@article{Levina2021, author = {Levina, Olga}, title = {Von Ethik zu Recht : Der AI Act und seine Bedeutung f{\"u}r die Gestaltung von algorithmischen Systemen}, series = {Informatik aktuell}, journal = {Informatik aktuell}, publisher = {Alkmene Verlag}, issn = {2511-7564}, year = {2021}, language = {de} } @article{WhiskerdKoertgeJuergensetal.2020, author = {Whiskerd, Nicholas and K{\"o}rtge, Nicklas and J{\"u}rgens, Kris and Ezennaya-Gomez, Salatiel and Vielhauer, Claus and Dittmann, Jana and Hildebrandt, Mario}, title = {Keystroke biometrics in the encrypted domain: a first study on search suggestion functions of web search engines}, series = {EURASIP Journal on Information Security}, journal = {EURASIP Journal on Information Security}, number = {2020:2}, publisher = {Springer}, doi = {10.1186/s13635-020-0100-8}, year = {2020}, language = {en} } @article{PilgermannBocklischCreutzburg2020, author = {Pilgermann, Michael and Bocklisch, Thomas and Creutzburg, Reiner}, title = {Conception and implementation of a course for professional training and education in the field of IoT and smart home security}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2020.3.MOBMU-277}, pages = {277-1 -- 277-8}, year = {2020}, language = {en} } @article{PilgermannWerthCreutzburg2020, author = {Pilgermann, Michael and Werth, S{\"o}ren and Creutzburg, Reiner}, title = {Towards sector specific security operation}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2020.3.MOBMU-254}, pages = {254-1 -- 254-10}, year = {2020}, language = {en} } @article{FitzScheegScheeg2022, author = {Fitz, Lukas R. G. and Scheeg, Michaela and Scheeg, Jochen}, title = {Amplifying Human Factors in the Inquiry of SMEs' Needs in Digitalization Collaborations with External Service Providers}, series = {Procedia Computer Science}, volume = {200}, journal = {Procedia Computer Science}, publisher = {Elsevier}, issn = {1877-0509}, doi = {10.1016/j.procs.2022.01.257}, pages = {595 -- 601}, year = {2022}, language = {en} } @article{VogelWoelferRamirezDiazetal.2020, author = {Vogel, Sven and W{\"o}lfer, Christian and Ramirez-Diaz, Diego and Flassig, Robert and Sundmacher, Kai and Schwille, Petra}, title = {Symmetry Breaking and Emergence of Directional Flows in Minimal Actomyosin Cortices}, series = {Cells}, journal = {Cells}, publisher = {MDPI}, doi = {10.3390/cells9061432}, pages = {1 -- 10}, year = {2020}, abstract = {Cortical actomyosin flows, among other mechanisms, scale up spontaneous symmetry breaking and thus play pivotal roles in cell differentiation, division, and motility. According to many model systems, myosin motor-induced local contractions of initially isotropic actomyosin cortices are nucleation points for generating cortical flows. However, the positive feedback mechanisms by which spontaneous contractions can be amplified towards large-scale directed flows remain mostly speculative. To investigate such a process on spherical surfaces, we reconstituted and confined initially isotropic minimal actomyosin cortices to the interfaces of emulsion droplets. The presence of ATP leads to myosin-induced local contractions that self-organize and amplify into directed large-scale actomyosin flows. By combining our experiments with theory, we found that the feedback mechanism leading to a coordinated directional motion of actomyosin clusters can be described as asymmetric cluster vibrations, caused by intrinsic non-isotropic ATP consumption with spatial confinement. We identified fingerprints of vibrational states as the basis of directed motions by tracking individual actomyosin clusters. These vibrations may represent a generic key driver of directed actomyosin flows under spatial confinement in vitro and in living systems.