TY - CHAP A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Konzeptionierung netzplanerischer Prozessansätze zur Ermittlung von Blindleistungskapazitäten zum Ausgleich des Blindleistungsbedarfs in einer Netzregion T2 - Tagungsband Tagung Zukünftige Stromnetze 26./27. Januar 2022 (online) N2 - Um einen sicheren und zuverlässigen Stromnetzbetrieb zu gewährleisten, muss die Spannung im Grundfall als auch bei ungeplanten Ausfällen in definierten Bereichen gehalten werden. Im Übertragungsnetz wird hierfür bisher Blindleistung hauptsächlich aus Blindleistungskompensationsanlagen und konventionellen Großkraftwerken eingesetzt. Zukünftig wird nach §12h EnWG eine marktgestützte Beschaffung dieser Dienstleistung zur Spannungsregelung vorgeschrieben. Zugleich verändert sich der Blindleistungsbedarf der Netzbetriebsmittel durch die Integration erneuerbarer Energieanlagen und der Elektromobilität sowie durch den Netzausbau bei Übertragungs- und Verteilungsnetzbetreibern. Es bedarf somit angepasster Netzbetriebs- und Netzplanungskonzepte für ein technisch effizientes und wirtschaftlich günstiges Blindleistungsmanagement. Dieser Beitrag beschäftigt sich damit, Prozessansätze und Methodiken für ebendieses in der Netzplanung aufzuzeigen, um erforderliche Blindleistungskapazitäten unter minimalen Gesamtkostenaufwand und unter Berücksichtigung einer effizienten Blindleistungsbedarfsdeckung zu bestimmen. Dabei liegt der Fokus verstärkt in der Bedarfsanalyse. KW - Blindleistung KW - Blindleistungsmanagement KW - Netzplanungsprozesse KW - Spannungshaltung KW - Optimierungsverfahren Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-58665 SN - 978-3-948176-16-7 SP - 117 EP - 126 PB - Conexio-PSE GmbH CY - Pforzheim ER - TY - CHAP A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Analysis of the correlation behavior between local available information to the overall reactive power of a medium-voltage grid group T2 - Applied Research Conference - ARC 2017, 7 July 2017 München N2 - The initiated energy transition leads to extensive changes in the supply of energy. The increasing use of renewable energy causes a shift of the produced power from centralized conventional power plants to decentralized energy plants. Because of this redistribution and the related change of load-flows, new challenges and problems for distribution system operators appear. This includes the integration of new loads and plants into the existing power grid and the guarantee of a high supply security and quality. It also includes strengthened requirements for the use and provision of reactive power. The project “SyNErgie” (“Systemoptimierendes Netz- und Energiemanagement für Verteilungsnetze der Zukunft“) deals with the development of a new reactive power management, which gets embedded in grid planning and controlling processes. One focus of the project is on the integration of decentralized energy plants (DEPs) to the reactive power management. The aim is to develop a decentralized and self-sufficient reactive power control system, which only works with local available information (measures). Therefore is no necessity of a complex communication system to the grid control center. Self-controlled Q-controller in the DEPs get characteristic curves and control the reactive power sources with local measurements (e.g. current, voltage, effective power). This new reactive power control management aims for the reactive power compensation in order to increase the integration capacity of loads and plants in a grid [2]. In order to generate characteristic curves for DEPs, it is necessary to analyze the correlation behavior between the local available measurements at the DEPs and the overall-Q-behavior of the grid group at the transformer. In that regard, influencing quantities should be considered. The aim is to involve und evaluate all relevant influencing quantities in order to determine energy plants and certain operating points, in which the correlation behavior and the prediction for the overall-Q-behavior are sufficient. The next step is to develop a model that fits these correlation behaviors and generate characteristic curves. One method to generate characteristic curves for the Q-controllers is regression analysis. The developed Q-control-system with the characteristic curves will be tested, evaluated and optimized in a following field test in cooperation with distribution system operators. KW - Mittelspannungsnetz KW - Blindleistungsmanagement KW - Blindleistung KW - Integration Erneuerbare Energien KW - Potentialerschließung Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-58712 SP - 224 EP - 230 CY - München ER - TY - CHAP A1 - Schweiberer, Philipp A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Entwicklung eines Regelkonzeptes für einen optimierten Blindleistungsabruf auf Basis von Blindleistungspotentialanalysen bei Industriebetrieben im Mittelspannungsnetz T2 - Tagungsband Tagung Zukünftige Stromnetze 26./27. Januar 2022 (online) N2 - Im Zuge der Energiewende ergibt sich ein Wandel in der Struktur des Elektrizitätsversorgungsnetzes. Die Verschiebung der Erzeugungsleistung von konventionellen Großkraftwerken in höheren Netzebenen hin zu dezentralen erneuerbaren Energieanlagen in niedrigeren Netzebenen resultiert sowohl in bidirektionalen Lastflüssen als auch in schwankenden Einspeisecharakteristiken. Des Weiteren folgen durch den Wegfall von Großkraftwerken als Blindleistungsquellen Leistungsdefizite in der Übertragungsnetzebene, die kompensiert werden müssen. Daraus resultieren Herausforderungen an einen sicheren und zuverlässigen Betrieb der Verteil- und Übertragungsnetze. Neue Konzepte müssen für die Erbringung von Blindleistung entwickelt werden, es soll mehr Blindleistung aus dem Verteilungsnetz zur Verfügung gestellt werden, um die Systemstabilität zu wahren. Im Rahmen des Projektes Q-Integral wird das Thema „Blindleistung“ (Q) ganzheitlich untersucht. Es werden dazu verschiedene Erbringungsoptionen für Blindleistung hinsichtlich technischer und wirtschaftlicher Potentiale untersucht, die in ein funktionales und effizientes Blindleistungsmanagement eingebracht werden. Die Untersuchungsansätze dafür sind sowohl spannungsebenen-übergreifend als auch netzbetreiber-übergreifend. Ein Ansatzpunkt des Projektes ist die Betrachtung der Blindleistungsbereitstellung von Industriebetrieben. Dazu wird das Potential von Betrieben, die an das Verteilnetz angeschlossen sind und Blindleistung durch Kompensations- oder Erzeugungsanlagen bereitstellen können, untersucht. Ziel ist es, das gesicherte und maximale induktive sowie kapazitive Potential zu bestimmen. Das gesicherte kapazitive Potential kann genutzt werden, um Aussagen darüber zu treffen, wie stark dem Spannungsfall im vorgelagerten Netz zu Starklastzeiten entgegengewirkt werden kann. Anhand des gesicherten induktiven Potentials kann ein Spannungsanstieg während Schwachlastzeiten ausgeglichen werden kann. In diesem Beitrag werden Ergebnisse aus dem Projekt Q-Integral vorgestellt. Dazu werden zuerst die Berechnungsgrundlagen der induktiven und kapazitiven Blindleistungspotentiale aufgezeigt und die Ergebnisse der Berechnungen vorgestellt. Die gewonnen Ergebnisse entstammen aus Messungen an einem Industriebetrieb mit Blindleistungskompensationsanlagen (BKA), den entsprechenden Reglern der Anlagen und einer installierten Kompensationsleistung von 1600 kvar. Sowohl die Lastgänge als auch das Schaltverhalten der einzelnen Kompensationsanlagen liegen den Berechnungen zugrunde. Um den Austausch der Blindleistung an der Übergabestelle des Betriebs zum Mittelspannungsnetz netzdienlich einzustellen, bedarf es eines geeigneten Regelkonzepts, das neben den BKAs auch weitere Q-Quellen berücksichtigt. Deshalb wird abschließend ein Regelkonzept vorgestellt, das den technisch-optimierten Blindleistungsabruf unter Berücksichtigung mehrerer Blindleistungsquellen behandelt. KW - Blindleistung KW - Blindleistungsmanagement KW - Blindleistungsquellen KW - Blindleistungspotentiale KW - Industriebetriebe Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-58704 SN - 978-3-948176-16-7 SP - 224 EP - 233 PB - Conexio-PSE GmbH CY - Pforzheim ER - TY - CHAP A1 - Rauch, Johannes A1 - Brückl, Oliver A1 - Engel, Bernd ED - Schulz, Detlef T1 - Analysis and optimization of the steady state voltage deviation demand for reactive power planning using installed reactive power sources T2 - NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg N2 - The provision of reactive power is one option for maintaining the grid voltage, that is defined as an ancillary service in Germany. This paper presents an approach for determining deficient voltage deviation demands within an electrical grid for long term reactive power planning investigations. In contrast to previous approaches, which evaluate the Q-behavior of extended ward elements or grid assets, voltage deviations are analyzed bus-specifically. So further reactive power planning investigations are able to scale and optimize additional reactive power sources directly on planning voltage limits using load flow sensitivity techniques. The focus lies on the analysis of the steady state demand at base case conditions. Therefore, a grid planning process is conceptualized. An optimal power flow algorithm based on Differential Evolution is used for an optimal reactive power dispatch of installed reactive power sources, e. g. reactive power compensation systems or (renewable) energy sources to minimize the total voltage deviation according to voltage limits of Transmission System Operators planning principles. Methodological and processuals specifications as well as an application use case with an exemplary transmission system are presented in this paper. KW - Reactive Power KW - Reactiver Power Planning KW - Voltage Control KW - Optimal Power Flow KW - Differential Evolution Y1 - 2022 UR - https://ieeexplore.ieee.org/document/10048083 SN - 978-3-8007-5983-5 SN - 2510-6902 SP - 175 EP - 182 PB - VDE-Verlag CY - Berlin ER - TY - CHAP A1 - Schweiberer, Philipp A1 - Rauch, Johannes A1 - Brückl, Oliver ED - Schulz, Detlef T1 - Long-term analysis of