TY - JOUR A1 - Elíasson, Jonas A1 - Weber, Konradin A1 - Vogel, Andreas A1 - Pálsson, Thorgeir A1 - Yoshitani, Junichi A1 - Miki, Daisuke T1 - Investigation and Separation of Turbulent Fluctuations in Airborne Measurements of Volcanic Ash with Optical Particle Counters JF - Journal of Disaster Research N2 - The science of measuring airborne volcanic ash concentrations supports research in such fields as atmospheric environmental science and the modeling of atmospheric pollution from volcanoes, and is thus very valuable to the aviation industry. These measurements show large scatter directly traceable to turbulent fluctuations responsible for diffusing volcanic dust. Before semistationary components in observations can be compared to each other or to simulation results, they must be separated from fluctuations. In the design of the separation process, however, neither seasonal or diurnal periodicity nor random disturbance with known properties exists to serve as a guideline. It has been suggested that fluctuations could be eliminated through repeated convolutions of a simple 3-point filter enough times. The number of convolutions is chosen from the change in the rate of increase of a special variability parameter. When semistationary concentrations are separated from fluctuations, their statistics are compared to turbulence parameters and the autocorrelation of the series. The method is demonstrated using three measurement series from Sakurajima, Japan measured in 2013. It is concluded that this new method is simple and trustworthy where knowledge and experience of the environmental parameters can be utilized to support the results. They indicate a variability of 40% in the relative fluctuations of the PM10 and around 20% of the PM2.5. The relative fluctuations may be considered completely random, but normally distributed rather than a white noise with an evenly distributed variance spectrum. KW - Luftreinhaltung Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-50023 SN - 1883-8030 VL - 11 IS - 1 SP - 72 EP - 84 PB - Fuji Technology Press Ltd. ER - TY - CHAP A1 - Versümer, Siegbert A1 - Steffens, Jochen T1 - Investigating real indoor soundscapes and their predictability for known and unknown subjects [Vortrag] T2 - Fortschritte der Akustik - DAGA 2024, 18. - 21. März 2024, Hannover N2 - Understanding people's perception of everyday sound involves a complex interplay of various acoustic and non-acoustic factors. Our objective is to uncover important predictors for predicting real indoor soundscapes. To this end, we re-analyzed soundscape data recorded and evaluated by individuals in their homes, aiming for the utmost ecological validity. Given the intricate nature of sound perception and potential non-linear effects of acoustic and psychoacoustic predictors, we utilized machine-learning methods combined with hierarchical linear modeling to analyze 6375 soundscapes from 96 participants including acoustical, psychoacoustical, as well as situational und person-related predictors. Based on this analysis, we measured both the variability within and between subjects and obtained model fits for the prediction of both soundscape pleasantness and eventfulness. In order to discuss cases where predictions for known individuals or places are of interest, we employed (nested) cross-validation using different data-splitting methods. By doing so, our study sheds light on the generalizability of empirical findings when predicting soundscape evaluations for unknown or known subjects and thus supports a deeper understanding of everyday sound perception. KW - Vortrag Y1 - 2024 PB - Deutsche Gesellschaft für Akustik e.V. CY - Berlin ER - TY - THES A1 - Thielen, Sven T1 - Investigating JackTrip's Software Architecture: A Case Study On Prominent Reasons For Architectural Erosion In Open Source Software Originating From Academia N2 - Sustainable software architecture is crucial for the success of an evolving system that is affected by its context and environment. However, deviations between software design and implementation are often uncontrolled and induce architectural erosion. The literature describes several symptoms and observes this phenomenon in open source software. Prominent reasons for the occurrence of architectural erosion include a rushed evolution, recurring changes, a lack of developers' awareness, time pressures, and the accumulation of design decisions. Architectural erosion is also prevalent in academic projects, but it still needs to be researched in-depth in a real-life setting. In this work, a single case study investigates the symptoms and reasons for architectural erosion in open source software originating from academia by employing a mixed-methods approach. Architectural metrics from a static code analysis using ARCADE Core are contrasted with developers' perspectives sourced from semistructured interviews. The