}, language = {en} } @article{GoschinVogelFlassig2022, author = {Goschin, Tobias and Vogel, Mathias and Flassig, Robert}, title = {Energy Technologies For Decarbonizing The Steel Processing Industry - A Numerical Study}, series = {IFAC-PapersOnLine}, volume = {55}, journal = {IFAC-PapersOnLine}, number = {9}, publisher = {Elsevier}, doi = {https://doi.org/10.1016/j.ifacol.2022.07.001}, pages = {1 -- 5}, year = {2022}, abstract = {This study analyzes approaches to decarbonize the energy supply of the secondary steel processing industry. Therefore, real data from a secondary steel production company is used in combination with state-of-the art low carbon energy supply technologies. Also, the use of waste heat from a pusher furnace for process integration is considered. The developed temporal process model allows holistic optimizing and expanding the steel making process system regarding techno-economic criteria. As we show, implementing the annual heat demand of a municipality shows that a nearly 100 \% self-sufficient heat supply is possible.}, language = {en} } @article{TrittelKloppHarthetal.2022, author = {Trittel, Torsten and Klopp, Christoph and Harth, Kirsten and Stannarius, Ralf}, title = {Stability and Rupture of Liquid Crystal Bridges under Microgravity}, series = {Crystals}, volume = {12}, journal = {Crystals}, number = {8}, publisher = {MDPI}, doi = {https://doi.org/10.3390/cryst12081092}, pages = {16}, year = {2022}, language = {en} } @article{WeberSteinPilgermannetal.2023, author = {Weber, Simon B. and Stein, Stefan and Pilgermann, Michael and Schrader, Thomas}, title = {Attack Detection for Medical Cyber-Physical Systems - A Systematic Literature Review}, series = {IEEE Access}, journal = {IEEE Access}, number = {11}, publisher = {IEEE}, doi = {10.1109/ACCESS.2023.3270225}, pages = {41796 -- 41815}, year = {2023}, abstract = {The threat situation due to cyber attacks in hospitals is emerging and patient life is at risk. One significant source of potential vulnerabilities is medical cyber-physical systems (MCPS). Detecting intrusions in this environment faces challenges different from other domains, mainly due to the heterogeneity of devices, the diversity of connectivity types, and the variety of terminology. To summarize existing results, we conducted a structured literature review (SLR) following the guidelines of Kitchenham et al. for SLRs in software engineering. We developed six research questions regarding detection approach, detection location, included features, adversarial focus, utilized datasets, and intrusion prevention. We identified that most researchers focused on an anomaly-based detection approach at the network layer. The primary focus was on the detection of malicious insiders. While several researchers used publicly available datasets for training and testing their algorithms, the lack of suitable datasets resulted in the development of testbeds consisting of various medical devices. Based on the results, we formulated five future research topics. First, the special conditions of hospital networks, the MCPS deployed within them, and the contrasts to other IT and OT environments should be examined. Thereupon, MCPS-specific datasets should be created that allow researchers to address the health domain's unique requirements and possibilities. At the same time, endeavors aimed at standardization in this area should be supported and expanded. Moreover, the use of medical context for attack detection should be further explored. Last but not least, efforts for MCPS-tailored intrusion prevention should be intensified. This way, the emerging threat landscape can be addressed, IT security in hospitals can be improved, and patient health can be protected.}, language = {en} } @article{KollathHajduDegenetal.2025, author = {Koll{\´a}th, Zolt{\´a}n and Hajdu, Tam{\´a}s and Degen, Tobias and Jechow, Andreas and Sztakovics, J{\´a}nos}, title = {Conversion between measurement units used for night sky quality assessment with multispectral (RGB) cameras}, series = {Journal of Quantitative Spectroscopy and Radiative Transfer}, volume = {347}, journal = {Journal of Quantitative Spectroscopy and Radiative Transfer}, publisher = {Elsevier}, doi = {10.1016/j.jqsrt.2025.109636}, pages = {1 -- 10}, year = {2025}, abstract = {In recent years, many studies have shown that light pollution adversely affects wildlife, ecosystems, and human well-being. To assess and mitigate these impacts, it is crucial that measurements of night sky quality are reliable and comparable across sites and instruments. However, the lack of standardised night sky brightness