@inproceedings{BaeumlHaumerKapelleretal., author = {B{\"a}uml, T. and Haumer, Anton and Kapeller, Hansj{\"o}rg and Starzinger, J. and Farzi, P.}, title = {Impact of inverter pulse inhibition on the high-voltage supply system of an electric vehicle — A simulative approach}, series = {2011 IEEE Vehicle Power and Propulsion Conference (VPPC 2011) : Powering sustainable transportation ; Chicago, Illinois, USA, 06. - 09.09.2011}, booktitle = {2011 IEEE Vehicle Power and Propulsion Conference (VPPC 2011) : Powering sustainable transportation ; Chicago, Illinois, USA, 06. - 09.09.2011}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-61284-248-6}, doi = {10.1109/VPPC.2011.6043159}, pages = {1 -- 5}, abstract = {This paper deals with a simulative approach for investigating the impact of inverter pulse inhibition during field weakening operation of permanent magnet synchronous machines and asynchronous induction machines. The modelling and simulation language Modelica is used to design models for the vehicle, the electric machine and the inverter in different abstraction levels. It is shown that when using a permanent magnet synchronous machine, a sudden breakdown of the field weakening current causes induction of high voltages in the stator windings. Hence, the electric system of the vehicle has to be protected against the resulting high currents. Furthermore precautions have to be taken to avoid dangerous driving conditions because of high braking torques in an inverter fault operation mode. In the case of the asynchronous induction machine an inverter pulse inhibition poses no big problem, neither for the electric system of the vehicle, nor the driver.}, language = {en} } @inproceedings{HolthausHagedornKlanketal., author = {Holthaus, Carsten and Hagedorn, Oliver and Klank, Michael and Shamonin (Chamonine), Mikhail and Trifonov, A. and D{\"o}tsch, Horst}, title = {Preparation and Characterization of Sensitive Magnetic Garnet Films for MOI Applications}, series = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, booktitle = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, publisher = {Kluwer}, address = {Dodrecht}, doi = {10.1007/978-94-007-1007-8_42}, pages = {329 -- 336}, abstract = {Magnetic garnet films prepared by liquid phase epitaxy on paramagnetic substrates of gadolinium gallium garnet are currently used for the imaging of magnetic field distributions. This application is based on the Faraday rotation which can be strongly enhanced by bismuth incorporation. For gray scale imaging the plane of the sensor film should be an easy plane of magnetization so that no domains nucleate. However, incorporation of bismuth induces a strong positive uniaxial anisotropy perpendicular to the film plane, especially if films of [111] orientation are used. To counteract this unwanted behavior neodymium and/or praseodymium are substituted in addition to bismuth. These two elements cause a very strong negative anisotropy. This is tested experimentally by growing series of garnet films with gradually changing composition and growth parameters.}, language = {en} } @article{BodnarukBrunhuberKalitaetal., author = {Bodnaruk, Andrii V. and Brunhuber, Alexander and Kalita, Viktor M. and Kulyk, Mykola M. and Snarskii, Andrei A. and Lozenko, Albert F. and Ryabchenko, Sergey M. and Shamonin (Chamonine), Mikhail}, title = {Temperature-dependent magnetic properties of a magnetoactive elastomer: Immobilization of the soft-magnetic filler}, series = {Journal of Applied Physics}, volume = {123}, journal = {Journal of Applied Physics}, number = {11}, publisher = {AIP Publishing}, doi = {10.1063/1.5023891}, abstract = {The magnetic properties of a magnetoactive elastomer (MAE) filled with mu m-sized soft-magnetic iron particles have been experimentally studied in the temperature range between 150 K and 310 K. By changing the temperature, the elastic modulus of the elastomer matrix was modified, and it was possible to obtain magnetization curves for an invariable arrangement of particles in the sample and in the case when the particles were able to change their position within the MAE under the influence of magnetic forces. At low (less than 220 K) temperatures, when the matrix becomes rigid, the magnetization of the MAE does not show a hysteresis behavior, and it is characterized by a negative value of the Rayleigh constant. At room temperature, when the polymer matrix is compliant, a magnetic hysteresis exists where the dependence of the differential magnetic susceptibility on the magnetic field exhibits local maxima. The appearance of these maxima is explained by the elastic resistance of the matrix to the displacement of particles under the action of magnetic forces.}, language = {en} } @inproceedings{JungreuthmayerBaumlWinteretal., author = {Jungreuthmayer, C. and Bauml, T. and Winter, O. and Ganchev, M. and Kapeller, Hansj{\"o}rg and Haumer, Anton and Kral, Christian}, title = {Heat and fluid flow analysis of an internal permanent magnet synchronous machine by means of computational fluid dynamics}, series = {2011 IEEE International Electric Machines \& Drives Conference (IEMDC 2011) ; Niagara Falls, Ontario, Canada, 15 - 18 May 2011}, booktitle = {2011 IEEE International Electric Machines \& Drives Conference (IEMDC 2011) ; Niagara Falls, Ontario, Canada, 15 - 18 May 2011}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4577-0060-6}, doi = {10.1109/IEMDC.2011.5994651}, pages = {515 -- 520}, abstract = {This paper presents a comprehensive computational fluid (CFD) model of a radial flux permanent magnet synchronous machine with interior magnets. In the CFD model the water jacket cooling and a simplified model of the topology of the distributed stator winding are considered. The heat sources of the CFD model are determined from a finite element analysis of the machine. The numerically determined temperature distributions of the machine are compared with measurement results from sensors located both in the stator and rotor. The particular focus of this paper is the analysis of the temperatures and the heat flow in the air gap and from the stator winding head and the rotor to the inner air.}, language = {en} } @article{ShamoninChamonineKlankHagedornetal., author = {Shamonin (Chamonine), Mikhail and Klank, Michael and Hagedorn, Oliver and D{\"o}tsch, Horst}, title = {Magneto-optical visualization of metal-loss defects in a ferromagnetic plate: experimental verification of theoretical modeling}, series = {Applied optics}, volume = {40}, journal = {Applied optics}, number = {19}, publisher = {Optica Publishing Group}, doi = {10.1364/ao.40.003182}, pages = {3182 -- 3189}, abstract = {Rare-earth iron garnet films with in-plane magnetic anisotropy grown on [111]-oriented substrates are promising for the visualization of magnetic leakage fields in nondestructive evaluation. Such magneto-optical films have to be specifically engineered, and we give an example of this technology. To assess the validity and accuracy of finite-element calculations of a magnetization assembly combined with the physical modeling of the image formation, comparisons between calculated and experimentally obtained magneto-optical images of metal-loss defects have been made. A convincing quantitative agreement is demonstrated. It is shown that both physical and computer modeling techniques allow for a predictive engineering design of the prospective applications and provide greater insight into the method.}, language = {en} } @article{BodnarukAndriiVBrunhuberetal., author = {Bodnaruk, and Andrii V., and Brunhuber, Alexander and Kalita, Viktor M. and Kulyk, Mykola M. and Kurzweil, Peter and Snarskii, Andrei A. and Lozenko, Albert F. and Ryabchenko, Sergey M. and Shamonin (Chamonine), Mikhail}, title = {Magnetic anisotropy in magnetoactive elastomers, enabled by matrix elasticity}, series = {Polymer}, volume = {162}, journal = {Polymer}, number = {January}, publisher = {Elsevier}, doi = {10.1016/j.polymer.2018.12.027}, pages = {63 -- 72}, abstract = {Polydimethylsiloxane based magnetoactive elastomers demonstrate above the melting transition range (e.g. at room temperature) an induced uniaxial magnetic anisotropy, which grows with increasing magnetic field. By freezing a material down to 150 K, displaced iron microparticles are immobilized, so that the magnetic anisotropy can be measured. Magnetic anisotropy "constant" is a consequence of particle displacements and a characteristic of the energy of internal deformations in the polymer matrix. The maximum anisotropy constant of the filling is at least one order of magnitude larger than the shear modulus of the pure elastomer (matrix). In a magnetic field, the gain in the rigidity of the composite material is attributed to the magnetomechanical coupling, which is in turn a source of anisotropy. The concept of effective magnetic field felt by the magnetization allows one to explain the magnetization curve at room temperature from low-temperature measurements. The results can be useful for developing vibration absorbers and isolators.}, language = {en} } @inproceedings{DoetschKlankHagedornetal., author = {D{\"o}tsch, Horst and Klank, Michael and Hagedorn, Oliver and Holthaus, Carsten and Shamonin (Chamonine), Mikhail and Trifonov, A.