industrial reactive power potentials with consideration of plant-internal grid restrictions using the example of an industrial plant in a distribution grid T2 - NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg N2 - Since conventional generation plants provide a considerable share of reactive power but are gradually being shut down due to energy transition, leading to power deficits at the transmission grid level, new concepts for the supply of reactive power must be developed. As one possibility for the latter, industrial plants in the distribution grid are considered suitable, as their reactive power potentials can contribute to voltage maintenance and thus to a grid- or system-serving behavior. In this paper, the determination of reactive power potentials provided by industrial compensation systems (ICS) is presented. An industrial plant in the medium voltage grid, with three installed ICSs, is investigated. The potentials are determined and described based on their time characteristics, which provide information about the occurrence and distribution of inductive and capacitive potentials. A grid simulation of the investigated industrial grid is used to analyze the effects of retrieving the reactive power potentials regarding equipment utilizations and voltage limits. KW - Reactive Power KW - Reactive Power Potentials KW - Industrial plant KW - Voltage Stability KW - Long term analysis Y1 - 2022 UR - https://ieeexplore.ieee.org/document/10048065 SN - 978-3-8007-5983-5 SN - 2510-6902 SP - 51 EP - 56 PB - VDE-Verlag CY - Berlin ER - TY - RPRT A1 - Brixner, Luis A1 - Gnerlich, Patrick A1 - Jakob, Jonas A1 - Kiener, Johannes A1 - Oberländer, Jonas A1 - Plößl, Moritz A1 - Schächinger, Stefan A1 - Stelz, Raphael A1 - Wartner, Felix ED - Fuhrmann, Thomas ED - Niemetz, Michael ED - Reindl, Andrea T1 - FMS-Berichte Wintersemester 2023/24 BT - Seminar zu aktuellen Themen der Elektro- und Informationstechnik N2 - Dieser Bericht entstand ursprünglich 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, heranzuführen. Daher ist im Laufe der Veranstaltung geeignete Literatur zu einem individuellen Thema zu recherchieren, sind Veröffentlichungen 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 präsentieren. Parallel dazu wird im Theorieteil die entsprechende Hinführung zu den verschiedenen Elementen der Wissenschaftskommunikation vermittelt: • Bedeutung der Wissenschaftskommunikation für die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualität aufgefundener Fachliteratur, Auswahl geeigneter Materialien für 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 wertschätzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschulöffentlicher Präsentation der Ergebnisse • Führen mündlicher wissenschaftlicher Diskurse Die präsentierten Themen beruhen nicht auf eigener Forschungstätigkeit, sondern sind als einführende Reviewartikel zum jeweiligen vorgegebenen technischen oder gesellschaftspolitischen Forschungsthema zu verstehen. T3 - Forschungsmethoden-Seminar - 7 KW - Elektrotechnik KW - Informationstechnik KW - Energietechnik KW - Literaturrecherche Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77796 IS - 1 CY - Regensburg ER - TY - RPRT A1 - Blößer, Julia A1 - Branilovic, Fabio A1 - Michael, Bretz A1 - Ebner, Andreas A1 - Gleich, Ralf A1 - Inderst, Christian A1 - Kopp, Lorenz A1 - Müller, Markus A1 - Schächiner, Michael A1 - von Beerfelde, Rebekka ED - Fuhrmann, Thomas ED - Niemetz, Michael ED - Reindl, Andrea T1 - FMS-Berichte Sommersemester 2024 BT - Seminar zu aktuellen Themen der Elektro- und Informationstechnik T2 - FMS-Berichte Sommersemester 2024 N2 - Dieser Bericht entstand ursprünglich 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, heranzuführen. Daher ist im Laufe der Veranstaltung geeignete Literatur zu einem individuellen Thema zu recherchieren, sind Veröffentlichungen 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 präsentieren. Parallel dazu wird im Theorieteil die entsprechende Hinführung zu den verschiedenen Elementen der Wissenschaftskommunikation vermittelt: • Bedeutung der Wissenschaftskommunikation für die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualität aufgefundener Fachliteratur, Auswahl geeigneter Materialien für 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 wertschätzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschulöffentlicher Präsentation der Ergebnisse • Führen mündlicher wissenschaftlicher Diskurse Die präsentierten Themen beruhen nicht auf eigener Forschungstätigkeit, sondern sind als einführende Reviewartikel zum jeweiligen vorgegebenen technischen oder gesellschaftspolitischen Forschungsthema zu verstehen. T3 - Forschungsmethoden-Seminar - 8 KW - Elektrotechnik KW - Informationstechnik KW - Energietechnik KW - Literaturrecherche Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77801 IS - 1 CY - Regensburg ER - TY - JOUR A1 - Radkovskaya, Anna A. A1 - Sydoruk, O. A1 - Shamonin (Chamonine), Mikhail A1 - Shamonina, Ekaterina A1 - Stevens, C. J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Solymar, L. T1 - Experimental study of a bi-periodic magnetoinductive waveguide: comparison with theory JF - IET Microwaves, Antennas & Propagation N2 - Magnetoinductive waves propagating along a line consisting of two kinds of metamaterial elements are studied. Both elements are made up by the same metallic loop but are loaded by different capacitors resulting in different resonant frequencies. The dispersion characteristics are derived from phase and amplitude measurements for the cases when the line consists of (i) identical elements and (ii) of alternating elements. Both planar (elements in the same plane as the axis of the line) and axial (elements perpendicular to the axis of the line) configurations are investigated. It is shown that in the bi-periodic arrangement of the elements, the dispersion curves have a forward wave in the lower frequency branch and a backward wave in the upper frequency branch independent of the configuration whether it is planar or axial. Comparisons between theoretical and experimental results show good agreement. KW - magnetic materials KW - metamaterials KW - wave propagation KW - dispersion (wave) KW - waveguides Y1 - 2007 U6 - https://doi.org/10.1049/iet-map:20050289 SN - 1751-8733 VL - 1 IS - 1 SP - 80 EP - 83 PB - IET ER - TY - GEN A1 - Hirmer, Marion A1 - Danilov, Sergey N. A1 - Giglberger, Stephan A1 - Putzger, Jürgen A1 - Niklas, Andreas A1 - Jäger, Andreas A1 - Hiller, Karl-Anton A1 - Schmalz, Gottfried A1 - Redlich, Britta A1 - Monkman, Gareth J. A1 - Ganichev, Sergey D. T1 - Spectroscopic Study of Human Teeth and Blood from Visible to Terahertz Frequencies for Clinical Diagnosis of Dental Pulp Vitality T2 - PACS, November 11, 2011 N2 - Transmission spectra of wet human teeth and dentin slices, together with blood of different flow rates were investigated. The measurements carried out over a wide spectral range, from visible light down to terahertz radiation. The results make it possible to find the optimum light frequency for an all-optical determination of pulpal blood flow and, consequently, for clinically diagnosis of tooth vitality. Y1 - 2011 ER - TY - CHAP A1 - Mayer, Matthias A1 - Forster, Eva A1 - Rabindranath, Raman A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Highly compliant Magneto-Active Polymers (MAPs) T2 - Actuator'11, Bremen, May 2011 Y1 - 2011 ER - TY - CHAP A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Ezer, Timur A1 - Mottok, Jürgen A1 - Gruber, Hans ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - Integrating deliberate practice in software engineering education T2 - ICERI 2024 Proceedings, 17th annual International Conference of Education, Research and Innovation,11-13 November, 2024, Seville, Spain Y1 - 2024 U6 - https://doi.org/10.21125/iceri.2024.1331 SP - 5457 EP - 5466 PB - IATED ER - TY - RPRT A1 - Rank, Daniel A1 - Heberl, Michael A1 - Sterner, Michael T1 - Die CO2-Bilanz der OTH [Ostbayerischen Technische Hochschule Regenburg] BT - Tool für Hochschulen und Firmen Y1 - 2020 UR - https://sae58cb7e2208a3d2.jimcontent.com/download/version/1613400473/module/9240277976/name/1. Sitzung AG_Präsentation Prof. Sterner-1.pdf ER - TY - CHAP A1 - Schrimer, M A1 - Putz, Christoph A1 - Monkman, Gareth J. ED - McConnell, Lynn T1 - Boron-Silicone-Oxide Polymers T2 - Boron: advances in research and applications Y1 - 2021 SN - 9781685072315 SN - 1685072313 U6 - https://doi.org/10.52305/AFKU5564 SP - 117 EP - 179 PB - Nova Science Publishers CY - New York, NY ER - TY - JOUR A1 - Unterreitmeier, M. A1 - Nagler, Oliver A1 - Pfitzner, L. A1 - Weigel, R. A1 - Holmer, Rainer T1 - An acoustic emission sensor system for thin layer crack detection JF - Microelectronics Reliability N2 - We present a new method for semiconductor layer characterization enabling simultaneous crack generation and detection based on the established acoustic emission testing. In this paper, we explain the test concept and failure mechanism of diamond tip indentation with acoustic wave measurement on oxide layers by analytical modeling and computer-aided simulations. For this purpose, an innovative design of a sensor-indenter system was developed and experimentally verified. In further tests, the new acoustic crack detection method is correlated with proven optical inspection methods and the good reproducibility of the measurement is demonstrated. The high sensitivity and resolution of this method offer new opportunities for thin layer characterization at lower time and cost. The new high-efficient method can be used especially for process qualification for semiconductor wafer test, where oxide cracks can be induced by sharp probes causing electrical failure of the chip. KW - FLAT KW - INDENTATION Y1 - 2018 U6 - https://doi.org/10.1016/j.microrel.2018.07.015 VL - 88-90 IS - September SP - 16 EP - 21 PB - Pergamon-Elsevier ER - TY - CHAP A1 - Schiek, Roland A1 - Setzpfandt, Frank A1 - Pertsch, Thomas A1 - Baronio, Fabio A1 - de Angelis, Costantino T1 - Spatial Rogue Waves in Quadratic Optical Slab Waveguides T2 - Advanced Photonics 2018 (BGPP, IPR, NP, NOMA, Sensors, Networks, SPPCom, SOF), OSA Techncail Digest (online) (Optica Publishing Group, 2018), paper NpTh1H.7 N2 - Spatial optical breather solutions of the Nonlinear Schrödinger Equation have been observed for the first time. The experiment was performed in an optical slab waveguide with the cascaded quadratic nonlinearity in second-harmonic generation. Y1 - 2018 SN - 978-1-943580-43-9 U6 - https://doi.org/10.1364/np.2018.npth1h.7 PB - OSA CY - Washington D.C. ER - TY - JOUR A1 - Zimmermann, Klaus A1 - Chavez Vega, Jhohan Harvey A1 - Becker, Tatiana I. A1 - Witte, Hartmut A1 - Schilling, Cornelius A1 - Köhring, Sebastian A1 - Böhm, Valter A1 - Monkman, Gareth J. A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Lutz, I. I. A1 - Merker, Lukas T1 - An approach to a form-adaptive compliant gripper element based on magneto-sensitive elastomers with a bioinspired sensorized surface JF - Problems of Mechanics Y1 - 2019 SN - 1512-0740 VL - 75 IS - 2 SP - 23 EP - 38 PB - Georgian Technical University CY - Tbilisi ER - TY - GEN A1 - Stark, T. A1 - Schreistetter, Stefan A1 - Reuter, Rebecca A1 - Hauser, Florian A1 - Holmqvist, Kenneth A1 - Mottok, Jürgen A1 - Gruber, Hans T1 - Learning from Gaze: Eye Movement Modeling Examples in Software Engineering Education T2 - Earli Book of Abstracts Y1 - 2021 UR - https://earli.org/assets/files/BOA-2021.pdf SP - 291 PB - Earli ER - TY - CHAP A1 - Setzpfandt, Frank A1 - Schiek, Roland A1 - Sohler, Wolfgang A1 - Pertsch, Thomas T1 - Nonlinear Nearest-Neighbor Coupling in Quadratic Waveguide Arrays T2 - Nonlinear Optics : Proceedings Nonlinear Optics 26-31 July 2015, Kauai, Hawaii, United States N2 - We investigate nonlinear coupling between neighboring waveguides in waveguide arrays with second-order nonlinearity. Using mode symmetries to suppress local nonlinearities, we experimentally show the profound effect of such nonlinear nearest-neighbor interactions on second-harmonic generation. Y1 - 2015 SN - 978-1-55752-001-2 U6 - https://doi.org/10.1364/nlo.2015.nm3b.6 PB - OSA CY - Washington, D.C. ER - TY - CHAP A1 - Al-Falouji, Ghassan A1 - Prestel, Dietmar A1 - Scharfenberg, Georg A1 - Mandl, Roland A1 - Deinzer, Arnulf A1 - Halang, W. A1 - Margraf-Stiksrud, Jutta A1 - Sick, B. A1 - Deinzer, Renate T1 - SMART-iBrush - Individuelle Unterstützung der Zahnreinigung durch Messung von Bewegung und Druck mit einer intelligenten Zahnbürsten T1 - SMART-iBrush - Individuelle Unterstützung der Zahnreinigung durch Messung von Bewegung und Druck mit einer intelligenten Zahnbürste T2 - Transdisziplinäre Konferenz Technische Unterstützungssysteme, die die Menschen wirklich wollen, 1, 2014, Gießen N2 - Der Forschungsansatz der intelligenten Zahnbürste (SMART-iBrush) verfolgt das Ziel, dass Menschen die für sie effektivste Zahnputzmethode unter individueller Anleitung der Zahnbürste interaktiv trainieren können. Hierzu wurde eine Zahnbürste entwickelt, die Bewegung und Druckverlauf erfasst. Daten werden an ein Smart Device übertragen und können dort in Echtzeit visualisiert werden, z.B. in eher spielerischer Form für Jugendliche oder sachlich nüchterner Form für Erwachsene. In einem Feldversuch wurden Daten von 100-Probanden erfasst. Zukünftig soll mit der SMART-iBrush Technologie, bei deren Entwicklung Wissenschaftler in den Bereichen Psychologie, Zahnmedizin, Embedded Systems und Machine Learning kooperieren, auch die Güte des Putzvorgangs bewertet werden, um die Putzenden aktiv anzuleiten. Intelligent toothbrush research (SMART-iBrush) aims to support humans in learning their individual, most effective tooth brushing technique. Therefore, a toothbrush was developed that measures motion and force applied to its tip. Measurements are transferred to a smart device where they can be visualized in real-time, for example in a more playful fashion for children or a-more factual fashion for adults. Field trials were conducted with 100 participants. Future features of SMART-iBrush 'will include interactive guidance and training techniques. To achieve these goals, researchers from the fields of psychology, dentistry, embedded systems, and machine learning cooperate in SMART-iBrush project. KW - Bewegungsmessung KW - Druckverlauf KW - Embedded-System KW - Erwachsener KW - Feldversuch KW - Jugendlicher KW - Kind KW - maschinelles Lernen KW - Psychologie KW - Zahnbürste KW - Zahnmedizin Y1 - 2014 SN - 978-3-86818-073-2 SP - 315 EP - 327 PB - Helmut-Schmidt-Universität, Universität der Bundeswehr CY - Hamburg ER - TY - JOUR A1 - Sydoruk, O. A1 - Shamonin (Chamonine), Mikhail A1 - Radkovskaya, Anna A. A1 - Zhuromskyy, Oleksandr A1 - Shamonina, Ekaterina A1 - Trautner, Ralph A1 - Stevens, C. J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Solymar, L. T1 - Mechanism of subwavelength imaging with bilayered magnetic metamaterials: Theory and experiment JF - Journal of Applied Physics N2 - We present a theoretical and experimental study of a bilayered metamaterial structure for subwavelength imaging of magnetic field. The simplest version of such a structure consists of one or two linear arrays of capacitively loaded split pipe resonators. Its subwavelength physics is governed by strongly anisotropic magnetic coupling between individual resonators and by propagation of magnetoinductive waves with wavelength much shorter than the wavelength of the electromagnetic radiation in free space. It is shown that magnetoinductive waves propagating in the lateral direction are undesirable because they spread the image. Good subwavelength imaging is achieved when, due to the strong interlayer coupling, a stop band in the vicinity of the resonant frequency appears in the dispersion characteristics. The imaging properties of the single and double lens are compared and it is shown that the double lens has a superior performance. Excellent agreement is obtained between experimental and theoretical results for the magnetic field in the image plane in the operation frequency range of 30–60 MHz. It is shown that the same mechanism is responsible for image formation using bilayered planar metamaterial structures and a design of such a lens comprising two planar layers with a total of 542 elements is provided. The conclusions are not restricted to the radio frequency region because the elements can be scaled down. Y1 - 2007 U6 - https://doi.org/10.1063/1.2714782 VL - 101 IS - 7 PB - AIP ER - TY - JOUR A1 - Hofrichter, Andreas A1 - Rank, Daniel A1 - Heberl, Michael A1 - Sterner, Michael T1 - Determination of the optimal power ratio between electrolysis and renewable energy to investigate the effects on the hydrogen production costs JF - International Journal of Hydrogen Energy N2 - Green hydrogen via renewable powered electrolysis has a high relevance in decarbonization and supply security. Achieving economically competitive hydrogen production costs is a major challenge in times of an energy price crisis. Our objective is to show the economically optimal installed capacity of electrolysers in relation to wind and solar power so swift and credible statements can be made regarding the system design. The ratio between renewable generation and electrolysis power as well as scaling effects, operating behaviour and development of costs are considered. Hydrogen production costs are calculated for four exemplary real PV and wind sites and different ratios of electrolysis to renewable power for the year 2020. The ideal ratio for PV systems is between 14% and 73% and for wind between 3.3% and 143% for low and high full load hours. The lowest hydrogen production costs are identified at 2.53 €/kg for 50 MW wind power and 72 MW electrolysis power. The results provide plant constructors the possibility to create a cost-optimized design via an optimum ratio of electrolysis to renewable capacity. Therefore, the procedures for planning and dimensioning of selected systems can be drastically simplified. Y1 - 2023 U6 - https://doi.org/10.1016/j.ijhydene.2022.09.263 SN - 0360-3199 N1 - Corresponding author: Michael Heberl N1 - Corrigendum to “Determination of the optimal power ratio between electrolysis and renewable energy to investigate the effects on the hydrogen production costs” [Int J Hydrogen Energy 48 (5) (2023) 1651–1663] - https://doi.org/10.1016/j.ijhydene.2023.03.128 VL - 48 IS - 5 SP - 1651 EP - 1663 PB - Elsevier ER - TY - JOUR A1 - Radkovskaya, Anna A. A1 - Sydoruk, O. A1 - Shamonin (Chamonine), Mikhail A1 - Stevens, C. J. A1 - Faulkner, Grahame A1 - Edwards, David J. A1 - Shamonina, Ekaterina A1 - Solymar, L. T1 - Transmission properties of two shifted magnetoinductive waveguides JF - Microwave and Optical Technology Letters N2 - Transmission properties of magnetoinductive waves propagating in two coupled one-dimensional metamaterial arrays are studied both experimentally and theoretically for the case when one of the arrays is shifted relative to the other one. Two different kinds of resonant metamaterial elements, split-pipe and spiral resonators, are investigated in the frequency bands centred at 46.2 and 586 MHz, respectively. It is shown that within a certain frequency range close to the resonant frequencies the transmission is strongly dependent on the shift. Theoretical calculations based on the impedance matrix show good agreement with the experimental results Y1 - 2007 U6 - https://doi.org/10.1002/mop.22344 VL - 49 IS - 5 SP - 997 EP - 1230 PB - Wiley ER - TY - CHAP A1 - De, Sangita A1 - Niklas, Michael A1 - Brada, Premek A1 - Mottok, Jürgen T1 - Model Transformation of Application Software Component from Classic to Adaptive AUTOSAR: An Approach to Migrate Software Components T2 - SEAA 2018, the 44th EUROMICRO Conference on Software Engineering and Advanced Applications, August 29 - 31 2018, Prague, Czech Republic Y1 - 2018 SN - 978-3-902457-50-9 ER - TY - CHAP A1 - Reindl, Andrea A1 - Lang, Andreas A1 - Niemetz, Michael A1 - Meier, Hans T1 - Switching and Averaging Models of a Bidirectional, Half-Bridge Based DC-DC converter with Load Distribution T2 - Proceedings of the 15th International Modelica Conference 2023, Aachen, October 9-11 N2 - Batteries are used in numerous applications