@article{SykoraDiamantidisHolickyetal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Holick{\´y}, Milan and Markov{\´a}, Jana and R{\´o}zs{\´a}s, {\´A}rp{\´a}d}, title = {Assessment of compressive strength of historic masonry using non-destructive and destructive techniques}, series = {Construction and Building Materials}, volume = {193}, journal = {Construction and Building Materials}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.conbuildmat.2018.10.180}, pages = {196 -- 210}, abstract = {Masonry structures were built by various techniques using different materials, the properties of which exhibit a considerable scatter dependent on periods of construction and region-specific conditions. For historic structures with a heritage value, various non- or minor-destructive tests (NDTs) are commonly applied, while the application of destructive tests (DTs) is minimized. The contribution is based on investigations of 15 historic stone and clay brick masonry structures, for which NDT strengths of masonry units are verified by DTs. The proposed operational approach makes it possible to account for statistical uncertainty due to a limited number of DTs used to calibrate NDTs.}, language = {en} } @article{KasparRablMayer, author = {Kaspar, Marcel and Rabl, Hans-Peter and Mayer, Wolfgang}, title = {Ion-Molecule Reaction for the Selective Detection of Hydrocarbons in Diesel Exhaust Gas}, series = {Chemie Ingenieur Technik}, volume = {90}, journal = {Chemie Ingenieur Technik}, number = {6}, publisher = {WILEY-VCH}, doi = {10.1002/cite.201700075}, pages = {826 -- 834}, abstract = {The hydrocarbons present in the diesel exhaust gas are analyzed. A mass spectrometer is used for the measurements, and it operates on the basis of an ion-molecule reaction. This method is especially suitable because it is selective, is as free of fragments as possible, and is highly sensitive to the species that need to be measured. The study shows that numerous hydrocarbons in diesel exhaust gas can be identified. In particular, three molecules, ethyne, ethene and propene, were analyzed online in-depth on an engine test bench under different engine operating conditions.}, language = {en} } @article{SchorrBoehmZentneretal., author = {Schorr, Philipp and B{\"o}hm, Valter and Zentner, Lena and Zimmermann, Klaus}, title = {Motion characteristics of a vibration driven mobile tensegrity structure with multiple stable equilibrium states}, series = {Journal of Sound and Vibration}, volume = {437}, journal = {Journal of Sound and Vibration}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.jsv.2018.09.019}, pages = {198 -- 208}, abstract = {A novel type of a vibration driven motion system based on a compliant tensegrity structure with multiple stable equilibrium states is considered. These equilibrium configurations correspond to different prestress states with different dynamical properties. Therefore, the motion characteristics can be varied by changing the equilibrium state. For the application in the fields of mobile robotics, these discrete adjustable dynamics are advantageous. The vibration modes of the structure as well as the corresponding motion characteristics of the system can be adapted to the given environmental conditions in order to ensure a reliable motion. In this paper, dynamical investigations of an exemplary two-dimensional multistable tensegrity structure are considered. For the chosen parameter values the structure features two relevant equilibrium configurations. The resulting motion system is in contact to a horizontal plane due to gravity and the actuation is realized by the harmonic variation of the length of a single tensioned member. The motion of the system is simulated for various actuation frequencies with the different equilibrium states as an initial configuration. A uniaxial or a planar movement occurs depending on the selection of the actuated member within the tensegrity structure. The steady state motion is evaluated regarding motion characteristics like the steady state velocity. Moreover, the influences on the motion behavior caused by the different equilibrium states as an initial condition are emphasized. (C) 2018 Elsevier Ltd. All rights reserved.}, language = {en} } @article{daSilvaMotaHinckelRoccoetal., author = {da Silva Mota, Fabio Antonio and Hinckel, Jose Nivaldo and Rocco, Evandro Marconi and Schlingloff, Hanfried}, title = {Modeling and Analysis of a LOX/Ethanol Liquid Rocket Engine}, series = {Journal of Aerospace Technology and Management}, volume = {10}, journal = {Journal of Aerospace Technology and Management}, publisher = {Inst Aeronautica \& Espaco-IAE}, doi = {10.5028/jatm.v10.914}, abstract = {This work studies the performance and dry mass of the under development LOX/Ethanol L75 liquid rocket engine. To this end, an object-oriented program written in C++ was developed. The program is intended to be versatile and easily extensible in order to analyze different configurations of liquid rocket engines. The UML (Unified Modeling Language) tool is used to model the architecture of the codes. UML diagrams help to visualize the code structure and the communication between objects, enabling a high degree of abstraction. The cryogenics Vulcain and HM7B engines power cycles along with the staged-combustion SSME engine perform the verification of the codes. Finally, the influence of changes in design parameters on the performance and dry mass of the L75 rocket engine is analyzed.}, language = {en} } @article{BraunGebhardMatysiketal., author = {Braun, Peter and Gebhard, J{\"u}rgen and Matysik, Frank-Michael and Rabl, Hans-Peter}, title = {Potential Technical Approaches for Improving Low-Temperature NOx Conversion of Exhaust Aftertreatment Systems}, series = {Chemie Ingenieur Technik}, volume = {90}, journal = {Chemie Ingenieur Technik}, number = {6}, publisher = {WILEY-VCH}, doi = {10.1002/cite.201700122}, pages = {762 -- 773}, abstract = {Lean-burn engines, such as diesel engines, are widely used in mobile and stationary applications. Operation of lean-burn engines leads to formation of distinct amounts of nitrogen oxides (NO and NO2). Efficient aftertreatment is mandatory to meet legal requirements, especially at low exhaust temperatures, as for the future a decline of the exhaust temperature level can be predicted due to improved engine efficiencies. Within this review, potential technical solutions to enhance the DeNO(x)-aftertreatment efficiency at low exhaust temperatures are presented.}, language = {en} } @article{BarzSeligerMarxetal., author = {Barz, Tilman and Seliger, Dominik and Marx, Klemens and Sommer, Andreas and Walter, Sebastian F. and Bock, Hans Georg and Koerkel, Stefan}, title = {State and state of charge estimation for a latent heat storage}, series = {Control Engineering Practice}, volume = {72}, journal = {Control Engineering Practice}, publisher = {Pergamon-Elsevier d.}, doi = {10.1016/j.conengprac.2017.11.006}, pages = {151 -- 166}, abstract = {A nonlinear state observer is designed for a thermal energy storage with solid/liquid phase change material (PCM). Using a physical 2D dynamic model, the observer reconstructs transient spatial temperature fields inside the storage and estimates the stored energy and the state of charge. The observer has been successfully tested with a lab-scale latent heat storage with a single pass tube bundle and the phase change material located in a shell around each tube. It turns out that the observer robustly tracks the real process data with as few as four internal PCM temperature sensors. © 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{daSilvaMotaHinckelRoccoetal., author = {da Silva Mota, Fabio Antonio and Hinckel, Jose Nivaldo and Rocco, Evandro Marconi and Schlingloff, Hanfried}, title = {Trajectory Optimization of Launch Vehicles Using Object-oriented Programming}, series = {Journal of aerospace technology and management}, volume = {10}, journal = {Journal of aerospace technology and management}, publisher = {Institute of Aeronautics and Space}, doi = {10.5028/jatm.v10.948}, abstract = {The aim of this study is to model launch vehicles with focus on 3-DOF trajectory optimization using a modular approach. Despite the large number of operational launch vehicles, they usually consist of basic components and subsystems. In other words, a launch vehicle is an assembly of stages, which in turn is divided into propellant system and engine, and the engine is an assembly of basic components such as pumps, turbines, combustion chamber, and nozzle. To allow future extension and reuse of the codes, a modular structure using object-oriented programming is used. Two formulations of state equations of the trajectory and two optimization methods are described. The launch vehicle performance will be measured by payload mass for a given mission. The simulations of the VLS-1, Ariane 5 and VLS-Alfa were performed and showed good agreement with the literature.