}, title = {Optimization of Magnetic Garnet Films for Magneto-Optical Imaging of Magnetic Field Distributions}, series = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, booktitle = {Magneto-Optical Imaging. Proceedings of the NATO Advanced Research Workshop on Magneto-Optical Imaging, {\O}ystese, Norway, 28 - 30 August 2003}, publisher = {KLuwer}, address = {Dodrecht}, doi = {10.1007/978-94-007-1007-8_39}, pages = {301 -- 309}, abstract = {Rare-earth iron garnet films are currently applied for magneto-optical imaging of magnetic field distributions. The physical properties of the films can be controlled by the chemical composition, the growth conditions and the crystallographic orientation. The sensor properties must be optimized according to the application desired. A new optimization method is introduced based on the swing of the photoresponse. An application example is presented. Furthermore, the sensitivity can be strongly enhanced using specific crystallographic orientations which induce an easy plane of magnetization being tilted with respect to the film plane. Experimental results of a [112] oriented garnet film are in good agreement with calculations. The influence of the cubic anisotropy on the sensor performance is discussed. Finally, it is shown that also domain films can be applied for magneto-optical imaging.}, language = {en} } @article{KlankHagedornHolthausetal., author = {Klank, Michael and Hagedorn, Oliver and Holthaus, Carsten and Shamonin (Chamonine), Mikhail and D{\"o}tsch, Horst}, title = {Characterization and optimization of magnetic garnet films for magneto-optical visualization of magnetic field distributions}, series = {NDT \& E International}, volume = {36}, journal = {NDT \& E International}, number = {6}, publisher = {Elsevier}, doi = {10.1016/S0963-8695(03)00012-4}, pages = {375 -- 381}, abstract = {Rare-earth iron garnet films with in-plane anisotropy grown on (111)-oriented substrates can be used as magneto-optical indicator films for visualization of magnetic leakage fields in nondestructive evaluation. The influence of Faraday rotation, Faraday ellipticity, absorption and film thickness on the performance of a magneto-optical indicator film is investigated. A new optimization method is introduced and compared with the method of contrast optimization. The theory is experimentally verified and an application example is presented.}, language = {en} } @article{KrieglKravanjaHribaretal., author = {Kriegl, Raphael and Kravanja, Gaia and Hribar, Luka and Čoga, Lucija and Drevenšek-Olenik, Irena and Jezeršek, Matija and Kalin, Mitjan and Shamonin (Chamonine), Mikhail}, title = {Microstructured Magnetoactive Elastomers for Switchable Wettability}, series = {Polymers}, volume = {14}, journal = {Polymers}, number = {18}, publisher = {MDPI}, doi = {10.3390/polym14183883}, pages = {1 -- 21}, abstract = {We demonstrate the control of wettability of non-structured and microstructured magnetoactive elastomers (MAEs) by magnetic field. The synthesized composite materials have a concentration of carbonyl iron particles of 75 wt.\% (≈27 vol.\%) and three different stiffnesses of the elastomer matrix. A new method of fabrication of MAE coatings on plastic substrates is presented, which allows one to enhance the response of the apparent contact angle to the magnetic field by exposing the particle-enriched side of MAEs to water. A magnetic field is not applied during crosslinking. The highest variation of the contact angle from (113 ± 1)° in zero field up to (156 ± 2)° at about 400 mT is achieved in the MAE sample with the softest matrix. Several lamellar and pillared MAE structures are fabricated by laser micromachining. The lateral dimension of surface structures is about 50 µm and the depth varies between 3 µm and 60 µm. A systematic investigation of the effects of parameters of laser processing (laser power and the number of passages of the laser beam) on the wetting behavior of these structures in the absence and presence of a magnetic field is performed. In particular, strong anisotropy of the wetting behavior of lamellar structures is observed. The results are qualitatively discussed in the framework of the Wenzel and Cassie-Baxter models. Finally, directions of further research on magnetically controlled wettability of microstructured MAE surfaces are outlined. The obtained results may be useful for the development of magnetically controlled smart surfaces for droplet-based microfluidics.}, language = {en} } @article{ShamoninChamonineBeukerRosenetal., author = {Shamonin (Chamonine), Mikhail and Beuker, T. and Rosen, P. and Klank, Michael and Hagedorn, Oliver and D{\"o}tsch, Horst}, title = {Feasibility of magneto-optic flaw visualization using thin garnet films}, series = {NDT \& E International}, volume = {33}, journal = {NDT \& E International}, number = {8}, publisher = {Elsevier}, doi = {10.1016/s0963-8695(00)00028-1}, pages = {547 -- 553}, abstract = {We investigate the feasibility of using rare-earth iron garnet films grown on (111)-oriented substrates as magneto-optic indicator films for the visualization of magnetic leakage fields in non-destructive evaluation. In most cases the leakage field of the defect has a strong component in the film plane. The influence of this in-plane dc magnetic field on the image formation is investigated. It is shown that the presence of a strong in-plane magnetic field allows one to extend the dynamic range of the out-of-plane field imposed by the uniaxial anisotropy field HA. On the other hand, an in-plane field reduces the sensitivity. The guidelines for selecting parameters of magneto-optic indicator films are given.}, language = {en} } @article{KlankHagedornShamoninChamonineetal., author = {Klank, Michael and Hagedorn, Oliver and Shamonin (Chamonine), Mikhail and Rosen, H. and D{\"o}tsch, Horst}, title = {Sensitive magneto-optical sensors for visualization of magnetic fields using garnet films of specific orientations}, series = {Journal of Applied Physics}, volume = {92}, journal = {Journal of Applied Physics}, publisher = {AIP}, doi = {10.1063/1.1516839}, abstract = {Garnet films of high Faraday rotation are applied as magneto-optical sensors to visualize the spatial distribution of magnetic fields. Using specific orientations, the induced anisotropy can generate an easy plane of magnetization which is inclined with respect to the film plane. If the magnetization lies in this plane a very high sensitivity can be achieved. The dependence of the geometrical orientation of the easy plane on the growth direction is calculated and the sensitivity and dynamic range are derived. Experimental results of a [112] oriented garnet film are in good agreement with calculations.}, language = {en} } @article{ZimmermannBoehmBeckerTIetal., author = {Zimmermann, Klaus and B{\"o}hm, Valter and Becker T.I., and Chavez Vega, Jhohan Harvey and Kaufhold, Tobias and Monkman, Gareth J. and Sindersberger, Dirk and Diermeier, Andreas and Prem, Nina}, title = {Mechanical Characterization of the Field-Dependent Properties of Magnetoactive Polymers and Integrated Electrets for their Application in Soft Robotics}, series = {International Scientific Journal "Problems of Mechanics"}, volume = {69}, journal = {International Scientific Journal "Problems of Mechanics"}, number = {4}, issn = {1512-0740}, language = {en} } @inproceedings{DoetschHolthausTrifonovetal., author = {D{\"o}tsch, Horst and Holthaus, Carsten and Trifonov, A. and Klank, Michael and Hagedorn, Oliver and Shamonin (Chamonine), Mikhail and Sch{\"u}tzmann, J.}, title = {Application of Magnetic Garnet Films for Magnetooptical Imaging of Magnetic Field Distributions}, series = {MRS Online Proceedings Library}, booktitle = {MRS Online Proceedings Library}, publisher = {Springer}, doi = {10.1557/PROC-834-J6.1}, pages = {18 -- 29}, abstract = {Rare-earth iron garnet films of high quality can be grown by liquid phase epitaxy on paramagnetic substrates of gadolinium galliumgarnet. Such films are currently used for imaging of the spatial distribution of magnetic fields. This application is based on the Faraday rotation which can strongly be enhanced by bismuth incorporation. The physical properties of the films can be controlled by the chemical composition, the growth conditions and the crystallographic orientation. The sensor properties like sensitivity, dynamic range, signal linearity and unambiguity must be optimized according to the application desired. These properties, however, are not independent of each other. In addition, they strongly depend on the optical wavelength. Thus, it is necessary to find compromises. The influence of Faraday rotation, Faraday ellipticity, optical absorption, magnetic anisotropies and film thickness on the performance of a magnetooptical indicator film is investigated. Based on the swing of the photoresponse, a new optimization process is introduced. The process is experimentally verified and application examples are demonstrated. Furthermore, two methods are presented to enhance the sensitivity of magnetooptical sensors. Using specific crystallographic orientations, an easy plane of magnetization can be induced which is inclined with respect to the film plane. If the magnetization lies in this plane a very high sensitivity is achieved. The dependence of the geometrical orientation of the easy plane on the growth direction is calculated and the sensitivity and dynamic range are derived. Experimental results of a [112] oriented garnet film are in good agreement with calculations. Garnet films which are magnetized along the film normal due to a strong induced uniaxial anisotropy support magnetic domains. If the collapse field perpendicular to the film plane is small, such films can be used as very sensitive indicator films. Such films are easier to prepare than sensitive in-plane films. However, the spatial resolution is limited by the size of the domains. This disadvantage can be avoided by applying a bias field in the film plane. Directly at the in-plane collapse field the sensor film is in-plane magnetized yielding high spatial resolution at still high sensitivity. The variation of magnetooptical images with in-plane induction is demonstrated. Experimental results are in agreement with calculations.