TY - CHAP A1 - Nadimpalli, Vamsi Krishna A1 - Maier, Robert A1 - Staufer, Susanne A1 - Röhrl, Simon A1 - Ezer, Timur A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - EXPERT SURVEYS TO REAL TIME ADAPTATION OF LEARNING PATHS T2 - ICERI2025 Proceedings N2 - Learning management systems rely on adaptive algorithms that use learner preferences to personalize the instructional content in form of learning paths. However, these preferences are uncertain in nature, and change over time. The present solutions are either static or purely data-driven missing the dynamic adaption to changes in the preferences and infusion of pedagogical nuances respectively. This paper introduces an extended variant of Nestor, our Bayesian network engine that models personality traits, learning styles, and learning strategies. This extension overlays a lightweight rule-based mechanism whose “secret recipe’’ lies in the infusion of expert-derived weights adapting learning paths dynamically whenever a learner selects new material in Moodle. To parameterise these rules, we conducted a structured survey with 12 hand-picked professors and researchers in educational science. Each expert responded to 4 demographic items and 12 item that are distributed across algorithm-overview, scenario-based, and example-based categories, thereby supplying the nuanced weightings that result the personalised recommendations. This hybrid system (Nestor plus the expert-infused rule layer) operated during the winter term of 2025. 18 students completed an end-of-term questionnaire. Although their learning gains were not recorded, the majority of respondents reported positive or neutral experiences with the dynamically adapted learning paths. The {Future work} will compare three engines: (i) the present dynamic, expert-infused rule layer on top of the static Bayesian network, (ii) purely data-driven machine-learning models that neglect expert weighting, and (iii) the original static-adaptation Bayesian network without rules. Analyses of log files, intermediate satisfaction surveys, and pre/post term surveys will clarify whether this on-the-fly adaptation and pedagogical nuance lead to measurable learning benefits. Y1 - 2025 U6 - https://doi.org/10.21125/iceri.2025.1571 SP - 5677 EP - 5687 PB - IATED ER - TY - CHAP A1 - Schaffer, Josefa A1 - Ezer, Timur A1 - Röhrl, Simon A1 - Hauser, Florian A1 - Staufer, Susanne A1 - Nadimpalli, Vamsi Krishna A1 - Grabinger, Lisa A1 - Antoni, Erika A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - EYE TRACKING GLASSES IN EDUCATIONAL SETTINGS: GUIDELINES ON DATA QUALITY T2 - ICERI2025 Proceedings N2 - Eye movement modeling examples, so-called EMME videos, are a valuable tool in education, helping learners better understand instructional content. Like conventional educational videos, EMME videos combine text, images, and voiceovers. However, they also display the instructor’s or teacher’s gaze, guiding learners attention to key elements. Although various approaches exist for creating EMME videos, there is currently no standardised guideline for ensuring gaze data quality. Eye tracking technology is essential to capture gaze behaviour, and in educational settings without a fixed computer monitor – such as when using blackboards or conducting live experiments – the usage of mobile eye tracking glasses is beneficial. An accuracy study is conducted using mobile eye tracking glasses to provide empirical guidance for the development of high-quality educational EMME videos and ensure that the instructor’s or teacher’s gaze is captured with high precision. The study uses the Tobii Pro Glasses 3 and involves a static and a dynamic setup with 34 participants. To gain insight into the effects of visual impairments on accuracy, we also include participants who wear contact lenses. In the static setup, participants are seated at a desk with a headrest and focus on a poster with nine fixation points. In the dynamic setup, participants are walking in a controlled half-circle around the poster while maintaining focus on its centre. Each setup is performed multiple times under varying lighting levels (300 lux, 700 lux) and distances between participant and poster (80 cm, 120 cm, 180 cm). This enables the simulation of diverse educational environments, including the possibility of a teacher’s or instructor’s movement. The study results will be evaluated regarding lighting conditions, the distance between the person wearing eye tracking glasses and the object, and possible influences of contact lenses. Based on these findings, favourable conditions for creating EMME videos in educational settings are collected, especially when working without a fixed computer monitor. The results address the outlined research gap by providing instructors and teachers with guidelines enabling them to produce high-quality educational EMME videos. Y1 - 2025 U6 - https://doi.org/10.21125/iceri.2025.1419 SP - 5027 EP - 5038 PB - IATED ER - TY - CHAP A1 - Alhulaibi, Ayham A1 - Frauenschläger, Tobias A1 - Mottok, Jürgen T1 - Towards Post-Quantum-Ready Automated Certificate Lifecycle Management in Operational Technology T2 - SECURWARE 2025, The Nineteenth International Conference on Emerging Security Information, Systems and Technologies, 26.-30.10.2025, Barcelona N2 - Operational Technology (OT) systems increasingly depend on robust and automated certificate lifecycle management to maintain secure operations across long device lifespans and constrained environments. As quantum-capable adversaries emerge, these systems must also support cryptographic agility and prepare for a seamless transition to Post-Quantum Cryptography (PQC). This work presents a crypto-agile, post-quantum-ready testbed architecture that extends existing standards, such as Enrollment over Secure Transport (EST) and Bootstrapping Remote Secure Key Infrastructure (BRSKI), to support hybrid certificates, hardware-based key storage, and protocol flexibility for device bootstrapping and certificate management. A work-in-progress prototype implementation demonstrates support for both traditional and PQC algorithms across device types. Planned evaluations target performance on constrained devices, PQC readiness, and compatibility with alternative protocols. The system lays a foundation for secure and standards-compliant certificate management in future-proof OT deployments. KW - Automated Device Onboarding KW - BRSKI KW - Operational Technology Security. KW - Post-Quantum Cryptography KW - Public Key Infrastructure KW - Security Token Y1 - 2025 UR - https://www.thinkmind.org/library/SECURWARE/SECURWARE_2025 SN - 978-1-68558-306-4 SP - 112 EP - 116 PB - IARIA ER - TY - CHAP A1 - Hauser, Florian A1 - Staufer, Susanne A1 - Röhrl, Simon A1 - Nadimpalli, Vamsi Krishna A1 - Ezer, Timur A1 - Grabinger, Lisa A1 - Mottok, Jürgen A1 - Falter, Thomas ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - LEVERAGING FIVE QUESTIONNAIRES TO ANALYZE STUDENT LEARNING STRATEGIES AND GENERATE AI-POWERED INDIVIDUALIZED LEARNING PATHS T2 - ICERI2025 Proceedings N2 - Background: The COVID-19 pandemic has significantly accelerated the shift toward online and blended learning in higher education, placing renewed emphasis on the individualization of learning content to meet diverse student needs. Even high-quality learning materials may fail to engage learners if they do not align with students’ personal preferences and learning styles. Identifying these learner preferences, therefore, emerges as a critical challenge. Objectives: This paper presents ongoing work within a larger research project aimed at employing artificial intelligence to recommend optimal learning path for students in specific courses. Beyond mere optimization, the goal is to ensure the best possible fit between learning materials and individual learners. Sample & Methods: A total of 27 students from technical degree programs took part in this survey. All participation was voluntary, and data were handled in full compliance with GDPR regulations. Although our broader project