@inproceedings{UsaiCorucciGligorevicetal.2011, author = {Usai, Pierpaolo and Corucci, Alessandro and Gligorevic, Snjezana and Monorchio, Agostino}, title = {Estimation of airport surface propagation channel: ray tracing model and measurements}, series = {Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP) : 11 - 15 April 2011, Rome, Italy}, booktitle = {Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP) : 11 - 15 April 2011, Rome, Italy}, organization = {European Association on Antennas and Propagation}, isbn = {978-1-4577-0250-1}, pages = {1634 -- 1638}, year = {2011}, language = {en} } @article{UmutluOrzadaKinneretal.2011, author = {Umutlu, Lale and Orzada, Stephan and Kinner, Sonja and Maderwald, Stefan and Bronte, Irina and Bitz, Andreas and Kraff, Oliver and Ladd, Susanne C. and Antoch, Gerald and Ladd, Mark E. and Quick, Harald H. and Lauenstein, Thomas C.}, title = {Renal imaging at 7 Tesla: preliminary results}, series = {European Radiology}, volume = {21}, journal = {European Radiology}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {1432-1084}, pages = {841 -- 849}, year = {2011}, abstract = {Objective To investigate the feasibility of 7T MR imaging of the kidneys utilising a custom-built 8-channel transmit/receive radiofrequency body coil. Methods In vivo unenhanced MR was performed in 8 healthy volunteers on a 7T whole-body MR system. After B0 shimming the following sequences were obtained: 1) 2D and 3D spoiled gradient-echo sequences (FLASH, VIBE), 2) T1-weighted 2D in and opposed phase 3) True-FISP imaging and 4) a T2-weighted turbo spin echo (TSE) sequence. Visual evaluation of the overall image quality was performed by two radiologists. Results Renal MRI at 7T was feasible in all eight subjects. Best image quality was found using T1-weighted gradient echo MRI, providing high anatomical details and excellent conspicuity of the non-enhanced vasculature. With successful shimming, B1 signal voids could be effectively reduced and/or shifted out of the region of interest in most sequence types. However, T2-weighted TSE imaging remained challenging and strongly impaired because of signal heterogeneities in three volunteers. Conclusion The results demonstrate the feasibility and diagnostic potential of dedicated 7T renal imaging. Further optimisation of imaging sequences and dedicated RF coil concepts are expected to improve the acquisition quality and ultimately provide high clinical diagnostic value.}, language = {en} } @article{SchubertScholl2011, author = {Schubert, Nicole and Scholl, Ingrid}, title = {Comparing GPU-based multi-volume ray casting techniques}, series = {Computer Science - Research and Development}, volume = {26}, journal = {Computer Science - Research and Development}, number = {12}, publisher = {Springer}, address = {Berlin}, isbn = {1865-2042}, pages = {39 -- 50}, year = {2011}, language = {en} } @article{SchollAachDesernoetal.2011, author = {Scholl, Ingrid and Aach, Til and Deserno, Thomas M. and Kuhlen, Torsten}, title = {Challenges of medical image processing}, series = {Computer Science - Research and Development}, volume = {26}, journal = {Computer Science - Research and Development}, number = {1-2}, publisher = {Springer}, address = {Berlin}, isbn = {1865-2042}, pages = {5 -- 13}, year = {2011}, language = {en} } @inproceedings{SchneckenburgerFranzenGligorevicetal.2011, author = {Schneckenburger, N. and Franzen, N. and Gligorevic, Snjezana and Schnell, M.}, title = {L-band compatibility of LDACS1}, series = {IEEE/AIAA 30th Digital Avionics Systems Conference (DASC) : 16 - 20 Oct. 2011, Seattle, Wash.}, booktitle = {IEEE/AIAA 30th Digital Avionics Systems Conference (DASC) : 16 - 20 Oct. 2011, Seattle, Wash.}, organization = {Institute of Electrical and Electronics Engineers}, isbn = {978-1-61284-797-9}, issn = {2155-7195}, pages = {4C3-1 -- 4C3-11}, year = {2011}, language = {en} } @article{SchifferFerreinLakemeyer2011, author = {Schiffer, Stefan and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {Reasoning with Qualitative Positional Information for Domestic Domains in the Situation Calculus}, series = {Journal of Intelligent \& Robotic Systems}, volume = {63}, journal = {Journal of Intelligent \& Robotic Systems}, number = {2}, publisher = {Springer}, address = {Berlin}, isbn = {0921-0296}, pages = {273 -- 300}, year = {2011}, language = {en} } @inproceedings{SchifferFerreinLakemeyer2011, author = {Schiffer, Stefan and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {Fuzzy representations and control for domestic service robots in Golog}, series = {Intelligent robotics and applications : 4th International conference, ICIRA 2011, Aachen, Germany, December 6-8, 2011, proceedings, part I. (Lecture notes in computer science ; 7102)}, booktitle = {Intelligent robotics and applications : 4th International conference, ICIRA 2011, Aachen, Germany, December 6-8, 2011, proceedings, part I. (Lecture notes in computer science ; 7102)}, isbn = {978-3-642-25486-4}, pages = {241 -- 250}, year = {2011}, language = {en} } @article{SchaeferHoefkenSchuba2011, author = {Schaefer, Thomas and H{\"o}fken, Hans-Wilhelm and Schuba, Marko}, title = {Windows Phone 7 from a Digital Forensics' Perspective}, publisher = {Springer}, address = {Berlin}, year = {2011}, 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{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} }