TY - THES A1 - Reitwießner, Christian T1 - Multiobjective Optimization and Language Equations T1 - Mehrkriterielle Optimierung und Sprachgleichungen N2 - Praktische Optimierungsprobleme beinhalten oft mehrere gleichberechtigte, sich jedoch widersprechende Kriterien. Beispielsweise will man bei einer Reise zugleich möglichst schnell ankommen, sie soll aber auch nicht zu teuer sein. Im ersten Teil dieser Arbeit wird die algorithmische Beherrschbarkeit solcher mehrkriterieller Optimierungsprobleme behandelt. Es werden zunächst verschiedene Lösungsbegriffe diskutiert und auf ihre Schwierigkeit hin verglichen. Interessanterweise stellt sich heraus, dass diese Begriffe für ein einkriterielles Problem stets gleich schwer sind, sie sich ab zwei Kriterien allerdings stark unterscheiden könen (außer es gilt P = NP). In diesem Zusammenhang wird auch die Beziehung zwischen Such- und Entscheidungsproblemen im Allgemeinen untersucht. Schließlich werden neue und verbesserte Approximationsalgorithmen für verschieden Varianten des Problems des Handlungsreisenden gefunden. Dabei wird mit Mitteln der Diskrepanztheorie eine Technik entwickelt, die ein grundlegendes Hindernis der Mehrkriteriellen Optimierung aus dem Weg schafft: Gegebene Lösungen so zu kombinieren, dass die neue Lösung in allen Kriterien möglichst ausgewogen ist und gleichzeitig die Struktur der Lösungen nicht zu stark zerstört wird. Der zweite Teil der Arbeit widmet sich verschiedenen Aspekten von Gleichungssystemen für (formale) Sprachen. Einerseits werden konjunktive und Boolesche Grammatiken untersucht. Diese sind Erweiterungen der kontextfreien Grammatiken um explizite Durchschnitts- und Komplementoperationen. Es wird unter anderem gezeigt, dass man bei konjunktiven Grammatiken die Vereinigungsoperation stark einschränken kann, ohne dabei die erzeugte Sprache zu ändern. Außerdem werden bestimmte Schaltkreise untersucht, deren Gatter keine Wahrheitswerte sondern Mengen von Zahlen berechnen. Für diese Schaltkreise wird das Äquivalenzproblem betrachtet, also die Frage ob zwei gegebene Schaltkreise die gleiche Menge berechnen oder nicht. Es stellt sich heraus, dass, abhängig von den erlaubten Gattertypen, die Komplexität des Äquivalenzproblems stark variiert und für verschiedene Komplexitätsklassen vollständig ist, also als (parametrisierter) Vertreter für diese Klassen stehen kann. N2 - Practical optimization problems often comprise several incomparable and conflicting objectives. When booking a trip using several means of transport, for instance, it should be fast and at the same time not too expensive. The first part of this thesis is concerned with the algorithmic solvability of such multiobjective optimization problems. Several solution notions are discussed and compared with respect to their difficulty. Interestingly, these solution notions are always equally difficulty for a single-objective problem and they differ considerably already for two objectives (unless P = NP). In this context, the difference between search and decision problems is also investigated in general. Furthermore, new and improved approximation algorithms for several variants of the traveling salesperson problem are presented. Using tools from discrepancy theory, a general technique is developed that helps to avoid an obstacle that is often hindering in multiobjective approximation: The problem of combining two solutions such that the new solution is balanced in all objectives and also mostly retains the structure of the original solutions. The second part of this thesis is dedicated to several aspects of systems of equations for (formal) languages. Firstly, conjunctive and Boolean grammars are studied, which are extensions of context-free grammars by explicit intersection and complementation operations, respectively. Among other results, it is shown that one can considerably restrict the union operation on conjunctive grammars without changing the generated language. Secondly, certain circuits are investigated whose gates do not compute Boolean values but sets of natural numbers. For these circuits, the equivalence problem is studied, i.\,e.