integrates fine-grained learning analytics from Moodle, the present abstract focuses exclusively on the self-report questionnaire results. Participants completed five instruments: 1. Index of Learning Styles (ILS) 2. LIST-K (Learning and Study Strategies Inventory – Short version) 3. BFI-10 (Big Five Inventory – 10 items) 4. Custom Preferences Instrument, capturing preferences for specific learning elements (e.g. instructional videos, lecture notes, summaries) and basic demographic data 5. Motivational Value Systems Questionnaire (MVSQ), piloted last semester to assess value orientations and motivational drivers Results: Preliminary analyses of the questionnaire data reveal: - Learning Styles (ILS): The majority lean toward the visual learning type (M = 5.740, SD = 3.430). - Learning Strategies (LIST-K): High scores on metacognitive strategies (M = 3.000; SD = 0.520) and collaboration with peers (M = 3.190; SD = 0.540). - Preferred Learning Elements: Summaries, overviews, and self-checks are most favored. - Value Orientations (MVSQ): Students are primarily driven by the pursuit of personal achievement (M = 4.400; SD = 11.140). Conclusion & Significance: By integrating these five standardized questionnaires, we gain valuable insights into student learning preferences—insights that complement our Moodle analytics in the broader project. Observed trends suggest that learning materials should be concise and designed to facilitate peer interaction and knowledge deepening. These findings will guide the refinement of our AI-driven recommendation engine, enhancing its ability to deliver personalized learning paths that boost both engagement and effectiveness. KW - AI in higher education KW - learning management system KW - adaptive learning KW - personalized learning paths KW - online and blended learning Y1 - 2025 U6 - https://doi.org/10.21125/iceri.2025.0658 SP - 1775 EP - 1784 PB - IATED ER - TY - CHAP A1 - Ezer, Timur A1 - Röhrl, Simon A1 - Mottok, Jürgen ED - Gómez Chova, Luis ED - González Martínez, Chelo ED - Lees, Joanna T1 - Towards accurate eye tracking: quantifying error in linear pixel-to-degree conversion T2 - ICERI2025 Proceedings N2 - Eye tracking has become a powerful tool for analyzing cognitive processes in educational research. Educators and researchers can utilize eye tracking to model learners by determining their gaze patterns. In addition, eye tracking can be used directly for teaching by extracting experts' gaze behavior in certain areas and learning from it. However, eye tracking data is captured in a variety of coordinate systems, which can differ across individual studies. Consequently, algorithms, such as eye movement classifiers, must frequently convert gaze data between different coordinate systems. In particular, the conversion from screen pixels into visual degrees is typically approximated by a linear conversion in current literature and standard practice. However, this approximation introduces inaccuracies, thus potentially obscuring eye movements relevant to educational research. This paper provides a detailed geometric and analytical examination of the commonly applied linear approximation, quantifying its error in comparison to the exact coordinate conversion from screen pixels to angular degrees. For this purpose, the exact conversion formulas are mathematically derived from geometric optics, enabling researchers and educators to use them in their work. Utilizing these derived transformations can improve the robustness of analyses, for example, when detecting subtle eye movements. The present work supports educational research using eye tracking to achieve more insightful findings that may have previously been obscured by measurement inaccuracies. Thereby, we provide an important contribution toward more reliable and valid research and educational practices in eye tracking. KW - Eye tracking KW - coordinate system KW - conversion KW - angular degree KW - pixel Y1 - 2025 U6 - https://doi.org/10.21125/iceri.2025.1841 SP - 6709 EP - 6717 PB - IATED ER - TY - CHAP A1 - Staufer, Susanne A1 - Ezer, Timur A1 - Röhrl, Simon A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Nadimpalli, Vamsi Krishna A1 - Antoni, Erika A1 - Mottok, Jürgen A1 - Schaffer, Josefa T1 - TYCHE ALGORITHM 2.0: Learning Paths from Questionnaire Responses and Learning Analytics T2 - ICERI2025 Proceedings N2 - The digitalization of learning processes has increased the need for adaptive learning paths tailored individually to learners. A novel algorithm for learning path generation is presented in this paper, namely Tyche 2.0. It extends the original Tyche approach after Staufer et al. – a Markov model for generating learning paths – by integrating additional learner data beyond learning styles (Index of Learning Styles (ILS)), including learning strategies (LIST-K questionnaire), personality traits (BFI-10 questionnaire), and learning analytics captured through screen recordings. In order to be able to use the screen recordings, a heuristic evaluates them. Furthermore, this enhanced algorithm employs Markov models to dynamically generate personalized learning paths. These are based on both questionnaire responses and real-time engagement data, the weights of which undergo dynamic adjustment over time. We made a small evaluation of Tyche 2.0 without the learning analytics influence, which shows that there is room for further improvements. Future research will focus on evaluating whole Tyche 2.0 in another university setting to further improve personalization and user engagement. KW - Markov model KW - Learning paths KW - Learning style KW - Learning strategy KW - Personality traits KW - Learning analytics Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-87846 SN - 978-84-09-78706-7 SP - 2562 EP - 2572 PB - IATED ER - TY - CHAP A1 - Hammer, Pascal A1 - Mottok, Jürgen T1 - Prototyping for high-performance random number generators for critical systems T2 - 2025 International Conference on Applied Electronics (AE), 08-09. September 2025, Pilsen Czech Republic N2 - The security of modern cryptographic applications depends on the quality of their random number generators (RNGs). While physical true random number generators (PTRNGs) provide high-quality randomness, their performance is often insufficient for high-throughput applications. On the other hand, deterministic random number generators (DRNGs) offer better speed but lack true randomness. This paper presents an approach to developing a high-performance PTRNG. The research focuses on optimizing the digitization of analog noise signals. For this purpose, an ADC was selected that can digitize analog signals at a high clock rate. The functionality of the ADC could be verified by digitizing reference signals. Preliminary results by digitizing the analog noise signal demonstrates the feasibility of the proposed approach, but highlight challenges in achieving good results for Min-Entropy. Y1 - 2025 U6 - https://doi.org/10.1109/AE66163.2025.11197780 PB - IEEE ER - TY - JOUR A1 - Röhrl, Simon A1 - Staufer, Susanne A1 - Bugert, Flemming A1 - Nadimpalli, Vamsi Krishna A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Bittner, Dominik A1 - Ezer, Timur A1 - Altweck, Ricardo A1 - Graf, Sabine A1 - Kriza, Thomas A1 - Mottok, Jürgen T1 - Ethical Considerations of AI in Education: A Case Study based on Pythia Learning Enhancement System JF - IEEE Access N2 - As the use of AI in education increases, addressing ethical concerns is essential for its responsible use and implementation. This study explores the ethical considerations of AI in education by analyzing a concrete application, the Pythia Learning Enhancement System, which enables personalized and adaptive educational experiences. In this case study, the concrete implementation of Pythia, contrary to high-level abstract analyses, provides practical insights into these ethical issues. To achieve this goal, we first define Pythia and outline its implementation. Using the various topics covered by Pythia, the ethical issues associated with each