Publikationsserver der Ostbayerischen Technischen Hochschule Regensburg
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IT/OT Convergence: Status Quo and Implementation Recommendations
No full textThis study examines IT/OT Convergence in 31 predominantly large German companies. It presents an "IT/OT Governance Framework" as a specific model for successful convergence implementation. The in-terviews revealed that companies are at very different stages of maturity in implementing IT/OT conver-gence. The analysis reveals a heterogeneous level of convergence maturity across the interviewed compa-nies, the majority of which are at the beginning or in the implementation phase. Close cooperation between IT and OT is favoured, but without IT completely taking over OT. An IT/OT tandem consisting of a CIO and a central OT responsible person is seen as the ideal way to take responsibility. Six specific recommen-dations were derived from the interviews and included in the IT/OT Governance Framework developed. These include ensuring top management support, using security as a driver, introducing a central OT re-sponsible person, bringing IT and OT teams closer together, continuously demonstrating the added value of convergence, and taking a step-by-step approach to implementatio
19 Import options for green hydrogen and derivatives - An overview of efficiencies and technology readiness levels
No full textThe import of hydrogen and derivatives forms part of many national strategies and is fundamental to achieving climate protection targets. This paper provides an overview and technical comparison of import pathways for hydrogen and derivatives in terms of efficiency, technological maturity and development and construction times with a focus on the period up to 2030. The import of hydrogen via pipeline has the highest system efficiency at 57-67 % and the highest technological maturity with a technology readiness level (TRL) of 8-9. The import of ammonia and methanol via ship and of SNG via pipeline shows efficiencies in the range of 39-64 % and a technological maturity of TRL 7 to 9 when using point sources. Liquid hydrogen, LOHC and Fischer-Tropsch products have the lowest efficiency and TRL in comparison. The use of direct air capture (DAC) reduces efficiency and TRL considerably. Reconversion of the derivatives to hydrogen is also associated with high losses and is not achievable for all technologies on an industrial scale up to 2030. In the short to medium term, import routes for derivatives that can utilise existing infrastructures and mature technologies are the most promising for imports. In the long term, the most promising option is hydrogen via pipelines
Persistence of Questionnaire Data on Learning Styles, Learning Strategies AND Personality Traits
No full textIn the context of learning, questionnaires are carried out to gain information about learners. This learner profile has various benefits, like adapting the learning content, promoting of self-reflection, or increasing motivation in learning and therefore better learning results. Some researchers take the results of such questionnaires as ground truth or trust them blindly. Examining how persistent questionnaires are, asking the same questions twice, and comparing the results is a way to prove or falsify this statement.
Our research procedure compares the results of three different questionnaires. The first questionnaire is the ILS (index of learning styles) according to the Felder-Silverman Learning Style Model (FSLSM) with about 44 questions. Learning strategies are examined with the LIST-K questionnaire consisting of 39 questions after Klingsieck. The third and last questionnaire is about personality traits. With only ten questions, Rammstedt et al. describe the BFI-10 questionnaire for personality traits. To compare results, the same study with the three named questionnaires is carried out twice with three to four months in between. The sample includes 35 students in their bachelor studies taking the course Software Engineering in a blended learning format. After collecting the questionnaire data from the students, a comparison is made in two different ways. First, we compare the data points based on the given answers. Second, a comparison is made based on the calculated questionnaire results because each of the three questionnaires has its own analysis method. For example, the analysis method of the ILS delivers as a result four integers representing the four characteristics of a learning style, while LIST-K makes a factor analysis. The results of the paper show that both the given answers and the calculated questionnaire results differ. Not one student has given the same answer inside each questionnaire with causes, like a change of learning style, learning strategy, and personality traits, or not filling in conscientiously
Hemocompatibility of Membrane Lung Components from Extracorporeal Membrane Oxygenation with Different Antithrombogenic Coatings
No full textThrombus formation within extracorporeal membrane oxygenation (ECMO) devices remained a critical complication. One reason seems to be the contact of blood with large artificial surfaces within the membrane lung (ML). The aim was to test the hemocompatibility of different naïve ECMO materials. Blood and platelets from five healthy volunteers were incubated with gas exchange (GF) and heat exchange fibers (HE) from four different commercial available new MLs representing different antithrombogenic coatings. Adherent platelets were stained with rhodamine-phalloidin. Surface coverage was quantified with ImageJ. Non-adherent platelets were stained with antibodies (CD62P, PAC-1, CD61) and fibrinogen to detect platelet activation with flow cytometry. Hemolysis of red blood cells after material contact was detected. All ECMO-materials were non-hemolytic and did not induce platelet activation. However, platetelet adhesion (median (IQR)) was significantly elevated on uncoated GFs made of polymethylpentene (GF-PMP; 12 (7-19)%) and on GFs from the Hilite-MLs (GF-Hilite; 13 ((8-19)%) compared to the other materials. In vitro testing of platelet adhesion disclosed significant differences of ECMO-materials with different antithrombogenic surface coatings. Instead, circulating platelets remained non-activated. ECMO-materials and its coatings were non-hemolytic. Finally, this study confirmed the good hemocompatibility of GFs and HEs from commerciall available MLs
Development of Robotics for Building Exterior Inspection: A Literature Review
No full textThe aging of buildings is a global concern, with potential risks to human safety and property. Building inspection and maintenance are crucial for ensuring structural integrity and safety. However, traditional manual methods are time-consuming and pose safety risks, especially for exterior inspection at height. Robotics offer a promising alternative to enhance building inspection efficiency and cost-
effectiveness, but still in the early development stage. This paper aims to review and analyze the state-of-the-art design and development of robotics for building exterior inspection, referring to the literature published in the last two decades. Firstly, the review classifies different types of robots for building exterior inspection in terms of locomotion and adhesion modes, and discusses the capability of robots from navigation, obstacle surmounting, wall-to-wall/floor transition, curved wall climbing, grasping, barrier avoidance, and self-protection. Secondly, the paper examines the applicability of robots to various building materials for inspections and summarizes the most typical applications (i.e. glass curtain walls, tile walls, and concrete walls). Thirdly, the paper discusses the typical data collection and analysis methods for building exterior inspection using robots. The paper also explored potential enhancements for robotic inspection through the