}, language = {en} } @article{GaertnerRablZink, author = {G{\"a}rtner, Uwe and Rabl, Hans-Peter and Zink, Uwe}, title = {Exhaust Gas Aftertreatment of the Future}, series = {MTZ worldwide}, volume = {79}, journal = {MTZ worldwide}, number = {7-8}, publisher = {Springer}, doi = {10.1007/s38313-018-0060-2}, pages = {70 -- 75}, language = {en} } @article{SchuemannMorichKaufholdetal., author = {Sch{\"u}mann, Malte and Morich, J. and Kaufhold, Tobias and B{\"o}hm, Valter and Zimmermann, Klaus and Odenbach, Stefan}, title = {A mechanical characterisation on multiple timescales of electroconductive magnetorheological elastomers}, series = {Magnetism and Magnetic Materials}, volume = {453}, journal = {Magnetism and Magnetic Materials}, number = {May}, publisher = {Elsevier}, doi = {10.1016/j.jmmm.2018.01.029}, pages = {198 -- 205}, abstract = {Magnetorheological elastomers are a type of smart hybrid material which combines elastic properties of a soft elastomer matrix with magnetic properties of magnetic micro particles. This leads to a material with magnetically controllable mechanical properties of which the magnetorheological effect is the best known. The addition of electroconductive particles to the polymer mix adds electrical properties to the material behaviour. The resulting electrical resistance of the sample can be manipulated by external magnetic fields and mechanical loads. This results in a distinct interplay of mechanical, electrical and magnetic effects with a highly complex time behaviour. In this paper a mechanical characterisation on multiple time scales was conducted to get an insight on the short and long-term electrical and mechanical behaviour of this novel material. The results show a complex resistivity behaviour on several timescales, sensitive to magnetic fields and strain velocity. The observed material exhibits fatigue and relaxation behaviour, whereas the magnetorheological effect appears not to interfere with the piezoresistive properties.}, language = {en} } @inproceedings{HacklHirschbergLexetal., author = {Hackl, Andreas and Hirschberg, Wolfgang and Lex, Cornelia and Rill, Georg}, title = {Tyre type dependent transient force behaviour by means of a maxwell model}, series = {The Dynamics of Vehicles on Roads and Tracks : Proceedings of the 25th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2017), Rockhampton, Queensland, Australia, 14-18 August 2017}, booktitle = {The Dynamics of Vehicles on Roads and Tracks : Proceedings of the 25th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2017), Rockhampton, Queensland, Australia, 14-18 August 2017}, editor = {Spiryagin, Maksym and Gordon, Timothy and Cole, Colin and McSweeney, Tim}, publisher = {CRC Press}, address = {London}, isbn = {1351057170}, doi = {10.1201/9781315265506}, pages = {157 -- 162}, abstract = {The present papers deals with the usability of an extended Maxwell model to describe the tyre dynamics during transient driving manoeuvres. In the present article, the para-metrisation process of a dynamic tyre model is investigated in a first step, using measurement data of tyre forces from a flat trac tyre test bench, (IABG 2016). Two tyre types of dimensions 255/50 R19 and 175/55 R15 are used. The practical applicability is discussed, considering the measurement procedure and the parameter optimisation process. In a second step, the performance of the dynamic tyre model is validated using measurements of manoeuvres under higher dynamic excitation. As a last step, an outlook is given on further research planned in which the presented model and parametrisation are adapted to a larger frequency range.}, language = {en} } @inproceedings{BresinskyReusner, author = {Bresinsky, Markus and Reusner, Florian}, title = {GLOBE - Learn and Innovate Digitization by a Virtual Collaboration Exercise and Living Lab}, series = {Interactivity, Game Creation, Design, Learning, and Innovation. 6th International Conference, ArtsIT 2017, and Second International Conference, DLI 2017, Heraklion, Crete, Greece, October 30-31, 2017, Proceedings}, booktitle = {Interactivity, Game Creation, Design, Learning, and Innovation. 6th International Conference, ArtsIT 2017, and Second International Conference, DLI 2017, Heraklion, Crete, Greece, October 30-31, 2017, Proceedings}, publisher = {Springer Nature}, doi = {10.1007/978-3-319-76908-0_26}, pages = {273 -- 281}, abstract = {This paper presents an advanced interactive learning platform .dot that implements the GLOBE exercise, using innovative information and communication technologies to enhance learning and development of management and leadership skills in a complex organizational setting. GLOBE on the one hand focuses on competences around ICT and virtual collaboration, and on the other hand on digital transformation, technologies and tools at higher education institutions. By this applied science, learning and developing on the real-world platform, analysis and drive of digital innovation and transformation can be fostered. The main goal is to co-create knowledge and solutions in the following focused subjects: Management and leadership of multidisciplinary, multinational and multicultural virtual and real collaboration in a complex organizational environment. GLOBE uses real world scenarios (e.g. United Nations mission) and involves real world actors. This comprehensive educational approach should enhance learning techniques and leverage learning progress with hands-on experiences and applied science in the context of ICT and virtual collaboration, and the embodied dynamics of behavior to support innovation and development.}, language = {en} } @inproceedings{KoderZacherlRabletal., author = {Koder, Alexander and Zacherl, Florian and Rabl, Hans-Peter and Mayer, Wolfgang and Gruber, Georg and Dotzer, Thomas}, title = {Jatropha Oil as an Alternative Fuel for Modern Diesel Engines - Injection Characteristics and EGR-Compatibility}, series = {WCX 17: SAE World Congress 2017}, booktitle = {WCX 17: SAE World Congress 2017}, publisher = {SAE International}, doi = {10.4271/2017-01-5000}, abstract = {An effective way to reduce greenhouse gas emissions (GHGs) is to use rurally produced straight jatropha oil as a substitute for diesel fuel. However, the different physical and chemical properties of straight vegetable oils (SVOs) require a customized setup of the combustion engine, particularly of the injection timing and quantity. Therefore, this study demonstrates the differences in the injection and combustion processes of jatropha oil compared to diesel fuel, particularly in terms of its compatibility with exhaust gas recirculation (EGR). A 2.2 l common-rail diesel engine with a two-stage turbocharging concept was used for testing. To examine the differences in injection rate shaping of diesel fuel and jatropha oil, the injector was tested with an injection rate analyzer using both the fuels. To investigate the combustion process, the engine was mounted at an engine test bench and equipped with a cylinder pressure indication system. All limited emissions, as well as fuel consumption, were measured. Various injection strategies, boost and rail pressure levels were tested at different EGR rates in terms of their impact on the combustion process. EGR in particular offers a great potential in the case of jatropha oil combustion due to its oxygen content. In addition, the investigation of injection rate shaping in combination with cylinder pressure analysis allowed a detailed thermodynamic evaluation of the combustion process. Ignition delay (ID) was also analyzed using a new method to calculate the start of combustion (SOC)}, language = {en} } @incollection{SoergelRiedererHeldetal., author = {S{\"o}rgel, Matthias and Riederer, Michael and Held, Andreas and Plake, Daniel and Zhu, Zhilin and Foken, Thomas and Meixner, Franz X.