of these topics are outlined, resulting in a list of ten distinct ethical issues. Because there is overlap in issues covered by similar applications, they can benefit from this identification. An ethical (human rights) and didactic (constructivism) theoretical background is then provided as a basis for further discussion. This is used to build the arguments used in the main study. This consists of analyzing each of the issues and providing recommendations to mitigate potential harm arising from these issues. This helps to provide guidelines for future applications. In the analysis, the ethical discussion is mainly based on the human rights of the stakeholders involved, emphasizing human dignity. After the analysis, each of the issues is contextualized with the recent AI Act of the European Union, providing a novel mapping of the issues of AI in education to the AI Act. Finally, the limitations of the study are stated and a plan for future research is presented. KW - Ethics KW - Artificial intelligence KW - Education KW - Stakeholders KW - Psychology KW - Privacy KW - Search problems KW - Guidelines KW - Focusing KW - Europe Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-83403 SN - 2169-3536 N1 - Corresponding author der OTH Regensburg: Simon Röhrl VL - 11 SP - 1 EP - 25 PB - Institute of Electrical and Electronics Engineers (IEEE) ER - TY - CHAP A1 - Nadimpalli, Vamsi Krishna A1 - Bugert, Flemming A1 - Bittner, Dominik A1 - Staufer, Susanne A1 - Röhrl, Simon A1 - Hauser, Florian A1 - Ezer, Timur A1 - Grabinger, Lisa A1 - Maier, Robert A1 - Mottok, Jürgen T1 - Probabilistic Machine Learning for Simulating Complex Learner Profiles T2 - 2024 21st International Conference on Information Technology Based Higher Education and Training (ITHET), 06-08 November 2024, Paris, France N2 - Data is the foundation of all machine learning applications. In education science, especially for the learner characteristics that drive personalized learning, it is difficult to collect and often uncertain. It is challenging to model, train, evaluate, and analyze the underlying algorithms when developing AI-based systems and having small sample sizes. To address these problems, we present a synthetic data generator utilising probabilistic models. This generator can effectively model and simulate complex learner profiles. To achieve this, we collected extensive data on learning styles, learning strategies, personalities, and preferred learning paths from 593 students over several semesters at a higher education level. Then, Bayesian networks, Hidden Markov Models, and Markov Chains are used to model the relationships between learner profiles. Using the Bayesian information criterion, and cross-validation with log-likelihood scores, we compare various models to select the best fitting one for synthesizing the data. The synthetic data is then evaluated using statistical validation techniques. In addition, we developed a simulation module with the option to simulate learner profiles based on manual user-defined inputs. The data and code used in this work are available as open source1110.5281/zenodo.13768136 [Titel anhand dieser DOI in Citavi-Projekt übernehmen] contributing to open science and developers for customized simulated data. In the future, this data will refine the training, evaluation, analysis, and benchmarking of algorithms for personalized learning. KW - probabilistic models KW - synthetic data KW - learner characteristics KW - generative AI KW - higher education area Y1 - 2024 SN - 979-8-3315-1663-5 U6 - https://doi.org/10.1109/ITHET61869.2024.10837641 SN - 2473-2060 SP - 1 EP - 10 PB - IEEE ER - TY - CHAP A1 - Bugert, Flemming A1 - Staufer, Susanne A1 - Bittner, Dominik A1 - Nadimpalli, Vamsi Krishna A1 - Ezer, Timur A1 - Hauser, Florian A1 - Grabinger, Lisa A1 - Mottok, Jürgen T1 - Ariadne's Thread for Unravelling Learning Paths: Identifying Learning Styles via Hidden Markov Models T2 - 2024 IEEE Global Engineering Education Conference (EDUCON), 08-11 May 2024, Kos Island, Greece N2 - Modern education through Learning Management Systems (LMSs) provides learners with personalized learning paths. This is achieved by first querying the learning style according to the theory of Felder and Silverman to recommend suitable learning content. However, a rigid learning style representation is lacking of adaptability to the learners' choices. Therefore, the present study evaluates the idea of providing adaption to the representation of learning styles by using Hidden Markov Models (HMMs). Thus, data is collected from participants out of the Higher Education Area. The Index of Learning Styles questionnaire is used to obtain the learning style based on the theory of Felder and Silverman. Also, a questionnaire that asks the respondents to create a preferred learning path with the sequence length of nine learning elements is provided. From the given data, we initially evaluate the probability relationships between learning styles and learning elements. Then, we use the Viterbi algorithm in HMMs to identify alterations in learning styles from the provided learning paths. The alignment is then quantified by introducing a metric called support value. The findings imply that our concept can be used to adapt the learning style based on the user's real choice of learning elements. Thus, the proposed model also offers a way to integrate a feedback loop within LMSs leading to an improvement of learning path recommendation algorithms. KW - Surveys KW - Knowledge engineering KW - Feedback loop KW - Learning management systems KW - Uncertainty KW - Viterbi algorithm Y1 - 2024 U6 - https://doi.org/10.1109/EDUCON60312.2024.10578825 SN - 2165-9567 SP - 1 EP - 7 PB - IEEE ER - TY - 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 - 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 - 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 - 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 - 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 - 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 - 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 - Joseph, Saskia A1 - Schumm, Michael A1 - Rummel, Otmar A1 - Soska, Alexander A1 - Renschke, Michael A1 - Mottok, Jürgen A1 - Niemetz, Michael A1 - Schroll-Decker, Irmgard T1 - Teaching finite state machines with case method and role play JF - 2014 IEEE Global Engineering Education Conference (EDUCON 2014) : Istanbul, Turkey, 3 - 5 April 2014 N2 - The professional requirements in Software Engineering have become highly volatile due to the complexities of project development and rapid and innovative changes occurring in the field. Therefore, the development of inter-personal and social competences has gained central importance in the training of software developers. This paper will present a concept allowing to acquire competences by using Case Method and Role Play as instruments in several lectures of Software Engineering. By approaching the issue of competence acquisition on a technical as well as on an educational and social level, life-long learning is facilitated and supported. KW - Case Method KW - competences KW - learning arrangement KW - life-long learning KW - Role Play Y1 - 2013 U6 - https://doi.org/10.1109/EduCon.2013.6530275 SP - 1302 EP - 1305 PB - IEEE ER - TY - CHAP A1 - Maier, Robert A1 - Grabinger, Lisa A1 - Urlhart, David A1 - Mottok, Jürgen ED - Seguin, Christel ED - Zeller, Marc ED - Prosvirnova, Tatiana T1 - Towards Causal Model-Based Engineering in Automotive System Safety T2 - Model-Based Safety and Assessment, 8th International Symposium, IMBSA 2022: Munich, Germany, September 5–7, 2022, Proceedings N2 - Engineering is based on the understanding of causes and effects. Thus, causality should also guide the safety assessment of complex systems such as autonomous driving cars. To ensure the safety of the intended functionality of these systems, normative regulations like ISO 21448 recommend scenario-based testing. An important task here is to identify critical scenarios, so-called edge