investigated project is JackTrip, a cross-platform application for realtime networked music performances and Internet reverberation research. The first research question aims at assessing the trend of structural symptoms for architectural erosion in JackTrip. The results show a significant increase in link overload smells in the course of the evolution, which reached 11 as of version 1.6.2. This supports the developers' perception of a rushed evolution corresponding to the second research question, which asks to what extent prominent causes for architectural erosion apply. Additionally, the interview data evince time constraints related to tight research funding and the commercialization of the project. Research question 3 investigates how the academic environment and the problem domain relate to the symptoms and reasons for architecture erosion. It has been found that these influences shape the development approach and impact contributor selection. In relation to a certain inexperience and lack of commitment of open source developers as a reason for architectural erosion, the results suggest further studies and opt for ending the discussion regarding skills. Currently, the role of an architect or dedicated architectural work does not seem to be present in the JackTrip project. However, structural issues described in this work should not be considered as categorical statements about its software architecture as they would need to be confirmed on a code level. KW - Software Architecture KW - Architecture Erosion KW - Software Evolution KW - Academic Software KW - Open Source Software Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-44153 PB - Hochschule Düsseldorf CY - Düsseldorf ER - TY - JOUR A1 - Tarlao, Cynthia A1 - Steffens, Jochen A1 - Guastavino, Catherine T1 - Investigating contextual influences on urban soundscape evaluations with structural equation modeling JF - Building and Environment KW - Soundscape KW - Extraversion KW - Social interaction KW - Structural equation modeling KW - Measurement invariance KW - ISAVE Y1 - 2021 U6 - https://doi.org/10.1016/j.buildenv.2020.107490 SN - 0360-1323 N1 - Manuskriptversion ist als Open Access verfügbar (Open Access Grün): https://escholarship.mcgill.ca/concern/articles/q811kq411?locale=en VL - 188 PB - Elsevier ER - TY - JOUR A1 - Benim, Ali Cemal T1 - Introducing the “Mathematical Modelling and Numerical Simulation of Combustion and Fire” Section of the Journal Fire JF - fire Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-40257 SN - 2571-6255 VL - 5 IS - 6 PB - MDPI ER - TY - RPRT A1 - Khabyuk, Olexiy T1 - Introducing state-distant public broadcasting in Ukraine Y1 - 2011 SN - 978-3-938933-94-7 VL - Arbeitspapiere des Instituts für Rundfunkökonomie an der Universität zu Köln IS - 286 PB - Inst. für Rundfunkökonomie, Univ. Köln CY - Köln ER - TY - CHAP A1 - Herder, Jens A1 - Vonolfen, Wolfgang A1 - Griesert, Arnfried A1 - Heuer, Stefan A1 - Hoffmann, Ansgar A1 - Höppner, Bernd T1 - Interactive Virtual Set Applications for Post Production T2 - University of Aizu 2004 – Seventh International Conference on Human N2 - Virtual set environments for broadcasting become more sophisticated as well as the visual quality improves. Realtime interaction and production-specific visualization implemented through plugin mechanism enhance the existing systems like the 3DK. This work presents the integration of the Intersense IS-900 SCT camera tracking and 3D interaction into the 3DK virtual studio environment. The main goal of this work is the design of a virtual studio environment for post productions, which includes video output as well as media streaming formats such as MPEG-4. The systems allows high quality offline rendering during post production and 3D interaction by the moderator during the recording. KW - interaction KW - tracking KW - virtual set environments KW - Virtual (TV) Studio KW - post production KW - MPEG-4 KW - FHD KW - VSVR Y1 - 2004 CY - Aizu-Wakamatsu ER - TY - JOUR A1 - Griesert, Arnfried A1 - Walczak, Oliver A1 - Herder, Jens T1 - Interactive Realtime Terrain Visualization for Virtual Set Applications JF - Journal of the 3D-Forum Society N2 - Virtual set environments for broadcasting become more sophisticated as well as the visual quality improves. Realtime interaction and production-specific visualization implemented through plugin mechanism enhance the existing systems like the virtual studio software 3DK. This work presents an algorithm which can dynamically manage textures of high resolution by prefetching them depending on their requirement in memory and map them on a procedural mesh in realtime. The main goal application of this work is the virtual representation of a flight over a landscape as part of weather reports in virtual studios and the interaction by the moderator. KW - 3D KW - VSVR KW - Virtual (TV) Studio Y1 - 2003 VL - 17 IS - 4 SP - 20 EP - 