Publikationsserver der Ostbayerischen Technischen Hochschule Regensburg
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Assessing the impact of bifacial solar photovoltaics on future power systems based on capacity-density-optimised power plant yield modelling
No full textBifacial solar photovoltaic (PV) technology is currently taking over the solar PV module market, exceeding a 90% share in 2025. This important technology must be included in energy system modelling. This study provides a method for calculating the yield of monofacial and bifacial power plants in fixed-tilted, single-axis tracking, and east-west facing vertical setup. A novel method is introduced to maximise the capacity density of solar PV power plants without the need for detailed land cost for the most efficient use of the occupied area. The results indicate a 15-20% yield gain from single-axis tracking compared to fixed-tilted power plants, and a limited bifacial gain of up to 10% for most areas of the world. Higher bifacial gains are sporadically possible in specific conditions. Fixed-tilted systems show higher bifacial gains. Optimising tilt angles and row pitch would allow for 147 MW/ km2 capacity density today, though on average 70-110 MW/km2 can be achieved for 20.2% module efficiency. The impact on the power system, studied in a free cost optimisation scenario and forcing vertical bifacial PV scenario, implying agrivoltaics, is not significant with a +/- 10% change in total solar PV capacity, change in installed wind power of on average-10%, increase of installed battery capacity of on average 5%, and an on average changed levelised cost of electricity of-2% globally. Bifacial solar PV technology has been found to be beneficial but no game changer for future power systems; system improvements are widely possible underlining the important role of this technology
„…dieser verbissene und humorlose Hühnerhaufen…“ - Sexismus und Antifeminismus in der Politik
No full textDas Versprechen der Demokratie – die gleichberechtigte Partizipation aller – scheint in Bezug auf Geschlecht umgesetzt zu sein, zumindest im Hinblick auf das Wahlrecht. Trotzdem sind Frauen seltener in deutschen Parlamenten vertreten und Politikerinnen sind zudem vielfältigen Anfeindungen und Herabwürdigungen aufgrund ihres Geschlechts ausgesetzt. Der in diesem Beitrag analysierte Sexismus und Antifeminismus verdeutlicht, wie relevant das UN-Nachhaltigkeitsziel der Bekämpfung von Sexismus und der Durchsetzung der Geschlechtergleichstellung auch in Deutschland noch ist
Analysis and Design of Smart Components in Digital Energy Twins
No full textThe energy crisis, energy demand growth, and dependence on fossil fuels worldwide have made urgent action necessary for us to seek sustainability in energy production and use. Digital technologies, especially Digital Energy Twins, have immense potential to reduce energy consumption, thereby reducing environmental impacts, particularly in the building sector. This paper presents the development of a digital energy twin that supports sustainable energy consumption analysis and optimization. Our study begins with a comprehensive analysis of the energy consumption data, the weather data, and the building plans as a solid basis for the analysis. We identify key energy consumption trends and patterns across different timescales and device-specific details that could be optimized, such as base load consumption and device-specific inefficiencies. A key part of our work is forecasting energy consumption using time series models, such as the ARIMA model, which promises to be useful in identify ing patterns for improving energy efficiency. Overall, our study provides valuable insights into energy optimization and could form the base for further advances in digital energy twins at OTH Regensburg, helping to contribute to its sustainable development goals and smart campus initiatives
Entwicklungsschritte in der EU hin zu einer verpflichtenden Nachhaltigkeitsberichterstattung von Unternehmen
No full textIn Zeiten des Klimawandels, sozialer Ungleichheiten und Ressourcenknappheit ist eine verantwortungsvolle Unternehmensführung essenziell für eine nachhaltige globale Entwicklung der Wirtschaft. Die Nachhaltigkeitsberichterstattung trägt dazu bei, dass Unternehmen ihre ökologischen, sozialen und ökonomischen Auswirkungen transparent für die Stakeholder*innen darstellen und Verantwortung für ihr Handeln übernehmen. Bis zur Finanzkrise 2008 basierte die Nachhaltigkeitsberichterstattung von Unternehmen in der EU auf einer freiwilligen Erstellung, die aber als Konsequenz aus den Lehren der Finanzkrise durch eine Pflicht zur Nachhaltigkeitsberichterstattung ersetzt wurde. Gründe waren u. a., dass das Freiwilligkeitsprinzip der Nachhaltigkeitsberichterstattung nur bedingt die erhofften Impulse für eine an Nachhaltigkeitsaspekten ausgerichtete Unternehmensführung gegeben hat und durch den politischen Willen der EU zur Transformation in eine nachhaltige Wirtschaft und Gesellschaft mittels einer erhöhten Transparenz Kapitalströme in nachhaltige Unternehmen und Geschäftstätigkeiten gelenkt werden sollen
Lebensweltbezug und Hilfe zur Selbsthilfe bei Langzeitarbeitslosigkeit: Ein Beitrag zu nachhaltiger Reintegration in Beschäftigung?
