@article{FibichSchmittHoelleretal., author = {Fibich, Christian and Schmitt, Patrick and H{\"o}ller, Roland and R{\"o}ssler, Peter}, title = {Open-Source Ethernet MAC IP Cores for FPGAs: Overview and Evaluation}, series = {International Journal of Reconfigurable Computing}, volume = {2023}, journal = {International Journal of Reconfigurable Computing}, doi = {https://doi.org/10.1155/2023/9222318}, pages = {Article ID 9222318}, subject = {Ethernet}, language = {en} } @article{Himmelstoss, author = {Himmelstoss, Felix}, title = {Design of State-Space Controllers with the Help of Signal Flow Graphs Shown for a Buck Converter}, series = {WSEAS Transactions on Power Systems, Volume 21, 2022, pp. 421-429}, volume = {Volume 21}, journal = {WSEAS Transactions on Power Systems, Volume 21, 2022, pp. 421-429}, doi = {10.37394/23202.2022.21.46}, pages = {421 -- 429}, subject = {DC/DC converter}, language = {en} } @article{HimmelstossVotzi, author = {Himmelstoss, Felix and Votzi, Helmut}, title = {Simple Chargers for a Small DC Micro-Grid for a Home Emergency Power System}, series = {Electricity}, volume = {4}, journal = {Electricity}, number = {3}, doi = {https://doi.org/10.3390/electricity4030013}, pages = {216 -- 234}, subject = {micro-grid}, language = {en} } @article{Himmelstoss, author = {Himmelstoss, Felix}, title = {Quasi Resonant Zero Current Switching Modified Boost Converter (QRZCSMBC)}, series = {WSEAS Transactions on Power Systems}, volume = {Volume 22}, journal = {WSEAS Transactions on Power Systems}, doi = {10.37394/23201.2023.22.8}, pages = {55 -- 62}, subject = {DC/DC converter}, language = {en} } @article{Himmelstoss, author = {Himmelstoss, Felix}, title = {Third order converters with current output for driving LEDs}, series = {WSEAS Transactions on Power Systems}, volume = {Volume 17}, journal = {WSEAS Transactions on Power Systems}, doi = {10.37394/232016.2022.17.40}, pages = {402 -- 409}, subject = {DC/DC converters}, language = {en} } @article{MarcKnappNateqietal., author = {Marc, Zobel and Knapp, Bernhard and Nateqi, Jama and Martin, Alistair}, title = {Correlating global trends in COVID-19 cases with online symptom checker self-assessments}, series = {PLOS ONE}, volume = {18}, journal = {PLOS ONE}, number = {2}, doi = {https://doi.org/10.1371/journal.pone.0281709}, pages = {10}, abstract = {Background Online symptom checkers are digital health solutions that provide a differential diagnosis based on a user's symptoms. During the coronavirus disease 2019 (COVID-19) pandemic, symptom checkers have become increasingly important due to physical distance constraints and reduced access to in-person medical consultations. Furthermore, various symptom checkers specialised in the assessment of COVID-19 infection have been produced. Objectives Assess the correlation between COVID-19 risk assessments from an online symptom checker and current trends in COVID-19 infections. Analyse whether those correlations are reflective of various country-wise quality of life measures. Lastly, determine whether the trends found in symptom checker assessments predict or lag relative to those of the COVID-19 infections. Materials and methods In this study, we compile the outcomes of COVID-19 risk assessments provided by the symptom checker Symptoma (www.symptoma.com) in 18 countries with suitably large user bases. We analyse this dataset's spatial and temporal features compared to the number of newly confirmed COVID-19 cases published by the respective countries. Results We find an average correlation of 0.342 between the number of Symptoma users assessed to have a high risk of a COVID-19 infection and the official COVID-19 infection numbers. Further, we show a significant relationship between that correlation and the self-reported health of a country. Lastly, we find that the symptom checker is, on average, ahead (median +3 days) of the official infection numbers for most countries. Conclusion We show that online symptom checkers can capture the national-level trends in coronavirus infections. As such, they provide a valuable and unique information source in policymaking against pandemics, unrestricted by conventional resources.