}, language = {en} } @article{LangMonkman, author = {Lang, Alexander and Monkman, Gareth J.}, title = {An analysis of the electrical capacitance between two conducting spheres}, series = {Journal of Electrostatics}, volume = {108}, journal = {Journal of Electrostatics}, publisher = {Elsevier}, doi = {10.1016/j.elstat.2020.103518}, abstract = {Many modern composites consist of dielectric polymer matrices containing embedded spherical particles. These particles can be electrically conducting and often have magnetic properties. In order to accurately model and simulate such materials, precise calculation of the electrical capacitance between identically sized spheres is required. This is of particular relevance at microscopic dimensions where many smart material-based micro devices are concerned. This may appear trivial for a small number of particles. However, many methods or their analysis appear to be questionable or not applicable at reduced dimensions. In this work, the various methods of analysis are scrutinized before being compared with both simulation and direct measurements. It is surprising to note that of the many works investigated only 3 are in close agreement with both simulation and measurement. Graphical abstract This paper deals with the precise calculation of the electrical capacitance between two conducting spheres of equal, or near equal size.The calculations have been verified by both experimental measurements and simulation. Algorithms in MatLab (Octave) format have been included in the supporting information.}, language = {en} } @inproceedings{LegrandBoeseErmertetal., author = {Legrand, Virginie and B{\"o}se, Holger and Ermert, Helmut and Freimuth, Herbert and Baumann, Michael and Egersd{\"o}rfer, Stefan and Meier, Alexander and Dragoi, Daniel}, title = {Technologien f{\"u}r haptische Systeme in der Informations{\"u}bertragung}, series = {IAFW Tagung - Lengenfeld, Mai 2003}, booktitle = {IAFW Tagung - Lengenfeld, Mai 2003}, language = {de} } @inproceedings{ReindlLangerMeieretal., author = {Reindl, Andrea and Langer, Tobias and Meier, Hans and Niemetz, Michael}, title = {Comparative Reliability Analysis for Single and Dual CAN (FD) Systems}, series = {27th 2022 International Conference on Applied Electronics (AE): 6-7 September 2022, Pilsen, Czech Republic}, booktitle = {27th 2022 International Conference on Applied Electronics (AE): 6-7 September 2022, Pilsen, Czech Republic}, publisher = {IEEE}, isbn = {9781665494816}, doi = {10.1109/AE54730.2022.9920078}, pages = {1 -- 6}, abstract = {Modern cyber-physical systems, such as autonomous vehicles, advanced driver assistance systems, automation systems and battery management systems, result in extended communication requirements regarding the reliability and the availability. The Controller Area Network (CAN) is a broadcast-based protocol which is still used as a standard for serial communication between individual microcontrollers due to its reliability and low power consumption. In addition, it provides mechanisms for detecting transmission errors and retransmitting messages in the event of an error. The enhancement CAN Flexible Data-Rate (CAN FD) offers increased data rates and transmission rates in order to meet the data throughput requirements. In this paper, the mechanisms for reliable data transmission in a CAN FD network are analyzed. To improve reliability, a second identical CAN-FD network is added to the system, using the additional CAN interface already available on common microcontrollers. The redundant communication network is examined in terms of failure rates and the mean time to failure. The reliability over the operation time is calculated for the single and the redundant version of the CAN FD network using the failure rate limits of the ASIL levels.}, language = {en} } @article{Unold, author = {Unold, Heiko}, title = {„Analog Discovery 2" mobiles Praktikum OTH Regensburg}, series = {strategie digital. Magazin f{\"u}r Hochschulstrategien im digitalen Zeitalter}, journal = {strategie digital. Magazin f{\"u}r Hochschulstrategien im digitalen Zeitalter}, number = {Ausgabe \#05: Kooperative Curriculumentwicklung}, editor = {Hochschulforum Digitalisierung,}, issn = {2750-0993}, pages = {1}, abstract = {Allen Studierenden wird zu Beginn des zweiten Semesters ein elektronisches Experimentierset mit einem Analog Discovery als „mobiles Praktikum" f{\"u}r die gesamte Dauer des Studiums ausgeliehen. Im Rahmen der Lehrinnovationsprofessur (LIP) wird Material f{\"u}r m{\"o}glichst viele verschiedene Module des Studiengangs entwickelt, um Fachwissen praktisch erfahrbar zu machen und gleichzeitig die Module inhaltlich zu verkn{\"u}pfen.}, subject = {Elektroniktechnologie}, language = {de} } @article{LiLange, author = {Li, Liwen and Lange, Klaus W.}, title = {Planning Principles for Integrating Community Empowerment into Zero-Net Carbon Transformation}, series = {smart cities}, volume = {2023}, journal = {smart cities}, number = {6}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/smartcities6010006}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-57765}, pages = {100 -- 122}, abstract = {The adoption of the UN 2030 Agenda and the Sustainable Development Goals is a landmark in international sustainability politics. For example, Europe has set ambitious targets to achieve 100 climate-neutral and smart cities by 2030. However, numerous case studies from different countries have found that accelerating the transition to net-zero carbon emissions is easily hampered by the lack of a coherent systems framework, and that implementation gaps remain at the community level. These barriers are often due to a lack of an adequate end-user (i.e., household) input and early planning participation. This work therefore aims to improve on conventional planning methods that do not reflect innovative technologies with uncertainty and may not be applicable due to the lack of community empowerment, which is a dynamic learning and intervention opportunity for end-users at different planning stages (i.e., outreach, survey, planning, implementation, management, and maintenance). Using the lessons learned from participatory action research, whereby the author was involved as a project director throughout the planning and design process, we identified a six-step cycle principle. The steps are (1) collective action commitments, (2) local values and resource identification, (3) carbon footprint inventory, (4) optimized integration of environment, economy, and energy action plans, (5) Flexible strategic energy system plans, and (6) digital performance monitoring. Ultimately, the outcomes provide application support for policymakers and planners and stimulate community engagement to contribute to the achievement of zero net carbon emissions.}, language = {en} } @inproceedings{BockMottokKoehler, author = {Bock, T. and Mottok, J{\"u}rgen and K{\"o}hler, Thorsten}, title = {A gesture-based human-machine interface using stereoscopic depth images}, series = {2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg}, booktitle = {2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg}, editor = {Mottok, J{\"u}rgen and Ziemann, Olaf}, publisher = {Shaker}, address = {Aachen}, pages = {166 -- 169}, abstract = {Reasonable integration of gesture-based automotive HMI-functionality offers potential safety benefits by reducing driver distractions and glance times to operate tertiary in-car devices. Stereo camera systems are a well investigated choice to perform the task of generating depth data for spatial gesture recognition. This paper describes the functionality of our stereo vision software, which is intended for application in a target system based on CMOS wafer-level cameras. The retrieved point cloud data was passed to a gesture-based sample application.}, language = {en} } @inproceedings{MaierMottok, author = {Maier, Robert and Mottok, J{\"u}rgen}, title = {BayesianSafety - an Open-Source Package for Causality-Guided, Multi-Model Safety Analysis}, series = {Computer Safety, Reliability, and Security, 41st International Conference (SAFECOMP 2022): Munich, Germany, September 6-9, 2022, Proceedings}, booktitle = {Computer Safety, Reliability, and Security, 41st International Conference (SAFECOMP 2022): Munich, Germany, September 6-9, 2022, Proceedings}, editor = {Trapp, Mario and Saglietti, Francesca and Spisl{\"a}nder, Marc and Bitsch, Friedemann}, publisher = {Springer Nature}, address = {Cham}, doi = {10.1007/978-3-031-14835-4_2}, pages = {17 -- 30}, abstract = {Development and verification of modern, dependable automotive systems require appropriate modelling approaches. Classic automotive safety is described by the normative regulations ISO 26262, its relative ISO/PAS 21448, and their respective methodologies. In recent publications, an emerging demand to combine environmental influences, machine learning, or reasoning under uncertainty with standard-compliant analysis techniques can be noticed. Therefore, adapting established methods like FTA and proper tool support is necessary. We argue that Bayesian Networks (BNs) can be used as a central component to address and merge these demands. In this paper, we present our Open-Source Python package BayesianSafety. First, we review how BNs relate to data-driven methods, model-to-model transformations, and causal reasoning. Together with FTA and ETA, these models form the core functionality of our software. After describing currently implemented features and possibilities of combining individual modelling approaches, we provide an informal view of the tool's architecture and of the resulting software ecosystem. By comparing selected publicly available safety and reliability analysis libraries, we outline that many relevant methodologies yield specialized implementations. Finally, we show that there is a demand for a flexible, unifying analysis tool that allows researching system safety by using multi-model and multi-domain approaches.