No full textDie Reintegration in Erwerbstätigkeit wird bei langzeitarbeitslosen Personen dann zur Herausforderung, wenn individuelle multiple Problemlagen aus physischen und psychischen Krankheiten, mangelnder sozialer Teilhabe, Schwierigkeiten in der Bewältigung des Alltags und geringen (beruflichen) Kompetenzen vorliegen. Konventionelle Konzepte der Arbeitsmarktdienstleistung, insbesondere auch das Beschäftigungsorientierte Fallmanagement der Jobcenter, sind hier mitunter auch deshalb überfordert, weil zeitliche und materielle Ressourcen für eine angemessene Betreuung nicht ausreichen und das Prinzip der Beschäftigungsorientierung eine niedrigschwellige, ggf. auch aufsuchende sozialpädagogische Unterstützung nicht erlaubt. Der Beitrag beschäftigt sich vor diesem Hintergrund mit den Möglichkeiten, die ein lebensweltbezogenes Fallmanagement für eine nachhaltige berufliche Reintegration eröffnen könnte. Dabei geht es um die Fragen, was Lebensweltorientierung im Bereich der Arbeitsmarktdienstleistung bedeuten kann, welchen Beitrag sie zu einer nachhaltigen Verbesserung sozialer und beruflicher Teilhabe leisten und wie Nachhaltigkeit in diesem Zusammenhang verstanden werden kann
Artificial intelligence-assisted endoscopy and examiner confidence : a study on human–artificial intelligence interaction in Barrett's Esophagus (With Video)
No full textObjective
Despite high stand-alone performance, studies demonstrate that artificial intelligence (AI)-supported endoscopic diagnostics often fall short in clinical applications due to human-AI interaction factors. This video-based trial on Barrett's esophagus aimed to investigate how examiner behavior, their levels of confidence, and system usability influence the diagnostic outcomes of AI-assisted endoscopy.
Methods
The present analysis employed data from a multicenter randomized controlled tandem video trial involving 22 endoscopists with varying degrees of expertise. Participants were tasked with evaluating a set of 96 endoscopic videos of Barrett's esophagus in two distinct rounds, with and without AI assistance. Diagnostic confidence levels were recorded, and decision changes were categorized according to the AI prediction. Additional surveys assessed user experience and system usability ratings.
Results
AI assistance significantly increased examiner confidence levels (p < 0.001) and accuracy. Withdrawing AI assistance decreased confidence (p < 0.001), but not accuracy. Experts consistently reported higher confidence than non-experts (p < 0.001), regardless of performance. Despite improved confidence, correct AI guidance was disregarded in 16% of all cases, and 9% of initially correct diagnoses were changed to incorrect ones. Overreliance on AI, algorithm aversion, and uncertainty in AI predictions were identified as key factors influencing outcomes. The System Usability Scale questionnaire scores indicated good to excellent usability, with non-experts scoring 73.5 and experts 85.6.
Conclusions
Our findings highlight the pivotal function of examiner behavior in AI-assisted endoscopy. To fully realize the benefits of AI, implementing explainable AI, improving user interfaces, and providing targeted training are essential. Addressing these factors could enhance diagnostic accuracy and confidence in clinical practice
Tackling fake images in cybersecurity - interpretation of a StyleGAN and lifting its black-box
No full textIn today's digital age, concerns about the dangers of AI-generated images are increasingly common. One powerful tool in this domain is StyleGAN (style-based generative adversarial networks), a generative adversarial network capable of producing highly realistic synthetic faces. To gain a deeper understanding of how such a model operates, this work focuses on analyzing the inner workings of StyleGAN's generator component. Key architectural elements and techniques, such as the Equalized Learning Rate, are explored in detail to shed light on the model's behavior. A StyleGAN model is trained using the PyTorch framework, enabling direct inspection of its learned weights. Through pruning, it is revealed that a significant number of these weights can be removed without drastically affecting the output, leading to reduced computational requirements. Moreover, the role of the latent vector -- which heavily influences the appearance of the generated faces -- is closely examined. Global alterations to this vector primarily affect aspects like color tones, while targeted changes to individual dimensions allow for precise manipulation of specific facial features. This ability to finetune visual traits is not only of academic interest but also highlights a serious ethical concern: the potential misuse of such technology. Malicious actors could exploit this capability to fabricate convincing fake identities, posing significant risks in the context of digital deception and cybercrime
Data-driven model order reduction with surrogate elements for transient simulations
No full textPurpose – The purpose of this study is to introduce surrogate elements for static and transient finite element simulations. These elements are designed to replace regions of several conventional solid elements with a single artificial element that possesses a reduced number of degrees of freedoms (dofs). A notable advantage of our surrogate elements is their seamless integration into standard finite element meshes.
Design/methodology/approach – The construction of the surrogate elements stiffness and mass matrices is achieved through an optimization process wherein displacements serve as the optimization objective. Moreover, the matrices are designed to possess properties analogous to those of standard finite elements. A particular focus is placed on ensuring that the artificial stiffness matrices are positive semi-definite. Furthermore, artificial degrees of freedom are introduced.
Findings – The efficacy of the proposed technique is demonstrated through its application to two different use cases. It is demonstrated that, despite being trained on examples comprising a single surrogate element, the surrogate elements can be employed multiple times within complex and practical models. The degree of accuracy achieved in these applications is noteworthy. Moreover, the proposed method is considerably faster than the fully discretized models.
Originality/value – The study expands the field of substructuring and model order reduction by incorporating artificial surrogate elements built by neural networks, which enables seamless integration with standard finite element analysis via positive semi-definite matrices. Furthermore, the introduction of artificial degrees of freedom, which are detached from the computational domain, is proposed. Once trained, the surrogate elements can be utilised in load and support independent scenarios
