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Wanderer zwischen Welten: Telegramnutzung aus Perspektive der Nutzenden
Full text linkThe messenger Telegram has gained importance for the mediated constitution of counterpublics in German-speaking countries since 2020. However, most research on Telegram focuses on the content shared and the networks that have developed on the platform. Meanwhile, knowledge about the users of counterpublic Telegram channels and groups and their processes of appropriating the messenger is very limited. Based on 14 in-depth interviews with users, this article explores how individuals connect with like-minded people on Telegram, how they process the information they receive there and why they are attracted to the medium in general. We group them in our analysis according to the meaning they ascribe to the Telegram community, their media repertoires, and how they negotiate contradictions between counterpublic and mainstream information, developing a typology of four types: (1) topic-oriented users, (2) confident researchers, (3) libertarian activists and (4) alienated users.Seit 2020 hat der Messenger-Dienst Telegram an Bedeutung für die mediale Konstitution von Gegenöffentlichkeiten im deutschsprachigen Raum gewonnen. Deshalb wird er häufig zum Gegenstand kommunikationswissenschaftlicher Forschung. Der Großteil der Studien über Telegram arbeitet jedoch inhaltsanalytisch oder untersucht die Netzwerke, die sich auf der Plattform entwickeln. Das Wissen über Telegram-Nutzer*innen und über die Praktiken, mit denen sich diese den Messenger aneignen, ist dagegen sehr begrenzt. Auf der Grundlage von 14 Tiefeninterviews mit Nutzer*innen untersucht dieser Artikel, wie Menschen Telegram zur Vergemeinschaftung nutzen, wie sie die Informationen, die sie dort erhalten, verarbeiten und was Telegram-Nutzung für sie attraktiv macht. In unserer Analyse gruppieren wir die Nutzer*innen nach der Bedeutung, die sie der Telegram-Gemeinschaft zuschreiben, nach ihrem Medienrepertoire und danach, wie sie Widersprüche zwischen Informationen aus Gegenöffentlichkeit und Mainstream-Medien verarbeiten. Darauf basierend entwickeln wir vier Typen: (1) Monothematisch ausgerichtete Nutzer*innen (2) selbstbewusste Rechercheur*innen, (3) libertäre Aktivist*innen und (4) entfremdete Nutzer*innen
Institutionelle Strukturen und volkswirtschaftlicher Wohlstand
Full text linkDieser Beitrag untersucht, welche Faktoren den Wohlstand von Volkswirtschaften beeinflussen. Ein besonderer Fokus liegt dabei auf der Rolle von Institutionen, wie sie aus der Perspektive der Neuen Institutionenökonomik verstanden werden, durch Modelle von Acemoglu, Johnson und Robinson. Diese wurden im Jahr 2024 mit dem Wirtschaftsnobelpreis ausgezeichnet. Der vorliegende Artikel zielt darauf ab, den Zusammenhang zwischen Institutionen, Demokratie und Wohlstand mittels einer qualitativen Analyse von Fachliteraturquellen darzustellen
Evaluating the Potential of Drone Imagery for Monitoring Hydromorphological properties: a case study in the Erft River Restoration in Neuss- Gnadental, Germany
Full text linkThis research aims at evaluating the use of drone (UAV) imagery in the monitoring of hydromorphological changes in a segment of Erft River in Neuss-Gnadental, which has undergone restoration. In four flight campaigns from February 2022 to November 2023, UAV images were processed with open-source photogrammetry and point clouds processing software (WebODM and CloudCompare) to create 2D orthophotos and 3D point clouds. These products supported delineation of the channel and calculation of geometric properties such as the length, sinuosity, and number of meanders which indicated good correspondence with restoration design objectives and continuous morphological changes like erosion, sediment bars, and woody debris.
Hydromorphological quality at the segment scale was assessed by employing an adapted LAWA protocol using only the 2D orthomosaics and 3D point clouds. Analysis showed that restoration of the river segment produced improvements in characteristics such as flow variety, substrate type, and banks while the near “technical” parts of the segment experienced small alterations. The UAV flights were conducted frequently, enabling documentation of seasonal fluctuations that might not have been observed if the surveys had been carried out using satellite imagery.