}, language = {en} } @inproceedings{MaierGrabingerUrlhartetal., author = {Maier, Robert and Grabinger, Lisa and Urlhart, David and Mottok, J{\"u}rgen}, title = {Towards Causal Model-Based Engineering in Automotive System Safety}, series = {Model-Based Safety and Assessment, 8th International Symposium, IMBSA 2022: Munich, Germany, September 5-7, 2022, Proceedings}, booktitle = {Model-Based Safety and Assessment, 8th International Symposium, IMBSA 2022: Munich, Germany, September 5-7, 2022, Proceedings}, editor = {Seguin, Christel and Zeller, Marc and Prosvirnova, Tatiana}, publisher = {Springer Nature}, address = {Cham}, doi = {10.1007/978-3-031-15842-1_9}, pages = {116 -- 129}, abstract = {Engineering is based on the understanding of causes and effects. Thus, causality should also guide the safety assessment of complex systems such as autonomous driving cars. To ensure the safety of the intended functionality of these systems, normative regulations like ISO 21448 recommend scenario-based testing. An important task here is to identify critical scenarios, so-called edge and corner cases. Data-driven approaches to this task (e.g. based on machine learning) cannot adequately address a constantly changing operational design domain. Model-based approaches offer a remedy - they allow including different sources of knowledge (e.g. data, human experts) into safety considerations. With this paper, we outline a novel approach for ensuring automotive system safety. We propose to use structural causal models as a probabilistic modelling language to combine knowledge about an open-context environment from different sources. Based on these models, we investigate parameter configurations that are candidates for critical scenarios. In this paper, we first discuss some aspects of scenario-based testing. We then provide an informal introduction to causal models and relate their development lifecycle to the established V-model. Finally, we outline a generic workflow for using causal models to identify critical scenarios and highlight some challenges that arise in the process.}, language = {en} } @article{MaierGrabingerUrlhartetal., author = {Maier, Robert and Grabinger, Lisa and Urlhart, David and Mottok, J{\"u}rgen}, title = {Causal Models to Support Scenario-Based Testing of ADAS}, series = {IEEE Transactions on Intelligent Transportation Systems}, journal = {IEEE Transactions on Intelligent Transportation Systems}, publisher = {IEEE}, issn = {1524-9050}, doi = {10.1109/TITS.2023.3317475}, pages = {1 -- 17}, abstract = {In modern vehicles, system complexity and technical capabilities are constantly growing. As a result, manufacturers and regulators are both increasingly challenged to ensure the reliability, safety, and intended behavior of these systems. With current methodologies, it is difficult to address the various interactions between vehicle components and environmental factors. However, model-based engineering offers a solution by allowing to abstract reality and enhancing communication among engineers and stakeholders. Applying this method requires a model format that is machine-processable, human-understandable, and mathematically sound. In addition, the model format needs to support probabilistic reasoning to account for incomplete data and knowledge about a problem domain. We propose structural causal models as a suitable framework for addressing these demands. In this article, we show how to combine data from different sources into an inferable causal model for an advanced driver-assistance system. We then consider the developed causal model for scenario-based testing to illustrate how a model-based approach can improve industrial system development processes. We conclude this paper by discussing the ongoing challenges to our approach and provide pointers for future work.}, language = {en} } @inproceedings{MaierMottok, author = {Maier, Robert and Mottok, J{\"u}rgen}, title = {Causality and Functional Safety - How Causal Models Relate to the Automotive Standards ISO 26262, ISO/PAS 21448, and UL 4600}, series = {27th International Conference on Applied Electronics (AE): 06-07 September 2022, Pilsen, CZ}, booktitle = {27th International Conference on Applied Electronics (AE): 06-07 September 2022, Pilsen, CZ}, publisher = {IEEE}, doi = {10.1109/AE54730.2022.9920053}, pages = {6}, abstract = {With autonomous driving, the system complexity of vehicles will increase drastically. This requires new approaches to ensure system safety. Looking at standards like ISO 26262 or ISO/PAS 21448 and their suggested methodologies, an increasing trend in the recent literature can be noticed to incorporate uncertainty. Often this is done by using Bayesian Networks as a framework to enable probabilistic reasoning. These models can also be used to represent causal relationships. Many publications claim to model cause-effect relations, yet rarely give a formal introduction of the implications and resulting possibilities such an approach may have. This paper aims to link the domains of causal reasoning and automotive system safety by investigating relations between causal models and approaches like FMEA, FTA, or GSN. First, the famous "Ladder of Causation" and its implications on causality are reviewed. Next, we give an informal overview of common hazard and reliability analysis techniques and associate them with probabilistic models. Finally, we analyse a mixed-model methodology called Hybrid Causal Logic, extend its idea, and build the concept of a causal shell model of automotive system safety.}, language = {en} } @article{LohmeyerShamoninChamonineHertel, author = {Lohmeyer, Manfred and Shamonin (Chamonine), Mikhail and Hertel, Peter}, title = {Boundary conditions for the finite difference beam propagation method based on plane wave solutions of the Fresnel equation}, series = {IEEE Journal of Quantum Electronics}, volume = {33}, journal = {IEEE Journal of Quantum Electronics}, number = {2}, issn = {0018-9197}, doi = {10.1109/3.552269}, pages = {279 -- 286}, abstract = {Each particular implementation of the beam propagation method (BPM) requires a special procedure allowing for radiation to leave the computational window. We propose a new approach to constructing the finite difference schemes of the BPM at the boundary of the computational window. These schemes are independent of the computed fields and allow for a similar treatment of both interior and boundary points. The new approach can be further improved by correcting the field values at the boundary points according to Hadley's method. The algorithm is easy to implement for both two- and three-dimensional structures. The new method considerably reduces computation times because the propagation matrices remain constant in longitudinally invariant sections, thus avoiding repeated LU-decompositions. The basic idea-establishing the finite difference scheme such that locally exact, approximate, or plausible solutions are recovered-may be of interest for other efforts to solve partial differential equations by the finite difference method.}, language = {en} } @article{ShamoninChamonineLohmeyerHertel, author = {Shamonin (Chamonine), Mikhail and Lohmeyer, Manfred and Hertel, Peter}, title = {Analysis of power-dependent switching between radiatively coupled planar waveguides}, series = {Journal of Lightwave Technology}, volume = {15}, journal = {Journal of Lightwave Technology}, number = {6}, publisher = {IEEE}, address = {New York}, doi = {10.1109/50.588671}, pages = {983 -- 989}, abstract = {Effective coupling between two remote optical waveguides without branching sections can be achieved in a three-guide system with multimode central waveguide. We investigate the nonlinear power switching of c.w. laser radiation by such radiatively coupled waveguides. It is shown that effective all-optical switches with spatially well separated input/output channels can be realized although the influence of multimode interference on the switching characteristics becomes more pronounced for increasing thickness of the central guide. Different coupling regimes are specified, and the changes in switching characteristics during the transformation from one regime to another is studied. Numerical calculations for the critical power are compared with an approximate analytical expression. It is also shown that, at a moderate input power, a small number of modes determines the switching behavior.