TY - JOUR A1 - Broser, Christian A1 - Falter, Thomas A1 - Ławrowski, Robert Damian A1 - Altenbuchner, Amelie A1 - Vögele, Daniel A1 - Koss, Claus A1 - Schlamp, Matthias A1 - Dunnweber, Jan A1 - Steffens, Oliver A1 - Heckner, Markus A1 - Jaritz, Sabine A1 - Schiegl, Thomas A1 - Corsten, Sabine A1 - Lauer, Norina A1 - Guertler, Katherine A1 - Koenig, Eric A1 - Haug, Sonja A1 - Huber, Dominik A1 - Birkenmaier, Clemens A1 - Krenkel, Lars A1 - Wagner, Thomas A1 - Justus, Xenia A1 - Saßmannshausen, Sean Patrick A1 - Kleine, Nadine A1 - Weber, Karsten A1 - Braun, Carina N. A1 - Giacoppo, Giuliano A1 - Heinrich, Michael A1 - Just, Tobias A1 - Schreck, Thomas A1 - Schnabl, Andreas A1 - Gilmore, Amador Téran A1 - Roeslin, Samuel A1 - Schmid, Sandra A1 - Wellnitz, Felix A1 - Malz, Sebastian A1 - Maurial, Andreas A1 - Hauser, Florian A1 - Mottok, Jürgen A1 - Klettke, Meike A1 - Scherzinger, Stefanie A1 - Störl, Uta A1 - Heckner, Markus A1 - Bazo, Alexander A1 - Wolff, Christian A1 - Kopper, Andreas A1 - Westner, Markus A1 - Pongratz, Christian A1 - Ehrlich, Ingo A1 - Briem, Ulrich A1 - Hederer, Sebastian A1 - Wagner, Marcus A1 - Schillinger, Moritz A1 - Görlach, Julien A1 - Hierl, Stefan A1 - Siegl, Marco A1 - Langer, Christoph A1 - Hausladen, Matthias A1 - Schreiner, Rupert A1 - Haslbeck, Matthias A1 - Kreuzer, Reinhard A1 - Brückl, Oliver A1 - Dawoud, Belal A1 - Rabl, Hans-Peter A1 - Gamisch, Bernd A1 - Schmidt, Ottfried A1 - Heberl, Michael A1 - Gänsbauer, Bianca A1 - Bick, Werner A1 - Ellermeier, Andreas A1 - Monkman, Gareth J. A1 - Prem, Nina A1 - Sindersberger, Dirk A1 - Tschurtschenthaler, Karl A1 - Aurbach, Maximilian A1 - Dendorfer, Sebastian A1 - Betz, Michael A. A1 - Szecsey, Tamara A1 - Mauerer, Wolfgang A1 - Murr, Florian ED - Baier, Wolfgang T1 - Forschung 2018 T3 - Forschungsberichte der OTH Regensburg - 2018 KW - Forschung KW - Forschungsbericht Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-13826 SN - 978-3-9818209-5-9 CY - Regensburg ER - TY - CHAP A1 - Fritz, Florian A1 - Schmid, Michael A1 - Mottok, Jürgen ED - Brinkmann, André T1 - Accelerating Real-Time Applications with Predictable Work-Stealing T2 - Architecture of computing systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings N2 - Modern compute architectures often consist of multiple CPU cores to achieve their performance, as physical properties put a limit on the execution speed of a single processor. This trend is also visible in the embedded and real-time domain, where programmers are forced to parallelize their software to keep deadlines. Additionally, embedded systems rely increasingly on modular applications, that can easily be adapted to different system loads and hardware configurations. To parallelize applications under these dynamic conditions, often dispatching frameworks like Threading Building Blocks (TBB) are used in the desktop and server segment. More recently, Embedded Multicore Building Blocks (EMB2) was developed as a task-based programming solution designed with the constraints of embedded systems in mind. In this paper, we discuss how task-based programming fits such systems by analyzing scheduler implementation variants, with a focus on classic work-stealing and the libraries TBB and EMB2. Based on the state of the art we introduce a novel resource-trading concept that allows static memory allocation in a work-stealing runtime holding strict space and time bounds. We conduct benchmarks between an early prototype of the concept, TBB and EMB2, showing that resource-trading does not introduce additional runtime overheads, while unfortunately also not improving on execution time variances. KW - Real-time KW - Parallel programming KW - Work-stealing Y1 - 2020 U6 - https://doi.org/10.1007/978-3-030-52794-5_18 SP - 241 EP - 255 ER - TY - CHAP A1 - Schmid, Michael A1 - Fritz, Florian A1 - Mottok, Jürgen T1 - Parallel Programming in Real-Time Systems T2 - Architecture of computing systems - ARCS 2019, 32nd international conference, Copenhagen, Denmark, May 20-21, 2019, proceedings N2 - The enormous amounts of data modern real-time systems have to process lead to expensive, long-lasting calculations. In order to manage those computations in a timely manner, parallel task models have gained a lot of popularity lately. However, parallel programming can be very cumbersome and verbose. Other computationally intensive sectors have dealt with parallel computing for decades and have accumulated their experience in the development of parallel frameworks. Examples of well known parallel runtime systems are OpenMP, Intel Threading Building Blocks (TBB) and Microsoft Parallel Pattern Library (PPL). These runtime systems allow developers