and corner cases. Data-driven approaches to this task (e.g. based on machine learning) cannot adequately address a constantly changing operational design domain. Model-based approaches offer a remedy – they allow including different sources of knowledge (e.g. data, human experts) into safety considerations. With this paper, we outline a novel approach for ensuring automotive system safety. We propose to use structural causal models as a probabilistic modelling language to combine knowledge about an open-context environment from different sources. Based on these models, we investigate parameter configurations that are candidates for critical scenarios. In this paper, we first discuss some aspects of scenario-based testing. We then provide an informal introduction to causal models and relate their development lifecycle to the established V-model. Finally, we outline a generic workflow for using causal models to identify critical scenarios and highlight some challenges that arise in the process. Y1 - 2022 U6 - https://doi.org/10.1007/978-3-031-15842-1_9 SP - 116 EP - 129 PB - Springer Nature CY - Cham ER - TY - CHAP A1 - Maier, Robert A1 - Mottok, Jürgen ED - Trapp, Mario ED - Saglietti, Francesca ED - Spisländer, Marc ED - Bitsch, Friedemann T1 - BayesianSafety - an Open-Source Package for Causality-Guided, Multi-Model Safety Analysis T2 - Computer Safety, Reliability, and Security, 41st International Conference (SAFECOMP 2022): Munich, Germany, September 6–9, 2022, Proceedings T2 - Lecture notes in computer science ; 13414 N2 - Development and verification of modern, dependable automotive systems require appropriate modelling approaches. Classic automotive safety is described by the normative regulations ISO 26262, its relative ISO/PAS 21448, and their respective methodologies. In recent publications, an emerging demand to combine environmental influences, machine learning, or reasoning under uncertainty with standard-compliant analysis techniques can be noticed. Therefore, adapting established methods like FTA and proper tool support is necessary. We argue that Bayesian Networks (BNs) can be used as a central component to address and merge these demands. In this paper, we present our Open-Source Python package BayesianSafety. First, we review how BNs relate to data-driven methods, model-to-model transformations, and causal reasoning. Together with FTA and ETA, these models form the core functionality of our software. After describing currently implemented features and possibilities of combining individual modelling approaches, we provide an informal view of the tool’s architecture and of the resulting software ecosystem. By comparing selected publicly available safety and reliability analysis libraries, we outline that many relevant methodologies yield specialized implementations. Finally, we show that there is a demand for a flexible, unifying analysis tool that allows researching system safety by using multi-model and multi-domain approaches. KW - Package BayesianSafety KW - Causality KW - Bayesian Networks KW - Event Tree Analysis KW - Fault Tree Analysis Y1 - 2022 U6 - https://doi.org/10.1007/978-3-031-14835-4_2 SP - 17 EP - 30 PB - Springer Nature CY - Cham ER - TY - CHAP A1 - Maier, Robert A1 - Mottok, Jürgen T1 - Causality and Functional Safety - How Causal Models Relate to the Automotive Standards ISO 26262, ISO/PAS 21448, and UL 4600 T2 - 27th International Conference on Applied Electronics (AE): 06-07 September 2022, Pilsen, CZ N2 - With autonomous driving, the system complexity of vehicles will increase drastically. This requires new approaches to ensure system safety. Looking at standards like ISO 26262 or ISO/PAS 21448 and their suggested methodologies, an increasing trend in the recent literature can be noticed to incorporate uncertainty. Often this is done by using Bayesian Networks as a framework to enable probabilistic reasoning. These models can also be used to represent causal relationships. Many publications claim to model cause-effect relations, yet rarely give a formal introduction of the implications and resulting possibilities such an approach may have. This paper aims to link the domains of causal reasoning and automotive system safety by investigating relations between causal models and approaches like FMEA, FTA, or GSN. First, the famous “Ladder of Causation” and its implications on causality are reviewed. Next, we give an informal overview of common hazard and reliability analysis techniques and associate them with probabilistic models. Finally, we analyse a mixed-model methodology called Hybrid Causal Logic, extend its idea, and build the concept of a causal shell model of automotive system safety. KW - Causality KW - Reliability KW - Functional Safety Y1 - 2022 U6 - https://doi.org/10.1109/AE54730.2022.9920053 PB - IEEE ER - TY - CHAP A1 - Frauenschläger, Tobias A1 - Mottok, Jürgen T1 - Security-Gateway for SCADA-Systems in Critical Infrastructures T2 - 27th International Conference on Applied Electronics (AE): 06-07 September 2022, Pilsen, CZ N2 - Supervisory Control and Data Acquisition (SCADA) systems are used to control and monitor components within the energy grid, playing a significant role in the stability of the system. As a part of critical infrastructures, components in these systems have to fulfill a variety of different requirements regarding their dependability and must also undergo strict audit procedures in order to comply with all relevant standards. This results in a slow adoption of new functionalities. Due to the emerged threat of cyberattacks against critical infrastructures, extensive security measures are needed within these systems to protect them from adversaries and ensure a stable operation. In this work, a solution is proposed to integrate extensive security measures into current systems. By deploying additional security-gateways into the communication path between two nodes, security features can be integrated transparently for the existing components. The developed security-gateway is compliant to all regulatory requirements and features an internal architecture based on the separation-of-concerns principle to increase its security and longevity. The viability of the proposed solution has been verified in different scenarios, consisting of realistic field tests, security penetration tests and various performance evaluations. KW - Critical Infrastructure KW - Certification KW - Supervisory Control and Data Acquisition KW - Security KW - Dependability Y1 - 2022 U6 - https://doi.org/10.1109/AE54730.2022.9920070 PB - IEEE ER - TY - CHAP A1 - Jahn, Sabrina A1 - Kaul, Nicolas A1 - Mottok, Jürgen T1 - Using or Misusing? Introducing Misuse Cases in a Software Engineering Course for Undergraduate Engineering Students T2 - ITiCSE '22 : Proceedings of the 27th ACM Conference on on Innovation and Technology in Computer Science Education, Vol 1: July 8 - 13, 2022, Dublin Ireland N2 - Today's cyberphysical systems are increasingly prone to misuse. To secure existing and future software systems, introducing concepts of IT-Security and Secure Software Engineering (SecSE) in Software Engineering (SE) courses is essential for academic education of future software engineers. This is not only important for computer science students, but also for engineering students studying topics of computing and SE. However, only little research exists on integrating these topics into traditional SE courses, especially for engineering students in non-computer science majors. To narrow this gap, this paper contributes with the design and evaluation of an exercise on modeling misuse cases alongside use cases, based on the inductive teaching method problem-based learning (PBL). The exercise is part of an educational design research investigating which learning content and teaching methods are suitable for integrating IT-Security and SecSE topics into traditional SE education of engineering students to convey factual knowledge as well as raise awareness and interest for both topics during software development. We