620 Ingenieurwissenschaften und Maschinenbau
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Supply chains have evolved into dynamic, interconnected supply networks, which increases the complexity of achieving end-to-end traceability of object flows and their experienced events. With its capability to ensure a secure, transparent, and immutable environment without relying on a trusted third party, the emerging blockchain technology shows strong potential to enable end-to-end traceability in such complex multitiered supply networks. However, as the dissertation’s systematic literature review reveals, the currently available blockchain-based traceability solutions lack the ability to map object-related supply chain events holistically, which involves mapping objects’ creation and deletion, aggregation and disaggregation, transformation, and transaction. Therefore, this dissertation proposes a novel blockchain-based traceability architecture that integrates governance and token concepts to overcome the limitations of existing architectures. While the governance concept manages the supply chain structure on an application level, the token concept includes all functions to conduct object-related supply chain events. For this to be possible, this dissertation’s token concept introduces token ‘blueprints’, which allow clients to group tokens into different types, where tokens of the same type are non-fungible. Furthermore, blueprints can include minting conditions, which are, for example, necessary when mapping assembly or delivery processes. In addition, the token concept contains logic for reflecting all conducted object-related events in an integrated token history. This ultimately leads to end-to-end traceability of tokens and their physical or abstract representatives on the blockchain. For validation purposes, this dissertation implements the architecture’s components and their update and request relationships in code and proves its applicability based on the Ethereum blockchain. Finally, this dissertation provides a scenario-based evaluation based on two industrial case studies from a manufacturing and logistics perspective to validate the architecture’s capabilities when applied in real-world industrial settings. The proposed blockchain-based traceability architecture thus covers all object-related supply chain events derived from the two industrial case studies and therefore proves its general-purpose end-to-end traceability capabilities of object flows.
After more than three decades of electronic design automation, most layouts for analog integrated circuits are still handcrafted in a laborious manual fashion today. Obverse to the highly automated synthesis tools in the digital domain (coping with the quantitative difficulty of packing more and more components onto a single chip – a desire well known as More Moore), analog layout automation struggles with the many diverse and heavily correlated functional requirements that turn the analog design problem into a More than Moore challenge. Facing this qualitative complexity, seasoned layout engineers rely on their comprehensive expert knowledge to consider all design constraints that uncompromisingly need to be satisfied. This usually involves both formally specified and nonformally communicated pieces of expert knowledge, which entails an explicit and implicit consideration of design constraints, respectively.
Existing automation approaches can be basically divided into optimization algorithms (where constraint consideration occurs explicitly) and procedural generators (where constraints can only be taken into account implicitly). As investigated in this thesis, these two automation strategies follow two fundamentally different paradigms denoted as top-down automation and bottom-up automation. The major trait of top-down automation is that it requires a thorough formalization of the problem to enable a self-intelligent solution finding, whereas a bottom-up automatism –controlled by parameters– merely reproduces solutions that have been preconceived by a layout expert in advance. Since the strengths of one paradigm may compensate the weaknesses of the other, it is assumed that a combination of both paradigms –called bottom-up meets top-down– has much more potential to tackle the analog design problem in its entirety than either optimization-based or generator-based approaches alone.
Against this background, the thesis at hand presents Self-organized Wiring and Arrangement of Responsive Modules (SWARM), an interdisciplinary methodology addressing the design problem with a decentralized multi-agent system. Its basic principle, similar to the roundup of a sheep herd, is to let responsive mobile layout modules (implemented as context-aware procedural generators) interact with each other inside a user-defined layout zone. Each module is allowed to autonomously move, rotate and deform itself, while a supervising control organ successively tightens the layout zone to steer the interaction towards increasingly compact (and constraint compliant) layout arrangements. Considering various principles of self-organization and incorporating ideas from existing decentralized systems, SWARM is able to evoke the phenomenon of emergence: although each module only has a limited viewpoint and selfishly pursues its personal objectives, remarkable overall solutions can emerge on the global scale.
Several examples exhibit this emergent behavior in SWARM, and it is particularly interesting that even optimal solutions can arise from the module interaction. Further examples demonstrate SWARM’s suitability for floorplanning purposes and its application to practical place-and-route problems. The latter illustrates how the interacting modules take care of their respective design requirements implicitly (i.e., bottom-up) while simultaneously paying respect to high level constraints (such as the layout outline imposed top-down by the supervising control organ). Experimental results show that SWARM can outperform optimization algorithms and procedural generators both in terms of layout quality and design productivity. From an academic point of view, SWARM’s grand achievement is to tap fertile virgin soil for future works on novel bottom-up meets top-down automatisms. These may one day be the key to close the automation gap in analog layout design.
