy absorption rates (10 W/kg) cannot be excluded.}, language = {en} } @article{OssmannKazay2000, author = {Oßmann, Martin and Kazay, B.}, title = {Simple circuit provides high-side current sensing / Ossmann, M ; Kazay, B.}, series = {EDN. 45 (2000), H. 21}, journal = {EDN. 45 (2000), H. 21}, isbn = {0012-7515}, pages = {200 -- 200}, year = {2000}, language = {en} } @article{OssmannKazay1999, author = {Oßmann, Martin and Kazay, B.}, title = {Single mu C pin makes half-duplex RS-232C / Ossmann, M}, series = {EDN. 44 (1999), H. 16}, journal = {EDN. 44 (1999), H. 16}, isbn = {0012-7515}, pages = {118}, year = {1999}, language = {en} } @article{OssmannHattrupBroeck2003, author = {Oßmann, Martin and Hattrup, C. and Broeck, H. W. van der}, title = {Fast estimation techniques for digital control of resonant converters / Hattrup, C.; van der Broeck, H.W.; Ossmann, M.;}, series = {IEEE Transaction on Power Electronics. 18 (2003), H. 1}, journal = {IEEE Transaction on Power Electronics. 18 (2003), H. 1}, isbn = {0885-8993}, pages = {365 -- 372}, year = {2003}, language = {en} } @article{OrzadaSolbachGratzetal.2019, author = {Orzada, Stephan and Solbach, Klaus and Gratz, Marcel and Brunheim, Sascha and Fiedler, Thomas M. and Johst, S{\"o}ren and Bitz, Andreas and Shooshtary, Samaneh and Abuelhaija, Asjraf and Voelker, Maximilian N. and Rietsch, Stefan H. G. and Kraff, Oliver and Maderwald, Stefan and Fl{\"o}ser, Martina and Oehmingen, Mark and Quick, Harald H. and Ladd, Mark E.}, title = {A 32-channel parallel transmit system add-on for 7T MRI}, series = {Plos one}, journal = {Plos one}, doi = {10.1371/journal.pone.0222452}, year = {2019}, language = {en} } @article{OrzadaMaderwaldPoseretal.2010, author = {Orzada, Stephan and Maderwald, Stefan and Poser, Benedikt Andreas and Bitz, Andreas and Quick, Harald H. and Ladd, Mark E.}, title = {RF excitation using time interleaved acquisition of modes (TIAMO) to address B1 inhomogeneity in high-field MRI}, series = {Magnetic Resonance in Medicine}, volume = {64}, journal = {Magnetic Resonance in Medicine}, number = {2}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2594}, doi = {10.1002/mrm.22527}, pages = {327 -- 333}, year = {2010}, abstract = {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.}, language = {en} } @article{OrzadaLaddBitz2016, author = {Orzada, Stephan and Ladd, Mark E. and Bitz, Andreas}, title = {A method to approximate maximum local SAR in multichannel transmit MR systems without transmit phase information}, series = {Magnetic Resonance in Medicine}, volume = {78}, journal = {Magnetic Resonance in Medicine}, number = {2}, publisher = {International Society for Magnetic Resonance in Medicine}, issn = {1522-2594}, doi = {10.1002/mrm.26398}, pages = {805 -- 811}, year = {2016}, abstract = {Purpose To calculate local specific absorption rate (SAR) correctly, both the amplitude and phase of the signal in each transmit channel have to be known. In this work, we propose a method to derive a conservative upper bound for the local SAR, with a reasonable safety margin without knowledge of the transmit phases of the channels. Methods The proposed method uses virtual observation points (VOPs). Correction factors are calculated for each set of VOPs that prevent underestimation of local SAR when the VOPs are applied with the correct amplitudes but fixed phases. Results The proposed method proved to be superior to the worst-case calculation based on the maximum eigenvalue of the VOPs. The mean overestimation for six coil setups could be reduced, whereas no underestimation of the maximum local SAR occurred. In the best investigated case, the overestimation could be reduced from a factor of 3.3 to a factor of 1.7. Conclusion The upper bound for the local SAR calculated with the proposed method allows a fast estimation of the local SAR based on power measurements in the transmit channels and facilitates SAR monitoring in systems that do not have the capability to monitor transmit phases}, language = {en} } @article{OrzadaJohstMaderwaldetal.2013, author = {Orzada, Stephan and Johst, S{\"o}ren and Maderwald, Stefan and Bitz, Andreas and Solbach, Klaus and Ladd, Mark E.