present the integration of the exercise design into a traditional SE course for engineering students and its evaluation to examine its suitability. We evaluated the exercise design regarding the suitability of the design components, the learning content of misuse cases and the intended learning goals as well as its impact on students' motivation, and their interest in IT-security. The paper then presents indications on the feasibility and success of the exercise design for teaching misuse cases to engineering students and sparking their interest in IT-Security. KW - educational design research KW - mis-use case KW - problem-based learning KW - inductive teaching KW - engineering students KW - higher education KW - secure software engineering KW - IT-Security Y1 - 2022 U6 - https://doi.org/10.1145/3502718.3524823 SP - 491 EP - 497 PB - Association for Computing Machinery CY - New York, NY ER - TY - CHAP A1 - Grabinger, Lisa A1 - Hauser, Florian A1 - Mottok, Jürgen T1 - Accessing the Presentation of Causal Graphs and an Application of Gestalt Principles with Eye Tracking T2 - 2022 IEEE International Conference on Software Analysis, Evolution and Reengineering (SANER 2022), 1st Workshop on Advances in Human-Centric Experiments in Software Engineering (HUMAN 2022): 15-18 March 2022, Honolulu, HI, USA N2 - The discipline of causal inference uses so-called causal graphs to model cause and effect relations of random variables. As those graphs only encode a relation structure there is no hard rule concerning their alignment. The present paper presents a study with the aim of working out the optimal alignment of causal graphs with respect to comprehensibility and interestingness. In addition, the study examines whether the central gestalt principles of psychology apply for causal graphs. Data from 29 participants is acquired by triangulating eye tracking with a questionnaire. The results of the study suggest that causal graphs should be aligned downwards. Moreover, the gestalt principles proximity, similarity and closure are shown to hold true for causal graphs. KW - causal graphs KW - gestalt principles KW - eye tracking Y1 - 2022 U6 - https://doi.org/10.1109/SANER53432.2022.00153 SP - 1278 EP - 1285 PB - IEEE ER - TY - CHAP A1 - Lalo, Erjola A1 - Sailer, Andreas A1 - Mottok, Jürgen A1 - Siemers, Christian T1 - Overhead-Aware Schedule Synthesis for Logical Execution Time (LET) in Automotive Systems T2 - 2022 IEEE 35th International System-on-Chip Conference (SOCC): 05-08 September 2022, Belfast, United Kingdom N2 - The Logical Execution Time (LET) has recently been integrated in multi-core automotive systems to ensure timing and dataflow determinism. Although buffering mechanisms are introduced to incorporate LET semantics, they do not guarantee that tasks are executed within their LET frames. In fact, LET and buffering semantics are violated if scheduling is not designed to execute all tasks within their LET frames and in a specific order. In this paper, we describe a scheduling synthesis technique for Fixed-Priority Scheduling (FPS) to achieve resource-efficient execution of LET systems. The proposed approach considers LET semantics, scheduling overheads, and delays caused by operating system operations and provides the possibility to optimize the schedule with respect to aspects like scheduling overheads. Our performance and feasibility evaluation shows that the proposed algorithm provides results in a reasonable amount of time for models of complex industrial applications. Thus, the integration of the proposed algorithm into an automated process is of high benefit to accelerate the development of vehicle applications. Y1 - 2022 SN - 978-1-6654-5985-3 U6 - https://doi.org/10.1109/SOCC56010.2022.9908103 SP - 1 EP - 6 PB - IEEE ER - TY - CHAP A1 - Pozzobon, Enrico A1 - Renner, Sebastian A1 - Mottok, Jürgen A1 - Matoušek, Václav T1 - An optimized Bitsliced Masked Adder for ARM Thumb-2 Controllers T2 - 27th International Conference on Applied Electronics (AE): Sep 6, 2022 - Sep 7, 2022, Pilsen, Czech Republic N2 - The modular addition is used as a non-linear operation in ARX ciphers because it achieves the requirement of introducing non-linearity in a cryptographic primitive while only taking one clock cycle to execute on most modern architectures. This makes ARX ciphers especially fast in software implementations, but comes at the cost of making it harder to protect against side-channel information leakages using Boolean masking: the best known 2-shares masked adder for ARM Thumb micro-controllers takes 83 instructions to add two 32-bit numbers together. Our approach is to operate in bitsliced mode, performing 32 additions in parallel on a 32-bit microcontroller. We show that, even after taking into account the cost of bitslicing before and after the encryption, it is possible to achieve a higher throughput on the tested ciphers (CRAX and ChaCha20) when operating in bitsliced mode. Furthermore, we prove that no first-order information leakage is happening in either simulated power traces and power traces acquired from real hardware, after sufficient countermeasures are put into place to guard against pipeline leakages. KW - ARM Thumb KW - bitsliced KW - side-channel KW - Boolean masking Y1 - 2022 U6 - https://doi.org/10.1109/AE54730.2022.9919884 PB - IEEE ER - TY - JOUR A1 - Schmid, Michael A1 - Fritz, Florian A1 - Mottok, Jürgen T1 - Fine-grained parallelism framework with predictable work-stealing for real-time multiprocessor systems JF - Journal of Systems Architecture N2 - Lately, parallel task models have received much attention in the development of real-time multiprocessor systems, as they allow highly compute-intensive tasks to have shorter deadlines which is very much required in modern reactive systems. However, missing modularity and portability can make parallel programming a cumbersome endeavor. As a consequence, compute-intensive sectors in the desktop and server segment have relied on parallelism frameworks such as Intel Threading Building Blocks, Cilk and OpenMP. These parallelism frameworks, however, are optimized for decent average case performance and consequently, do not meet the strict requirements imposed by real-time systems. In this paper, we present a proof-of-concept parallelism framework which was implemented in particular for soft real-time systems and having tight timing and safety requirements of such critical systems in mind. The proposed runtime system implements static memory allocation in a work-stealing environment that conforms to the strict space and tight probabilistic time bounds of work-stealing schedulers. Furthermore, we evaluate the performance of this framework by conducting multiprogrammed benchmarks on a real-time embedded multicore architecture. Y1 - 2022 U6 - https://doi.org/10.1016/j.sysarc.2022.102393 N1 - Corrigendum: https://www.sciencedirect.com/science/article/pii/S1383762123000528?via%3Dihub VL - 124 IS - March PB - Elsevier ER - TY - CHAP A1 - Mucha, Matthias A1 - Mottok, Jürgen A1 - Krämer, Stefan T1 - Estimation of Worst Case Response Time Boundaries in Multi-Core Real-Time Systems T2 - 2017 International Conference on Applied Electronics (AE), 5-6 Sept. 2017, Pilsen N2 - We address a novel probabilistic approach to estimate the Worst Case Response Time boundaries of tasks. Multi-core real-time systems process tasks in parallel on two or more cores. Tasks in our contribution may preempt other tasks, block tasks with semaphores to access global shared resources, or migrate to another core. The depicted task behavior is random. The shape of collected response times of a task within a processing time is multimodal. Extreme Value approaches need unimodal response time distributions to estimate the Worst Case Response Time of tasks. The new proposed method derives a set of three task set shapes from the source task set. It is used to minimize the uncertainty of random task behavior by maximizing the coverage of possible Worst Case Response Times. The case study evaluates the new proposed estimation method by the use of dynamically generated random tasks with varying task properties. Y1 - 2017 SN - 978-80-261-0641-8 U6 - https://doi.org/10.23919/ae.2017.8053598 SN - 1803-7232 SP - 1 EP - 6 PB - IEEE ER - TY - CHAP A1 - Schönhärl, Stefan A1 - Fuxen, Philipp A1 - Graf, Julian A1 - Schmidt, Jonas A1 - Hackenberg, Rudolf A1 - Mottok, Jürgen T1 - An Automotive Penetration Testing Framework for IT-Security Education T2 - Cloud Computing 2022: The Thirteenth International Conference on Cloud Computing, GRIDs, and Virtualization, Special Track FAST-CSP, Barcelona, Spain, 24.