TY - CHAP A1 - Roth, Carina A1 - Hausler, Peter A1 - Bierl, Rudolf T1 - Einbindung eines CMOS-Detektors in einen hochintegrierten SPR-Sensor T2 - 5. Landshuter Symposium Mikrosystemtechnik, März 2016 Y1 - 2016 SN - 78-3-9812696-9-7 SP - 200 EP - 205 PB - Fachhochschule Landshut CY - Landshut ER - TY - CHAP A1 - Lang, Christian A1 - Steinborn, Florian A1 - Steffens, Oliver A1 - Lang, Elmar Wolfgang ED - Valenzuela, O. ED - Rojas, F. ED - Herrera, L.J. ED - Pomares, H. ED - Rojas, I. T1 - Applying a 1D-CNN Network to Electricity Load Forecasting T2 - Theory and Applications of Time Series Analysis N2 - This paper presents a convolutional neural network (CNN) which can be used for forecasting electricity load profiles 36 hours into the future. In contrast to well established CNN architectures, the input data is one-dimensional. A parameter scanning of network parameters is conducted in order to gain information about the influence of the kernel size, number of filters and number of nodes. Furthermore, different dropout methods are applied to the CNN and are evaluated. The results show that a good forecast quality can already be achieved with basic CNN architectures, the dropout improves the forecast. The method works not only for smooth sum loads of many hundred consumers, but also for the load of single apartment buildings. KW - Energy load forecasting KW - STLF KW - Neural networks KW - CNN KW - Convolutional networks Y1 - 2020 U6 - https://doi.org/10.1007/978-3-030-56219-9_14 SP - 205 EP - 218 PB - Springer ER - TY - JOUR A1 - Reuther, Maike A1 - Steffens, Oliver T1 - Evaluation der Bauteiltemperierung für den Herzogskasten Abensberg JF - Bauphysik N2 - Die These, dass die Methode der direkten Temperierung von erdberührten oder anderweitig feuchtebelasteten Bauteilen zur Beseitigung von Feuchteschäden in Bestandsgebäuden auch die Energieeffizienz des Gebäudes erhöhen und sogar ohne weitere energetische Sanierungsmaßnahmen die Anforderungen der Energieeinsparverordnung (EnEV) erfüllen kann, wird anhand des als Museum genutzten Herzogskastens in Abensberg überprüft. In Verbindung mit einer Evaluation der Trocknungswirkung wird die Gebäude-Energieeffizienz durch Vergleich von Bedarfsberechnungen auf Basis der DIN V 18599 mit realen Verbrauchszahlen überprüft und diskutiert. KW - Bauteiltemperierung KW - energetische Sanierung KW - Gebäudeenergieeffizienz KW - Mauerwerkstrocknung KW - Denkmal KW - Restaurierung KW - DIN V 18599 KW - EnEV Y1 - 2015 U6 - https://doi.org/10.1002/bapi.201510010 VL - 37 IS - 2 SP - 96 EP - 99 PB - Ernst & Sohn, a Wiley Brand ER - TY - RPRT A1 - Schlamp, Matthias A1 - Ehrlich, Ingo ED - Baier, Wolfgang T1 - Analyse des Impact-Verhaltens gekrümmter Strukturbauteile von Luftfahrzeugen zur Entwicklung eines Strukturüberwachungssystems für faserverstärkte Kunststoffe - BIRD T2 - Forschung 2019 / Ostbayerische Technische Hochschule Regensburg N2 - Die in Flugvorausrichtung weisenden Bauteile von Luftfahrzeugen sind oftmals durch Einschläge aufgrund von Vogelschlag, Hagel oder aufgewirbelten Kleinteilen gefährdet. Diese Einschläge, sogenannte Impacts, weisen bei faserverstärkten Kunststoffen ein stark krümmungs- und materialabhängiges Verhalten und Schadensausmaß auf. Impact-Schädigungen führen oftmals zu hohen Reparaturkosten, welche durch eine genauere Kenntnis des Schadens verringert werden können. Zur Klassifizierung dieser Schädigungen steht dabei vor allem das auftretende Frequenz signal des Impacts im Fokus der Untersuchungen. Y1 - 2019 UR - https://doi.org/10.35096/othr/pub-789 SN - 978-3-9818209-6-6 SP - 40 EP - 41 PB - VMK Verlag für Marketing & Kommunikation GmbH & Co. KG ER - TY - JOUR A1 - Romano, Marco A1 - Micklitz, Matthias A1 - Olbrich, Florian A1 - Bierl, Rudolf A1 - Ehrlich, Ingo A1 - Gebbeken, Norbert T1 - Experimental investigation of damping properties of unidirectionally and fabric reinforced plastics by the free