\ the problem of deciding whether two given circuits compute the same set or not. It is shown that, depending on the allowed types of gates, this problem is complete for several different complexity classes and can thus be seen as a parametrized) representative for all those classes. KW - Mehrkriterielle Optimierung KW - Approximationsalgorithmus KW - Travelling-salesman-Problem KW - Boolesche Grammatik KW - Theoretische Informatik KW - Komplexitätstheorie KW - Boolean Grammar Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-70146 ER - TY - JOUR A1 - Riedmann, Anna A1 - Schaper, Philipp A1 - Lugrin, Birgit T1 - Integration of a social robot and gamification in adult learning and effects on motivation, engagement and performance JF - AI & Society N2 - Learning is a central component of human life and essential for personal development. Therefore, utilizing new technologies in the learning context and exploring their combined potential are considered essential to support self-directed learning in a digital age. A learning environment can be expanded by various technical and content-related aspects. Gamification in the form of elements from video games offers a potential concept to support the learning process. This can be supplemented by technology-supported learning. While the use of tablets is already widespread in the learning context, the integration of a social robot can provide new perspectives on the learning process. However, simply adding new technologies such as social robots or gamification to existing systems may not automatically result in a better learning environment. In the present study, game elements as well as a social robot were integrated separately and conjointly into a learning environment for basic Spanish skills, with a follow-up on retained knowledge. This allowed us to investigate the respective and combined effects of both expansions on motivation, engagement and learning effect. This approach should provide insights into the integration of both additions in an adult learning context. We found that the additions of game elements and the robot did not significantly improve learning, engagement or motivation. Based on these results and a literature review, we outline relevant factors for meaningful integration of gamification and social robots in learning environments in adult learning. KW - social robot KW - gamification KW - technology-supported learning KW - adult learning Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324208 SN - 0951-5666 ER - TY - RPRT A1 - Riegler, Clemens A1 - Kayal, Hakan T1 - VELEX: Venus Lightning Experiment N2 - Lightning has fascinated humanity since the beginning of our existence. Different types of lightning like sprites and blue jets were discovered, and many more are theorized. However, it is very likely that these phenomena are not exclusive to our home planet. Venus’s dense and active atmosphere is a place where lightning is to be expected. Missions like Venera, Pioneer, and Galileo have carried instruments to measure electromagnetic activity. These measurements have indeed delivered results. However, these results are not clear. They could be explained by other effects like cosmic rays, plasma noise, or spacecraft noise. Furthermore, these lightning seem different from those we know from our home planet. In order to tackle these issues, a different approach to measurement is proposed. When multiple devices in different spacecraft or locations can measure the same atmospheric discharge, most other explanations become increasingly less likely. Thus, the suggested instrument and method of VELEX incorporates multiple spacecraft. With this approach, the question about the existence of lightning on Venus could be settled. T3 - Raumfahrttechnik und Extraterrestrik - 3 KW - Venus KW - Lightning KW - CubeSat KW - Balloon KW - Autorotation Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-282481 ER - TY - RPRT A1 - Riegler, Clemens A1 - Werner, Lennart A1 - Kayal, Hakan T1 - MAPLE: Marsian Autorotation Probe Lander Experiment N2 - The first step towards aerial planetary exploration has been made. Ingenuity shows extremely promising results, and new missions are already underway. Rotorcraft are capable of flight. This capability could be utilized to support the last stages of Entry, Descent, and Landing. Thus, mass and complexity could be scaled down. Autorotation is one method of descent. It describes unpowered descent and landing, typically performed by helicopters in case of an engine failure. MAPLE is suggested to test these procedures and understand autorotation on other planets. In this series of experiments, the Ingenuity helicopter is utilized. Ingenuity would autorotate a ”mid-air-landing” before continuing with normal flight. Ultimately, the collected data shall help to understand autorotation on Mars and its utilization for interplanetary exploration. T3 - Raumfahrttechnik und Extraterrestrik - 2 KW - autorotation KW - descent KW - Mars KW - rotorcraft KW - landing KW - aerospace Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-282390 ER - TY - JOUR A1 - Rodrigues, Johannes A1 - Weiß, Martin A1 - Hewig, Johannes A1 - Allen, John J. B. T1 - EPOS: EEG Processing Open-Source Scripts JF - Frontiers in Neuroscience N2 - Background: Since the replication crisis, standardization has become even more important in psychological science and neuroscience. As a result, many methods are being reconsidered, and researchers’ degrees of freedom in these methods are being discussed as a potential source of inconsistencies across studies. New Method: With the aim of addressing these subjectivity issues, we have been working on a tutorial-like EEG (pre-)processing pipeline to achieve an automated method based on the semi-automated analysis proposed by Delorme and Makeig. Results: Two scripts are presented and explained step-by-step to perform basic, informed ERP and frequency-domain analyses, including data export to statistical programs and visual representations of the data. The open-source software EEGlab in MATLAB is used as the data handling platform, but scripts based on code provided by Mike Cohen (2014) are also included. Comparison with existing methods: This accompanying tutorial-like article explains and shows how the processing of our automated pipeline affects the data and addresses, especially beginners in EEG-analysis, as other (pre)-processing chains are mostly targeting rather informed users in specialized areas or only parts of a complete procedure. In this context, we compared our pipeline with a selection of existing approaches. Conclusion: The need for standardization and replication is evident, yet it is equally important to control the plausibility of the suggested solution by data exploration. Here, we provide the community with a tool to enhance the understanding and capability of EEG-analysis. We aim to contribute to comprehensive and reliable analyses for neuro-scientific research. KW - EEG KW - electroencephalography KW - event-related potentials-ERP KW - EEG processing KW - EEG preprocessing KW - EEG frequency band analysis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-240221 SN - 1662-453X VL - 15 ER - TY - RPRT A1 - Rossa, Christian T1 - Inside 2004: Multimedia und Services T1 - Inside 2004: Multimedia and Services N2 - Einzelne Artikel zu den Themen Multimedia, Dienstleistungen, IT-Sicherheit und Hochschulnetz des Rechenzentrums der Universität Würzburg N2 - Some articles concerning multimedia, services, IT security and university network in the computer center of the University of Wuerzburg KW - Multimedia KW - Dienstleistungen KW - IT-Sicherheit KW - Hochschulnetz KW - Multimedia KW - Services KW - IT Security KW - university network Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-8616 ER - TY - GEN A1 - Rossa, Christian T1 - Inside 2003: IT-Sicherheit T1 - Inside 2003: IT Security N2 - Einzelne Artikel zum Thema IT-Sicherheit an der Universität Würzburg N2 - Some articles concerning IT security at the University of Wuerzburg KW - Datenübertragung ; Datensicherung ; Informationstechnik ; Internet ; Computersicherheit KW - IT-Sicherheit KW - Firewall KW - Computervirus KW - Spam-Mail KW - Webmail-System KW - IT Security KW - firewall KW - computer virus KW - spam mail KW - webmail system Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-6061 ER - TY - RPRT A1 - Rossi, Angelo Pio A1 - Maurelli, Francesco A1 - Unnithan, Vikram A1 - Dreger, Hendrik A1 - Mathewos, Kedus A1 - Pradhan, Nayan A1 - Corbeanu, Dan-Andrei A1 - Pozzobon, Riccardo A1 - Massironi, Matteo A1 - Ferrari, Sabrina A1 - Pernechele, Claudia A1 - Paoletti, Lorenzo A1 - Simioni, Emanuele A1 - Maurizio, Pajola A1 - Santagata, Tommaso A1 - Borrmann, Dorit A1 - Nüchter, Andreas A1 - Bredenbeck, Anton A1 - Zevering, Jasper A1 - Arzberger, Fabian A1 - Reyes Mantilla, Camilo Andrés T1 - DAEDALUS - Descent And Exploration in Deep Autonomy of Lava Underground Structures BT - Open Space Innovation Platform (OSIP) Lunar Caves-System Study N2 - The DAEDALUS mission concept aims at exploring and characterising the entrance and initial part of Lunar lava tubes within a compact, tightly integrated spherical robotic device, with a complementary payload set and autonomous capabilities. The mission concept addresses specifically the identification and characterisation of potential resources for future ESA exploration, the local environment of the subsurface and its geologic and compositional structure. A sphere is ideally suited to protect sensors and scientific equipment in rough, uneven environments. It will house laser scanners, cameras and ancillary payloads. The sphere will be lowered into the skylight and will explore the entrance