such as mobile devices, electric vehicles, home storage systems and islanded microgrids. Bidirectional DC-DC converters are vital for the integration of batteries, for the power conversion during (dis)charge and the battery management. Modeling of these is helpful, especially for the design of larger, more complex systems consisting of multiple DC-DC converters in parallel. Due to the high switching frequencies, the simulation of DC-DC converters is associated with increased computational time and effort. In this paper, three models of different complexity and accuracy are proposed for a bidirectional DC-DC converter consisting of two phase-shifted half-bridges. Two switching models, which differ mainly in the way the mosfets are driven, account for the individual switching operations and exhibit high accuracy. An averaging model replaces the switching elements with current and voltage sources providing the mean values. It is particularly suitable for multiple components and longer simulation durations. The dynamic behavior of the models is analyzed using the step responses of the load current. For validation, these are compared with the theoretical transfer function. The three models are analyzed comparatively in terms of computational time and effort. The calculation time of the averaging model has been reduced by two thirds compared to the strictly complementary switching model and by 96% relative to the model with diode emulation mode. The averaging model requires only one third of the computation time of the complementary switching model and only 3.5% of that of the model with diode emulation. Recommendations for the use of the models are given and a possible use case is shown. Two parallel connected DC-DC converters with load current sharing between them are simulated using the averaging model. KW - Bidirectional DC/DC Converter KW - Averaging Model KW - Switching Model KW - Computational Effort KW - Modelica KW - Half Bridge KW - Circuit Averaging Y1 - 2023 U6 - https://doi.org/10.3384/ecp204683 PB - OJS ER - TY - CHAP A1 - Bugert, Flemming A1 - Staufer, Susanne A1 - Bittner, Dominik A1 - Nadimpalli, Vamsi Krishna A1 - Ezer, Timur A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Mottok, Jürgen T1 - Ariadne's Thread for Unravelling Learning Paths: Identifying Learning Styles via Hidden Markov Models T2 - 2024 IEEE Global Engineering Education Conference (EDUCON), 08-11 May 2024, Kos Island, Greece N2 - Modern education through Learning Management Systems (LMSs) provides learners with personalized learning paths. This is achieved by first querying the learning style according to the theory of Felder and Silverman to recommend suitable learning content. However, a rigid learning style representation is lacking of adaptability to the learners' choices. Therefore, the present study evaluates the idea of providing adaption to the representation of learning styles by using Hidden Markov Models (HMMs). Thus, data is collected from participants out of the Higher Education Area. The Index of Learning Styles questionnaire is used to obtain the learning style based on the theory of Felder and Silverman. Also, a questionnaire that asks the respondents to create a preferred learning path with the sequence length of nine learning elements is provided. From the given data, we initially evaluate the probability relationships between learning styles and learning elements. Then, we use the Viterbi algorithm in HMMs to identify alterations in learning styles from the provided learning paths. The alignment is then quantified by introducing a metric called support value. The findings imply that our concept can be used to adapt the learning style based on the user's real choice of learning elements. Thus, the proposed model also offers a way to integrate a feedback loop within LMSs leading to an improvement of learning path recommendation algorithms. KW - Surveys KW - Knowledge engineering KW - Feedback loop KW - Learning management systems KW - Uncertainty KW - Viterbi algorithm Y1 - 2024 U6 - https://doi.org/10.1109/EDUCON60312.2024.10578825 SN - 2165-9567 SP - 1 EP - 7 PB - IEEE ER - TY - GEN A1 - Chavez Vega, Jhohan Harvey A1 - Böhm, Valter A1 - Yin, J. A1 - Becker, Tatiana I. A1 - Köhring, Sebastian A1 - Monkman, Gareth J. A1 - Odenbach, Stefan A1 - Zimmermann, Klaus T1 - Field induced plasticity of magneto-sensitive elastomers for gripping technology applications T2 - 6th Colloquium of SPP 1681, Benediktbeuern, 26. - 28.09.2018 : Book of Abstracts Y1 - 2018 SP - 16 EP - 17 ER - TY - CHAP A1 - Sehr, Armin A1 - Yoshioka, Takuya A1 - Delcroix, Marc A1 - Kinoshita, Keisuke A1 - Nakatani, Tomohiro A1 - Maas, Roland A1 - Kellermann, Walter T1 - Conditional emission densities for combining speech enhancement and recognition systems T2 - Proceedings of the Annual Conference of the International Speech Communication Association, INTERSPEECH, 25 - 29 August 2013, Lyon, France N2 - A novel framework based on conditional emission densities for hidden Markov models (HMMs) is proposed in this contribution to integrate speech enhancement systems with automatic speech recognition systems. In the training phase, the observed feature vectors, corrupted by background noise and reverberation, together with estimates for the interference as provided by the speech enhancement system are used for training joint densities of the observations and the interference estimates. In the decoding phase, the joint densities are transformed to conditional densities of the observed features given the interference estimates. Thus, front end processing can be exploited for obtaining interference estimates, and the estimation errors can be modeled very effectively in a data-driven way. Connected digit recognition experiments in a simulated reverberant environment show the potential of the proposed approach: HMMs with the proposed conditional densities outperform various configurations of conventional HMMs in the logarithmic melspectral domain. This is a first step towards using conditional densities for creating synergies between front end and back end. Index Terms: speech enhancement, robust speech recognition, dereverberation, conditional HMM emission densities, frame- by-frame model adaptation. Y1 - 2013 U6 - https://doi.org/10.21437/Interspeech.2013-265 SP - 3502 EP - 3506 PB - ISCA ER - TY - CHAP A1 - Drexler, C. A1 - Hirmer, Marion A1 - Danilov, Sergey N. A1 - Giglberger, Stephan A1 - Putzger, Jürgen A1 - Niklas, Andreas A1 - Jäger, Andreas A1 - Hiller, Karl-Anton A1 - Löffler, S. A1 - Schmalz, Gottfried A1 - Redlich, Britta A1 - Schulz, Irene A1 - Monkman, Gareth J. A1 - Ganichev, Sergey D. T1 - Infrared spectroscopy for clinical diagnosis of dental pulp vitality T2 - 37th International Conference on Infrared, Millimetre, and Terahertz Waves (IRMMW-THz 37), 23-28 September 2012 , Wollongong, Australia N2 - Transmission spectra of wet human teeth and dentin slices, together with blood of different flow rates were investigated over a wide spectral range, from visible to terahertz (THz) light. The results make it possible to find the optimum light frequency for an all-optical determination of pulpal blood flow and, consequently, for clinically diagnosis of tooth vitality. Y1 - 2012 U6 - https://doi.org/10.1109/IRMMW-THz.2012.6380091 PB - IEEE CY - Piscataway, NJ ER - TY - CHAP A1 - Forster, Eva A1 - Rabindranath, Raman A1 - Mayer, Matthias A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Characterization of ultra soft Magneto-Active Polymers (MAPs) T2 - Conference proceedings / INDUCTICA 2011, Berlin, Germany, 24 - 26 May Y1 - 2011 ER - TY - CHAP A1 - Nerlich, Michael A1 - Monkman, Gareth J. A1 - Füchtmeier, Bernd A1 - Egersdörfer, Stefan T1 - Development of a Robotic Navigation and Fracture Fixation System T2 - 1. Jahrestagung der Deutschen Gesellschaft für Computer- und Roboterassistierte Chirurgie (CURAC), Leipzig, 2002 Y1 - 2002 ER - TY - CHAP A1 - Gärtner, Sebastian A1 - Rank, Daniel A1 - Heberl, Michael A1 - Gaderer, Matthias A1 - Sterner, Michael T1 - Integration of Power-To-Methane into Glass Melting Processes T2 - Proceedings of the International Renewable Energy Storage Conference (IRES 2022) N2 - The glass industry is facing increased challenges regarding climate protection targets and rising energy costs. The integration of renewable energy including conversion and storage is a key for both challenges in this energy-intensive industrial sector, which has been mainly relying on fossil gas so far. The options considered to this point for reducing CO2 emissions and switching to a renewable energy supply involve far-reaching changes of the established melting processes. This entails significant risks in terms of influences on glass quality and stable production volumes. The presented approach for the integration of a Power-to-Methane (PtM) system into the glass industry is a completely new concept and has not been considered in detail before. It allows the use of established oxyfuel melting processes, the integration of fluctuating renewable energy sources and a simultaneous reduction of CO2 emissions by more than 78%. At the same time, natural gas purchases become obsolete. A techno-economic evaluation of the complete PtM process shows, that 1,76 €/m3 or 1,26 €/kg synthetic natural gas are possible with renewable energy supply. Using electricity from the energy grid would require electricity prices < 0,126 €/kWh to allow cost competitive PtM processes in the glass industry. Such electricity prices could be achieved by electricity market-based optimization and operation of the PtM system. This operation strategy would require AI-based algorithms predicting availabilities and prices on future-based markets. KW - Power-to-Gas KW - Methanation KW - Glass Melting KW - Glass Industry KW - Decarbonisation Y1 - 2023 U6 - https://doi.org/10.2991/978-94-6463-156-2_12 SN - 2589-4943 VL - 16 SP - 147 EP - 161 PB - Atlantis Press ER - TY - CHAP A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Mottok, Jürgen A1 - Jahn, Sabrina A1 - Nadimpalli, Vamsi Krishna T1 - The Expert’s View: Eye Movement Modeling