-28.04.2022 N2 - Automotive Original Equipment Manufacturer (OEM) and suppliers started shifting their focus towards the security of their connected electronic programmable products recently since cars used to be mainly mechanical products. However, this has changed due to the rising digitalization of vehicles. Security and functional safety have grown together and need to be addressed as a single issue, referred to as automotive security, in the following article. One way to accomplish security is automotive security education. The scientific contribution of this paper is to establish an Automotive Penetration Testing Education Platform (APTEP). It consists of three layers representing different attack points of a vehicle. The layers are the outer, inner, and core layers. Each of those contains multiple interfaces, such as Wireless Local Area Network (WLAN) or electric vehicle charging interfaces in the outer layer, message bus systems in the inner layer, and debug or diagnostic interfaces in the core layer. One implementation of APTEP is in a hardware case and as 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 theory, such as constructivism and problem-based learning. Computer Science students from the Ostbayerische Technische Hochschule (OTH)Regensburg experienced the challenges as part of a special topic course and provided positive feedback. KW - IT-Security KW - Education KW - Automotive KW - Penetration testing KW - Education framework Y1 - 2022 UR - https://www.thinkmind.org/index.php?view=article&articleid=cloud_computing_2022_1_10_28001 SN - 978-1-61208-948-5 SP - 1 EP - 6 PB - IARIA CY - [Wilmington, DE, USA] ER - TY - CHAP A1 - Studt, Reimer A1 - Weiß, Florian A1 - Mottok, Jürgen A1 - Weiss, Florian A1 - Mottok, Jürgen T1 - An engineering approach to developing lecture material for new study courses T2 - 2014 IEEE Global Engineering Education Conference (EDUCON), 3-5 April 2014, Istanbul, Turkey N2 - Professional software development is a complex task with many inputs and a complex output. In order to handle complex topics as software or complex engineering projects, structured processes as the V-model or iterative development processes exist. Similarly, the development of a software engineering lecture is a task with many inputs, and a complex output. A structured and methodological approach to the development of a lecture is presented, which applies the same principles as used in the development of software. KW - biomedical engineering KW - competence model KW - computer science education KW - Education KW - Insulin KW - Knowledge engineering KW - lecture development KW - Materials KW - Software KW - Software engineering KW - Unified modeling language Y1 - 2014 U6 - https://doi.org/10.1109/EDUCON.2014.6826153 SP - 592 EP - 597 PB - IEEE ER - TY - CHAP A1 - Tao, Ye A1 - Liu, Guozhu A1 - Mottok, Jürgen A1 - Hackenberg, Rudolf A1 - Hagel, Georg A1 - Mottok, Jürgen T1 - Just-in-Time Teaching in software engineering: A Chinese-German empirical case study T2 - 2014 IEEE Global Engineering Education Conference (EDUCON), 3-5 April 2014, Istanbul, Turkey N2 - Learning centered teaching becomes an important factor in a global perspective of learning software engineering. The Just-in-Time Teaching approach is used in a Chinese-German empirical case study. In a one year terminated project we will analyze the performance of our students in an active learning scenario with Just-in-Time Teaching and Peer Instruction. We will contribute an inter-cultural comparison of achieved competencies by student’s self-assessment and teacher’s observation. KW - Activating Learning KW - Blended Learning KW - Conferences KW - Educational institutions KW - E-Learning KW - ISO Standards KW - JiTT KW - Just-in-Time Teaching KW - Materials KW - Practical Learning KW - Software KW - Software engineering Y1 - 2014 U6 - https://doi.org/10.1109/EDUCON.2014.6826220 SP - 983 EP - 986 PB - IEEE ER - TY - CHAP A1 - De, Sangita A1 - Mottok, Jürgen A1 - Niklas, Michael A1 - Brada, Premek ED - Trinitis, Carsten ED - Pionteck, Thilo T1 - Semantic Synergy Exploration in Interface Description Models of Heterogeneous Vehicle Frameworks: Towards Automotive Meta Interface Description Model T2 - ARCS 2019: 32nd GI/ITG International Conference on Architecture of Computing Systems May 20 - 21, 2019, Technical University of Denmark, Copenhagen, Denmark Workshop, Proceedings N2 - This The vehicle is evolving to a complex network of heterogeneous subsystems of ECUs, sensors and actuators, each with different computational requirements. These sub-systems are connected via bus systems following different communication paradigms like e.g. signal based or service-oriented communications. This has led to the heterogeneous syntax of describing interfaces even though the semantics of the interfaces are similar. The wide variety of Interface Description Languages (IDLs) in automotive industry hinders partly with the efficient collaboration between different suppliers and the OEMs in the automotive industry. Given this wide variety of automotive IDLs, what could be more beneficial, from a software engineering point of view, is a generic automotive domain specific IDL that can satisfy all the fundamental requirements of the heterogeneous subsystems. This paper describes an approach to compare and correlate IDLs based on semantic similarities of the languages, considering the two aspects: application description and underlying message frameworks used in the different domains of given automotive subsystems. With the exploration of semantic synergies between the IDLs, various domain specific and domain-agnostic frameworks can be compared and correlated. The results can be generalized and abstracted to define a generic Meta IDL which could support use cases like e.g. domain-agnostic functional models and migration of software components between different kinds of automotive subsystems. Y1 - 2019 UR - https://ieeexplore.ieee.org/document/8836199 SN - 978-3-8007-4957-7 SP - 63 EP - 70 PB - VDE VERLAG CY - Berlin ER - TY - JOUR A1 - Fuhrmann, Thomas A1 - Mottok, Jürgen T1 - Ethical, intercultural and professional impulses integrated into a transmission systems lecture JF - 2017 IEEE Global Engineering Education Conference (EDUCON), 25-28 April 2017, Athens, Greece N2 - In the sixth semester of the bachelor study course “Electrical Engineering and Information Technology”, a lecture “Transmission Systems” is given. It explains basic principles, circuits and systems of electrical and optical transmission systems. Short intellectual impulses, which address professional, intercultural and ethical issues of engineers' working life are integrated into this regular lecture. In each lecture unit, an impulse with one specific topic is given approximately in the middle of the lecture hour. An evaluation was done at the end of the semester, which shows that most of the students remember the discussed topics and state high interest due to high importance for their professional life. Due to these encouraging results, this concept will be developed further. KW - Engineering Education KW - Ethics Education KW - Electrical Engineering Y1 - 2017 U6 - https://doi.org/10.1109/EDUCON.2017.7942829 SP - 92 EP - 95 PB - IEEE ER - TY - CHAP A1 - Thomeczek, Ludwig A1 - Attenberger, Andreas A1 - Kolb, Johannes A1 - Matoušek, Vaclav A1 - Mottok, Jürgen ED - Trinitis, Carsten ED - Pionteck, Thilo T1 - Measuring Safety Critical