@article{RizunRevinaEdelmann2025, author = {Rizun, Nina and Revina, Aleksandra and Edelmann, Noella}, title = {Text analytics for co-creation in public sector organizations: a literature review-based research framework}, series = {Artificial Intelligence Review}, journal = {Artificial Intelligence Review}, doi = {10.1007/s10462-025-11112-1}, pages = {1 -- 45}, year = {2025}, abstract = {The public sector faces considerable challenges that stem from increasing external and internal demands, the need for diverse and complex services, and citizens' lack of satisfaction and trust in public sector organisations (PSOs). An alternative to traditional public service delivery is the co-creation of public services. Data analytics has been fueled by the availability of immense amounts of data, including textual data, and techniques to analyze data, so it has immense potential to foster data-driven solutions for the public sector. In the paper, we systematically review the existing literature on the application of Text Analytics (TA) techniques on textual data that can support public service co-creation. In this review, we identify the TA techniques, the public services and the co-creation phase they support, as well as envisioned public values for the stakeholder groups. On the basis of the analysis, we develop a Research Framework that helps to structure the TA-enabled co-creation process in PSOs, increases awareness among public sector organizations and stakeholders on the significant potential of TA in creating value, and provides scholars with some avenues for further research.}, language = {en} } @article{RizunRevinaMeister2021, author = {Rizun, Nina and Revina, Aleksandra and Meister, Vera G.}, title = {Assessing business process complexity based on textual data: Evidence from ITIL IT ticket processing}, series = {Business Process Management Journal}, volume = {27}, journal = {Business Process Management Journal}, number = {7}, publisher = {Emerald}, issn = {1758-4116}, doi = {10.1108/BPMJ-04-2021-0217}, pages = {1966 -- 1998}, year = {2021}, language = {en} } @article{RojekIslamHartmannetal.2021, author = {Rojek, Lukasz and Islam, Saiful and Hartmann, Michael and Creutzburg, Reiner}, title = {IoT-Based Real-Time Monitoring System for a Smart Energy House}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2021.3.MOBMU-038}, pages = {38-1 -- 38-10}, year = {2021}, language = {en} } @article{RudenkoGaponenkoLitvinovetal.2020, author = {Rudenko, Maryia and Gaponenko, Nikolai and Litvinov, Vladimir and Ermachikhin, Alexander and Chubenko, Eugene and Borisenko, Victor and Mukhin, Nikolay and Radyush, Yuriy and Tumarkin, Andrey and Gagarin, Alexander}, title = {Structural Dependent Eu3+ Luminescence, Photoelectric and Hysteresis Effects in Porous Strontium Titanate}, series = {Materials}, volume = {13}, journal = {Materials}, number = {24}, publisher = {MDPI}, doi = {10.3390/ma13245767}, year = {2020}, language = {en} } @article{RuzankinaMukhinMermouletal.2022, author = {Ruzankina, Iuliia and Mukhin, Nikolay and Mermoul, Ali and Parfenov, Vadim and Fron, Eduard and Ferrini, Gabriele}, title = {Surface optical sensitivity enhanced by a single dielectric microsphere}, series = {Optics Express}, volume = {30}, journal = {Optics Express}, number = {24}, publisher = {Optica}, pages = {43021 -- 43036}, year = {2022}, abstract = {Single dielectric microspheres can manipulate light focusing and collection to enhance optical interaction with surfaces. To demonstrate this principle, we experimentally investigate the enhancement of the Raman signal collected by a single dielectric microsphere, with a radius much larger than the exciting laser spot size, residing on the sample surface. The absolute microsphere-assisted Raman signal from a single graphene layer measured in air is more than a factor of two higher than that obtained with a high numerical aperture objective. Results from Mie's theory are used to benchmark numerical simulations and an analytical model to describe the isolated microsphere focusing properties. The analytical model and the numerical simulations justify the Raman signal enhancement measured in the microsphere-assisted Raman spectroscopy experiments.