decay method JF - Journal of Achievements in Materials and Manufacturing Engineering N2 - Purpose: of this paper is experimental investigation of damping properties of unidirectionally and fabric reinforced plastics by the free decay method. Design/methodology/approach: For the evaluation of the presumed effect experimental structural dynamic investigations comparing unidirectionally and fabric reinforced plastics are carried out. In detail the free decay behaviour of flat beamlike specimens under fixed-free boundary conditions and relatively constant and reproducible displacement excitation is investigated. Findings: The vibrating structure has been measured by a laser scanning vibrometer PSV 400 from POLYTEC. In both cases evaluation of the results yields enhanced damping properties of the specimens with fabric reinforcement compared to the unidirectionally reinforced specimens. The results justify the presumed acting of a mesomechanic kinematic. Research limitations/implications: The results show that in either case the material damping in terms of the logarithmic decrement of the fabric reinforced material is higher than the material damping in of the unidirectionally reinforced material. Additionally, when the fabric reinforced specimens are addressed, in each case the plain weave reinforced specimens exhibited higher values of the material damping as the twill weave 2/2 reinforced ones. Originality/value: Ondulations in fabrics as a textile semi-finished product are caused by the alternating crossing of warp and fill yarns. In the mesoscopic scale the acting of a mesomechanic kinematic is presumed to enhance the damping properties under cyclic elastic deformation. For the evaluation of the presumed effect experimental structural dynamic investigations comparing unidirectionally and fabric reinforced plastics are carried out. KW - structural vibration KW - damping KW - fibre reinforced plastics KW - mesomechanic scale KW - fabric reinforced layer Y1 - 2014 VL - 63 IS - 2 SP - 65 EP - 80 ER - TY - CHAP A1 - Jobst, Simon A1 - Bierl, Rudolf T1 - A Comparison of Correlation and Zero-Crossing Based Techniques in Ultrasonic Measurement T2 - 10th International Symposium on Applied Reconfigurable Computing (ARC'2014), Vilamoura, Algarve, Portugal, 14 - 16 April, 2014 N2 - Ultrasound measurement technology has advancedin previous decades due to positive developments in computing power and lower cost for the necessary hardware. Correlation-based processing can be advantageous for high-accuracy measurements, especially in noisy environments. Higher computational load makes correlation less attractive for industrialapplications, though, favouring traditional processing techniques. A platform for comparing various processing techniques hasbeen developed. It was found that both zero-crossing detectionas well as correlation can achieve very high accuracy over a hightemperature range but that correlation-based processing can lead to a significant precision bias depending on system bandwidth. Y1 - 2014 ER - TY - CHAP A1 - Hofmann, Matthias A1 - Bierl, Rudolf A1 - Rück, Thomas T1 - Implementation of a dual-phase lock-in amplifier on a TMS320C5515 digital signal processor T2 - Proceedings of the 5th European DSP Education and Research Conference (EDERC), 13-14 Sept. 2012, Amsterdam N2 - A digital dual-phase lock-in amplifier that is capable to run on a low-cost, low-power platform comprising a 16-bit fixed-point digital signal processor was developed. This is achieved by a set of optimised digital filters including an exponential averager to adjust the time constant of the overall filter. The reference frequency is generated using a direct digital synthesis source utilising angle decomposition with a resolution of 1 Hz. The digital lock-in algorithm is described and the performance of the algorithm is analysed. The experimental results show that the developed lock-in