shaft, associated caverns and conduits. Lidar (light detection and ranging) systems produce 3D models with high spatial accuracy independent of lighting conditions and visible features. Hence this will be the primary exploration toolset within the sphere. The additional payload that can be accommodated in the robotic sphere consists of camera systems with panoramic lenses and scanners such as multi-wavelength or single-photon scanners. A moving mass will trigger movements. The tether for lowering the sphere will be used for data communication and powering the equipment during the descending phase. Furthermore, the connector tether-sphere will host a WIFI access point, such that data of the conduit can be transferred to the surface relay station. During the exploration phase, the robot will be disconnected from the cable, and will use wireless communication. Emergency autonomy software will ensure that in case of loss of communication, the robot will continue the nominal mission. T3 - Forschungsberichte in der Robotik = Research Notes in Robotics - 21 KW - Lunar Caves KW - Spherical Robot KW - Lunar Exploration KW - Mapping KW - 3D Laser Scanning KW - Mond KW - Daedalus-Projekt KW - Lava Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227911 SN - 978-3-945459-33-1 SN - 1868-7466 ER - TY - CHAP A1 - Sanusi, Khaleel Asyraaf Mat A1 - Klemke, Roland T1 - Immersive Multimodal Environments for Psychomotor Skills Training T2 - Proceedings of the 1st Games Technology Summit N2 - Modern immersive multimodal technologies enable the learners to completely get immersed in various learning situations in a way that feels like experiencing an authentic learning environment. These environments also allow the collection of multimodal data, which can be used with artificial intelligence to further improve the immersion and learning outcomes. The use of artificial intelligence has been widely explored for the interpretation of multimodal data collected from multiple sensors, thus giving insights to support learners’ performance by providing personalised feedback. In this paper, we present a conceptual approach for creating immersive learning environments, integrated with multi-sensor setup to help learners improve their psychomotor skills in a remote setting. KW - immersive learning technologies KW - multimodal learning KW - sensor devices KW - artificial intelligence KW - psychomotor training Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246016 ER - TY - THES A1 - Saska, Martin T1 - Trajectory planning and optimal control for formations of autonomous robots T1 - Die Bahnplanung und die optimale Steuerung für Formationen der autonomen Roboter N2 - In this thesis, we present novel approaches for formation driving of nonholonomic robots and optimal trajectory planning to reach a target region. The methods consider a static known map of the environment as well as unknown and dynamic obstacles detected by sensors of the formation. The algorithms are based on leader following techniques, where the formation of car-like robots is maintained in a shape determined by curvilinear coordinates. Beyond this, the general methods of formation driving are specialized and extended for an application of airport snow shoveling. Detailed descriptions of the algorithms complemented by relevant stability and convergence studies will be provided in the following chapters. Furthermore, discussions of the applicability will be verified by various simulations in existing robotic environments and also by a hardware experiment. N2 - In dieser Arbeit präsentieren wir neuartige Algorithmen für die Steuerung der Formationen der nichtholonomen Roboter und ihre optimale Bahnplanung. Die Algorithmen beruhen auf "leader-follower" Techniken. Die Formationen der "car-like" Roboter sind in einer bestimmten Form von "curvilinear" Koordinaten gehalten. Die Steuerungmethoden der Formationen sind spezialisiert und erweitert um ihre Anwendung auf das Flughafenschneeschaufeln. In dieser Arbeit werden die detaillierten Beschreibungen der Algorithmen durch entsprechende Stabilität- und Konvergenz-Studien gestellt. Ihre Anwendbarkeit wird durch verschiedene Simulationen und eine Hardware-Experiment überprüft. T3 - Forschungsberichte in der Robotik = Research Notes in Robotics - 3 KW - Autonomer Roboter KW - Mobiler Roboter KW - Optimale Kontrolle KW - Formation KW - Steuerung KW - formation driving KW - mobile robots KW - snow shoveling KW - receding horizon control KW - model predictive control KW - trajectory planning Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-53175 SN - 978-3-923959-56-3 ER -