Now showing 1 - 10 of 35
  • Publication
    An Agnostic Domain Specific Language for Implementing Attacks in an Automotive Use Case
    This paper presents a Domain Specific Language (DSL) for generically describing cyber attacks, agnostic to specific system-under-test (SUT). The creation of the presented DSL is motivated by an automotive use case. The concepts of the DSL are generic such that attacks on arbitrary systems can be addressed. The ongoing trend to improve the user experience of vehicles with connected services implies an enhanced connectivity as well as remote accessible interface opens potential attack vectors. This might also impact safety and the proprietary nature of potential SUTs. Reusing tests of attack vectors to industrialize testing them on multiple SUTs mandates an abstraction mechanism to port an attack from one system to another. The DSL therefore generically describes attacks for the usage with a test case generator (and execution environment) also described in this paper. The latter use this description and a database with SUT-specific information to generate attack implementations for a multitude of different (automotive) SUTs.
  • Publication
    Heat exchangers from metal-bonded La(Fe,Mn,Si)13Hx powder
    ( 2017)
    Radulov, Iliya A.
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    Karpenkov, Dmitriy Y.
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    Specht, Marius
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    Karpenkov, Alexey Y.
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    Skokov, Konstantin P.
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    Hydrogenated La(Fe,Mn,Si)13-based alloys have an excellent magnetocaloric properties, but poor mechanical and chemical stability. This hinders their direct machining and implementation in an active magnetic regenerator (AMR). In this paper, we show how machinability and corrosion protection of the particles can be improved by a hot-dip coating. To avoid the loss of hydrogen during the coating process, a low melting temperature eutectic Bi-Sn-In alloy was selected as a metal binder. The coated particles were used to build a packed bed regenerator as an array of fixed particles, avoiding such negative effects as sedimentation, segregation, and channel deformation. Similarity theory, combined with unsteady heat transfer approach was applied in order to calculate the optimal operation frequency and to estimate the maximal cooling power of the magnetocaloric regenerators. Two different geometries of heat exchangers were theoretically compared: stacked flat plate/channel structure and packed bed of equidimensional spherical particles. It is shown that, operating at low frequency, the same amount of magnetocaloric material can expel bigger amount of heat, when formed as packed bed heat exchangers. The metal-bonded packed bed regenerator made from La(Fe,Mn,Si)13Hx powder was tested in a home-build versatile testing device in a magnetic field change of 10 kOe. The maximal achievable temperature span as a function of both parameters-hot end temperature and length of regenerator-was explored. The largest thermal span of 8 K was produced by the regenerator with 40 mm length.
  • Publication
    FERAL - Framework for Simulator Coupling on Requirements and Architecture Level
    ( 2013) ;
    Forster, Thomas
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    Gotzhein, Reinhard
    Simulation technologies are imperative for embedded systems development. They enable the evaluation of decisions already early in development processes. Simulators are focused on a subset of effects that affect the operation of embedded systems. Accurate prediction of embedded system behavior on system level, however, requires the consideration of multiple effects, e.g. communication behavior, system environments, and functional behavior of all relevant system components. This requires the coupling of specialized simulators to create holistic simulation scenarios. In this paper, we present FERAL, our framework for simulator coupling, which enables the integration of simulators with heterogeneous simulation models. We describe the overall coupling approach of FERAL, its simulation model, and its approach for the horizontal and vertical integration of simulation models. We show the applicability of FERAL by a realistic example that demonstrates the potential of simulator coupling for early fault detection.
  • Publication
    Mode-based scheduling with fast mode-signaling - a method for efficient usage of network time slots
    ( 2014) ;
    Gotzhein, Reinhard
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    Today, communication in real-time systems is based on time-triggered or event-triggered protocols, or combinations thereof. Each of these solutions has its benefits and tradeoffs regarding timeliness and bandwidth usage. In this work, we present a new method called mode-based slot scheduling with fast mode-signaling, which can substantially improve bandwidth usage in many scenarios of industrial relevance, while preserving timeliness. With mode-based slot scheduling, a well-controlled amount of dynamic contention for network time slots is possible. Fast mode-signaling is used to reach consensus on the current transmission mode with the highest preference extremely fast and reliably among all network nodes. We present the implementation of our method with TTCAN - a time-triggered protocol in the automotive domain -, and evaluation results.
