@article{UmutluBitzMaderwaldetal.2013, author = {Umutlu, Lale and Bitz, Andreas and Maderwald, Stefan and Orzada, Stephan and Kinner, Sonja and Kraff, Oliver and Brote, Irina and Ladd, Susanne C. and Schroeder, Tobias and Forsting, Michael}, title = {Contrast-enhanced ultra-high-field liver MRI: a feasibility trial}, series = {European Journal of Radiology}, volume = {82}, journal = {European Journal of Radiology}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0720-048X}, doi = {10.1016/j.ejrad.2011.07.004}, pages = {760 -- 767}, year = {2013}, 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{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{KraffBitzBreyeretal.2011, author = {Kraff, Oliver and Bitz, Andreas and Breyer, Tobias and Kruszona, Stefan and Maderwald, Stefan and Brote, Irina and Gizewski, Elke R. and Ladd, Mark E. and Quick, Harald H.}, title = {A transmit/receive radiofrequency array for imaging the carotid arteries at 7 Tesla: coil design and first in vivo results}, series = {Investigative Radiology}, volume = {46}, journal = {Investigative Radiology}, number = {4}, publisher = {Wolters Kluwer}, address = {K{\"o}ln}, issn = {1536-0210}, doi = {10.1097/RLI.0b013e318206cee4}, pages = {246 -- 254}, year = {2011}, abstract = {Objective: To develop a transmit/receive radiofrequency (RF) array for magnetic resonance imaging (MRI) of the carotid arteries at 7 T. The prototype is characterized in numerical simulations and bench measurements, and the feasibility of plaque imaging at 7 T is demonstrated in first in vivo images. Materials and Methods: The RF phased array coil consists of 8 surface loop coils. To allow imaging of both sides of the neck, the RF array is divided into 2 coil clusters, each with 4 overlapping loop elements. For safety validation, numerical computations of the RF field distribution and the corresponding specific absorption rate were performed on the basis of a heterogeneous human body model. To validate the coil model, maps of the transmit B1+ field were compared between simulation and measurement. In vivo images of a healthy volunteer and a patient (ulcerating plaque and a 50\% stenosis of the right internal carotid artery) were acquired using a 3-dimensional FLASH sequence with a high isotropic spatial resolution of 0.54 mm as well as using pulse-triggered proton density (PD)/T2-weighted turbo spin echo sequences. Results: Measurements of the S-parameters yielded a reflection and isolation of the coil elements of better than -18 and -13 dB, respectively. Measurements of the g-factor indicated good image quality for parallel imaging acceleration factors up to 2.4. A similar distribution and a very good match of the absolute values were found between the measured and simulated B1+ transmit RF field for the validation of the coil model. In vivo images revealed good signal excitation of both sides of the neck and a high vessel-to-background image contrast for the noncontrast-enhanced 3-dimensional FLASH sequence. Imaging at 7 T could depict the extent of stenosis, and revealed the disruption and ulcer of the plaque. Conclusions: This study demonstrates that 2 four-channel transmit/receive RF arrays for each side of the neck is a suitable concept for in vivo MRI of the carotid arteries at 7 Tesla. Further studies are needed to explore and exploit the full potential of 7 T high-field MRI for carotid atherosclerotic plaque imaging.}, 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{SommerStreckertBitzetal.2004, author = {Sommer, Angela M. and Streckert, Joachim and Bitz, Andreas and Hansen, Volkert W. and Lerchl, Alexander}, title = {No effects of GSM-modulated 900 MHz electromagnetic fields on survival rate and spontaneous development of lymphoma in female AKR/J mice}, series = {BMC Cancer}, volume = {77}, journal = {BMC Cancer}, number = {4}, doi = {10.1186/1471-2407-4-77}, year = {2004}, language = {en} } @article{HansenBitzStreckert1999, author = {Hansen, Volkert W. and Bitz, Andreas and Streckert, Joachim R.}, title = {RF Exposure of Biological Systems in Radial Waveguides}, series = {IEEE Transactions on Electromagnetic Compatibility}, volume = {41}, journal = {IEEE Transactions on Electromagnetic Compatibility}, number = {4}, issn = {1558-187X}, doi = {10.1109/15.809852}, pages = {487 -- 493}, year = {1999}, language = {en} } @article{ElQuardiStreckertBitzetal.2011, author = {El Quardi, A. and Streckert, J. and Bitz, Andreas and M{\"u}nkner, S. and Engel, J. and Hansen, V.