to enhance parallelism in their applications in a straightforward fashion. However, those parallel frameworks and the patternbased interfaces they provide might not be easily applicable in real-time systems. In this paper, we investigate the use of parallel programming frameworks in time-critical systems. On that account, we discuss considerations for the design of real-time applications that make use of such parallel runtime systems. Furthermore, we evaluate three library-based frameworks from different computing sectors, namely Intel Threading Building Blocks, Embedded Multicore Building Blocks (EMBB) and High Performance ParalleX (HPX), by conducting benchmarks of various parallel algorithms on an embedded multicore architecture. Y1 - 2019 UR - https://ieeexplore.ieee.org/abstract/document/8836206 PB - VDE-Verlag CY - Berlin ER - TY - JOUR A1 - Schmid, Michael A1 - Fritz, Florian A1 - Mottok, Jürgen T1 - Fine-Grained Parallel Applications in Real-Time Multiprocessor Systems JF - Journal of Systems Architecture N2 - Lately, parallel task models have received much attention in the development of real-time multiprocessor systems, as they allow highly compute-intensive tasks to have shorter deadlines which is very much required in modern reactive systems. However, missing modularity and portability can make parallel programming a cumbersome endeavor. As a consequence, compute-intensive sectors in the desktop and server segment have relied on parallelism frameworks such as Intel Threading Building Blocks, Cilk and OpenMP. These parallelism frameworks, however, are optimized for decent average case performance and consequently, do not meet the strict requirements imposed by real-time systems. In this paper, we present a proof-of-concept parallelism framework which was implemented in particular for soft real-time systems and having tight timing and safety requirements of such critical systems in mind. The proposed runtime system implements static memory allocation in a work-stealing environment that conforms to the strict space and tight probabilistic time bounds of work-stealing schedulers. Furthermore, we evaluate the performance of this framework by conducting multiprogrammed benchmarks on a real-time embedded multicore architecture. KW - Real-time KW - Work-stealing KW - Thread pool KW - Task model KW - Parallel programming Y1 - 2021 U6 - https://doi.org/10.1016/j.sysarc.2022.102393 VL - 124 PB - Elsevier ER - TY - JOUR A1 - Schmid, Michael A1 - Fritz, Florian A1 - Mottok, Jürgen T1 - Fine-grained parallelism framework with predictable work-stealing for real-time multiprocessor systems JF - Journal of Systems Architecture N2 - Lately, parallel task models have received much attention in the development of real-time multiprocessor systems, as they allow highly compute-intensive tasks to have shorter deadlines which is very much required in modern reactive systems. However, missing modularity and portability can make parallel programming a cumbersome endeavor. As a consequence, compute-intensive sectors in the desktop and server segment have relied on parallelism frameworks such as Intel Threading Building Blocks, Cilk and OpenMP. These parallelism frameworks, however, are optimized for decent average case performance and consequently, do not meet the strict requirements imposed by real-time systems. In this paper, we present a proof-of-concept parallelism framework which was implemented in particular for soft real-time systems and having tight timing and safety requirements of such critical systems in mind. The proposed runtime system implements static memory allocation in a work-stealing environment that conforms to the strict space and tight probabilistic time bounds of work-stealing schedulers. Furthermore, we evaluate the performance of this framework by conducting multiprogrammed benchmarks on a real-time embedded multicore architecture. Y1 - 2022 U6 - https://doi.org/10.1016/j.sysarc.2022.102393 N1 - Corrigendum: https://www.sciencedirect.com/science/article/pii/S1383762123000528?via%3Dihub VL - 124 IS - March PB - Elsevier ER - TY - CHAP A1 - Schmid, Florian A1 - Wild, Tobias A1 - Schneidewind, Jan A1 - Vogl, Tobias A1 - Schuhegger, Lukas A1 - Galka, Stefan T1 - Simulation Based Approach for Reconfiguration and Ramp up Scenario Analysis in Factory Planning T2 - Proceedings of the 2022 Winter Simulation Conference (WSG), 11-14 Dec. 2022, Singapore N2 - Structural changes in production entail a potential economic risk for manufacturing companies. It is necessary to identify a suitable strategy for the reconfiguration process and to continue to meet the demand during the change in the factory structure and ramp-up