metrology and the use of a wide variety of measurement instruments with varying spectral responsivity and field-specific measurement units hinder meaningful comparison. We collected night sky spectra from 44 nights at dark locations (existing and proposed dark sky parks). Based on this observational dataset, we created a larger random set of spectra. These data served to fit conversion parameters for a wide variety of units. We demonstrate that RGB cameras, when used as multichannel measuring devices, enable the retrieval of measurements that facilitate conversions between different units. Furthermore, even airglow can be quantified from a given measurement, enabling the determination of oxygen and sodium emission line contributions. Since this contribution is not negligible, quantitative measurements of its magnitude are crucial for accurately assessing light pollution at dark-sky sites. Using our spectral measurement database, we constructed the most probable transformation from the cameras' R, G, and B channel 𝑑𝑠𝑢 values to other units, such as the astronomical Bessel V band magnitudes. The unit conversion formulas provided in this paper are valid for mildly polluted sites (existing and proposed dark sky places), in the 21-22 magV∕arcsec2 range.}, language = {de} } @article{SchumannStoilovaBortolettoetal.2025, author = {Schumann, Sophia and Stoilova, Velizara and Bortoletto, Enrico and Piva, Elisabetta and Pacchini, Sara and Mozzi, Gloria and Jechow, Andreas and Marion, Andrea and Bertotto, Daniela and Erlandson, Ann and H{\"o}lker, Franz and Greenberg, Larry and Santovito, Gianfranco}, title = {Impact of artificial light at night (ALAN) on cardiac function and acute oxidative stress physiology in migratory brown trout smolts}, series = {Environmental Pollution}, journal = {Environmental Pollution}, number = {381}, publisher = {Elsevier}, doi = {10.1016/j.envpol.2025.126593}, pages = {1 -- 9}, year = {2025}, abstract = {Light pollution poses significant ecological challenges for nocturnal animals reliant on natural light for migration, orientation, and circadian rhythms. The physiological effects of abrupt exposure to artificial light at night (ALAN) on migratory fish, such as the light experienced passing near illuminated infrastructures, remain poorly understood. This study investigates the physiological responses of brown trout (Salmo trutta) smolts to low-intensity (0.02 lx) and short-term (30 s) ALAN, simulating nocturnal migration light conditions near illuminated bridges. To evaluate the influence of social dynamics, trout were tested individually (solitary) or in groups of six. Using continuous cardiac monitoring with data storage tags, alongside analyses of oxidative stress markers and adenylate kinase (AK) activity in the heart, we identified distinct patterns of physiological responses. Solitary fish exhibited significant heart rate variability (HRV) increases following repeated ALAN exposure, suggesting impaired physiological regulation under repeated ALAN exposure. In contrast, trout in groups displayed consistently lower HRV over the entire 90-min experiment, implying that social dynamics likely influenced a sustained oxidative stress response, corroborated by increased AK activity. Oxidative stress markers further reflected social effects, with significant upregulation of key antioxidant enzymes (sod1, sod2, gpx1, gpx4) and elevated lipid peroxidation, identifying lipids as primary oxidative targets. The observed divergence between superoxide dismutase (SOD) activity and sod gene expression suggests adaptive post-transcriptional regulation to maintain redox balance under combined environmental and social stress. These findings reveal that social dynamics under ALAN can amplify physiological stress, potentially affecting migratory outcomes.