}, title = {New fin-line devices for radiofrequency exposure of small biological samples in vitro allowing whole-cell patch clamp recordings}, series = {Bioelectromagnetics}, volume = {32}, journal = {Bioelectromagnetics}, number = {2}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-186X}, doi = {10.1002/bem.20621}, pages = {102 -- 112}, year = {2011}, abstract = {The development and analysis of three waveguides for the exposure of small biological in vitro samples to mobile communication signals at 900 MHz (GSM, Global System for Mobile Communications), 1.8 GHz (GSM), and 2 GHz (UMTS, Universal Mobile Telecommunications System) is presented. The waveguides were based on a fin-line concept and the chamber containing the samples bathed in extracellular solution was placed onto two fins with a slot in between, where the exposure field concentrates. Measures were taken to allow for patch clamp recordings during radiofrequency (RF) exposure. The necessary power for the achievement of the maximum desired specific absorption rate (SAR) of 20 W/kg (average over the mass of the solution) was approximately Pin = 50 mW, Pin = 19 mW, and Pin = 18 mW for the 900 MHz, 1800 MHz, and 2 GHz devices, respectively. At 20 W/kg, a slight RF-induced temperature elevation in the solution of no more than 0.3 °C was detected, while no thermal offsets due to the electromagnetic exposure could be detected at the lower SAR settings (2, 0.2, and 0.02 W/kg). A deviation of 10\% from the intended solution volume yielded a calculated SAR deviation of 8\% from the desired value. A maximum ±10\% variation in the local SAR could occur when the position of the patch clamp electrode was altered within the area where the cells to be investigated were located.}, language = {en} } @article{BitzZhouElQuardietal.2009, author = {Bitz, Andreas and Zhou, Yi and El Quardi, Abdessamad and Streckert, Joachim}, title = {Occupational Exposure at Mobile Communication Base Station Antenna Sites}, series = {Frequenz}, volume = {63}, journal = {Frequenz}, number = {7-8}, issn = {2191-6349}, doi = {10.1515/FREQ.2009.63.7-8.123}, pages = {123 -- 128}, year = {2009}, language = {en} } @article{KraffBitzKruszonaetal.2009, author = {Kraff, Oliver and Bitz, Andreas and Kruszona, Stefan and Orzada, Stephan and Schaefer, Lena C. and Theysohn, Jens M. and Maderwald, Stefan and Ladd, Mark E. and Quick, Harald H.}, title = {An eight-channel phased array RF coil for spine MR imaging at 7 T}, series = {Investigative Radiology}, volume = {44}, journal = {Investigative Radiology}, number = {11}, publisher = {Lippincott Williams \& Wilkins}, issn = {1536-0210}, doi = {10.1097/RLI.0b013e3181b24ab7}, pages = {734 -- 740}, year = {2009}, language = {en} } @article{SchlamannYoonMaderwaldetal.2009, author = {Schlamann, M. and Yoon, M.-S. and Maderwald, S. and Pietrzyk, T. and Bitz, Andreas and Gerwig, M. and Forsting, M. and Ladd, S. C. and Ladd, M. E. and Kastrup, O.}, title = {Auswirkungen der Magnetresonanztomografie auf die Elektrophysiologie des motorischen Kortex: eine Studie mit transkranieller Magnetstimulation}, series = {R{\"o}Fo - Fortschritte auf dem Giebiet der R{\"o}ntgenstrahlen und der bildgebenden Verfahren}, volume = {181}, journal = {R{\"o}Fo - Fortschritte auf dem Giebiet der R{\"o}ntgenstrahlen und der bildgebenden Verfahren}, number = {3}, publisher = {Thieme}, address = {Stuttgart}, issn = {1438-9029}, doi = {10.1055/s-0028-1109038}, pages = {215 -- 219}, year = {2009}, language = {de} } @article{KlompBitzHeerschapetal.2009, author = {Klomp, D. W. J. and Bitz, Andreas and Heerschap, A. and Scheenen, T. W. J.}, title = {Proton spectroscopic imaging of the human prostate at 7 T}, series = {NMR in Biomedicine}, volume = {22}, journal = {NMR in Biomedicine}, number = {5}, issn = {1099-1492}, doi = {10.1002/nbm.1360}, pages = {495 -- 501}, year = {2009}, 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{ReinhardtBitzElOuardietal.2007, author = {Reinhardt, T. and Bitz, Andreas and El Ouardi, A. and Streckert, J. and Sommer, A. and Lerchl, A. and Hansen, V.