Examples in Software Engineering Education T2 - Proceedings of the 5th European Conference on Software Engineering Education, Seeon/Germany, June 19 - 21, 2023 N2 - This study investigates the impact of eye movement modeling examples in Software Engineering education. Software Engineering is a highly visual domain. The daily tasks of a software engineer (e.g., formulating requirements, creating UML diagrams, or conducting a code review) require in many cases the use of certain visual strategies. Although these strategies can be found for experts, it has been observed in different eye tracking studies that students have difficulties in learning and applying them. To familiarize students with these visual strategies and to provide them with a better understanding for the cognitive processes involved, a total of seven eye movement modeling examples was created. The seven eye movement modeling examples cover relevant parts of an introductory Software Engineering lecture; they are focused on typical situations in which visual strategies are applied. The results of a questionnaire-based evaluation shows that students consider the eye movement modeling examples as useful, feel supported in their learning process, and would like to see more use of them in the Software Engineering lecture. Furthermore, the students suggested that eye movement modeling examples should also be used in other lectures. Y1 - 2023 SN - 978-1-4503-9956-2 U6 - https://doi.org/10.1145/3593663.3593683 SP - 148 EP - 152 PB - ACM ER - TY - CHAP A1 - Bugert, Flemming A1 - Grabinger, Lisa A1 - Bittner, Dominik A1 - Hauser, Florian A1 - Nadimpalli, Vamsi Krishna A1 - Staufer, Susanne A1 - Mottok, Jürgen T1 - Towards Learning Style Prediction based on Personality T2 - Proceedings of the 5th European Conference on Software Engineering Education, Seeon/Germany, June 19 - 21, 2023 N2 - This paper assesses the relation between personality, demographics, and learning style. Hence, data is collected from 200 participants using 1) the BFI-10 to obtain the participant’s expression of personality traits according to the five-factor model, 2) the ILS to determine the participant’s learning style according to Felder and Silverman, and 3) a demographic questionnaire. From the obtained data, we train and evaluate a Bayesian network. Using Bayesian statistics, we show that age and gender slightly influence personality and that demographics as well as personality have at least a minor effect on learning styles. We also discuss the limitations and future work of the presented approach. Y1 - 2023 SN - 978-1-4503-9956-2 U6 - https://doi.org/10.1145/3593663.3593682 SP - 48 EP - 55 PB - ACM ER - TY - CHAP A1 - Bittner, Dominik A1 - Hauser, Florian A1 - Nadimpalli, Vamsi Krishna A1 - Grabinger, Lisa A1 - Staufer, Susanne A1 - Mottok, Jürgen T1 - Towards Eye Tracking based Learning Style Identification T2 - Proceedings of the 5th European Conference on Software Engineering Education, Seeon/Germany, June 19 - 21, 2023 N2 - The dropout rate at universities has been very high for years. Thereby, the inexperience and lack of knowledge of students in dealing with individual learning paths in various courses of study plays a decisive role. Adaptive learning management systems are suitable countermeasures, in which learners’ learning styles are classified using questionnaires or computationally intensive algorithms before a learning path is suggested accordingly. In this paper, a study design for student learning style classification using eye tracking is presented. Furthermore, qualitative and quantitative analyses clarify certain relationships between students’ eye movements and learning styles. With the help of classification based on eye tracking, the filling out of questionnaires or the integration of computationally or cost-intensive algorithms can be made redundant in the future. Y1 - 2023 SN - 978-1-4503-9956-2 U6 - https://doi.org/10.1145/3593663.3593680 SP - 138 EP - 147 PB - ACM ER - TY - CHAP A1 - Nadimpalli, Vamsi Krishna A1 - Bugert, Flemming A1 - Bittner, Dominik A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Staufer, Susanne A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - Towards personalized learning paths in adaptive learning management systems: bayesian modelling of psychological theories T2 - Proceedings of the 16th annual International Conference of Education, Research and Innovation (ICERI 2023), Seville, Spain, 11/13/2023 - 11/14/2023 N2 - In educational research, non-personalized learning content increases learners' cognitive load, causing them to lower their performance and sometimes drop out of the course. Personalizing learning content with learners’ unique characteristics, like learning styles, personality traits, and learning strategies, is being suggested to improve learners’ success. Several theories exist for assessing learners’ unique characteristics. By the end of 2020, 71 learning style theories have been formulated, and research has shown that combining multiple learning style theories to recommend learning paths yields better results. As of the end of 2022, there is no single research that demonstrates a relationship between the Index of Learning Styles (ILS) based Felder-Silverman learning style model (FSLSM) dimensions, Big Five (BFI-10) based personality traits, and the Learning strategies in studying (LIST-K) based learning strategies factors for personalizing learning content. In this paper, an innovative approach is proposed to estimate the relationship between these theories and map the corresponding learning elements to create personalized learning paths. Respective questionnaires were distributed to 297 higher education students for data collection. A three-step approach was formulated to estimate the relationship between the models. First, a literature search was conducted to find existing studies. Then, an expert interview was carried out with a group of one software engineering education research professor, three doctoral students, and two master’s students. Finally, the correlations between the students' questionnaire responses were calculated. To achieve this, a Bayesian Network was built with expert knowledge from the three-step approach, and the weights were learned from collected data. The probability of individual FSLSM learning style dimensions was estimated for a new test sample. Based on the literature, the learning elements were mapped to the respective FSLSM learning style dimensions and were initiated as learning paths to the learners. The next steps are proposed to extend this framework and dynamically recommend learning paths in real time. In addition, the individual levels of learning style dimensions, personality traits, and learning strategies can be considered to improve the recommendations. Further, using probabilities for mapping learning elements to learning styles can increase the chance of initiating multiple learning paths for an individual learner. Y1 - 2023 U6 - https://doi.org/10.21125/iceri.2023.1144 SP - 4593 EP - 4603 PB - IATED ER - TY - CHAP A1 - Tremmel, Florian A1 - Nagler, Oliver A1 - Kutter, Christoph A1 - Holmer, Rainer T1 - Smart Cantilever Probe with Integrated Force and Acoustic Emission Sensor T2 - 2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023 N2 - Acoustic emission (AE) testing recently found its application in the wafer testing sector of the semiconductor industry. To find out the mechanical robustness of semiconductor devices, contact pads on the chip surface are intentionally overstressed with an indenter tip and the appearing oxide cracks are detected with help of the generated AE signals. This is done in a customized test bench with a patented sensor-indenter system. This paper presents an improved version of the measurement setup that solves certain disadvantages of it and can be used in a standard wafer prober. The main components of the developed sensor system are a strain gauge for contact force measurement and a piezoelectric sensor element for AE signal detection. Both components are integrated on a cantilever beam which has an exchangeable indenter tip at its free end. The cantilever probe is electrically conductive to enable electrical tests via the indenter tip. This smart sensor-cantilever combination (SCC) can be mounted with several adapter components on a carrier plate to place it in a wafer prober. For both sensor elements amplifier circuits are developed to enhance their signal-to-noise ratios (SNRs). A prototype setup is shown together with simulated and experimental results to demonstrate its performance. The mechanical properties of the cantilever, as well as the force sensor and the AE crack signals, already fulfill the requirements for an implementation in a wafer prober. To further improve the sensor resolutions and detection limits, several optimizations regarding the design of the SCC are in progress. KW - Acoustic emission testing KW - piezoelectric sensor KW - strain gauge KW - operational amplifier circuit Y1 - 2023 SN - 979-8-3503-0387-2 U6 - https://doi.org/10.1109/SENSORS56945.2023.10325021 SP - 1 EP - 4 PB - IEEE ER - TY - INPR A1 - Heberl, Michael A1 - Withelm, Christian A1 - Kaul, Anja A1 - Rank, Daniel A1 - Sterner, Michael T1 - Prospective Life Cycle Assessment of Biological Methanation in a Trickle-Bed Pilot Plant and a Potential Scale-Up N2 - In this study, a pilot-scale trickle-bed reactor for biological methanation and various scale-up scenarios for 2023 and 2050 were investigated using LCA. A best- and worst-case scenario for technology development until 2050 was evolved using cross consistency analysis and morphological field, based on which the data for the ecological models were determined.The results show that the plant scale-up has a very positive effect on the ecological consequences of methanation. In the best-case scenario, the values are a factor of 23-780 lower than those of the actual plant today. A hot-spot analysis showed that especially electrolysis operation has a large impact on total emissions. The final Monte-Carlo simulation shows that the technology is likely to