}, title = {Trace Gas Exchange at the Forest Floor}, series = {Energy and Matter Fluxes of a Spruce Forest Ecosystem}, volume = {229}, booktitle = {Energy and Matter Fluxes of a Spruce Forest Ecosystem}, editor = {Foken, Thomas}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-49387-9}, doi = {10.1007/978-3-319-49389-3_8}, pages = {157 -- 179}, abstract = {Exchange conditions at the forest floor are complex due to the heterogeneity of sources and sinks and the inhomogeneous radiation but are important for linking soil respiration to measurements in the trunk space or above canopy. Far more attention has therefore been paid to above and within canopy flows, but even studies that addressed forest floor exchange do not present measurements below 1 m or 2 m. We used a multilayer model that explicitly resolves the laminar layer, the buffer layer, and the turbulent layer to calculate fluxes from the measured profiles in the lowest meter above ground and to calculate effective surface concentrations from given fluxes. The calculated fluxes were compared to measured eddy covariance fluxes of sensible heat and O3 and to chamber derived soil fluxes of CO2 and 222Rn. Sensible heat fluxes agreed surprisingly well given the heterogeneity of radiative heating and the generally low fluxes (max. 25 W m-2). The chamber fluxes turned out to be not comparable as the chamber fluxes were too low, probably due to one of the well-known problems of enclosures such as pressure differences, disturbed gradients and exclusion of naturally occurring turbulence events and surface cooling. The O3 fluxes agreed well for high O3 values reaching down to the forest floor during full coupling of the canopy by coherent structures. During most of the time, the model overestimated the fluxes as chemical reactions were dominating within the profile. One new approach was to calculate the effective surface concentration from a given flux and compare this to measured surface concentrations. This allowed the identification of situations with a coupled and decoupled forest floor layer, which has important consequences for respiration measurements in the trunk space or above canopy and should be considered in upcoming studies.}, language = {en} } @book{OPUS4-4015, title = {Energiespeicher - Bedarf, Technologien, Integration}, editor = {Sterner, Michael and Stadler, Ingo}, edition = {2. korrigierte und erg{\"a}nzte Auflage}, publisher = {Springer}, address = {Berlin, Heidelberg}, isbn = {978-3-662-48892-8}, doi = {10.1007/978-3-662-48893-5}, abstract = {Die Autoren dieses Werkes geben einen umfassenden {\"U}berblick {\"u}ber die verschiedenen Aspekte der Energiespeicherung. Sie beschreiben zun{\"a}chst die Bedeutung von Energiespeichern in der Energieversorgung und definieren ihre Rolle darin. Dann gehen sie auf den Speicherbedarf in der Strom-, W{\"a}rme- und Kraftstoffversorgung im Kontext der Energiewende ein. Im Hauptteil werden die verschiedenen Speichertechnologien ausf{\"u}hrlich vorgestellt sowie ihre Vor- und Nachteile diskutiert. Praktische Anwendungsbeispiele und die Integration von Speichern {\"u}ber alle Energiesektoren hinweg runden das Buch ab. Zahlreiche Grafiken und Beispiele veranschaulichen das gesamte Feld der Energiespeicher und sind als Erg{\"a}nzung mehrsprachig online in Farbe verf{\"u}gbar. Die 2. Auflage enth{\"a}lt ein neues Kapitel zu den rechtlichen Rahmenbedingungen, neue Studien zum Speicherbedarf, Power-to-X f{\"u}r die chemische Industrie, neue LOHC- und Lageenergiespeicher sowie neueste Trends zu Kostenentwicklung und Batterieanwendungen. „Endlich ein umfassendes Buch zur Energiewende, das auch f{\"u}r technische Laien verst{\"a}ndlich und inspirierend geschrieben ist." Franz Alt, Journalist und Buchautor „Das großartige Werk sei allen empfohlen, die sich wirklich f{\"u}r die Zukunft unseres Landes interessieren. Es zeigt auf eindrucksvolle Weise: Es wird nicht einfach, aber wir schaffen das." Prof. Dr. Harald Lesch, Physiker und Fernsehmoderator}, language = {de} } @incollection{Sterner, author = {Sterner, Michael}, title = {Power-to-Gas}, series = {Handbook of Climate Change Mitigation and Adaptation}, booktitle = {Handbook of Climate Change Mitigation and Adaptation}, editor = {Chen, Wei-Yin and Suzuki, Toshio and Lackner, Maximilian}, edition = {2}, publisher = {Springer VS}, address = {Cham}, isbn = {978-3-319-14408-5}, doi = {10.1007/978-3-319-14409-2_89}, pages = {2775 -- 2825}, abstract = {This chapter provides an overview on the storage technology power-to-gas for the decarbonization of all energy sectors. Other than "negative emissions" with CCS or biomass, which have clear limits in potentials, costs and environmental benefits, storage and energy conversion technologies like power-to-gas and power-to-x enable the decarbonization by neutralizing the CO2 footprint of all energy services. Via the conversion of renewable electricity into chemical energy carriers like renewable hydrogen or renewable hydrocarbons, the existing fossil infrastructure with vast and sufficient storage and transport capacities can be used with carbon neutral renewable energy. After showing the demand for storage technologies, the technology components of power-to-gas are described, building the basis for the storage system power-to-gas itself that is described in detail, including efficiency, potential, CO2 emissions, and costs. In conclusion, a technical pathway of decarbonization including costs is described for the industrial nation of Germany and necessary policy frameworks are derived.}, language = {en} } @incollection{SternerThema, author = {Sterner, Michael and Thema, Martin}, title = {Vergleich der Speichersysteme}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_12}, pages = {645 -- 682}, subject = {Energiespeicher}, language = {de} } @incollection{SternerStadlerEckertetal., author = {Sterner, Michael and Stadler, Ingo and Eckert, Fabian and Gerhardt, Norman and von Olshausen, Christian and Thema, Martin and Trost, Tobias}, title = {Speicherintegration zur Kopplung unterschiedlicher Energiesektoren}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_14}, pages = {769 -- 818}, subject = {Energieversorgung}, language = {de} } @incollection{SternerBreuerDreesetal., author = {Sterner, Michael and Breuer, Christopher and Drees, Tim and Eckert, Fabian and Maaz, Andreas and Pape, Carsten and Rotering, Niklas and Thema, Martin}, title = {Speicherbedarf in der Stromversorgung}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_3}, pages = {53 -- 140}, subject = {Speicherbedarf}, language = {de} } @incollection{SternerEckertGerhardtetal., author = {Sterner, Michael and Eckert, Fabian and Gerhardt, Norman and Henning, Hans-Martin and Palzer, Andreas}, title = {Speicherbedarf in der W{\"a}rmeversorgung}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_4}, pages = {141 -- 168}, subject = {Energiespeicher}, language = {de} } @incollection{SternerStadlerEckertetal., author = {Sterner, Michael and Stadler, Ingo and Eckert, Fabian and Thema, Martin}, title = {Speicherintegration in einzelnen Energiesektoren}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_13}, pages = {685 -- 767}, subject = {Energiespeicher}, language = {de} } @incollection{StadlerEckert, author = {Stadler, Ingo and Eckert, Fabian}, title = {Lastmanagement als Energiespeicher}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, editor = {Sterner, Michael and Stadler, Ingo}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_11}, pages = {619 -- 644}, subject = {Lastverteilung }, language = {de} } @incollection{SternerStadler, author = {Sterner, Michael and Stadler, Ingo}, title = {Energiespeicher im Wandel der Zeit}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_1}, pages = {3 -- 24}, subject = {Energiespeicher}, language = {de} } @article{TrostSternerBruckner, author = {Trost, Tobias and Sterner, Michael and Bruckner, Thomas}, title = {Impact of electric vehicles and synthetic gaseous fuels on final energy consumption and carbon dioxide emissions in Germany based on long-term vehicle fleet modelling}, series = {Energy}, volume = {141}, journal = {Energy}, publisher = {Elsevier}, issn = {0360-5442}, doi = {10.1016/j.energy.2017.10.006}, pages = {1215 -- 1225}, abstract = {Based on a prospective scenario analysis, possible vehicle fleet developments for the individual motor car traffic (vehicle categories N1 and M1) are investigated for Germany in order to determine the long-term vehicle fleet structure, final energy demand, and related carbon dioxide emissions until the year 2050. In this framework, a vehicle fleet model was developed which combines a bottom-up consumer demand model with a dynamic stock-flow approach. Special emphasis is thereby given to different electric power-trains and synthetic gaseous fuels based on the power-to-gas technology. In detail, two different main scenarios are developed and, in addition, the impact of different carbon dioxide taxation levels of fossil fuels on the vehicle fleet structure are analysed. The scenario results reveal a broad range of possible future vehicle fleet structures. In the short to medium timeframe, the internal combustion engine dominates the fleet as a result of efficiency improvements and an increased use of natural gas as automotive fuel. The development of electric power-trains is initially marked by hybrid vehicles, whereas battery electric vehicles dominate the fleet structure in the long-term. Under favourable conditions, also synthetic gaseous fuels are competitive which can reduce carbon dioxide emissions even further.