}, title = {Exposure set-ups for in vivo experiments using radial waveguides}, series = {Radiation Protection Dosimetry}, volume = {124}, journal = {Radiation Protection Dosimetry}, number = {1}, issn = {1742-3406}, doi = {10.1093/rpd/ncm370}, pages = {21 -- 26}, year = {2007}, language = {en} } @article{SommerBitzStreckertetal.2007, author = {Sommer, Angela M. and Bitz, Andreas and Streckert, Joachim and Hansen, Volkert W. and Lerchl, Alexander}, title = {Lymphoma development in mice chronically exposed to UMTS-modulated radiofrequency electromagnetic fields}, series = {Radiation Research}, volume = {168}, journal = {Radiation Research}, number = {1}, issn = {1938-5404}, doi = {10.1667/RR0857.1}, pages = {72 -- 80}, year = {2007}, language = {en} } @article{SukhotinaStreckertBitzetal.2006, author = {Sukhotina, Irina and Streckert, Joachim R. and Bitz, Andreas and Hansen, Volkert W. and Lerchl, Alexander}, title = {1800 MHz electromagnetic field effects on melatonin release from isolated pineal glands}, series = {Journal of Pineal Research}, volume = {40}, journal = {Journal of Pineal Research}, number = {1}, issn = {1600-079X}, doi = {10.1111/j.1600-079X.2005.00284.x}, pages = {86 -- 91}, year = {2006}, language = {en} } @article{FrankeStreckertBitzetal.2005, author = {Franke, Helmut and Streckert, Joachim and Bitz, Andreas and Goeke, Johannes and Hansen, Volkert and Ringelstein, E. Bernd and Nattk{\"a}mper, Heiner and Galle, Hans-Joachim and St{\"o}gbauer, Florian}, title = {Effects of Universal Mobile Telecommunications System (UMTS) electromagnetic fields on the blood-brain barrier in vitro}, series = {Radiation Research}, volume = {164}, journal = {Radiation Research}, number = {3}, issn = {1938-5404}, doi = {10.1667/RR3424.1}, pages = {258 -- 269}, year = {2005}, language = {en} } @article{WissenBogdanskiScheeretal.2005, author = {Wissen, M. and Bogdanski, N. and Scheer, H.-C. and Bitz, Andreas and Ahrens, G. and Gruetzner, G.}, title = {Implication of the light polarisation for UV curing of pre-patterned resists}, series = {Microelectronic Engineering}, volume = {78-79}, journal = {Microelectronic Engineering}, issn = {0167-9317}, doi = {10.1016/j.mee.2004.12.099}, pages = {659 -- 664}, year = {2005}, language = {en} } @article{LambersBragard2017, author = {Lambers, Andreas and Bragard, Michael}, title = {Kinetische Skulptur - Treffen sich ein E-Techniker und ein K{\"u}nstler ...}, series = {Elektor : learn, design, share}, volume = {48}, journal = {Elektor : learn, design, share}, number = {9}, publisher = {Elektor-Verlag}, address = {Aachen}, issn = {0932-5468}, pages = {78 -- 83}, year = {2017}, abstract = {Die Verbindung der Welten dressierter Elektronen und grenzenloser Kreativit{\"a}t bietet ein großes Potential; zum Beispiel bei modernen Skulpturen, deren Form sich durch Motoren ver{\"a}ndern kann. An der FH Aachen wurde ein solches Projekt verwirklicht: Eine Matrix aus Holzkugeln kann Piktogramme anzeigen, aber auch mathematische Funktionen visualisieren. In diesem Artikel beschreiben wir die clevere Ansteuerung der Motoren.}, language = {de} } @article{SchoppDollGraeseretal.2016, author = {Schopp, Christoph and Doll, Timo and Gr{\"a}ser, Ulrich and Harzheim, Thomas and Heuermann, Holger and Kling, Rainer and Marso, Michael}, title = {Capacitively Coupled High-Pressure Lamp Using Coaxial Line Networks}, series = {IEEE Transactions on Microwave Theory and Techniques}, volume = {64}, journal = {IEEE Transactions on Microwave Theory and Techniques}, number = {10}, publisher = {IEEE}, address = {New York, NY}, issn = {0018-9480}, doi = {10.1109/TMTT.2016.2600326}, pages = {3363 -- 3368}, year = {2016}, abstract = {This paper describes the development of a capacitively coupled high-pressure lamp with input power between 20 and 43 W at 2.45 GHz, using a coaxial line network. Compared with other electrodeless lamp systems, no cavity has to be used and a reduction in the input power is achieved. Therefore, this lamp is an alternative to the halogen incandescent lamp for domestic lighting. To serve the demands of domestic lighting, the filling of the lamp is optimized over all other resulting requirements, such as high efficacy at low induced powers and fast startups. A workflow to develop RF-driven plasma applications is presented, which makes use of the hot S-parameter technique. Descriptions of the fitting process inside a circuit and FEM simulator are given. Results of the combined ignition and operation network from simulations and measurements are compared. An initial prototype is built and measurements of the lamp's lighting properties are presented along with an investigation of the efficacy optimizations using large signal amplitude modulation. With this lamp, an efficacy of 135 lmW -1 is achieved.