}, language = {en} } @article{Sasaki2021, author = {Sasaki, Felix}, title = {K{\"u}nstliche Intelligenz in der Ausbildung von Wissensarbeiterinnen und Wissensarbeitern}, series = {API : Ausbilden, Publizieren, Informieren - studentisches Magazin der HAW Hamburg}, volume = {2}, journal = {API : Ausbilden, Publizieren, Informieren - studentisches Magazin der HAW Hamburg}, number = {1}, publisher = {Hamburg University Press}, issn = {2699-6693}, doi = {10.15460/apimagazin.2021.2.1.65}, pages = {1 -- 16}, year = {2021}, language = {de} } @article{SataStannariusPuzyrev2025, author = {Sata, Sai Preetham and Stannarius, Ralf and Puzyrev, Dmitry}, title = {Criteria for dynamical clustering in permanently excited granular gases: comparison and estimation with machine learning approaches}, series = {Granular Matter}, volume = {27}, journal = {Granular Matter}, number = {4}, publisher = {Springer}, doi = {10.1007/s10035-025-01560-5}, year = {2025}, abstract = {When granular gases in microgravity are continuously excited mechanically, spatial inhomogeneities of the particle distribution can emerge. At a sufficiently large overall packing fraction, a significant share of particles tend to concentrate in strongly overpopulated regions, so-called clusters, far from the excitation sources. This dynamical clustering is caused by a complex balance between energy influx and dissipation. The mean number density of particles, the geometry of the container, and the excitation strength influence cluster formation. A quantification of clustering thresholds is not trivial. We generate 'synthetic' data sets by Discrete Element Method simulations of frictional spheres in a cuboid container and apply established criteria to classify the local packing fraction profiles. Machine learning approaches that predict dynamic clustering from known system parameters on the basis of classical test criteria areoposed and tested. It avoids the necessity of complex numerical simulations.}, language = {en} } @article{ScharfGuterdingHenetal.2025, author = {Scharf, Gili and Guterding, Daniel and Hen, Bar and Sarte, Paul M. and Ortiz, Brenden R. and Rozenberg, Gregory Kh. and Holder, Tobias and Wilson, Stephen D. and Jeschke, Harald O. and Ron, Alon}, title = {Pressure tuning of intrinsic and extrinsic sources to the anomalous Hall effect in CrGeTe3}, series = {Physical Review Research}, volume = {7}, journal = {Physical Review Research}, number = {1}, publisher = {American Physical Society}, doi = {10.1103/PhysRevResearch.7.013127}, pages = {1 -- 8}, year = {2025}, abstract = {The integrated Berry curvature is a geometric property that has dramatic implications for material properties. This study investigates the integrated Berry curvature and other contributions to the anomalous Hall effect in CrGeTe3 as a function of pressure. The anomalous Hall effect is absent in the insulating phase of CrGeTe3 and evolves with pressure in a domelike fashion as pressure is applied. The dome's edges are characterized by Fermi surface deformations, manifested as mixed electron and hole transport. We corroborate the presence of bipolar transport using ab initio calculations, which also predict a nonmonotonic behavior of the Berry curvature as a function of pressure. Quantitative discrepancies between our calculations and experimental results indicate that additional scattering mechanisms, which are also strongly tuned by pressure, contribute to the anomalous Hall effect in CrGeTe3.}, language = {en} } @article{Schnitzer2021, author = {Schnitzer, Julia}, title = {Generative Design For Creators - The Impact Of Data Driven Visualization And Processing In The Field Of Creative Business}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2021.3.MOBMU-022}, pages = {022-1 -- 022-6}, year = {2021}, language = {en} } @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{SchwarzSchwarzCreutzburg2021, author = {Schwarz, Franziska and Schwarz, Klaus and Creutzburg, Reiner}, title = {Improving Detection of Manipulated Passport Photos - Train- ing Course for Border Control Inspectors to Detect Morphed Facial Passport Photos - Part I: Introduction, State-of-the-Art and Preparatory Tests and Experiments}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2021.3.MOBMU-136}, pages = {136-1 -- 136-9}, year = {2021}, language = {en} } @article{SchwarzSchwarzCreutzburg2020, author = {Schwarz, Franziska and Schwarz, Klaus and Creutzburg, Reiner}, title = {New Methodology and Checklist of Wi-Fi Connected and App-Controlled IoT-Based Consumer Market Smart Home Devices}, 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-276}, pages = {276-1 -- 276-15}, year = {2020}, language = {en} } @article{SchwarzSchwarzCreutzburg2020, author = {Schwarz, Franziska and Schwarz, Klaus and Creutzburg, Reiner}, title = {Security and Privacy Investigation of Wi-Fi Connected and App-Controlled IoT-Based Consumer Market Smart Light Bulbs}, 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-275}, pages = {275-1 -- 275-11}, year = {2020}, language = {en} } @article{SchwarzSchwarzCreutzburg2020, author = {Schwarz, Franziska and Schwarz, Klaus and Creutzburg, Reiner}, title = {Conception of a Secure Remote Maintenance Procedure Using Dedicated Hardware}, 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-336}, pages = {336-1 -- 336-7}, year = {2020}, language = {en} } @article{SchwarzSchwarzFuchsetal.2021, author = {Schwarz, Franziska and Schwarz, Klaus and Fuchs, Daniel and Creutzburg, Reiner and Akopian, David}, title = {Firmware Vulnerability Analysis of Widely Used Low-Budget TP-Link Routers}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2021.3.MOBMU-135}, pages = {135-1 -- 135-11}, year = {2021}, language = {en} } @article{SchwarzCreutzburg2021, author = {Schwarz, Klaus and Creutzburg, Reiner}, title = {Design of Professional Laboratory Exercises for Effective State-of-the-Art OSINT Investigation Tools - Part 1: RiskIQ Passive-Total}, series = {Electronic imaging}, journal = {Electronic imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2021.3.MOBMU-043}, pages = {43-1 -- 43-7}, year = {2021}, language = {en} } @article{SchwarzCreutzburg2021, author = {Schwarz, Klaus and Creutzburg, Reiner}, title = {Design of Professional Laboratory Exercises for Effective State-of-the-Art OSINT Investigation Tools - Part 2: Censys}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, issn = {2470-1173}, doi = {10.2352/ISSN.2470-1173.2021.3.MOBMU-044}, pages = {44-1 -- 44-8}, year = {2021}, language = {en} } @article{SchwarzCreutzburg2021, author = {Schwarz, Klaus and Creutzburg, Reiner}, title = {Design of Professional Laboratory Exercises for Effective State-of-the-Art OSINT Investigation Tools - Part 3: Maltego}, series = {Electronic Imaging}, journal = {Electronic Imaging}, publisher = {Society for Imaging Science and Technology}, address = {Springfield, VA}, doi = {10.2352/ISSN.2470-1173.2021.3.MOBMU-045}, pages = {45-1 -- 45-23}, year = {2021}, language = {en} } @article{SchwarzSchwarzCreutzburg2020, author = {Schwarz, Klaus and Schwarz, Franziska and Creutzburg, Reiner}, title = {Conception and implementation of professional laboratory exercises in the field of open source intelligence (OSINT)}, 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-278}, pages = {278-1 -- 278-10}, year = {2020}, language = {en} } @article{StannariusWangPongoetal.2025, author = {Stannarius, Ralf and Wang, Jing and Pong{\´o}, Tivadar and Fan, Bo and B{\"o}rzs{\"o}nyi, Tam{\´a}s and Hidalgo, Ra{\´u}l Cruz}, title = {Forces on a sphere suspended in flowing granulate}, series = {EPJ Web of Conferences}, volume = {340}, journal = {EPJ Web of Conferences}, editor = {Alam, M. and Das, S.L. and Bose, M. and Murthy, T.G. and Chikkadi, V. and Singh, A. and Luding, S.}, publisher = {EDP Sciences}, doi = {10.1051/epjconf/202534002019}, year = {2025}, abstract = {We investigate the forces of flowing granular material on an obstacle. A sphere suspended in a discharging silo experiences both weight of the overlaying layers and drag of the surrounding moving grains. In experiments with frictional hard glass beads, the force on the obstacle was found to be practically flow-rate independent. In contrast, flow of nearly frictionless soft hydrogel spheres added drag forces which increased with the flow rate until reaching saturation at high flow speeds. The total force grew quadratically with the obstacle diameter in the soft, low friction