26 ER - TY - CHAP A1 - Herder, Jens T1 - Interactive Content Creation with Virtual Set Environments T2 - Fourth International Conference on Human and Computer N2 - Digital broadcasting enables interactive \sc tv, which presents new challenges for interactive content creation. Besides the technology for streaming and viewing, tools and systems are under development that extend traditional \sc tv studios with virtual set environments. This presentation reviews current technology and describes the requirements for such systems. Interoperability over the production, streaming, and viewer levels requires open interfaces. As the technology allow more interaction, it becomes inherent difficult to control the quality of the viewers experience KW - VSVR KW - digital broadcasting Y1 - 2001 PB - University of Aizu CY - Aizu-Wakamatsu ER - TY - JOUR A1 - Herder, Jens T1 - Interactive Content Creation with Virtual Set Environments JF - Journal of the 3D-Forum Society N2 - Digital broadcasting enables interactive \sc tv studios with virtual set environments. This presentation reviews current technology and describes the requirements for such systems. Interoperability over the production, streaming, and viewer levels requires open interfaces. As the technology allow more interaction, it becomes inherent difficult to control the quality of the viewers experience. KW - Interactive Media KW - Sound Spatialization KW - Virtual Sets KW - virtual studio KW - VSVR Y1 - 2001 VL - 15 IS - 4 SP - 53 EP - 56 ER - TY - JOUR A1 - Kim, Hyun Kang T1 - Intensity, Manifestation, and Performance in the Politics of the Real JF - International Journal of Philosophy N2 - This study attempts to explain the concept of the real in terms of intensity, manifestation, and performance, and then outlines key aspects of the politics of the real. The politics of the real is based on an interruption of identification and an abrupt end of continuity, and intensity, manifestation, and performance are the modalities of the politics of the real. First, intensity is the principle of punctualization. It denotes an anti-dialectic and anti-systematic enterprise that aims to leave behind the paradigm of continuity. It acts as the counter-principle to overcome the Hegelian dialectic and historicism. It concerns the dimension before the formation of identity and thus functions as a categorical rejection of ontological identity. Consequently, it evolves into a figure of future politics, because it denies identity and instead affirms new inventions. Second, manifestation is a matter of politics, because politics shows itself as a matter of visibility and demonstration. Ultimately, politics is the fight over manifestation. Furthermore, manifestation is the modality of existence of the collective, since a new arising collective always manifests itself in the space of images. Finally, performance is an action concept and thus opposed to the static world-model. Hence, the world appears as the place for restructuring and reshaping. Performance renders reference and the classical notion of mimesis obsolete. It undermines the distinction between original and copy and instead affirms the permanent generating of new relations and nexuses. Hence, it is the generation of freedom. Ultimately, it acts as a disappearing intermediary between virtual intensity and actual manifestation. It is an anti-metaphysical concept of possibility that differs strictly from metaphysical possibility. Thus, intensity, manifestation, and performance each correspond to the virtual, actual, and possible of the real and thus are to be denoted as modalities of the politics of the real. KW - Wirklichkeit KW - Performance (Künste) KW - Intensität KW - Ästhetik Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-54465 SN - 2330-7439 VL - 7 IS - 1 SP - 24 EP - 30 PB - Science Publishing Group ER - TY - JOUR A1 - Yuwono, Steve A1 - Schwung, Andreas A1 - Schwung, Dorothea T1 - Integrating Deep Model-Based Learning With Modular State-Based Stackelberg Games for Self-Optimizing Distributed Production Systems JF - IEEE Transactions on Cybernetics KW - Intelligente Fertigung KW - Optimierung KW - Maschinelles Lernen KW - Deep Learning KW - Stackelberg-Duopol Y1 - 2025 U6 - https://doi.org/10.1109/TCYB.2025.3610707 SN - 2168-2267 PB - Institute of Electrical and Electronics Engineers (IEEE) ER - TY - JOUR A1 - Naraparaju, R. A1 - Lau, H. A1 - Lange, Martin A1 - Fischer, Christian A1 - Kramer, D. A1 - Schulz, U. A1 - Weber, Konradin T1 - Integrated testing approach using a customized micro turbine for a volcanic ash and CMAS related degradation study of thermal barrier coatings JF - Surface and Coatings Technology KW - Luftreinhaltung Y1 - 2018 U6 - https://doi.org/10.1016/j.surfcoat.2018.01.030 SN - 0257-8972 VL - 337 SP - 198 EP - 208 PB - Elsevier ER - TY - CHAP A1 - Marzi, Karoline A1 - Klapperich, Holger A1 - Huldtgren, Alina