}, language = {en} } @article{RietschPfaffenrotBitzetal.2017, author = {Rietsch, Stefan H. G. and Pfaffenrot, Viktor and Bitz, Andreas and Orzada, Stephan and Brunheim, Sascha and Lazik-Palm, Andrea and Theysohn, Jens M. and Ladd, Mark E. and Quick, Harald H. and Kraff, Oliver}, title = {An 8-channel transceiver 7-channel receive RF coil setup for high SNR ultrahigh-field MRI of the shoulder at 7T}, series = {Medical Physics}, journal = {Medical Physics}, number = {Article in press}, publisher = {Wiley}, address = {Hoboken}, issn = {0094-2405}, doi = {10.1002/mp.12612}, year = {2017}, 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{NiemuellerKarrasFerrein2017, author = {Niemueller, Tim and Karras, Ulrich and Ferrein, Alexander}, title = {Meisterschaft der Maschinen: Die Industrial Logistic Liga}, series = {C´t Magazin f{\"u}r Computertechnik}, journal = {C´t Magazin f{\"u}r Computertechnik}, number = {26}, year = {2017}, language = {de} } @article{FerreinSteinbauer2016, author = {Ferrein, Alexander and Steinbauer, Gerald}, title = {The Interplay of Aldebaran and RoboCup}, series = {KI - K{\"u}nstliche Intelligenz}, volume = {30}, journal = {KI - K{\"u}nstliche Intelligenz}, number = {3-4}, publisher = {Springer}, address = {Berlin}, issn = {1610-1987}, doi = {10.1007/s13218-016-0440-1}, pages = {325 -- 326}, year = {2016}, language = {en} } @article{SteinbauerFerrein2016, author = {Steinbauer, Gerald and Ferrein, Alexander}, title = {20 Years of RoboCup}, series = {KI - K{\"u}nstliche Intelligenz}, volume = {30}, journal = {KI - K{\"u}nstliche Intelligenz}, number = {3-4}, publisher = {Springer}, address = {Berlin}, issn = {1610-1987}, doi = {10.1007/s13218-016-0442-z}, pages = {221 -- 224}, year = {2016}, language = {en} } @article{FerreinSteinbauer2016, author = {Ferrein, Alexander and Steinbauer, Gerald}, title = {Looking back on 20 Years of RoboCup}, series = {KI - K{\"u}nstliche Intelligenz}, volume = {30}, journal = {KI - K{\"u}nstliche Intelligenz}, number = {3-4}, publisher = {Springer}, address = {Berlin}, issn = {1610-1987}, doi = {10.1007/s13218-016-0443-y}, pages = {321 -- 323}, year = {2016}, language = {en} } @article{SchifferFerrein2016, author = {Schiffer, Stefan and Ferrein, Alexander}, title = {Decision-Theoretic Planning with Fuzzy Notions in GOLOG}, series = {International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems}, volume = {24}, journal = {International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems}, number = {Issue Suppl. 2}, publisher = {World Scientific}, address = {Singapur}, issn = {1793-6411}, doi = {10.1142/S0218488516400134}, pages = {123 -- 143}, year = {2016}, abstract = {In this paper we present an extension of the action language Golog that allows for using fuzzy notions in non-deterministic argument choices and the reward function in decision-theoretic planning. Often, in decision-theoretic planning, it is cumbersome to specify the set of values to pick from in the non-deterministic-choice-of-argument statement. Also, even for domain experts, it is not always easy to specify a reward function. Instead of providing a finite domain for values in the non-deterministic-choice-of-argument statement in Golog, we now allow for stating the argument domain by simply providing a formula over linguistic terms and fuzzy uents. In Golog's forward-search DT planning algorithm, these formulas are evaluated in order to find the agent's optimal policy. We illustrate this in the Diner Domain where the agent needs to calculate the optimal serving order.}, language = {en} } @article{HueningHeuermannWacheetal.2018, author = {H{\"u}ning, Felix and Heuermann, Holger and Wache, Franz-Josef and Jajo, Rami Audisho}, title = {A new wireless sensor interface using dual-mode radio}, series = {Journal of Sensors and Sensor Systems : JSSS}, volume = {Volume 7}, journal = {Journal of Sensors and Sensor Systems : JSSS}, number = {2}, publisher = {Copernicus Publ.}, address = {G{\"o}ttingen}, doi = {10.5194/jsss-7-507-2018}, pages = {507 -- 515}, year = {2018}, abstract = {The integration of sensors is one of the major tasks in embedded, control and "internet of things" (IoT) applications. For the integration mainly digital interfaces are used, starting from rather simple pulse-width modulation (PWM) interface to more complex interfaces like CAN (Controller Area Network). Even though these interfaces are tethered by definition, a wireless realization is highly welcome in many applications to reduce cable and connector cost, increase the flexibility and realize new emerging applications like wireless control systems. Currently used wireless solutions like Bluetooth, WirelessHART or IO-Link