@article{HueningLeineweberJacobsetal.1999, author = {H{\"u}ning, Felix and Leineweber, A. and Jacobs, H. and Lueken, H.}, title = {ε-Fe3N: magnetic structure, magnetization and temperature dependent disorder of nitrogen / Leineweber, A. ; Jacobs, H. ; H{\"u}ning, F. ; Lueken, H. ; Schilder, H. ; Kockelmann, W.}, series = {Journal of Alloys and Compounds. 288 (1999), H. 1-2}, volume = {288}, journal = {Journal of Alloys and Compounds. 288 (1999), H. 1-2}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {1873-4669}, pages = {79 -- 87}, year = {1999}, abstract = {ε-Fe3N has been investigated by time-of-flight neutron diffraction (temperature range 4.2-618 K) and SQUID magnetometry (2-700 K, B≤5 T). A ferromagnetic spin structure is observed with magnetic moments oriented perpendicular to the c-axis of the hexagonal nuclear structure. The magnetic saturation moment of iron is 2.2 μB at 4.2 K from neutron diffraction and 2.0 μB from magnetic measurements and decreases in a Brillouin-like manner on heating to TC=575 K. Above 450 K an increasing but reversible disorder of the nitrogen partial structure is observed.}, language = {en} } @article{LagemaatBreukelsVosetal.2016, author = {Lagemaat, Miriam W. and Breukels, Vincent and Vos, Eline K. and B., Adam and Uden, Mark J. van and Orzada, Stephan and Bitz, Andreas and Maas, Marnix C. and Scheenen, Tom W. J.}, title = {¹H MR spectroscopic imaging of the prostate at 7T using spectral-spatial pulses}, series = {Magnetic Resonance in Medicine}, volume = {75}, journal = {Magnetic Resonance in Medicine}, number = {3}, publisher = {International Society for Magnetic Resonance in Medicine}, issn = {1522-2594}, doi = {10.1002/mrm.25569}, pages = {933 -- 945}, year = {2016}, abstract = {Purpose To assess the feasibility of prostate ¹H MR spectroscopic imaging (MRSI) using low-power spectral-spatial (SPSP) pulses at 7T, exploiting accurate spectral selection and spatial selectivity simultaneously. Methods A double spin-echo sequence was equipped with SPSP refocusing pulses with a spectral selectivity of 1 ppm. Three-dimensional prostate ¹H-MRSI at 7T was performed with the SPSP-MRSI sequence using an 8-channel transmit array coil and an endorectal receive coil in three patients with prostate cancer and in one healthy subject. No additional water or lipid suppression pulses were used. Results Prostate ¹H-MRSI could be obtained well within specific absorption rate (SAR) limits in a clinically feasible time (10 min). Next to the common citrate signals, the prostate spectra exhibited high spermine signals concealing creatine and sometimes also choline. Residual lipid signals were observed at the edges of the prostate because of limitations in spectral and spatial selectivity. Conclusion It is possible to perform prostate ¹H-MRSI at 7T with a SPSP-MRSI sequence while using separate transmit and receive coils. This low-SAR MRSI concept provides the opportunity to increase spatial resolution of MRSI within reasonable scan times.}, language = {en} } @article{HueningHeuermannWache2018, author = {H{\"u}ning, Felix and Heuermann, Holger and Wache, Franz-Josef}, title = {Wireless CAN without WLAN or Bluetooth}, series = {CAN Newsletter}, journal = {CAN Newsletter}, number = {December 2018}, pages = {44 -- 46}, year = {2018}, abstract = {In two developed concepts, dual-mode radio enables CAN participants to be integrated wirelessly into a CAN network. Constructed from a few components, a protocol-free, real-time transmission and thus transparent integration into CAN is provided.}, language = {en} } @article{Benkner1999, author = {Benkner, Thorsten}, title = {Wireless ATM - Broadband Mobile Radio Systems}, series = {Multiaccess, mobility and teletraffic for wireless communications. Workshop on Multiaccess, Mobility and Teletraffic for Wireless Communications <4, 1998, Washington, DC>}, journal = {Multiaccess, mobility and teletraffic for wireless communications. Workshop on Multiaccess, Mobility and Teletraffic for Wireless Communications <4, 1998, Washington, DC>}, publisher = {Kluwer}, address = {Boston [u.a.]}, pages = {155 -- 170}, year = {1999}, 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{FerreinSchifferBooysenetal.2016, author = {Ferrein, Alexander and Schiffer, Stefan and Booysen, T. and Stopforth, R.