TY - CHAP A1 - Wiegner, Jonas A1 - Volker, Hanno A1 - Mainz, Fabian A1 - Backes, Andreas A1 - Löken, Michael A1 - Hüning, Felix T1 - Wiegand-effect-powered wireless IoT sensor node T2 - Sensoren und Messsysteme 2022 N2 - In this article we describe an Internet-of-Things sensing device with a wireless interface which is powered by the oftenoverlooked harvesting method of the Wiegand effect. The sensor can determine position, temperature or other resistively measurable quantities and can transmit the data via an ultra-low power ultra-wideband (UWB) data transmitter. With this approach we can energy-self-sufficiently acquire, process, and wirelessly transmit data in a pulsed operation. A proof-of-concept system was built up to prove the feasibility of the approach. The energy consumption of the system is analyzed and traced back in detail to the individual components, compared to the generated energy and processed to identify further optimization options. Based on the proof-of-concept, an application demonstrator was developed. Finally, we point out possible use cases. Y1 - 2022 SN - 978-3-8007-5835-7 SP - 255 EP - 260 PB - VDE Verlag GmbH CY - Berlin ER - TY - JOUR A1 - Ferrein, Alexander A1 - Schiffer, Stefan A1 - Booysen, T. A1 - Stopforth, R. T1 - Why it is harder to run RoboCup in South Africa: Experiences from German South African collaborations JF - International Journal of Advanced Robotic Systems N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1177/1729881416662789 SN - 1729-8806 VL - 13 IS - 5 SP - 1 EP - 13 ER - TY - CHAP A1 - Amir, Malik A1 - Bauckhage, Christian A1 - Chircu, Alina A1 - Czarnecki, Christian A1 - Knopf, Christian A1 - Piatkowski, Nico A1 - Sultanow, Eldar T1 - What can we expect from quantum (digital) twins? N2 - Digital twins enable the modeling and simulation of real-world entities (objects, processes or systems), resulting in improvements in the associated value chains. The emerging field of quantum computing holds tremendous promise for evolving this virtualization towards Quantum (Digital) Twins (QDT) and ultimately Quantum Twins (QT). The quantum (digital) twin concept is not a contradiction in terms - but instead describes a hybrid approach that can be implemented using the technologies available today by combining classical computing and digital twin concepts with quantum processing. This paper presents the status quo of research and practice on quantum (digital) twins. It also discuses their potential to create competitive advantage through real-time simulation of highly complex, interconnected entities that helps companies better address changes in their environment and differentiate their products and services. KW - Artificial Intelligence KW - Digital Twin Evolution KW - Machine Learning KW - Quantum Computing KW - Quantum Machine Learning Y1 - 2022 N1 - 17. Internationale Tagung Wirtschaftsinformatik, 21. – 23. Februar 2022, Nürnberg (online) SP - 1 EP - 14 PB - AIS Electronic Library (AISeL) ER - TY - JOUR A1 - Hartung, Frank A1 - Husoy, J. H. T1 - Wavelet and subband coding of images - A comparative study / Hartung, F. ; Husoy, J. H. JF - 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 Y1 - 1993 SN - 081941283X N1 - SPIE proceedings series ; 2034 ; Society of Photo-Optical Instrumentation Engineers ; Conference ; (1993.07.15-16 : ; San Diego, Calif.) SP - 242 EP - 253 PB - SPIE CY - Bellingham, Wash. ER - TY - JOUR A1 - Elsen, Ingo A1 - Kraiss, Karl-Friedrich A1 - Krumbiegel, Dirk A1 - Walter, Peter A1 - Wickel, Jochen T1 - Visual information retrieval for 3D product identification: a midterm report JF - KI - Künstliche Intelligenz Y1 - 1999 SN - 1610-1987 SN - 0933-1875 VL - 13 IS - 1 SP - 64 EP - 67 PB - Springer CY - Berlin ER - TY - CHAP A1 - Galdi, Chiara A1 - Hartung, Frank A1 - Dugelay, Jean-Luc T1 - Videos versus still images: Asymmetric sensor pattern noise comparison on mobile phones T2 - Electronic Imaging N2 - Nowadays, the most employed devices for recoding videos or capturing images are undoubtedly the smartphones. Our work investigates the application of source camera identification on mobile phones. We present a dataset entirely collected by mobile phones. The dataset contains both still images and videos collected by 67 different smartphones. Part of the images consists in photos of uniform backgrounds, especially collected for the computation of the RSPN. Identifying the source camera given a video is particularly challenging due to the strong video compression. The experiments reported in this paper, show the large variation in performance when testing an highly accurate technique on still images and videos. KW - Image Forensics KW - Mobile Phones KW - Image Database Y1 - 2017 U6 - http://dx.doi.org/10.2352/ISSN.2470-1173.2017.7.MWSF-331 SN - 2470-1173 N1 - IS&T International Symposium on Electronic Imaging 2017 Media Watermarking, Security, and Forensics 2017 SP - 100 EP - 103 PB - Society for Imaging Science and Technology CY - Springfield, Virginia ER - TY - JOUR A1 - Theysohn, Jens M. A1 - Kraff, Oliver A1 - Eilers, Kristina A1 - Andrade, Dorian A1 - Gerwig, Marcus A1 - Timmann, Dagmar A1 - Schmitt, Franz A1 - Ladd, Mark E. A1 - Ladd, Susanne C. A1 - Bitz, Andreas T1 - Vestibular effects of a 7 Tesla MRI examination compared to 1.5 T and 0 T in healthy volunteers JF - PLoS one N2 - 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. Y1 - 2014 U6 - http://dx.doi.org/10.1371/journal.pone.0092104 SN - 1932-6203 VL - 9 IS - 3 PB - PLOS CY - San Francisco ER - TY - JOUR A1 - Heuermann, Holger T1 - Verringerung des Phasenrauschens von Oszillatoren durch Dual-Mode-Resonatoren JF - HF-Report. 20 (2006), H. 5-6 Y1 - 2006 SN - 1431-827X SP - 43 EP - 48 ER - TY - JOUR A1 - Heuermann, Holger A1 - Ibrahim, Irfan A1 - Hillebrand, J. T1 - Vector-Signal-Generator with Two ¿¿-PLL's / Ibrahim, I. ; Hillebrand, J. ; Heuermann, H. JF - European Conference on Wireless Technologies, 2007. ECWT 2007 ; 8 - 10 October 2007 Munich, Germany Y1 - 2007 SN - 978-2-87487-003-3 SP - 1 EP - 4 ER - TY - JOUR A1 - Yazdanbakhsh, Pedram A1 - Solbach, Klaus A1 - Bitz, Andreas T1 - Variable power combiner for RF mode shimming in 7-T MR imaging JF - IEEE Transaction on Biomedical Engineering N2 - 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. Y1 - 2012 U6 - http://dx.doi.org/10.1109/TBME.2012.2205926 SN - 1558-2531 VL - 59 IS - 9 SP - 2549 EP - 2557 PB - IEEE CY - New York ER -