Wireless use dedicated communication standards and corresponding higher protocol layers to realize the wireless communication. Due to the complexity of the communication and the protocol handling, additional latency and jitter are introduced to the data communication that can meet the requirements for many applications. Even though tunnelling of other bus data like CAN data is generally also possible the latency and jitter prevent the tunnelling from being transparent for the bus system. Therefore a new basic technology based on dual-mode radio is used to realize a wireless communication on the physical layer only, enabling a reliable and real-time data transfer. As this system operates on the physical layer it is independent of any higher layers of the OSI (open systems interconnection) model. Hence it can be used for several different communication systems to replace the tethered physical layer. A prototype is developed and tested for real-time wireless PWM, SENT (single-edge nibble transmission) and CAN data transfer with very low latency and jitter.}, language = {en} } @article{SchifferFerrein2018, author = {Schiffer, Stefan and Ferrein, Alexander}, title = {ERIKA—Early Robotics Introduction at Kindergarten Age}, series = {Multimodal Technologies Interact}, volume = {2}, journal = {Multimodal Technologies Interact}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2414-4088}, doi = {10.3390/mti2040064}, pages = {15}, year = {2018}, abstract = {In this work, we report on our attempt to design and implement an early introduction to basic robotics principles for children at kindergarten age. One of the main challenges of this effort is to explain complex robotics contents in a way that pre-school children could follow the basic principles and ideas using examples from their world of experience. What sets apart our effort from other work is that part of the lecturing is actually done by a robot itself and that a quiz at the end of the lesson is done using robots as well. The humanoid robot Pepper from Softbank, which is a great platform for human-robot interaction experiments, was used to present a lecture on robotics by reading out the contents to the children making use of its speech synthesis capability. A quiz in a Runaround-game-show style after the lecture activated the children to recap the contents they acquired about how mobile robots work in principle. In this quiz, two LEGO Mindstorm EV3 robots were used to implement a strongly interactive scenario. Besides the thrill of being exposed to a mobile robot that would also react to the children, they were very excited and at the same time very concentrated. We got very positive feedback from the children as well as from their educators. To the best of our knowledge, this is one of only few attempts to use a robot like Pepper not as a tele-teaching tool, but as the teacher itself in order to engage pre-school children with complex robotics contents.}, language = {en} } @article{HueningHeuermannWache2018, author = {H{\"u}ning, Felix and Heuermann, Holger and Wache, Franz-Josef}, title = {Wireless CAN}, series = {Etz: Elektrotechnik \& Automation}, volume = {139}, journal = {Etz: Elektrotechnik \& Automation}, number = {10}, publisher = {VDE-Verlag}, address = {Wuppertal}, issn = {0170-1711}, pages = {22 -- 26}, year = {2018}, abstract = {In modernen elektronischen und mechatronischen Systemen, z. B. im industriellen oder automobil Bereich, kommunizieren eingebettete Steuerger{\"a}te und Sensoren vielfach {\"u}ber Bussysteme wie CAN oder LIN. Die Kommunikation findet in der Regel drahtgebunden statt, so dass der Kabelbaum f{\"u}r die Kommunikation sehr groß werden kann. Daher ist es naheliegend, Leitungen und dazugeh{\"o}rige Stecker, z. B. f{\"u}r nicht-sicherheitskritische Komfortsysteme, einzusparen und diese durch gerichtete Funkstrecken f{\"u}r kurze Entfernungen zu ersetzen. Somit k{\"o}nnten Komponenten wie ECUs oder Sensoren kabel- und steckerlos in ein Bussystem integriert werden. Zudem ist eine einfache galvanische und mechanische Trennung zu erreichen. Funk{\"u}bertragung wird bei diesen Bussystemen derzeit nicht eingesetzt, da insbesondere die Echtzeitf{\"a}higkeit und die Robustheit der vorhandenen Funksysteme nicht den Anforderungen der Anwendungen entspricht. Zudem sind bestehende Funksysteme wie WLAN oder Bluetooth im Vergleich zur konventionellen Verkabelung teuer und es besteht hierbei die M{\"o}glichkeit, dass sie ausspioniert werden k{\"o}nnen und so sensible Daten entwendet werden k{\"o}nnen. In dieser Arbeit wird eine alternative Realisierung zu den bestehenden Funksystemen vorgestellt, die aus wenigen Komponenten aufzubauen ist. Es ist eine protokolllose, echtzeitf{\"a}hige {\"U}bertragung m{\"o}glich und somit die transparente Integration in ein Bussystem wie CAN.