Latency Sources using Linux Kernel eBPF Tracing T2 - ARCS 2019: 32nd International Conference on Architecture of Computing Systems : workshop proceedings, May 20- 21, 2019, Technical University of Denmark, Copenhagen, Denmark Y1 - 2019 UR - https://ieeexplore.ieee.org/abstract/document/8836200 SN - 978-3-8007-4957-7 PB - VDE VERLAG GMBH CY - Berlin ER - TY - JOUR A1 - Schmid, Michael A1 - Fritz, Florian A1 - Mottok, Jürgen T1 - Fine-Grained Parallel Applications in Real-Time Multiprocessor Systems JF - Journal of Systems Architecture N2 - Lately, parallel task models have received much attention in the development of real-time multiprocessor systems, as they allow highly compute-intensive tasks to have shorter deadlines which is very much required in modern reactive systems. However, missing modularity and portability can make parallel programming a cumbersome endeavor. As a consequence, compute-intensive sectors in the desktop and server segment have relied on parallelism frameworks such as Intel Threading Building Blocks, Cilk and OpenMP. These parallelism frameworks, however, are optimized for decent average case performance and consequently, do not meet the strict requirements imposed by real-time systems. In this paper, we present a proof-of-concept parallelism framework which was implemented in particular for soft real-time systems and having tight timing and safety requirements of such critical systems in mind. The proposed runtime system implements static memory allocation in a work-stealing environment that conforms to the strict space and tight probabilistic time bounds of work-stealing schedulers. Furthermore, we evaluate the performance of this framework by conducting multiprogrammed benchmarks on a real-time embedded multicore architecture. KW - Real-time KW - Work-stealing KW - Thread pool KW - Task model KW - Parallel programming Y1 - 2021 U6 - https://doi.org/10.1016/j.sysarc.2022.102393 VL - 124 PB - Elsevier ER - TY - JOUR A1 - Weiss, Nils A1 - Pozzobon, Enrico A1 - Mottok, Jürgen A1 - Matoušek, Václav T1 - Automated Reverse Engineering of CAN Protocols JF - Neural Network World N2 - Car manufacturers define proprietary protocols to be used inside their vehicular networks, which are kept an industrial secret, therefore impeding independent researchers from extracting information from these networks. This article describes a statistical and a neural network approach that allows reverse engineering proprietary controller area network (CAN)-protocols assuming they were designed using the data base CAN (DBC) file format. The proposed algorithms are tested with CAN traces taken from a real car. We show that our approaches can correctly reverse engineer CAN messages in an automated manner. Y1 - 2021 U6 - https://doi.org/10.14311/NNW.2021.31.015 SN - 1210-0552 VL - 31 IS - 4 SP - 279 EP - 295 ER - TY - CHAP A1 - De, Sangita A1 - Mottok, Jürgen A1 - Brada, Premek ED - Pinker, Jiří T1 - Design Approach to Platform Agnostic Service API Modeling for Interoperability of Cross-enterprise Vehicle Applications T2 - 26th 2021 International Conference on Applied Electronics (AE): 7-8 September 2021, University of West Bohemia, Pilsen, Czech Republik N2 - In the last few years, the collaboration of services between the service-oriented, cross-enterprise vehicle application frameworks has gradually increased to generate novel and more complicated vehicle services for the automotive industry. In these service collaboration scenarios, where heterogeneous application frameworks participate to realize complex vehicle services, a source of discord that emerges is that the service providers must always check, before the service deployment, whether the clients or service consumers on the other side of the communication link are compatible with a given service's API (Application Program Interface). While using standardized templates like ontologies for API's semantic specifications are crucial for a service discovery and semantic interoperability, nevertheless, accessing these service APIs' semantic data using a standardized and understandable syntactical specification template is also equally substantial to ease services interoperability. In fact, such complex service collaboration scenarios motivate this research work which proposes a design approach towards standardized, domain-specific, platform-agnostic semantic and syntactic specification of vehicle services API models. This paper also uses a typical vehicle domain case study to illustrate the design approach and a reference mapping between the platform-agnostic semantics specifications of a vehicle service API ontological model and its corresponding language-neutral, syntactic representation using the OpenAPI standard. KW - interoperability KW - Semantic Web KW - API KW - RESTful KW - ontology Y1 - 2021 SN - 978-80-261-0973-0 U6 - https://doi.org/10.23919/AE51540.2021.9542890 SP - 1 EP - 6 PB - IEEE ER - TY - CHAP A1 - Schmid, Michael A1 - Mottok, Jürgen ED - Queudet, Audrey T1 - Response Time Analysis of Parallel Real-Time DAG Tasks Scheduled by Thread Pools T2 - 29th International Conference on Real-Time Networks and Systems (RTNS 2021): 07.04. - 09 04 2021, Nantes, France N2 - Modern high-end embedded systems nowadays have to process enormous amounts of data. In order to speed up the computations and fully exploit the resources of the underlying hardware architectures, software developers can avail parallelism frameworks such as Intel Threading Building Blocks or compiler extensions as OpenMP. They ease the development of parallel applications by providing interfaces for common parallel design patterns and by internally distributing the work among the workers of a thread pool. However, such frameworks and compiler extensions do not yet support the stringent timing requirements of real-time systems and therefore, an adaption of their computation model to the sector of real-time systems needs to be conducted. In this paper, we address the problem of scheduling parallel real-time directed acyclic graphs tasks on multiprocessor architectures where the subtasks are dispatched among and executed by the workers of a thread pool. In contrast to existing work in the state-of-the-art, we limit the maximum parallelism of real-time tasks not by the number of processors in the system, but by the number of worker threads used in the thread pool of each real-time application. For this model, we derive a worst-case response time analysis for task sets scheduled by a preemptive global fixed-priority scheduler. In order to evaluate the performance of our response time analysis, we further perform schedulability tests on generated task sets and compare the results to existing feasibility analyses in the current state-of-the-art. KW - directed acyclic graph KW - parallel task KW - Real-time systems KW - real-time, scheduling KW - response time analysis KW - thread pool Y1 - 2021 SN - 9781450390019 U6 - https://doi.org/10.1145/3453417.3453419 SP - 173 EP - 183 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - De, Sangita A1 - Niklas, Michael A1 - Brian, Rooney A1 - Mottok, Jürgen A1 - Brada, Premek T1 - Semantic Mapping of Component Framework Interface Ontologies for Interoperability of Vehicle Applications JF - Procedia Computer Science N2 - Over the past few years, ontology merging, and ontology semantic alignment has gained significant interest as research topics in automotive application domain for finding solutions to semantic data heterogeneity. To accomplish the complex and novel vehicle service requirements such as autonomous driving, V2X (Vehicle-to-Vehicle communication), etc. the automotive applications involve collaborations of several platform-specific data from heterogeneous enterprises component frameworks and consequently there has been increase in data interoperability issues. At the application component level, data interoperability relies on the semantic alignment or mapping between the various component framework interfaces data models represented as XML schemas (XSD). With the