@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} } @inproceedings{MuellerSchmittLeiseetal.2021, author = {M{\"u}ller, Tim M. and Schmitt, Andreas and Leise, Philipp and Meck, Tobias and Altherr, Lena and Pelz, Peter F. and Pfetsch, Marc E.}, title = {Validation of an optimized resilient water supply system}, series = {Uncertainty in Mechanical Engineering}, booktitle = {Uncertainty in Mechanical Engineering}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-77255-0}, doi = {10.1007/978-3-030-77256-7_7}, pages = {70 -- 80}, year = {2021}, abstract = {Component failures within water supply systems can lead to significant performance losses. One way to address these losses is the explicit anticipation of failures within the design process. We consider a water supply system for high-rise buildings, where pump failures are the most likely failure scenarios. We explicitly consider these failures within an early design stage which leads to a more resilient system, i.e., a system which is able to operate under a predefined number of arbitrary pump failures. We use a mathematical optimization approach to compute such a resilient design. This is based on a multi-stage model for topology optimization, which can be described by a system of nonlinear inequalities and integrality constraints. Such a model has to be both computationally tractable and to represent the real-world system accurately. We therefore validate the algorithmic solutions using experiments on a scaled test rig for high-rise buildings. The test rig allows for an arbitrary connection of pumps to reproduce scaled versions of booster station designs for high-rise buildings. We experimentally verify the applicability of the presented optimization model and that the proposed resilience properties are also fulfilled in real systems.}, 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} } @inproceedings{RauschFriesenAltherretal.2018, author = {Rausch, Lea and Friesen, John and Altherr, Lena and Pelz, Peter F.}, title = {Using mixed-integer programming for the optimal design of water supply networks for slums}, series = {Operations Research Proceedings 2017}, booktitle = {Operations Research Proceedings 2017}, editor = {Kliewer, Natalia and Ehmke, Jan Fabian and Bornd{\"o}rfer, Ralf}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-89919-0 (Print)}, doi = {10.1007/978-3-319-89920-6_68}, pages = {509 -- 516}, year = {2018}, abstract = {The UN sets the goal to ensure access to water and sanitation for all people by 2030. To address this goal, we present a multidisciplinary approach for designing water supply networks for slums in large cities by applying mathematical optimization. The problem is modeled as a mixed-integer linear problem (MILP) aiming to find a network describing the optimal supply infrastructure. To illustrate the approach, we apply it on a small slum cluster in Dhaka, Bangladesh.}, 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} } @inproceedings{FuchsRitzStrauch2012, author = {Fuchs, Britta and Ritz, Thomas and Strauch, Jakob}, title = {Usability of mobile applications : dissemination of usability engineering in small and medium enterprises}, series = {Proceedings of the International Conference on Data Communication Networking, e-Business and Optical Communication Systems : Rome, Italy, 24 - 27 July, 2012 ; [integrated in the ICETE (International Conference on e-Business and Telecommunications)]}, booktitle = {Proceedings of the International Conference on Data Communication Networking, e-Business and Optical Communication Systems : Rome, Italy, 24 - 27 July, 2012 ; [integrated in the ICETE (International Conference on e-Business and Telecommunications)]}, editor = {Obaidat, Mohammad S.}, publisher = {SciTePress}, address = {[Lissabon]}, isbn = {978-989-8565-23-5}, pages = {272 -- 277}, year = {2012}, language = {en} } @inproceedings{FuchsRitz2014, author = {Fuchs, Britta and Ritz, Thomas}, title = {Usability for Blended Shopping - Solving Major Flaws by Applying Usability Engineering and Proven Integration Technologies}, series = {Proceedings of the 11th International Conference on e-Business, ICE-B 2014, Vienna, Austria}, booktitle = {Proceedings of the 11th International Conference on e-Business, ICE-B 2014, Vienna, Austria}, isbn = {978-989-758-043-7}, doi = {10.5220/0005113502160223}, pages = {216 -- 223}, year = {2014}, language = {en} } @article{FoltzSchneiderWolfetal.2008, author = {Foltz, Christian and Schneider, Nicole and Wolf, Martin R. 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} } @book{BenknerStepping2002, author = {Benkner, Thorsten and Stepping, Christoph}, title = {UMTS - Universal Mobile Telecommunications System}, publisher = {Schlembach}, address = {Weil der Stadt}, isbn = {3-935340-07-9}, pages = {XVI, 511 S. : graph. Darst.