TY - CHAP A1 - Ezer, Timur A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Staufer, Susanne A1 - Mottok, Jürgen T1 - EYE TRACKING AS TECHNOLOGY IN EDUCATION: FURTHER INVESTIGATION OF DATA QUALITY AND IMPROVEMENTS T2 - INTED2024 Proceedings: 18th International Technology, Education and Development Conference, Valencia, Spain. 4-6 March, 2024 N2 - Eye tracking serves as a powerful tool across a variety of empirical research areas: From usability research over cognitive research to educational research and applications in classrooms. However, data noise in eye tracking data poses a challenge to researchers and educators, as it leads to gaze positions being measured imprecisely under unfavorable conditions. In our previous study, we systematically investigated factors that influence data quality and are easily controllable in a classroom or laboratory environment, such as illumination, sampling frequency, and head orientation. However, no recommendations regarding the light source and light orientation could be provided, as these influences could not be analyzed in sufficient detail. Yet, a further examination of these factors, eliminating human influences by using an artificial head, revealed significant differences between individual settings. Hence, in this empirical study of eye tracking as an educational technology, we delve deeper into examining the impact of both light source and light orientation on data quality. This is investigated with an artificial head together with the Tobii Pro Spectrum eye tracking device. To measure data quality, we use the metrics precision and standard deviation as indicators of data noise. The obtained results derive practical advice for educators and researchers, such as not to illuminate the subject from the rear, in order to gather useful data for research and future classroom applications. Thereby, this study serves as a complement to our previous research, answering open questions regarding best practices for researchers and educators when using eye trackers. It aims to provide valuable insights into producing data of the highest quality possible when using eye trackers, both in laboratory settings and in future classrooms applications. KW - Eye tracking KW - data quality KW - best practices KW - lighting conditions KW - standard deviation KW - precision Y1 - 2024 SN - 978-84-09-59215-9 U6 - https://doi.org/10.21125/inted.2024.0802 SN - 2340-1079 SP - 2955 EP - 2961 PB - IATED Academy ER - TY - CHAP A1 - Ezer, Timur A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Staufer, Susanne A1 - Mottok, Jürgen T1 - EYE TRACKING METRICS FOR DISTINGUISHING GLOBAL AND FOCAL GAZE PATTERNS: A SYSTEMATIC LITERATURE REVIEW T2 - INTED2024 Proceedings: 18th International Technology, Education and Development Conference, Valencia, Spain. 4-6 March, 2024 N2 - Global and focal eye tracking gaze patterns are distinguished in a variety of domains, such as radiology research, empirical software engineering, behavioral psychology, and cartography research. A global gaze pattern is present if a participant in an eye tracking study gains an overview of the stimulus, whereas a focal pattern emerges during a more detailed evaluation of a specific part of the stimulus. With this higher-level measure of global and focal gaze patterns, cognitive effort, expertise levels, and even neurological characteristics - such as autism - can be quantified. Furthermore, with this measure, cognitive efforts of students in certain tasks can be investigated and clues for targeted support can be provided. These properties in particular make this eye tracking measure valuable for the education domain. In the field of eye tracking research, many researchers have established distinct criteria for differentiating global and focal gaze patterns. Moreover, it is rarely quantitatively measured which of these patterns is present, but rather determined based on qualitative considerations. However, some studies explicitly use quantitative metrics like saccade-length or fixation-duration to distinguish between global and focal gaze patterns. This is the focus of the present systematic literature review: It searches for and compiles the eye tracking metrics used in the literature to distinguish global from focal gaze patterns in a quantitative way. In doing so, this study fills the yawning gap in quantitative metrics for determining global and focal gaze patterns. In the long run, this can be used to answer questions about cognitive load and problems in processing tasks during eye tracking studies and to provide further insights into the cognitive processes of students. The present paper first discusses definitions of global and focal gaze patterns and presents examples in which this metric has already been applied. Then, the research questions together with search strings and search engines used for the systematic literature review are described. Finally, the results are summarized, presenting a compilation of and connections between quantitative metrics utilized in the literature to distinguish between global and focal viewing patterns. KW - Eye tracking KW - cognitive load KW - expertise KW - global KW - focal KW - ambient KW - local KW - metrics Y1 - 2024 SN - 978-84-09-59215-9 U6 - https://doi.org/10.21125/inted.2024.0814 SN - 2340-1079 SP - 3005 EP - 3014 PB - IATED Academy ER - TY - CHAP A1 - Staufer, Susanne A1 - Bugert, Flemming A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Ezer, Timur A1 - Nadimpalli, Vamsi Krishna A1 - Bittner, Dominik A1 - Röhrl, Simon A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - Tyche algorithm: Markov models for generating learning paths in learning management systems T2 - INTED2024 Proceedings: 18th International Technology, Education and Development Conference, Valencia, Spain. 4-6 March, 2024 N2 - In the intricate tapestry of the cosmos, where celestial threads weave stories of destiny, an enigmatic deity stands at the intersection of chance and fate — Tyche, the goddess of fortune. In science and probability, coincidence plays a distinctive role in Bayesian Networks (BNs) and Markov Models (MMs). This paper introduces the Tyche algorithm named after the goddess of fortune. The Tyche algorithm is a Markov model designed to generate learning paths in Learning Management Systems (LMSs). A learning path is a type of individualization that personalises the order of learning elements within an LMS course. Learning elements are fundamental components within an LMS course, depicting the learning content in diverse ways. In our case, the learning path tailoring is based on the learner’s learning style according to Felder-Silverman Learning Style Model (FSLSM) – an indicator for the ideal pathway and learning element for the learner’s optimum learning. The Tyche algorithm offers the advantage to provide students the most suitable learning path. Tyche is a MM structure with various matrices containing transition probabilities depending on the learning style. Nine categories of learning elements defined in a previous survey form the basis of the node structure of the MM. For a generic approach, a survey was designed to obtain the transition probabilities depending on the individual learning style. The survey with more than 100 German students participated is processed with the tool LimeSurvey. Students are asked about their learning style using the Index of Learning Styles (ILS) questionnaire according to Felder-Silverman and about the percentage probabilities of learning elements to get their individual sequence as learning path. The percentages are queried in two different ways. Firstly, the students were asked to provide a sequence of learning elements within each position of the sequence filled with probabilities for all learning elements. Secondly, a learning element is given and the students are asked to indicate which learning element they would work on next. The first way of asking for the probabilities is used to find the start node in the MM, whereas the second approach forms the probability matrices between the nodes within the MM. As result of the survey, the Tyche algorithm presents generic transition probabilities. It improves the learning process of individuals only by asking for their learning style: it generates individual learning paths through the learning elements within an LMS based on the MM explained above by solely getting the answers of the ILS questionnaire as input. In the future, other questionnaires such as BFI-10 for personality traits or LIST-K for learning strategies may offer a more comprehensive input. However, the next step is to evaluate Tyche with about 25 students in a software engineering lecture. This is planned for the year 2024. KW - Markov model KW - learning style KW - learning elements KW - learning management system KW - higher education area Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-71148 SN - 978-84-09-59215-9 SN - 2340-1079 SP - 4195 EP - 4205 PB - IATED Academy ER - TY - JOUR A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Wolff, Christian A1 - Mottok, Jürgen T1 - On Eye Tracking in Software Engineering JF - SN Computer Science N2 - Eye tracking is becoming more and more important as a research method within the field of software engineering (SE). Existing meta-analyses focus on the design or conduct of SE eye tracking studies rather than the analysis phase. This article attempts to fill this gap; it presents a systematic literature review of eye tracking studies in the field of SE—focusing mainly on the data analysis methods used. From the IEEE Xplore and ACM digital libraries we gather 125 papers up to the first quarter of 2024. Detailed evaluation provides information on the number of papers that use specific methods of analysis (i.e., descriptive or inferential statistics, and gaze visualization) or settings (e.g., sample size, technical setup, and selected aspects of research design). With the data obtained we can infer the popularity of specific analysis methods in the field. Those results enable efficient work on data analysis tools or education of aspiring researchers and can serve as basis for standardization or guidelines within the community—providing for methods to include as well as current inconsistencies. KW - Eye tracking KW - Software engineering KW - Empirical KW - Systematic literature review Y1 - 2024 U6 - https://doi.org/10.1007/s42979-024-03045-3 SN - 2661-8907 N1 - Zugehöriges Datenset: doi:10.5281/zenodo.11279180 VL - 5 IS - 6 PB - Springer CY - Singapore ER - TY - JOUR 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 JF - Energies N2 - The fluctuating nature of renewable energies results in the need for sustainable storage technologies to defossilize the energy system without other negative consequences for humans and the environment. In this study, a pilot-scale trickle-bed reactor for biological methanation and various scale-up scenarios for 2024 and 2050 were investigated using life cycle assessment. A best- and worst-case scenario for technology development until 2050 was evolved using cross-consistency analysis and a 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 electrolysis operation has an especially large impact on total emissions. The final Monte Carlo simulation shows that the technology is likely to achieve a low global warming potential with a median of 104.0 kg CO2-eq/MWh CH4 and thus can contribute to decarbonization. KW - Ökobilanzierung KW - Power-to-Gas KW - Elektrolyse KW - Methanisierung KW - erneuerbare Energien Y1 - 2024 U6 - https://doi.org/https://doi.org/10.3390/en17092206 SN - 1996-1073 VL - 17 IS - 9 PB - MDPI AG CY - Basel ER - TY - JOUR A1 - Pandey, Mahesh A1 - Viljoen, Celeste A1 - Way, Andrew A1 - Katharina Fischer, Katharina A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Steenbergen, Raphaël D.J.M. A1 - Lind, Niels A1 - Frangopol, Dan M. A1 - Yang, David Y. A1 - Retief, Johan Verster A1 - André, João A1 - Nathwani, Jatin A1 - Lenner, Roman T1 - Life safety in the Reliability-Based design and assessment of structures JF - Structural Safety N2 - We review the developments in life safety and the incorporation thereof in the design and assessment of structures over the last 50 years. Various measures of life safety are presented that have been developed according to the marginal life saving cost principle based on individual, societal and economic considerations. Target probabilities of failure, or target reliabilities, are central to modern structural design and assessment. These are derived either through back-calibration to existing practice or through life cycle cost minimisation, both of which yield comparable safety levels, and are underpinned by lower bounds from life safety. Life cycle cost minimisation is reviewed here, which considers all direct and indirect costs of failure including loss of life and limb, as well as the costs and efficiency of increasing reliability. We discuss the incorporation of life safety into reliability-based design and assessment through the concept of the Life Quality Index, which uses key societal indicators, namely, the GDP and life expectancy, and health economics as a basis for specifying minimum reliabilities for both new and existing structures. The current state of advancement of reliability- and risk-informed design, and recommendations for future developments in life safety are considered. KW - Life safety KW - Structural assessment KW - Standardization KW - Reliability-based design KW - Risk-informed design Y1 - 2024 U6 - https://doi.org/10.1016/j.strusafe.2024.102453 PB - Elsevier ER - TY - CHAP A1 - Staufer, Susanne A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Bittner, Dominik A1 - Nadimpalli, Vamsi Krishna A1 - Bugert, Flemming A1 - Ezer, Timur A1 - Röhrl, Simon A1 - Mottok, Jürgen T1 - Learning elements in LMS - a survey among students T2 - INTED2024 Proceedings: 18th International Technology, Education and Development Conference, Valencia, Spain. 