TY - JOUR A1 - Jin, Tonje ED - Meinel, Christoph ED - Schweiger, Stefanie ED - Staubitz, Thomas ED - Conrad, Robert ED - Alario Hoyos, Carlos ED - Ebner, Martin ED - Sancassani, Susanna ED - Żur, Agnieszka ED - Friedl, Christian ED - Halawa, Sherif ED - Gamage, Dilrukshi ED - Scott, Jeffrey ED - Kristine Jonson Carlon, May ED - Deville, Yves ED - Gaebel, Michael ED - Delgado Kloos, Carlos ED - von Schmieden, Karen T1 - “One video fit for all” BT - game inspired online TEACHING in mathematics in STEM education JF - EMOOCs 2023 : Post-Covid Prospects for Massive Open Online Courses - Boost or Backlash? N2 - Online learning in mathematics has always been challenging, especially for mathematics in STEM education. This paper presents how to make “one fit for all” lecture videos for mathematics in STEM education. In general, we do believe that there is no such thing as “one fit for all” video. The curriculum requires a high level of prior knowledge in mathematics from high school to get a good understanding, and the variation of prior knowledge levels among STEM education students is often high. This creates challenges for both online teaching and on-campus teaching. This article presents experimenting and researching on a video format where students can get a real-time feeling, and which fits their needs regarding their existing prior knowledge. They have the possibility to ask and receive answers during the video without having to feel that they must jump into different sources, which helps to reduce unnecessary distractions. The fundamental video format presented here is that of dynamic branching videos, which has to little degree been researched in education related studies. The reason might be that this field is quite new for higher education, and there is relatively high requirement on the video editing skills from the teachers’ side considering the platforms that are available so far. The videos are implemented for engineering students who take the Linear Algebra course at the Norwegian University of Science and Technology in spring 2023. Feedback from the students gathered via anonymous surveys so far (N = 21) is very positive. With the high suitability for online teaching, this video format might lead the trend of online learning in the future. The design and implementation of dynamic videos in mathematics in higher education was presented for the first time at the EMOOCs conference 2023. KW - Digitale Bildung KW - Kursdesign KW - MOOC KW - Micro Degree KW - Online-Lehre KW - Onlinekurs KW - Onlinekurs-Produktion KW - digital education KW - e-learning KW - micro degree KW - micro-credential KW - online course creation KW - online course design KW - online teaching Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-621080 SP - 21 EP - 35 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Kühne, Katharina A1 - Herbold, Erika A1 - Bendel, Oliver A1 - Zhou, Yuefang A1 - Fischer, Martin H. T1 - “Ick bin een Berlina” BT - dialect proficiency impacts a robot’s trustworthiness and competence evaluation JF - Frontiers in robotics and AI N2 - Background: Robots are increasingly used as interaction partners with humans. Social robots are designed to follow expected behavioral norms when engaging with humans and are available with different voices and even accents. Some studies suggest that people prefer robots to speak in the user’s dialect, while others indicate a preference for different dialects. Methods: Our study examined the impact of the Berlin dialect on perceived trustworthiness and competence of a robot. One hundred and twenty German native speakers (Mage = 32 years, SD = 12 years) watched an online video featuring a NAO robot speaking either in the Berlin dialect or standard German and assessed its trustworthiness and competence. Results: We found a positive relationship between participants’ self-reported Berlin dialect proficiency and trustworthiness in the dialect-speaking robot. Only when controlled for demographic factors, there was a positive association between participants’ dialect proficiency, dialect performance and their assessment of robot’s competence for the standard German-speaking robot. Participants’ age, gender, length of residency in Berlin, and device used to respond also influenced assessments. Finally, the robot’s competence