Saving energy and protecting the environment became fundamental for society and politics, why several laws were enacted to increase the energy-efficiency. Furthermore, the growing number of vehicles and drivers leaded to more accidents and fatalities on the roads, why road safety became an important factor as well. Due to the increasing importance of energy-efficiency and safety, car manufacturers started to optimise the vehicle in terms of energy-effciency and safety. However, energy-efficiency and road safety can be also increased by adapting the driving behaviour to the given driving situation. This thesis presents a concept of an adaptive and rule based driving system that tries to educate the driver in energy-efficient and safe driving by showing recommendations on time. Unlike existing driving-systems, the presented driving system considers energy-efficiency and safety relevant driving rules, the individual driving behaviour and the driver condition. This allows to avoid the distraction of the driver and to increase the acceptance of the driving system, while improving the driving behaviour in terms of energy-efficiency and safety. A prototype of the driving system was developed and evaluated. The evaluation was done on a driving simulator using 42 test drivers, who tested the effect of the driving system on the driving behaviour and the effect of the adaptiveness of the driving system on the user acceptance. It has been proven during the evaluation that the energy-efficiency and safety can be increased, when the driving system was used. Furthermore, it has been proven that the user acceptance of the driving system increases when the adaptive feature was turned on. A high user acceptance of the driving system allows a steady usage of the driving system and, thus, a steady improvement of the driving behaviour in terms of energy-efficiency and safety.
Beschleunigung und Reorientierung des technischen Fortschritts überfordern selbst große Unternehmen im Spannungsfeld zwischen Spezialisierung und interdisziplinärer Konvergenz. So wird die Kombination interner Forschung und Entwicklung mit externem Wissen, vor allem in Hochtechnologien, zur zentralen Voraussetzung langfristigen Unternehmenserfolgs. In diesem Kontext untersucht die vorliegende Dissertation das Potenzial kooperativen Verhaltens zwischen Unternehmen zur Bewältigung technologischer Diskontinuitäten am Beispiel des bevorstehenden Paradigmenwechsels im automobilen Antrieb. Dabei wird Kooperation als superiore Strategie zur Stimulation des explorativen Innovationsmodus identifiziert und in eine übergreifende Dynamik der Koordinationseignung im Verlauf technologischen Fortschritts integriert. Bezogen auf den automobilen Antrieb ist eine nachhaltigkeitsinduzierte Destabilisierung des technologischen Paradigmas des Verbrennungsmotors festzustellen, während sich seine intensiven Möglichkeiten erschöpfen. Konsequenz dessen ist zunehmender Innovationsdruck, der konsistenzorientiert eine systemische Transformation von Kraftwerkstechnik und Energienetz sowie einen Paradigmenwechsel zu elektrischen Antrieben erzwingt. Aufgrund der bisher geringen technologischen Reife und hohen Kosten elektrischer Antriebssysteme zeichnet sich allerdings ein Übergang in Form einer graduellen Rekonfiguration über eine Hybridphase ab, deren Dynamik maßgeblich von der Entwicklung der technoökonomischen Schlüsselmodule Batterie und Brennstoffzelle abhängt. Die dazu erforderliche technologische Transformation birgt existenzielle Gefährdungen für die etablierten Unternehmen der Automobilindustrie, die sich gegenüber ihren Herausforderern explorationsbezogen in einer inferioren Ausgangssituation befinden. Eben hier bieten sich umfangreiche Potenziale kooperativer Exploration elektrischer Antriebe auf Verhaltens-, Innovationsprozess und Wissensebene. In Relation zu diesen erscheint das reale Kooperationsniveau jedoch als gering, volatil und, vor allem in Deutschland, übermäßig intrasektoral fokussiert.
Aus diesen Erkenntnissen ergeben sich Implikationen für Unternehmensführung, Innovationspolitik und Forschung. Managementseitig besteht die zentrale Herausforderung in der Befähigung der Organisation zu Dynamisierung von Wissen und Fähigkeiten durch simultan-heterogene Koordination explorativer und exploitativer Innovationsströme. Insbesondere die Erschließung kooperativer Potenziale setzt allerdings die Bereitschaft zur Einschränkung der eigenen Unabhängigkeit sowie zur Abweichung von bewährten Verhaltensmustern voraus. Innovationspolitisch steht die Überwindung von Beharrungskräften durch Anpassung des sozio-institutionellen Rahmens sowie die Förderung langfristiger Kooperation bei potenzialgeleiteter Intersektorialität im Vordergrund. Forschungsbezogen eröffnet speziell die Kombination von Innovations- Nachhaltigkeits- und Koordinationstheorie ein besseres Verständnis von Triebfedern und Dynamik technischen Fortschritts, das weiter vertieft werden sollte.
Compared to diesel or gasoline, using compressed natural gas as a fuel allows for significantly decreased carbon dioxide emissions. With the benefits of this technology fully exploited, substantial increases of engine efficiency can be expected in the near future. However, this will lead to exhaust gas temperatures well below the range required for the catalytic removal of residual methane, which is a strong greenhouse gas. By combination with a countercurrent heat exchanger, the temperature level of the catalyst can be raised significantly in order to achieve sufficient levels of methane conversion with minimal additional fuel penalty. This thesis provides fundamental theoretical background of these so-called heat-integrated exhaust purification systems. On this basis, prototype heat exchangers and appropriate operating strategies for highly dynamic operation in passenger cars are developed and evaluated.