4-6 March, 2024 N2 - In higher education, improving learning and learning success are goals of general improvement. Lecturers teaches content and students acquire that content in an efficient way. To structure content, learning element categories are evaluated from the student's point of view in higher education area. The aim is to validate given definitions of ten learning element categories within a Learning Management System (LMS). This paper evaluates a categorization of learning elements for organizing learning content in online education within LMSs. Therefore, ten categories of learning elements and corresponding definitions were defined in a previous work as base for this paper. The learning elements to examine are manuscript, exercise, quiz, brief overview, learning goal, summary, collaboration tool, auditory additional material, textual additional material, and visual additional material. To validate the definitions and to get improvements to each learning element a survey is processed. Beside the demographic data questions, the survey consists of two questions to the acceptance of the definitions and asks for improvements. 148 students between the ages 19 and 35 participate in the survey in summer term 2023. The education level of the participants ranges from undergraduates to Ph.D. students. The results of this paper are that more than 80% accept the given definitions. Some definitions of the learning elements are changed, but the changes are restricted to additions of maximal four words. This categorization of learning elements could lead to improvements in learning by giving the content more structure. With the structure students get the possibility to learn with preferred learning elements which could lead to more success in learning and to a decreasing dropout rate in universities. In the future, the learning elements allow to classify content within LMSs with the goal of generating individual learning paths. Furthermore, our project will integrate these learning elements, use them to generate learning paths, and could set a new standard in the way of personalized learning. KW - Learning elements KW - learning management system KW - learning objects KW - questionnaire KW - higher education area KW - content organization Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-71135 SN - 978-84-09-59215-9 SN - 2340-1079 SP - 4224 EP - 4231 PB - IATED ER - TY - GEN A1 - Marterer, Verena T1 - Simulation of the Electromagnetic Properties of Knitted Structures N2 - 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. KW - Textile Antennas KW - Wearables KW - Periodic Structure Y1 - 2024 ER - TY - JOUR A1 - Maier, Robert A1 - Schlattl, Andreas A1 - Guess, Thomas A1 - Mottok, Jürgen T1 - CausalOps - Towards an industrial lifecycle for causal probabilistic graphical models JF - Information and Software Technology N2 - Context: Causal probabilistic graph-based models have gained widespread utility, enabling the modeling of cause-and-effect relationships across diverse domains. With their rising adoption in new areas, such as safety analysis of complex systems, software engineering, and machine learning, the need for an integrated lifecycle framework akin to DevOps and MLOps has emerged. Currently, such a reference for organizations interested in employing causal engineering is missing. This lack of guidance hinders the incorporation and maturation of causal methods in the context of real-life applications. Objective: This work contextualizes causal model usage across different stages and stakeholders and outlines a holistic view of creating and maintaining them within the process landscape of an organization. Method: A novel lifecycle framework for causal model development and application called CausalOps is proposed. By defining key entities, dependencies, and intermediate artifacts generated during causal engineering, a consistent vocabulary and workflow model to guide organizations in adopting causal methods are established. Results: Based on the early adoption of the discussed methodology to a real-life problem within the automotive domain, an experience report underlining the practicability and challenges of the proposed approach is discussed. Conclusion: It is concluded that besides current technical advancements in various aspects of causal engineering, an overarching lifecycle framework that integrates these methods into organizational practices is missing. Although diverse skills from adjacent disciplines are widely available, guidance on how to transfer these assets into causality-driven practices still need to be addressed in the published literature. CausalOps’ aim is to set a baseline for the adoption of causal methods in practical applications within interested organizations and the causality community. KW - Causal engineering KW - Model lifecycle KW - MLOps KW - Causal graphical models Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-73350 SN - 0950-5849 N1 - Corresponding author der OTH Regensburg: Robert Maier PB - Elsevier ER - TY - JOUR A1 - Kral, Christian A1 - Haumer, Anton A1 - Kapeller, Hansjörg A1 - Pirker, Franz T1 - Design and Thermal Simulation of Induction Machines for Traction in Electric and Hybrid Electric Vehicles JF - World Electric Vehicle Journal N2 - An electric traction machine for an electric or a hybrid electric vehicle is usually designed for a specific operating point or cycle. For such an operating point or cycle, the masses and the cooling circuit of the electric machine determine the time dependent temperature distribution within the machine. For a specific load cycle, the thermal simulation of the machine can reveal possible mass and size reductions for a given insulation class of the machine. In addition, such simulations allow the comparison of various cooling concepts. In the machine design process, the first step is a conventional electromagnetic machine design. From the geometric data of this design and the material properties, the parameters of a thermal equivalent circuit can be derived. The differential and algebraic equations of the thermal equivalent circuit are solved by a simulation tool to predict the temperatures of the critical parts in the electric machine. A thermal equivalent circuit is accurate enough to predict the thermal behavior of the critical parts in the electric machine, and yet not too complex, to obtain simulation results with moderate numerical effort. This enables an iterative design process to optimize the drive. KW - Induction Motor KW - Electric Drive KW - Modeling KW - Simulation KW - Thermal Management Y1 - 2007 U6 - https://doi.org/10.3390/wevj1010190 SN - 2032-6653 VL - 1 IS - 1 SP - 190 EP - 196 PB - MDPI ER - TY - JOUR A1 - Loo, Xuyan A1 - Nagaraju, Bhavana A1 - Pathivada, Sai A1 - Bartsch, Alexander A1 - Schratzenstaller, Thomas A1 - Sattler, Robert A1 - Monkman, Gareth J. T1 - Electrical properties of bisphenol-A-free magnetoactive borosilicate polymers JF - AIP Advances N2 - The recent REACH regulations require the elimination of bisphenol-A and titanium dioxide from commercially available boron-based polymers. This has led to changes in some of the mechanical characteristics, which strongly influence the properties of magnetoactive borosilicate polymers. This work delivers results on the electrical properties and discusses some implications for future research using bisphenol-A and titanium-dioxide-free substitutes. KW - Electrical components KW - Electrical properties and parameters KW - Dielectric properties KW - Electrical resistivity KW - Magnetic materials KW - Viscoelasticity KW - Polymers KW - Non Newtonian fluids KW - Magnetic fluids Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-72936 SN - 2158-3226 N1 - Corresponding author der OTH Regensburg: Gareth J. Monkman VL - 14 IS - 5 PB - AIP Publishing ER - TY - CHAP A1 - Haumer, Anton T1 - Modeling and Control Design of an Educational Magnetic Levitation System T2 - Proceedings of the 15th International Modelica Conference 2023, Aachen, October 9-11 N2 - A magnetic levitation system is a perfect educational example of a nonlinear unstable system. Only with suitable control, a small permanent magnet can be held floating stable below a coil. After modeling and simulation of the system, control of the system can be developed. At the end, the control algorithm can be coded on a microcontroller, connected to a pilot plant. KW - mechatronics KW - magnetic levitation KW - time-discrete control KW - functional mockup interface Y1 - 2023 U6 - https://doi.org/10.3384/ecp204763 SN - 1650-3686 PB - Linköping University Electronic Press ER - TY - INPR A1 - Schumm, Leon A1 - Abdel-Khalek, Hazem A1 - Brown, Tom A1 - Ueckerdt, Falko A1 - Sterner, Michael A1 - Fioriti, Davide A1 - Parzen, Max T1 - The impact of temporal hydrogen regulation on hydrogen exporters and their domestic energy transition N2 - As global demand for green hydrogen rises, potential hydrogen exporters move into the spotlight. However, the large-scale installation of on-grid hydrogen electrolysis for export can have profound impacts on domestic energy prices and energy-related emissions. Our investigation explores the interplay of hydrogen exports, domestic energy transition and temporal hydrogen regulation, employing a sector-coupled energy model in Morocco. We find substantial co-benets of domestic climate change mitigation and hydrogen exports, whereby exports can reduce domestic electricity prices while mitigation reduces hydrogen export prices. However, increasing hydrogen exports quickly in a system that is still dominated by fossil fuels can substantially raise domestic electricity prices, if green hydrogen production is not regulated. Surprisingly, temporal matching of hydrogen production lowers domestic electricity cost by up to 31% while the effect on exporters is minimal. This policy instrument can steer the welfare (re-)distribution between hydrogen exporting firms, hydrogen importers, and domestic electricity consumers and hereby increases acceptance among actors. KW - Energy Transition KW - Hydrogen regulation KW - Hydrogen export KW - Climate-neutral KW - Domestic prices KW - Hydrogen prices KW - Power-to-X Y1 - 2024 U6 - https://doi.org/10.21203/rs.3.rs-4285425/v1 N1 - Der Aufsatz wurde peer-reviewed veröffentlicht und ist ebenfalls in diesem Repositorium verzeichnet unter: https://opus4.kobv.de/opus4-oth-regensburg/8485 PB - Research Square Platform LLC ER - TY - JOUR A1 - Kriegl, Raphael A1 - Jezeršek, Matija A1 - Kravanja, Gaia A1 - Hribar, Luka A1 - Mukhi, Soham A1 - Kokot, Gašper A1 - Drevenšek‐Olenik, Irena A1 - Shamonin (Chamonine), Mikhail T1 - Tunable rebound of millimeter-sized rigid balls by magnetic actuation of elastomer-based surface microstructures JF - Smart Materials and Structures N2 - A novel method for controlling the rebound behavior of small balls made of Al2O3 with a radius of 2.381 mm is presented. It uses different types of micro-structured surfaces of soft magnetoactive elastomers. These surfaces were fabricated via laser micromachining and include fully ablated surfaces as well as micrometer-sized lamellas with a fixed width of 90 µm, height of 250 µm and three different gap sizes (15, 60 and 105 µm). The lamellas can change their orientation from edge-on to face-on configuration according to the direction of the external magnetic field from a permanent magnet. The orientation of the external magnetic field significantly influences the rebound behavior of the balls, from a coefficient of restitution e of to < 0.1. The highest relative change in the coefficient of restitution between zero field and face-on configuration of is observed for lamellas with a gap of 60 µm. Other characteristics of the ball rebound such as the penetration depth into an Magnetoactive elastomer and the maximum deceleration are investigated as well. The proposed method does not require a constant power supply due to the use of permanent magnets. It may find novel applications in