TY - CHAP A1 - Lalo, Erjola A1 - Deubzer, Michael A1 - Schmidhuber, Stefan A1 - Oklapi, Erna A1 - Mottok, Jürgen T1 - Task Priority Optimization in Real-Time Multi-Core Embedded Systems T2 - 4. Landshuter Symposium Mikrosystemtechnik, Mikrosystemtechnik als Schlüsseltechnologie der Systemintegration, Tagungsband zum Symposium 12./13. März 2014, Hochschule Landshut N2 - The shift from single-core to multi-core processors in real-time embedded systems leads to communication based effects on timing such as inter-core communication delays and blocking times. Moreover, the complexity of the scheduling problem increases when multi-core processors are used. In priority-based-scheduling, a fixed priority assignment is used in order to enable predictable behavior of the system. Predictability means that the system has to be analyzable which allows the detection of problems coming from scheduling decisions. For fixed priority scheduling in multi-core real-time embedded systems, a proper task priority assignment has to be done in a way that the system has minimal effects on timing. In this paper, we present an approach for finding near-optimal solutions for task priority assignment and the preemption/cooperation problem. A genetic algorithm is hereby used to create priority assignment solutions. A timing simulator is used for evaluation of each solution regarding real-time properties, memory consumption and communication overhead. In a case study we demonstrate that the proposed approach performs better than well known and single-core optimal heuristics for relatively complex systems. Y1 - 2014 SN - 978-3-9812696-5-9 SP - 96 EP - 109 CY - Landshut ER - TY - CHAP A1 - Altmann, Andreas A1 - Birkner, Wolfgang A1 - Häckl, Franz-Xaver A1 - Hanner, Christopher A1 - Liebhart, Peter A1 - Metschl, Samuel A1 - Weck, Florian A1 - Farmbauer, Michael A1 - Heiß, Manfred A1 - Cuno, H.-H. A1 - Fuhrmann, Thomas A1 - Mandl, Roland A1 - Mottok, Jürgen A1 - Niemetz, Michael T1 - Payload development and launch of a stratosphere balloon mission T2 - IEEE Global Engineering Education Conference (EDUCON 2014), 3-5 April 2014, Istanbul, Turkey N2 - During a student project a stratosphere balloon was developed and launched. This project included the definition of the balloon parameters and the scientific instruments for performing atmospheric measurements, the development of all mechanical and electronic parts, the administration of the project as well as the management tasks related to the balloon launch. The main challenge for the students was the high complexity of the project due to tasks involving many different knowledge domains and the long project duration from the initial definition to the launch. Y1 - 2014 U6 - https://doi.org/10.1109/EDUCON.2014.6826065 ER - TY - JOUR A1 - Raab, Peter A1 - Krämer, Stefan A1 - Mottok, Jürgen A1 - Vavricka, Vlastimil T1 - Isomorphism between Linear Codes and Arithmetic Codes for Safe Data Processing in Embedded Software Systems JF - Computing and Informatics (CAI) N2 - We present a transformation rule to convert linear codes into arithmetic codes. Linear codes are usually used for error detection and correction in broadcast and storage systems. In contrast, arithmetic codes are very suitable for protection of software processing in computer systems. This paper shows how to transform linear codes protecting the data stored in a computer system into arithmetic codes safeguarding the operations built on this data. Combination of the advantages of both coding mechanisms will increase the error detection capability in safety critical applications for embedded systems by detection and correction of arbitrary hardware faults. Y1 - 2014 UR - https://pdfs.semanticscholar.org/eb7c/f626eb4dcf33bb9c615d477099188eadc76b.pdf?_ga=2.23977850.1374482597.1614464499-73487869.1612391519 VL - 33 SP - 721 EP - 734 ER - TY - CHAP A1 - Krämer, Stefan A1 - Raab, Peter A1 - Mottok, Jürgen A1 - Racek, Stanislav T1 - Comparison of Enhanced Markov Models and Discrete Event Simulation T2 - 17th Euromicro Conference on Digital System Design (DSD), 27-29 August 2014, Verona, Italy N2 - In this paper we present simulation and model based approaches for evaluating and validating the temporal and safety relevant properties of software intensive safety-critical real-time embedded systems. A high level reliability model of a safe task execution is described by a continuous-time Markov process, enhanced by the modeling of execution times. It is shown that the behavior - regarding real-time and safety metrics - of this theoretical model can be transferred into an abstract system timing model, which then can be analyzed by a discrete event simulation approach. The verification of the discrete event simulation by Markov models offers the possibility of a holistic approach for reliability analysis combined with schedulability analysis of complex safety-critical multicore real-time systems by the discrete event simulation. Y1 - 2014 U6 - https://doi.org/10.1109/DSD.2014.42 SP - 591 EP - 598 ER - TY - CHAP A1 - Mottok, Jürgen A1 - Scharfenberg, Georg T1 - Forschendes Lernen im Masterstudiengang Applied Research in Engineering Sciences T2 - 4th Applied Research Conference, 