phase. A simulation offers the possibility to analyze different ramp-up scenarios for the factory structure and to select a suitable concept for the reconfiguration process. A discrete event simulation approach is presented that can be used to evaluate variants of structural changes and serves as a basis for deciding on a reconfiguration strategy. This approach is demonstrated using a specific production step of a plant producing hydrogen electrolyzers, the results and generalized conclusions are discussed. KW - Simulation KW - Production KW - Ramp up Y1 - 2022 SN - 978-1-6654-7661-4 U6 - https://doi.org/10.1109/WSC57314.2022.10015310 SP - 2842 EP - 2852 PB - IEEE ER - TY - CHAP A1 - Galka, Stefan A1 - Schmid, Florian ED - Schlund, Sebastian ED - Ansari, Fazel T1 - Initialization of Simulation-Based Digital Twins for Internal Transport Systems T2 - IFAC-PapersOnLine N2 - To support operational decisions using simulation-based digital twins, it is crucial to synchronize the simulation model quickly and accurately with the load state in the real system. This minimizes the typical transient behavior of material flow simulations to a short period of time. This paper presents a concept for initializing a simulation model using the example of a distribution center that uses SAP EWM as a warehouse management system. As part of a study, the influence of the presented initialization concept on the simulation models’ transient behavior is investigated. The simulation model used as a reference is in an ‘empty’ load state at the beginning of the simulation. The study results indicate that the proposed approach can significantly shorten the transient behavior. KW - Discrete event simulation KW - Digital Twins KW - Logistic KW - Modell Initialization Y1 - 2024 U6 - https://doi.org/10.1016/j.ifacol.2024.09.127 SN - 2405-8963 VL - 58 IS - 19 SP - 1084 EP - 1089 CY - Wien ER - TY - CHAP A1 - Schmid, Florian A1 - Galka, Stefan A1 - Marinkovic, Minja A1 - Meißner, Sebastian ED - Bergmann, Sören ED - Feldkamp, Niclas ED - Souren, Rainer ED - Straßburger, Steffen T1 - Simulationsbasierte Untersuchung von Abstraktionsgraden im Kontext Digitaler Zwillinge für innerbetriebliche Transportsysteme T2 - Tagungsband 20. ASIM-Fachtagung Simulation in Produktion und Logistik, Ilmenau, 13. – 15. September 2023 N2 - Current challenges in the planning and control of internal logistics systems are based on permanent changes in the requirements on the system, e.g., due to fluctuating order numbers or changes in their structure. For the representation and planning of in-house logistics processes, digital twins offer the possibility to verify different operational decisions such as predictive workforce scheduling. In this context, the quality of the results and their in-time presentation plays a decisive role. However, both target criteria are influenced by the detail-level of the digital representation. Based on a case study, this paper investigates the influence of the level of detail on the simulation runtime and result divergence to provide an evaluation for detail levels in the modelling of intralogistic transport systems. T2 - Simulation-based Analysis of Abstraction Degrees in the Context of Digital Twins for Intralogistics Transport Systems Y1 - 2023 SN - 978-3-86360-276-5 U6 - https://doi.org/10.22032/DBT.57794 SP - 135 EP - 144 PB - Universitätsverlag Ilmenau CY - Ilmenau ER - TY - CHAP A1 - Galka, Stefan A1 - Schmid, Florian A1 - Grasser, Dominik A1 - Hohm, Jonathan A1 - Stauber, Stephan A1 - Meißner, Sebastian T1 - Integration eines SAP-Transportleitsystem in eine Simulationsumgebung zur Unterstützung von Entscheidungen im operativen Betrieb T2 - Tagungsband 20. ASIM-Fachtagung Simulation in Produktion und Logistik, Ilmenau, 13. – 15. September 2023 N2 - Digital twins enable the digital representation of physical systems and provide comprehensive modelling and analysis capabilities. An online data exchange between the Digital twin and SAP is feasible, through integration of a transport control systems (SAP) via RESTful API. This interface allows decision making in resource allocation and furthermore the adaptation of the digital model if the real system changes. Despite the associated challenges in terms of data synchronisation, the integration has benefits such as a reduction in modelling effort and an increase in the lifetime of the digital twin. In the context of this work, the design of the interface between the simulation software and a SAP transport control system via RESTful API is described. Y1 - 2023 SN - 978-3-86360-276-5 U6 - https://doi.org/10.22032/DBT.57813 SP - 281 EP - 291 PB - Universitätsverlag Ilmenau CY - ILmenau ER -