material, while it grew much weaker, nearly linearly with the obstacle diameter, in the bed of hard, frictional glass spheres. In addition to the drag, obstacles embedded in the flowing hydrogel spheres experience a weight force from the top as if immersed in a hydrostatic pressure profile, but negligible counter-forces from below. In contrast, the frictional hard particles create a strong pressure gradient near the upper surface of the obstacle. Numerical simulations provide additional information that is difficult to access experimentally. They reproduce the experimental results and give hints for the origin of the different force contributions. The results have considerable practical importance for the discharge of storage containers with large objects suspended in flowing granular material.}, language = {en} } @article{SteinPilgermannSedlmayr2025, author = {Stein, Stefan and Pilgermann, Michael and Sedlmayr, Martin}, title = {Systematic Evaluation of Manufacturer Disclosure Statements for Medical Device Security (MDS2) to Strengthen Hospital OT Security Measures - Lessons Learned}, series = {Studies in health technology and informatics}, volume = {331}, journal = {Studies in health technology and informatics}, doi = {10.3233/SHTI251404}, pages = {256 -- 264}, year = {2025}, abstract = {The growing number of connected medical devices in hospitals poses serious operational technology (OT) security challenges. Effective countermeasures require a structured analysis of the communication interfaces and security configurations of individual devices. State of the art: Although Manufacturer Disclosure Statements for Medical Device Security (MDS2, Version 2019) offer relevant information, they are rarely integrated into cybersecurity workflows. Existing studies are limited in scope and lack scalable methodologies for systematic evaluation. Concept: This study analyzed 209 MDS2 documents and 161 security white papers to extract structured information on ports, protocols, and protective measures. Over 52,000 question-answer pairs were converted into a machine-readable format using customized parsing and validation routines. The aim was to establish whether this dataset could inform risk assessments and future applications involving Large Language Models (LLMs). Implementation: The analysis revealed 367 distinct ports, including common protocols such as HTTPS (443), DICOM (104), and RDP (3389), as well as vendor-specific proprietary ports. Approximately 40\% of the devices used over 20 ports, indicating a broad attack surface. OCR errors and inconsistent formatting required manual corrections. A consolidated dataset was developed to support clustering, comparison across vendors and versions, and preparation for downstream LLM use, particularly via structured SBOM and configuration data. Lessons learned: Although no model training was conducted, the structured dataset can support AI-based OT security workflows. The findings highlight the critical need for up-to-date, machine-readable manufacturer data in standardized formats and schemas. Such information could greatly enhance the automation, comparability, and scalability of hospital cybersecurity measures.}, language = {en} } @article{SteinPilgermannWeberetal.2025, author = {Stein, Stefan and Pilgermann, Michael and Weber, Simon and Sedlmayr, Martin}, title = {Leveraging MDS2 and SBOM data for LLM-assisted vulnerability analysis of medical devices}, series = {Computational and Structural Biotechnology Journal}, volume = {28}, journal = {Computational and Structural Biotechnology Journal}, publisher = {Elsevier}, doi = {10.1016/j.csbj.2025.07.012}, pages = {267 -- 280}, year = {2025}, abstract = {This study investigated the use of a semi-automated, Retrieval-Augmented Generation (RAG)-based multi-agent architecture to analyze security-relevant data and assemble specialized exploitation paths targeting medical devices. The input dataset comprised device-specific sources, namely, the Manufacturer Disclosure Statement for Medical Device Security (MDS2) documents and Software Bills of Materials (SBOMs), enriched with public vulnerability databases, including Common Vulnerabilities and Exposures (CVE), Known Exploited Vulnerabilities (KEV), and Metasploit exploit records. The objective was to assess whether a modular, Large Language Model (LLM)-driven agent system could autonomously correlate device metadata with known vulnerabilities and existing exploit information to support structured threat modeling. The architecture follows a static RAG design based on predefined prompts and fixed retrieval logic, without autonomous agent planning or dynamic query adaptation. The developed Vulnerability Intelligence for Threat Analysis in Medical Security (VITAMedSec) system operates under human-prompted supervision and successfully synthesizes actionable insights and exploitation paths without requiring manual step-by-step input during execution. Although technically coherent results were obtained under controlled conditions, real-world validation remains a critical avenue for future research. This study further discusses the dual-use implications of such an agent-based framework, its relevance to patient safety in medical device cybersecurity, and the broader applicability of the proposed architecture to other critical infrastructure sectors. These findings emphasize both the technical potential and ethical responsibility for applying semi-automated AI workflows in medical cybersecurity contexts.}, 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{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} } @article{TumarkinTyurninaMukhinetal.2022, author = {Tumarkin, Andrey and Tyurnina, Natalya and Mukhin, Nikolay and Tyurnina, Zoya and Sinelshchikova, Olga and Gagarin, Alexander and Sapego, Eugeny and Kretser, Yriy}, title = {Glass-ceramic ferroelectric composite material BaTiO3/KFeSi for microwave applications}, series = {Composite Structures}, volume = {281}, journal = {Composite Structures}, publisher = {Elsevier}, issn = {0263-8223}, pages = {1 -- 10}, year = {2022}, abstract = {Glass-ceramic composites consisting of potassium-iron-silicate glass and barium titanate mixed in various proportions were successfully synthesized by low-temperature sintering. The crystal structure of the obtained composite samples, the porosity and the microhardness were studied by the X-ray diffraction, the electron microscopy, the weight method, and the Vickers method. Electrical characteristics (dielectric permittivity, tunability and losses) of as-prepared and annealed in oxygen medium samples were investigated at microwaves. According to structural analysis, the synthesized samples are a mixture of KFeSi glass, ferroelectric BaTiO3, and dielectric barium polytitanates; the ratio of the latter determines the electrical properties of the composites. Depending on the content of barium titanate, the studied composite samples show a permittivity from 50 to 270 with a dielectric loss level of 0,1-0,02 in frequency range from 3 to 10 GHz. Annealing of composite samples in an oxygen-containing environment leads to an increase in their dielectric permittivity and tunability by 10-25\% and a twofold decrease in dielectric loss.}, language = {en} } @article{TumarkinTyurninaTyurninaetal.2020, author = {Tumarkin, Andrey and Tyurnina, Natalya and Tyurnina, Zoya and Mukhin, Nikolay and Sinelshchikova, Olga and Gagarin, Alexander and Sviridov, Sergey and Drozdovsky, Andrey and Sapego, Eugeny and Mylnikov, Ivan}, title = {Barium-Strontium Titanate/Porous Glass Structures for Microwave Applications}, series = {Materials}, volume = {13}, journal = {Materials}, number = {24}, publisher = {MDPI}, doi = {10.3390/ma13245639}, year = {2020}, language = {en} } @article{Uhl2023, author = {Uhl, Roland}, title = {Charakterisierung des Erwartungswertes am Graphen der Verteilungsfunktion}, publisher = {Technische Hochschule Brandenburg}, address = {Brandenburg an der Havel}, doi = {10.25933/opus4-2986}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:522-opus4-29862}, pages = {10}, year = {2023}, abstract = {Der Erwartungswert einer Zufallsgr{\"o}ße kann generell am Graphen ihrer Verteilungsfunktion durch eine naheliegende Gleichheit zweier Fl{\"a}cheninhalte festgelegt werden. {\"A}quivalent dazu l{\"a}sst er sich mit zwei uneigentlichen Riemann-Integralen darstellen. Davon ausgehend werden die Tschebyschow-Ungleichung und ihre Modifikation mit strikten Ungleichheitszeichen hergeleitet.