}, subject = {Online symptom checkers}, language = {en} } @inproceedings{HimmelstossWindisch, author = {Himmelstoss, Felix and Windisch, Michael}, title = {A capacitor-free driving stage for light emitting diodes}, series = {21th International Conference on Renewable Energies and Power Quality (ICREPQ'23) Madrid (Spain), 24th to 26th May 2023}, volume = {Vol. 21}, booktitle = {21th International Conference on Renewable Energies and Power Quality (ICREPQ'23) Madrid (Spain), 24th to 26th May 2023}, doi = {10.24084/repqj21.278}, pages = {220 -- 225}, abstract = {Electrolytic capacitors have the disadvantage of pronounced aging. Non-electrolytic capacitors are therefore used in applications where long-life is important. In this paper we present a driving stage for LEDs without any capacitive elements. The basic topology is a Buck converter with one coil, one active, and one passive switch. Instead of the output capacitor, series connections of one or more LEDs and an active switch are connected. An additional diode is connected between the output and the input to achieve a current path, when all LED- paths are off. A nonlinear hysteresis controller is used to achieve a robust control. A system with three switchable LED-strings is analyzed. Design hints are given and the function is proved with the help of LTSpice simulations. The system can be used for lighting purposes with the possibility to change the chrominance. The potentiality to transmit data is also treated.}, subject = {DC-to-DC converter}, language = {en} } @inproceedings{HimmelstossWindisch, author = {Himmelstoss, Felix and Windisch, Michael}, title = {Tapped inductor Boost with exploitation of the stray energy}, series = {Proceedings of 2022 IEEE 20th International Power Electronics and Motion Control Conference (PEMC 2022), Brasov, Rumania, Sep. 25-29}, booktitle = {Proceedings of 2022 IEEE 20th International Power Electronics and Motion Control Conference (PEMC 2022), Brasov, Rumania, Sep. 25-29}, doi = {10.1109/PEMC51159.2022.9962849}, pages = {75 -- 80}, abstract = {Tapped inductor DC-to-DC converters are interesting circuits, the winding ratio of the two windings mounted on the same core change the voltage transformation ratio compared to the untapped inductor. The tapped inductor converters are especially useful, when high or low voltage transformation ratios have to be realized. The disadvantage of this concept is that the coupling between the two windings is not total and can be described by the stray or leakage inductance. This stray inductance leads to a high overvoltage at the active switch, and therefore also across other elements of the converter. After a short summery of the ideal tapped Boost converter, the design of an RCD snubber which limits the overvoltage is explained. To improve the efficiency of the converter two active snubber networks are treated, which feed the energy stored in the snubber capacitor into the input source or into the output circuit. Simulations are used to prove these considerations.}, subject = {DC/DC converter}, language = {en} } @inproceedings{HimmelstossVotzi, author = {Himmelstoss, Felix and Votzi, Helmut}, title = {Two-Stage Step-up Converter with Different Voltage Transformation Ratios depending on the Duty Cycle}, series = {20th International Conference on Renewable Energies and Power Quality (ICREPQ'22) Vigo (Spain), 27th to 29th July 2022}, volume = {Vol. 20}, booktitle = {20th International Conference on Renewable Energies and Power Quality (ICREPQ'22) Vigo (Spain), 27th to 29th July 2022}, doi = {10.24084/repqj20.218}, pages = {66}, abstract = {A two-stage converter with high output voltage ratio and reduced current stress of the inductors and partly reduced voltage stress is discussed. The function is explained with the help of voltage and current diagrams. The voltage transformation ratio changes between a quadratic step-up for duty cycles lower 0.5 and a double Boost converter for duty cycles higher than 0.5. Dimensioning hints, the control law for feed-forward controls, the transient when the supply is turned on is discussed and some simulations are given. A comparison to other two-stage converters is also treated.