}, language = {de} } @article{Huening2019, author = {H{\"u}ning, Felix}, title = {Nachr{\"u}stm{\"o}glichkeiten von Dieselfahrzeugen aus technischer Sicht}, series = {Zeitschrift f{\"u}r Verkehrsrecht : NZV}, journal = {Zeitschrift f{\"u}r Verkehrsrecht : NZV}, number = {1}, publisher = {C.H.Beck}, pages = {27 -- 32}, year = {2019}, language = {de} } @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{RietschBrunheimOrzadaetal.2019, author = {Rietsch, Stefan H. G. and Brunheim, Sascha and Orzada, Stephan and Voelker, Maximilian N. and Maderwald, Stefan and Bitz, Andreas and Gratz, Marcel and Ladd, Mark E. and Quick, Harald H.}, title = {Development and evaluation of a 16-channel receive-only RF coil to improve 7T ultra-high field body MRI with focus on the spine}, series = {Magnetic Resonance in Medicine}, journal = {Magnetic Resonance in Medicine}, number = {Early view}, publisher = {Wiley}, address = {Weinheim}, issn = {1522-2594}, doi = {10.1002/mrm.27731}, year = {2019}, language = {en} } @article{SchoppBritunVoracetal.2019, author = {Schopp, Christoph and Britun, Nikolay and Vorac, Jan and Synek, Petr and Snyders, Rony and Heuermann, Holger}, title = {Thermal and Optical Study on the Frequency Dependence of an Atmospheric Microwave Argon Plasma Jet}, series = {IEEE Transactions on Plasma Science}, volume = {47}, journal = {IEEE Transactions on Plasma Science}, number = {7}, publisher = {IEEE}, address = {New York}, issn = {1939-9375}, pages = {3176 -- 3181}, year = {2019}, language = {en} } @article{SerrorHackHenzeetal.2021, author = {Serror, Martin and Hack, Sacha and Henze, Martin and Schuba, Marko and Wehrle, Klaus}, title = {Challenges and Opportunities in Securing the Industrial Internet of Things}, series = {IEEE Transactions on Industrial Informatics}, volume = {17}, journal = {IEEE Transactions on Industrial Informatics}, number = {5}, publisher = {IEEE}, address = {New York}, issn = {1941-0050}, doi = {10.1109/TII.2020.3023507}, pages = {2985 -- 2996}, year = {2021}, language = {en} } @article{SchmidtForkmannSchultzetal.2019, author = {Schmidt, Katharina and Forkmann, Katarina and Schultz, Heidrun and Gratz, Marcel and Bitz, Andreas and Wiech, Katja and Bingel, Ulrike}, title = {Enhanced Neural Reinstatement for Evoked Facial Pain Compared With Evoked Hand Pain}, series = {The Journal of Pain}, journal = {The Journal of Pain}, number = {In Press, Corrected Proof}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1526-5900}, doi = {10.1016/j.jpain.2019.03.003}, year = {2019}, language = {en} } @article{KoenigWolf2018, author = {K{\"o}nig, Johannes Alexander and Wolf, Martin}, title = {GHOST: An Evaluated Competence Developing Game for Cybersecurity Awareness Training}, series = {International Journal on Advances in Security}, volume = {11}, journal = {International Journal on Advances in Security}, number = {3 \& 4}, publisher = {IARIA Journals}, issn = {1942-2636}, pages = {274 -- 287}, year = {2018}, abstract = {To train end users how to interact with digital systems is indispensable to ensure a strong computer security. 'Competence Developing Game'-based approaches are particularly suitable for this purpose because of their motivation-and simulation-aspects. In this paper the Competence Developing Game 'GHOST' for cybersecurity awareness trainings and its underlying patterns are described. Accordingly, requirements for an 'Competence Developing Game' based training are discussed. Based on these requirements it is shown how a game can fulfill these requirements. A supplementary game interaction design and a corresponding evaluation study is shown. The combination of training requirements and interaction design is used to create a 'Competence Developing Game'-based training concept. A part of these concept is implemented into a playable prototype that serves around one hour of play respectively training time. This prototype is used to perform an evaluation of the game and training aspects of the awareness training. Thereby, the quality of the game aspect and the effectiveness of the training aspect are shown.