positively predicted its trustworthiness. Discussion: Our results inform the design of social robots and emphasize the importance of device control in online experiments. KW - competence KW - dialect KW - human-robot interaction KW - robot voice KW - social robot KW - trust Y1 - 2024 U6 - https://doi.org/10.3389/frobt.2023.1241519 SN - 2296-9144 VL - 10 PB - Frontiers Media S.A. CY - Lausanne ER - TY - JOUR A1 - Casel, Katrin A1 - Fischbeck, Philipp A1 - Friedrich, Tobias A1 - Göbel, Andreas A1 - Lagodzinski, J. A. Gregor T1 - Zeros and approximations of Holant polynomials on the complex plane JF - Computational complexity : CC N2 - We present fully polynomial time approximation schemes for a broad class of Holant problems with complex edge weights, which we call Holant polynomials. We transform these problems into partition functions of abstract combinatorial structures known as polymers in statistical physics. Our method involves establishing zero-free regions for the partition functions of polymer models and using the most significant terms of the cluster expansion to approximate them. Results of our technique include new approximation and sampling algorithms for a diverse class of Holant polynomials in the low-temperature regime (i.e. small external field) and approximation algorithms for general Holant problems with small signature weights. Additionally, we give randomised approximation and sampling algorithms with faster running times for more restrictive classes. Finally, we improve the known zero-free regions for a perfect matching polynomial. KW - Holant problems KW - approximate counting KW - partition functions KW - graph KW - polynomials Y1 - 2022 U6 - https://doi.org/10.1007/s00037-022-00226-5 SN - 1016-3328 SN - 1420-8954 VL - 31 IS - 2 PB - Springer CY - Basel ER - TY - JOUR A1 - Utunen, Heini A1 - Attias, Melissa ED - Meinel, Christoph ED - Schweiger, Stefanie ED - Staubitz, Thomas ED - Conrad, Robert ED - Alario Hoyos, Carlos ED - Ebner, Martin ED - Sancassani, Susanna ED - Żur, Agnieszka ED - Friedl, Christian ED - Halawa, Sherif ED - Gamage, Dilrukshi ED - Scott, Jeffrey ED - Kristine Jonson Carlon, May ED - Deville, Yves ED - Gaebel, Michael ED - Delgado Kloos, Carlos ED - von Schmieden, Karen T1 - xMOOCs BT - modality for mass reach during the pandemic for the World Health Organization JF - EMOOCs 2023 : Post-Covid Prospects for Massive Open Online Courses - Boost or Backlash? N2 - The World Health Organization designed OpenWHO.org to provide an inclusive and accessible online environment to equip learners across the globe with critical up-to-date information and to be able to effectively protect themselves in health emergencies. The platform thus focuses on the eXtended Massive Open Online Course (xMOOC) modality – contentfocused and expert-driven, one-to-many modelled, and self-paced for scalable learning. In this paper, we describe how OpenWHO utilized xMOOCs to reach mass audiences during the COVID-19 pandemic; the paper specifically examines the accessibility, language inclusivity and adaptability of hosted xMOOCs. As of February 2023, OpenWHO had 7.5 million enrolments across 200 xMOOCs on health emergency, epidemic, pandemic and other public health topics available across 65 languages, including 46 courses targeted for the COVID-19 pandemic. Our results suggest that the xMOOC modality allowed OpenWHO to expand learning during the pandemic to previously underrepresented groups, including women, participants ages 70 and older, and learners younger than age 20. The OpenWHO use case shows that xMOOCs should be considered when there is a need for massive knowledge transfer in health emergency situations, yet the approach should be context-specific according to the type of health emergency, targeted population and region. Our evidence also supports previous calls to put intervention elements that contribute to removing barriers to access at the core of learning and health information dissemination. Equity must be the fundamental principle and organizing criteria for public health work. KW - Digitale Bildung KW - Kursdesign KW - MOOC KW - Micro Degree KW - Online-Lehre KW - Onlinekurs KW - Onlinekurs-Produktion KW - digital education KW - e-learning KW - micro degree KW - micro-credential KW - online course creation KW - online course