the field of impact engineering. Y1 - 2024 U6 - https://doi.org/10.1088/1361-665X/ad41a9 N1 - Zugehöriges Datenset: https://doi.org/10.5281/zenodo.10419411 VL - 33 IS - 6 PB - IOP Publishing ER - TY - JOUR A1 - Marterer, Verena A1 - Radouchová, Michaela A1 - Soukup, Radek A1 - Hipp, Susanne A1 - Blecha, Tomáš T1 - Wearable textile antennas: investigation on material variants, fabrication methods, design and application JF - Fashion and Textiles N2 - 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. KW - Wearable communication KW - Textile antenna KW - Patch antenna KW - Design requirements KW - Smart textiles KW - E-textiles Y1 - 2024 U6 - https://doi.org/10.1186/s40691-023-00369-1 VL - 11 PB - Springer Open ER - TY - CHAP A1 - Kraus, Hermann A1 - Brückl, Oliver T1 - Automated use of wired measures in grid planning for solving current and voltage band problems T2 - Power and Energy Student Summit (PESS) 2019, Magdeburg N2 - This work deals with the use of cable exchange and parallel cabling as network expansion measures in the context of an automated grid planning for the elimination of current and voltage band problems in a distribution network. Inter alia, reference is made to a higher-level program, which is being developed in the EU project "CrossEnergy", and the procedures for remedying the limit value violations are presented. KW - Netzplanung KW - Automatisierung KW - Netzverstärkung KW - Leitungsmaßnahme Y1 - 2019 SN - 978-3-944722-84-9 U6 - https://doi.org/10.24352/UB.OVGU-2019-086 VL - 77 SP - 207 EP - 211 PB - Otto-von-Guericke-Universität, Institut für Elektrische Energiesysteme CY - Magdeburg ER - TY - JOUR A1 - Glavan, Gašper A1 - Belyaeva, Inna A. A1 - Shamonin (Chamonine), Mikhail T1 - Transient Response of Macroscopic Deformation of Magnetoactive Elastomeric Cylinders in Uniform Magnetic Fields JF - Polymers N2 - Significant deformations of bodies made from compliant magnetoactive elastomers (MAE) in magnetic fields make these materials promising for applications in magnetically controlled actuators for soft robotics. Reported experimental research in this context was devoted to the behaviour in the quasi-static magnetic field, but the transient dynamics are of great practical importance. This paper presents an experimental study of the transient response of apparent longitudinal and transverse strains of a family of isotropic and anisotropic MAE cylinders with six different aspect ratios in time-varying uniform magnetic fields. The time dependence of the magnetic field has a trapezoidal form, where the rate of both legs is varied between 52 and 757 kA/(s·m) and the maximum magnetic field takes three values between 153 and 505 kA/m. It is proposed to introduce four characteristic times: two for the delay of the transient response during increasing and decreasing magnetic field, as well as two for rise and fall times. To facilitate the comparison between different magnetic field rates, these characteristic times are further normalized on the rise time of the magnetic field ramp. The dependence of the normalized characteristic times on the aspect ratio, the magnetic field slew rate, maximum magnetic field values, initial internal structure (isotropic versus anisotropic specimens) and weight fraction of the soft-magnetic filler are obtained and discussed in detail. The normalized magnetostrictive hysteresis loop is introduced, and used to explain why the normalized delay times vary with changing experimental parameters. KW - magnetoactive elastomer KW - magnetorheological elastomer KW - macroscopic deformation KW - magnetostriction KW - time-varying magnetic field Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-71067 SN - 2073-4360 N1 - Corresponding author der OTH Regensburg: Gašper Glavan Zugehöriges Datenset: doi:10.5281/zenodo.10679499 VL - 16 IS - 5, Special Issue Magnetic Polymer Composites: Design and Application II PB - MDPI CY - Basel, Schweiz ER - TY - CHAP A1 - Fuhrmann, Thomas A1 - Niemetz, Michael T1 - Analysis and Improvement of Engineering Exams Toward Competence Orientation by Using an AI Chatbot T2 - Towards a Hybrid, Flexible and Socially Engaged Higher Education: Proceedings of the 26th International Conference on Interactive Collaborative Learning (ICL2023), Volume 1 N2 - ChatGPT is currently one of the most advanced general chatbots. This development leads to diverse challenges in higher education, like new forms of teaching and learning, additional exam methods, new possibilities for plagiarism, and many more topics. On the other side with the development of advanced AI tools, pure knowledge will be less and less important, and demands from industry will change toward graduates with higher competencies. Education has therefore to be changed from knowledge-centered toward competence centered. The goal of this article is to use ChatGPT for analyzing and improving the competence orientation of exams in engineering education. The authors use ChatGPT to analyze exams from different engineering subjects to evaluate the performance of this chatbot and draw conclusions about the competence orientation of the tested exams. The obtained information is used to develop ideas for increasing the competence orientation of exams. From this analysis, it is visible that ChatGPT gives good performance mainly where knowledge is tested. It has, however, much more problems with transfer questions or tasks where students need creativity or complex insights for finding new solutions. Based on this result, exams and also lectures can be optimized toward competence orientation. KW - Engineering education KW - Competence orientation KW - Exam analysis KW - AI chatbot KW - ChatGPT Y1 - 2024 SN - 9783031519789 U6 - https://doi.org/10.1007/978-3-031-51979-6_42 SN - 2367-3370 SP - 403 EP - 411 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Johnson, Ebin M. A1 - Anwer, Shakil A1 - Xu, Yongchao A1 - Fuhrmann, Thomas A1 - Mandl, Roland T1 - Contactless Low-Cost Position Sensor using a D-Shaped Polymer Optical Fiber JF - IEEE Sensors Journal N2 - This article describes a contactless fiber-optic position sensor. It comprises a Polymer Optical Fiber that is grinded to form a D-shaped cross-section with an exposed fiber core. This sensor has two photodiodes at both fiber ends to measure the emitted light intensity. Light is coupled using a red LED at the side face into the exposed core of the fiber at a defined position. The position of the LED at the length of the fiber is measured by calculating the optical power quotient measured by both photodiodes. To test this sensor, Polymer Optical Fibers with different side surface roughness are produced and qualified. Measurements show that the optical power quotient is reproducible and nearly linear over the length of the fiber. It is also seen that the fiber attenuation increases when grinding the fiber side-face with rougher sandpaper. Position measurements show an absolute position error of this sensor in the range of a few millimeters. Microscope images show surface defects along the polished side face of the fiber that are expected to lead to a nonuniform attenuation along the fiber and cause the position errors. Overall, it is proven that this sensor principle works as a contactless low-cost position sensor for short distances with an absolute position standard deviation error lower than 1 mm. KW - Optical fibers KW - Optical fiber sensors KW - Sensors KW - Photodiodes KW - Optical surface waves KW - Surface roughness KW - Rough surfaces KW - Fiber-optic sensor KW - Position measurement KW - Polymer Optical Fiber Y1 - 2024 U6 - https://doi.org/10.1109/JSEN.2023.3348127 PB - IEEE ER - TY - CHAP A1 - Franke, Ariane ED - Uhl, Christian ED - Walter, Michael ED - Stiehl, Annika T1 - Electricity load forecasting for industrial microgrid and load management T2 - Applied Research Conference 2022 Conference Proceedings: 4th July 2022, University of Applied Sciences Ansbach (Onsite Conference) N2 - As more energy systems from renewable sources and the electricity market becomes more volatile, new solutions to ensure the security of supply are tested. Microgrids offer a possibility to prevent construction downtime. In order to use the energy sources and storage facilities of the microgrid effectively, load forecasting algorithms are essential. Thus, in this study a short term load forecasting model for a construction company is designed, that will be used for managing a microgrid as well as the general load consumption. This paper proposes the use of the XGBoost algorithm for the 36-hour forecast including predictors based on past measurements as well as information extracted from the timestamp. Moreover, it is shown that including load profiles attained by conventional methods has the potential to improve the accuracy of the model. KW - load forecast KW - XGBoost KW - load profile Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-68231 SP - 405 EP - 409 PB - Hochschule Ansbach CY - Ansbach ER - TY - CHAP A1 - Schweiberer, Philipp A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Control strategy for industrial reactive power sources depending on a specified reactive power setpoint value T2 - ETG Kongress 2023: Die Energiewende beschleunigen, 25.-26. Mai 2023, Kassel, Germany N2 - 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. Y1 - 2023 UR - https://ieeexplore.ieee.org/document/10173014/authors#authors SN - 978-3-8007-6108-1 SP - 553 EP - 558 PB - VDE VERLAG CY - Berlin ER - TY - GEN A1 - Kriegl, Raphael A1 - Kravanja, Gaia A1 - Hribar, Luka A1 - Jezeršek, Matija A1 - Drevenšek‐Olenik, Irena A1 - Shamonin (Chamonine), Mikhail T1 - Characterization of Wetting Properties of Magnetoactive Elastomer Surfaces T2 - Proceedings of the ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS) - 2023, September 11–13, 2023 Austin, Texas, USA N2 - Commercially available contact angle (CA) measuring devices usually do not allow for the application of magnetic fields to the sample under test. A setup for measuring the CA of liquids on magnetosensitive surfaces has been developed specifically for investigating the surfaces of magnetoactive elastomers (MAEs). The addition of a programmable linear stage, which moves a permanent magnet, allows for fine control of the magnetic field applied to the MAE without the need for large and power-consuming electromagnets. Paired with a custom control and evaluation software, this measurement setup operates semiautomatically, limiting operator error and increasing precision, speed, as well as repeatability of static and dynamic CA measurements for different magnetoactive materials. The software is equipped with robust droplet fitting algorithms to avoid experimental challenges arising with soft magnetoactive materials, such as the curling of sample edges or diffuse non-reflective surfaces. Several application examples on MAE surfaces, both processed and unprocessed, are presented. KW - magnetoactive elastomers KW - image processing KW - droplet contour fitting KW - contact angle Y1 - 2023 SN - 978-0-7918-8752-3 U6 - https://doi.org/10.1115/SMASIS2023-110998 N1 - Corresponding author: Raphael Kriegl PB - The American Society of Mechanical Engineers CY - New York, USA 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 - CHAP A1 - Staufer, Susanne A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Bittner, Dominik A1 - Nadimpalli, Vamsi Krishna A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - Learning elements in online learning management systems T2 - Proceedings of the 16th annual International Conference of Education, Research and Innovation (ICERI 2023), Seville, Spain, 11/13/2023 - 11/14/2023 Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-67725 SP - 3121 EP - 3130 PB - IATED 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 - 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 - CHAP A1 - Ezer, Timur A1 - Greiner, Matthias A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - Eye tracking al technology in education; data quality analysis and improvements T2 - Proceedings of the 16th annual International Conference of Education, Research and Innovation (ICERI 2023), Seville, Spain, 11/13/2023 - 11/14/2023 N2 - Eye tracking has proven to be a powerful tool in a variety of empirical research areas; hence, it is steadily gaining attention. Driven by the expanding frontiers of Artificial Intelligence and its potential for data analysis, eye tracking technology offers promising applications in diverse fields, from usability research to cognitive research. The education sector in particular can benefit from the increased use of eye tracking technology - both indirectly, for example by studying the differences in gaze patterns between experts and novices to identify promising strategies, and directly by using the technology itself to teach in future classrooms. As with any empirical method, the results depend directly on the quality of the data collected. That raises the question