achieve a low GWP with a median of 104.0 kg CO2-eq / MWh CH4. Y1 - 2023 U6 - https://doi.org/10.2139/ssrn.4635066 N1 - Der Aufsatz wurde peer-reviewd veröffentlich und ist ebenfalls in diesem Repositorium verzeichnet unter: https://opus4.kobv.de/opus4-oth-regensburg/frontdoor/index/index/docId/7349 PB - SSRN ER - TY - CHAP A1 - Ezer, Timur A1 - Plößl, Moritz A1 - Grabinger, Lisa A1 - Bittner, Dominik A1 - Staufer, Susanne A1 - Nadimpalli, Vamsi Krishna A1 - Bugert, Flemming A1 - Hauser, Florian A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - Deep learning for eye movement classification T2 - ICERI 2024 Proceedings, 17th annual International Conference of Education, Research and Innovation,11-13 November, 2024, Seville, Spain Y1 - 2024 U6 - https://doi.org/10.21125/iceri.2024.1028 SP - 4056 EP - 4065 PB - IATED ER - TY - INPR A1 - Gaube, Susanne A1 - Jussupow, Ekaterina A1 - Kokje, Eesha A1 - Khan, Jowaria A1 - Bondi-Kelly, Elizabeth A1 - Schicho, Andreas A1 - Kitamura, Felipe Campos A1 - Koch, Timo Kevin A1 - Ezer, Timur A1 - Mottok, Jürgen A1 - Lermer, Eva A1 - Ghassemi, Marzyeh A1 - Colak, Errol T1 - Underreliance Harms Human-AI Collaboration More Than Overreliance in Medical Imaging N2 - Importance: The use of artificial intelligence (AI) to support clinicians in diagnostic decision-making holds significant potential; however, evidence regarding its clinical utility remains mixed. In many cases, the interaction between healthcare professionals and AI systems does not improve collaborative performance compared to the standalone performance of humans or AI. Currently, the underlying mechanisms that limit human-AI collaboration are poorly understood. Objective: To examine the impact of AI advice on diagnostic decision-making among experts and novices, focusing on understanding the role of explainability (XAI) on users’ reliance on advice. Design, Setting, and Participants: A mixed-methods design combining a crossover experimental design with a think-aloud and an eye-tracking study arm was conducted in 2023. Participants were task experts (radiologists) and novices (non-radiologist physicians and medical trainees) from 10 countries, with the think-aloud and eye-tracking conducted in Germany. Intervention: Participants reviewed 50 patient cases containing head CT scans and patient information. Every case was reviewed in three time-separate sessions in randomized order. In each session, participants were exposed to a different experimental condition: (a) control, i.e., no AI prediction presented; (b) basic advice, i.e., AI prediction without annotations; and (c) XAI advice, i.e., AI prediction with annotations. For each case, participants had to determine if the patients had an intracranial hemorrhage (ICH), rate their confidence, and, if applicable, the usefulness of the AI advice. Main Outcome(s) and Measure(s): Diagnostic performance, confidence in the diagnosis, case reading time, and AI advice usefulness ratings. Results: The data analysis included 125 participants. The mean age was 28.5 years (SD = 6.72), and 55.2% identified as female. Underreliance on correct AI advice was associated with high uncertainty and had a more detrimental impact on diagnostic performance than overreliance on incorrect advice. XAI advice reduced underreliance and improved performance and confidence, particularly when reviewing more difficult cases with ICH. AI advice, particularly XAI, did not reduce reading time. XAI was perceived as more useful than basic AI advice, especially among novices. Conclusions and Relevance: Our findings indicate that underreliance on AI might be more harmful than overreliance, highlighting the need to develop efficient counterstrategies beyond current XAI methods. Y1 - 2024 U6 - https://doi.org/10.31219/osf.io/4wv8j PB - OSFPreprints ER - TY - CHAP A1 - Bittner, Dominik A1 - Hauser, Florian A1 - Engl, Fabian A1 - Mottok, Jürgen ED - Mottok, Jürgen ED - Hagel, Georg T1 - Eye Movement Modelling Examples on Usability Heuristics T2 - Proceedings of the 6th European Conference on Software Engineering Education : ECSEE 2025, Seeon Germany, June 02-04, 2025 N2 - The user interface (UI) and user experience (UX) design is of crucial importance for human-computer interaction (HCI), particularly in the context of web applications. In light of the high expectations of users and the competitive nature of the market, it is imperative to employ usability measurement techniques to avoid losing users. Heuristic evaluation (HE) is a cost- and resource-efficient method for evaluating the usability of websites in which evaluators are guided by heuristics. However, the level of expertise of the evaluators has a significant impact on the results, with experts identifying up to 50% more usability issues than novices. To address this gap, this paper proposes Eye Movement Modeling Examples (EMMEs) to demonstrate Jakob Nielsen’s ten usability heuristics in an easy-to-understand format for all levels of experience while also incorporating expert knowledge. In particular, the eye movements and verbal feedback of a usability expert are recorded as the expert analyses the usability of a simple website application in terms of Jakob Nielsen’s ten usability heuristics. This reveals the strategies and cognitive processes of the expert when assessing the usability of a website and makes them more tangible for non-experts or novices. The findings of a questionnaire-based assessment indicate that EMMEs are perceived as beneficial and supportive during the learning process. Ultimately, this comprehensive analysis not only enables a deeper understanding of heuristics for usability novices, but could also lead to EMMEs being applied more efficiently in diverse domains. Y1 - 2025 SN - 9798400712821 U6 - https://doi.org/10.1145/3723010.3723035 SP - 106 EP - 114 PB - ACM ER - TY - INPR A1 - Meisinger, Alexander A1 - Hofrichter, Andreas A1 - Bauer, Franz A1 - Sterner, Michael T1 - Unlocking Potential Energy Partnerships in Europe: a Case Study on the Way to a Franco-German Energy Transition N2 - Global warming is already causing global destabilization. Geopolitical challenges fuel this instability and highlight the need for trusted energy partnerships to ensure energy security. To limit global warming and increase energy security, it is essential to take joint action on an international and global scale. The European Green Deal contributes to this. However, specific national actions are still needed. This research presents a way forward for a Franco-German energy transition and unlocks the potential of energy partnerships within Europe, using a cost-based, sector-coupled optimization model. Both countries are coupled via an isolated country optimization approach. Thus, the focus is on the development of each national energy system. The results highlight the increase of energy security in line with the European Green Deal. The main pillars of the energy transition are solar energy (32- 33%), wind energy (25-38%) and biogenic energy sources (13-27%). Nuclear power is being phased out in Germany and France. The results show that a Franco-German energy partnership has great potential. Overall, France can cost-effectively cover 25% of Germany’s hydrogen import needs (122 TWh) in 2050. At the same time, France can also benefit from the energy partnership in terms of economic growth and joint action to mitigate climate crisis. KW - Decarbonization KW - Energy partnership KW - Energy system modelling KW - Energy transition KW - European Green Deal KW - Power-to-X Y1 - 2025 U6 - https://doi.org/10.2139/ssrn.5251699 PB - SSRN ER - TY - JOUR A1 - Savelev, Dmitrii V. A1 - Glavan, Gašper A1 - Belan, Viktoria O. A1 - Belyaeva, Inna A. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Resonant Magnetoelectric Effect at Low Frequencies in Layered Polymeric Cantilevers Containing a Magnetoactive Elastomer JF - Applied Sciences N2 - In this work, the resonance enhancement of magnetoelectric (ME) coupling at the two lowest bending resonance frequencies was investigated in layered cantilever structures comprising a magnetoactive elastomer (MAE) slab and a commercially available piezoelectric polymer multilayer. A cantilever was fixed at one end in the horizontal plane and the magnetic field was applied horizontally. Five composite structures, each containing an MAE layer of different thicknesses from 0.85 to 4 mm, were fabricated. The fundamental bending resonance frequency in the absence of a magnetic field varied between roughly 23 and 55 Hz. It decreased with the increasing thickness of the MAE layer, which was explained by a simple theory. The largest ME voltage coefficient of about 7.85 V/A was measured in a sample where the thickness of the MAE layer was ≈2 mm. A significant increase in the bending resonance frequencies in the applied DC magnetic field of 240 kA/m up to 200% was observed. The results were compared with alternative designs for layered multiferroic structures. Directions for future research were also discussed. KW - flexible composite KW - low frequency KW - magnetoactive elastomer KW - magnetoelectric effect KW - piezoelectric polymer Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-30637 N1 - corresponding authors: Dmitry V. Saveliev and Mikhail Shamonin VL - 12 IS - 4 SP - 1 EP - 13 PB - MPDI ER - TY - RPRT A1 - Marschall, Felix T1 - HEKATE - Implementierung eines Dashboards zur Visualisierung von Auswertungen des HASKI Konzepts für einen umfassenden Einblick in den Lernprozess BT - Projektarbeit N2 - In der gegenwärtigen Bildungslandschaft erfährt die adaptive Hochschullehre eine zunehmende Relevanz, da traditionelle Lehrmethoden vielfach nicht mehr hinreichend sind, um den individuellen Bedürfnissen der Studierenden zu entsprechen. Das Projekt HEKATE zielt darauf ab, die Erkenntnisse aus dem HASKI-System, einem innovativen Ansatz für personalisierte Lernunterstützung basierend auf KI und maschinellem Lernen, effektiv zu visualisieren. HEKATE ergänzt das HASKI-System durch die Entwicklung eines Dashboards, welches eine transparente und nachvollziehbare Darstellung der Lernstildaten