}, title = {Mitigation of B1(+) inhomogeneity on single-channel transmit systems with TIAMO}, series = {Magnetic Resonance in Medicine}, volume = {70}, journal = {Magnetic Resonance in Medicine}, number = {1}, publisher = {Wiley}, address = {Weinheim}, issn = {1522-2594}, doi = {10.1002/mrm.24453}, pages = {290 -- 294}, year = {2013}, language = {en} } @article{OrzadaFiedlerBitzetal.2020, author = {Orzada, Stephan and Fiedler, Thomas M. and Bitz, Andreas and Ladd, Mark E. and Quick, Harald H.}, title = {Local SAR compression with overestimation control to reduce maximum relative SAR overestimation and improve multi-channel RF array performance}, series = {Magnetic Resonance Materials in Physics, Biology and Medicine}, journal = {Magnetic Resonance Materials in Physics, Biology and Medicine}, number = {34 (2021)}, publisher = {Springer}, address = {Heidelberg}, isbn = {1352-8661}, doi = {10.1007/s10334-020-00890-0}, pages = {153 -- 164}, year = {2020}, abstract = {Objective In local SAR compression algorithms, the overestimation is generally not linearly dependent on actual local SAR. This can lead to large relative overestimation at low actual SAR values, unnecessarily constraining transmit array performance. Method Two strategies are proposed to reduce maximum relative overestimation for a given number of VOPs. The first strategy uses an overestimation matrix that roughly approximates actual local SAR; the second strategy uses a small set of pre-calculated VOPs as the overestimation term for the compression. Result Comparison with a previous method shows that for a given maximum relative overestimation the number of VOPs can be reduced by around 20\% at the cost of a higher absolute overestimation at high actual local SAR values. Conclusion The proposed strategies outperform a previously published strategy and can improve the SAR compression where maximum relative overestimation constrains the performance of parallel transmission.}, language = {en} } @article{OrzadaBitzSchaeferetal.2011, author = {Orzada, Stephan and Bitz, Andreas and Sch{\"a}fer, Lena C. and Ladd, Susanne C. and Ladd, Mark E. and Maderwald, Stefan}, title = {Open design eight-channel transmit/receive coil for high-resolution and real-time ankle imaging at 7 T}, series = {Medical Physics}, volume = {38}, journal = {Medical Physics}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {2473-4209}, doi = {10.1118/1.3553399}, pages = {1162 -- 1167}, year = {2011}, abstract = {Purpose: At 1.5 T, real-time MRI of joint movement has been shown to be feasible. However, 7 T, provides higher SNR and thus an improved potential for parallel imaging acceleration. The purpose of this work was to build an open, U-shaped eight-channel transmit/receive microstrip coil for 7 T MRI to enable high-resolution and real-time imaging of the moving ankle joint. Methods: A U-shaped eight-channel transmit/receive array for the human ankle was built.urn:x-wiley:00942405:mp3399:equation:mp3399-math-0001-parameters and urn:x-wiley:00942405:mp3399:equation:mp3399-math-0002-factor were measured. SAR calculations of different ankle postures were performed to ensure patient safety. Inhomogeneities in the transmit field consequent to the open design were compensated for by the use of static RF shimming. High-resolution and real-time imaging was performed in human volunteers. Results: The presented array showed good performance with regard to patient comfort and image quality. High acceleration factors of up to 4 are feasible without visible acceleration artifacts. Reasonable image homogeneity was achieved with RF shimming. Conclusions: Open, noncylindrical designs for transmit/receive coils are practical at 7 T and real-time imaging of the moving joint is feasible with the presented coil design.