ED - Stolze, Markus ED - Loch, Frieder ED - Baldauf, Matthias ED - Alt, Florian ED - Schneegrass, Christina ED - Kosch, Thomas ED - Hirzle, Teresa ED - Sadeghian, Shadan ED - Draxler, Fiona ED - Bektas, Kenan ED - Lohan, Katrin ED - Knierim, Pascal T1 - Insights on Older Adults’ Willingness, Motives and Experiences regarding Participation in HCI research T2 - MuC '23: Proceedings of Mensch und Computer 2023, Rapperswil Switzerland, September 3 - 6, 2023 N2 - User-centered and Participatory Design approaches have become widespread within HCI, also when designing digital media for older adults. These methodologies are seen as crucial to adapt technology design to older people's needs and increase their acceptance of digital technology. Nevertheless, it is often difficult to reach a diverse group of older people, for instance, people with limited technology skills, limited mobility, or cognitive issues. In addition, gerontologists criticized lately how older people's participation unfolds in technology design projects, e.g. that people are pushed into the role of users. Little is known about the motivations and needs of older adults regarding their participation in HCI research. To close this gap, we conducted an online survey (N=46) and semi-structured interviews (N=8) focusing on motivations, willingness and experiences regarding participation. Results show that people are generally willing to participate due to interest in the topic, learning new things and social bonding. However, despite the conceptions within HCI that long-term engagement is crucial within participatory design, older people in the study preferred less commitment and more open formats. Y1 - 2023 SN - 979-8-4007-0771-1 U6 - https://doi.org/10.1145/3603555.3608540 SP - 432 EP - 436 PB - Association for Computing Machinery CY - New York ER - TY - CHAP A1 - Schmitt, Lothar M. A1 - Herder, Jens A1 - Bhalla, Subhash ED - Gorayska, Barbara ED - Nehaniv, Chrystopher L. ED - Marsh, Jonathon P. T1 - Information Retrieval and Database Architecture for Conventional Japanese Character Dictionaries T2 - Proceedings, Second International Conference on Cognitive Technology N2 - The cycle of abstraction-reconstruction which occurs as a fundamental principle in the development of culture and in cognitive processes is described and analyzed. This approach leads to recognition of boundary conditions for and directions of probable development of cognitive tools. It is shown how the transition from a conventional Japanese-English character dictionary to a multi-dimensional language database is an instance of such an abstraction-reconstruction cycle. The different phases of the design of a multi-dimensional language database based upon different computer software technologies are properly placed in this cycle. The methods used include the use of UNIX software tools, classical database methods as-well-as the use of search engines based upon full text search in this process. Several directions of application and extension for a multi-dimensional language database are discussed from the general point of view of an abstraction-reconstruction cycle. KW - abstraction-reconstruction cycle KW - database KW - dictionary KW - hypertext, search engine KW - retrieval methods KW - UNIX Y1 - 1997 SN - 0-8186-8084-9 SP - 200 EP - 217 PB - IEEE CY - Los Alamitos ER - TY - JOUR A1 - Gille, Christoph A1 - Krüger, Christine A1 - Wéber, Júlia T1 - Influences of the far right on social work in Germany: systematic attacks and daily shifts JF - European Journal of Social Work T2 - Einflussnahmen der extremen Rechten auf die Soziale Arbeit in Deutschland: Systematische Angriffe und alltägliche Verschiebungen KW - Rechtsradikalismus KW - Sozialarbeit KW - FBSK_Webseite Y1 - 2022 U6 - https://doi.org/10.1080/13691457.2022.2063810 SN - 1369-1457 VL - 26 IS - 3 SP - 561 EP - 574 PB - Taylor & Francis ER - TY - JOUR A1 - Winter, Franziska Luise A1 - Diehl, Patrick A1 - Telaar, Pascal A1 - Watermann, Clara Maria A1 - Kaluza, Stefan A1 - Muhler, Martin A1 - Apfel, Ulf-Peter A1 - Zeidler-Fandrich, Barbara T1 - Influence of the catalyst precursor for cobalt on activated carbon applied in ammonia decomposition JF - Catalysis Today N2 - Ammonia is a key compound for storing and transporting green hydrogen. However, the efficient release of stored hydrogen through thermocatalytic ammonia decomposition is achievable only at temperatures around 600 °C, particularly with non-noble metal-based catalysts, which prove to be both ecologically and economically more feasible. In this study, electrically conductive activated carbon was selected as the catalyst support, chosen specifically for its suitability in achieving more energy-efficient direct reactor heating through the ohmic resistance of the catalysts. Cobalt salts were wet impregnated on activated carbon investigating the influence of different precursors (cobalt nitrate and cobalt acetate) and pyrolysis temperatures (400 °C and 600 °C) under N2 flow on the cobalt particle size and the incorporation of cobalt into the carbon matrix. TEM imaging and CO-chemisorption revealed well dispersed cobalt particles with sizes below 10 nm for the catalysts synthesized from the cobalt nitrate precursor. On the other hand, cobalt acetate led to about nine times larger Co agglomerates, which were partially detached from the carbon matrix. Moreover, this substantial difference in the Co particle size results in a significantly higher ammonia conversion for cobalt nitrate-based catalysts, achieving 94 % of ammonia conversion at 600 °C. Furthermore, the long-term stability test of the cobalt nitrate-based catalyst resulted in a slight deactivation of only 2 % ammonia conversion at 500 °C. KW - Katalyse KW - Ammoniak KW - Grüner Wasserstoff KW - Ammonia decomposition KW - Carbon supported cobalt KW - Synthesis design KW - Cobalt acetate KW - Cobalt nitrate KW - Resistance heating Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-46600 SN - 0920-5861 VL - 429 PB - Elsevier ER - TY - JOUR A1 - Petit, Y. A1 - Henin, S. A1 - Kasparian, J. A1 - Wolf, J. P. A1 - Rohwetter, P. A1 - Stelmaszczyk, K. A1 - Hao, Z. Q. A1 - Nakaema, W. M. A1 - Wöste, L. A1 - Vogel, A. A1 - Pohl, T. A1 - Weber, Konradin T1 - Influence of pulse duration, energy, and focusing on laser-assisted water condensation JF - Applied Physics Letters N2 - We investigate the influence of laser parameters on laser-assisted water condensation in the atmosphere. Pulse energy is the most critical parameter. Nanoparticle generation depends linearly on energy beyond the filamentation threshold. Shorter pulses are more efficient than longer ones with saturation at ∼1.5 ps. Multifilamenting beams appear more efficient than strongly focused ones in triggering the condensation and growth of submicronic particles, while polarization has a negligible influence on the process. The data suggest that the initiation of laser-assisted condensation relies on the photodissociation of the air molecules rather than on their photoionization. KW - Luftreinhaltung Y1 - 2011 U6 - https://doi.org/10.1063/1.3546172 SN - 0003-6951 VL - 98 IS - 4 PB - AIP Publishing ER - TY - JOUR A1 - Himmelein, Hendrik A1 - von Berg, Markus A1 - Pörschmann, Christoph A1 - Steffens, Jochen T1 - Influence of mental effort on sound evaluations in virtual and real experimental environments JF - Frontiers in Virtual Reality N2 - Psychoacoustic research increasingly relies on virtual reality (VR) to account for the complexity of acoustic scenarios and enhance the ecological validity of laboratory findings. However, recent studies suggest that virtual environments can alter mental effort compared to real-world settings, for example, through increased perceptual complexity which in turn may affect auditory perception.This could bias experimental outcomes and compromise the ecological validity of studies conducted in VR. To investigate this, a 2 × 2 between-subjects experiment was conducted to assess whether VR environments increase mental effort and thereby influence auditory perception. A real office environment was visually reconstructed in Unity and presented to the participants via a head-mounted display (HMD) and compared to its real counterpart. Participants in both environments were asked to retrospectively rate the loudness and unpleasantness of dynamically rendered binaural office noise scenarios presented via headphones and to report perceived sound sources. Moreover, participants were divided into two groups to induce different levels of mental effort. One group was asked to listen only to the sounds, while the other performed the Stroop Color-Word interference test in parallel. The results show no significant difference in the overall induced mental effort between environment conditions. Furthermore, performing the Stroop test had an effect on loudness and unpleasantness that was mediated by subjective effort. The results also suggest that auditory jugment depend primarily on individual sound properties, regardless of the visual environment. KW - Psychoakustik KW - Virtuelle Realität KW - Lautwahrnehmung KW - Head-mounted Display Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-57985 SN - 2673-4192 VL - 6 PB - Frontiers Media SA ER - TY - JOUR A1 - Vansteenkiste, A. A1 - De Baerdemaeker, J. A1 - Chou, Kang Wei A1 - Stoll, H. A1 - Curcic, Michael A1 - Tyliszczak, T. A1 - Woltersdorf, G. A1 - Back, Christian H. A1 - Schütz, G. A1 - Van Waeyenberge, B. T1 - Influence of domain wall pinning on the dynamic behavior of magnetic vortex structures: Time-resolved scanning x-ray transmission microscopy in NiFe thin film structures JF - Physical Review B Y1 - 2008 U6 - https://doi.org/10.1103/PhysRevB.77.144420 SN - 1098-0121 VL - 77 IS - 14 PB - American Physical Society ER -