Certain advantages included centimetre-resolution imagery, flexibility in flight schedules, and visuals friendly to stakeholder impact. Nevertheless, there were specific workflow challenges. Utilising photogrammetry on open-source tools had high computational costs and required hands-on troubleshooting. Vegetation overshadows complicated semi-automated classification routines and requires manual refinement for reliable channel delineation. However, the approach proved effective for high-resolution, local-to-reach-scale monitoring, strengthening adaptive, data-driven management of river restoration sites.
Subsequent campaigns should include data from multiple sensors (LiDAR, multispectral), the inclusion of classification algorithms, and longer, repeated surveys to evaluate the hydromorphological characteristics under different flow conditions. In summary, UAV imagery enhances hydromorphological monitoring and provides a powerful yet still-developing tool for science-based evaluation of restoration efforts
Thermo‐Oxidative Aging and Performance Comparison of Recovered, Sustainable, and Virgin Carbon Black in Ethylene Propylene Diene Monomer‐Based Elastomers
Full text linkPyrolysis is becoming increasingly important in the context of recycling and the volume of end-of-life tires worldwide. Sustainable carbon black (sCB), which is produced from pyrolysis oil instead of crude oil, and recovered carbon black (rCB), which is the remaining solid from pyrolysis, are promising secondary raw materials for rubber compounds as a substitute for industrial carbon black produced from fossil resources. This study investigates the possibility of substituting carbon black N550 partially or fully in an EPDM (Ethylene Propylene Diene Monomer) sealing compound. rCB contains impurities that affect the properties of the compound. Aging at higher temperatures, in the presence of oxygen is studied. The properties of the compounds are evaluated after heat treatment in air at different temperatures for up to 6 weeks. The results show that sCB is very close to N550 as a raw material and in terms of its in-rubber properties. Due to the impurities, rCB alters the cross-linking density and structure of the polymer-sulfur network (shift to polysulfidic structure). Lower reinforcement is also observed, which is related to weaker polymer-filler (decrease of I3/1 for sCB by 3% and rCB by 43% related to vCB) and filler-filler interactions. Aging effects are also more pronounced in the compounds containing rCB
Precise Control of Eye Movement for Real-Time Video Funduscopy and OCT Using Dynamic Fixation Patterns
Full text linkThis paper presents a method for dynamically controlling the gaze movement of patients during ophthalmic examinations, specifically using infrared funduscopy and Optical Coherence Tomography (OCT) to gather retinal information essential for glaucoma screenings. By using the patient's natural eye movements, this system eliminates the need for traditional precise scanning mirrors used in conventional OCT devices, which typically direct the OCT laser beam across the retina to produce A-scans. In this approach, the OCT laser beam remains fixed while the patient is guided to follow a predetermined pattern on a display with their eyes. This method effectively uses the patient’s eye movements to replace the functionality of scanning mirrors. By tracking the position of the eye in real time, the system ensures that the specific areas of the retina are captured. This technique not only provides a cost-effective alternative to traditional OCT systems but also enhances patient comfort by involving them actively in the process, reducing the need to fixate on a single point. During the examination, the system evaluates each measurement point, and the scan patterns can be adjusted if necessary to ensure comprehensive diagnostic data acquisition. The resulting positions are assigned to the OCT A-scans. This allows the optic nerve B-scans typical for glaucoma examinations to be created in the evaluation. The system is characterized by the fact that it enables flexible adjustments to the imaging patterns in real-time, based on which areas of the eye have already been captured and which still require examination. The setup mainly uses commercially available components to create a cost-effective alternative to conventional, often price-intensive diagnostic devices. This method has the potential to be important not only for the improved diagnosis and monitoring of eye diseases, including glaucoma, but also offers prospects for wider application in preventive eye health care
A Qualitative Exploration of Concurrency Misconceptions Among Novice Kotlin Programmers
Full text linkConcurrency is a fundamental concept in modern computing, allowing systems to execute multiple tasks in parallel to achieve responsiveness and efficiency. Despite its importance, concurrency remains a difficult topic for novice programmers, with prior studies documenting persistent misconceptions that hinder their ability to develop and reason about concurrent programs. Kotlin, an increasingly adopted programming language, introduces a coroutine-based concurrency model that offers unique challenges for learners.
