University of Applied Sciences Emden Leer
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509 research outputs found
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Constructing and Deconstructing Intentional Weaknesses in Symmetric Ciphers
No full textDeliberately weakened ciphers are of great interest in political discussion on law enforcement, as in the constantly recurring crypto wars, and have been put in the spotlight of academics by recent progress. A paper at Eurocrypt 2021 showed a strong indication that the security of the widely-deployed stream cipher GEA-1 was deliberately and secretly weakened to 40 bits in order to fulfill European export restrictions that have been in place in the late 1990s. However, no explanation of how this could have been constructed was given. On the other hand, we have seen the MALICIOUS design framework, published at CRYPTO 2020, that allows to construct tweakable block ciphers with a backdoor, where the difficulty of recovering the backdoor relies on well-understood cryptographic assumptions. The constructed tweakable block cipher however is rather unusual and very different from, say, general-purpose ciphers like the AES.
In this paper, we pick up both topics. For GEA-1 we thoroughly explain how the weakness was constructed, solving the main open question of the work mentioned above. By generalizing MALICIOUS we – for the first time – construct backdoored tweakable block ciphers that follow modern design principles for general-purpose block ciphers, i.e., more natural-looking deliberately weakened tweakable block ciphers
Archaeology as “self-therapy”: Case studies of metal detecting communities in Britain and Denmark
No full textThe article presents the results of two online questionaire surveys, focussing on the use of metal detecting for archaeological items as a form of self-therapy. The surveys focused on two different cohorts; British armed forces veterans with (un)diagnosed mental health challenges and Danish detectorists with and without (un)diagnosed mental health challenges. We conclude that active metal detector users with diagnosed and undiagnosed mental health problems perceive metal detecting as having a beneficial effect on their health and wellbeing. A majority of users also feel that the hobby mitigates diagnosis-specific symptoms of their psychological problems. Further, a large number of Danish detectorists with pre-existing mental health conditions perceive their hobby as a relief from the general stress caused by the Covid-19 situation in 2020. Our results to date provide some insight as to whether metal detecting can be used as an activity to support mental health and impact as a “self-therapy”. Moving forward, we are trying to establish the necessary data for answering this question through the ‘‘Vetektor-Buddy-program” – a scheme introducing Danish armed forces veterans to the metal detector hobby
Sustainable Hyperautomation in High-Tech Manufacturing Industries: A Case of Linear Electromechanical Actuators
No full textHyperautomation is a promising but sparingly implemented concept in intelligent manufacturing. One of the reasons for the suboptimal adoption of hyperautomation is the large gap between current theoretical frameworks and practical methodologies and tools that can be applied in a real industrial production scenario. This situation has become much more complicated in high-tech enterprises, which face a particular set of issues in terms of innovation, cost-effectiveness, and supply chain management in today’s globalized environment. This manuscript provides a new conceptual business framework and technological background for achieving sustainable hyperautomation in the manufacturing of linear electromechanical actuators (LEMA), a key component of several cyberphysical actuators. A set of digital tools and innovative concepts, such as intra-enterprise 3-level factory and definitive designs based on unified solutions, which enable mass customization and offer up to 1000 variants of the LEMAs, are introduced to achieve synergistic interaction between different business functions and provide significant cost and technological advantages. To make manufacturing more customizable, a modular design approach is used, and simultaneously, to facilitate mass production, the focus is given on roller screw transmission modules, representing approximately three-fourths of the added value of LEMA. Furthermore, the concept of synergetic forward integration is proposed and explained using an example of robotic resistance spot welding. This framework involves a closed loop of industrial mature digital tools that enables autonomous product design and manufacturing via Responsive R&D (Research and Development) and feedback-driven dynamic interactions with the market and production system. These steps allow intelligent and automatic decision making throughout the digitally connected systems within the company and out of the company through a digital networked connected intra-enterprise world inside the supply chain with minimal human intervention
Welche Merkmale zeigt eine vollimmersive Mehrpersonen-VR-Simulation im Vergleich zum Einsatz von Videokonferenzsoftware in Gruppenarbeitsprozessen?