}, language = {en} } @inproceedings{GrimmHaumer, author = {Grimm, Alexander and Haumer, Anton}, title = {EMOTH The EMobility Library of OTH Regensburg}, series = {Proceedings of the 12th International Modelica Conference, Prague, Czech Republic, May 15-17, 2017}, booktitle = {Proceedings of the 12th International Modelica Conference, Prague, Czech Republic, May 15-17, 2017}, publisher = {Link{\"o}ping University Electronic Press}, doi = {10.3384/ecp17132285}, pages = {285 -- 290}, abstract = {The importance of E-Mobility is rapidly increasing, not only for private vehicle traffic but also for public transport. In and around Regensburg, Germany there are a lot of automotive companies. Therefore E-Mobility is an important topic in the curriculum of several courses of study at the East-Bavarian Technical University of Applied Sciences Regensburg (OTH). One Master of Applied Research student at OTH has chosen the topic to develop an open-source simulation tool for electric vehicles - the EMOTH Library - based on Modelica and to refine several aspects of the library during the one and a half year of the master course. After one semester, the basic version of the library is available and will be presented in this paper.}, language = {en} } @article{DechantFedulovFetisovetal., author = {Dechant, Eduard and Fedulov, Feodor and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {Bandwidth Widening of Piezoelectric Cantilever Beam Arrays by Mass-Tip Tuning for Low-Frequency Vibration Energy Harvesting}, series = {Applied Science}, volume = {7}, journal = {Applied Science}, number = {12}, publisher = {MDPI}, organization = {MDPI AG}, doi = {10.3390/app7121324}, abstract = {Wireless sensor networks usually rely on internal permanent or rechargeable batteries as a power supply, causing high maintenance efforts. An alternative solution is to supply the entire system by harvesting the ambient energy, for example, by transducing ambient vibrations into electric energy by virtue of the piezoelectric effect. The purpose of this paper is to present a simple engineering approach for the bandwidth optimization of vibration energy harvesting systems comprising multiple piezoelectric cantilevers (PECs). The frequency tuning of a particular cantilever is achieved by changing the tip mass. It is shown that the bandwidth enhancement by mass tuning is limited and requires several PECs with close resonance frequencies. At a fixed frequency detuning between subsequent PECs, the achievable bandwidth shows a saturation behavior as a function of the number of cantilevers used. Since the resonance frequency of each PEC is different, the output voltages at a particular excitation frequency have different amplitudes and phases. A simple power-transfer circuit where several PECs with an individual full wave bridge rectifier are connected in parallel allows one to extract the electrical power close to the theoretical maximum excluding the diode losses. The experiments performed on two- and three-PEC arrays show reasonable agreement with simulations and demonstrate that this power-transfer circuit additionally influences the frequency dependence of the harvested electrical power.}, language = {en} } @article{ChatzitakisDawoud, author = {Chatzitakis, Paris and Dawoud, Belal}, title = {An alternative approach towards absorption heat pump working pair screening}, series = {Renewable Energy}, volume = {110}, journal = {Renewable Energy}, publisher = {Pergamon-Elsevier}, organization = {PERGAMON-ELSEVIER SCIENCE LTD}, doi = {10.1016/j.renene.2016.08.014}, pages = {47 -- 58}, abstract = {The successful market penetration of modern absorption heat pumps (AHP) today is critically dependent on their thermodynamic performance as well as other key factors like cost, reliability and inherent safety. Conventional AHPs have a proven record in the first two aspects but crucial shortcomings in the last two. For this reason it has been imperative to search for alternative working pairs that could potentially provide comparable performance while also satisfying the rest of the conditions to the best extent possible. As part of a systematic approach towards this direction, a detailed cycle analysis was performed, utilizing an idealized AHP system containing a real working pair, which enabled the identification of five dimensionless parameters and key thermophysical properties that influence the system's thermodynamic efficiency and the circulation ratio. In order to validate those findings, these parameters were calculated and compared between conventional and alternative AHP refrigerants. It turned out that low molecular weight ratios between absorbent and refrigerant have a beneficial effect on both coefficient of performance and the circulation ratio. Furthermore, both the refrigerant acentric factor and the absorbent vaporization enthalpy shall be minimized to obtain better performance. (C) 2016 Elsevier Ltd. All rights reserved.}, language = {en} } @inproceedings{SailerDeubzerLuettgenetal., author = {Sailer, Andreas and Deubzer, Michael and L{\"u}ttgen, Gerald and Mottok, J{\"u}rgen}, title = {Comparing Trace Recordings of Automotive Realtime Software}, series = {RTNS '17: Proceedings of the 25th International Conference on Real-Time Networks and Systems, Grenoble, France, IEEE}, booktitle = {RTNS '17: Proceedings of the 25th International Conference on Real-Time Networks and Systems, Grenoble, France, IEEE}, doi = {10.1145/3139258.3139265}, pages = {118 -- 127}, abstract = {The process of engineering models of existing real-time system components is often difficult and time consuming, especially when legacy code has to be re-used or information about the exact timing behaviour is needed. In order to tackle this reverse engineering problem, we have developed the tool CoreTAna. CoreTAna derives an AUTOSAR compliant model of a real-time system by conducting dynamic analysis using trace recordings. Motivated by the challenge of assessing the quality of reverse engineered models of real-time software, we present a novel mathematical measure for comparing trace recordings from embedded real-time systems regarding their temporal behaviour. We also introduce a benchmark framework based on this measure, for evaluating reverse engineering tools such as CoreTAna. This considers common system architectures and also includes randomly generated systems and three systems of industrial automotive projects. Finally, an industrial case study demonstrates other use cases of our measure, such as impact analysis.}, language = {en} } @inproceedings{NonnParedesNordhagenetal., author = {Nonn, Aida and Paredes, Marcelo and Nordhagen, H. O. and Munkejord, S. T. and Wierzbicki, Tomasz}, title = {Challenges in fluid-structure modeling of crack propagation and arrest in modern steel pipelines}, series = {14th International Congress on Fracture (ICF14), 18-23 June 2017, Rhodes, Greece}, booktitle = {14th International Congress on Fracture (ICF14), 18-23 June 2017, Rhodes, Greece}, pages = {1351 -- 1352}, language = {en} } @inproceedings{BrunnerRoederKuceraetal., author = {Brunner, Stefan and R{\"o}der, J{\"u}rgen and Kucera, Markus and Waas, Thomas}, title = {Automotive E/E-architecture enhancements by usage of ethernet TSN}, series = {13th Workshop on Intelligent Solutions in Embedded Systems (WISES), 12-13 June 2017, Hamburg, Germany}, booktitle = {13th Workshop on Intelligent Solutions in Embedded Systems (WISES), 12-13 June 2017, Hamburg, Germany}, publisher = {IEEE}, doi = {10.1109/WISES.2017.7986925}, pages = {9 -- 13}, abstract = {A huge upheaval emerges from the transition to autonomous vehicles in the domain of road vehicles, ongoing with a change in the vehicle architecture. Many sensors and Electronic Control Units are added to the current vehicle architecture and further safety requirements like reliability become even more necessary. In this paper we present a potential evolution of the Electrical/Electronic-Architecture, including a Zone Architecture, to enable future functionality. We reveal the impact on the communication network concerning these architectures and present a potential communication technology to facilitate such architectures.