}, language = {en} } @article{LohmeyerShamoninChamonineBahlmannetal., author = {Lohmeyer, Manfred and Shamonin (Chamonine), Mikhail and Bahlmann, N. and Hertel, Peter and Dotsch, H.}, title = {Radiatively Coupled Waveguide Concept for an Integrated Magneto-Optic Circulator}, series = {MRS Online Proceedings Library}, journal = {MRS Online Proceedings Library}, number = {517}, issn = {1946-4274}, doi = {10.1557/PROC-517-519}, pages = {519 -- 524}, abstract = {Three-guide couplers with multimode central waveguides allow for remote coupling between optical channels. A simple three mode approximation turns out to be sufficient for the description of the main features of the power transfer behavior. The specific form of the relevant modes suggests the design of integrated optical isolators and circulators based on magnetic garnet materials. These novel devices are superior to conventional nonreciprocal couplers with respect to the total length and admissible fabrication tolerances. We characterize the isolation performance and the transmission loss for the proposed devices by propagating mode simulations and estimate the influence of geometry parameter deviations.}, language = {en} } @inproceedings{MonkmanDragoiEgersdoerferetal., author = {Monkman, Gareth J. and Dragoi, Daniel and Egersd{\"o}rfer, Stefan and F{\"u}chtmeier, Bernd and Nerlich, Michael}, title = {Der Roboter als Hilfsmittel in der Chirurgie // International Mechatronik Forum, Linz, October 2006}, series = {International Mechatronik Forum, Linz}, booktitle = {International Mechatronik Forum, Linz}, language = {de} } @inproceedings{KristenEnglMottok, author = {Kristen, Meret and Engl, Fabian and Mottok, J{\"u}rgen}, title = {Enhancing Phishing Detection: An Eye-Tracking Study on User Interaction and Oversights in Phishing Emails}, series = {SECURWARE 2024 : The Eighteenth International Conference on Emerging Security Information, Systems and Technologies, November 03-07, 2024, Nice, France}, booktitle = {SECURWARE 2024 : The Eighteenth International Conference on Emerging Security Information, Systems and Technologies, November 03-07, 2024, Nice, France}, publisher = {IARIA}, isbn = {978-1-68558-206-7}, pages = {71 -- 80}, abstract = {Phishing remains a significant threat to organizational security, necessitating effective countermeasures. This paper presents findings from an in-depth eye-tracking study with 103 participants, evaluating the effectiveness of phishing awareness tools and trainings. The study examines how a phishing awareness system influences user behavior, efficiency, and the ability to identify phishing attempts. By analyzing eye movements, the study reveals real-time interactions and oversights, providing insights into the decision-making process. Results indicate that while the system improves the efficiency of users already proficient in phishing detection, it does not universally enhance recognition rates. Notably, participants using the tool spent significantly less time looking at attachment-related phishing markers, indicating partial efficiency improvements. Since phishing attempts containing suspicious attachments were successful in 19\% of cases, as compared to an overall phishing success rate of 15\%, the phishing awareness tool is particularly useful here. A usability evaluation revealed that users reporting a higher perceived usability score profited more from the help of the tool. Additionally, no improvement in phishing detection rates was observed in users who had completed prior IT-security training, highlighting the necessity for a paradigm shift in phishing training to adequately prepare users for phishing attempts.}, language = {en} } @inproceedings{SetzpfandtSolntsevTitcheneretal., author = {Setzpfandt, Frank and Solntsev, Alexander S. and Titchener, James and Wu, Che Wen and Xiong, Chunle and Pertsch, Thomas and Schiek, Roland and Neshev, Dragomir N. and Sukhorukov, Andrey A.}, title = {Optically Tunable Entangled Photon State Generation in a Nonlinear Directional Coupler}, series = {Nonlinear Optics [Kauai, Hawaii 26-31 July 2015]}, booktitle = {Nonlinear Optics [Kauai, Hawaii 26-31 July 2015]}, number = {paper NW2A.4}, publisher = {OSA}, address = {Washington, D.C.}, isbn = {978-1-55752-001-2}, doi = {10.1364/nlo.2015.nw2a.4}, abstract = {We propose and experimentally demonstrate an all-optically tunable biphoton quantum light source using a nonlinear directional coupler. The source can generate high-fidelity N00N states, completely split states, and states with variable degrees of entanglement.}, language = {en} } @misc{FuechtmeierNerlichMonkmanetal., author = {F{\"u}chtmeier, Bernd and Nerlich, Michael and Monkman, Gareth J. and Egersd{\"o}rfer, Stefan and Raja, Kashif}, title = {Development of a Robotic Navigation and Fracture Fixation System - 7th Intl. Conf. Medical Aspects of Telemedicine, 23 September 2002}, series = {European Journal of Medical Research; Abstracts}, journal = {European Journal of Medical Research; Abstracts}, publisher = {Biomed Central}, address = {London}, issn = {2047-783X}, pages = {28 -- 29}, language = {en} } @misc{FuechtmeierEgersdoerferMonkmanetal., author = {F{\"u}chtmeier, Bernd and Egersd{\"o}rfer, Stefan and Monkman, Gareth J. and Nerlich, Michael}, title = {Entwicklung eines Systems zur navigierten und robotergest{\"u}tzten Frakturfixation}, series = {Zweite Jahrestagung der Deutschen Gesellschaft f{\"u}r Computer- und Roboterassistierte Chirurgie : 4.-7. November 2003, N{\"u}rnberg, Germany; CURAC 2003; Abstract CD-ROM}, journal = {Zweite Jahrestagung der Deutschen Gesellschaft f{\"u}r Computer- und Roboterassistierte Chirurgie : 4.-7. November 2003, N{\"u}rnberg, Germany; CURAC 2003; Abstract CD-ROM}, address = {Erlangen-N{\"u}rnberg}, language = {de} } @inproceedings{StauferHauserGrabingeretal., author = {Staufer, Susanne and Hauser, Florian and Grabinger, Lisa and Bittner, Dominik and Nadimpalli, Vamsi Krishna and Mottok, J{\"u}rgen}, title = {Learning elements in online learning management systems}, series = {Proceedings of the 16th annual International Conference of Education, Research and Innovation (ICERI 2023), Seville, Spain, 11/13/2023 - 11/14/2023}, booktitle = {Proceedings of the 16th annual International Conference of Education, Research and Innovation (ICERI 2023), Seville, Spain, 11/13/2023 - 11/14/2023}, editor = {G{\´o}mez Chova, Luis and Gonz{\´a}lez Mart{\´i}nez, Chelo and Lees, Joanna}, publisher = {IATED}, doi = {10.21125/iceri.2023.0815}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-67725}, pages = {3121 -- 3130}, language = {en} } @techreport{MartererKemeterLangetal., author = {Marterer, Verena and Kemeter, Dominik and Lang, Andreas and Dischner, Alexander and Huber, Stephanie and Obermeier, Maximilian and Langer, Tobias}, title = {FMS-Berichte Sommersemester 2021}, editor = {Meier, Hans and Niemetz, Michael and Reindl, Andrea}, address = {Regensburg}, doi = {10.35096/othr/pub-2104}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-21040}, pages = {VI, 37}, abstract = {Dieser Bericht entstand auf Initiative der Studierenden des 2020 neu gegr{\"u}ndeten Masterstudiengangs „Elektro- und Informationstechnik (MEI)", die an der Pflichtlehrveranstaltung „Forschungsmethoden und Seminar (FMS)" im Sommersemester 2021 teilnahmen. Diese Lehrveranstaltung hat das Ziel, systematisch an das wissenschaftliche Arbeiten, speziell die Wissenschaftskommunikation, heranzuf{\"u}hren. Daher war geeignete Literatur zu einem individuellen Thema zu recherchieren, Ver{\"o}ffentlichungen auf ihre Relevanz hin zu beurteilen und letztendlich eine eigene Ausarbeitung basierend auf der Literaturrecherche zu erarbeiten und diese in einem Vortrag zu pr{\"a}sentieren. Parallel dazu erfolgte im Theorieteil die entsprechende Hinf{\"u}hrung zu den verschiedenen Elementen der Wissenschaftskommunikation: • Bedeutung der Wissenschaftskommunikation f{\"u}r die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualit{\"a}t aufgefundener Fachliteratur, Auswahl geeigneter Materialien f{\"u}r die eigene Arbeit • Aufbereitung und Darstellung der recherchierten technischer Inhalte in Form einer seitenanzahlbegrenzten wissenschaftlichen Ausarbeitung • Einhalten formaler Randbedingungen bzgl. Strukturierung, einschl. Bildnachweise und Zitationsstile • Peer-review-Prozess bei wertsch{\"a}tzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschul{\"o}ffentlicher Pr{\"a}sentation der Ergebnisse • F{\"u}hren m{\"u}ndlicher wissenschaftlicher Diskurse Nachdem die Masterstudierenden in der Regel {\"u}ber noch keine eigene wissenschaftliche Forschungserfahrung bzw. -inhalte verf{\"u}gen, lag der w{\"a}hlbare Schwerpunkt der Literatursuche auf der Bearbeitung von vorgegeben aktuellen technischen oder gesellschaftspolitischen Forschungsthemen.