}, language = {en} } @article{OrzadaBitzJohstetal.2017, author = {Orzada, Stephan and Bitz, Andreas and Johst, S{\"o}ren and Gratz, Marcel and V{\"o}lker, Maximilian N. and Kraff, Oliver and Abuelhaija, Ashraf and Fiedler, Thomas M. and Solbach, Klaus and Quick, Harald H. and Ladd, Mark E.}, title = {Analysis of an integrated 8-Channel Tx/Rx body array for use as a body coil in 7-Tesla MRI}, series = {Frontiers in Physics}, volume = {5}, journal = {Frontiers in Physics}, number = {Jun}, issn = {2296-424X}, doi = {10.3389/fphy.2017.00017}, year = {2017}, language = {en} } @article{OrzadaMaderwaldPoseretal.2012, author = {Orzada, S. and Maderwald, S. and Poser, B. A. and Johst, S. and Kannengiesser, S. and Ladd, M. E. and Bitz, Andreas}, title = {Time-interleaved acquisition of modes: an analysis of SAR and image contrast implications}, series = {Magnetic Resonance in Medicine}, volume = {67}, journal = {Magnetic Resonance in Medicine}, number = {4}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2594}, doi = {10.1002/mrm.23081}, pages = {1033 -- 1041}, year = {2012}, abstract = {s the magnetic field strength and therefore the operational frequency in MRI are increased, the radiofrequency wavelength approaches the size of the human head/body, resulting in wave effects which cause signal decreases and dropouts. Especially, whole-body imaging at 7 T and higher is therefore challenging. Recently, an acquisition scheme called time-interleaved acquisition of modes has been proposed to tackle the inhomogeneity problems in high-field MRI. The basic premise is to excite two (or more) different Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-1 modes using static radiofrequency shimming in an interleaved acquisition, where the complementary radiofrequency patterns of the two modes can be exploited to improve overall signal homogeneity. In this work, the impact of time-interleaved acquisition of mode on image contrast as well as on time-averaged specific absorption rate is addressed in detail. Time-interleaved acquisition of mode is superior in Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-2 homogeneity compared with conventional radiofrequency shimming while being highly specific absorption rate efficient. Time-interleaved acquisition of modes can enable almost homogeneous high-field imaging throughout the entire field of view in PD, T2, and T2*-weighted imaging and, if a specified homogeneity criterion is met, in T1-weighted imaging as well.}, language = {en} } @article{NoureddineKraffLaddetal.2017, author = {Noureddine, Yacine and Kraff, Oliver and Ladd, Mark E. and Wrede, Karsten H. and Chen, Bixia and Quick, Harald H. and Schaefers, Gregor and Bitz, Andreas}, title = {In vitro and in silico assessment of RF-induced heating around intracranial aneurysm clips at 7 Tesla}, series = {Magnetic Resonance in Medicine}, journal = {Magnetic Resonance in Medicine}, number = {Early view}, publisher = {Wiley}, address = {Weinheim}, issn = {1522-2594}, doi = {10.1002/mrm.26650}, pages = {14 Seiten}, year = {2017}, language = {en} } @article{NoureddineKraffLaddetal.2019, author = {Noureddine, Yacine and Kraff, Oliver and Ladd, Mark E. and Wrede, Karsten and Chen, Bixia and Quick, Harald H. and Schaefers, Georg and Bitz, Andreas}, title = {Radiofrequency induced heating around aneurysm clips using a generic birdcage head coil at 7 Tesla under consideration of the minimum distance to decouple multiple aneurysm clips}, series = {Magnetic Resonance in Medicine}, journal = {Magnetic Resonance in Medicine}, number = {Early view}, publisher = {Wiley}, address = {Weinheim}, issn = {1522-2594}, doi = {10.1002/mrm.27835}, pages = {1 -- 17}, year = {2019}, language = {en} } @article{NoureddineBitzLaddetal.2015, author = {Noureddine, Yacine and Bitz, Andreas and Ladd, Mark E. and Th{\"u}rling, Markus and Ladd, Susanne C. and Schaefers, Gregor and Kraff, Oliver}, title = {Experience with magnetic resonance imaging of human subjects with passive implants and tattoos at 7 T: a retrospective study}, series = {Magnetic Resonance Materials in Physics, Biology and Medicine}, volume = {28}, journal = {Magnetic Resonance Materials in Physics, Biology and Medicine}, number = {6}, publisher = {Springer}, address = {Berlin}, issn = {1352-8661}, doi = {10.1007/s10334-015-0499-y}, pages = {577 -- 590}, year = {2015}, language = {en} } @article{NiemuellerLakemeyerFerreinetal.2013, author = {Niem{\"u}ller, Tim and Lakemeyer, Gerhard and Ferrein, Alexander and Reuter, S. and Ewert, D. and Jeschke, S. and Pensky, D. and Karras, Ulrich}, title = {Proposal for advancements to the LLSF in 2014 and beyond}, pages = {Publ. online}, year = {2013}, language = {en} } @article{NiemuellerFerreinLakemeyer2010, author = {Niem{\"u}ller, Tim and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {A Lua-based Behavior Engine for Controlling the Humanoid Robot Nao}, series = {RoboCup 2009: Robot Soccer World Cup XIII}, journal = {RoboCup 2009: Robot Soccer World Cup XIII}, pages = {240 -- 251}, year = {2010}, language = {en} } @article{NiemuellerFerreinEckeletal.2011, author = {Niem{\"u}ller, Tim and Ferrein, Alexander and Eckel, Gerhard and Pirro, David and Podbregar, Patrick and Kellner, Tobias and Rath, Christoph and Steinbauer, Gerald}, title = {Providing Ground-truth Data for the Nao Robot Platform}, series = {RoboCup 2010: Robot Soccer World Cup XIV}, journal = {RoboCup 2010: Robot Soccer World Cup XIV}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-20217-9}, pages = {133 -- 144}, year = {2011}, language = {en} } @article{NiemuellerFerreinBecketal.2010, author = {Niem{\"u}ller, Tim and Ferrein, Alexander and Beck, Daniel and Lakemeyer, Gerhard}, title = {Design Principles of the Component-Based Robot Software Framework Fawkes}, series = {Simulation, Modeling, and Programming for Autonomous Robots}, journal = {Simulation, Modeling, and Programming for Autonomous Robots}, pages = {300 -- 311}, year = {2010}, language = {en} } @article{NdoumbeMbonjoMbonjoStreckertBitzetal.2004, author = {Ndoumb{\`e} Mbonjo Mbonjo, H. and Streckert, J. and Bitz, Andreas and Hansen, V. and Glasmachers, A. and Gencol, S. and Rozic, D.}, title = {Generic UMTS test signal for RF bioelectromagnetic studies}, series = {Bioelectromagnetics}, volume = {25}, journal = {Bioelectromagnetics}, number = {6}, issn = {1521-186X}, doi = {10.1002/bem.20007}, pages = {415 -- 425}, year = {2004}, language = {en} } @article{MuellerLeiseLorenzetal.2020, author = {M{\"u}ller, Tim M. and Leise, Philipp and Lorenz, Imke-Sophie and Altherr, Lena and Pelz, Peter F.}, title = {Optimization and validation of pumping system design and operation for water supply in high-rise buildings}, series = {Optimization and Engineering}, volume = {2021}, journal = {Optimization and Engineering}, number = {22}, publisher = {Springer}, issn = {1573-2924}, doi = {10.1007/s11081-020-09553-4}, pages = {643 -- 686}, year = {2020}, abstract = {The application of mathematical optimization methods for water supply system design and operation provides the capacity to increase the energy efficiency and to lower the investment costs considerably. We present a system approach for the optimal design and operation of pumping systems in real-world high-rise buildings that is based on the usage of mixed-integer nonlinear and mixed-integer linear modeling approaches. In addition, we consider different booster station topologies, i.e. parallel and series-parallel central booster stations as well as decentral booster stations. To confirm the validity of the underlying optimization models with real-world system behavior, we additionally present validation results based on experiments conducted on a modularly constructed pumping test rig. Within the models we consider layout and control decisions for different load scenarios, leading to a Deterministic Equivalent of a two-stage stochastic optimization program. We use a piecewise linearization as well as a piecewise relaxation of the pumps' characteristics to derive mixed-integer linear models. Besides the solution with off-the-shelf solvers, we present a problem specific exact solving algorithm to improve the computation time. Focusing on the efficient exploration of the solution space, we divide the problem into smaller subproblems, which partly can be cut off in the solution process. Furthermore, we discuss the performance and applicability of the solution approaches for real buildings and analyze the technical aspects of the solutions from an engineer's point of view, keeping in mind the economically important trade-off between investment and operation costs.