}, language = {en} } @article{ClaerFerreinSchiffer2019, author = {Claer, Mario and Ferrein, Alexander and Schiffer, Stefan}, title = {Calibration of a Rotating or Revolving Platform with a LiDAR Sensor}, series = {Applied Sciences}, volume = {Volume 9}, journal = {Applied Sciences}, number = {issue 11, 2238}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app9112238}, pages = {18 Seiten}, year = {2019}, 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{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{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{RauschFriesenAltherretal.2018, author = {Rausch, Lea and Friesen, John and Altherr, Lena and Meck, Marvin and Pelz, Peter F.}, title = {A holistic concept to design optimal water supply infrastructures for informal settlements using remote sensing data}, series = {Remote Sensing}, volume = {10}, journal = {Remote Sensing}, number = {2}, publisher = {MDPI}, address = {Basel}, isbn = {2072-4292}, doi = {10.3390/rs10020216}, pages = {1 -- 23}, year = {2018}, abstract = {Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data.}, language = {en} } @article{AltherrEdererPfetschetal.2018, author = {Altherr, Lena and Ederer, Thorsten and Pfetsch, Marc E. and Pelz, Peter F.}, title = {Maschinelles Design eines optimalen Getriebes}, series = {ATZ - Automobiltechnische Zeitschrift}, volume = {120}, journal = {ATZ - Automobiltechnische Zeitschrift}, number = {10}, publisher = {Springer Nature}, address = {Cham}, isbn = {2192-8800}, doi = {10.1007/s35148-018-0131-3}, pages = {72 -- 77}, year = {2018}, abstract = {Nahezu 100.000 denkbare Strukturen kann ein Getriebe bei gleicher Funktion aufweisen - je nach Ganganzahl und gefordertem Freiheitsgrad. Mit dem traditionellen Ansatz bei der Entwicklung, einzelne vielversprechende Systemkonfigurationen manuell zu identifizieren und zu vergleichen, k{\"o}nnen leicht innovative und vor allem kostenminimale L{\"o}sungen {\"u}bersehen werden. Im Rahmen eines Forschungsprojekts hat die TU Darmstadt spezielle Optimierungsmethoden angewendet, um auch bei großen L{\"o}sungsr{\"a}umen zielsicher ein f{\"u}r die individuellen Zielstellungen optimales Layout zu finden.}, language = {de} } @article{AltherrJoggerstLeiseetal.2018, author = {Altherr, Lena and Joggerst, Laura and Leise, Philipp and Pfetsch, Marc E. and Schmitt, Andreas and Wendt, Janine}, title = {On obligations in the development process of resilient systems with algorithmic design methods}, series = {Applied Mechanics and Materials}, volume = {885}, journal = {Applied Mechanics and Materials}, number = {885}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, isbn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.885.240}, pages = {240 -- 252}, year = {2018}, abstract = {Advanced computational methods are needed both for the design of large systems and to compute high accuracy solutions. Such methods are efficient in computation, but the validation of results is very complex, and highly skilled auditors are needed to verify them. We investigate legal questions concerning obligations in the development phase, especially for technical systems developed using advanced methods. In particular, we consider methods of resilient and robust optimization. With these techniques, high performance solutions can be found, despite a high variety of input parameters. However, given the novelty of these methods, it is uncertain whether legal obligations are being met. The aim of this paper is to discuss if and how the choice of a specific computational method affects the developer's product liability. The review of legal obligations in this paper is based on German law and focuses on the requirements that must be met during the design and development process.}, language = {en} } @article{SunAltherrPeietal.2018, author = {Sun, Hui and Altherr, Lena and Pei, Ji and Pelz, Peter F. and Yuan, Shouqi}, title = {Optimal booster station design and operation under uncertain load}, series = {Applied Mechanics and Materials}, volume = {885}, journal = {Applied Mechanics and Materials}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, issn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.885.102}, pages = {102 -- 115}, year = {2018}, abstract = {Given industrial applications, the costs for the operation and maintenance of a pump system typically far exceed its purchase price. For finding an optimal pump configuration which minimizes not only investment, but life-cycle costs, methods like Technical Operations Research which is based on Mixed-Integer Programming can be applied. However, during the planning phase, the designer is