}, 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} } @inproceedings{WalterGligorevicDetertetal.2010, author = {Walter, Michael and Gligorevic, Snjezana and Detert, Thorben and Schnell, Michael}, title = {UHF/VHF air-to-air propagation measurements}, series = {Proceedings of the Fourth European Conference on Antennas and Propagation (EuCAP) : 12 - 16 April 2010, Barcelona, Spain}, booktitle = {Proceedings of the Fourth European Conference on Antennas and Propagation (EuCAP) : 12 - 16 April 2010, Barcelona, Spain}, organization = {European Association on Antennas and Propagation}, isbn = {978-1-4244-6431-9 ; 978-84-7653-472-4}, pages = {1 -- 5}, year = {2010}, language = {en} } @inproceedings{FerreinBharatheeshaSchifferetal.2019, author = {Ferrein, Alexander and Bharatheesha, Mukunda and Schiffer, Stefan and Corbato, Carlos Hernandez}, title = {TRROS 2018 : Teaching Robotics with ROS Workshop at ERF 2018; Proceedings of the Workshop on Teaching Robotics with ROS (held at ERF 2018), co-located with European Robotics Forum 2018 (ERF 2018), Tampere, Finland, March 15th, 2018}, series = {CEUR Workshop Proceedings}, booktitle = {CEUR Workshop Proceedings}, number = {Vol-2329}, issn = {1613-0073}, pages = {68 Seiten}, year = {2019}, language = {en} } @inproceedings{BensbergAuthCzarneckietal.2018, author = {Bensberg, Frank and Auth, Gunnar and Czarnecki, Christian and W{\"o}rndle, Christopher}, title = {Transforming literature-intensive research processes through text analytics - design, implementation and lessons learned}, editor = {Kemal İlter, H.}, doi = {10.6084/m9.figshare.7582073.v1}, pages = {9 Seiten}, year = {2018}, abstract = {The continuing growth of scientific publications raises the question how research processes can be digitalized and thus realized more productively. Especially in information technology fields, research practice is characterized by a rapidly growing volume of publications. For the search process various information systems exist. However, the analysis of the published content is still a highly manual task. Therefore, we propose a text analytics system that allows a fully digitalized analysis of literature sources. We have realized a prototype by using EBSCO Discovery Service in combination with IBM Watson Explorer and demonstrated the results in real-life research projects. Potential addressees are research institutions, consulting firms, and decision-makers in politics and business practice.}, language = {en} } @misc{WaicziesKuehneWinteretal.2013, author = {Waiczies, Helmar and K{\"u}hne, Andr{\´e} and Winter, Lukas and Frauenrath, Tobias and Hoffmann, Werner and Ittermann, Bernd and Waiczies, Sonia and Niendorf, Thoralf}, title = {Towards theranostics of rheumatoid arthritis: 1H/19F imaging of non-steroidal anti-inflammatory drugs in hand and wrist at 7 Tesla}, series = {2013 ISMRM Annual Meeting Proceedings}, journal = {2013 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2013}, abstract = {We have developed a double-tuned ¹H/¹⁹F birdcage resonator dedicated for hand and wrist imaging at 7 T to locally image non-steroidal anti-inflammatory drugs (NSAID) such as 2-{[3-(Trifluoromethyl) phenyl]amino}benzoic acid. The preliminary in vivo images acquired by the double-tuned ¹H/¹⁹F birdcage resonator demonstrate the feasibility for ¹H/¹⁹F hand- and wrist-imaging at 7 T. While the diagnostic quality of the coil needs to be assessed in patients with inflammatory rheumatoid disease, first ¹⁹F images of the NSAID are encouraging, and point towards the prospect of applying ¹⁹F-MRI to visualize and quantify the concentration of therapeutically-active compound at the sites of inflammation.}, language = {en} } @incollection{PriedeFerrein2013, author = {Priede, Gareth and Ferrein, Alexander}, title = {Towards passive walking for the fully-actuated biped robot Nao}, series = {Emerging trends in computing, informatics, systems sciences, and engineering. (Lecture notes in electrical engineering : vol. 151)}, booktitle = {Emerging trends in computing, informatics, systems sciences, and engineering. (Lecture notes in electrical engineering : vol. 151)}, publisher = {Springer}, address = {New York, NY}, isbn = {978-1-4614-3557-0 ; 978-1-4614-3558-7}, doi = {10.1007/978-1-4614-3558-7_18}, pages = {225 -- 236}, year = {2013}, abstract = {Many biped robots deploy a form of gait that follows the zero moment point (ZMP) approach, that is, the robot is in a stable position at any point in time. This requires the robot to be fully actuated. While very stable, the draw-backs of this approach are a fairly slow gait and high energy consumption. An alternative approach is the so-called passive-dynamic walking, where the gait makes use of the inertia and dynamic stability of the robot. In this paper we describe our ongoing work of combining the principles of passive-dynamic walking on the fully-actuated biped robot Nao, which is also deployed for robotic soccer applications. We present a simple controller that allows the robot to stably rock sidewards, showing a closed limit-cycle. We discuss first results of superimposing a forward motion on the sidewards motion. Based on this we expect to endow the Nao with a fast, robust, and stable passive-dynamic walk on the fully-actuated Nao in the future.}, 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} } @inproceedings{SerrorHenzeHacketal.2018, author = {Serror, Martin and Henze, Martin and Hack, Sacha and Schuba, Marko and Wehrle, Klaus}, title = {Towards in-network security for smart homes}, series = {13th International Conference on Availability, Reliability and Security, ARES 2018; Hamburg; Germany; 27 August 2018 through 30 August 2018}, booktitle = {13th International Conference on Availability, Reliability and Security, ARES 2018; Hamburg; Germany; 27 August 2018 through 30 August 2018}, isbn = {978-145036448-5}, doi = {10.1145/3230833.3232802}, pages = {Article numer 3232802}, year = {2018}, language = {en} }