amplifier achieves similar performance to a commercially available lock-in amplifier. Y1 - 2012 U6 - https://doi.org/10.1109/EDERC.2012.6532217 ER - TY - CHAP A1 - Rück, Thomas A1 - Landgraf, Ferdinand A1 - Läpple, I. A1 - Unger, J. A1 - Matysik, Frank-Michael A1 - Bierl, Rudolf T1 - Specification of an improved photoacoustic setup for high-sensitive, low-cost NO2 trace gas detection T2 - 18th International Conference on Photoacoustic and Photothermal Phenomena (ICPPP18), 2015, September 6-10, Novi Sad, Serbia Y1 - 2015 ER - TY - CHAP A1 - van der Weerd, Bastiaan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - A Conductivity Probe for the Determination of Carbon Dioxide Tension at the Oxygenator Exhaust Outlet during Extracorporeal Membrane Oxygenation (ECMO) T2 - analytica Conference 2014, 1. bis 4. April, München Y1 - 2014 ER - TY - CHAP A1 - van der Weerd, Bastiaan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - A Conductivity Probe for the Determination of Carbon Dioxide Tension at the Oxygenator Exhaust Outlet during Extracorporeal Membrane Oxygenation (ECMO) T2 - Electrochemistry 2014, September 22 - 24, Mainz Y1 - 2014 ER - TY - CHAP A1 - van der Weerd, Bastiaan A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - A Planar Conductivity Probe for CO2 Determination at the Oxygenator Outlet T2 - Doktorandenseminar GDCh Prozessanalytik 2014, Berlin Y1 - 2014 ER - TY - CHAP A1 - Theuss, Horst A1 - Elian, Klaus A1 - Fink, Markus A1 - Fries, M. A1 - Kalz, Franz-Peter A1 - Schwabe, B. A1 - Vaupel, M. A1 - Jaroschek, C. A1 - Schubert, A. A1 - Hummel, H. A1 - Steffens, Oliver T1 - Mechanical Stress Impact of Assembly Processes onto a Stress-sensitive Testchip T2 - 44th International Symposium on Microelectronics (IMAPS 2011), October 9 - 13, 2011, Long Beach, California, USA N2 - A semiconductor die typically undergoes a variety of assembly processes, each of them influencing the mechanical stress environment of the chip. We report on a stress-sensitive testchip and its application to measure and characterize the respective stress distributions across the die. Particularly in the field of MEMS and sensor devices, even low stresses might deteriorate the electrical performance of a device significantly, while higher stress levels may even cause cracks and irreversible damage. This is why the present methodology has a high potential to develop into a useful tool in the field of sensor package development. After a brief introduction to the sensing principle, we investigate the stress distribution in various sample assemblies – all of them targeting pressure sensors. Typical low stress packages use silicone based soft elastic encapsulations. Changing to a harder material with a young’s modulus comparable to standard mold compounds, we demonstrate an increase of the average stress level by more than one order of magnitude. Y1 - 2011 SN - 978-1-61839-850-5 U6 - https://doi.org/10.4071/isom-2011-WA5-Paper3 IS - 1 SP - 619 EP - 626 PB - International Microelectronics & Packaging CY - Washington ER - TY - JOUR A1 - Malz, Sebastian A1 - Steininger, Peter A1 - Dawoud, Belal A1 - Krenkel, Walter A1 - Steffens, Oliver T1 - On the Development of a Building Insulation using Air Layers with Highly Reflective Interfaces JF - Energy and Buildings N2 - In this work, a novel building insulation system implying wooden fiberboards and intermediate air layers with highly reflective interfaces for the reflection of longwave IR radiation is introduced. A wall test sample with a double air insulation layer has been built and experimentally investigated in a dedicated setup, which consists of a differential climatic chamber to simulate different indoor and outdoor conditions. The test results have been utilized in validating the developed simulation model. In addition, a thorough numerical parameter study has been conducted, through which the general design rules of the