}, subject = {Verteilungsfunktion}, language = {de} } @article{VaherTammSalusetal.2023, author = {Vaher, Ivi and Tamm, Anna-Liisa and Salus, Marit and Reisberg, Kirkke and V{\"a}hi, Aleksandra and Pallon, Helena and Paeste, Andra and Pirk, B{\"a}thel-Betty and Merila, Margus and Schrader, Thomas}, title = {Effectiveness of massage chair and classic massage in recovery from physical exertion: a pilot study}, series = {Journal of Novel Physiotherapy and Rehabilitation}, volume = {2023}, journal = {Journal of Novel Physiotherapy and Rehabilitation}, number = {7}, publisher = {HSPI}, doi = {10.29328/journal.jnpr.1001050}, pages = {8 -- 15}, year = {2023}, abstract = {Quick and cost-effective recovery is foundational to high-quality training and good competition results in today's sports. The aim of the research was to elucidate the effects of hand and massage chair massage on the biomechanical parameters of muscles of lower limbs and back, indicators of Pain Pressure Thresholds (PPT) and subjectively perceived fatigue. A total of 32 female recreational athletes (18 - 50 years old) were assigned to a hand massage, massage chair, or lying down the group. They were measured for muscle biomechanical properties (MyotonPro), PPT (Wagner Instruments) and subjectively perceived fatigue (VAS scale) before and after fatigue tests and treatment. The recovery procedure and subjective satisfaction with treatment were rated on a Likert scale. Changes in the median value of m. rectus femoris and m. gastrocnemius stiffness with treatment showed that hand massage could be more effective in reducing stiffness, as compared to chair massage. Hand massage may have benefits for recovery from physical exertion, but due to the individuality of subjects, detailed methodological studies are needed to evaluate the effects of massage chair vs. hand massage.}, 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{Vollmer2020, author = {Vollmer, Michael}, title = {Below the horizon-the physics of extreme visual ranges}, series = {Applied Optics}, volume = {59}, journal = {Applied Optics}, number = {21}, publisher = {Optica Publishing Group}, doi = {10.1364/AO.390654}, pages = {F11 -- F19}, year = {2020}, language = {en} } @article{Vollmer2021, author = {Vollmer, Michael}, title = {Gefrierende Gew{\"a}sser}, series = {Physik in unserer Zeit}, volume = {52}, journal = {Physik in unserer Zeit}, number = {1}, publisher = {Wiley-Blackwell}, doi = {10.1002/piuz.202001589}, pages = {19 -- 25}, year = {2021}, language = {de} } @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{Vollmer2025, author = {Vollmer, Michael}, title = {Nachtsicht ins All mit dem bloßen Auge: Sag mir, wie weit die Sterne steh'n}, series = {Physik in unserer Zeit}, volume = {2025}, journal = {Physik in unserer Zeit}, publisher = {Wiley}, doi = {10.1002/piuz.202501751}, pages = {2 -- 10}, year = {2025}, language = {de} } @article{Vollmer2025, author = {Vollmer, Michael}, title = {Naked eye celestial objects and phenomena: how far can we see at night?}, series = {European Journal of Physics}, volume = {46}, journal = {European Journal of Physics}, number = {3}, publisher = {IOP Science}, doi = {10.1088/1361-6404/adbf74}, pages = {18}, year = {2025}, abstract = {How far can we see with the naked eye at night? Many celestial objects like stars and galaxies as well as transient phenomena such as comets and supernovae can be observed in the night sky. We discuss the furthest distances of such objects and phenomena observable with the naked eye during the night-time for Earth-bound observers. The physics of night-time visual ranges differs from that of daytime observations because human vision shifts from cones to rods. In addition, mostly point sources are observed due to the large distances involved. Whether celestial objects and phenomena can be detected depends on the contrast of their radiation and the background sky luminance. We present a concise overview of how far we can see at night by first discussing the effects of the Earth's atmosphere. This includes attenuation of transmitted radiation as well as its role as a source of background radiation. Disregarding the