}, language = {en} } @article{MuehlBinneboeselKlingeetal.2008, author = {M{\"u}hl, Thomas and Binneb{\"o}sel, Marcel and Klinge, Uwe and Goedderz, Thomas}, title = {New objective measurement to characterize the porosity of textile implants}, series = {Journal of Biomedical Materials Research Part B: Applied Biomaterials. 84B (2008), H. 1}, journal = {Journal of Biomedical Materials Research Part B: Applied Biomaterials. 84B (2008), H. 1}, isbn = {1552-4981}, pages = {176 -- 183}, year = {2008}, language = {en} } @article{Mayer1997, author = {Mayer, Claudia}, title = {L'Est{\´e}tique et le pouvoir: Le discours chaotique de l'Allemagne unifi{\´e}e}, series = {Canadian review of comparative literature : CRCL = Revue canadienne de litt{\´e}rature compar{\´e}e : RCLC / Canadian Comparative Literature Association. 24 (1997), H. 2}, journal = {Canadian review of comparative literature : CRCL = Revue canadienne de litt{\´e}rature compar{\´e}e : RCLC / Canadian Comparative Literature Association. 24 (1997), H. 2}, isbn = {0319-051X}, pages = {297 -- 317}, year = {1997}, language = {en} } @article{Mayer1993, author = {Mayer, Claudia}, title = {Between Trans- and Interdisciplinarity. »Germanistik« and the Dialectic of Inclusion and Exclusion of the Other(s)}, series = {Language and literature today : proceedings of the XIXth triennal congress of the International Federation for Modern Languages and Literatures ; Bras{\´i}lia 22 - 30 August 1993. General ed. Neide de Faria.}, journal = {Language and literature today : proceedings of the XIXth triennal congress of the International Federation for Modern Languages and Literatures ; Bras{\´i}lia 22 - 30 August 1993. General ed. Neide de Faria.}, publisher = {Univ.}, address = {Brasilia}, isbn = {85-230-0405-x}, pages = {958 -- 966}, year = {1993}, language = {en} } @article{Mayer1995, author = {Mayer, Claudia}, title = {Between Resistance and Affirmation: Christa Wolf and German Unification}, series = {Canadian review of comparative literature : CRCL = Revue canadienne de litt{\´e}rature compar{\´e}e / Canadian Comparative Literature Association. 22 (1995), H. 3-4}, journal = {Canadian review of comparative literature : CRCL = Revue canadienne de litt{\´e}rature compar{\´e}e / Canadian Comparative Literature Association. 22 (1995), H. 3-4}, isbn = {0319-051X}, pages = {813 -- 835}, year = {1995}, language = {en} } @article{MausHoefkenSchuba2011, author = {Maus, Stefan and H{\"o}fken, Hans-Wilhelm and Schuba, Marko}, title = {Forensic Analysis of Geodata in Android Smartphones}, pages = {1 -- 11}, year = {2011}, language = {en} } @article{MaasVosLagemaatetal.2014, author = {Maas, Marnix C. and Vos, Eline K. and Lagemaat, Miriam W. and Bitz, Andreas and Orzada, Stephan and Kobus, Thiele and Kraff, Oliver and Maderwald, Stefan and Ladd, Mark E. and Scheenen, Tom W. J.}, title = {Feasibility of T₂-weighted turbo spin echo imaging of the human prostate at 7 tesla}, series = {Magnetic Resonance in Medicine}, volume = {71}, journal = {Magnetic Resonance in Medicine}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1522-2594}, doi = {10.1002/mrm.24818}, pages = {1711 -- 1719}, year = {2014}, abstract = {Purpose To demonstrate that high quality T₂-weighted (T2w) turbo spin-echo (TSE) imaging of the complete prostate can be achieved routinely and within safety limits at 7 T, using an external transceive body array coil only. Methods Nine healthy volunteers and 12 prostate cancer patients were scanned on a 7 T whole-body system. Preparation consisted of B₀ and radiofrequency shimming and localized flip angle calibration. T₁ and T₂ relaxation times were measured and used to define the T2w-TSE protocol. T2w imaging was performed using a TSE sequence (pulse repetition time/echo time 3000-3640/71 ms) with prolonged excitation and refocusing pulses to reduce specific absorption rate. Results High quality T2w TSE imaging was performed in less than 2 min in all subjects. Tumors of patients with gold-standard tumor localization (MR-guided biopsy or prostatectomy) were well visualized on 7 T imaging (n = 3). The number of consecutive slices achievable within a 10-g averaged specific absorption rate limit of 10 W/kg was ≥28 in all subjects, sufficient for full prostate coverage with 3-mm slices in at least one direction. Conclusion High quality T2w TSE prostate imaging can be performed routinely and within specific absorption rate limits at 7 T with an external transceive body array.}, language = {en} } @article{LimpertWiesenFerreinetal.2019, author = {Limpert, Nicolas and Wiesen, Patrick and Ferrein, Alexander and Kallweit, Stephan and Schiffer, Stefan}, title = {The ROSIN Project and its Outreach to South Africa}, series = {R\&D Journal}, volume = {35}, journal = {R\&D Journal}, pages = {1 -- 6}, year = {2019}, language = {en} } @article{LerchlKruegerNiehausetal.2008, author = {Lerchl, Alexander and Kr{\"u}ger, Heike and Niehaus, Michael and Streckert, Joachim R. and Bitz, Andreas and Hansen, Volkert}, title = {Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus)}, series = {Journal of Pineal Research}, volume = {44}, journal = {Journal of Pineal Research}, number = {3}, issn = {1600-079X}, doi = {10.1111/j.1600-079X.2007.00522.x}, pages = {267 -- 272}, year = {2008}, language = {en} } @article{LeiseEsserEichenlaubetal.2021, author = {Leise, Philipp and Eßer, Arved and Eichenlaub, Tobias and Schleiffer, Jean-Eric and Altherr, Lena and Rinderknecht, Stephan and Pelz, Peter F.}, title = {Sustainable system design of electric powertrains - comparison of optimization methods}, series = {Engineering Optimization}, journal = {Engineering Optimization}, publisher = {Taylor \& Francis}, address = {London}, issn = {0305-215X}, doi = {10.1080/0305215X.2021.1928660}, year = {2021}, abstract = {The transition within transportation towards battery electric vehicles can lead to a more sustainable future. To account for the development goal 'climate action' stated by the United Nations, it is mandatory, within the conceptual design phase, to derive energy-efficient system designs. One barrier is the uncertainty of the driving behaviour within the usage phase. This uncertainty is often addressed by using a stochastic synthesis process to derive representative driving cycles and by using cycle-based optimization. To deal with this uncertainty, a new approach based on a stochastic optimization program is presented. This leads to an optimization model that is solved with an exact solver. It is compared to a system design approach based on driving cycles and a genetic algorithm solver. Both approaches are applied to find efficient electric powertrains with fixed-speed and multi-speed transmissions. Hence, the similarities, differences and respective advantages of each optimization procedure are discussed.}, language = {en} } @article{LeingartnerMaurerFerreinetal.2016, author = {Leingartner, Max and Maurer, Johannes and Ferrein, Alexander and Steinbauer, Gerald}, title = {Evaluation of Sensors and Mapping Approaches for Disasters in Tunnels}, series = {Journal of Field Robotics}, volume = {33}, journal = {Journal of Field Robotics}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1556-4967}, doi = {10.1002/rob.21611}, pages = {1037 -- 1057}, year = {2016}, abstract = {Ground or aerial robots equipped with advanced sensing technologies, such as three-dimensional laser scanners and advanced mapping algorithms, are deemed useful as a supporting technology for first responders. A great deal of excellent research in the field exists, but