}, language = {en} } @article{FitzScheeg2025, author = {Fitz, Lukas R. G. and Scheeg, Jochen}, title = {Alternative digital platforms: comparative analysis through the lens of Corporate Aikido}, series = {Information Systems and e-Business Management}, journal = {Information Systems and e-Business Management}, publisher = {Springer}, doi = {10.1007/s10257-025-00703-8}, pages = {1 -- 22}, year = {2025}, abstract = {Competing with dominant players in the digital platform (DP) economy is an increasingly complex and expensive endeavor for alternative digital platform (ADP) providers trying to disrupt established platform ecosystems. Nevertheless, ADPs position themselves deliberately in the competitive space of large competitors, targeting customer groups whose values and mindsets differ from mainstream DPs. Although there are many examples to find in practice, the variety of ADPs across different DP ecosystems and industries, especially in regards of strategic objectives, directions and characteristics, has not been researched in-depth yet. Based on a systematic, practice-based artifact review, this paper analyses and compares 105 ADPs in the competitive space of dominant DP ecosystem players. The study utilizes the theory of Corporate Aikido as an analytical framework, mapping the strategic elements of overthrowing established value propositions and turning a competitors' strengths into weaknesses. Our findings indicate that privacy- and security-awareness, empowerment and inclusivity, premium quality and curation, open source and free access, uncensored, transparent and decentralized platforms as well as ecological and climate-friendly offers shape the landscape of alternative approaches in today's DP economy. The results are subsequently discussed, yielding managerial implications and future opportunities for DP research.}, language = {en} } @article{FroschLindauer2025, author = {Frosch, Katharina and Lindauer, Friederike}, title = {Learning With Short Bursts: How Effectively Can We Build Competencies in Climate Change-Related Areas Based on Microlearning?}, series = {European Journal of Education}, volume = {60}, journal = {European Journal of Education}, number = {2}, publisher = {Wiley}, doi = {10.1111/ejed.70088}, pages = {1 -- 17}, year = {2025}, abstract = {The study examines the effectiveness of microlearning in developing the capacity to address climate change and adapt to environmental challenges. Conducted as an online field experiment with 140 participants, the study focused on the impacts of smartphone use as an illustrative learning domain for education in climate change-related areas. Using a pre-post research design and simultaneous equation models, the study found improvements in knowledge retention, with a median increase of 38\%. The results indicated that the brief microlearning units also promoted sustainability action competencies, such as confidence in one's influence and willingness to act sustainably. This suggests that higher-order learning processes were also triggered, although to a much lesser extent. Furthermore, learner satisfaction was identified as a mediating variable for these positive outcomes. The study concludes that short bursts of knowledge delivered through microlearning activities can be used alongside traditional training methods to build the critical skills needed for initiatives such as the EU Green Deal.}, language = {en} } @article{KalinkatJechowSchroeretal.2025, author = {Kalinkat, Gregor and Jechow, Andreas and Schroer, Sibylle and H{\"o}lker, Franz}, title = {Nocturnal pandas: conservation umbrellas protecting nocturnal biodiversity}, series = {Trends in Ecology \& Evolution}, volume = {40}, journal = {Trends in Ecology \& Evolution}, number = {8}, publisher = {Elsevier}, doi = {10.1016/j.tree.2025.05.006}, pages = {736 -- 739}, year = {2025}, abstract = {Light pollution is an emerging ecological threat. To mitigate its negative consequences, creative inter- and transdisciplinary solutions and societal interactions are needed. To this end, we introduce nocturnal umbrella species representative of light-sensitive biodiversity whose protection will safeguard vital ecosystem services and a wide range of co-occurring species.