attenuation of light due to interstellar and intergalactic dust, simple maximum night-time visual range estimates are based on the inverse square law, which can be easily verified by laboratory and demonstration experiments. From the respective calculations, we find that individual stars within the Milky Way galaxy of up to 15 000 light years are observable. Even further away are observable galaxies with several billion stars. The Andromeda galaxy can be observed with the naked eye at a distance of around 2.5 million light years. Similarly, the observability of supernovae also allows a visual range beyond the Milky Way galaxy. Finally, gamma ray bursts as the most energetic events in the universe are discussed concerning naked eye observations.}, language = {en} } @article{Vollmer2025, author = {Vollmer, Michael}, title = {How far can we see at day?}, series = {European Journal of Physics}, volume = {46}, journal = {European Journal of Physics}, number = {3}, publisher = {IOP Science}, doi = {10.1088/1361-6404/adc4a0}, pages = {17}, year = {2025}, abstract = {We discuss the farthest objects on Earth observable for the unaided, healthy naked eye during the daytime, i.e., the maximum visual range for observers on Earth. Visual range depends first on the properties of the material between observer and object and its interaction processes with radiation, but second also on our visual perception system. After a rough comparison of ranges in water, glass, and the atmosphere, we focus on the physical basis of visual range for the latter. As a contrast phenomenon, visual range refers to allowed light paths within the atmosphere. It results from the interplay of geometry, refraction, and light scattering. We present a concise overview of this field by qualitative descriptions and quantitative estimates as well as classroom demonstration experiments. The starting point is the common geometrical visual ranges, followed by extensions due to refraction and limitations due to contrast, which depend on scattering and absorption processes within the atmosphere. The quantitative discussion of scattering is very helpful to easily understand the huge ranges in nature from meters in dense fog to hundreds of kilometers in clear atmospheres. Extreme visual ranges from about 300 km to above 500 km require optimal atmospheric conditions, cleverly chosen locations and times, and a sophisticated topography analysis. Even longer visual ranges are possible when looking through the vertical atmosphere. From the ISS, daytime ranges well above 1000 km are possible.}, language = {en} } @article{Vollmer2026, author = {Vollmer, Michael}, title = {How many stars appear colored to the naked eye?}, series = {Applied Optics}, volume = {65}, journal = {Applied Optics}, number = {9}, publisher = {Optica Publishing Group}, doi = {10.1364/AO.580635}, pages = {C27 -- C37}, year = {2026}, abstract = {Naked eye studies of the clear night sky reveal that a certain percentage of all observable stars can be perceived as having color. Subjective estimates differ widely, ranging from just a few to a maximum of above two hundred. Explanations are based on the emission spectra of the stars, which are modified by interstellar dust clouds, the Earth atmosphere, and mostly the inverse square law. Color changes occur not only for variation of the star's angular elevation above the horizon, but as well for decreasing nighttime sky brightness due to the transition from photopic via mesopic to scotopic vision. The maximum number of stars showing color to the naked eye depends on star illuminances on Earth and the background sky luminance. The limit of observing color is found to correspond to apparent visual magnitudes around , defining the number of colored stars. This also means that naked eye perception of stars with color is only possible for a certain star distance range, which is well below the maximum naked eye visual range of stars.