design KW - online teaching Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-624788 SP - 279 EP - 289 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - GEN A1 - Boissier, Martin A1 - Kurzynski, Daniel T1 - Workload-Driven Horizontal Partitioning and Pruning for Large HTAP Systems T2 - 2018 IEEE 34th International Conference on Data Engineering Workshops (ICDEW) N2 - Modern server systems with large NUMA architectures necessitate (i) data being distributed over the available computing nodes and (ii) NUMA-aware query processing to enable effective parallel processing in database systems. As these architectures incur significant latency and throughout penalties for accessing non-local data, queries should be executed as close as possible to the data. To further increase both performance and efficiency, data that is not relevant for the query result should be skipped as early as possible. One way to achieve this goal is horizontal partitioning to improve static partition pruning. As part of our ongoing work on workload-driven partitioning, we have implemented a recent approach called aggressive data skipping and extended it to handle both analytical as well as transactional access patterns. In this paper, we evaluate this approach with the workload and data of a production enterprise system of a Global 2000 company. The results show that over 80% of all tuples can be skipped in average while the resulting partitioning schemata are surprisingly stable over time. Y1 - 2018 SN - 978-1-5386-6306-6 U6 - https://doi.org/10.1109/ICDEW.2018.00026 SP - 116 EP - 121 PB - IEEE CY - New York ER - TY - GEN A1 - Halfpap, Stefan A1 - Schlosser, Rainer T1 - Workload-Driven Fragment Allocation for Partially Replicated Databases Using Linear Programming T2 - 2019 IEEE 35th International Conference on Data Engineering (ICDE) N2 - In replication schemes, replica nodes can process read-only queries on snapshots of the master node without violating transactional consistency. By analyzing the workload, we can identify query access patterns and replicate data depending to its access frequency. In this paper, we define a linear programming (LP) model to calculate the set of partial replicas with the lowest overall memory capacity while evenly balancing the query load. Furthermore, we propose a scalable decomposition heuristic to calculate solutions for larger problem sizes. While guaranteeing the same performance as state-of-the-art heuristics, our decomposition approach calculates allocations with up to 23% lower memory footprint for the TPC-H benchmark. KW - database replication KW - allocation problem KW - linear programming Y1 - 2019 SN - 978-1-5386-7474-1 SN - 978-1-5386-7475-8 U6 - https://doi.org/10.1109/ICDE.2019.00188 SN - 1084-4627 SN - 2375-026X SN - 1063-6382 SP - 1746 EP - 1749 PB - IEEE CY - New York ER - TY - THES A1 - Afifi, Haitham T1 - Wireless In-Network Processing for Multimedia Applications T1 - Drahtlose In-Network-Verarbeitung für Multimedia-Anwendungen N2 - With the recent growth of sensors, cloud computing handles the data processing of many applications. Processing some of this data on the cloud raises, however, many concerns regarding, e.g., privacy, latency, or single points of failure. Alternatively, thanks to the development of embedded systems, smart wireless devices can share their computation capacity, creating a local wireless cloud for in-network processing. In this context, the processing of an application is divided into smaller jobs so that a device can run one or more jobs. The contribution of this thesis to this scenario is divided into three parts. In part one, I focus on wireless aspects, such as power control and interference management, for deciding which jobs to run on which node and how to route data between nodes. Hence, I formulate optimization problems and develop heuristic and meta-heuristic algorithms to allocate wireless and computation resources. Additionally, to deal with multiple applications competing for these resources, I develop a reinforcement learning (RL) admission controller to decide which application should be admitted. Next, I look into acoustic applications to improve wireless throughput by using microphone clock synchronization to synchronize wireless transmissions. In the second part, I jointly work with colleagues