Little research has explored misconceptions in this specific context, however. Improving concurrency education requires a deeper understanding of how students reason about concurrent concepts. This thesis aims to address this need, by focusing on novice Kotlin programmers at the Cologne University of Applied Sciences. We present a qualitative study that investigates students’ misconceptions and mental models of concurrency, by the use of code-based exercises. Using a think-aloud protocol and subsequent content analysis, we illuminate a range of misconceptions related to sequential thinking, launching of coroutines, synchronisation, as well as thread safety. Here we examine a collection of misconceptions, laying a foundation for improving concurrency education in Kotlin at Cologne UAS
Active Gaze Guidance and Pupil Dilation Effects Through Subject Engagement in Ophthalmic Imaging
Full text linkModern ophthalmic imaging methods such as optical coherence tomography (OCT) typically require expensive scanner components to direct the light beam across the retina while the patient’s gaze remains fixed. This proof-of-concept experiment investigates whether the patient’s natural eye movements can replace mechanical scanning by guiding the gaze along predefined patterns. An infrared fundus camera setup was used with nine healthy adults (aged 20–57) who completed tasks comparing passive viewing of moving patterns to actively tracing them by drawing using a touchpad interface. The active task involved participant-controlled target movement with real-time color feedback for accurate pattern tracing. Results showed that active tracing significantly increased pupil diameter by an average of 17.8% (range 8.9–43.6%; p < 0.001) and reduced blink frequency compared to passive viewing. More complex patterns led to greater pupil dilation, confirming the link between cognitive load and physiological response. These findings demonstrate that patient driven gaze guidance can stabilize gaze, reduce blinking, and naturally dilate the pupil. These conditions might enhance the quality of scannerless OCT or other imaging techniques benefiting from guided gaze and larger pupils. There could be benefits for children and people with compliance issues, although further research is needed to consider cognitive load
Innovative angewandte Produktionsforschung - Tagungsband zum Wissenschaftlichen Track der DigitalXChange 2025
Full text linkIm Rahmen der DigitalXChange Konferenz 2025 wurde erstmals ein wissenschaftlicher Track zum Thema Innovative, angewandte Produktionsforschung an HAW abgehalten. Forschende aus unterschiedlichen deutschen Hochschulen haben hierzu Beiträge eingereicht
Gaming the Metaverse
Full text linkNeal Stephenson’s 1992 novel Snow Crash conceived of the Metaverse as an escapist medium within a dystopian future. By the early 2000s, his vision had evolved into a blueprint for pioneering virtual worlds, notably Second Life. In the 2010s, technology companies—from Meta to Epic Games—recast the Metaverse as the next frontier of digital experience and revenue generation. Now, in the 2020s, the still speculative concept encompasses a convergence of extended reality technologies alongside blockchain systems and artificial intelligence. The contributors bring together leading scholars and industry professionals to examine past “imaginations” and recent “achievements” in the pursuit of the Metaverse. They trace its development through literary, media, and cultural history while exploring current applications and their technical, social, cultural, and economic implications
Aufbau von modernen Datenplattformen in der Cloud - Überblick und Umsetzung von Modern Data Warehouse, Data Lakehouse und Data Mesh
Full text linkDie vorliegende Masterarbeit untersucht die aktuellen Architekturkonzepte für den Aufbau einer Cloud-Datenplattform. Dabei werden die Konzepte Modern Data Warehouse, Data Lakehouse und Data Mesh anhand aktueller Literatur evaluiert. Zur Herstellung eines Praxisbezugs werden diese Konzepte im Kontext der führenden Technologieanbieter Azure, AWS, Databricks und Snowflake analysiert und die entsprechenden Komponenten zur Umsetzung der Konzepte erörtert.
This master's thesis examines the current architectural concepts for buildingThis master's thesis examines the current architectural concepts for building a cloud data platform. The concepts of Modern Data Warehouse, Data Lakehouse and Data Mesh are evaluated on the basis of current literature. To establish a practical reference, these concepts are analyzed in the context of the leading technology providers Azure, AWS, Databricks and Snowflake and the corresponding components for implementing the concepts are discussed