}, subject = {Elektrotechnik}, language = {de} } @misc{Marterer, type = {Master Thesis}, author = {Marterer, Verena}, title = {A Characterisation of Motives and Barriers to Taking up Academic Study in the Field of Electrical Engineering}, address = {Regensburg}, doi = {10.35096/othr/pub-6255}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-62550}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {159}, abstract = {The problem description comes to the fore when the wide-ranging subject area of electrical engineering is combined and analyzed with different types of schools. It is becoming increasingly rare for elementary school children to come to grips with technology in the sense of recognizing functional interrelationships and understanding modes of action in the context of technical-practical confrontation. The picture at secondary schools is also rather sobering. Here, a strong focus on facts and knowledge and too little emphasis on modeling, application and problem solving lead to insufficient results in the cognitive area. In addition, a massive shortage of engineers and specialists with a technical and scientific orientation has been predicted for years and is being increasingly observed. The motivation of students in traditional lectures is decreasing and in general there is a decline of university students in technical subjects. These problems are not only known throughout Germany, but also internationally. Especially in developing countries, additional problems make technical education more difficult, regardless of the type of school. Therefore, this master thesis is evaluated in South Africa in order to consider as many influencing factors as possible. "Learning is experience. Everything else is simply information." - Methods and concepts developed in the thesis build upon this quote of Albert Einstein. Teaching methods are elaborated and applied for three different age groups and school types, depending on known influencing factors. The aim of this thesis is not to produce further findings in the sense of basic research, but to show ways in which the current situation can be steered in a different direction. It has been shown that technology lessons in elementary/secondary schools inspire interest in technical professions in the field of electrical engineering. Furthermore, the combination of frontal teaching, for a necessary theoretical background, together with student-active, action-oriented teaching shows advantages in terms of learning efficiency and an increase in performance levels for all three age groups. However, it could also be observed that factors such as social background, family influence and gender have partial effects on the promotion and education in the field of electrical engineering.}, language = {en} } @masterthesis{Marterer, type = {Bachelor Thesis}, author = {Marterer, Verena}, title = {Simulation der elektromagnetischen Eigenschaften von gestricktem Stoff}, address = {Regensburg}, doi = {10.35096/othr/pub-5760}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-57605}, school = {Ostbayerische Technische Hochschule Regensburg}, abstract = {Periodische Strukturen besitzen eine Reihe interessanter Eigenschaften, die sie unter anderem f{\"u}r den Einsatz im Bereich der Hochfrequenz- und Mikrowellentechnik attraktiv erscheinen lassen. In der vorliegenden Arbeit steht insbesondere deren Anwendung beim Entwurf gestrickter Stoffe, die auf metallischen F{\"a}den basieren, im Vordergrund. Es wird in diesem Zusammenhang zun{\"a}chst die vollst{\"a}ndige Modellierung der Struktur unter Verwendung von 3D-Elementen in repr{\"a}sentativen Elementarzellen durchgef{\"u}hrt. Innerhalb der Designumgebung von CST Studio Suite kann das analytische Elementarmodell von Leaf und Glaskin f{\"u}r die Einfaden-Maschenware implementiert werden. Abh{\"a}ngig von den variablen Faktoren beim Stricken bewegen sich die Kantenl{\"a}ngen der hier betrachteten Einheitszelle in der Gr{\"o}ßenordnung von 1 cm bis 2 cm. Bei der Analyse der elektromagnetischen Eigenschaften unter Verwendung eines Frequenzbereichsl{\"o}sers k{\"o}nnen somit die Streuparameter f{\"u}r Reflexion und Transmission in einem Frequenzbereich von 13 GHz bis 30 GHz ermittelt werden. Aus den 1D-Simulationsergebnissen werden Frequenzen sichtbar, bei denen Resonanzph{\"a}nomene auftreten. Die polarisationsabh{\"a}ngigen Strukturen weisen Abschirmwirkungen von 30 dB und mehr auf. Da das Resonanzverhalten mit den Oberfl{\"a}chenstr{\"o}men in Verbindung steht, wird die Oberfl{\"a}chenstromverteilung zeitgleich mit dem elektrischen Feld untersucht. Weiterhin wird den Wechselwirkungen zwischen den ver{\"a}nderlichen Strickparametern und den elektromagnetischen Spezifikationen wie Resonanzfrequenz, Bandbreite oder G{\"u}te Aufmerksamkeit geschenkt. Es wird deutlich, dass Optimierungsroutinen die M{\"o}glichkeit nahelegen, frequenzselektive gestrickte Strukturen f{\"u}r diverse Anwendungen maßzuschneidern.}, language = {de} } @article{ShamoninChamonineLohmeyerHertel, author = {Shamonin (Chamonine), Mikhail and Lohmeyer, Manfred and Hertel, Peter}, title = {Directional coupler based on radiatively coupled waveguides}, series = {Applied optics (Appl. Opt.)}, volume = {36}, journal = {Applied optics (Appl. Opt.)}, number = {3}, doi = {10.1364/ao.36.000635}, pages = {635 -- 641}, abstract = {We investigate a system of two waveguides with leaky modes sharing a common substrate (radiatively coupled waveguides). The main advantage of such a system is the possibility of remote coupling. A perturbation theory is developed for both TE and TM polarization. Numerical calculations of dispersion curves and of the coupling length allow us to determine the limitations of the perturbation theory. We study the influence of multimode interference on the process of beating by considering the propagation of a given initial field. Finally, we propose a new design for an effective, integrated optical TE-TM polarization splitter.}, language = {en} } @inproceedings{MayerMonkman, author = {Mayer, Matthias and Monkman, Gareth J.}, title = {Modern permanent magnetic materials: Advances and limits}, series = {Inductica - Berlin Messe, 22-24 May 2007}, booktitle = {Inductica - Berlin Messe, 22-24 May 2007}, language = {en} } @article{MartererRadouchovaSoukupetal., author = {Marterer, Verena and Radouchov{\´a}, Michaela and Soukup, Radek and Hipp, Susanne and Blecha, Tom{\´a}š}, title = {Wearable textile antennas: investigation on material variants, fabrication methods, design and application}, series = {Fashion and Textiles}, volume = {11}, journal = {Fashion and Textiles}, publisher = {Springer Open}, doi = {10.1186/s40691-023-00369-1}, abstract = {With the ongoing miniaturization of wireless devices, the importance of wearable textiles in the antenna segment has increased significantly in recent years. Due to the widespread utilization of wireless body sensor networks for healthcare and ubiquitous applications, the design of wearable antennas offers the possibility of comprehensive monitoring, communication, and energy harvesting and storage. This article reviews a number of properties and benefits to realize comprehensive background information and application ideas for the development of lightweight, compact and low-cost wearable patch antennas. Furthermore, problems and challenges that arise are addressed. Since both electromagnetic and mechanical specifications must be fulfilled, textile and flexible antennas require an appropriate trade-off between materials, antenna topologies, and fabrication methods—depending on the intended application and environmental factors. This overview covers each of the above issues, highlighting research to date while correlating antenna topology, feeding techniques, textile materials, and contacting options for the defined application of wearable planar patch antennas.}, language = {en} } @misc{Marterer, author = {Marterer, Verena}, title = {Simulation of the Electromagnetic Properties of Knitted Structures}, pages = {22}, abstract = {Designing textile Antennas is still challenging, as normal antenna design does not account for the textile nature of the materials: The e-Tex project investigates knitted and embroidered antennas to enhance the design process. The presentation shows first investigations in particular of knitted structures using measurement, simulation and theoretical models. In addition, plans to include measured models in simulation, in order to yield accurate results, will be presented.}, language = {en} } @misc{SorokinStepanovVasilievetal., author = {Sorokin, Vladislav V. and Stepanov, Gennady V. and Vasiliev, V. G. and Kramarenko, Elena Yu and Mayer, Matthias and Shamonin (Chamonine), Mikhail and Monkman, Gareth J.}, title = {Investigation of Dynamic Modulus and Normal Force of Magnetorheological Elastomers with Soft and Hard Magnetic Fillers}, series = {NANO 2014, July 13 - 18, 2014, Moscow ; Section 06 - Polymer, Organic and Other Soft Matter Materials}, journal = {NANO 2014, July 13 - 18, 2014, Moscow ; Section 06 - Polymer, Organic and Other Soft Matter Materials}, address = {Moscow}, language = {en} } @inproceedings{MartererMuhrSoukupetal., author = {Marterer, Verena and Muhr, Franz-Xaver and Soukup, Radek and Hipp, Susanne and Blecha, Tom{\´a}š}, title = {Material Characterization Using Waveguide Measurement Technique for the Development of Textile Antennas}, series = {2025 19th European Conference on Antennas and Propagation (EuCAP), Stockholm, Sweden, 3/30/2025 - 4/4/2025}, booktitle = {2025 19th European Conference on Antennas and Propagation (EuCAP), Stockholm, Sweden, 3/30/2025 - 4/4/2025}, publisher = {IEEE}, isbn = {978-88-31299-10-7}, doi = {10.23919/EuCAP63536.2025.10999278}, pages = {1 -- 5}, abstract = {Significant advances in using conductive textiles have been made over the past two decades, particularly in knitted fabrics. The aim is to deepen understanding of how knitted structures, especially those with hybrid yarns containing fine conductive elements (microwires), interact with electromagnetic fields. To establish simulation models that align with subsequent measurements, it is crucial to determine the dielectric properties, specifically relative permittivity and loss tangent/conductivity. This research investigates whether knitted structures with hybrid yarns exhibit anisotropic permittivity, meaning different dielectric properties along orthogonal axes within the fabric plane. These properties were measured using a waveguide technique' whereby the structures were rotated by 90° to observe changes. The results demonstrate that the knitted structure exhibits metallic-like reflective behavior in one direction, while rotation leads to dielectric material characteristics. This effect is influenced by the number of conductive microwires and the materials used for these wires, such as silver-plated copper or bronze.