practical applications at real disaster sites are scarce. Many projects concentrate on equipping robots with advanced capabilities, such as autonomous exploration or object manipulation. In spite of this, realistic application areas for such robots are limited to teleoperated reconnaissance or search. In this paper, we investigate how well state-of-the-art and off-the-shelf components and algorithms are suited for reconnaissance in current disaster-relief scenarios. The basic idea is to make use of some of the most common sensors and deploy some widely used algorithms in a disaster situation, and to evaluate how well the components work for these scenarios. We acquired the sensor data from two field experiments, one from a disaster-relief operation in a motorway tunnel, and one from a mapping experiment in a partly closed down motorway tunnel. Based on these data, which we make publicly available, we evaluate state-of-the-art and off-the-shelf mapping approaches. In our analysis, we integrate opinions and replies from first responders as well as from some algorithm developers on the usefulness of the data and the limitations of the deployed approaches, respectively. We discuss the lessons we learned during the two missions. These lessons are interesting for the community working in similar areas of urban search and rescue, particularly reconnaissance and search.}, language = {en} } @article{LagemaatVosMaasetal.2014, author = {Lagemaat, Miriam W. and Vos, Eline K. and Maas, Marnix C. and Bitz, Andreas and Orzada, Stephan and Uden, Mark J. van and Kobus, Thiele and Heerschap, Arend and Scheenen, Tom W. J.}, title = {Phosphorus magnetic resonance spectroscopic imaging at 7 T in patients with prostate cancer}, series = {Investigative Radiology}, volume = {49}, journal = {Investigative Radiology}, number = {5}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia, Pa.}, issn = {1536-0210}, doi = {10.1097/RLI.0000000000000012}, pages = {363 -- 372}, year = {2014}, abstract = {Objectives The aim of this study was to identify characteristics of phosphorus (³¹P) spectra of the human prostate and to investigate changes of individual phospholipid metabolites in prostate cancer through in vivo ³¹P magnetic resonance spectroscopic imaging (MRSI) at 7 T. Materials and Methods In this institutional review board-approved study, 15 patients with biopsy-proven prostate cancer underwent T₂-weighted magnetic resonance imaging and 3-dimensional ³¹P MRSI at 7 T. Voxels were selected at the tumor location, in normal-appearing peripheral zone tissue, normal-appearing transition zone tissue, and in the base of the prostate close to the seminal vesicles. Phosphorus metabolite ratios were determined and compared between tissue types. Results Signals of phosphoethanolamine (PE) and phosphocholine (PC) were present and well resolved in most ³¹P spectra in the prostate. Glycerophosphocholine signals were observable in 43\% of the voxels in malignant tissue, but in only 10\% of the voxels in normal-appearing tissue away from the seminal vesicles. In many spectra, independent of tissue type, 2 peaks resonated in the chemical shift range of inorganic phosphate, possibly representing 2 separate pH compartments. The PC/PE ratio in the seminal vesicles was highly elevated compared with the prostate in 5 patients. A considerable overlap of ³¹P metabolite ratios was found between prostate cancer and normal-appearing prostate tissue, preventing direct discrimination of these tissues. The only 2 patients with high Gleason scores tumors (≥4+5) presented with high PC and glycerophosphocholine levels in their cancer lesions. Conclusions Phosphorus MRSI at 7 T shows distinct features of phospholipid metabolites in the prostate gland and its surrounding structures. In this exploratory study, no differences in ³¹P metabolite ratios were observed between prostate cancer and normal-appearing prostate tissue possibly because of the partial volume effects of small tumor foci in large MRSI voxels.}, language = {en} }