}, language = {en} } @article{FitzScheeg2025, author = {Fitz, Lukas R. G. and Scheeg, Jochen}, title = {Coping Practices of Small- and Medium-Sized Enterprises Facing Power Asymmetry in Digital Platform Business}, series = {Strategic Change}, journal = {Strategic Change}, publisher = {Wiley}, doi = {10.1002/jsc.2657}, pages = {1 -- 21}, year = {2025}, abstract = {Digital platform (DP) enterprises have risen to the top of the global economy by inverting traditional business models. They earn money through matchmaking, transaction facilitation, and efficient orchestration of other stakeholders' resources. Small- and medium-sized enterprises (SMEs) play a decisive role in this success story: they offer products and services on many leading DPs and thereby feed platform networks as sellers and suppliers. On the other hand, while DPs enable SMEs to reach new customers and outsource costly managerial tasks, many SMEs struggle with the negative consequences of asymmetric power dynamics and dependency risks in platform business. This paper analyzes 14 cases of SMEs that face power asymmetry as DP value providers, unraveling challenges encountered and coping practices employed in this situation. The findings reveal that power asymmetry between dominant DPs and SMEs creates significant challenges, including exploitative relationships, loss of autonomy, surveillance pressures, and devaluation of SME contributions, while SMEs cope through disintermediation, multi-homing, individual resistance tactics, and striving for more equitable DP models. Moreover, three relationality types are identified: DPs being SMEs' "partners," "tools," and "necessary evil." This article offers a new perspective on boundaries of SME strategies in the DP economy and contributes with empirical insights to the advancing field of entrepreneurial platform research.}, language = {en} } @article{VollmerEberhardt2024, author = {Vollmer, Michael and Eberhardt, Wolfgang}, title = {Ein einfaches Modell f{\"u}r die Vorhersage von CO2 Konzentrationen in der Atmosph{\"a}re in Abh{\"a}ngigkeit von globalen CO2 Emissionen}, series = {PhyDid B, Didaktik der Physik, Beitr{\"a}ge zur DPG-Fr{\"u}hjahrstagung}, volume = {1}, journal = {PhyDid B, Didaktik der Physik, Beitr{\"a}ge zur DPG-Fr{\"u}hjahrstagung}, number = {1}, publisher = {FU Berlin}, organization = {Fachverband Didaktik der Physik}, issn = {2191-379X}, pages = {379 -- 388}, year = {2024}, abstract = {Es wird das vielleicht einfachst m{\"o}gliche Modell vorgestellt, mit dem zeitabh{\"a}ngige CO2 Konzent-rationen c(t) in der Atmosph{\"a}re ausgehend von verschiedenen globalen Emissionsszenarien f{\"u}r CO2berechnet werden. Dazu wird eine einzelne inhomogene lineare Differenzialgleichung 1. Ordnung hergeleitet, deren Parameter sich aus den quantitativen Daten des global carbon project sowie Mauna Loa Daten f{\"u}r CO2 Konzentrationen errechnen. Das Modell wird erstens getestet am Zeitraum 1960 bis 2020 mit vergleichsweise guter quantitativer {\"U}bereinstimmung zu Messdaten. Zweitens wird f{\"u}r zwei typische IPCC Emissions-Szenarien ein Vergleich der Modellvorhersagen mit denen der kom-plexen IPCC Earth-System-Klimamodelle diskutiert mit qualitativer {\"U}bereinstimmung des zeitli-chen Verlaufs. Drittens werden Ergebnisse einiger ausgew{\"a}hlter neuer Emissionsszenarien pr{\"a}sen-tiert. Ungeachtet einiger Abweichungen zu komplexeren Klimamodellen zeichnet sich unser Mo-dell durch zwei wichtige Vorteile f{\"u}r die Lehre aus. Zum einen ist es sehr einfach f{\"u}r Studierende und begabte Sch{\"u}ler nutzbar, da die erforderliche L{\"o}sung der Differentialgleichung bereits mit han-dels{\"u}blicher Tabellenkalkulationssoftware wie z.B. Excel programmiert werden kann. Dadurch ge-stattet es zum anderen auch sehr einfach, den zeitlichen Verlauf von Emissionsszenarien zu ver{\"a}n-dern und innerhalb weniger Sekunden Ver{\"a}nderungen aufgrund ge{\"a}nderter Eingaben zu berechnen. Insofern eignet sich das Modell sehr gut als Einstieg in das Thema Klimamodellierung in einf{\"u}hren-den Hochschulvorlesungen zum Themenbereich Kohlenstoffkreislauf und Klimawandel. In der Schule kann es gegen Ende der Sekundarstufe 2 beispielsweise im Projektunterricht zum Themen-komplex Nachhaltigkeit in Physik und/oder Mathematik eingesetzt werden}, language = {de} } @article{KloppTrittelStannarius2024, author = {Klopp, Christoph and Trittel, Torsten and Stannarius, Ralf}, title = {Coarsening of quasi two-dimensional emulsions