@inproceedings{TischbeinKeanVertgewalletal.2023, author = {Tischbein, Franziska and Kean, Kilian and Vertgewall, Chris Martin and Ulbig, Andreas and Altherr, Lena}, title = {Determination of the topology of low-voltage distribution grids using cluster methods}, series = {27th International Conference on Electricity Distribution (CIRED 2023)}, booktitle = {27th International Conference on Electricity Distribution (CIRED 2023)}, publisher = {IEEE}, isbn = {978-1-83953-855-1}, doi = {10.1049/icp.2023.0478}, pages = {1 -- 5}, year = {2023}, abstract = {Due to the decarbonization of the energy sector, the electric distribution grids are undergoing a major transformation, which is expected to increase the load on the operating resources due to new electrical loads and distributed energy resources. Therefore, grid operators need to gradually move to active grid management in order to ensure safe and reliable grid operation. However, this requires knowledge of key grid variables, such as node voltages, which is why the mass integration of measurement technology (smart meters) is necessary. Another problem is the fact that a large part of the topology of the distribution grids is not sufficiently digitized and models are partly faulty, which means that active grid operation management today has to be carried out largely blindly. It is therefore part of current research to develop methods for determining unknown grid topologies based on measurement data. In this paper, different clustering algorithms are presented and their performance of topology detection of low voltage grids is compared. Furthermore, the influence of measurement uncertainties is investigated in the form of a sensitivity analysis.}, language = {en} } @inproceedings{ThomeCzarneckiAuthetal.2017, author = {Thom{\´e}, Tristan Eberhard and Czarnecki, Christian and Auth, Gunnar and Bensberg, Frank}, title = {Erweiterung des Referenzprozessmodells eTOM um die Anforderungen des deutschen IT-Sicherheitsgesetzes}, series = {Prozesse, Technologie, Anwendungen, Systeme und Management 2017. Angewandte Forschung in der Wirtschaftsinformatik}, booktitle = {Prozesse, Technologie, Anwendungen, Systeme und Management 2017. Angewandte Forschung in der Wirtschaftsinformatik}, editor = {Barton, Thomas and Herrmann, Frank and Meister, Vera G. and M{\"u}ller, Christian and Seel, Christian}, publisher = {mana-Buch}, address = {Heide}, isbn = {978-3-944330-56-3}, pages = {51 -- 60}, year = {2017}, abstract = {Kritische Infrastrukturen sind prim{\"a}re Ziele krimineller Hacker. Der Deutsche Bundestag reagierte darauf am 25. Juli 2015 mit einem Gesetz zur Verbesserung der Sicherheit von ITSystemen, dem IT-Sicherheitsgesetz. Dies verlangt von Betreibern kritischer Infrastrukturen, angemessene Mindeststandards f{\"u}r organisatorische und technische Sicherheit zu implementieren, um den Betrieb und die Verf{\"u}gbarkeit dieser Infrastruktur zu gew{\"a}hrleisten. Telekommunikationsunternehmen sind einerseits von diesem Gesetz in besonderem Maße betroffen und verf{\"u}gen andererseits mit dem Rahmenwerk enhanced Telecom Operations Map (eTOM) {\"u}ber ein international anerkanntes Referenzmodell zur Gestaltung von Gesch{\"a}ftsprozessen in dieser Branche. Da s{\"a}mtliche Telekommunikationsunternehmen in Deutschland verpflichtet sind, das Gesetz innerhalb eines bestimmten Zeitrahmens zu implementieren, pr{\"a}sentiert dieser Beitrag einen Vorschlag zur Erweiterung von eTOM um die relevanten Anforderungen des deutschen IT-Sicherheitsgesetzes.