introduced insulation system for realizing the lowest possible effective thermal conductivity have been defined. Furthermore, a multi-air-layer-insulation concept is developed, and the energy saving potential is evaluated. It turned out that, emissivity, object size and air layer thickness are the most dominant design parameters which influence the thermal conductivity of the introduced insulation. A thermal conductivity of 0.033 W/(mK) has been estimated for a multi-air-layer insulation with 7 layers. The obtained results prove the high insulation potential of the introduced building insulation system compared with insulating materials available in the market while outlining their limitations. KW - Building insulation KW - Infrared-reflective KW - Air layers KW - Energy-saving potential KW - Heat radiation Y1 - 2021 U6 - https://doi.org/10.1016/j.enbuild.2021.110779 IS - 236, April PB - Elsevier ER - TY - CHAP A1 - Steffens, Oliver A1 - Szabó, Peter A1 - Lenz, Michael A1 - Farkas, Gábor T1 - Thermal transient characterization methodology for single-chip and stacked structures BT - Best Paper Award T2 - Semiconductor Thermal Measurement and Management Symposium, 2005 N2 - High-power semiconductor packages typically exhibit a 3D heat flow, resulting in large lateral changes in chip and case surface temperature. For single-chip devices we propose to use an unambiguous definition for the junction-to-case thermal resistance as a key parameter, based on a transient measurement technique with much higher repeatability, also for very low thermal resistances compared to a two-point thermal resistance measurement. The technique is illustrated on thermal transient measurements of power MOSFETs. A comparison between different thermal coupling to the ambient is used to demonstrate the method's capability to reveal even subtle internal details of the package. The concept is extended to multichip and stacked-chip structures, where transfer impedances have to be introduced. Here, the dynamic properties of the package are important and complex impedance mapping is the proper way to characterize the package. KW - Thermal resistance KW - Temperature KW - Electrical resistance measurement KW - Impedance KW - Assembly KW - Semiconductor device packaging KW - Surface resistance KW - Measurement techniques KW - MOSFETs Y1 - 2005 U6 - https://doi.org/10.1109/STHERM.2005.1412198 SN - 1065-2221 SP - 313 EP - 321 PB - IEEE ER - TY - JOUR A1 - Puff, Simone A1 - Seidel, Uwe M. A1 - Steffens, Oliver T1 - Pflege- und intensivmedizinische Bereiche im EnEV-Bewertungsverfahren JF - Bauphysik N2 - Die Anwendbarkeit des derzeit gültigen Verfahrens zur energetischen Bewertung von Nichtwohngebäuden gemäß aktueller Energieeinsparverordnung (EnEV 2014) in Verbindung mit DIN V 18599 als Planungs- und Bewertungstool auf Pflege- und intensiv-medizinische Bereiche von Krankenhäusern wird an einem beispielhaften, mittelgroßen Krankenhaus untersucht. Der Fokus liegt dabei auf der Praktikabilität der Abbildung von thermischen Lasten und Raumzuständen durch die Normnutzungsprofile aus DIN V 18599 Teil 10 im Vergleich zu realen, vor Ort erfassten Nutzungsbedingungen. Weitere Betrachtungen in einer einfachen thermischen Simulation (TRNSYSlite) erlauben eine methodische Kritik in Bezug auf die Aussagekraft der nach Norm berechneten EnEV-Ergebnisse. Es werden Empfehlungen für Maßnahmen zur Verbesserung der energetischen Performance und der Behaglichkeit in Krankenhäusern im Bereich der Planung erarbeitet. T2 - Energetic Evaluation of care and critical care units of hospitals according to EnEV 2014 KW - Energieeinsparungsverordnung KW - Krankenhaus Y1 - 2015 U6 - https://doi.org/10.1002/bapi.201510036 VL - 37 IS - 6 SP - 307 ER - TY - JOUR A1 - Wensauer, Andreas A1 - Steffens, Oliver A1 - Suhrke, Michael A1 - Rössler, Ulrich T1 - Laterally coupled few-electron quantum dots JF - Physical Review B N2 - We