}, title = {Why it is harder to run RoboCup in South Africa: Experiences from German South African collaborations}, series = {International Journal of Advanced Robotic Systems}, volume = {13}, journal = {International Journal of Advanced Robotic Systems}, number = {5}, issn = {1729-8806}, doi = {10.1177/1729881416662789}, pages = {1 -- 13}, year = {2016}, abstract = {Robots are widely used as a vehicle to spark interest in science and technology in learners. A number of initiatives focus on this issue, for instance, the Roberta Initiative, the FIRST Lego League, the World Robot Olympiad and RoboCup Junior. Robotic competitions are valuable not only for school learners but also for university students, as the RoboCup initiative shows. Besides technical skills, the students get some project exposure and experience what it means to finish their tasks on time. But qualifying students for future high-tech areas should not only be for students from developed countries. In this article, we present our experiences with research and education in robotics within the RoboCup initiative, in Germany and South Africa; we report on our experiences with trying to get the RoboCup initiative in South Africa going. RoboCup has a huge support base of academic institutions in Germany; this is not the case in South Africa. We present our 'north-south' collaboration initiatives in RoboCup between Germany and South Africa and discuss some of the reasons why we think it is harder to run RoboCup in South Africa.}, language = {en} } @article{HartungHusoy1993, author = {Hartung, Frank and Husoy, J. H.}, title = {Wavelet and subband coding of images - A comparative study / Hartung, F. ; Husoy, J. H.}, series = {Mathematical imaging: wavelet applications in signal and image processing : 15 - 16 July 1993, San Diego, California / sponsored and publ. by SPIE - the International Society for Optical Engineering. Andrew F. Laine, chair/ed}, journal = {Mathematical imaging: wavelet applications in signal and image processing : 15 - 16 July 1993, San Diego, California / sponsored and publ. by SPIE - the International Society for Optical Engineering. Andrew F. Laine, chair/ed}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {081941283X}, pages = {242 -- 253}, year = {1993}, language = {en} } @article{ElsenKraissKrumbiegeletal.1999, author = {Elsen, Ingo and Kraiss, Karl-Friedrich and Krumbiegel, Dirk and Walter, Peter and Wickel, Jochen}, title = {Visual information retrieval for 3D product identification: a midterm report}, series = {KI - K{\"u}nstliche Intelligenz}, volume = {13}, journal = {KI - K{\"u}nstliche Intelligenz}, number = {1}, publisher = {Springer}, address = {Berlin}, issn = {1610-1987}, pages = {64 -- 67}, year = {1999}, language = {en} } @article{TheysohnKraffEilersetal.2014, author = {Theysohn, Jens M. and Kraff, Oliver and Eilers, Kristina and Andrade, Dorian and Gerwig, Marcus and Timmann, Dagmar and Schmitt, Franz and Ladd, Mark E. and Ladd, Susanne C. and Bitz, Andreas}, title = {Vestibular effects of a 7 Tesla MRI examination compared to 1.5 T and 0 T in healthy volunteers}, series = {PLoS one}, volume = {9}, journal = {PLoS one}, number = {3}, publisher = {PLOS}, address = {San Francisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0092104}, pages = {e92104}, year = {2014}, abstract = {Ultra-high-field MRI (7 Tesla (T) and above) elicits more temporary side-effects compared to 1.5 T and 3 T, e.g. dizziness or "postural instability" even after exiting the scanner. The current study aims to assess quantitatively vestibular performance before and after exposure to different MRI scenarios at 7 T, 1.5 T and 0 T. Sway path and body axis rotation (Unterberger's stepping test) were quantitatively recorded in a total of 46 volunteers before, 2 minutes after, and 15 minutes after different exposure scenarios: 7 T head MRI (n = 27), 7 T no RF (n = 22), 7 T only B₀ (n = 20), 7 T in \& out B₀ (n = 20), 1.5 T no RF (n = 20), 0 T (n = 15). All exposure scenarios lasted 30 minutes except for brief one minute exposure in 7 T in \& out B₀. Both measures were documented utilizing a 3D ultrasound system. During sway path evaluation, the experiment was repeated with eyes both open and closed. Sway paths for all long-lasting 7 T scenarios (normal, no RF, only B₀) with eyes closed were significantly prolonged 2 minutes after exiting the scanner, normalizing after 15 minutes. Brief exposure to 7 T B₀ or 30 minutes exposure to 1.5 T or 0 T did not show significant changes. End positions after Unterberger's stepping test were significantly changed counter-clockwise after all 7 T scenarios, including the brief in \& out B₀ exposure. Shorter exposure resulted in a smaller alteration angle. In contrast to sway path, reversal of changes in body axis rotation was incomplete after 15 minutes. 