ermöglicht. Das Ziel des Projekts besteht in der Umsetzung einer Visualisierungslösung, die sich durch eine hohe Benutzerfreundlichkeit sowie Leistungsfähigkeit auszeichnet und alle relevanten Lern- und Nutzungsdaten Studierender adäquat abbildet. Die funktionalen Anforderungen umfassten die präzise Darstellung von Lernstil-Ergebnissen, Quiz- und Übungsergebnissen sowie die Integration des ARIADNE-Konzepts. Des Weiteren werden nichtfunktionale Ziele definiert, welche eine hohe Benutzerfreundlichkeit, Systemsicherheit, kurze Ladezeiten sowie eine verlässliche Datenverarbeitung umfassten. Hekate bietet sowohl für Studierende als auch für Lehrende einen erheblichen Mehrwert, indem es Lern- und Nutzungsmuster auf einfache und intuitive Weise visualisiert. Die Integration in die HASKI-Umgebung und Moodle gewährleistet eine nahtlose Einbindung der Anwendung in bestehende Lernumgebungen, wodurch sich der Nutzen weiter steigert. In künftigen Entwicklungsstufen könnten zusätzliche Visualisierungsoptionen und Funktionen integriert werden, um das System weiter zu optimieren und an die Bedürfnisse der Nutzer anzupassen. N2 - In the current educational landscape, adaptive university teaching is becoming increasingly relevant, as traditional teaching methods are often no longer sufficient to meet the individual needs of students. The HEKATE project aims to effectively visualise the findings from the HASKI system, an innovative approach to personalised learning support based on AI and machine learning. HEKATE complements the HASKI system by developing a dashboard that enables a transparent and comprehensible visualisation of learning style data. The aim of the project is to implement a visualisation solution that is characterised by a high level of user-friendliness and performance and adequately depicts all relevant learning and usage data of students. The functional requirements included the precise visualisation of learning style results, quiz and exercise results as well as the integration of the ARIADNE concept. Non-functional goals were also defined, which included a high level of user-friendliness, system security, short loading times and reliable data processing. Hekate offers significant added value for both students and teachers by visualising learning and usage patterns in a simple and intuitive way. The integration into the HASKI environment and Moodle ensures a seamless integration of the application into existing learning environments, which further increases the benefits. In future development stages, additional visualisation options and functions could be integrated in order to further optimise the system and adapt it to the needs of users. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-79221 PB - Regensburg ER - TY - CHAP A1 - Hauser, Florian A1 - Staufer, Susanne A1 - Grabinger, Lisa A1 - Röhrl, Simon A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - On the analysis of student learning strategies: using the LIST-K questionnaire ro generate ai-based individualized learning paths T2 - Proceedings of the 16th annual International Conference of Education, Research and Innovation (ICERI 2023), Seville, Spain, 11/13/2023 - 11/14/2023 N2 - This paper presents the results of a data collection with the LIST-K questionnaire. This questionnaire measures students’ learning strategies and shows which strategies are particularly dominant or rather weak. Learning strategies have long been a major area of research in educational science and psychology. In these disciplines, learning strategies are understood as intentional behaviors and cognitive skills that learners employ to effectively complete learning tasks, by selecting, acquiring, organizing, and integrating information into their existing knowledge for long-term retention. The LIST-K, developed by Klingsieck in 2018, was chosen for accessing learning strategies due to its thematic suitability, widespread use, and test economy. It covers a total of four main categories (i.e., cognitive strategies, metacognitive strategies, management of internal resources, and management of external resources), each of which are subdivided into further subscales. With a total of 39 items answered via a 5-step Likert scale, the LIST-K can cover the topic relatively comprehensively and at the same time be completed in a reasonable amount of time of approximately 10 minutes. The LIST-K was used as part of a combined data collection along with other questionnaires on their personal data, their preferences regarding certain learning elements, their learning style (i.e. the ILS), and personality (i.e. the BFI-10). A total of 207 students from different study programs participated via an online survey created using the survey tool "LimeSurvey". Participation in the study was voluntary, anonymously, and in compliance with the GDPR. Overall, the results of the LIST-K show that students are willing to work intensively on relevant topics intensively and to perform beyond the requirements of the course seeking additional learning material. At the same time, however, it is apparent that the organization of their own learning process could still be improved. For example, students start repeating content too late (mean=2.70; SD=0.92) and do not set goals for themselves and do not create a learning plan (mean=3.19; SD=0.90). They also learn without a schedule (mean=2.23; SD=0.97) and miss opportunities to learn together with other students (mean=3.17; SD=0.94). The findings of the data collection will be used to create an AI-based adaptive learning management system that will create individualized learning paths for students in their respective courses. From the results of the LIST-K, it appears that the adaptive learning management system should primarily support organizational aspects of student learning. Even small impulses (an individual schedule of when to learn what or a hierarchical structuring of the learning material) could help students to complete their courses more successfully and improve their learning. Y1 - 2023 U6 - https://doi.org/10.21125/iceri.2023.1147 SP - 4611 EP - 4620 PB - IATED ER - TY - JOUR A1 - Fetisov, Yuri K. A1 - Chashin, Dmitri V. A1 - Savelev, Dmitrii V. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Anisotropic Magnetoelectric Effect in a Planar Heterostructure Comprising Piezoelectric Ceramics and Magnetostrictive Fibrous Composite JF - Materials N2 - The direct magnetoelectric (ME) effect is investigated in a planar structure comprising mechanically coupled layers of a magnetostrictive fibrous composite (MFC) and a piezoelectric ceramics (lead zirconate titanate, PZT). The MFC is an array of Ni-wires with a diameter of 200 mu m that are aligned parallel to each other in a single layer. The wires are separated by a distance of 250 or 500 mu m and fixed in a polyamide matrix. The structure was placed in a tangential constant field H and was excited by an alternating magnetic field h parallel to H, while the voltage generated by the PZT layer was measured. The resulting field dependences of the magnetization M(H) and the magnetostriction lambda(H) were determined by the orientation of the field H in the plane of the structure and the distance between the Ni-wires. The ME coupling coefficient of the structure decreased from 4.8 to 0.25 V/A when the orientation of H was changed from parallel to perpendicular to Ni-wires. With an increase in the excitation field amplitude h, a nonlinear ME effect in the output voltage, namely frequency doubling, was observed. The frequency and field dependences of the efficiency of the ME transduction in the MFC-piezoelectric heterostructure are well described by the existing theory. KW - composite KW - frequency doubling KW - heterostructure KW - magnetoelectric effect KW - magnetostrictive fiber KW - piezoelectric ceramic material Y1 - 2019 U6 - https://doi.org/10.3390/ma12193228 N1 - Corresponding authors: Yuri Fetisov, Mikhail Shamonin VL - 12 IS - 19 SP - 1 EP - 13 PB - MDPI CY - Basel ER - TY - RPRT A1 - Rabindranath, Raman A1 - Böse, Holger A1 - Probst, Jörn A1 - Schlunck, Günther A1 - Mayer, Matthias A1 - Forster, Eva A1 - Bentz, Alexander A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - EAP mit magnetisch steuerbarer Elastizität zur Interaktion mit Bindegewebszellen MagElan BT - Teilvorhaben (HS-Regensburg) "Etablierung eines mechatronischen Systems zur (Magneto) Elastophorese von Bindegewebszellen" ; Schlussbericht ; Verbundprojekt "MagElan" ; Laufzeit des Vorhabens: 01.07.2009 - 30.10.2011 Y1 - 2012 N1 - Förderkennzeichen BMBF 13N10574 CY - Regensburg ER - TY - JOUR A1 - Savelev, Dmitrii V. A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail A1 - Fetisov, Yuri K. T1 - Ceramic-Heterostructure-Based Magnetoelectric Voltage Transformer with an Adjustable Transformation Ratio JF - Materials N2 - A voltage transformer employing the magnetoelectric effect in a composite ceramic heterostructure with layers of a magnetostrictive nickel–cobalt ferrite and a piezoelectric lead zirconate–titanate is described. In contrast to electromagnetic and piezoelectric transformers, a unique feature of the presented transformer is the possibility of tuning the voltage transformation ratio K using a dc magnetic field. The dependences of the transformer characteristics on the frequency and the amplitude of the input voltage, the strength of the control magnetic field and the load resistance are investigated. The transformer operates in the voltage range between 0 and 112 V, and the voltage transformation ratio K is tuned between 0 and 14.1 when the control field H changes between 0 and 6.4 kA/m. The power at the transformer output reached 63 mW, and the power conversion efficiency was 34%. The methods for calculation of the frequency response, and the field and load characteristics of the transformer are proposed. The ways to improve performance characteristics of magnetoelectric transformers and their possible application areas are discussed. KW - magnetoelectric effect KW - piezoelectric effect KW - voltage transformer KW - composite material KW - magnetostriction Y1 - 2020 U6 - https://doi.org/10.3390/ma13183981 VL - 13 IS - 18 SP - 1 EP - 13 PB - MDPI ER - TY - JOUR A1 - Romeis, Dirk A1 - Kostrov, Sergei A. A1 - Kramarenko, Elena Yu A1 - Stepanov, Gennady V. A1 - Shamonin (Chamonine), Mikhail A1 - Saphiannikova, Marina T1 - Magnetic-field-induced stress in confined magnetoactive elastomers JF - Soft Matter N2 - We present a theoretical approach for calculating the state of stress induced by a uniform magnetic field in confined magnetoactive elastomers of arbitrary shape. The theory explicitly includes the magnetic field generated by magnetizable spherical inclusions in the sample interior assuming a non-linear magnetization behavior. The initial spatial distribution of particles and its change in an external magnetic field are considered. This is achieved by the introduction of an effective demagnetizing factor where both the sample shape and the material microstructure are taken into account. Theoretical predictions are fitted to the stress data measured using a specifically designed experimental setup. It is shown that the theory enables the quantification of the effect of material microstructure upon introducing a specific microstructural factor and its derivative with respect to the extensional strain in the undeformed state. The experimentally observed differences between isotropic and anisotropic samples, compliant and stiff elastomer matrices are explained. Y1 - 2020 U6 - https://doi.org/10.1039/D0SM01337D VL - 16 IS - 39 SP - 9047 EP - 9058 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Yuskevich, Pavel A1 - Savelev, Dmitrii V. A1 - Belyaeva, Inna A. T1 - Induced anisotropy in composite materials with reconfigurable microstructure: Effective medium model with movable percolation threshold JF - Physica A: Statistical Mechanics and its Applications N2 - In composite materials, with field-dependent restructuring of the filler material (changes in the mutual arrangement of inclusions), the presence of an external magnetic field induces anisotropy of the dielectric properties, even if the composite is isotropic in the absence of an external field. A modified effective medium approximation is proposed for the calculation of the components of effective permittivity within a class of composites with reconfigurable microstructure, where both phases (the filler and the matrix) are isotropic and the inclusions have spherical shape. The effective physical properties are calculated in the parallel and perpendicular directions to an applied field. The appearance of the anisotropy of the permittivity is simulated by the introduction of two not-equal, possibly variable (field-dependent) percolation thresholds. The implications, of the proposed theoretical approach, are demonstrated for the case of the dielectric properties of magnetoactive elastomers (MAEs). In MAEs with soft polymer matrices, the mutual arrangement of micrometer-sized magnetic inclusions can significantly change in an applied magnetic field. A reasonable agreement between theory and experiment at a measurement frequency of 1 kHz is found, and is improved in comparison to the previous models. The components of the effective permittivity tensor, characterizing the dielectric properties along the direction of the applied magnetic field and in the orthogonal direction, grow with an increasing field. This growth is more pronounced for the permittivity component in the field direction. The possible extensions of the theoretical model and future directions of research are discussed. The presented theoretical approach can be useful for the application-driven development of a number of smart materials, in particular electro- and magnetorheological gels, elastomers and fluids. KW - Effective medium theory KW - Magnetoactive elastomer KW - Percolation threshold KW - Anisotropy KW - Effective permittivity KW - Random heterogeneous medium Y1 - 2020 U6 - https://doi.org/10.1016/j.physa.2020.125170 VL - 560 IS - December PB - Elsevier ER - TY - JOUR A1 - Glavan, Gašper A1 - Belyaeva, Inna A. A1 - Ruwisch, Kevin A1 - Wollschlaeger, Joachim A1 - Shamonin (Chamonine), Mikhail T1 - Magnetoelectric Response of Laminated Cantilevers Comprising a Magnetoactive Elastomer and a Piezoelectric Polymer, in Pulsed Uniform Magnetic Fields JF - Sensors N2 - The voltage response to pulsed uniform magnetic fields and the accompanying bending deformations of laminated cantilever structures are investigated experimentally in detail. The structures comprise a magnetoactive elastomer (MAE) slab and a commercially available piezoelectric polymer multilayer. The magnetic field is applied vertically and the laminated structures are customarily fixed in the horizontal plane or, alternatively, slightly tilted upwards or downwards. Six different MAE compositions incorporating three concentrations of carbonyl iron particles (70 wt%, 75 wt% and 80 wt%) and two elastomer matrices of different stiffness are used. The dependences of the generated voltage and the cantilever's deflection on the composition of the MAE layer and its thickness are obtained. The appearance of the voltage between the electrodes of a piezoelectric material upon application of a magnetic field is considered as a manifestation of the direct magnetoelectric (ME) effect in a composite laminated structure. The ME voltage response increases with the increasing total quantity of the soft-magnetic filler in the MAE layer. The relationship between the generated voltage and the cantilever's deflection is established. The highest observed peak voltage around 5.5 V is about 8.5-fold higher than previously reported values. The quasi-static ME voltage coefficient for this type of ME heterostructures is about 50 V/A in the magnetic field of approximate to 100 kA/m, obtained for the first time. The results could be useful for the development of magnetic field sensors and energy harvesting devices relying on these novel polymer composites. KW - cantilever KW - composites KW - DEMAGNETIZING FACTORS KW - direct magnetoelectric effect KW - laminated structure KW - magnetic field sensor KW - magnetoactive elastomer KW - piezoelectric polymer Y1 - 2021 U6 - https://doi.org/10.3390/s21196390 N1 - Corresponding authors: Gašper Glavan, Mikhail Shamonin VL - 21 IS - 19 SP - 1 EP - 19 PB - MDPI CY - Basel ER - TY - JOUR A1 - Savelev, Dmitrii V. A1 - Belyaeva, Inna A. A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. A1 - Romeis, Dirk A1 - Kettl, Wolfgang A1 - Kramarenko, Elena Yu A1 - Saphiannikova, Marina A1 - Stepanov, Gennady V. A1 - Shamonin (Chamonine), Mikhail T1 - Giant extensional strain of magnetoactive elastomeric cylinders in uniform magnetic fields JF - Materials N2 - Elongations of magnetoactive elastomers (MAEs) under ascending–descending uniform magnetic fields were studied experimentally using a laboratory apparatus specifically designed to measure large extensional strains (up to 20%) in compliant MAEs. In the literature, such a phenomenon is usually denoted as giant magnetostriction. The synthesized cylindrical MAE samples were based on polydimethylsiloxane matrices filled with micrometer-sized particles of carbonyl iron. The impact of both the macroscopic shape factor of the samples and their magneto-mechanical characteristics were evaluated. For this purpose, the aspect ratio of the MAE cylindrical samples, the concentration of magnetic particles in MAEs and the effective shear modulus were systematically varied. It was shown that the magnetically induced elongation of MAE cylinders in the maximum magnetic field of about 400 kA/m, applied along the cylinder axis, grew with the increasing aspect ratio. The effect of the sample composition is discussed in terms of magnetic filler rearrangements in magnetic fields and the observed experimental tendencies are rationalized by simple theoretical estimates. The obtained results can be used for the design of new smart materials with magnetic-field-controlled deformation properties, e.g., for soft robotics. KW - magnetostriction KW - magnetoactive elastomer KW - extensional strain KW - hysteresis KW - magnetomechanical effect KW - magnetodeformation Y1 - 2020 U6 - https://doi.org/10.3390/ma13153297 SN - 1996-1944 N1 - Corresponding author: Mikhail Shamonin VL - 13 IS - 15 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Savelev, Dmitrii V. A1 - Fetisov, Leonid Y. A1 - Chashin, Dmitri V. A1 - Fetisov, Yuri K. A1 - Khon, Anastasia A1 - Shamonin (Chamonine), Mikhail T1 - Effects of ferromagnetic-material thickness on magnetoelectric voltage transformation in a multiferroic heterostructure JF - Smart Materials and Structures N2 - A magnetoelectric (ME) voltage transformer is fabricated on the basis of a ferromagnetic (FM)-piezoelectric (PE) heterostructure comprising two equally thick laminated layers of an amorphous FM alloy and a piezoceramic lead zirconate-titanate layer sandwiched between them. The structure, placed inside an excitation coil, is electrically poled and magnetized in the direction of the long axis. The primary voltage is applied to the coil and the secondary voltage is measured between the electrodes of the PE material. It is shown for the first time that the change in the total thickness of magnetic layers significantly influences the transformer ' s characteristics. At the largest total thickness of FM layers of 138 mu m, the open-circuit voltage transformation ratio K has a maximum value of about 20, and the power transfer efficiency eta at a matched resistive load of about 20 k omega reaches 45%. The variation of the control magnetic field in the range of 0-21.6 kA m(-1) makes it possible to change the voltage transformation ratio K from zero to the maximum value. A simple model allows one to calculate the dependence of the characteristics of the ME transformer on the frequency of the primary voltage, thickness of the FM layers, control magnetic field, and the load. KW - magnetoelectric effect KW - magnetostriction KW - multiferroic heterostructure KW - piezoelectric effect KW - voltage transformer Y1 - 2021 U6 - https://doi.org/10.1088/1361-665X/abf6c0 VL - 30 IS - 6 PB - IOP PUBLISHING ER -