openHSU – Research Showcase
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- PublicationOpen AccessSignalverarbeitung für Tunnel-Magnetoresistive Sensor-Arrays(UB HSU, 2024-11-29)Deutsch: In mechatronischen Anwendungen sind magnetoresistive Sensoren weit verbreitet. Sie gelten unter rauen Umgebungsbedingungen als besonders robust, da sie die Messgröße berührungslos erfassen. Heute werden diese Sensoren zum Beispiel für die Winkelmessung in Elektromotoren oder in der Servolenkung eingesetzt. In der vorliegenden Dissertation wird eine neue Sensortechnologie auf der Basis des Tunnel-Magnetoresistiven Effekts (TMR) mit dem Konzept der Sensor-Arrays kombiniert. Dabei erlaubt die TMR-Technologie erstmals eine effiziente Integration des Arrays als Sensor-Chip. Die Verteilung auf viele Messpunkte im Array ermöglicht die ortsaufgelöste Messung von Magnetfeldern und unterscheidet sich damit von bisherigen Konzepten. Das Ausgangsverhalten von ausgewählten TMR-Sensoren wird in einem spezialisierten Messplatz charakterisiert und in Kennfeldern zusammengefasst. Dabei wird gezeigt, welche Eigenschaften von TMR-Sensoren besondere Vorteile für ein Array liefern. Anschließend werden Signalverarbeitungsmethoden für magnetoresistive Sensor-Arrays entwickelt. Der hohe Informationsgehalt der Array-Struktur erlaubt die Berücksichtigung der Selbstdiagnose-Funktionalität, Reduktion externer magnetischer Störeinflüsse und Erhöhung von Toleranzbereichen. Die Funktionsweise der Methoden wird mit Hardware-Aufbauten des Sensor-Arrays und auswertender Signalverarbeitungs-Software demonstriert. Dazu werden drei Anwendungsbeispiele untersucht. Zwei Anwendungsbeispiele sind im Bereich der Mechatronik einzuordnen und haben eine hochgenaue Winkelmessung zum Ziel. Die dritte Anwendung aus der Medizintechnik untersucht die dreidimensionale Ortung eines Magneten.
- PublicationOpen AccessTowards optimal operation of large-scale electric bus depots(UB HSU, 2024-11-22)The shift towards a climate-neutral future is driving the electrification of transportation, particularly through the adoption of electric bus fleets worldwide. While this transition presents infrastructural, financial, and operational challenges, it also creates opportunities for innovative solutions, such as participation in energy markets and the provision of ancillary services. To effectively navigate these challenges and opportunities, the Bus Depot Simulator (BDS) was developed to simulate electric bus depot operations and analyze load flow within the electrical infrastructure. Empirical models of electric buses, based on field data, were integrated into the BDS, which focused on 17 bus depots in Hamburg, Germany. This analysis identified three clusters of depots based on their load profiles. Additionally, the impact of ambient temperature, day of the week, and charging power on the load profile was investigated. This information can assist fleet and grid operators in analyzing, operating, and optimizing electric power systems. Furthermore, algorithms for intelligent route and charging scheduling were created to minimize the costs of electric bus fleets and reduce the resulting load peak at the bus depots. Finally, a new method was proposed to quantify the power flexibility of electric buses, providing valuable insights for fleet operators and market participants in developing future use cases.
