Hochschule Bonn-Rhein-Sieg
Publikationsserver der Hochschule Bonn-Rhein-Sieg - pub H-BRSNot a member yet
7939 research outputs found
Sort by
Die Richtlinie 2024/2831 zur Verbesserung der Arbeitsbedingungen in der Plattformarbeit: Konsequenzen und Herausforderungen für den Gesetzgeber
No full textExtended Workspace: Techniques for Interaction with Off-Screen Objects in Augmented Reality
No full textDer Einfluss von Gravitation auf die Wahrnehmung der Eigenbewegung (SMUG – Self-Motion Under Gravity)
No full textDie Wahrnehmung und Interaktion des Menschen mit seiner Umgebung beruht auf einer multisensorischen Integration von Reizen. Dieser Prozess – visuelle, auditive, taktile, vestibuläre und propriozeptive Signale kombiniert zu verwenden – hat sich beim Menschen entwickelt, um bei einer konstanten Gravitation von 1g auf der Erde zurechtzukommen. Es ist daher nicht überraschend, dass Abweichungen von dieser g-Bedingung zu systematischen Fehlern in der Wahrnehmung und im Handeln führen können.
Der Einfluss verschiedener Stimuli – insbesondere die Gravitation – auf die Wahrnehmung der Eigenbewegung und ob hierbei geschlechtsspezifische Unterschiede vorliegen, sollte mit Hilfe von Experimenten untersucht werden, bei denen den Probanden/innen ausschließlich visuellen Reize (optischen Fluss) zur Verfügung gestellt wurden. Insgesamt nahmen 42 Teilnehmer/innen (je 21 Frauen und Männer) an 5 verschiedenen Messzeitpunkten (vor, während und nach Parabelflügen des DLR und der ESA) im Sitzen, Liegen und Schweben teil. Die Probanden/innen trugen ein Head-Mounted Display (HMD), mit Hilfe dessen ihnen der Eindruck vermittelt wurde, sich in einem virtuellen Korridor zu befinden bzw. sich durch diesen zu bewegen. Die Wahrnehmung der Eigenbewegung wurde anhand von zwei Tests gemessen, bei denen die Probanden/innen eine simulierte Bewegung über verschiedene Distanzen (5m - 38m) erlebten. Die Aufgabe bestand darin, entweder die visuell induzierte Bewegung zu stoppen, sobald sie die Position eines zuvor angezeigten Ziels erreicht hatten (Move-to-Target Test), oder eine zuvor zurückgelegte Distanz durch die Positionierung eines Ziels anzugeben (Adjust-Target Test)
Entgegen der Ergebnisse vorheriger Studien deuten die aktuellen Rohdaten auf einen Unterschied zwischen Männern und Frauen bzgl. ihrer Wahrnehmung der Eigenbewegung in verschiedenen Testbedingungen hin. Die erhobenen Rohdaten wurden mithilfe des „leaky spatial integrator models“ analysiert. Das Modell von Lappe et al. (2007) geht davon aus, dass die Schätzung der visuellen Bewegung durch den Teilnehmer ein abnehmender Integrator ist. Das Lappe-Modell hat zwei freie Parameter: einen Verstärkungsterm „k“ (entsprechend der Empfindlichkeit gegenüber dem optischen Fluss) und einen räumlichen Abklingterm „alpha“ (der angibt, wie viel Entfernung mit zunehmender Gesamtentfernung vergessen wird).
Im Anschluss an die Berechnung aller im SMUG Experiment erhobenen Daten (sprich, Move-to-Target und Adjust-Target Test über alle Distanzen von allen Probanden/innen) wurde bzgl. beider freier Parameter überprüft, ob der Faktor „Geschlecht“ einen Einfluss hat. Es zeigte sich dabei ein signifikanter Unterschied, sofern das Geschlecht als Faktor berücksichtigt wird (Chi^2(6)=15.665, p=0.01567). Dies trifft für die Berechnung der alpha-Werte jedoch nicht zu.
Auf Grundlage der bisher durchgeführten Untersuchungen lässt sich zusammenfassen, dass der Fokus zukünftiger Forschungsprojekte auf der Erfassung der Wahrnehmung der Eigenbewegung von Astronauten/innen hinsichtlich verschiedenen g-Bedingungen sowie deren Geschlecht gelegt werden sollte. Dies scheint für die Planung zukünftiger Missionen zum Mond und Mars eine große Rolle zu spielen und könnte bereits vor der Mission erfasst und möglicherweise aufgaben-spezifisch berücksichtigt werden.Human perception and interaction with the environment is based on stimuli-dependent multisensory integration. This process - using visual, auditory, tactile, vestibular and proprioceptive signals in combination - has evolved in humans to cope with a constant gravity of 1g on Earth. It is therefore not surprising that deviations from this g-state can lead to systematic errors in perception and action.