present ground-state calculations for laterally coupled quantum dots containing 2, 4, and 8 electrons. As our emphasis is on spin effects our results are obtained by applying spin-density functional theory (SDFT). By varying the distance between the centers of the coupled quantum dots, the transition from weak to strong coupling situation is realized. For the 2-electron system we also apply the Heitler-London approximation and analytical concepts to check the reliability of SDFT calculations in this case. In addition we discuss the features of the Coulomb staircase of laterally coupled quantum dots in the weak and strong coupling regimes in comparison to that of a circular parabolic quantum dot. Y1 - 2000 U6 - https://doi.org/10.1103/PhysRevB.62.2605 VL - 62 IS - 4 SP - 2605 ER - TY - CHAP A1 - Steffens, Oliver ED - Trapp, Eugen T1 - "Grünes Denkmal" - Denkmalpflege und Erneuerbare Energien ergänzen sich T2 - Vorsicht Baudenkmal! Konfliktfelder Umwelt - Nutzung - Geschichte. Beiträge des 28. Regensburger Herbstsymposions für Kunst, Geschichte und Denkmalpflege vom 22. bis 24. November 2013 KW - Denkmalpflege KW - Denkmalschutz KW - Erneuerbare Energien Y1 - 2014 SN - 978-3-937527-77-2 SP - 9 EP - 17 PB - Regensburg CY - Morsbach-Verl. ER - TY - CHAP A1 - Steffens, Oliver A1 - Suhrke, Michael A1 - Rössler, Ulrich ED - Gershoni, David T1 - Correlation in few-electron quantum dots: Spin effects and spontaneous currents T2 - 24rd International Conference on the Physics of Semiconductors (ICPS 24), Jerusalem, Israel, August 2-7, 1998 Y1 - 1999 SN - 978-981-02-3613-7 PB - World Scientific CY - Singapore ER - TY - THES A1 - Gering, Stefan T1 - Thermische Detailsimulationen in der Bestandssanierung Y1 - 2014 CY - Regensburg ER - TY - JOUR A1 - Szabó, Peter A1 - Steffens, Oliver A1 - Lenz, Michael A1 - Farkas, Gábor T1 - Transient junction-to-case thermal resistance measurement methodology of high accuracy and high repeatability JF - IEEE Transactions on Components and Packaging Technologies N2 - High-power packages show a characteristic three-dimensional heat flow resulting in large lateral changes in chip and case surface temperature. This paper proposes an unambiguous definition for the R/sub thJC/ junction-to-case thermal resistance as a key parameter of such packages based on a transient measurement technique ensuring high repeatability even at very low R/sub th/ values. The technique is illustrated on thermal transient measurements of high-power MOSFET devices. It is also presented how the same measurement results can be used for die attach quality analysis. Finally, a comparative method is shown for measuring the differences of R/sub th/ values among samples with many times higher resolution compared with a direct R/sub thJC/ measurement. KW - Thermal resistance KW - Electrical resistance measurement KW - Temperature KW - Packaging KW - Cold plates KW - MOSFET circuits KW - Semiconductor device measurement KW - Surface resistance KW - Microassembly KW - Thermal conductivity Y1 - 2005 U6 - https://doi.org/10.1109/TCAPT.2005.859768 SN - 1521-3331 VL - 28 IS - 4 SP - 630 EP - 636 ER - TY - JOUR A1 - Mayrock, Oliver A1 - Mikhailov, Sergej A. A1 - Steffens, Oliver A1 - Rössler, Ulrich T1 - Observability of the acoustic plasma mode in double-layered quantum dots JF - Physica E: Low-dimensional Systems and Nanostructures N2 - Double-layered quantum dots represent a novel realization of a multi-component plasma system. By modelling the system and applying classical concepts we investigate the oscillator strength of the acoustic plasma mode and its dependence on the system parameters. In view of recent experimental results, we discuss the observability of this collective excitation. KW - Quantum dots KW - Collective excitations KW - Magneto-plasmon KW - Acoustic modes Y1 - 1997 U6 - https://doi.org/10.1016/S1386-9477(97)00048-9 VL - 1 IS - 1-4 SP - 232 EP - 234 ER -