of which parameters educators or researchers can influence to maximize the data quality of an eye tracker. This is the starting point of the present work: In an empirical study of eye tracking as an (educational) technology, we systematically examine factors that influence the data quality, such as illumination, sampling frequency, and head orientation - parameters that can be varied without much additional effort in everyday classroom or research use - using two human subjects, an artificial face, and the Tobii Pro Spectrum. We rely on metrics derived from the raw gaze data, such as accuracy or precision, to measure data quality. The obtained results derive practical advice for educators and researchers, such as using the lowest sampling frequency appropriate for a certain purpose. Thereby, this research fills a gap in the current understanding of eye tracker performance and, by offering best practices, enables researchers or teachers to produce data of the highest quality possible and therefore best results when using eye trackers in laboratories or future classrooms. Y1 - 2023 U6 - https://doi.org/10.21125/iceri.2023.1127 SP - 4500 EP - 4509 PB - IATED ER - TY - CHAP A1 - Bittner, Dominik A1 - Ezer, Timur A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - Unveiling the secrets of learning styles: decoding eye movements via machine learning T2 - Proceedings of the 16th annual International Conference of Education, Research and Innovation (ICERI 2023), Seville, Spain, 11/13/2023 - 11/14/2023 N2 - Universities are faced with a rising number of dropouts in recent years. This is largely due to students' limited capability of finding individual learning paths through various course materials. However, a possible solution to this problem is the introduction of adaptive learning management systems, which recommend tailored learning paths to students – based on their individual learning styles. For the classification of learning styles, the most commonly used methods are questionnaires and learning analytics. Nevertheless, both methods are prone to errors: questionnaires may give superficial answers due to lack of time or motivation, while learning analytics do not reflect offline learning behavior. This paper proposes an alternative approach to classify students' learning styles by integrating eye tracking in combination with Machine Learning (ML) algorithms. Incorporating eye tracking technology into the classification process eliminates the potential problems arising from questionnaires or learning analytics by providing a more objective and detailed analysis of the subject's behavior. Moreover, this approach allows for a deeper understanding of subconscious processes and provides valuable insights into the individualized learning preferences of students. In order to demonstrate this approach, an eye tracking study is conducted with 117 participants using the Tobii Pro Fusion. Using qualitative and quantitative analyses, certain patterns in the subjects' gaze behavior are assigned to their learning styles given by the validated Index of Learning Styles (ILS) questionnaire. In short, this paper presents an innovative solution to the challenges associated with classifying students' learning styles. By combining eye tracking data with ML algorithms, an accurate and insightful understanding of students' individual learning paths can be achieved, ultimately leading to improved educational outcomes and reduced dropout rates. Y1 - 2023 SN - 978-84-09-55942-8 U6 - https://doi.org/10.21125/iceri.2023.1291 N1 - Zugehöriges Datenset: https://doi.org/10.5281/zenodo.8349468 SP - 5153 EP - 5162 PB - IATED ER - TY - GEN A1 - Hipp, Susanne T1 - Small antennas in huge environments - simulation using hybrid methods T2 - Workshop des ITG-Fachausschuss HF1: Innovative Beamforming Antennas Y1 - 2022 ER - TY - CHAP A1 - Rasp, Franziska A1 - Eberlein, Ernst A1 - Perner, Bastian A1 - Roth-Mandutz, Elke A1 - Hipp, Susanne T1 - Enhanced 5G Sidelink Ranging Based on Carrier Aggregation T2 - 2023 13th International Conference on Indoor Positioning and Indoor Navigation (IPIN), Nuremberg, Germany, 25-28 September 2023 N2 - Radio access network based positioning and ranging technologies become more and more important for autonomous driving. Positioning on the 5G Sidelink (SL) is discussed in Release 18 (2022-2024) of the Third Generation Partnership Project. For accurate timing-based ranging, a high temporal and spatial resolution is fundamental. The bandwidth for 5G SL positioning is limited due to sharing the existing SL resources with communication. Therefore, we send the positioning reference signal on two separate Component Carriers, i.e. we use a fragmented spectrum. We introduce a two step algorithm for estimating the time of arrival using the inflection point method. We proved a fragmented spectrum can achieve the same accuracy as a continuous spectrum. KW - Sidelink KW - 5G mobile communications KW - Distance measurement KW - Ranging KW - Positioning Y1 - 2023 SN - 9798350320114 U6 - https://doi.org/10.1109/IPIN57070.2023.10332548 SP - 1 EP - 6 PB - IEEE ER - TY - JOUR A1 - Lohmeyer, Manfred A1 - Shamonin (Chamonine), Mikhail A1 - Hertel, Peter T1 - Integrated optical circulator based on radiatively coupled magneto-optic waveguides JF - Optical Engineering N2 - In a three-guide coupler with multimode central waveguide, more than two modes of the entire structure participate in the coupling between the outer waveguides. Using a three-mode approximation we found simple conditions for complete power transfer between the outer waveguides: the device length has to match certain multiples of the con- ventionally defined coupling length. The specific form of the relevant modes allows us to design a magneto-optic isolator or circulator with significantly reduced device length (as compared to the conventional nonreciprocal coupler). The performance of the proposed devices is simulated by propagating-mode calculations. Estimates for admissible fabrication tolerances for the layer thicknesses are presented. KW - integrated optics KW - magneto-optic circulator KW - magneto-optic isolator KW - radiatively coupled waveguides KW - three-guide coupler Y1 - 1997 U6 - https://doi.org/10.1117/1.601255 VL - 36 IS - 3 SP - 889 EP - 895 PB - SPIE 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 - JOUR A1 - Pozzobon, Enrico A1 - Weiß, Nils A1 - Mottok, Jürgen A1 - Matoušek, Václav T1 - An evolutionary fault injection settings search algorithm for attacks on safe and secure embedded systems JF - Neural Network World (NNW) Y1 - 2023 U6 - https://doi.org/10.14311/NNW.2023.33.020 VL - 33 IS - 5 SP - 357 EP - 374 PB - Czech Technical University in Prague ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Lohmeyer, Manfred A1 - Hertel, Peter T1 - Directional coupler based on radiatively coupled waveguides JF - Applied optics (Appl. Opt.) N2 - 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. Y1 - 1997 UR - https://opg.optica.org/ao/abstract.cfm?URI=ao-36-3-635 U6 - https://doi.org/10.1364/ao.36.000635 VL - 36 IS - 3 SP - 635 EP - 641 ER - TY - JOUR A1 - Lohmeyer, Manfred A1 - Shamonin (Chamonine), Mikhail A1 - Bahlmann, N. A1 - Hertel, Peter A1 - Dotsch, H. T1 - Radiatively Coupled Waveguide Concept for an Integrated Magneto-Optic Circulator JF - MRS Online Proceedings Library N2 - 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. Y1 - 1998 U6 - https://doi.org/10.1557/PROC-517-519 SN - 1946-4274 IS - 517 SP - 519 EP - 524 ER - TY - JOUR A1 - Lohmeyer, Manfred A1 - Shamonin (Chamonine), Mikhail A1 - Hertel, Peter T1 - Boundary conditions for the finite difference beam propagation method based on plane wave solutions of the Fresnel equation JF - IEEE Journal of Quantum Electronics N2 - 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. KW - Boundary conditions KW - Finite difference methods KW - Optical propagation KW - Matrix decomposition KW - Computational modeling KW - Refractive index KW - Maxwell equations KW - Sparse matrices KW - Partial differential equations KW - Shape Y1 - 1997 U6 - https://doi.org/10.1109/3.552269 SN - 0018-9197 VL - 33 IS - 2 SP - 279 EP - 286 ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Lohmeyer, Manfred A1 - Hertel, Peter T1 - Analysis of power-dependent switching between radiatively coupled planar waveguides JF - Journal of Lightwave Technology N2 - 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. KW - Electromagnetic coupling KW - Planar waveguide KW - Optical waveguides KW - Nonlinear optics KW - Optical coupling KW - Optical surface waves KW - Optical refraction KW - Optical variables control KW - Refractive index KW - Optical switches Y1 - 1997 UR - 1558-2213 U6 - https://doi.org/10.1109/50.588671 VL - 15 IS - 6 SP - 983 EP - 989 PB - IEEE CY - New York ER - TY - CHAP A1 - Reindl, Andrea A1 - Lausser, Florian A1 - Eriksson, Lars A1 - Park, Sangyoung A1 - Niemetz, Michael A1 - Meier, Hans ED - Pinker, Jiří T1 - Control Oriented Mathematical Modeling of a Bidirectional DC-DC Converter - Part 1: Buck Mode T2 - 28th International Conference on Applied Electronics (AE) 2023, Pilsen, 6-7 September 2023 N2 - Parallel connection of different batteries equipped with bidirectional DC-DC converters offers an increase of the total storage capacity, the provision of higher currents and an improvement of reliability and system availability. To share the load current among the DC-DC converters while maintaining the safe operating range of the batteries, appropriate controllers are needed. The basis for the design of these control approaches requires knowledge of both the static and dynamic characteristics of the DC-DC converter used. In this paper, the small signal analysis of a DC-DC converter in buck mode is shown using the circuit averaging technique. The paper gives an overview of all required transfer functions:. The control and line to output transfer functions for CCM and DCM relevant for average current mode control as well as for voltage control are derived and their poles and zeros are determined. This provides the basis for stability consideration, analysis of the overall control structure and controller design. KW - Analytical models KW - Average modeling KW - Batteries KW - bidirectional dc-dc converter KW - buck mode KW - circuit-averaging technique KW - continuous conduction mode KW - DC-DC power converters KW - derivation of transfer functions KW - discontinuous conduction mode KW - half-bridge KW - Mathematical models KW - Reliability KW - Signal analysis KW - small signal analysis KW - Stability analysis Y1 - 2023 SN - 979-8-3503-3554-5 U6 - https://doi.org/10.1109/AE58099.2023.10274168 SP - 1 EP - 7 PB - University of West Bohemia CY - Pilsen ER - TY - JOUR A1 - Maier, Robert A1 - Grabinger, Lisa A1 - Urlhart, David A1 - Mottok, Jürgen T1 - Causal Models to Support Scenario-Based Testing of ADAS JF - IEEE Transactions on Intelligent Transportation Systems N2 - 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. KW - automated driving systems KW - Automation KW - Bayesian networks KW - Causal inference KW - Data models KW - ISO Standards KW - model-based testing KW - Safety KW - Task analysis KW - Testing KW - Vehicles Y1 - 2023 U6 - https://doi.org/10.1109/TITS.2023.3317475 SN - 1524-9050 SP - 1 EP - 17 PB - IEEE ER - TY - JOUR A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Mottok, Jürgen T1 - On the perception of graph layouts JF - Journal of Software: Evolution and Process N2 - In the field of software engineering, graph-based models are used for a variety of applications. Usually, the layout of those graphs is determined at the discretion of the user. This article empirically investigates whether different layouts affect the comprehensibility or popularity of a graph and whether one can predict the perception of certain aspects in the graph using basic graphical laws from psychology (i.e., Gestalt principles). Data on three distinct layouts of one causal graph is collected from 29 subjects using eye tracking and a print questionnaire. The evaluation of the collected data suggests that the layout of a graph does matter and that the Gestalt principles are a valuable tool for assessing partial aspects of a layout. KW - causal graphs KW - eye tracking KW - gestalt principles KW - graph layouts KW - modeling languages Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-62973 N1 - Corresponding author: Lisa Grabinger PB - Wiley ER - TY - CHAP A1 - Reindl, Andrea A1 - Wetzel, Daniel A1 - Niemetz, Michael A1 - Meier, Hans T1 - Leader Election in a Distributed CAN-Based Multi-Microcontroller System T2 - 2023 3rd International Conference on Electrical, Computer, Communications and Mechatronics Engineering (ICECCME), 19-21 July 2023, Tenerife, Canary Islands, Spain N2 - In a distributed system, functionally equivalent nodes work together to form a system with improved availability, reliability and fault tolerance. Thereby, the purpose is to achieve a common