formed by islands in free-standing smectic films}, series = {ChemPhysChem}, volume = {25}, journal = {ChemPhysChem}, number = {12}, publisher = {Wiley}, doi = {10.1002/cphc.202400166}, pages = {1 -- 12}, year = {2024}, abstract = {We study the coarsening behavior of assemblies of islands on smectic A freely suspended films in ISS microgravity experiments. The islands can be regarded as liquid inclusions in a two-dimensional fluid in analogy to liquid droplets of the discontinuous phase of an emulsion. The coarsening is effectuated by two processes, predominantly by island coalescence, but to some extend also by Ostwald ripening, whereby large islands grow at the expense of surrounding smaller ones. A peculiarity of this system is that the continuous and the discontinuous phases consist of the same material. We determine the dynamics, analyze the self-similar aging of the island size distribution and discuss characteristic exponents of the mean island growth.}, language = {en} } @article{Vollmer2024, author = {Vollmer, Michael}, title = {Limitations of the eye and how to overcome them}, series = {Journal of Physics: Conference Series}, volume = {2750}, journal = {Journal of Physics: Conference Series}, number = {1}, doi = {10.1088/1742-6596/2750/1/012001}, pages = {1 -- 10}, year = {2024}, abstract = {Human eyes have spatial, temporal, and spectral limitations which impose constraints on our perception. With appropriate optical devices and cameras, the limitations can be easily overcome. As a consequence, a huge variety of physical phenomena can be made accessible for teaching.}, language = {en} } @article{PuzyrevTorstenHarthetal.2024, author = {Puzyrev, Dmitry and Torsten, Torsten and Harth, Kirsten and Stannarius, Ralf}, title = {Cooling of a granular gas mixture in microgravity}, series = {npj microgravity}, volume = {10}, journal = {npj microgravity}, number = {1}, publisher = {Springer}, address = {Brandenburg an der Havel}, doi = {10.1038/s41526-024-00369-5}, pages = {1 -- 9}, year = {2024}, abstract = {Granular gases are fascinating non-equilibrium systems with interesting features such as spontaneous clustering and non-Gaussian velocity distributions. Mixtures of different components represent a much more natural composition than monodisperse ensembles but attracted comparably little attention so far. We present the observation and characterization of a mixture of rod-like particles with different sizes and masses in a drop tower experiment. Kinetic energy decay rates during granular cooling and collision rates were determined and Haff's law for homogeneous granular cooling was confirmed. Thereby, energy equipartition between the mixture components and between individual degrees of freedom is violated. Heavier particles keep a slightly higher average kinetic energy than lighter ones. Experimental results are supported by numerical simulations.}, language = {de} } @article{TrittelPuzyrevHarthetal.2024, author = {Trittel, Torsten and Puzyrev, Dmitry and Harth, Kirsten and Stannarius, Ralf}, title = {Rotational and translational motions in a homogeneously cooling granular gas}, series = {npj microgravity}, volume = {10}, journal = {npj microgravity}, number = {1}, publisher = {Springer}, doi = {10.1038/s41526-024-00420-5}, pages = {1 -- 6}, year = {2024}, abstract = {A granular gas composed of monodisperse spherical particles was studied in microgravity experiments in a drop tower. Translations and rotations of the particles were extracted from optical video data. Equipartition is violated, the rotational degrees of freedom were excited only to roughly 2/3 of the translational ones. After stopping the mechanical excitation, we observed granular cooling of the ensemble for a period of three times the Haff time, where the kinetic energy dropped to about 5\% of its initial value. The cooling rates of all observable degrees of freedom were comparable, and the ratio of rotational and translational kinetic energies fluctuated around a constant value. The distributions of translational and rotational velocity components showed slight but systematic deviations from Gaussians at the start of cooling.}, language = {en} }