}, 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{VollmerMoellmann2020, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Unsichtbares sichtbar gemacht: Infrarotkameras f{\"u}r Smartphones}, series = {Physik in unserer Zeit}, volume = {51}, journal = {Physik in unserer Zeit}, number = {1}, publisher = {Wiley-VCH}, doi = {https://doi.org/10.1002/piuz.201901551}, pages = {29 -- 35}, year = {2020}, language = {de} } @article{VollmerMoellmann2020, author = {Vollmer, Michael and M{\"o}llmann, Klaus-Peter}, title = {Wenn Licht die Biege macht}, series = {Physik in unserer Zeit}, volume = {51}, journal = {Physik in unserer Zeit}, number = {1}, publisher = {Wiley-VCH}, doi = {https://doi.org/10.1002/piuz.202001569}, pages = {46 -- 47}, year = {2020}, language = {de} } @article{WangHarthPuzyrevetal.2022, author = {Wang, Jing and Harth, Kirsten and Puzyrev, Dmitry and Stannarius, Ralf}, title = {The effect of obstacles near a silo outlet on the discharge of soft spheres}, series = {New Journal of Physics}, volume = {24}, journal = {New Journal of Physics}, publisher = {IOP}, doi = {10.1088/1367-2630/ac8bea}, 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{WehlandCorydonGonzalezTorresetal.2025, author = {Wehland, Markus and Corydon, Thomas J. and Gonz{\´a}lez-Torres, Luis Fernando and Abdelfattah, Fatima and Sahana, Jayashree and Schulz, Herbert and Mushunuri, Ashwini and Burenkova, Hanna and Wuest, Simon L. and Kr{\"u}ger, Marcus and Kraus, Armin and Grimm, Daniela}, title = {New Knowledge About Tissue Engineering Under Microgravity Conditions in Space and on Earth}, series = {International Journal of Molecular Sciences}, volume = {27}, journal = {International Journal of Molecular Sciences}, number = {1}, publisher = {MDPI}, doi = {10.3390/ijms27010341}, year = {2025}, abstract = {Microgravity (µg)-generated three-dimensional (3D) multicellular aggregates can serve as models of tissue and disease development. They are relevant in the fields of cancer and in vitro metastasis or regenerative medicine (tissue engineering). Driven by the 3R concept—replacement, reduction, and refinement of animal testing—µg-exposure of human cells represents a new alternative method that avoids animal experiments entirely. New Approach Methodologies (NAMs) are used in biomedical research, pharmacology, toxicology, cancer research, radiotherapy, and translational regenerative medicine. Various types of human cells grow as 3D spheroids or organoids when exposed to µg-conditions provided by µg simulating instruments on Earth. Examples for such µg-simulators are the Rotating Wall Vessel, the Random Positioning Machine, and the 2D or 3D clinostat. This review summarizes the most recent literature focusing on µg-engineered tissues. We are discussing all reports examining different tumor cell types from breast, lung, thyroid, prostate, and gastrointestinal cancers. Moreover, we are focusing on µg-generated spheroids and organoids derived from healthy cells like chondrocytes, stem cells, bone cells, endothelial cells, and cardiovascular cells. The obtained data from NAMs and µg-experiments clearly imply that they can support translational medicine on Earth.}, language = {en} } @article{WeimerBuschhartBroelzetal.2022, author = {Weimer, Katja and Buschhart, Cliff and Broelz, Ellen K. and Enck, Paul and Horing, Bj{\"o}rn}, title = {Bibliometric Properties of Placebo Literature From the JIPS Database: A Descriptive Study}, series = {Frontiers in Psychiatry}, volume = {13}, journal = {Frontiers in Psychiatry}, publisher = {Frontiers Research Foundation}, issn = {1664-0640}, doi = {10.3389/fpsyt.2022.853953}, year = {2022}, language = {en} } @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{WidjajaLoeweCosta2018, author = {Widjaja, Agnes S. N. and L{\"o}we, Katharina and Costa, Felipe Salerno}, title = {Design and simulation of a concentrated solar thermal system with an integrated concrete storage for continuous heat supply}, series = {Energy Procedia}, volume = {155}, journal = {Energy Procedia}, doi = {10.1016/j.egypro.2018.11.062}, pages = {121 -- 135}, year = {2018}, language = {en} } @article{YuekselSchwarzCreutzburg2020, author = {Y{\"u}ksel, Benjamin and Schwarz, Klaus and Creutzburg, Reiner}, title = {AI-based anomaly detection for cyberattacks on Windows systems-Creation of a prototype for automated monitoring of the process environment}, 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-331}, pages = {331-1 -- 331-13}, year = {2020}, language = {en} }