The influence of different stimuli - in particular gravity - on the perception of self-motion and whether there are gender-specific differences in this context was investigated by experiments in which the participants were provided with visual stimuli only (optical flow). A total of 42 participants (21 females and 21males) took part at five different measurements (before, during and after parabolic flights by DLR and ESA) while sitting, lying supine and free floating. The participants wore a head-mounted display (HMD) which gave them the impression of being in a virtual corridor and moving through it. The perception of self-motion was measured using two tests in which the participants experienced simulated motion at different distances (5m - 38m). The task was either to stop the visually induced movement as soon as they have reached the position of a previously viewed target (Move-to-Target test) or to indicate a previously travelled distance by positioning a target (Adjust-Target test) – see Chapter I.3.
In contrast to the results of previous studies, the current raw data indicate a difference between men and women in their self-motion perception under different test conditions. The collected raw data were analyzed using the “leaky spatial integrator model.” The model by Lappe et al. (2007) assumes that the participant's estimation of visual motion is a decreasing integrator. The Lappe model has two free parameters: a gain term “k” (corresponding to sensitivity to optical flow) and a spatial decay term “alpha” (which indicates how much distance is not remembered with increasing total distance).
Following the calculation of all collected data in the SMUG experiment (i.e., Move-to-Target and Adjust-Target tests across all distances for all test subjects), both free parameters have been evaluated to determine whether the factor “gender” had an influence. A significant difference was found when gender was taken into account as a factor (Chi^2(6)=15.665, p=0.01567). However, this does not apply to the calculation of the alpha values.
Based on the already conducted studies, it can be concluded that future research projects should focus on the analysis of astronauts' perception of self-motion in different g-conditions and in relation to their gender. This appears to play an important role in the planning of future missions to the moon and Mars and could be evaluated before the mission and possibly taken into account in a task-specific manner
Demokratische Neujustierung der gesetzlichen Unfallversicherung: Die Reform von 1925 und der Ausbau der sozialen Sicherheit
No full textHDR Merging of RAW Exposure Series for All-Sky Cameras: A Comparative Study for Circumsolar Radiometry
No full textAll-sky imagers (ASIs) used in solar energy meteorology face an extreme intra-image dynamic range, with the circumsolar neighborhood orders of magnitude brighter than the diffuse dome. Many operational ASI pipelines address this gap with high-dynamic-range (HDR) bracketing inside the camera’s image signal processor (ISP), i.e., after demosaicing and color processing in a nonlinear 8-bit RGB domain. Near the Sun, such ISP-domain HDR can down-weight the shortest exposure, retain clipped or near-clipped samples from longer frames, and compress highlight contrast, thereby increasing circumsolar saturation and flattening aureole gradients. A radiance-linear HDR fusion in the sensor/RAW domain (RAW–HDR) is therefore contrasted with the vendor ISP-based HDR mode (ISP–HDR). Solar-based geometric calibration enables Sun-centered analysis. Paired, interleaved acquisitions under clear-sky and broken-cloud conditions are evaluated using two circumsolar performance criteria per RGB channel: (i) saturated-area fraction in concentric rings and (ii) a median-based radial gradient in defined arcs. All quantitative analyses operate on the radiance-linear HDR result; post-merge tone mapping is only used for visualization. Across conditions, ISP–HDR exhibits roughly double the near-saturation within 0–4∘ of the Sun and about a three- to fourfold weaker circumsolar radial gradient within 0–6∘ relative to RAW–HDR. These findings indicate that radiance-linear fusion in the RAW domain better preserves circumsolar structure than the examined ISP-domain HDR mode and thus provides more suitable input for downstream tasks such as cloud–edge detection, aerosol retrieval, and irradiance estimation
BPMN Thread Split – How to Start Multiple Tasks at Once
No full textThis video introduces the Thread Split pattern and explains how BPMN can initiate multiple execution threads at a specific point within a process model.
The Thread Split pattern describes situations in which a single thread of control is deliberately divided into several concurrent execution threads. Using the original workflow patterns animation as a conceptual reference, the video illustrates how tokens are duplicated to activate multiple downstream paths simultaneously.