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- PublicationOpen AccessZielorientierte und nutzenzentrierte Entwicklung und Implementierung von Digital Twins in Fertigungsunternehmen(UB HSU, 2024-11-19)Deutsch: In der modernen industriellen Fertigung lässt sich trotz hoher Stückzahlen eine zunehmende Individualisierung der Produkte beobachten. Die Digitalisierung, insbesondere im Kontext von Industrie 4.0 und 5.0, bietet großes Potenzial, diesen Trend zu beschleunigen und Marktbedürfnisse zielgerichteter zu befriedigen. Digital Twins (DTs) spielen dabei eine zentrale Rolle, indem sie Transparenz schaffen und zuvor isolierte Unternehmensbereiche verknüpfen. Trotz intensiver Forschungsbemühungen weisen DT-Projekte in der Industrie im Jahr 2024 noch einen geringen Reifegrad auf. Diese Dissertation untersucht anhand umfangreicher empirischer Studien die Gründe für den niedrigen Reifegrad von DTs in Fertigungsunternehmen und identifiziert dabei technische, organisatorische und methodische Herausforderungen. Der Fokus liegt besonders auf organisatorischen und methodischen Faktoren wie der Kostenbewertung, der Benutzerakzeptanz und der Zielsetzung, die zentrale Hürden darstellen. Zur Bewältigung dieser Handlungsfelder wurde ein neuartiges Framework entwickelt, das die Entwicklung und Implementierung von DTs systematisiert und die Erfolgsaussichten solcher Projekte erhöht. Das Kober Digital Twin Framework (KDTF) umfasst fünf neu entwickelte Modelle: 1. Digital Twin Stakeholder Communication Model (DT-SCM): Ein ganzheitliches Modell, das die Kommunikation zwischen den Stakeholdern durch eindeutig definierte Dimensionen verbessert. 2. Digital Twin Fidelity Requirements Model (DT-FRM): Ein strukturiertes Modell zur präzisen Zielsetzung und Priorisierung von Einflussfaktoren. 3. Digital Twin Benefit Curves (DT-BC): Grafische Darstellungen der Beziehung zwischen DT-Fidelity, Mehrkosten und Einsparpotenzialen. 4. Digital Twin Fidelity Calculation Model (DT-FCM): Ein methodischer Ansatz zur Berechnung der optimalen DT-Fidelity. 5. Digital Twin Cost-Benefit Framework (DT-CBF): Ein systematisches Modell zur Identifizierung und Bewertung der Potenziale und Kosten von DTs. Es wurde mithilfe der Design Science Research (DSR) Methodik entwickelt und validiert, welche eine flexible, iterative Entwicklung und kontinuierliche Verbesserung ermöglichte. Die übergeordnete Validierung des gesamten Frameworks erfolgte anhand eines fortschrittlichen Fallbeispiels aus der industriellen Praxis eines innovativen Sägewerks. Es wurde deutlich, dass das Framework die Entwicklung und Implementierung wirtschaftlich erfolgreicher und technisch komplexer DTs ermöglicht. Fertigungsunternehmen werden dabei unterstützt, ein optimales Kosten-Nutzen-Verhältnis bei der Entwicklung und Implementierung von DTs zu realisieren und informierte Entscheidungen der verantwortlichen Stakeholder zu fördern. Abschließend stellt das in dieser Dissertation entwickelte Framework eine wesentliche Innovation dar, die sowohl wissenschaftlich fundiert ist als auch praktische Anwendung findet. Es trägt dazu bei, die Verbreitung von DTs in der Fertigung zu fördern und sichert somit die nachhaltige Relevanz dieses Forschungsfeldes.
- PublicationOpen AccessGerman strategy on China - a critical appraisal(German Association for Asian Studies, 2024-11-11)In this article, I critically examine the German Strategy on China as a central policy paper for self-assurance in its China policy. The strategy resolves the ambivalence of previous China policies through the multidimensional triad of “partner, competitor, and systemic rival” and points the way toward a new, sober realpolitik.
- PublicationMetadata onlyUnraveling the contribution of serotonergic polymorphisms, prefrontal alpha asymmetry, and individual alpha peak frequency to the emotion-related impulsivity endophenotype(Humana Press ; Springer, 2022-07-19)The unique contribution of the serotonin transporter-linked polymorphic region (5-HTTLPR), intronic region 2 (STin2), and monoamine oxidase A (MAO-A) genes to individual differences in personality traits has been widely explored, and research has shown that certain forms of these polymorphisms relate to impulsivity and impulsivity-related disorders. Humans showing these traits are also described as having an asymmetrical prefrontal cortical activity when compared to others. In this explorative study, we examine the relationship between serotonergic neurotransmission polymorphisms, cortical activity features (prefrontal alpha asymmetry, individual alpha peak frequency [iAPF]), emotion-related and non-emotion-related impulsivity in humans. 5-HTTLPR, MAO-A, and STin2 polymorphisms were assessed in blood taken from 91 participants with high emotion-related impulsivity levels. Sixty-seven participants completed resting electroencephalography and a more comprehensive impulsivity index. In univariate analyses, iAPF correlated with both forms of emotion-related impulsivity. In multiple linear regression models, 5-HTTLPR polymorphism (model 1, adj. R 2 = 15.2%) and iAPF were significant interacting predictors of emotion-related impulsivity, explaining a large share of the results’ variance (model 2, adj. R 2 = 21.2%). Carriers of the low transcriptional activity 5-HTTPLR and MAO-A phenotypes obtained higher emotion-related impulsivity scores than others did. No significant results were detected for non-emotion-related impulsivity or for a form of emotion-related impulsivity involving cognitive/motivational reactivity to emotion. Our findings support an endophenotypic approach to impulsivity, showing that tri-allelic 5-HTTLPR polymorphism, iAPF, and their interaction are relevant predictors of one form of emotion-related impulsivity.