  • Publication
    D 3.4 Summary report WP3. BRISKEE. Behavioural Response to Investment Risks in Energy Efficiency
    (European Commission, 2017)
    Fries, Benjamin
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    Kreuzer, Martin
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    Braungardt, Sibylle
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    Forthuber, Sebastian
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    Hartner, Michael
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    Kranzl, Lukas
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  • Publication
  • Publication
    Design and Qualification of Pr-Fe-Cu-B Alloys for the Additive Manufacturing of Permanent Magnets
    ( 2021)
    Schäfer, Lukas
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    Skokov, Konstantin
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    Liu, Jianing
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    Maccari, Fernando
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    Riegg, Stefan
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    Radulov, Iliya
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    Merschroth, Holger
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    Harbig, Jana
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    Weigold, Matthias
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    The direct use of an advanced binder-free additive manufacturing technique, namely laser powder bed fusion (L-PBF), does not easily allow obtaining variously shaped, fully dense Nd-Fe-B magnets with high coercivity. The process inherently leads to the re-melting of the powder and appearance/disappearance of undesired/desired microstructural features responsible for low and large coercivity. In this work, the development of a useful microstructure responsible for high coercivity in Pr21Fe73.5Cu2B3.5 and Nd21Fe73.5Cu2B3.5 alloys and a possible way to produce fully dense permanent magnets via additive manufacturing processes is demonstrated using: (i) suction casting technique, which provides a high cooling rate and thus similar microstructures as in L-PBF but requires only very small amounts of powder; (ii) conventional L-PBF processing using kg of powder, and (iii) a subsequent annealing treatment that is similar to a conventional sintering treatment. The subsequent heat treatment is necessary to develop high coercivity by forming a novel microstructure: hard magnetic (Nd,Pr)2Fe14B grains embedded in a matrix of intermetallic (Nd,Pr)6Fe13Cu phase. Furthermore, it is demonstrated that Pr21Fe73.5Cu2B3.5 exhibits a higher coercivity than Nd21Fe73.5Cu2B3.5 because of a finer and more homogeneous grain size distribution of the Pr2Fe14B phase. The final L-PBF printed Pr21Fe73.5Cu2B3.5 samples provide a coercivity of 0.75 T.
  • Publication
    Ausbildungsqualität 4.0 - ein Blick in die Zukunft am Beispiel des Projektes Social Augmented Learning
    ( 2016)
    Fehling, Christian Dominic
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    Goertz, Lutz
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    Hagenhofer, Thomas
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    Die Transformation hin zu einer Industrie 4.0, getragen durch einen bereits im Mainstream wahrgenommenen, ausgesprochen technologischen Entwicklungsschub stellt zahlreiche Berufsfelder vor nicht zu unterschätzende Herausforderungen. Das Berufsfeld Medientechnologin bzw. Medientechnologe Druck, das in diesem Beitrag und bei den Arbeiten im Projekt "Social Augmented Learning" im Mittelpunkt steht, ist davon ebenso stark betroffen wie andere Berufsfelder mit vergleichsweise hohem Anteil an Routinetätigkeiten im Kontext von Automatisierung und der Arbeit an, mit und in Bezug zu Maschinen. Ziel des Projektes war und ist es, nicht nur die technische Infrastruktur für ein effektives und effizientes digitales Lernen mit mobilen Endgeräten und mit Augmented Reality zu ermöglichen, zu definieren und zu beschreiben, sondern zudem in eine kohärente Medienstrategie für Berufsschulen und Ausbildungsbetriebe zu überführen.
  • Publication
    Werker der Zukunft: Assistenz im Zeitalter von Industrie 4.0
    Mit der vierten industriellen Revolution wandelt sich die Produktion. Fertigungsumgebungen werden komplexer und viele Prozesse funktionieren automatisiert. Das erfordert eine nahtlose und flexible Einbindung des Menschen in die digitale Fertigung. Insbesondere in der manuellen Montage führt die steigende Variantenvielfalt zu einer Komplexität, die sich nur noch durch die Unterstützung technischer Assistenzsysteme sicher beherrschen lässt. Der Beitrag stellt die Herausforderungen komplexer manueller Montage- und Wartungsprozesse vor, um darauf aufbauend eine Vision für den Werker der Zukunft zu entwerfen. Diese Vision wird anschließend mit zwei Lösungsansätzen aus der Fraunhofer-Forschung illustriert.