Hochschule Bonn-Rhein-Sieg
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Work in Progress: Implementing and Evaluating a Competency-Oriented Assessment in an Innovative Application-Oriented Course of Mechanical Engineering
No full textJournalistische Berichterstattung über technische Innovation – eine qualitative Untersuchung der Medienwirkung anhand des Motocross-Motorrades Stark VARG
No full textIntegrated solar hydrogen production: Impact of the local climate
No full textHydrogen as a versatile, greenhouse gas-free energy carrier will play an important role in our future economy. Yet sustainable, competitive production and distribution of hydrogen remains a challenge. Highly integrated solar water splitting systems aim to combine solar energy harvesting and electrolysis in a single device, similar to a photovoltaic module.[1] Such a system can produce hydrogen locally without the requirement to be connected to the electricity grid. Unlike large electrolysis that draws power from the grid, the power density of such a device is reduced so far that it does not require active cooling, but its operating temperature will closely follow outdoor conditions.
Here, we present our work on high-efficiency integrated solar water splitting devices based on multi-junction solar absorbers. The light-absorbing component is sensitive to the shape of the solar spectrum and generally becomes more efficient at lower temperatures. Catalysis, on the other hand, benefits from higher temperatures. These conflicting trends wih respect to the temperature impact the design of the solar hydrogen production system. We analyse how the local climate affects production efficiency[2] and show in a lab study that adequate system design allows efficient operation at temperatures as low as -20°C.[3] These insights can help to design small-scale distributed solar hydrogen production for both temperate regions, but also more extreme climatic conditions
Grundkurs Geschäftsprozess-Management: Analyse, Modellierung, Optimierung und Controlling von Prozessen
No full textDieses Lehrbuch schlägt die Brücke zwischen den betriebswirtschaftlich-organisatorischen Methoden und deren digitaler Umsetzung, denn Prozessmanagement heißt zunehmend Gestaltung betrieblicher Aufgaben. Neben methodischen Grundlagen bietet das Werk viele Praxisbeispiele und Übungen. Das Buch von Prof. Gadatsch gilt mittlerweile als der "aktuelle Klassiker", DAS maßgebliche Standardwerk zur IT-gestützten Gestaltung von Geschäftsprozessen. (Verlagsangaben
Efficient Quality Diversity Optimization of 3D Buildings through 2D Pre-optimization
No full textQuality diversity algorithms can be used to efficiently create a diverse set of solutions to inform engineers' intuition. But quality diversity is not efficient in very expensive problems, needing 100.000s of evaluations. Even with the assistance of surrogate models, quality diversity needs 100s or even 1000s of evaluations, which can make it use infeasible. In this study we try to tackle this problem by using a pre-optimization strategy on a lower-dimensional optimization problem and then map the solutions to a higher-dimensional case. For a use case to design buildings that minimize wind nuisance, we show that we can predict flow features around 3D buildings from 2D flow features around building footprints. For a diverse set of building designs, by sampling the space of 2D footprints with a quality diversity algorithm, a predictive model can be trained that is more accurate than when trained on a set of footprints that were selected with a space-filling algorithm like the Sobol sequence. Simulating only 16 buildings in 3D, a set of 1024 building designs with low predicted wind nuisance is created. We show that we can produce better machine learning models by producing training data with quality diversity instead of using common sampling techniques. The method can bootstrap generative design in a computationally expensive 3D domain and allow engineers to sweep the design space, understanding wind nuisance in early design phases
Skill generalisation and experience acquisition for predicting and avoiding execution failures
No full textFor performing tasks in their target environments, autonomous robots usually execute and combine skills. Robot skills in general and learning-based skills in particular are usually designed so that flexible skill acquisition is possible, but without an explicit consideration of execution failures, the impact that failure analysis can have on the skill learning process, or the benefits of introspection for effective coexistence with humans. Particularly in human-centered environments, the ability to understand, explain, and appropriately react to failures can affect a robot's trustworthiness and, consequently, its overall acceptability. Thus, in this dissertation, we study the questions of how parameterised skills can be designed so that execution-level decisions are associated with semantic knowledge about the execution process, and how such knowledge can be utilised for avoiding and analysing execution failures. The first major segment of this work is dedicated to developing a representation for skill parameterisation whose objective is to improve the transparency of the skill parameterisation process and enable a semantic analysis of execution failures. We particularly develop a hybrid learning-based representation for parameterising skills, called an execution model, which combines qualitative success preconditions with a function that maps parameters to predicted execution success. The second major part of this work focuses on applications of the execution model representation to address different types of execution failures. We first present a diagnosis algorithm that, given parameters that have resulted in a failure, finds a failure hypothesis by searching for violations of the qualitative model, as well as an experience correction algorithm that uses the found hypothesis to identify parameters that are likely to correct the failure. Furthermore, we present an extension of execution models that allows multiple qualitative execution contexts to be considered so that context-specific execution failures can be avoided. Finally, to enable the avoidance of model generalisation failures, we propose an adaptive ontology-assisted strategy for execution model generalisation between object categories that aims to combine the benefits of model-based and data-driven methods; for this, information about category similarities as encoded in an ontology is integrated with outcomes of model generalisation attempts performed by a robot. The proposed methods are exemplified in terms of various use cases - object and handle grasping, object stowing, pulling, and hand-over - and evaluated in multiple experiments performed with a physical robot. The main contributions of this work include a formalisation of the skill parameterisation problem by considering execution failures as an integral part of the skill design and learning process, a demonstration of how a hybrid representation for parameterising skills can contribute towards improving the introspective properties of robot skills, as well as an extensive evaluation of the proposed methods in various experiments. We believe that this work constitutes a small first step towards more failure-aware robots that are suitable to be used in human-centered environments
#datendienstag: Datenmanagementpläne und Forschungsdatenmanagement in Forschungsanträgen
No full textDie Projektverbünde in der Förderlinie FDMScouts.nrw haben am 28.03.2023 die Online-Veranstaltung "#datendienstag: Datenmanagementpläne und Forschungsdatenmanagement in Forschungsanträgen" angeboten. Der Vortrag richtete sich an Forschende und Infrastrukturangehörige – vor allem aus der Forschungsförderung, welche die Antragsstellung begleiten.
Viele Drittmittelgeber erwarten als Teil eines Förderantrags Informationen zum Umgang mit Forschungsdaten. Ein formeller Datenmanagementplan (DMP) wird nur in den seltensten Fällen verlangt. Dennoch ist ein DMP für die Arbeit in einem Forschungsprojekt von Vorteil. Welche Vorteile dies sind und welche Anforderungen Forschende bei der Antragstellung bezüglich des FDMs zu erwarten haben, waren – neben Tipps und Tricks – Gegenstand dieser Veranstaltung