}, subject = {Kraftfahrzeug}, language = {en} } @article{KalitaSnarskiiShamoninChamonineetal., author = {Kalita, Viktor M. and Snarskii, Andrei A. and Shamonin (Chamonine), Mikhail and Zorinets, Denis}, title = {Effect of single-particle magnetostriction on the shear modulus of compliant magnetoactive elastomers}, series = {Physical review E}, volume = {95}, journal = {Physical review E}, number = {3}, publisher = {American Physical Society}, doi = {10.1103/PhysRevE.95.032503}, abstract = {The influence of an external magnetic field on the static shear strain and the effective shear modulus of a magnetoactive elastomer (MAE) is studied theoretically in the framework of a recently introduced approach to the single-particle magnetostriction mechanism [V. M. Kalita et al., Phys. Rev. E 93, 062503 (2016)]. The planar problem of magnetostriction in an MAE with magnetically soft inclusions in the form of a thin disk (platelet) having the magnetic anisotropy in the plane of this disk is solved analytically. An external magnetic field acts with torques on magnetic filler particles, creates mechanical stresses in the vicinity of inclusions, induces shear strain, and increases the effective shear modulus of these composite materials. It is shown that the largest effect of the magnetic field on the effective shear modulus should be expected in MAEs with soft elastomer matrices, where the shear modulus of the matrix is less than the magnetic anisotropy constant of inclusions. It is derived that the effective shear modulus is nonlinearly dependent on the external magnetic field and approaches the saturation value in magnetic fields exceeding the field of particle anisotropy. It is shown that model calculations of the effective shear modulus correspond to a phenomenological definition of effective elastic moduli and magnetoelastic coupling constants. The obtained theoretical results compare well with known experimental data. Determination of effective elastic coefficients in MAEs and their dependence on magnetic field is discussed. The concentration dependence of the effective shear modulus at higher filler concentrations has been estimated using the method of Pade approximants, which predicts that both the absolute and relative changes of the magnetic-field-dependent effective shear modulus will significantly increase with the growing concentration of filler particles.}, language = {en} } @article{FuhrmannMottok, author = {Fuhrmann, Thomas and Mottok, J{\"u}rgen}, title = {Ethical, intercultural and professional impulses integrated into a transmission systems lecture}, series = {2017 IEEE Global Engineering Education Conference (EDUCON), 25-28 April 2017, Athens, Greece}, journal = {2017 IEEE Global Engineering Education Conference (EDUCON), 25-28 April 2017, Athens, Greece}, publisher = {IEEE}, doi = {10.1109/EDUCON.2017.7942829}, pages = {92 -- 95}, abstract = {In the sixth semester of the bachelor study course "Electrical Engineering and Information Technology", a lecture "Transmission Systems" is given. It explains basic principles, circuits and systems of electrical and optical transmission systems. Short intellectual impulses, which address professional, intercultural and ethical issues of engineers' working life are integrated into this regular lecture. In each lecture unit, an impulse with one specific topic is given approximately in the middle of the lecture hour. An evaluation was done at the end of the semester, which shows that most of the students remember the discussed topics and state high interest due to high importance for their professional life. Due to these encouraging results, this concept will be developed further.}, language = {en} } @article{SteinkirchnerFuhrmannNiemetz, author = {Steinkirchner, Alfons and Fuhrmann, Thomas and Niemetz, Michael}, title = {Channel Coded Processor for Enhanced Safety}, series = {International Journal of Future Computer and Communication (IJFCC)}, volume = {6}, journal = {International Journal of Future Computer and Communication (IJFCC)}, number = {2}, publisher = {International Association of Computer Science and Information}, address = {Singapore}, issn = {2010-3751}, doi = {10.18178/ijfcc.2017.6.2.489}, pages = {58 -- 62}, abstract = {Several concepts are known for improving processor safety, all of them having their pros and cons. Some are very resource intensive, others have limited capabilities regarding the provided error safety. In this paper we use research on channel coding of noisy communication channels known from communication theory as an analogy to random bit errors in processors. We incorporate this knowledge into processor design to suggest a new error correction concept by using channel coding in processors. The new concept of a Channel Coded Processor could provide effective implementation of redundancy by the channel coding that enables error correction. The concept could also create a complete chain of redundancy in all areas and components of the processor ranging from the code compiler through the processing hardware to the output of the information.}, language = {en} } @inproceedings{DiamantidisLenziSykora, author = {Diamantidis, Dimitris and Lenzi, Daniele and S{\´y}kora, Miroslav}, title = {Optimal decisions based on monitoring - case study of steel roof}, series = {Proceedings of the Joint COST TU1402-TU1406 - IABSE WC1 Workshop, Zagreb 2-3 March 2017}, booktitle = {Proceedings of the Joint COST TU1402-TU1406 - IABSE WC1 Workshop, Zagreb 2-3 March 2017}, doi = {10.5592/CO/BSHM2017.4.7}, pages = {4.7-1 -- 4.7-7}, abstract = {Monitoring of structures and related decisions based on cost optimization are discussed in this contribution. Many research publications and experimental data are currently available on inspection and on monitoring and they represent the outcome of the remarkable work done. Not all the topics of interest are widely debated and implemented in standards. The current state-of-practice in standards is summarized and aspects to be included in future recommendations are proposed. The implementation of risk-based decisions is illustrated in a case study dealing with a stadium roof in Northern Italy. Snow actions are important especially in northern and mountainous regions where heavy snowfalls and related accumulation result to considerable loads. As the roof structure fails to comply with the requirements of Eurocodes, a permanent monitoring system has been installed to allow for real time evaluation of the reliability level of the structure. The system supplies the necessary information supporting immediate decisions on closure of the stadium in case of an extraordinary snow load. Cost-optimal decisions regarding the closure of the stadium are analysed based on a limit state function, on probabilistic models for the influencing parameters including measurement uncertainty, economic losses related to closure and failure consequences. The results demonstrate the potential of the use of the monitoring systems and probabilistic reliability analysis in order to support decisions and highlight the need for their implementation in future standards.}, language = {en} } @inproceedings{Neidhart, author = {Neidhart, Thomas}, title = {Bodenphysikalische und bodenmechanische Anforderungen an ZFSV (Fl{\"u}ssigboden) als Bettungsmaterialien erdverlegter Hochspannungsleitungen}, series = {Rohrleitungen in digitalen Arbeitswelten : Tagungsband zum 31. Oldenburger Rohrleitungsforum 2017}, booktitle = {Rohrleitungen in digitalen Arbeitswelten : Tagungsband zum 31. Oldenburger Rohrleitungsforum 2017}, editor = {Wegener, Thomas}, publisher = {Vulkan Verlag}, address = {Essen}, isbn = {978-3-8027-2865-5}, pages = {337}, language = {de} } @inproceedings{GrothmannPoelsterlGerling, author = {Grothmann, Benjamin and Poelsterl, Thomas and Gerling, Dieter}, title = {Online compensation of current sensor gain-faults for safety-relevant IPM-drives}, series = {2017 IEEE Transportation Electrification Conference and Expo (ITEC), 22-24 June 2017, Chicago, IL, USA}, booktitle = {2017 IEEE Transportation Electrification Conference and Expo (ITEC), 22-24 June 2017, Chicago, IL, USA}, publisher = {IEEE}, doi = {10.1109/ITEC.2017.7993355}, pages = {701 -- 706}, abstract = {Detection and compensation of current sensor gain-faults regardless of the operating-point is a crucial aspect for safety-relevant servo-drives. This paper presents and investigates a new direct phase-gain re-balancing methodology, especially suited for interior permanent magnet machine (IPM) drives mostly operating at low speed-ranges including standstill. The proposed model-based approach utilizes high-frequency signal-injection (HFI) to facilitate fast and persistent sensor monitoring for any operating state of the drive. No additional sensing hardware is required. Extraction of the HFI-phase-current response enables detection and immediate compensation of sensor gain-faults. Implementation aspects of the proposed concept are discussed thoroughly. Experimental results are presented to prove and investigate robustness, reliability and fault-tolerant performance.