from the acoustic processing field to optimize both network and application (i.e., acoustic) qualities. My contribution focuses on the network part, where I study the relation between acoustic and network qualities when selecting a subset of microphones for collecting audio data or selecting a subset of optional jobs for processing these data; too many microphones or too many jobs can lessen quality by unnecessary delays. Hence, I develop RL solutions to select the subset of microphones under network constraints when the speaker is moving while still providing good acoustic quality. Furthermore, I show that autonomous vehicles carrying microphones improve the acoustic qualities of different applications. Accordingly, I develop RL solutions (single and multi-agent ones) for controlling these vehicles. In the third part, I close the gap between theory and practice. I describe the features of my open-source framework used as a proof of concept for wireless in-network processing. Next, I demonstrate how to run some algorithms developed by colleagues from acoustic processing using my framework. I also use the framework for studying in-network delays (wireless and processing) using different distributions of jobs and network topologies. N2 - Mit der steigenden Anzahl von Sensoren übernimmt Cloud Computing die Datenverarbeitung vieler Anwendungen. Dies wirft jedoch viele Bedenken auf, z. B. in Bezug auf Datenschutz, Latenzen oder Fehlerquellen. Alternativ und dank der Entwicklung eingebetteter Systeme können drahtlose intelligente Geräte für die lokale Verarbeitung verwendet werden, indem sie ihre Rechenkapazität gemeinsam nutzen und so eine lokale drahtlose Cloud für die netzinterne Verarbeitung schaffen. In diesem Zusammenhang wird eine Anwendung in kleinere Aufgaben unterteilt, so dass ein Gerät eine oder mehrere Aufgaben ausführen kann. Der Beitrag dieser Arbeit zu diesem Szenario gliedert sich in drei Teile. Im ersten Teil konzentriere ich mich auf drahtlose Aspekte wie Leistungssteuerung und Interferenzmanagement um zu entscheiden, welche Aufgaben auf welchem Knoten ausgeführt werden sollen und wie die Daten zwischen den Knoten weitergeleitet werden sollen. Daher formuliere ich Optimierungsprobleme und entwickle heuristische und metaheuristische Algorithmen zur Zuweisung von Ressourcen eines drahtlosen Netzwerks. Um mit mehreren Anwendungen, die um diese Ressourcen konkurrieren, umgehen zu können, entwickle ich außerdem einen Reinforcement Learning (RL) Admission Controller, um zu entscheiden, welche Anwendung zugelassen werden soll. Als Nächstes untersuche ich akustische Anwendungen zur Verbesserung des drahtlosen Durchsatzes, indem ich Mikrofon-Taktsynchronisation zur Synchronisierung drahtloser Übertragungen verwende. Im zweiten Teil arbeite ich mit Kollegen aus dem Bereich der Akustikverarbeitung zusammen, um sowohl die Netzwerk- als auch die Anwendungsqualitäten (d.h. die akustischen) zu optimieren. Mein Beitrag konzentriert sich auf den Netzwerkteil, wo ich die Beziehung zwischen akustischen und Netzwerkqualitäten bei der Auswahl einer Teilmenge von Mikrofonen für die Erfassung von Audiodaten oder der Auswahl einer Teilmenge von optionalen Aufgaben für die Verarbeitung dieser Daten untersuche; zu viele Mikrofone oder zu viele Aufgaben können die Qualität durch unnötige Verzögerungen verringern. Daher habe ich RL-Lösungen entwickelt, um die Teilmenge der Mikrofone unter Netzwerkbeschränkungen auszuwählen, wenn sich der Sprecher bewegt, und dennoch eine gute akustische Qualität gewährleistet. Außerdem zeige ich, dass autonome Fahrzeuge, die Mikrofone mit sich führen, die akustische Qualität verschiedener Anwendungen verbessern. Dementsprechend entwickle ich RL-Lösungen (Einzel- und Multi-Agenten-Lösungen) für die Steuerung dieser Fahrzeuge. Im dritten Teil schließe ich die Lücke zwischen Theorie und Praxis. Ich beschreibe die Eigenschaften meines Open-Source-Frameworks, das als Prototyp für die drahtlose netzinterne Verarbeitung verwendet wird. Anschließend zeige ich, wie einige Algorithmen, die von Kollegen aus der Akustikverarbeitung entwickelt wurden, mit meinem Framework ausgeführt werden können. Außerdem verwende ich das Framework für die Untersuchung von netzinternen Verzögerungen unter Verwendung verschiedener Aufgabenverteilungen und