control objective. As multiple components cooperate to accomplish tasks, coordination between them is required. Electing a node as the temporary leader can be a possible solution to perform coordination. This work presents a self-stabilizing algorithm for the election of a leader in dynamically reconfigurable bus topology-based broadcast systems with a message and time complexity of O(1). The election is performed dynamically, i.e., not only when the leader node fails, and is criterion-based. The criterion used is a performance related value which evaluates the properties of the node regarding the ability to perform the tasks of the leader. The increased demands on the leader are taken into account and a re-election is started when the criterion value drops below a predefined level. The goal here is to distribute the load more evenly and to reduce the probability of failure due to overload of individual nodes. For improved system availability and reduced fault rates, a management level consisting of leader, assistant and co-assistant is introduced. This reduces the number of required messages and the duration in case of non-initial election. For further reduction of required messages to uniquely determine a leader, the CAN protocol is exploited. The proposed algorithm selects a node with an improved failure rate and a reduced message and hence time complexity while satisfying the safety and termination constraints. The operation of the algorithm is validated using a hardware test setup. KW - broadcast communication KW - computational complexity KW - controller area networks KW - coordination KW - decentralized applications KW - distributed systems KW - failure analysis KW - Fault tolerance KW - fault tolerant computing KW - Fault tolerant systems KW - Hardware KW - Heuristic algorithms KW - Leader election KW - load balancing KW - Mechatronics KW - message complexity KW - microcontrollers KW - performance related election KW - probability KW - Protocols KW - self-stabilization KW - telecommunication network topology KW - Voting Y1 - 2023 SN - 979-8-3503-2297-2 U6 - https://doi.org/10.1109/ICECCME57830.2023.10252250 SP - 1 EP - 8 PB - IEEE CY - Piscataway, NJ, USA ER - TY - JOUR A1 - Kravanja, Gaia A1 - Kriegl, Raphael A1 - Hribar, Luka A1 - Glavan, Gašper A1 - Drevenšek‐Olenik, Irena A1 - Shamonin (Chamonine), Mikhail A1 - Jezeršek, Matija T1 - Magnetically Actuated Surface Microstructures for Efficient Transport and Tunable Separation of Droplets and Solids JF - Advanced Engineering Materials N2 - Efficient transportation of droplets (∽10 ¹ ̶̶̶̶ 10 ² µl) and small solid objects (∽10 ¹ ̶ 10 ² mm ³ ) have important applications in many fields, such as microfluidics, lab‐on‐a‐chip devices, drug delivery, etc. A novel multifunctional surface consisting of a periodic array of micro‐lamellae from a soft magnetoactive elastomer (MAE) on a plastic substrate is reported for these purposes. The physical origin of the propulsion is the bending of soft magnetic lamellae in non‐uniform magnetic fields, which is also observed in uniform magnetic fields. The magnetoactive surface is fabricated using a facile and rapid method of laser ablation. The propulsion of items is realized using a four‐pole rotating magnet. This results in a cyclic lamellar fringe motion over the micro‐structured surface and brings an advantage of easy reciprocation of transport by rotation reversal. Two modes of object transportation are identified: “pushing” mode for precise control of droplet and solid positioning and “bouncing” mode for heavier solid objects transportation. A water droplet of 5 μl or a glass sphere with a 2.1 mm diameter can be moved at a maximum speed of 60 mm s ⁻¹ . The multifunctionality of the proposed mechatronic platform is demonstrated on the examples of selective solid‐liquid separation and droplet merging. KW - Keywordslaser micromachinings KW - magnetoactive elastomers KW - magnetoresponsivesurfaces KW - object separations KW - object transportations Y1 - 2023 U6 - https://doi.org/10.1002/adem.202301000 SN - 1527-2648 VL - 25 IS - 22 SP - 1 EP - 11 PB - Wiley-VCH ER - TY - CHAP A1 - Bittner, Dominik A1 - Hendricks, Ricky-Ricardo A1 - Horn, Luca A1 - Mottok, Jürgen T1 - In-depth Benchmarking of Transfer Learning Techniques for Improved Bottle Recognition T2 - 2023 IEEE 13th International Conference on Pattern Recognition Systems (ICPRS), Guayaquil, Ecuador, 04-07 July 2023 N2 - An immense diversity in bottle types requires high accuracy during sorting for recycling purposes by breweries. This extremely complex and time-consuming procedure can result in enormous additional costs for them. This paper presents transfer learning-based algorithms for classifying beer bottle brands using camera images, applicable in individual sorting solutions for different use cases. The problem is tackled using customised EfficientNet, InceptionResNet and VGG models along with an augmented dataset. In addition, a detailed analysis of different model and parameter combinations is performed, enabling tailor-made technologies for specific conditions and resource limitations. In accompanying validations and subsequent tests, a test accuracy of 100% in the recognition of beer brands could be achieved, proving the proposed method fully contributes to the solution of the problem. KW - Analytical models KW - Costs KW - Transfer learning KW - Benchmark testing KW - Cameras KW - Pattern recognition KW - Recycling Y1 - 2023 SN - 979-8-3503-3337-4 U6 - https://doi.org/10.1109/ICPRS58416.2023.10178995 SP - 1 EP - 6 PB - IEEE ER - TY - CHAP A1 - Schaller, R. A1 - Maier, F. A1 - Mandl, Roland T1 - Thermally stimulated depolarization current - characterization of a multi-layer dielectric stack for semiconductor packages T2 - 2022 14th International Conference on Advanced Semiconductor Devices and Microsystems (ASDAM), 23-26 October 2022, Smolenice Castle, Slovakia N2 - In this paper, the results of Thermally Stimulated Depolarization Currents (TSDC)-measurements of a complex system of stacked dielectric layers, like typically appearing in semiconductor packages, is presented. Characteristics of the individual isolation layers are presented solely and the results are compared to the stack. The investigated layers are comprising polyimide film, alkali-free glass, polyolefin film and epoxy based mold compound. Measurements have been carried out in the temperature range from 19 - 195°C at varying polarization fields for every material. Various relaxation peaks, originated by different polarization mechanisms within the materials could be observed. A comparison between the TSDC-peaks of the layer stack and the individual materials is shown. Our results demonstrate, that the super positioned spectrum is getting dominated by a single portion, the mold compound. KW - Glass KW - Micromechanical devices KW - Polyimides KW - Semiconductor device measurement KW - Semiconductor devices KW - Temperature distribution KW - Temperature measurement Y1 - 2022 SN - 978-1-6654-6977-7 U6 - https://doi.org/10.1109/ASDAM55965.2022.9966799 SP - 1 EP - 5 PB - IEEE ER - TY - JOUR A1 - Kriegl, Raphael A1 - Kovalev, Alexander A1 - Shamonin (Chamonine), Mikhail A1 - Gorb, Stanislav T1 - Tunable contact angle hysteresis on compliant magnetoactive elastomers JF - Extreme Mechanics Letters N2 - It is shown that the advancing (ACA) and receding (RCA) contact angles of water on extremely soft (shear modulus of the order of 10 kPa) magnetoactive elastomer (MAE) films significantly depend on the applied magnetic field. The difference between these angles, known as the contact angle hysteresis, is examined. The roles of the filler concentration and material softness are elaborated. The highest change in the contact angle hysteresis (CAH) from 34° in the absence of magnetic field to 76° in a magnetic field of 0.4 T is achieved for the softest sample with the lowest mass fraction of iron particles (70 wt%). The dependence of the CAH on magnetization history (“magnetic hysteresis”) is observed. This magnetic hysteresis is clearly pronounced for the ACA and has little effect on the RCA. Magnetic field-induced changes of the surface roughness exhibit qualitatively the same hysteresis behavior with regard to the external magnetic field as the ACA. The results are promising for the development of smart surfaces for applications where the dynamic wetting has to be controlled. KW - Magnetoactive elastomers KW - Dynamic wetting KW - Magnetic hysteresis KW - Contact angle hysteresis Y1 - 2023 U6 - https://doi.org/10.1016/j.eml.2023.102049 SN - 2352-4316 VL - 63 PB - Elsevier ER - TY - JOUR A1 - Petchartee, Somrak A1 - Monkman, Gareth J. T1 - Pre-slip sensing using tactile sensor JF - Annals Universitaria Criaiova-Series: Automation, Computers, Electronics and Mechatronics Y1 - 2007 VL - 4 (31) IS - 2 SP - 109 EP - 114 ER - TY - CHAP A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Mottok, Jürgen A1 - Gruber, Hans T1 - Visual Expertise in Code Reviews: Using Holistic Models of Image Perception to Analyze and Interpret Eye Movements T2 - ETRA '23: 2023 Symposium on Eye Tracking Research and Applications, Tubingen Germany 30 May 2023- 2 June 2023 N2 - This study uses holistic models of image perception to analyze and interpret eye movements during a code review. 23 participants (15 novices and 8 experts) take part in the experiment. The subjects’ task is to review six short code examples in C programming language and identify possible errors. During the experiment, their eye movements are recorded by an SMI 250 REDmobile. Additional data is collected through questionnaires and retrospective interviews. The results implicate that holistic models of image perception provide a suitable theoretical background for the analysis and interpretation of eye movements during code reviews. The assumptions of these models are particularly evident for expert programmers. Their approach can be divided into different phases with characteristic eye movement patterns. It is best described as switching between scans of the code example (global viewing) and the detailed examination of errors (focal viewing). Y1 - 2023 U6 - https://doi.org/10.1145/3588015.3589189 SP - 1 EP - 7 PB - ACM ER - TY - THES A1 - Marterer, Verena T1 - A Characterisation of Motives and Barriers to Taking up Academic Study in the Field of Electrical Engineering N2 - 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. Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-62550 CY - Regensburg ER - TY - CHAP A1 - Nadimpalli, Vamsi Krishna A1 - Hauser, Florian A1 - Bittner, Dominik A1 - Grabinger, Lisa A1 - Staufer, Susanne A1 - Mottok, Jürgen ED - Mottok, Jürgen T1 - Systematic Literature Review for the Use of AI Based Techniques in Adaptive Learning Management Systems T2 - Proceedings of the 5th European Conference on Software Engineering Education, Seeon/Germany, June 19 - 21, 2023 N2 - Nowadays, learning management systems are widely employed in all educational institutions to instruct students as a result of the increasing in online usage. Today’s learning management systems provide learning paths without personalizing them to the characteristics of the learner. Therefore, research these days is concentrated on employing AI-based strategies to personalize the systems. However, there are many different AI algorithms, making it challenging to determine which ones are most suited for taking into account the many different features of learner data and learning contents. This paper conducts a systematic literature review in order to discuss the AI-based methods that are frequently used to identify learner characteristics, organize the learning contents, recommend learning paths, and highlight their advantages and disadvantages. Y1 - 2023 SN - 978-1-4503-9956-2 U6 - https://doi.org/10.1145/3593663.3593681 SP - 83 EP - 92 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - Schächinger, J. A1 - Brückl, Oliver A1 - Becker, Mark A1 - Lechner, Raphael T1 - Results of the Research Project Optibiosy: Biogas plants as stabilizers of the power system? JF - BWK ENERGIE T2 - Biogasanlagen als Stabilisatoren des Stromsystems? Y1 - 2022 SN - 1436-4883 VL - 74 IS - 11-12 SP - 34 EP - 39 PB - VDI-Verlag CY - Düsseldorf 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 - Grabinger, Lisa A1 - Hauser, Florian A1 - Mottok, Jürgen T1 - Evaluating Graph-based Modeling Languages T2 - Proceedings of the 5th European Conference on Software Engineering Education, Seeon/Germany, June 19 - 21, 2023 N2 - As humans, we tend to use models to describe reality. Modeling languages provide the formal frameworks for creating such models. Usually, the graphical design of individual model elements is based on subjective decisions; their suitability is determined at most by the prevalence of the modeling language. With other words: there is no objective way to compare different designs of model elements. The present paper addresses this issue: it introduces a systematic