}, language = {en} } @techreport{BergmeierBockFischeretal., author = {Bergmeier, Sonja and Bock, Maximilian and Fischer, Lukas and Flassig, Nathanael and Hidv{\´e}gi, Barnab{\´a}s and B{\"a}cher, Tim and Hierl, Jonas and Kaltenbach, Dominik and Lackermeier, Florian and Laubmann, Julia and Liebl, Jonas and Pirthauer, Tobias and Reif, Robin and Roider, Stefan}, title = {FMS-Berichte Wintersemester 2024/25}, series = {FMS-Berichte Wintersemester 2024/25}, volume = {2024}, journal = {FMS-Berichte Wintersemester 2024/25}, number = {9}, editor = {Fuhrmann, Thomas and Hipp, Susanne and Niemetz, Michael and Sterz, Oliver}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg / Fakult{\"a}t Elektro- und Informationstechnik}, doi = {10.35096/othr/pub-8312}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-83121}, pages = {76}, abstract = {Dieser Bericht entstand urspr{\"u}nglich auf Initiative der Studierenden des damals neuen Masterstudiengangs „Elektro- und Informationstechnik (MEI)" an der OTH Regensburg, die an der Pflichtlehrveranstaltung „Forschungsmethoden und Seminar (FMS)" im Wintersemester 2020/21 teilnahmen. Diese Lehrveranstaltung hat das Ziel, systematisch an das wissenschaftliche Arbeiten, speziell die Wissenschaftskommunikation, heranzuf{\"u}hren. Daher ist im Laufe der Veranstaltung geeignete Literatur zu einem individuellen Thema zu recherchieren, sind Ver{\"o}ffentlichungen auf ihre Relevanz hin zu beurteilen und letztendlich gilt es eine eigene Ausarbeitung basierend auf der Literaturrecherche zu erstellen und diese in einem Vortrag zu pr{\"a}sentieren. Parallel dazu wird im Theorieteil die entsprechende Hinf{\"u}hrung zu den verschiedenen Elementen der Wissenschaftskommunikation vermittelt: • Bedeutung der Wissenschaftskommunikation f{\"u}r die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualit{\"a}t aufgefundener Fachliteratur, Auswahl geeigneter Materialien f{\"u}r die eigene Arbeit • Aufbereitung und Darstellung der recherchierten technischer Inhalte in Form einer seitenanzahlbegrenzten wissenschaftlichen Ausarbeitung • Einhalten formaler Randbedingungen bzgl. Strukturierung, einschl. Bildnachweise und Zitationsstile • Peer-review-Prozess bei wertsch{\"a}tzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschul{\"o}ffentlicher Pr{\"a}sentation der Ergebnisse • F{\"u}hren m{\"u}ndlicher wissenschaftlicher Diskurse Die pr{\"a}sentierten Themen beruhen nicht auf eigener Forschungst{\"a}tigkeit, sondern sind als einf{\"u}hrende Reviewartikel zum jeweiligen vorgegebenen technischen oder gesellschaftspolitischen Forschungsthema zu verstehen.}, subject = {Elektrotechnik}, language = {mul} } @inproceedings{SetzpfandtSolntsevTitcheneretal., author = {Setzpfandt, Frank and Solntsev, Alexander S. and Titchener, James and Wu, Che Wen and Xiong, Chunle and Pertsch, Thomas and Schiek, Roland and Neshev, Dragomir N. and Sukhorukov, Andrey A.}, title = {Optically tunable entangled photon state generation in a nonlinear directional coupler}, series = {CLEO: QELS_Fundamental Science 2015, San Jose, California, United States, 10-15 May 2015}, booktitle = {CLEO: QELS_Fundamental Science 2015, San Jose, California, United States, 10-15 May 2015}, publisher = {OSA}, address = {Washington, D.C.}, isbn = {978-1-55752-968-8}, doi = {10.1364/cleo_qels.2015.fth4d.3}, abstract = {We propose and experimentally demonstrate an all-optically tunable biphoton quantum light source using a nonlinear directional coupler. The source can generate high-fidelity N00N states, completely split states, and states with variable degrees of entanglement.}, language = {en} } @inproceedings{ForsterMayerRabindranathetal., author = {Forster, Eva and Mayer, Matthias and Rabindranath, Raman and Bentz, Alexander and B{\"o}se, Holger and Shamonin (Chamonine), Mikhail and Monkman, Gareth J.}, title = {Surface Control Magneto-Active Polymers (MAP)}, series = {EuroEAP 2011, First international conference on Electromechanically Active Polymer (EAP) transducers \& artificial muscles, Pisa, 8-9 June}, booktitle = {EuroEAP 2011, First international conference on Electromechanically Active Polymer (EAP) transducers \& artificial muscles, Pisa, 8-9 June}, abstract = {Smart materials change their properties with external energy supply. Besides the known ferro-fluids and Magneto Rheological Fluid (MRF) also the Electro Active Polymer (EAP) and Magneto Rheological Elastomer (MRE) belong to these intelligent materials. The latest generation of magnetic elastomers represents a new class of composite materials. This consists of small magnetized particles which are sized in the micron or even nanometer range that in turn is bounded in a highly elastic rubber matrix. These materials are very often called MRE. Only recently, it has managed to develop these materials even further, so that very soft composite materials with a young?s modulus up to 10 kPa are possible. These soft polymers could be named magneto-active polymers. The combination of polymers with magnetic materials show novel and often enhanced properties. A precisely controllable young?s modulus and hardness, giant and non-homogeneous deformation behavior and rapid response to the magnetic field opens up new possibilities for various applications. Since MAP represent a very new technology, the behavior of these materials as a function of their composition and external conditions so far are not yet sufficiently understood. Therefore, some fundamental studies are necessary. In this paper, the mechanical surface properties are studied using a micro hardness meter. This work shows the possibility to control mechanical properties at the surface of MAP with new developed magnetic systems.}, language = {en} } @article{RauchBrueckl, author = {Rauch, Johannes and Br{\"u}ckl, Oliver}, title = {Achieving Optimal Reactive Power Compensation in Distribution Grids by Using Industrial Compensation Systems}, series = {Electricity}, volume = {4}, journal = {Electricity}, number = {1}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/electricity4010006}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-59139}, pages = {78 -- 95}, abstract = {This paper presents a method for integrating industrial consumers owning compensation systems as alternative reactive power sources into grid operating processes. In remuneration, they receive a market-based provision of reactive power. The aim is to analyze the potential of reactive power compensation systems of industrial companies connected to medium-voltage (10 kV-30 kV) AC grids in order to increase the reactive power ability of distribution grids. Measurement methods and reactive power potential results of six industrial companies are presented to characterize the amount and temporal availability of their reactive power potential. The presented approach for using the decentralized reactive power potential is a centralized reactive power control method and is based on optimal power flow (OPF) calculations. An optimization algorithm based on linear programming is used to coordinate a reactive power retrieval tuned to the actual demand. The influencing quantities are the current grid status (voltage and load flow capacity reserves at grid nodes and power lines) and the current reactive power potential of the reactive power sources. The compensation impact of six measured industrial companies on an exemplary medium-voltage grid is shown by an application example.}, language = {en} } @inproceedings{SchweibererRauchBrueckl, author = {Schweiberer, Philipp and Rauch, Johannes and Br{\"u}ckl, Oliver}, title = {Control strategy for industrial reactive power sources depending on a specified reactive power setpoint value}, series = {ETG Kongress 2023: Die Energiewende beschleunigen, 25.-26. Mai 2023, Kassel, Germany}, booktitle = {ETG Kongress 2023: Die Energiewende beschleunigen, 25.-26. Mai 2023, Kassel, Germany}, publisher = {VDE VERLAG}, address = {Berlin}, organization = {Energietechnische Gesellschaft }, isbn = {978-3-8007-6108-1}, pages = {553 -- 558}, abstract = {Industrial plants can provide reactive power (Q) for system- and grid-serving behavior, for which a functioning reactive power management system is essential. To make reactive power retrieval as efficient and safe as possible, the selection of reactive power sources to meet the Q-demand must consider their sensitivities and the restrictions of the industrial grid, such as operating equipment utilization or voltage limits. On this basis, a concept for a sensitivity-based control strategy that manages the reactive power retrieval of multiple reactive power sources depending on a predefined reactive power demand value is proposed. Based on the simulation of an industrial plant in the medium-voltage grid, which can provide reactive power in the form of industrial compensation systems (ICS) and generators, the operation of the algorithm is shown.