integration of building information modeling, augmented reality/virtual reality, and the involvement of human-in-the-loop. Finally, the paper
summarizes the typical application of robotics in building exterior inspection regarding robot types, inspection applications, data collection and analysis methods, discusses the challenges, and outlines the future directions
Probabilistic Machine Learning for Simulating Complex Learner Profiles
No full textData is the foundation of all machine learning applications. In education science, especially for the learner characteristics that drive personalized learning, it is difficult to collect and often uncertain. It is challenging to model, train, evaluate, and analyze the underlying algorithms when developing AI-based systems and having small sample sizes. To address these problems, we present a synthetic data generator utilising probabilistic models. This generator can effectively model and simulate complex learner profiles. To achieve this, we collected extensive data on learning styles, learning strategies, personalities, and preferred learning paths from 593 students over several semesters at a higher education level. Then, Bayesian networks, Hidden Markov Models, and Markov Chains are used to model the relationships between learner profiles. Using the Bayesian information criterion, and cross-validation with log-likelihood scores, we compare various models to select the best fitting one for synthesizing the data. The synthetic data is then evaluated using statistical validation techniques. In addition, we developed a simulation module with the option to simulate learner profiles based on manual user-defined inputs. The data and code used in this work are available as open source1110.5281/zenodo.13768136 [Titel anhand dieser DOI in Citavi-Projekt übernehmen] contributing to open science and developers for customized simulated data. In the future, this data will refine the training, evaluation, analysis, and benchmarking of algorithms for personalized learning
Measurement of field emission array current distributions by metal-coated CMOS image sensors
No full textA CMOS image sensor is utilized to determine the time- and spatially resolved distribution of the total electron emission current of a silicon field emission array. The sensor measures electron emission without the need for phosphorus screens or scintillators as converters. However, in initial experiments, rather low field emission currents of several hundreds of nanoamperes per emitter already damaged the sensor surface, which altered the systems’ signal response over the measurement time. In consequence, we coated the CMOS sensor surface with a Cu layer for surface protection. In contrast to the original insulating surface, Cu is an excellent current- and heat-conductor, which avoids lens charging by providing a conductive path for incident electrons and has an improved heat dissipation capability. Measurements using a segmented field emission cathode with four individually addressable tips demonstrate a consistent correlation between the emission current and the sensor signal of the metal-coated image sensor. Furthermore, the characterization of a field emission array showed that single tip emission currents of up to 12 μA per tip are measurable without discernible damage effects of the sensor’s surface
It's Quick to be Square: Fast Quadratisation for Quantum Toolchains
No full textMany of the envisioned use-cases for quantum computers involve optimisation processes. While there are many algorithmic primitives to perform the required calculations, all eventually lead to quantum gates operating on quantum bits, with an order as determined by the structure of the objective function and the properties of target hardware. When the structure of the problem representation is not aligned with structure and boundary conditions of the executing hardware, various overheads degrading the computation may arise, possibly negating any possible quantum advantage. Therefore, automatic transformations of problem representations play an important role in quantum computing when descriptions (semi-)targeted at humans must be cast into forms that can be executed on quantum computers. Mathematically equivalent formulations are known to result in substantially different non-functional properties depending on hardware, algorithm and detail properties of the problem. Given the current state of noisy intermediate-scale quantum (NISQ) hardware, these effects are considerably more pronounced than in classical computing. Likewise, efficiency of the transformation itself is relevant because possible quantum advantage may easily be eradicated by the overhead of transforming between representations. In this paper, we consider a specific class of higher-level representations, i.e. polynomial unconstrained binary optimisation problems, and devise novel automatic transformation mechanisms into widely used quadratic unconstrained binary optimisation problems that substantially improve efficiency and versatility over the state of the art. We also identify what influence factors of lower-level details can be abstracted away in the transformation process, and which details must be made available to higher-level abstractions
Double-Beam Cantilever Probe for Crack Probability Analysis of Multilayer Substrates During Wafer Probing
No full textDuring wafer testing, small probes are contacting pads on the wafer surface to check the chip functionality and identify faulty dies. To prevent damaging structures underneath, a mechanical load limit needs to be defined. This is done by intentionally overstressing the pads and searching for cracks that appear. A customized test bench with a patented sensor-indenter (SI) system is currently used to perform the contact cycles and identify crack formations in real time using the generated acoustic emissions (AEs). This method is faster and more accurate compared with previous optical detection methods. This article presents an improved version of the SI system usable in a wafer prober, featuring a double-beam cantilever beam with an exchangeable indenter tip. This leads to measurement conditions closer to productive wafer testing, enabling more accurate load limit definitions. The cantilever beam contains a strain gauge Wheatstone bridge for contact force measurement and a piezoelectric sensor element for AE signal detection. Amplifier circuits are designed for both sensors, and a data acquisition (DAQ) system is developed. A prototype of the sensor cantilever combination (SCC) is shown together with simulated and experimental results. The accuracy of the force sensor ( ±0.5 → ±1.3 mN) and the signal-to-noise ratios (SNRs) of the AE signals ( 29.1 → 21 dB) show only a small decrease compared with the previous SI system. A crack probability analysis of a test specimen confirms the usability of the SCC, as AE crack signals are detected at a similar mechanical load with both sensor setups