1.5 T caused no rotational changes. The results show that exposure to the 7 Tesla static magnetic field causes only a temporary dysfunction or "over-compensation" of the vestibular system not measurable at 1.5 or 0 Tesla. Radiofrequency fields, gradient switching, and orthostatic dysregulation do not seem to play a role.}, language = {en} } @article{Heuermann2006, author = {Heuermann, Holger}, title = {Verringerung des Phasenrauschens von Oszillatoren durch Dual-Mode-Resonatoren}, series = {HF-Report. 20 (2006), H. 5-6}, journal = {HF-Report. 20 (2006), H. 5-6}, isbn = {1431-827X}, pages = {43 -- 48}, year = {2006}, language = {en} } @article{HeuermannIbrahimHillebrand2007, author = {Heuermann, Holger and Ibrahim, Irfan and Hillebrand, J.}, title = {Vector-Signal-Generator with Two ?'?'-PLL's / Ibrahim, I. ; Hillebrand, J. ; Heuermann, H.}, series = {European Conference on Wireless Technologies, 2007. ECWT 2007 ; 8 - 10 October 2007 Munich, Germany}, journal = {European Conference on Wireless Technologies, 2007. ECWT 2007 ; 8 - 10 October 2007 Munich, Germany}, isbn = {978-2-87487-003-3}, pages = {1 -- 4}, year = {2007}, language = {en} } @article{YazdanbakhshSolbachBitz2012, author = {Yazdanbakhsh, Pedram and Solbach, Klaus and Bitz, Andreas}, title = {Variable power combiner for RF mode shimming in 7-T MR imaging}, series = {IEEE Transaction on Biomedical Engineering}, volume = {59}, journal = {IEEE Transaction on Biomedical Engineering}, number = {9}, publisher = {IEEE}, address = {New York}, issn = {1558-2531}, doi = {10.1109/TBME.2012.2205926}, pages = {2549 -- 2557}, year = {2012}, abstract = {This contribution discusses the utilization of RF power in an MRI system with RF mode shimming which enables the superposition of circularly polarized modes of a transmit RF coil array driven by a Butler matrix. Since the required power for the individual modes can vary widely, mode-shimming can result in a significant underutilization of the total available RF power. A variable power combiner (VPC) is proposed to improve the power utilization: it can be realized as a reconfiguration of the MRI transmit system by the inclusion of one additional matrix network which receives the power from all transmit amplifiers at its input ports and provides any desired (combined) power distribution at its output ports by controlling the phase and amplitude of the amplifiers' input signals. The power distribution at the output ports of the VPC is then fed into the "mode" ports of the coil array Butler matrix in order to superimpose the spatial modes at the highest achievable power utilization. The VPC configuration is compared to the standard configuration of the transmit chain of our MRI system with 8 transmit channels and 16 coils. In realistic scenarios, improved power utilization was achieved from 17\% to 60\% and from 14\% to 55\% for an elliptical phantom and a region of interest in the abdomen, respectively, and an increase of the power utilization of 1 dB for a region of interest in the upper leg. In general, it is found that the VPC allows significant improvement in power utilization when the shimming solution demands only a few modes to be energized, while the technique can yield loss in power utilization in cases with many modes required at high power level.}, language = {en} } @article{HagemannIhrig1979, author = {Hagemann, Hans-J{\"u}rgen and Ihrig, H.}, title = {Valence change and phase stability of 3d-doped BaTiO3 annealed in oxygen and hydrogen. Hagemann, H. J.; Ihrig, H.