The tutorial then demonstrates how this behavior can be modeled in BPMN, with particular attention to the completionQuantity attribute and its practical use in the Camunda Modeler. A step-by-step walkthrough shows how multiple task instances can be generated from a single activation point, enabling parallel processing while maintaining structured control flow.
This video is part of a series on modeling workflow patterns with BPMN: http://www.workflowpatterns.com
This is Video #42 of the BPMN Series. Supplementary material is available on GitHub: https://github.com/ahense/bpmn
The examples were modeled using the Camunda Modeler: https://modeler.cloud.camunda.i
ChatGPT as Economics Tutor: Capabilities and Limitations
No full textThe dataset comprises responses generated by ChatGPT using three different models (GPT-3.5, GPT-4o, and o1preview) evaluated for their effectiveness as an automated tutor in economics education at universities. The dataset focuses on two key use cases:
Explanations of 56 Basic Economic Concepts
Answers and Explanations to 25 Multiple-Choice Questions
The concepts and questions were sourced from CORE Econ’s The Economy 1.0 textbook. The selected content includes foundational ideas like "Opportunity Costs" and "Aggregate Demand," as well as more advanced topics such as "Asymmetric Information" and "Economic Rent."
Responses were generated using standardized prompts that simulate student interactions with ChatGPT. Each response was evaluated using a detailed marking grid that included both problem-specific and response-specific indicators—such as accuracy, scope, error types. A moderation process was applied to ensure reliability, with disagreements resolved through discussion.
The final dataset consolidates all model outputs, and their evaluations. It is suitable for analyzing the pedagogical potential and limitations of large language models in educational contexts. Further, all scripts used to evaluate the responses and perform the statistical analysis are included.
For more detail see the paper: Brose, Natalie, Christian Spielmann, and Christian Tode. ChatGPT as Economics Tutor: Capabilities and Limitations. School of Economics, University of Bristol, UK, 2025.
https://econpapers.repec.org/RePEc:bri:uobdis:25/78
The evolutionary path of the epithelial sodium channel δ-subunit in Cetartiodactyla points to a role in sodium sensing
No full textThe epithelial sodium channel (ENaC) is essential for osmoregulation in tetrapod vertebrates. There are four ENaC-subunits (α, β, γ, δ) which form αβγ- or δβγ-ENaCs. While αβγ-ENaC is a ‘maintenance protein’ controlling sodium homeostasis, δβγ-ENaC might represent a ‘stress protein’ monitoring high sodium concentrations. The δ-subunit emerged with water-to-land transition of vertebrates. We examined ENaC evolution in Cetartiodactyla, a group including even-toed ungulates and cetaceans (whales, dolphins and porpoises) which returned to marine environments in the Eocene. Genes for α-, β-, and γ-ENaC are intact across Cetartiodactyla. While SCNN1D (δ-ENaC) is intact in terrestrial Artiodactyla, it is a pseudogene in cetaceans. A unique fusion of SCNN1D exons 11 and 12 is observed in the Antilopinae. Transcripts of α-, β-, and γ-ENaC are present in kidney, lung and skin tissues of Bottlenose dolphins, underscoring αβγ-ENaC’s maintenance role. Bottlenose dolphins and Beluga whales do not show behavioural differences between sodium-containing and sodium-free stimuli, supporting a function of δ-ENaC as a sodium sensing protein which might have become obsolete in high-salinity marine environments. Consistently, there is reduced selection pressure or pseudogenisation of SCNN1D in other marine mammals. Erosion of SCNN1D might therefore be a consequence of environmental transition in marine mammals
A Gate Drive Circuit for GaN GIT Power Semiconductors with a Minimal Number of Components
No full textLongitudinal Study of Facial Biometrics at the BEZ: Temporal Variance Analysis
No full textThis study presents findings from long-term biometric evaluations conducted at the Biometric Evaluation Center (bez). Over the course of two and a half years, our ongoing research with over 400 participants representing diverse ethnicities, genders, and age groups were regularly assessed using a variety of biometric tools and techniques at the controlled testing facilities. Our findings are based on the General Data Protection Regulation-compliant local bez database with more than 238.000 biometric data sets categorized into multiple biometric modalities such as face and finger. We used state-of-the-art face recognition algorithms to analyze long-term comparison scores. Our results show that these scores fluctuate more significantly between individual days than over the entire measurement period. These findings highlight the importance of testing biometric characteristics of the same individuals over a longer period of time in a controlled measurement environment and lays the groundwork for future advancements in biometric data analysis