XML schemas being the preferred standard for the interface description exchange between most of the automotive application domain components, however, the data interoperability between the semantically equivalent but structurally different data constructs of multiple heterogeneous XSDs stands as a challenge in the absence of an ontology-based approach. To confront this crucial requirement for data interoperability and to increase in effect the reuse of existing components through their interfaces, we propose an approach to semantically map the various component framework interface data models when expressed as ontology schemas, based on the exploration of semantic synergies. The transformation between XSD and RDF (Resource Description Framework) schema representations and the use of queries over the ontology schemas for semantic mapping are demonstrated including a real-world case study. KW - component KW - interface KW - mapping KW - ontology KW - semantic Y1 - 2020 U6 - https://doi.org/10.1016/j.procs.2020.03.151 VL - 170 IS - 2 SP - 813 EP - 818 PB - Elsevier ER - TY - CHAP A1 - Altmann, Andreas A1 - Birkner, Wolfgang A1 - Häckl, Franz-Xaver A1 - Hanner, Christopher A1 - Liebhart, Peter A1 - Metschl, Samuel A1 - Weck, Florian A1 - Farmbauer, Michael A1 - Heiß, Manfred A1 - Cuno, H.-H. A1 - Fuhrmann, Thomas A1 - Mandl, Roland A1 - Mottok, Jürgen A1 - Niemetz, Michael T1 - Payload development and launch of a stratosphere balloon mission T2 - IEEE Global Engineering Education Conference (EDUCON 2014), 3-5 April 2014, Istanbul, Turkey N2 - During a student project a stratosphere balloon was developed and launched. This project included the definition of the balloon parameters and the scientific instruments for performing atmospheric measurements, the development of all mechanical and electronic parts, the administration of the project as well as the management tasks related to the balloon launch. The main challenge for the students was the high complexity of the project due to tasks involving many different knowledge domains and the long project duration from the initial definition to the launch. Y1 - 2014 U6 - https://doi.org/10.1109/EDUCON.2014.6826065 ER - TY - JOUR A1 - Raab, Peter A1 - Krämer, Stefan A1 - Mottok, Jürgen T1 - Reliability of data processing and fault compensation in unreliable arithmetic processors, Microprocessors and Microsystems JF - Microprocessors and Microsystems N2 - In logical circuits, like arithmetic operations in a processor system, arbitrary faults become a more tremendous aspect in future. Modern manufacturing processes lead to less reliability and higher vulnerability of software execution to soft-errors. The correctness of certain results is important especially for safety–critical applications whose reliability depends on the fault-free execution of each single instruction and the dependencies between them. The more complex a software is the more unreliable the outcome is. But, there is a contrary effect. If the probability for multiple faults increases, there is also the chance that two faults compensate each other and the result is correct again. This paper presents the basic ideas for such a reliability evaluation of a software's data flow with arbitrary soft-errors and the effect of fault compensation. Further, this evaluation provides a possibility to compare different implementations of a data flow with respect to the reliability. This is shown by the comparison of two different error codes as alternatives for coded data processing. Y1 - 2016 U6 - https://doi.org/10.1016/j.micpro.2015.07.014 VL - 40 IS - Februar SP - 102 EP - 112 PB - Elsevier ER - TY - CHAP A1 - Studt, Reimer A1 - Winterfeldt, Götz A1 - Mottok, Jürgen T1 - Measuring software engineering competencies T2 - 2015 IEEE Global Engineering Education Conference (EDUCON), 18-20 March 2015, Tallinn, Estonia N2 - Measuring competencies may serve as a feedback mechanism as well as a judgment device for a lecturer. As measuring every competency from a catalogue of competencies is not very viable, the to-be-measured competencies are grouped in competency profiles. Further, assessment practices are shown and applied to a course in a study program. A discussion of useful practices concludes this contribution. Y1 - 2015 U6 - https://doi.org/10.1109/EDUCON.2015.7096081 ER - TY - CHAP A1 - Braun, Jürgen A1 - Mottok, Jürgen T1 - The Myths of Coded Processing T2 - IEEE International Conference on High Performance Computing and Communications (HPCC-ICESS-CSS 2015), 24-26 Aug. 2015, New York, USA N2 - Safety of embedded systems has the highest priority because it helps contribute to customer confidence and thereby ensures growth of the new markets, like electromobility. In series production fail-safe systems as well as fault-tolerant systems are realized with redundant hardware concepts like dual core microcontrollers running in lock-step-mode to reach highest safety requirements given by standards, like ISO 26262 or IEC 61508. In contrast to the hardware redundancy approach, there are also approaches available with information-, time-and/or software-redundancy since several years. One of them is known as coded processing or AN-codes. Coded processing is capable of reducing redundancy in hardware by adding diverse redundancy in software. But the breakthrough of coded processing never took place. One reason for this seem to be the myths which are widely propagated on this subject and the hereby associated uncertainties. In this paper some myths are busted, like the usage of prime numbers as transformation factor A, the myth that greater transformation factors are better or the myth about the residual error probability defined as 1/A. Some of them have been propagated since 1989. The aim of this paper is to provide more clarity and understanding for this technique, perhaps to pave the way for further functional safety concepts based on coded processing approaches. KW - Redundancy KW - Hamming distance KW - Safety KW - Encoding KW - Error probability Y1 - 2015 U6 - https://doi.org/10.1109/HPCC-CSS-ICESS.2015.24 SP - 1637 EP - 1644 ER - TY - CHAP A1 - Knorl, Susanne A1 - Soska, Alexander A1 - Schroll-Decker, Irmgard A1 - Mottok, Jürgen T1 - Reconstructing students’ subjective theories on self-directed learning a qualitative research approach in Software Engineering education T2 - 2015 IEEE Global Engineering Education Conference (EDUCON), 18-20 March 2015, Tallinn, Estonia N2 - Considering the claim of furthering self-directed learning in higher education in general and in Software Engineering education in particular, this paper deals with a new approach on understanding and facilitating self-directed learning. This approach involves the concept of subjective theories, which are expected to influence students' self-directed learning. Therefore this paper presents the intended qualitative research design for reconstructing these subjective theories and for developing ways of integrating them in didactical situations in higher education and especially in Software Engineering education. Y1 - 2015 U6 - https://doi.org/10.1109/EDUCON.2015.7095990 SP - 314 EP - 317 ER - TY - CHAP A1 - Soska, Alexander A1 - Mottok, Jürgen A1 - Wolff, Christian T1 - Playful learning in academic software engineering education T2 - 2015 IEEE Global Engineering Education Conference (EDUCON), 18-20 March 2015, Tallinn, Estonia N2 - Within this thesis, we present our suggestions why playful learning in software engineering education is useful to mediate generic competences in academic teaching. Therefor we identified competences which are addressed by playful learning and mapped them to demanded generic competences in software engineering. Due to the well compliance, we analyzed current implementations of playful learning and their design regarding the mediation of required soft skills. Based on the lack of effective implementation, we close our paper with an exemplary design for playful learning. Y1 - 2015 U6 - https://doi.org/10.1109/EDUCON.2015.7095992 SP - 324 EP - 332 ER -