often faced with uncertain input data, e.g. future load demands can only be estimated. In this work, we deal with this uncertainty by developing a chance-constrained two-stage (CCTS) stochastic program. The design and operation of a booster station working under uncertain load demand are optimized to minimize total cost including purchase price, operation cost incurred by energy consumption and penalty cost resulting from water shortage. We find optimized system layouts using a sample average approximation (SAA) algorithm, and analyze the results for different risk levels of water shortage. By adjusting the risk level, the costs and performance range of the system can be balanced, and thus the system's resilience can be engineered}, 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{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{AltherrLeisePfetschetal.2018, author = {Altherr, Lena and Leise, Philipp and Pfetsch, Marc E. and Schmitt, Andreas}, title = {Algorithmic design and resilience assessment of energy efficient high-rise water supply systems}, series = {Applied Mechanics and Materials}, volume = {885}, journal = {Applied Mechanics and Materials}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, issn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.885.211}, pages = {211 -- 223}, year = {2018}, abstract = {High-rise water supply systems provide water flow and suitable pressure in all levels of tall buildings. To design such state-of-the-art systems, the consideration of energy efficiency and the anticipation of component failures are mandatory. In this paper, we use Mixed-Integer Nonlinear Programming to compute an optimal placement of pipes and pumps, as well as an optimal control strategy.Moreover, we consider the resilience of the system to pump failures. A resilient system is able to fulfill a predefined minimum functionality even though components fail or are restricted in their normal usage. We present models to measure and optimize the resilience. To demonstrate our approach, we design and analyze an optimal resilient decentralized water supply system inspired by a real-life hotel building.}, language = {en} } @article{AltherrBroetzDietrichetal.2018, author = {Altherr, Lena and Br{\"o}tz, Nicolas and Dietrich, Ingo and Gally, Tristan and Geßner, Felix and Kloberdanz, Hermann and Leise, Philipp and Pelz, Peter Franz and Schlemmer, Pia and Schmitt, Andreas}, title = {Resilience in mechanical engineering - a concept for controlling uncertainty during design, production and usage phase of load-carrying structures}, series = {Applied Mechanics and Materials}, volume = {885}, journal = {Applied Mechanics and Materials}, publisher = {Trans Tech Publications}, address = {B{\"a}ch}, isbn = {1662-7482}, doi = {10.4028/www.scientific.net/AMM.885.187}, pages = {187 -- 198}, year = {2018}, abstract = {Resilience as a concept has found its way into different disciplines to describe the ability of an individual or system to withstand and adapt to changes in its environment. In this paper, we provide an overview of the concept in different communities and extend it to the area of mechanical engineering. Furthermore, we present metrics to measure resilience in technical systems and illustrate them by applying them to load-carrying structures. By giving application examples from the Collaborative Research Centre (CRC) 805, we show how the concept of resilience can be used to control uncertainty during different stages of product life.}, language = {en} } @article{Wolf2000, author = {Wolf, Martin}, title = {Groupware related task design}, series = {ACM SIGGROUP Bulletin}, volume = {21}, journal = {ACM SIGGROUP Bulletin}, number = {2}, issn = {2372-7403}, doi = {10.1145/605660.605662}, pages = {5 -- 8}, year = {2000}, abstract = {his report summarizes the results of a workshop on Groupware related task design which took place at the International Conference on Supporting Group Work Group'99, Arizona, from 14 th to 17 th November 1999. The workshop was addressed to people from different viewpoints, backgrounds, and domains: - Researchers dealing with questions of task analysis and task modeling for Groupware application from an academic point of view. They may contribute modelbased design approaches or theoretically oriented work - Practitioners with experience in the design and everyday use of groupware systems. They might refer to the practical side of the topic: "real" tasks, "real" problems, "real" users, etc.}, language = {en} }