}, language = {en} } @inproceedings{HacklHirschbergLexetal., author = {Hackl, Andreas and Hirschberg, Wolfgang and Lex, Cornelia and Rill, Georg}, title = {Parameterization Process of the Maxwell Model to Describe the Transient Force Behavior of a Tire}, series = {WCX 17: SAE World Congress Experience 2017}, booktitle = {WCX 17: SAE World Congress Experience 2017}, publisher = {SAE}, doi = {10.4271/2017-01-1505}, abstract = {The present technical article deals with the modeling of dynamic tire forces, which are relevant during interactions of safety relevant Advanced Driver Assistance Systems (ADAS). Special attention has been paid on simple but effective tire modeling of semi-physical type. In previous investigations, experimental validation showed that the well-known first-order Kelvin-Voigt model, described by a spring and damper element, describes good suitability around fixed operation points, but is limited for a wide working range. When aiming to run vehicle dynamics models within a frequency band of excitation up to 8 Hz, these models deliver remarkable deviations from measured tire characteristics. To overcome this limitation, a nonlinear Maxwell spring-damper element was introduced which is qualified to model the dynamic hardening of the elastomer materials of the tire. However, the advantage of a more realistic description of the transient behavior leads to a more complex parametrization process. Therefore, in the proposed article attention is paid to describe the identification process including defined maneuvers to parameterize the tire model, where the accuracy of the parameter strongly depends on the quality of the available input data from measurement. In order to study this important aspect of parameterization, the reference data from simulation of the full physical tire model FTire is applied like a "virtual measurement" of specified testing maneuvers. The procedure of simulation by means of the enhanced first order dynamics model is implemented by the semi-physical tire model TMeasy. Finally, the improvements of the extended model are discussed and an outlook for future work is given.}, language = {en} } @article{DechantFedulovChashinetal., author = {Dechant, Eduard and Fedulov, Feodor and Chashin, Dmitri V. and Fetisov, Leonid Y. and Fetisov, Yuri K. and Shamonin (Chamonine), Mikhail}, title = {Low-frequency, broadband vibration energy harvester using coupled oscillators and frequency up-conversion by mechanical stoppers}, series = {Smart Materials and Structures}, volume = {26}, journal = {Smart Materials and Structures}, number = {6}, publisher = {IOP Publishing}, doi = {10.1088/1361-665X/aa6e92}, abstract = {The frequencies of ambient vibrations are often low (below 30 Hz). A broadband (3 dB bandwidth is larger than 10 Hz at an acceleration amplitude of 9.81 m s(-2)) vibration based energy harvester is proposed for transducing mechanical energy at such low frequencies into electrical energy. The mechanical setup converts low frequency mechanical vibrations into high frequency resonance oscillations of the transducer. This conversion is done by mechanical impacts on two mechanical stoppers. The originality of the presented design is that both low-frequency and high-frequency oscillators are permanently mechanically coupled. In the equivalent mechanical circuit, this coupling is achieved by connecting the ends of the stiff spring to both seismic masses, whereas one seismic mass (collison member) is also attached to the soft spring used as the constitutive element of a low-frequency oscillator. Further, both mechanical oscillators are not realized as conventional cantilever beams. In particular, the high frequency oscillator with the natural frequency of 340 Hz is a disc-shaped diaphragm with attached piezoelectric elements and a seismic mass. It is shown that it is possible to convert mechanical vibrations with acceleration amplitude of 9.81 m s(-2) in the region between approximately 7 and 25 Hz into electrical power larger than 0.1 mW with the maximum value of 0.8 mW. A simplified mathematical model based on piecewise linear coupled oscillators shows good agreement with experimental results. The ways to enhance the performance of the harvester and improve agreement with experiments are discussed.}, language = {en} } @article{SorokinStepanovShamoninChamonineetal., author = {Sorokin, Vladislav V. and Stepanov, Gennady V. and Shamonin (Chamonine), Mikhail and Monkman, Gareth J. and Kramarenko, Elena Yu}, title = {Magnetorheological behavior of magnetoactive elastomers filled with bimodal iron and magnetite particles}, series = {Smart materials and structures}, volume = {26}, journal = {Smart materials and structures}, number = {3}, publisher = {IOP Publishing}, doi = {10.1088/1361-665X/26/3/035019}, abstract = {Magnetoactive elastomers (MAE) based on soft silicone matrices, filled with various proportions of large diameter ( approximately 50 mu m) iron and small diameter ( approximately 0.5 mu m) magnetite particles are synthesized. Their rheological behavior in homogeneous magnetic fields up to 600 mT is studied in detail. The addition of small magnetite particles facilitates fabrication of uniformly distributed magnetic elastomer composites by preventing aggregation and sedimentation of large particles during curing. It is shown that using the proposed bimodal filler particles it is possible to tailor various magnetorheological (MR) properties which can be useful for different target applications. In particular, either absolute or relative magnetorheological effects can be tuned. The value of the damping factor as well as the range of deformation amplitudes for the linear viscoelastic regime can be chosen. The interdependencies between different MR properties of bimodal MAEs are considered. The results are discussed in the model framework of particle network formation under the simultaneous influence of external magnetic fields and mechanical deformation.}, language = {en} } @article{NiemetzHaenninenSchoepe, author = {Niemetz, Michael and H{\"a}nninen, Risto and Schoepe, Wilfried}, title = {On the Transition from Potential Flow to Turbulence Around a Microsphere Oscillating in Superfluid 4He}, series = {Journal of low temperature physics}, volume = {187}, journal = {Journal of low temperature physics}, number = {3-4}, publisher = {Springer Nature}, doi = {10.1007/s10909-017-1745-7}, pages = {195 -- 220}, abstract = {The flow of superfluid around a translationally oscillating sphere, levitating without mechanical support, can either be laminar or turbulent, depending on the velocity amplitude. Below a critical velocity that scales as and is temperature independent below 1 K, the flow is laminar (potential flow). Below 0.5 K, the linear drag force is caused by ballistic phonon scattering that vanishes as until background damping, measured in the empty cell, becomes dominant for K. Increasing the velocity amplitude above leads to a transition from potential flow to turbulence, where the large turbulent drag force varies as . In a small velocity interval \% above , the flow is unstable below 0.5 K, switching intermittently between both patterns. From time series recorded at constant temperature and driving force, the lifetimes of both phases are analyzed statistically. We observe metastable states of potential flow which, after a mean lifetime of 25 min, ultimately break down due to vorticity created by natural background radioactivity. The lifetimes of the turbulent phases have an exponential distribution, and the mean increases exponentially with . We investigate the frequency at which the vortex rings are shed from the sphere. Our results are compared with recent data of other authors on vortex shedding by moving a laser beam through a Bose-Einstein condensate. Finally, we show that our observed transition to turbulence belongs to the class of "supertransient chaos" where lifetimes of the turbulent states increase faster than exponentially.