approach for evaluating the elements of graph-based modeling languages comprising 14 criteria – derived from standards, usability analyses, or the design theories ‘Physics of Notations’ and ‘Cognitive Dimensions of Notations’. The criteria come with measurement procedures and evaluation schemes based on reasoning, eye tracking, and questioning. The developed approach is demonstrated with a specific use case: three distinct sets of node elements for causal graphs are evaluated in an eye tracking study with 41 subjects. Y1 - 2023 SN - 978-1-4503-9956-2 U6 - https://doi.org/10.1145/3593663.3593664 SP - 120 EP - 129 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 - 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 - Hauser, Florian A1 - Grabinger, Lisa A1 - Mottok, Jürgen T1 - Something Short Gets Even Shorter: Adapting the LIST-K for the Use in an Online Learning Management System T2 - Proceedings of the 5th European Conference on Software Engineering Education, Seeon/Germany, June 19 - 21, 2023 N2 - This study examines how Klingsieck’s LIST-K questionnaire [22] can be shortened and adapted to the requirements of an online learning management system. In a study with 213 participants, the questionnaire is subjected to an exploitative factor analysis. In a next step, the results are evaluated in terms of their reliability. This process creates a modified factor structure for the LIST-K, comprising a total of eight factors. The reliability of the modified questionnaire is at an α of .770. The shortened version of the LIST-K questionnaire is currently being used on an experimental basis in different courses. Y1 - 2023 SN - 978-1-4503-9956-2 U6 - https://doi.org/10.1145/3593663.3593684 SP - 65 EP - 72 PB - ACM ER - TY - CHAP A1 - Homann, Alexander A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Mottok, Jürgen T1 - An Eye Tracking Study on MISRA C Coding Guidelines T2 - ECSEE '23: Proceedings of the 5th European Conference on Software Engineering Education, Seeon/Germany, June 19 - 21, 2023 N2 - C is one of the most widely used programming languages - MISRA C is one of the most known sets of coding guidelines for C. This paper examines the usefulness and comprehensibility of the MISRA C:2012 guidelines in an eye tracking study. There, subjects encounter non-compliant code in four different code review settings: with no additional reference, with an actual MISRA C guideline, with a case-specific interpretation of a MISRA C guideline, and with a compliant version of the code. The data collected was analyzed not only in terms of the four presentation styles, but also by dividing the subjects into experience levels based on their semesters of study or years of work experience. Regarding the difference between actual and interpreted guidelines, we found that for interpreted guidelines the error detection rate is higher whereas the duration and frequency of visits to the guideline itself are mainly lower. This suggest that the actual guidelines are less useful and more difficult to understand. The former is contradicted by the subjects’ opinions: when surveyed, they rated the usefulness of the actual guidelines higher. Y1 - 2023 SN - 978-1-4503-9956-2 U6 - https://doi.org/10.1145/3593663.3593671 SP - 130 EP - 137 PB - ACM ER - TY - JOUR A1 - Jezeršek, Matija A1 - Kriegl, Raphael A1 - Kravanja, Gaia A1 - Hribar, Luka A1 - Drevenšek‐Olenik, Irena A1 - Unold, Heiko A1 - Shamonin (Chamonine), Mikhail T1 - Control of Droplet Impact through Magnetic Actuation of Surface Microstructures JF - Advanced Materials Interfaces N2 - An effective method for on-demand control over the impact dynamics of droplets on a magnetoresponsive surface is reported. The surface is comprised of micrometer-sized lamellas from a magnetoactive elastomer on a copper substrate. The surface itself is fabricated using laser micromachining. The orientation of the lamellae is switched from edge-on (orthogonal to the surface) to face-on (parallel to the surface) by changing the direction of a moderate (<250 mT) magnetic field. This simple actuation technique can significantly change the critical velocities of droplet rebound, deposition, and splashing. Rebound and deposition regimes can be switched up to Weber number We < 13 ± 3, while deposition and splashing can be switched in the range of 32 < We < 52. Because a permanent magnet is used, no permanent power supply is required for maintaining the particular regime of droplet impact. The presented technology is highly flexible and enables selective fabrication and actuation of microstructures on complex devices. It has great potential for applications in soft robotics, microfluidics, and advanced thermal management. Y1 - 2023 U6 - https://doi.org/10.1002/admi.202202471 VL - 10 IS - 11 PB - Wiley ER - TY - CHAP A1 - Fuhrmann, Thomas A1 - Niemetz, Michael T1 - Ideas on Digitally Supported Individualization of Teaching and Learning for Evolving Competency Requirements T2 - Ninth International Conference on Higher Education Advances (HEAd 23), València, June 19, 2023 – June 22, 2023 N2 - The world is changing rapidly, mainly due to the digitalization of all areas of living. A huge amount of information is accessible via the Internet, and since it is no longer possible for individual humans to keep track of it, artificial intelligence (AI) is analyzing this data. In this rapidly changing world, students have to be educated for a successful career during their whole working life. These boundary conditions lead to completely new challenges for the education of students that are unprecedented in this form. Digitalization in education can help to cope with these challenges but can only be a means, not a goal. Personal interaction with students remains the most important task in education to address individual weaknesses and further develop strengths and talents. With the increasing amount of openly available information and the consequently increasing diversity of experiences within the group of students, differentiation is advancing to become the key to successful education. Digitization can help with this challenging task and support communication between students and their experienced instructors. But computers cannot replace human interaction and attempts to improve teaching efficiency by replacing this communication with electronic means endangers the learning success for complex concepts. This article analyzes education demands and possibilities for digitally supported teaching and learning. KW - Digitalization KW - higher education KW - student competencies KW - differentiation Y1 - 2023 U6 - https://doi.org/10.4995/HEAd23.2023.16232 SN - 2603-5871 SP - 1399 EP - 1406 PB - Universitat Polit`ecnica de Val`encia ER - TY - JOUR A1 - De, Sangita A1 - Premek, Brada A1 - Mottok, Jürgen T1 - Derivation of Optimized Threshold of Semantic Alignment Metrics for Intepretation of Interoperability and Reusability of Cross-enterprise Vehicle Service Interface Models JF - Informatica N2 - Over the past decade, cars have turned gradually into real cyber physical systems. The collaboration of services between the service-oriented, cross-enterprise vehicle application frameworks has increased to generate novel, smart and complicated vehicle services. Consequently, from an interoperability perspective, semantically mapping of vehicle service component’s interface ontological models emerged as a big research interest in automotive application domain that manipulates several cross-enterprise synergy knowledge applications frameworks. The ontological metamodeling lays the foundation for building semantic bridge and exploring semantic associations between service components’ interface models based on the domain knowledge for semantic interoperability. Also, several semantic quality metrics has been defined over time for the vehicle service interface ontological metamodels. The empirically evaluated values of these metrics can be used to assess progress in cross-enterprise interoperability between the service and the clients’ APIs ontological models in vehicle domain. Despite potential benefits of semantic alignment quality metrics, the effective use of these metrics for vehicle service interface ontologies have proven elusive. Yes, such metrics can be used successfully for quantification, but then they mostly fail to provide adequate annotations in subsequent decision-making in the direction of semantic interoperability and reusability. The effective use of ontology semantic alignment quality metrics is basically hindered in the absence of the meaningful thresholds. In fact, the absence of an effective and meaningful threshold for the semantic similarity measure between various vehicle service interface ontological metamodels, motivates this research work which not only proposes a design approach to an optimized threshold for the semantic similarity metrics but also applies this threshold on few defined semantic alignment quality metrics. This paper also uses a real-world vehicle domain industrial case study to illustrate the design approach. KW - interface KW - automotive services KW - semantic KW - metrics KW - optimized threshold KW - framework KW - metamodels KW - ontologies Y1 - 2023 U6 - https://doi.org/10.31449/inf.v47i7.4739 SN - 0350-5596 VL - 47 IS - 7 PB - Slovenian Society Informatika ER - TY - JOUR A1 - Glavan, Gašper A1 - Belyaeva, Inna A. A1 - Drevenšek‐Olenik, Irena A1 - Shamonin (Chamonine), Mikhail T1 - Experimental study of longitudinal, transverse and volume strains of magnetoactive elastomeric cylinders in uniform magnetic fields JF - Journal of Magnetism and Magnetic Materials N2 - Magnetoactive elastomers (MAEs) are promising materials for realization of magnetic field-controlled soft actuators. Herein, a systematic investigation of magnetic field-induced macroscopic deformations of soft MAE cylinders with a diameter of 15 mm in uniform quasi-static magnetic fields directed parallel to the cylinder’s axis is reported. The measurements were based on image processing. Thirty-six MAE samples differing in the weight fraction of the iron filler (70 wt%, 75 wt% and 80 wt%), alignment of filling particles, and the aspect ratio (0.2, 0.4, 0.6, 0.8, 1.0 and 1.2) were fabricated. MAE cylinders exhibited high relative change in height (up to 35% in the field of 485 kA/m) and lateral contraction. The dependence of the maximum extensional strain on the aspect ratio was obtained and compared with theoretical considerations. A concave dent was formed on the free circular base in magnetic fields. This concavity was characterized experimentally. A significant volumetric strain of the order of magnitude of 10% was calculated in MAEs for the first time. In consequently repeated magnetization cycles, the remanent extensional strain significantly increased after each cycle. The results are qualitatively discussed in the framework of the modern views on the magnetically induced macroscopic deformations of MAEs. The directions of further research are outlined. Y1 - 2023 U6 - https://doi.org/10.1016/j.jmmm.2023.170826 SN - 0304-8853 VL - 579 PB - Elsevier 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 - JOUR A1 - Schiek, Roland T1 - Nonlinear refractive index in silica glass JF - Optical Materials Expres N2 - The third-order nonlinear susceptibility of silica glass is measured via self-phase modulation in standard single mode fibers at a wavelength of 1550 nm. To minimize the influence of polarization state changes along the propagation only meter-long fibers were investigated. With pulse durations of picoseconds a quasi-instantaneous nonlinearity with ultrafast electronic and fast nuclear-vibration contributions produces under conditions of negligible dispersion a classic and clean nonlinear phase shift following exactly the shape of the pulse power. The complex pulse envelope was retrieved from frequency optical gating spectrograms. The nonlinear fiber parameter γ could be determined with an accuracy of 3.7 percent. Considering the mode field structure and the doping influence the nonlinear refractive index of silica glass as the fiber base material was found to be n 2 =2.22⋅10 −16 cm 2 W±6.0% for picosecond-long pulses. Comparing nonlinear phase shifts from linear and circular polarized light a nuclear-vibration contribution to the cubic fiber nonlinearity of 25 percent was estimated. Y1 - 2023 U6 - https://doi.org/10.1364/ome.489520 N1 - Corresponding author: Roland Schiek VL - 13 IS - 6 SP - 1727 EP - 1740 PB - Optica ER - TY - JOUR A1 - Straus, Izidor A1 - Kokot, Gašper A1 - Kravanja, Gaia A1 - Hribar, Luka A1 - Kriegl, Raphael A1 - Shamonin (Chamonine), Mikhail A1 - Jezeršek, Matija A1 - Drevenšek‐Olenik, Irena T1 - Dynamically tunable lamellar surface structures from magnetoactive elastomers driven by a uniform magnetic field JF - Soft Matter N2 - Stimuli responsive materials are key ingredients for any application that requires dynamically tunable or on-demand responses. In this work we report experimental and theoretical investigation of magnetic-field driven modifications of soft-magnetic elastomers whose surface was processed by laser ablation into lamellar microstructures that can be manipulated by a uniform magnetic field. We present a minimal hybrid model that elucidates the associated deflection process of the lamellae and explains the lamellar structure frustration in terms of dipolar magnetic forces arising from the neighbouring lamellae. We experimentally determine the magnitude of the deflection as a function of magnetic flux density and explore the dynamic response of lamellae to fast changes in a magnetic field. A relationship between the deflection of lamellae and modifications of the optical reflectance of the lamellar structures is resolved. KW - Intelligente Materialien Y1 - 2023 U6 - https://doi.org/10.1039/D3SM00012E VL - Vol. 19 SP - 3357 EP - 3365 PB - Royal Society of Chemistry ER - TY - CHAP A1 - Petchartee, Somrak A1 - Monkman, Gareth J. T1 - Optimisation of Prehension Force through Tactile Sensing T2 - Proc. International Conference on Engineering & ICT 2007 (ICEI 2007), Malaysia Y1 - 2007 ER - TY - JOUR A1 - Petchartee, Somrak A1 - Monkman, Gareth J. T1 - Optimisation of Prehension Force through Tactile Sensing JF - Journal of Advanced Manufacturing Technology Y1 - 2007 SN - 2289-8107 PB - Universiti Teknikal Malaysia Melaka ER - TY - CHAP A1 - Forster, Eva A1 - Mayer, Matthias A1 - Rabindranath, Raman A1 - Bentz, Alexander A1 - Böse, Holger A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. T1 - Surface Control Magneto-Active Polymers (MAP) T2 - EuroEAP 2011, First international conference on Electromechanically Active Polymer (EAP) transducers & artificial muscles, Pisa, 8-9 June N2 - 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. Y1 - 2011 ER - TY - JOUR A1 - Bakaev, V. V. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail T1 - The permeability and remanent magnetization of a randomly inhomogeneous two-phase medium JF - Technical Physics N2 - A randomly inhomogeneous composite consisting of two, ferromagnetic and nonmagnetic (para-or diamagnetic), phases is considered. The dependence of the effective permeability of the composite on the concentration of the ferromagnetic phase and on the applied magnetic field is found for the case of the negligible hysteresis loop. When the hysteresis loop is appreciable, the remanent magnetization as a function of the ferromagnet concentration is calculated. KW - Magnetic Field KW - Permeability KW - Hysteresis Loop KW - Remanent Magnetization KW - Applied Magnetic Field Y1 - 2002 U6 - https://doi.org/10.1134/1.1435901 VL - 47 SP - 125 EP - 128 PB - Springer ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Zhenirovskyy, M. I. A1 - Shamonin (Chamonine), Mikhail T1 - The effective properties of macroscopically nonuniform ferromagnetic composites: Theory and numerical experiment JF - Journal of Experimental and Theoretical Physics N2 - Various theoretical models (self-consistent field, local linearization, and percolation theory methods and an analytic solution of the linear problem for an ordered medium) for calculating the magnetostatic properties of two-phase composites containing one ferromagnetic phase were considered. The concentration and field dependences of the effective magnetic permeability were found. A method for determining the coercive force and remanent magnetization as functions of the ferromagnetic phase concentration was suggested. Numerical experiments were performed for composites with a periodic distribution of circular inclusions. The results were compared with the analytically calculated effective magnetic permeability. KW - Numerical Experiment KW - Remanent Magnetization KW - Field Dependence KW - Coercive Force KW - Magnetic Permeability Y1 - 2003 U6 - https://doi.org/10.1134/1.1545385 VL - 96 SP - 66 EP - 77 PB - Springer ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Snarskii, Andrei A. A1 - Zhenirovskyy, M. I. T1 - Effective magnetic permeability of ferromagnetic composites. Theoretical description and comparison with experiment JF - NDT & E International N2 - Two analytical methods based on the so-called local linearization of magnetostatic properties of composite materials with ferromagnetic inclusions in a non-magnetic matrix are described. These methods are applied to the experimental data obtained in Gorkunov et al. [Russ. J. Nondestruct. Test. 3 (2001) 186]. A qualitative agreement is obtained for the concentration values reported in that paper and a quantitative agreement is achieved at slightly different value of concentration. The conclusions are supported by direct numerical modeling. KW - Material characterization KW - Ferromagnetic composites KW - Magnetostatic properties Y1 - 2004 U6 - https://doi.org/10.1016/j.ndteint.2003.08.001 VL - 37 IS - 1 SP - 35 EP - 40 PB - Elsevier ER - TY - JOUR A1 - Filippov, O. A1 - Ringhofer, K. H. A1 - Shamonin (Chamonine), Mikhail A1 - Shamonina, Ekaterina A1 - Kamshilin, A. A. A1 - Nippolainen, E. A1 - Sturman, B. I. T1 - Polarization properties of light-induced scattering in Bi12TiO20 crystals: theory and experiment for diagonal geometry JF - Journal of the Optical Society of America B N2 - Illumination of ac-biased photorefractive Bi12TiO20 crystals with a coherent light beam results in the development of strong nonlinear scattering. Theoretically and experimentally we investigate the angular and polarization characteristics of the scattered light for the diagonal ([1̲1̲1]) optical configuration and different polarization states of the pump. A satisfactory understanding of the observed scattering properties is achieved for most of the cases investigated. Y1 - 2003 U6 - https://doi.org/10.1364/JOSAB.20.000677 VL - 20 IS - 4 SP - 677 EP - 684 PB - Optica Publishing Group ER - TY - JOUR A1 - Klank, Michael A1 - Hagedorn, Oliver A1 - Holthaus, Carsten A1 - Shamonin (Chamonine), Mikhail A1 - Dötsch, Horst T1 - Characterization and optimization of magnetic garnet films for magneto-optical visualization of magnetic field distributions JF - NDT & E International N2 - 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. KW - Magneto-optics KW - Imaging KW - Magnetic flux leakage KW - Garnet films Y1 - 2003 U6 - https://doi.org/10.1016/S0963-8695(03)00012-4 VL - 36 IS - 6 SP - 375 EP - 381 PB - Elsevier ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Zhenirovskyy, M. I. T1 - Effective properties of macroscopically non-uniform ferromagnetic composite materials BT - Theory and numerical experiment JF - Zhurnal Eksperimental'noj i Teoreticheskoj Fiziki - Journal of Experimental and Theoretical Physics (JETP) Y1 - 2003 VL - 123 IS - 1 SP - 79 EP - 92 PB - Akademija Nauk SSSR CY - Moscow ER - TY - JOUR A1 - Lukyanets, S. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Bakaev, V. V. T1 - Calculation of magnetic leakage field from a surface defect in a linear ferromagnetic material: an analytical approach JF - NDT & E International N2 - A novel analytical approach for calculating the magnetic leakage field from surface defects is proposed and demonstrated for the case of a linear ferromagnetic material. The novelty of the theory is that it relates the distribution of induced magnetic charges to the surface shape. An excellent agreement between the analytical and numerical results is shown. The functional relations between different magnetic field components are discussed. KW - Magnetic methods KW - Flux leakage KW - Mathematical model KW - Defects Y1 - 2003 U6 - https://doi.org/10.1016/S0963-8695(02)00071-3 VL - 36 IS - 1 SP - 51 EP - 55 PB - Elsevier ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Beuker, T. A1 - Rosen, P. A1 - Klank, Michael A1 - Hagedorn, Oliver A1 - Dötsch, Horst T1 - Feasibility of magneto-optic flaw visualization using thin garnet films JF - NDT & E International N2 - 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. KW - Garnet films KW - Magneto-optics KW - Imaging KW - Flaw visualization KW - Magnetic flux leakage Y1 - 2000 U6 - https://doi.org/10.1016/s0963-8695(00)00028-1 VL - 33 IS - 8 SP - 547 EP - 553 PB - Elsevier ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Klank, Michael A1 - Hagedorn, Oliver A1 - Dötsch, Horst T1 - Magneto-optical visualization of metal-loss defects in a ferromagnetic plate: experimental verification of theoretical modeling JF - Applied optics N2 - 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. Y1 - 2001 U6 - https://doi.org/10.1364/ao.40.003182 VL - 40 IS - 19 SP - 3182 EP - 3189 PB - Optica Publishing Group ER - TY - JOUR A1 - Bakaev, V. V. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail T1 - The effective magnetic permeability of a two-phase fibred ferromagnetic composite JF - Technical Physics Y1 - 2001 U6 - https://doi.org/10.1134/1.1427995 VL - 46 IS - 12 SP - 1571 EP - 1574 PB - Springer ER - TY - JOUR A1 - Lukyanets, S. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Bakaev, V. V. T1 - Calculation of magnetic leakage field from a surface defect in a linear ferromagnetic material: an analytical approach JF - NDT & E International N2 - A novel analytical approach for calculating the magnetic leakage field from surface defects is proposed and demonstrated for the case of a linear ferromagnetic material. The novelty of the theory is that it relates the distribution of induced magnetic charges to the surface shape. An excellent agreement between the analytical and numerical results is shown. The functional relations between different magnetic field components are discussed. KW - Magnetic methods KW - Flux leakage KW - Mathematical model KW - Defects Y1 - 2003 U6 - https://doi.org/10.1016/s0963-8695(02)00071-3 VL - 36 IS - 1 SP - 51 EP - 55 PB - Elsevier ER - TY - JOUR A1 - Bakaev, V. V. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail T1 - The permeability and remanent magnetization of a randomly inhomogeneous two-phase medium JF - Technical Physics N2 - A randomly inhomogeneous composite consisting of two, ferromagnetic and nonmagnetic (para-or diamagnetic), phases is considered. The dependence of the effective permeability of the composite on the concentration of the ferromagnetic phase and on the applied magnetic field is found for the case of the negligible hysteresis loop. When the hysteresis loop is appreciable, the remanent magnetization as a function of the ferromagnet concentration is calculated. Y1 - 2002 U6 - https://doi.org/10.1134/1.1435901 VL - 47 IS - 1 SP - 125 EP - 128 PB - Springer ER - TY - JOUR A1 - Filippov, O. A1 - Ringhofer, K. H. A1 - Shamonin (Chamonine), Mikhail A1 - Shamonina, Ekaterina A1 - Kamshilin, A. A. A1 - Nippolainen, E. A1 - Sturman, B. I. T1 - Polarization properties of light-induced scattering in Bi_12TiO_20 crystals BT - theory and experiment for diagonal geometry JF - Journal of the Optical Society of America B N2 - Illumination of ac-biased photorefractive Bi12TiO20 crystals with a coherent light beam results in the development of strong nonlinear scattering. Theoretically and experimentally we investigate the angular and polarization characteristics of the scattered light for the diagonal ([1̲1̲1]) optical configuration and different polarization states of the pump. A satisfactory understanding of the observed scattering properties is achieved for most of the cases investigated. Y1 - 2003 U6 - https://doi.org/10.1364/josab.20.000677 VL - 20 IS - 4 PB - Optica Publishing Group ER - TY - CHAP A1 - Schulz, Irene A1 - Putzger, Jürgen A1 - Niklas, Andreas A1 - Brandt, M. A1 - Jäger, Andreas A1 - Hardt, A. A1 - Knörzer, S. A1 - Hiller, Karl-Anton A1 - Löffler, S. A1 - Schmalz, Gottfried A1 - Danilov, Sergey N. A1 - Giglberger, Stephan A1 - Hirmer, Marion A1 - Ganichev, Sergey D. A1 - Monkman, Gareth J. T1 - PPG signal acquisition and analysis on in vitro tooth model for dental pulp vitality assessmen T2 - 2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg Y1 - 2012 SP - 142 EP - 146 PB - Shaker-Verlag CY - Aachen ER - TY - JOUR A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Achieving Optimal Reactive Power Compensation in Distribution Grids by Using Industrial Compensation Systems JF - Electricity N2 - 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. KW - Blindleistung KW - Blindleistungsmanagement KW - Industriebetriebe KW - Optimal Power Flow KW - Reactive Power Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-59139 N1 - Corresponding author: Johannes Rauch VL - 4 IS - 1 SP - 78 EP - 95 PB - MDPI CY - Basel ER - TY - JOUR A1 - Gärtner, Sebastian A1 - Marx-Schubach, Thomas A1 - Gaderer, Matthias A1 - Schmitz, Gerhard A1 - Sterner, Michael T1 - Techno-Economic Analysis of Carbon Dioxide Separation for an Innovative Energy Concept towards Low-Emission Glass Melting JF - energies N2 - The currently still high fossil energy demand is forcing the glass industry to search for innovative approaches for the reduction in CO2 emissions and the integration of