}, subject = {Quadratic boost}, language = {en} } @inproceedings{FibichHorauerObermaisser, author = {Fibich, Christian and Horauer, Martin and Obermaisser, Roman}, title = {Bitstream-Level Interconnect Fault Characterization for SRAM-based FPGAs}, series = {Proceedings of the 2023 Design, Automation \& Test in Europe Conference \& Exhibition (DATE 2023), pp. 1-2, 16-18 April 2023, Antwerp, Belgium}, booktitle = {Proceedings of the 2023 Design, Automation \& Test in Europe Conference \& Exhibition (DATE 2023), pp. 1-2, 16-18 April 2023, Antwerp, Belgium}, doi = {10.23919/DATE56975.2023.10136911}, pages = {2}, subject = {FPGA}, language = {en} } @article{WalaFelleitnerGollWechselberger, author = {Wala, Thomas and Felleitner-Goll, Katharina and Wechselberger, Harald}, title = {Stellhebel beim Aufbau von Corporate Start-ups. Dargestellt am Start-Up-Projekt „Hallo Sonne"}, series = {CFO aktuell}, journal = {CFO aktuell}, number = {7}, pages = {130 -- 134}, subject = {Start-ups}, language = {de} } @article{WalaFelleitnerGoll, author = {Wala, Thomas and Felleitner-Goll, Katharina}, title = {Digitalisierung in der Weiterbildung. Wie man mit eigenen Online-Kursen ein passives Zusatzeinkommen generieren kann.}, series = {ASoK}, journal = {ASoK}, number = {5}, pages = {189 -- 191}, subject = {Weiterbildung}, language = {de} } @article{WalaFelleitnerGoll, author = {Wala, Thomas and Felleitner-Goll, Katharina}, title = {Technologiemanagement}, series = {WISU}, journal = {WISU}, number = {4}, pages = {349 -- 350}, subject = {Technologiemanagement}, language = {de} } @article{KierspelKadekBarranetal., author = {Kierspel, Thomas and Kadek, Alan and Barran, Perdita and Bellina, Bruno and Bijedic, Adi and Brodmerkel, Maxim N. and Commandeur, Jan and Caleman, Carl and Damjanovic, Tomislav and Dawod, Ibrahim and De Santis, Emiliano and Lekkas, Alexandros and Lorenzen, Kristina and L{\´o}pez Morillo, Luis and Mandl, Thomas and Marklund, Erik G. and Papanastasiou, Dimitris and Ramakers, Lennart A. I. and Schweikhard, Lutz and Simke, Florian and Sinelnikova, Anna and Smyrnakis, Athanasios and Timneanu, Nicusor and Uetrecht, Charlotte}, title = {Coherent diffractive imaging of proteins and viral capsids: simulating MS SPIDOC}, series = {Analytical and Bioanalytical Chemistry}, volume = {2023}, journal = {Analytical and Bioanalytical Chemistry}, number = {415}, doi = {https://doi.org/10.1007/s00216-023-04658-y}, pages = {4209 -- 4220}, abstract = {MS SPIDOC is a novel sample delivery system designed for single (isolated) particle imaging at X-ray Free-Electron Lasers that is adaptable towards most large-scale facility beamlines. Biological samples can range from small proteins to MDa particles. Following nano-electrospray ionization, ionic samples can be m/z-filtered and structurally separated before being oriented at the interaction zone. Here, we present the simulation package developed alongside this prototype. The first part describes how the front-to-end ion trajectory simulations have been conducted. Highlighted is a quadrant lens; a simple but efficient device that steers the ion beam within the vicinity of the strong DC orientation field in the interaction zone to ensure spatial overlap with the X-rays. The second part focuses on protein orientation and discusses its potential with respect to diffractive imaging methods. Last, coherent diffractive imaging of prototypical T = 1 and T = 3 norovirus capsids is shown. We use realistic experimental parameters from the SPB/SFX instrument at the European XFEL to demonstrate that low- resolution diffractive imaging data (q < 0.3 nm -1 ) can be collected with only a few X-ray pulses. Such low-resolution data are sufficient to distinguish between both symmetries of the capsids, allowing to probe low abundant species in a beam if MS SPIDOC is used as sample delivery.