No full textDer Einsatz von vollimmersiven VR-Lernumgebungen fördert bei Lernenden die individuellen Fähigkeiten und ihr Vorwissen. Konkrete Lerneffekte und Integrationskonzepte sind jedoch noch nicht ausreichend untersucht. Im Rahmen eines vom BMBF geförderten Forschungsprojektes soll mit diesem Beitrag deshalb der Frage nachgegangen werden: Welche didaktisch-gestalterischen sowie kommunikativ-interaktiven Unterschiede zeigen vollimmersive virtuelle Lernumgebungen gegenüber dem Einsatz von Videokonferenzsoftware im Kontext der Gruppenarbeit? Das Ziel ist es, den Einsatz von Multiplayer-VR-Szenarien der Nutzung von Videokonferenztools für Gruppenarbeitsprozesse im Rahmen der Fallarbeit gegenüberzustellen und deren Vor- und Nachteile aufzuzeigen. Die Ergebnisse zeigen, dass sich für Gruppenarbeitsprozesse in beiden Formaten Vor- und Nachteile finden lassen. Die Umsetzung des Konzeptes der Fallarbeit fällt jedoch in beiden Formaten positiv aus. Folglich ist der Erfolg einer Gruppenarbeit von der konzeptionellen Einbindung der Methode in den Lehrkontext abhängig, sodass die Form der Umsetzung vorwiegend Einfluss auf die Performanz nimmt. Zukünftig gilt es, konkrete Implementierungskonzepte für den Einsatz von VR-Anwendungen in der Lehre zu entwickeln und zu erproben
Plasmon-Enhanced Exciton Delocalization in Squaraine-Type Molecular Aggregates
No full textEnlarging exciton coherence lengths in molecular aggregates is critical for enhancing the collective optical and transport properties of molecular thin film nanostructures or devices. We demonstrate that the exciton coherence length of squaraine aggregates can be increased from 10 to 24 molecular units at room temperature when preparing the aggregated thin film on a metallic rather than a dielectric substrate. Two-dimensional electronic spectroscopy measurements reveal a much lower degree of inhomogeneous line broadening for aggregates on a gold film, pointing to a reduced disorder. The result is corroborated by simulations based on a Frenkel exciton model including exciton–plasmon coupling effects. The simulation shows that localized, energetically nearly resonant excitons on spatially well separated segments can be radiatively coupled via delocalized surface plasmon polariton modes at a planar molecule–gold interface. Such plasmon-enhanced delocalization of the exciton wave function is of high importance for improving the coherent transport properties of molecular aggregates on the nanoscale. Additionally, it may help tailor the collective optical response of organic materials for quantum optical applications
Rabi Oscillations in Disguise: Strong Exciton-Surface Plasmon Polariton Coupling Probed by Two-Dimensional Electronic Spectroscopy
No full textWe explore dynamics of strong exciton-plasmon couplings using two-dimensional electronic spectra displaying pronounced Rabi oscillations of their cross-peaks. Radiative couplings govern the polariton nonlinearity and provide first access to the two-quantum-excitations of the coupled system
3D-Objekterkennung mit Jetson Nano und Integration mit KUKA KR6-Roboter für autonomes Pick-and-Place
No full textBildverarbeitungssysteme bieten innovative Lösungen für den Fertigungsprozess. Kameras und zugehörige Bildverarbeitungssysteme können zur Identifizierung, Prüfung und Lokalisierung von Teilen auf einem Förderband oder in einem Behälter mit Teilen eingesetzt werden. Roboter werden dann eingesetzt,um jedes Teil aufzunehmen und im Montagebereich zu platzieren oder sogar um die Grundmontage direkt durchzuführen. Das System für dieses Projekt besteht aus einem Roboter Kuka KR6 900, der die Position (x-, y- und z-Koordinaten des Objektschwerpunkts) und die Ausrichtung eines Bauteils von einem Bildverarbeitungssystem basierend auf einem Jetson Nano erhält. Das Ziel dieses Projekts ist es, eine automatische Erkennung eines Objekts mit Hilfe einer 2D-Kamera und der Auswertung mit dem Deep Learning Algorithmus Darknet YOLO V4 durchzuführen, so dass der Roboter das Objekt greifen und platzieren kann. Dieses Projekt verwendet zwei verschiedene Objekttypen: einen Quader und einen Zylinder. Die Bilderkennung erfolgt mit Hilfe des Jetson Nano, dort erfolgt aus den Pixelkoordinaten die Berechnung der realen Koordinaten, die dann über die TCP/IP-Schnittstelle des Kuka KR6 900 zur Durchführung der Entnahme und Platzierung übermittelt werden. Die Flexibilität des Roboters, dessen Steuerung auf diese Weise von der Bildverarbeitung unterstützt wird, kann den Bedarf an präzise konstruierten Teilezuführungen verringern und so die Flexibilität in der Fertigungszelle erhöhen und kurze Produktionsläufe und Anpassungsfähigkeit ermöglichen
Economic, technological and social drivers of cryptocurrency market evolution and its managerial impact
No full textCryptocurrencies, such as Bitcoin, have caused intense discussions during recent years among market participants according to new options (such as payment or financing alternatives) and new risks (such as price volatility) involved. Despite being considered by various actors of private households, companies, financial, monetary, and political institutions, a theory-based understanding of this innovation and knowledge of their evolution is still limited. On a basic level, this holds for differences between cryptocurrencies on the one hand and traditional currencies, like paper money, gold or special assets, on the other. On a market level, factors driving the prices of cryptocurrencies appear to be of seminal meaning, in particular against the backdrop of recent market turmoil. Therefore, the paper conducts an empirical analysis of the five biggest cryptocurrencies (measured by market capitalization) with regard to their evolutionary development, price behaviour, and their impact for manager
Options for connecting decentralized data infrastructure to improve Supply-Chain decision making without giving up individual data property
No full textWe present research on the topic of horizontal Supply-Chain data integration. This paper starts with a quick overview on the state of Supply-Chain intercompany communication. We will discuss the state of the connection between Supply-Chain members and the reasons why, especially small and medium businesses, have reservations on sharing data within their Supply-Chain. After that, we will look at existing architectures and concepts for analysis of distributed data. The paper will discuss under which assumptions and conditions the different identified solutions are able to connect the data infrastructure in the Supply-Chain
Architecture Framework for Intelligence Orchestration in AIoT and IoT
No full textThe emergence of novel architectures such as fog and edge computing have blurred the boundaries between the network core and its periphery leading the Internet towards a computer board equivalent, while keeping the inherent distribution of the original Internet. In this paper, we present a novel architecture using an Intelligence Orchestration approach that is needed in this new network continuum computing paradigm. We aim to tackle the series of challenges of such as heterogeneity of stakeholders, use case and type of business dynamics, in addition to hardware and platforms by providing an “operating system” (OS) like design. The principles of the architecture are described and its advantages and needed next steps are also discussed