}, language = {de} } @techreport{ThomaLaarmannMerkensetal.2020, author = {Thoma, Andreas and Laarmann, Lukas and Merkens, Torsten and Franzke, Till and M{\"o}hren, Felix and Buttermann, Lilly and van der Weem, Dirk and Fischer, Maximilian and Misch, Philipp and B{\"o}hme, Mirijam and R{\"o}th, Thilo and Hebel, Christoph and Ritz, Thomas and Franke, Marina and Braun, Carsten}, title = {Entwicklung eines intermodalen Mobilit{\"a}tskonzeptes f{\"u}r die Pilotregion NRW/Rhein-Maas Euregio und Schaffung voller Kundenakzeptanz durch Transfer von Standards aus dem PKW-Bereich auf ein Flugtaxi : Schlussbericht : Projektakronym: SkyCab (Kategorie B) : Laufzeit in Monaten: 6 : Hauptthema: Kategorie B: Innovative Ideen mit Bezug zu UAS/Flugtaxis}, publisher = {FH Aachen}, address = {Aachen}, pages = {97 Seiten}, year = {2020}, language = {de} } @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{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{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} } @inproceedings{StoebeHoefkenSchubaetal.2013, author = {St{\"o}be, Rolf and H{\"o}fken, Hans-Wilhelm and Schuba, Marko and Breuer, Michael}, title = {Artificial ageing of mobile devices using a simulated GSM/GPRS network}, series = {Eighth International Conference on Availability, Reliability and Security (ARES) : 2-6 Sept. 2013, Regensburg}, booktitle = {Eighth International Conference on Availability, Reliability and Security (ARES) : 2-6 Sept. 2013, Regensburg}, publisher = {IEEE}, pages = {493 -- 497}, year = {2013}, language = {en} } @inproceedings{StopforthFerreinSteinbauer2015, author = {Stopforth, Riaan and Ferrein, Alexander and Steinbauer, Gerald}, title = {Europe and South African collaboration on the Mechatronics and Robotics systems as part of the SA Robotics Center}, series = {ICRA 2015 Developing Countries Forum}, booktitle = {ICRA 2015 Developing Countries Forum}, pages = {3 S.}, year = {2015}, abstract = {Mechatronics consist of the integration of mechanical engineering, electronic integration and computer science/ engineering. These broad fields are essential for robotic systems, yet it makes it difficult for the researchers to specialize and be experts in all these fields. Collaboration between researchers allow for the integration of experience and specialization, to allow optimized systems. Collaboration between the European countries and South Africa is critical, as each country has different resources available, which the other countries might not have. Applications with the need for approval of any restrictions, can also be obtained easier in some countries compared to others, thus preventing the delays of research. Some problems that have been experienced are discussed, with the Robotics Center of South Africa as a possible solution.}, language = {en} } @inproceedings{StopforthDavrajhFerrein2017, author = {Stopforth, Riaan and Davrajh, Shaniel and Ferrein, Alexander}, title = {South African robotics entity for a collaboration initiative}, series = {Pattern Recognition Association of South Africa and Robotics and Mechatronics International Conference (PRASA-RobMech), 2016}, booktitle = {Pattern Recognition Association of South Africa and Robotics and Mechatronics International Conference (PRASA-RobMech), 2016}, publisher = {IEEE}, isbn = {978-1-5090-3335-5}, doi = {10.1109/RoboMech.2016.7813144}, pages = {1 -- 6}, year = {2017}, language = {en} } @inproceedings{StopforthDavrajhFerrein2017, author = {Stopforth, Riaan and Davrajh, Shaniel and Ferrein, Alexander}, title = {Design considerations of the duo fugam dual rotor UAV}, series = {2017 Pattern Recognition Association of South Africa and Robotics and Mechatronics (PRASA-RobMech)}, booktitle = {2017 Pattern Recognition Association of South Africa and Robotics and Mechatronics (PRASA-RobMech)}, isbn = {978-1-5386-2314-5}, doi = {10.1109/RoboMech.2017.8261115}, pages = {7 -- 13}, year = {2017}, language = {en} }