}, language = {en} } @article{EgersdoerferDragoiMonkmanetal., author = {Egersdoerfer, Stefan and Dragoi, Daniel and Monkman, Gareth J. and F{\"u}chtmeier, Bernd and Nerlich, Michael}, title = {Heavy duty robotic precision fracture repositioning}, series = {Industrial Robot}, volume = {31}, journal = {Industrial Robot}, number = {6}, publisher = {Emerald}, issn = {0143-991X}, doi = {10.1108/01439910410566344}, pages = {488 -- 492}, abstract = {The application of robotics in manufacturing industry is increasingly spreading to other fields such as service, security and medical, and more recently into orthopedic surgery. Most research projects to date have concentrated on the lighter side of non-invasive surgery, camera, laser guidance, light cutting and milling through bone. Just as in industrial production and processing applications, the choice of robot and its accompanying control and programming system is absolutely paramount. This simple fact has been justified in recent research dealing with the heavier forms of fracture repositioning robotics in accident surgery. This paper discusses the development of the complete system including robot, end-effector and sensors.}, language = {en} } @inproceedings{StauferNadimpalliHauseretal., author = {Staufer, Susanne and Nadimpalli, Vamsi Krishna and Hauser, Florian and Bittner, Dominik and Grabinger, Lisa and Bugert, Flemming and Ezer, Timur and R{\"o}hrl, Simon and Mottok, J{\"u}rgen}, title = {Persistence of Questionnaire Data on Learning Styles, Learning Strategies AND Personality Traits}, series = {ICERI2024 Proceedings: 17th Annual International Conference of Education, Research and Innovation, 11th-13th November 2024, Seville, Spain}, booktitle = {ICERI2024 Proceedings: 17th Annual International Conference of Education, Research and Innovation, 11th-13th November 2024, Seville, Spain}, publisher = {IATED}, isbn = {978-84-09-63010-3}, issn = {2340-1095}, doi = {10.21125/iceri.2024.1524}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-78246}, pages = {6310 -- 6319}, abstract = {In the context of learning, questionnaires are carried out to gain information about learners. This learner profile has various benefits, like adapting the learning content, promoting of self-reflection, or increasing motivation in learning and therefore better learning results. Some researchers take the results of such questionnaires as ground truth or trust them blindly. Examining how persistent questionnaires are, asking the same questions twice, and comparing the results is a way to prove or falsify this statement. Our research procedure compares the results of three different questionnaires. The first questionnaire is the ILS (index of learning styles) according to the Felder-Silverman Learning Style Model (FSLSM) with about 44 questions. Learning strategies are examined with the LIST-K questionnaire consisting of 39 questions after Klingsieck. The third and last questionnaire is about personality traits. With only ten questions, Rammstedt et al. describe the BFI-10 questionnaire for personality traits. To compare results, the same study with the three named questionnaires is carried out twice with three to four months in between. The sample includes 35 students in their bachelor studies taking the course Software Engineering in a blended learning format. After collecting the questionnaire data from the students, a comparison is made in two different ways. First, we compare the data points based on the given answers. Second, a comparison is made based on the calculated questionnaire results because each of the three questionnaires has its own analysis method. For example, the analysis method of the ILS delivers as a result four integers representing the four characteristics of a learning style, while LIST-K makes a factor analysis. The results of the paper show that both the given answers and the calculated questionnaire results differ. Not one student has given the same answer inside each questionnaire with causes, like a change of learning style, learning strategy, and personality traits, or not filling in conscientiously.}, language = {en} } @article{RoehrlStauferBugertetal., author = {R{\"o}hrl, Simon and Staufer, Susanne and Bugert, Flemming and Nadimpalli, Vamsi Krishna and Hauser, Florian and Grabinger, Lisa and Bittner, Dominik and Ezer, Timur and Altweck, Ricardo and Graf, Sabine and Kriza, Thomas and Mottok, J{\"u}rgen}, title = {Ethical Considerations of AI in Education: A Case Study based on Pythia Learning Enhancement System}, series = {IEEE Access}, volume = {11}, journal = {IEEE Access}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, issn = {2169-3536}, doi = {10.1109/ACCESS.2025.3583975}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-83403}, pages = {1 -- 25}, abstract = {As the use of AI in education increases, addressing ethical concerns is essential for its responsible use and implementation. This study explores the ethical considerations of AI in education by analyzing a concrete application, the Pythia Learning Enhancement System, which enables personalized and adaptive educational experiences. In this case study, the concrete implementation of Pythia, contrary to high-level abstract analyses, provides practical insights into these ethical issues. To achieve this goal, we first define Pythia and outline its implementation. Using the various topics covered by Pythia, the ethical issues associated with each of these topics are outlined, resulting in a list of ten distinct ethical issues. Because there is overlap in issues covered by similar applications, they can benefit from this identification. An ethical (human rights) and didactic (constructivism) theoretical background is then provided as a basis for further discussion. This is used to build the arguments used in the main study. This consists of analyzing each of the issues and providing recommendations to mitigate potential harm arising from these issues. This helps to provide guidelines for future applications. In the analysis, the ethical discussion is mainly based on the human rights of the stakeholders involved, emphasizing human dignity. After the analysis, each of the issues is contextualized with the recent AI Act of the European Union, providing a novel mapping of the issues of AI in education to the AI Act. Finally, the limitations of the study are stated and a plan for future research is presented.}, language = {en} } @article{MetschSchmidtSindersbergeretal., author = {Metsch, P. and Schmidt, Henrik and Sindersberger, Dirk and Kalina, K. A. and Brummund, J. and Auernhammer, G{\"u}nter and Monkman, Gareth J. and K{\"a}stner, Markus}, title = {Field-Induced Interactions in Magneto-Active Elastomers}, series = {Smart Materials and Structures}, volume = {29}, journal = {Smart Materials and Structures}, number = {8}, publisher = {IOPscience}, doi = {10.1088/1361-665X/ab92dc}, pages = {1 -- 10}, abstract = {In this contribution, field-induced interactions of magnetizable particles embedded into a soft elastomer matrix are analyzed with regard to the resulting mechanical deformations. By comparing experiments for two-, three- and four-particle systems with the results of finite element simulations, a fully coupled continuum model for magneto-active elastomers is validated with the help of real data for the first time. The model under consideration permits the investigation of magneto-active elastomers with arbitrary particle distances, shapes and volume fractions as well as magnetic and mechanical properties of the individual constituents. It thus represents a basis for future studies on more complex, realistic systems. Our results show a very good agreement between experiments and numerical simulations—the deformation behavior of all systems is captured by the model qualitatively as well as quantitatively. Within a sensitivity analysis, the influence of the initial particle positions on the systems' response is examined. Furthermore, a comparison of the full three-dimensional model with the often used, simplified two-dimensional approach shows the typical overestimation of resulting interactions in magneto-active elastomers.}, language = {en} } @inproceedings{YoshiokaSehrDelcroixetal., author = {Yoshioka, Takuya and Sehr, Armin and Delcroix, Marc and Kinoshita, Keisuke and Maas, Roland and Nakatani, Tomohiro and Kellermann, Walter}, title = {Survey on approaches to speech recognition in reverberant environments}, series = {Asia-Pacific Signal \& Information Processing Association annual summit and conference (APSIPA ASC), 2012 : Hollywood, California, USA, 3 - 6 Dec. 2012}, booktitle = {Asia-Pacific Signal \& Information Processing Association annual summit and conference (APSIPA ASC), 2012 : Hollywood, California, USA, 3 - 6 Dec. 2012}, publisher = {IEEE}, isbn = {978-0-6157-0050-2}, abstract = {This paper overviews the state of the art in reverberant speech processing from the speech recognition viewpoint. First, it points out that the key to successful reverberant speech recognition is to account for long-term dependencies between reverberant observations obtained from consecutive time frames. Then, a diversity of approaches that exploit the long-term dependencies in various ways is described, ranging from signal and feature dereverberation to acoustic model compensation tailored to reverberation. A framework for classifying those approaches is presented to highlight similarities and differences between them.}, language = {en} }