- PublicationMetadata onlyWord class and word frequency in the MMN looking glass(Elsevier, 2021-05-05)The effects of lexical meaning and lexical familiarity on auditory deviance detection were investigated by presenting oddball sequences of words, while participants ignored the stimuli. Stimulus sequences were composed of words that were varied in word class (nouns vs. functions words) and frequency of language use (high vs. low frequency) in a factorial design with the roles of frequently presented stimuli (Standards) and infrequently presented ones (Deviants) were fully crossed. Deviants elicited the Mismatch Negativity component of the event-related brain potential. Modulating effects of lexical meaning were obtained, revealing processing advantages for denotationally meaningful items. However, no effect of word frequency was observed. These results demonstrate that an apparently low-level function, such as auditory deviance detection utilizes information from the mental lexicon even for task-irrelevant stimuli.
- PublicationMetadata onlyDoes self-reported chronic pain influence savoring of aesthetic experiences?(PLOS, 2021-11-12)Background: Aesthetic experiences elicit a wide range of positive emotions and have a positive impact on various health outcomes. In this context, savoring refers to a cognitive form of emotion regulation used to maintain and extend positive emotional experiences and is considered to contribute to health and well-being. Chronic pain has been linked to reduced reward-seeking behavior. This is the first study to investigate the relationship between self-reported chronic pain and savoring. Methods: We conducted an anonymous cross-sectional survey in a large non-clinical sample (opera, theater, and cabaret visitors; n = 322). The variables were assessed with a two-item-questionnaire. Results: Self-reported chronic pain was significantly negatively correlated with savoring (r = -.547) Conclusion: Altogether, this result helps to develop a better understanding of the effects of chronic pain in humans and to shed light on state-dependent differences in aesthetic experiences.
- PublicationMetadata only"I'm getting too old for this stuff"(Elsevier, 2021-08-12)While body modifications have increasingly gained acceptance and popularity, how different subpopulations aesthetically appreciate tattoos remains unclear. The present study aimed to investigate the conceptual structure underlying tattoo aesthetics, focusing on the effects of internalized social norms and expertise. Using a timed free-listing task, three groups (≤49 years, ≥50 years, and experts) comprising 497 participants were asked to write down adjectives that could describe tattoo aesthetics. Statistical analyses of frequency, cognitive salience indices, co-occurrence dimensions, semantic dimensions, similarity measures, and valences were applied and, to directly compare the three groups, a generalized Procrustes analysis was applied. The variance and complexity with which individuals verbally expressed their perceived aesthetic appeal of tattoos were highlighted. However, the results do not reveal a unified concept of beauty, nor do they present a clear bipolar dimension of beautiful/ugly for two of the three groups. Nevertheless, the concept of beauty was found to be prominent in tattoo aesthetics, and aesthetic and descriptive–evaluative dimensions were identified, with terms such as beautiful, ugly, multicolored, and interesting being the most notable adjectives, although not with the highest valence. Possible factors explaining the intracultural differences between the three groups are also discussed.
- PublicationMetadata onlyWhen personality gets under the skin(PLOS, 2021-03-03)Do individuals modify their bodies in order to be unique? The present study sought to investigate need for uniqueness (NfU) subcomponents as possible motives for modifying one’s body. To this end, the study obtained information from 312 participants about their NfU (using the German NfU-G global scale and three sub-scales) and their body modifications (tattoos, piercings, and extreme body modifications such as tongue splitting). By analyzing the three subcomponents of NfU, the study was able to investigate the differential relationship of the sub-scales with the outcome measures, which facilitated a fine-grained understanding of the NfU–body-modification relationship. The study found that tattooed, pierced, and extreme-body-modified individuals had higher NfU-G scores than individuals without body modifications. Moreover, it seemed that individuals with tattoos took a social component into consideration while lacking concern regarding others’ reaction toward their tattoos, although not wanting to cause affront. Pierced and extreme-body-modified individuals, contrarily, tended to display a propensity to actively flout rules and not worry about others’ opinions on their modifications. However, although statistically significant, the effect size ( d ) for the NfU-G differences in the tattooed and pierced participants’ mean scores was small to medium in all three subcomponents. The extreme-body-modified group presented medium and medium to large effects. Further, the study observed that the number of body modifications increased with an increasing NfU in tattooed and pierced individuals. These findings demonstrated multifaceted interrelations between the NfU, its subcomponents, and the three kinds of body modifications investigated in the present study.