}, series = {Physical Review B.. 20 (1979), H. 9}, journal = {Physical Review B.. 20 (1979), H. 9}, isbn = {1095-3795}, pages = {3871 -- 3878}, year = {1979}, language = {en} } @article{Huening2012, author = {H{\"u}ning, Felix}, title = {Using Trench PowerMOSFETs in Linear Mode}, series = {Power Electronics Europe (2012)}, journal = {Power Electronics Europe (2012)}, publisher = {DFA Media}, address = {Tonbridge}, issn = {1748-3530}, pages = {27 -- 29}, year = {2012}, abstract = {If we think about applications for modern Power MOSFETs using trench technology, running them in linear mode may not be top of the priority list. Yet there are multiple uses for Trench Power MOSFETs in linear mode. In fact, even turning the device on and off in switching applications is a form of linear operation. Also, these components can be run in linear mode to protect the device against voltage surges. This article will illustrate the factors that need to be considered for linear operation and show how Trench Power MOSFETs are suited to it.}, language = {en} } @article{FerreinFritzLakemeyer2005, author = {Ferrein, Alexander and Fritz, Christian and Lakemeyer, Gerhard}, title = {Using Golog for Deliberation and Team Coordination in Robotic Soccer / Ferrein, Alexander ; Fritz, Christian ; Lakemeyer, Gerhard}, series = {K{\"u}nstliche Intelligenz : KI. 19 (2005), H. 1}, journal = {K{\"u}nstliche Intelligenz : KI. 19 (2005), H. 1}, isbn = {0933-1875}, pages = {24 -- 30}, year = {2005}, language = {en} } @article{FoltzSchneiderWolfetal.2008, author = {Foltz, Christian and Schneider, Nicole and Wolf, Martin and Kausch, Bernhard and Schlick, Christopher and Luczak, Holger}, title = {Usability engineering}, series = {Collaborative and distributed chemical engineering : from understanding to substantial design process support; results of the IMPROVE Project. - (Lecture notes in computer science ; 4970)}, journal = {Collaborative and distributed chemical engineering : from understanding to substantial design process support; results of the IMPROVE Project. - (Lecture notes in computer science ; 4970)}, editor = {Nagl, Manfred}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-70552-9}, doi = {10.1007/978-3-540-70552-9_21}, pages = {527 -- 554}, year = {2008}, language = {en} } @article{FerreinJacobsLakemeyer2005, author = {Ferrein, Alexander and Jacobs, Stefan and Lakemeyer, Gerhard}, title = {Unreal Golog Bots / Jacobs, Stefan ; Ferrein, Alexander ; Lakemeyer, Gerhard}, series = {IJCAI-05 Workshop on Reasoning, Representation, and Learning in Computer Games}, journal = {IJCAI-05 Workshop on Reasoning, Representation, and Learning in Computer Games}, pages = {31 -- 36}, year = {2005}, language = {en} } @article{SchubaBusboomHerwonoetal.2002, author = {Schuba, Marko and Busboom, Axel and Herwono, Ian and Zavagli, Guido}, title = {Unambiguous Device Identification and Fast Connection Setup in Bluetooth / Busboom, Axel ; Herwono, Ian ; Schuba, Marko ; Zavagli, Guido}, series = {European wireless 2002 : next generation wireless networks: technologies, protocols, services and applications ; technical sessions: 26 - 28 February 2002, tutorials: 25 February 2002, Centro Affari, Florence, Italy ; proceedings / sponsored by EUREL ... General chair: Luciano Lenzini}, journal = {European wireless 2002 : next generation wireless networks: technologies, protocols, services and applications ; technical sessions: 26 - 28 February 2002, tutorials: 25 February 2002, Centro Affari, Florence, Italy ; proceedings / sponsored by EUREL ... General chair: Luciano Lenzini}, pages = {1 -- 5}, year = {2002}, language = {en} } @article{HeuermannSadeghfamBoehm2005, author = {Heuermann, Holger and Sadeghfam, Arash and Boehm, H.}, title = {Ultra Compact Multi-Mode Filter with Novel Rat-Race Inductor. Sadeghfam, Arash; Heuermann, Holger; Boehm, H.}, series = {Conference proceedings : 3 - 7 October 2005, CNIT la D{\´e}fense, Paris, France; [comprises the] 35th European Microwave Conference 2005 ; The European Conference on Wireless Technology 2005 ; European Radar Conference 2005 ; GAAS 2005, The European Gallium A. Vol. 2}, journal = {Conference proceedings : 3 - 7 October 2005, CNIT la D{\´e}fense, Paris, France; [comprises the] 35th European Microwave Conference 2005 ; The European Conference on Wireless Technology 2005 ; European Radar Conference 2005 ; GAAS 2005, The European Gallium A. Vol. 2}, publisher = {Horizon House Publ}, address = {London}, isbn = {2-9600551-0-1}, pages = {4 pp.}, year = {2005}, language = {en} } @article{BooysenRiegerFerrein2011, author = {Booysen, Tracy and Rieger, Michael and Ferrein, Alexander}, title = {Towards inexpensive robots for science \& technology teaching and education in Africa}, publisher = {IEEE}, address = {New York}, isbn = {978-1-61284-992-8}, pages = {1 -- 6}, year = {2011}, language = {en} }