}, language = {en} } @article{PalombaDawoudSapienzaetal., author = {Palomba, Valeria and Dawoud, Belal and Sapienza, Alessio and Vasta, Salvatore and Frazzica, Andrea}, title = {On the impact of different management strategies on the performance of a two-bed activated carbon/ethanol refrigerator: An experimental study}, series = {Energy conversion and management}, volume = {142}, journal = {Energy conversion and management}, publisher = {Elsevier}, doi = {10.1016/j.enconman.2017.03.055}, pages = {322 -- 333}, abstract = {In the present work, an experimental study on a lab-scale adsorption refrigerator, based on activated carbon/ethanol working pair is reported. An extensive testing campaign has been carried out at the CNR ITAE laboratory, with multiple aims. First, the performance has been evaluated in terms of both COP and Specific Cooling Power (SCP), under different boundary conditions, including both air conditioning and refrigeration applications. Attractive SCPs, up to 180 W/kg and 70 W/kg for air conditioning and refrigeration, respectively, were measured. Under the same conditions, COP between 0.17 and 0.08 were obtained. In addition, different management strategies, namely, heat recovery between adsorbers and re-allocation of phase durations, were evaluated to identify their influence on the system. Both strategies confirmed the possibility of increasing COP and SCP up to 40\% and 25\%, respectively. Moreover, a design analysis based on the experimental results has been carried out, to suggest possible improvements of the system. The obtained results demonstrated the possibility of employing a non-toxic refrigerant like ethanol reaching performance comparable with other harmful refrigerants like ammonia and methanol. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @inproceedings{MuchaMottokKraemer, author = {Mucha, Matthias and Mottok, J{\"u}rgen and Kr{\"a}mer, Stefan}, title = {Estimation of Worst Case Response Time Boundaries in Multi-Core Real-Time Systems}, series = {2017 International Conference on Applied Electronics (AE), 5-6 Sept. 2017, Pilsen}, booktitle = {2017 International Conference on Applied Electronics (AE), 5-6 Sept. 2017, Pilsen}, publisher = {IEEE}, isbn = {978-80-261-0641-8}, issn = {1803-7232}, doi = {10.23919/ae.2017.8053598}, pages = {1 -- 6}, abstract = {We address a novel probabilistic approach to estimate the Worst Case Response Time boundaries of tasks. Multi-core real-time systems process tasks in parallel on two or more cores. Tasks in our contribution may preempt other tasks, block tasks with semaphores to access global shared resources, or migrate to another core. The depicted task behavior is random. The shape of collected response times of a task within a processing time is multimodal. Extreme Value approaches need unimodal response time distributions to estimate the Worst Case Response Time of tasks. The new proposed method derives a set of three task set shapes from the source task set. It is used to minimize the uncertainty of random task behavior by maximizing the coverage of possible Worst Case Response Times. The case study evaluates the new proposed estimation method by the use of dynamically generated random tasks with varying task properties.}, language = {en} } @article{BelyaevaKramarenkoShamoninChamonine, author = {Belyaeva, Inna A. and Kramarenko, Elena Yu and Shamonin (Chamonine), Mikhail}, title = {Magnetodielectric effect in magnetoactive elastomers: Transient response and hysteresis}, series = {POLYMER}, volume = {127}, journal = {POLYMER}, publisher = {ELSEVIER}, doi = {10.1016/j.polymer.2017.08.056}, pages = {119 -- 128}, abstract = {Magnetodielectric properties of magnetoactive elastomers comprising micrometer-sized iron particles dispersed in compliant elastomer matrices are experimentally studied in stepwise time-varying dc magnetic fields. It is found that imposition of magnetic field significantly increases both the effective lossless permittivity of these composite materials as well as their effective conductivity. These magnetodielectric effects are more pronounced for larger concentrations of soft-magnetic filler particles and softer elastomer matrices. The largest observed relative change of the effective dielectric constant in the maximum magnetic field of 0.57 T is of the order of 1000\%. The largest observed absolute change of the loss tangent is approximately 0.8. The transient response of the magnetodielectric effect to a step magnetic-field excitation can be rather complex. It changes from a simple monotonic growth with time for small magnetic-field steps (<0.1 T) to a non-monotonic behavior with a significant rapidly appearing overshoot for large magnetic-field steps (>0.3 T). The settling time to the magnetic-field step excitation can reach roughly 1000 s and it depends on the applied magnetic field and sample composition. There is also significant hysteresis of the magnetodielectric effect on the externally applied magnetic field. These findings are attributed to the rearrangement of ferromagnetic filler particles in external magnetic fields. The results will be useful for understanding and predicting the transient behavior of magnetoactive elastomers in applications where the control magnetic field is time dependent. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{SorokinBelyaevaShamoninChamonineetal., author = {Sorokin, Vladislav V. and Belyaeva, Inna A. and Shamonin (Chamonine), Mikhail and Kramarenko, Elena Yu}, title = {Magnetorheological response of highly filled magnetoactive elastomers from perspective of mechanical energy density: Fractal aggregates above the nanometer scale?}, series = {Physical Review E}, volume = {95}, journal = {Physical Review E}, number = {6}, publisher = {Amer Physical Soc}, doi = {10.1103/PhysRevE.95.062501}, abstract = {The dynamic shear modulus of magnetoactive elastomers containing 70 and 80 mass \% of carbonyl iron microparticles is measured as a function of strain amplitude via dynamic torsion oscillations in various magnetic fields. The results are presented in terms of the mechanical energy density and considered in the framework of the conventional Kraus model. The form exponent of the Kraus model is further related to a physical model of Huber et al. [Huber et al., J. Phys.: Condens. Matter 8, 409 (1996)] that uses a realistic representation for the cluster network possessing fractal structure. Two mechanical loading regimes are identified. At small strain amplitudes the exponent beta of the Kraus model changes in an externally applied magnetic field due to rearrangement of ferromagnetic-filler particles, while at large strain amplitudes, the exponent beta seems to be independent of the magnetic field. The critical mechanical energy characterizing the transition between these two regimes grows with the increasing magnetic field. Similarities between agglomeration and deagglomeration of magnetic filler under simultaneously applied magnetic field and mechanical shear and the concept of jamming transition are discussed. It is proposed that the magnetic field should be considered as an additional parameter to the jamming phase diagram of rubbers filled with magnetic particles.