Netzwerktopologien. KW - wireless networks KW - reinforcement learning KW - network optimization KW - Netzoptimierung KW - bestärkendes Lernen KW - drahtloses Netzwerk Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-604371 ER - TY - JOUR A1 - Khalil, Mohammad T1 - Who Are the Students of MOOCs? BT - Experience from Learning Analytics Clustering Techniques JF - EMOOCs 2021 N2 - Clustering in education is important in identifying groups of objects in order to find linked patterns of correlations in educational datasets. As such, MOOCs provide a rich source of educational datasets which enable a wide selection of options to carry out clustering and an opportunity for cohort analyses. In this experience paper, five research studies on clustering in MOOCs are reviewed, drawing out several reasonings, methods, and students’ clusters that reflect certain kinds of learning behaviours. The collection of the varied clusters shows that each study identifies and defines clusters according to distinctive engagement patterns. Implications and a summary are provided at the end of the paper. Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-517298 SN - 978-3-86956-512-5 VL - 2021 SP - 259 EP - 269 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - GEN A1 - Ladleif, Jan A1 - Weske, Mathias T1 - Which Event Happened First? Deferred Choice on Blockchain Using Oracles T2 - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät N2 - First come, first served: Critical choices between alternative actions are often made based on events external to an organization, and reacting promptly to their occurrence can be a major advantage over the competition. In Business Process Management (BPM), such deferred choices can be expressed in process models, and they are an important aspect of process engines. Blockchain-based process execution approaches are no exception to this, but are severely limited by the inherent properties of the platform: The isolated environment prevents direct access to external entities and data, and the non-continual runtime based entirely on atomic transactions impedes the monitoring and detection of events. In this paper we provide an in-depth examination of the semantics of deferred choice, and transfer them to environments such as the blockchain. We introduce and compare several oracle architectures able to satisfy certain requirements, and show that they can be implemented using state-of-the-art blockchain technology. T3 - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät - 11 KW - business processes KW - business process management KW - deferred choice KW - workflow patterns KW - blockchain KW - smart contracts KW - oracles KW - formal semantics Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-550681 VL - 4 SP - 1 EP - 16 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Ladleif, Jan A1 - Weske, Mathias T1 - Which event happened first? BT - Deferred choice on blockchain using oracles JF - Frontiers in blockchain N2 - First come, first served: Critical choices between alternative actions are often made based on events external to an organization, and reacting promptly to their occurrence can be a major advantage over the competition. In Business Process Management (BPM), such deferred choices can be expressed in process models, and they are an important aspect of process engines. Blockchain-based process execution approaches are no exception to this, but are severely limited by the inherent properties of the platform: The isolated environment prevents direct access to external entities and data, and the non-continual runtime based entirely on atomic transactions impedes the monitoring and detection of events. In this paper we provide an in-depth examination of the semantics of deferred choice, and transfer them to environments such as the blockchain. We introduce and compare several oracle architectures able to satisfy certain requirements, and show that they can be implemented using state-of-the-art blockchain technology. KW - business processes KW - business process management KW - deferred choice KW - workflow patterns KW - blockchain KW - smart contracts KW - oracles KW - formal semantics Y1 - 2021 U6 - https://doi.org/10.3389/fbloc.2021.758169 SN - 2624-7852 VL - 4 SP - 1 EP - 16 PB - Frontiers in Blockchain CY - Lausanne, Schweiz ER -