renewable energy sources. In this paper, a novel power-to-methane concept is presented and discussed for this purpose. A special focus is on methods for the required CO2 capture from typical flue gases in the glass industry, which have hardly been explored to date. To close this research gap, process simulation models are developed to investigate post-combustion CO2 capture by absorption processes, followed by a techno-economic evaluation. Due to reduced flue gas volume, the designed CO2 capture plant is found to be much smaller (40 m3 absorber column volume) than absorption-based CO2 separation processes for power plants (12,560 m3 absorber column volume). As there are many options for waste heat utilization in the glass industry, the waste heat required for CO2 desorption can be generated in a particularly efficient and cost-effective way. The resulting CO2 separation costs range between 41 and 42 EUR/t CO2, depending on waste heat utilization for desorption. These costs are below the values of 50–65 EUR/t CO2 for comparable industrial applications. Despite these promising economic results, there are still some technical restrictions in terms of solvent degradation due to the high oxygen content in flue gas compositions. The results of this study point towards parametric studies for approaching these issues, such as the use of secondary and tertiary amines as solvents, or the optimization of operating conditions such as stripper pressure for further cost reductions potential. KW - economic evaluation KW - CO2-separation KW - glass industry KW - oxyfuel KW - methanation KW - power-to-gas Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-53627 N1 - Corresponding author: Sebastian Gärtner VL - 16 IS - 5 SP - 1 EP - 25 PB - MDPI CY - Basel ER - TY - CHAP A1 - Fuhrmann, Thomas T1 - Course Preparation Time Optimization System for Improved Didactic Outcome T2 - 2022 20th International Conference on Information Technology Based Higher Education and Training (ITHET), 07-09 November 2022, Antalya, Turkey N2 - Due to the various demands for lecturers, there is only a limited time to prepare lectures and lab courses. Therefore, it is necessary to invest the time target-oriented for optimal student learning success. A theoretic model is developed to structure course preparation work regarding scientific content, didactic preparation, and course presentation. Model parameters have to be chosen for each course depending on topic complexity, the lecturer’s prior knowledge, and the already available preparation from the prior semesters. With these parameters, a course preparation model for a complete semester is developed. Analytic models for different optimization strategies are introduced according to the overall goal of the lecturer. Numerical optimization is done to find the appropriate course preparation times to reach an optimal course preparation for high student learning success. It is seen that due to the different optimization strategies, the preparation time results vary and no single truth is given. But this optimization system gives hints on how to invest preparation time target-oriented for high student learning success. KW - Higher education KW - Engineering education KW - Course preparation KW - Curriculum development KW - Optimization Y1 - 2022 SN - 978-1-6654-8908-9 U6 - https://doi.org/10.1109/ITHET56107.2022.10031642 PB - IEEE 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 - 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 - Petchartee, Somrak A1 - Monkman, Gareth J. T1 - Pre-slip Sensing through Tactile Sensing T2 - Proc. 2nd International Conference on Sensing Technology (ICST 2007), New Zealand Y1 - 2007 SP - 62 EP - 67 ER - TY - CHAP A1 - Petchartee, Somrak A1 - Monkman, Gareth J. T1 - Pre-slip detection based Tactile Sensing T2 - Proc. 3rd International Conference on Intelligent Sensors, Sensor Networks and Information Processing (ISSNIP 2007), Melbourne Y1 - 2007 SP - 233 EP - 238 ER - TY - CHAP A1 - Petchartee, Somrak A1 - Monkman, Gareth J. T1 - Contact Recognition using Tactile Sensor T2 - Proc. International Symposium on System Theory, Automation, Robotics, Computers, Informatics, Electronics and Instrumentation (SINTES13), Romania Y1 - 2007 SP - 285 EP - 290 ER - TY - JOUR A1 - Petchartee, Somrak A1 - Monkman, Gareth J. T1 - Contact Recognition using Tactile Sensor JF - Annals Universitaria Craiova-Series: Automation, Computers, Electronics and Mechatronics N2 - The surface recognition algorithm that determines the types of contact surfacesby fusing information collected by the tactile sensor system is proposed. The tactilesystem will be determined from the shape of the object image which can then becharacterized using the mathematical properties of Quadric surface. This algorithm canrecognize 3-D objects using a 2-fingered robot gripper, on which tactile sensors aremounted. Experiments have demonstrated the reliability of the surface classificationmethod and the accuracy of transformations independent of an object’s shape, translationand rotation. Y1 - 2007 UR - https://www.academia.edu/1204885/CONTACT_RECOGNITION_USING_TACTILE_SENSOR VL - 4 (31) IS - 2 SP - 103 EP - 108 ER - TY - JOUR A1 - Petchartee, Somrak A1 - Monkman, Gareth J. T1 - Pre-slip Sensing through Tactile Sensing JF - Sensors & Transducers Y1 - 2008 UR - https://www.sensorsportal.com/HTML/DIGEST/P_SI_48.htm SN - 1726-5479 VL - 90 IS - 4, Special Issue SP - 310 EP - 324 PB - International Frequency Sensor Association (IFSA) ER - TY - CHAP A1 - Mayer, Matthias A1 - Monkman, Gareth J. T1 - Modern permanent magnetic materials: Advances and limits T2 - Inductica - Berlin Messe, 22-24 May 2007 Y1 - 2007 ER - TY - CHAP A1 - Dötsch, Horst A1 - Holthaus, Carsten A1 - Trifonov, A. A1 - Klank, Michael A1 - Hagedorn, Oliver A1 - Shamonin (Chamonine), Mikhail A1 - Schützmann, J. T1 - Application of Magnetic Garnet Films for Magnetooptical Imaging of Magnetic Field Distributions T2 - MRS Online Proceedings Library N2 - 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. Y1 - 2004 U6 - https://doi.org/10.1557/PROC-834-J6.1 SP - 18 EP - 29 PB - Springer ER - TY - JOUR A1 - Apelsmeier, Andreas A1 - Schmauss, Bernhard A1 - Shamonin (Chamonine), Mikhail T1 - Compensation of parasitic losses in an extrinsic fiber-optic temperature sensor based on intensity measurement JF - Sensors and Actuators A: Physical N2 - A method of referencing in an extrinsic optical fiber sensor system utilizing temperature dependence of the absorption edge in a semiconductor crystal (semi-insulating iron-doped indium phosphide) is demonstrated. The intensity reference is provided by controlling the temperature of an LED source and transmission measurements with different emission spectra. A transient operation regime is introduced. The entire process is controlled by a microprocessor unit. The performance of the sensor system is investigated and it is shown that the connector losses may be compensated for. Contrary to the published works performed with GaAs crystals it was not observed that the absorption coefficient of the semiconductor follows the law for idealized direct-gap semiconductor but can be described by the so-called Urbach tail. Since the proposed sensor system comprises a single LED source, simple electronics and no optical fiber couplers it is promising for realization of low-cost fiber-optic temperature sensors, e.g. for power transformer monitoring or magnetic resonance imaging applications. KW - Extrinsic optical fiber sensor KW - Temperature measurement KW - Intensity measurement KW - Intensity referencing KW - Indium phosphide KW - Transient operation Y1 - 2012 U6 - https://doi.org/10.1016/j.sna.2011.10.015 VL - 173 IS - 1 SP - 49 EP - 54 ER - TY - JOUR A1 - Apelsmeier, Andreas A1 - Gleixner, Ramona A1 - Mayer, Matthias A1 - Shamonin (Chamonine), Mikhail A1 - Schmauss, Bernhard T1 - Intensity referencing in an extrinsic optical fiber temperature sensor JF - Procedia Engineering N2 - Optical fiber sensors based on intensity measurement require some form of intensity referencing to avoid errors arising from parasitic losses. Known techniques of referencing such as balanced bridge, divided beam systems or two-wavelength referencing are not suitable for low-cost applications since they use relatively complicated optical components such as multiple LED sources, couplers, filters etc. In this work a novel method of referencing in an extrinsic optical fiber sensor system utilizing temperature dependence of absorption edge in a semiconductor crystal is described. The sensor system comprises a single LED source and no optical fiber junctions. The emission spectrum of an LED depends on its temperature. The reference is provided by controlling the temperature of an LED source and transmission measurements with different emission spectra. The entire process is controlled by a microprocessor unit. Performance of a sensor system is investigated and it is shown that the losses in connectors may be compensated for. KW - Extrinsic optical fiber sensor KW - Intensity referencing KW - Temperature measurement KW - Absorption edge KW - Semiconductor KW - Hot-spot measurement Y1 - 2010 U6 - https://doi.org/10.1016/j.proeng.2010.09.301 VL - 5 SP - 1095 EP - 1098 PB - Elsevier 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 - JOUR A1 - Fuxen, Philipp A1 - Schönhärl, Stefan A1 - Schmidt, Jonas A1 - Gerstner, Mathias A1 - Jahn, Sabrina A1 - Graf, Julian A1 - Hackenberg, Rudolf A1 - Mottok, Jürgen T1 - A Cybersecurity Education Platform for Automotive Penetration Testing JF - International Journal On Advances in Security N2 - The paper presents a penetration testing framework for automotive IT security education and evaluates its realization. The automotive sector is changing due to automated driving functions, connected vehicles, and electric vehicles. This development also creates new and more critical vulnerabilities. This paper addresses a possible countermeasure, automotive IT security education. Some existing solutions are evaluated and compared with the created Automotive Penetration Testing Education Platform (APTEP) framework. In addition, the APTEP architecture is described. It consists of three layers representing different attack points of a vehicle. The realization of the APTEP is a hardware case and a virtual platform referred to as the Automotive Network Security Case (ANSKo). The hardware case contains emulated control units and different communication protocols. The virtual platform uses Docker containers to provide a similar experience over the internet. Both offer two kinds of challenges. The first introduces users to a specific interface, while the second combines multiple interfaces, to a complex and realistic challenge. This concept is based on modern didactic theories, such as constructivism and problem-based/challenge-based learning. Computer Science students from the Ostbayerische Technische Hochschule (OTH) Regensburg experienced the challenges as part of a elective subject. In an online survey evaluated in this paper, they gave positive feedback. Also, a part of the evaluation is the mapping of the ANSKo and the maturity levels in the Software Assurance Maturity Model (SAMM) practice Education & Guidance as well as the SAMM practice Security Testing. The scientific contribution of this paper is to present an APTEP, a corresponding learning concept and an evaluation method. KW - Challenge-based Learning KW - Education Framework KW - Penetration Testing KW - Automotive KW - IT-Security Education Y1 - 2022 UR - http://www.iariajournals.org/security/sec_v15_n34_2022_paged.pdf SN - 1942-2636 VL - 15 IS - 3&4 SP - 106 EP - 118 PB - IARIA ER - TY - JOUR A1 - Li, Liwen A1 - Lange, Klaus W. T1 - Planning Principles for Integrating Community Empowerment into Zero-Net Carbon Transformation JF - smart cities N2 - 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. T2 - Planungsprinzipien für die Integration von Community Empowerment in die Zero-Net Carbon Transformation KW - social science KW - environmental planning KW - responsible research innovation KW - public–private partnerships KW - low-carbon communities KW - participatory action research KW - collective actions Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-57765 VL - 2023 IS - 6 SP - 100 EP - 122 PB - MDPI CY - Basel ER - TY - JOUR A1 - Klank, Michael A1 - Hagedorn, Oliver A1 - Holthaus, Carsten A1 - Shamonin (Chamonine), Mikhail A1 - Dötsch, Horst T1 - Characterization and optimization of magnetic garnet films for magneto-optical visualization of magnetic field distributions JF - NDT & E International N2 - 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. KW - Magneto-optics KW - Imaging KW - Magnetic flux leakage KW - Garnet films Y1 - 2003 U6 - https://doi.org/10.1016/S0963-8695(03)00012-4 VL - 36 IS - 6 SP - 375 EP - 381 PB - Elsevier 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 - 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 -