}, language = {en} } @incollection{SternerBauerCrotoginoetal., author = {Sterner, Michael and Bauer, Franz and Crotogino, Fritz and Eckert, Fabian and von Olshausen, Christian and Teichmann, Daniel and Thema, Martin}, title = {Chemische Energiespeicher}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_8}, pages = {327 -- 493}, subject = {Energiespeicher}, language = {de} } @incollection{StadlerBauerBudtetal., author = {Stadler, Ingo and Bauer, Franz and Budt, Marcus and Heindl, Eduard and Wolf, Daniel}, title = {Mechanische Energiespeicher}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48893-5}, doi = {10.1007/978-3-662-48893-5_9}, pages = {495 -- 577}, language = {de} } @incollection{SternerBauer, author = {Sterner, Michael and Bauer, Franz}, title = {Definition und Klassifizierung von Energiespeichern}, series = {Energiespeicher - Bedarf, Technologien, Integration}, booktitle = {Energiespeicher - Bedarf, Technologien, Integration}, edition = {2. Auflage}, publisher = {Springer Vieweg}, address = {Berlin ; Heidelberg}, isbn = {978-3-662-48892-8}, doi = {10.1007/978-3-662-48893-5_2}, pages = {25 -- 49}, subject = {Energiespeicher}, language = {de} } @inproceedings{RauchBrueckl, author = {Rauch, Johannes and Br{\"u}ckl, Oliver}, title = {Analysis of the correlation behavior between local available information to the overall reactive power of a medium-voltage grid group}, series = {Applied Research Conference - ARC 2017, 7 July 2017 M{\"u}nchen}, booktitle = {Applied Research Conference - ARC 2017, 7 July 2017 M{\"u}nchen}, address = {M{\"u}nchen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-58712}, pages = {224 -- 230}, abstract = {The initiated energy transition leads to extensive changes in the supply of energy. The increasing use of renewable energy causes a shift of the produced power from centralized conventional power plants to decentralized energy plants. Because of this redistribution and the related change of load-flows, new challenges and problems for distribution system operators appear. This includes the integration of new loads and plants into the existing power grid and the guarantee of a high supply security and quality. It also includes strengthened requirements for the use and provision of reactive power. The project "SyNErgie" ("Systemoptimierendes Netz- und Energiemanagement f{\"u}r Verteilungsnetze der Zukunft") deals with the development of a new reactive power management, which gets embedded in grid planning and controlling processes. One focus of the project is on the integration of decentralized energy plants (DEPs) to the reactive power management. The aim is to develop a decentralized and self-sufficient reactive power control system, which only works with local available information (measures). Therefore is no necessity of a complex communication system to the grid control center. Self-controlled Q-controller in the DEPs get characteristic curves and control the reactive power sources with local measurements (e.g. current, voltage, effective power). This new reactive power control management aims for the reactive power compensation in order to increase the integration capacity of loads and plants in a grid [2]. In order to generate characteristic curves for DEPs, it is necessary to analyze the correlation behavior between the local available measurements at the DEPs and the overall-Q-behavior of the grid group at the transformer. In that regard, influencing quantities should be considered. The aim is to involve und evaluate all relevant influencing quantities in order to determine energy plants and certain operating points, in which the correlation behavior and the prediction for the overall-Q-behavior are sufficient. The next step is to develop a model that fits these correlation behaviors and generate characteristic curves. One method to generate characteristic curves for the Q-controllers is regression analysis. The developed Q-control-system with the characteristic curves will be tested, evaluated and optimized in a following field test in cooperation with distribution system operators.}, language = {de} } @book{RillSchaeffer, author = {Rill, Georg and Schaeffer, Thomas}, title = {Grundlagen und Methodik der Mehrk{\"o}rpersimulation}, edition = {3. Aufl.}, publisher = {Springer}, address = {Wiesbaden}, isbn = {978-3-658-16008-1}, doi = {10.1007/978-3-658-16009-8}, abstract = {Dieses Lehrbuch stellt die Methoden der Mehrk{\"o}rpersimulation anschaulich dar und erl{\"a}utert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer K{\"o}rper bilden dabei die Schwerpunkte. Konkrete Beispiele beinhalten die Eigendynamik eines Traktors mit Vorderachsfederung, das Hubschrauberrotorblatt sowie eine Pkw- Vorderachse. Die entsprechenden Matlab-Skripte und L{\"o}sungen zu den {\"U}bungsaufgaben k{\"o}nnen auf der Springer-Homepage beim Buch heruntergeladen werden. Neu aufgenommen wurden SparseMatrix Operationen sowie ein Beispiel zu einfach geschlossenen kinematischen Schleifen.}, language = {de} } @misc{OPUS4-6694, title = {Energieforschung}, edition = {Ausgabe 2016}, publisher = {OTH Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg / Regensburg Center of Energy and Resources (RCER)}, doi = {10.35096/othr/pub-6694}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-66948}, abstract = {Das Regensburg Center of Energy and Resources (RCER) b{\"u}ndelt seit 2012 die Aktivit{\"a}ten der Ostbayerischen Technischen Hochschule Regensburg (OTH Regensburg) und der regionalen Wirtschaftsunternehmen auf dem Strategiefeld „Energie und Ressourcen".}, language = {de} } @incollection{StrohmayerBrueckl, author = {Strohmayer, Bernhard and Br{\"u}ckl, Oliver}, title = {Systemvergleich von Netzausbauoptionen in Niederspannungsnetzen}, series = {3. OTTI-Konferenz : zuk{\"u}nftige Stromnetze f{\"u}r Erneuerbare Energien, Berlin, 26./27. Januar 2016}, booktitle = {3. OTTI-Konferenz : zuk{\"u}nftige Stromnetze f{\"u}r Erneuerbare Energien, Berlin, 26./27. Januar 2016}, address = {Regensburg}, organization = {Ostbayerisches Technologie-Transfer-Institut (OTTI)}, isbn = {978-3-943891-63-8}, pages = {256 -- 261}, abstract = {Die Einhaltung der Spannungsbandgrenzen im Niederspannungsnetz durch die dezentrale Emspeisung von Erzeugungsanlagen ist oft der Grund f{\"u}r Netzausbaumaßnahmen. Dem Netzbetreiber stehen mittlerweile viele Losungsmaßnahmen zur Behebung des Spannungsbandproblems zur Verf{\"u}gung Innovative Konzepte wie der regelbare Ortsnetztransformator (RONT) oder Blindleistungsregelung sind bereits serienreif und werden eingesetzt. Unklarheit herrscht oft noch dar{\"u}ber, welche Maßnahmen bzw Kombinationen langfristig wirtschaftlich g{\"u}nstig sind und sich hinsichtlich der Netzplanung als vorteilhaft erweisen. Ein Forschungsprojekt an der Ostbayerischen Technischen Hochschule Regensburg untersucht verschiedene L{\"o}sungsmaßnahmen systematisch, um sie wirtschaftlich, technisch und energetisch bewerten zu k{\"o}nnen. In 20 Netzen wird in diskreten Schritten die Integration von Erzeugungskapazit{\"a}t am Beispiel der PV simuliert. Der Zubau umfasst den Bereich von 0-100\% des m{\"o}glichen Dachfl{\"a}chenpotenzials. Nach jedem Zubauschritt wird die maximale Spannungsanhebung berechnet. Bei {\"U}berschreiten einer Spannungsanhebung in H{\"o}he der in [VDE, FNN Erzeugungsanlagen am Niederspannungsnetz, VDE-AR-N 4105:2011-08] verankerten drei Prozentpunkte, oder der Stromtragf{\"a}higkeitsgrenze eines Betriebsmittels erfolgt ein Netzausbau. Dabei werden die Optionen RONT, die Parallelverkabelung, drei Stufen des Einspeisemanagements (Spitzenkappung auf 85\%, 70\% und 55\%), die Blindleistungsregelung (cosφ(P)), der Zubau von zus{\"a}tzlichen Ortsnetzstationen und die Verwendung von Strangreglern untersucht. Je kleiner das Ortsnetz, desto st{\"a}rker bedingt sich die Kostenentwicklung durch die gew{\"a}hlte Prim{\"a}rmaßnahme. Klassischer Netzausbau ist in kleinen Netzen meist teurer als der Einsatz von RONT oder Strangreglern. In gr{\"o}ßeren Netzen k{\"o}nnen Parallelverkabelung oder zus{\"a}tzliche ONS zu g{\"u}nstigen Ausbaupfaden f{\"u}hren. Maßnahmen die anfangs nahezu keine Investition in Netzbetriebsmittel ben{\"o}tigen (Einspeisemanagement, Blindleistungsregelung) sind initial mit Abstand am g{\"u}nstigsten. Im Mittel g{\"u}nstiger als RONT sind anfangs auch Verkabelung und Strangregler, jedoch bei h{\"o}herer Ergebnisstreuung. Bereits nach f{\"u}nf Perioden liegen die mittleren Gegenwartswerte f{\"u}r starke Spitzenkappung, Blindleistungsregelung und zus{\"a}tzliche ONS h{\"a}ufig {\"u}ber der Maßnahme RONT. Die geringste Kostenstreuung tritt beim Einsatz von RONT auf. Mittel- und langfristig liegen die Mediane fast aller Prim{\"a}rmaßnahmen {\"u}ber den wahrscheinlich auftretenden Kosten f{\"u}r Strangregler und RONT. Bei Erschließung von zus{\"a}tzlichen 25\% des theoretisch maximalen Potenzials nach Erreichen der NAK betragen die Kosten bei RONT-Einsatz ca. 125/kWp. Parallelverkabelung verursacht rd. 45, Blindleistungsregelung rd. 55 €/kWp Mehrkosten. Bei 50\% des Ausbaupotenzials f{\"u}hren Parallelverkabelung und Blindleistungsregelung mit im Mittel 50 bzw. 75 €/kWp sogar zu noch h{\"o}heren Mehrkosten. F{\"u}r 20 GW PV-Leistung in der Niederspannung bedeutet dies {\"u}ber 1 Mrd. Zusatzkosten. RONT und Strangregler erweisen sich zudem kostenrobust gegen{\"u}ber unerwartet ausbleibendem Kapazit{\"a}tszubau. Analysen dazu und Ergebnisse f{\"u}r andere Zinss{\"a}tze und Zeitskalen befinden sich in [INA, Informationsportal: Regelbare Ortsnetztransformatoren, 2015. http://ront.info].}, language = {de} }