}, subject = {SPI}, language = {en} } @inproceedings{SteinerLuegerWallischetal., author = {Steiner, Fabian and Lueger, Bernhard and Wallisch, Bernhard and Polzer, Thomas}, title = {Automated Evaluation System for Microcontroller Assignments}, series = {2023 IEEE Global Engineering Education Conference (EDUCON), Kuwait}, booktitle = {2023 IEEE Global Engineering Education Conference (EDUCON), Kuwait}, organization = {IEEE}, isbn = {979-8-3503-9943-1}, issn = {2165-9567}, doi = {https://doi.org/10.1109/EDUCON54358.2023.10125112}, pages = {7}, abstract = {As IoT systems have increased the number of deployed embedded devices drastically and most of these devices are used in safety or security critical environments, the education of embedded software engineers is more important than ever. A critical part of their education is the development of their intuition for secure and safe software. In this paper 1 1 This research was funded by the city of Vienna (MA-23 call 21, project no. 9). we present an evaluation system used to generate fast and accurate feedback for student submission in, but not limited to, embedded software development courses. The system can be used as a first feedback loop to outline to the students where problems exist in their code and give them the opportunity to analyze and correct their errors. These extra steps ensure that the students can and will be notified early about their mistakes and can search for correct solutions, supporting the student's learning process. We present the implementation of the system and analyze its deployment in a microcontroller software development lecture. This analysis was done by means of surveys of the students and lecturers as well as a statistical analysis of the student submissions. The results show that the students made use of this extra features and even would prefer to have this feedback in other software development lectures as well.}, subject = {Student-Centered Learning Environments}, language = {en} } @inproceedings{HimmelstossHofschweigerVotzi, author = {Himmelstoss, Felix and Hofschweiger, Andreas and Votzi, Helmut}, title = {Quadratic Combined Forward-Flyback Converter}, series = {Power Conversion and Intelligent Motion Conference (PCIM) 2023, May 9-11, 2023 Nurenberg, Germany}, booktitle = {Power Conversion and Intelligent Motion Conference (PCIM) 2023, May 9-11, 2023 Nurenberg, Germany}, doi = {10.30420/566091315}, pages = {1446 -- 1453}, subject = {DC/DC converter}, language = {en} } @inproceedings{HimmelstossErtlVotzi, author = {Himmelstoss, Felix and Ertl, Benjamin and Votzi, Helmut}, title = {A new limited duty cycle step-up converter}, series = {International European Conference on Interdisciplinary Scientific Research, July 13-15, 2023, Rome, Italy}, booktitle = {International European Conference on Interdisciplinary Scientific Research, July 13-15, 2023, Rome, Italy}, pages = {811 -- 833}, subject = {DC/DC converter}, language = {en} } @inproceedings{HimmelstossEdelmoser, author = {Himmelstoss, Felix and Edelmoser, Karl}, title = {Liquid and surface disinfection with pulsed UVC LEDs}, series = {2nd Ahi Evran International Conference on Scientific Research, Kirshehir, Turkey, October 21-23, 2022}, booktitle = {2nd Ahi Evran International Conference on Scientific Research, Kirshehir, Turkey, October 21-23, 2022}, pages = {654 -- 664}, subject = {disinfection}, language = {en} } @inproceedings{HimmelstossYamanEdelmoser, author = {Himmelstoss, Felix and Yaman, Ferhat and Edelmoser, Karl}, title = {Building block for a spot welder}, series = {International Congress on Innovation Technologies \& Engineering, Sept. 2-4, 2022, Izmir, Turkey, pp. 139-148}, booktitle = {International Congress on Innovation Technologies \& Engineering, Sept. 2-4, 2022, Izmir, Turkey, pp. 139-148}, pages = {139 -- 148}, subject = {spot welding}, language = {en} } @inproceedings{Himmelstoss, author = {Himmelstoss, Felix}, title = {Concept to change the voltage transformation ratio of a DC/DC converter}, series = {Cukurova 9th International Scientific Researches Conference, Oct. 9-11, 2022, Adana, Turkey, pp. 258-273}, booktitle = {Cukurova 9th International Scientific Researches Conference, Oct. 9-11, 2022, Adana, Turkey, pp. 258-273}, pages = {258 -- 273}, subject = {DC/DC converter}, language = {en} }