5th July 2014, Ingolstadt Y1 - 2014 SN - 978-3-8440-2875-1 SP - 55 EP - 61 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Scharfenberg, Georg A1 - Mottok, Jürgen T1 - Forschungsmaster entwickelt sich zum Wirtschaftsfaktor in Bayern T2 - 4th Applied Research Conference, 5th July 2014, Ingolstadt Y1 - 2014 SN - 978-3-8440-2875-1 SP - 55 EP - 61 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Gschossmann, Andreas A1 - Jobst, Simon A1 - Mottok, Jürgen A1 - Bierl, Rudolf T1 - A Measure of Confidence of Artificial Neural Network Classifiers T2 - ARCS Workshop 2019; 32nd International Conference on Architecture of Computing Systems, 20-21 May 2019, Copenhagen, Denmark N2 - Confidence in results of an Artificial Neural Networks (ANNs) is increased by preferring to reject data, that is not trustful, instead of risking a misclassification. For this purpose a model is proposed that is able to recognize data, which differs significantly from the training data, during inference. The proposed model observes all activations of the hidden layers, as well as input and output layers of an ANN in a grey-box view. To make ANNs more robust in safety critical applications, this model can be used to reject flawed data, that is suspected to decrease the accuracy of the model. If this information is logged during inference, it can be used to improve the model, by training it specifically with the missing information. An experiment on the MNIST dataset is conducted and its results are discussed. Y1 - 2019 UR - https://ieeexplore.ieee.org/document/8836211 SP - 153 EP - 157 PB - VDE-Verlag CY - Berlin ER - TY - CHAP A1 - Schmidhuber, Stefan A1 - Deubzer, Michael A1 - Mader, Ralph A1 - Niemetz, Michael A1 - Mottok, Jürgen T1 - Towards the Derivation of Guidelines for the Deployment of Real-Time Tasks on a Multicore Processor T2 - 4th International Symposium on Model-Based Safety and Assessment (IMBSA 2014), Munich, Germany, October 27-29, 2014, Proceedings N2 - The deployment of automotive software on a multicore processor includes the task of mapping executables to cores. Given the number of possible solutions, integrators have to solve a complex problem. Considering multiple, often conflicting goals like minimizing task response times and memory consumption, complexity further increased with the advent of multicore processors. We present a model-based approach for deriving design rules supporting integrators with statically mapping tasks to a multicore ECU. First, an evolutionary algorithm is used to sample the design space. For each sample, a model-based analysis is performed, resulting in the required fitness values according to the system metric objectives. Finally, subsets of the sample population are used to derive deployment guidelines by evaluating similarities between highly ranked solutions. This reduces the number of solutions to be considered by the integrators by orders of magnitude. In a case-study, we demonstrate the developed approach on an artificial automotive engine management system. KW - Real-time systems KW - embedded multicore systems KW - runnable partitioning KW - task-to-core mapping KW - software integration KW - design space exploration KW - evolutionary algorithm Y1 - 2014 SN - 978-3-319-12213-7 U6 - https://doi.org/10.1007/978-3-319-12214-4_12 SP - 152 EP - 165 PB - Springer CY - Munich ER - TY - CHAP A1 - Krämer, Stefan A1 - Raab, Peter A1 - Mottok, Jürgen A1 - Racek, Stanislav T1 - Comparison of Enhanced Markov Models and Discrete Event Simulation – for evaluation of probabilistic Faults in safety-critical real-time task sets T2 - Proceedings of EUROMICRO DSD 2014 - 17th Euromicro Conference on Digital System Design N2 - In this paper we present simulation and model based approaches for evaluating and validating the temporal and safety relevant properties of software intensive safety-critical real-time embedded systems. A high level reliability model of a safe task execution is described by a continuous-time Markov process, enhanced by the modeling of execution times. It is shown that the behavior - regarding real-time and safety metrics - of this theoretical model can be transferred into an abstract system timing model, which then can be analyzed by a discrete event simulation approach. The verification of the discrete event simulation by Markov models offers the possibility of a holistic approach for reliability analysis combined with schedulability analysis of complex safety-critical multicore real-time systems by the discrete event simulation. KW - Model KW - Stochastic simulation KW - reliability analysis KW - safe software processing KW - real-time operating system KW - multicore scheduling KW - discrete event simulation KW - fault injection Y1 - 2014 U6 - https://doi.org/10.1109/DSD.2014.42 SP - 591 EP - 598 ER - TY - CHAP A1 - Alfranseder, Martin A1 - Deubzer, Michael A1 - Justus, Benjamin A1 - Mottok, Jürgen A1 - Siemers, Christian T1 - An Efficient Spin-Lock Based Multi-Core Resource Sharing Protocol T2 - 33rd IEEE International Performance, Computing, and Communications Conference (IPCCC), Austin (TX), USA, 5-7 December 2014 N2 - We present in this paper a new lock-based resource sharing protocol PWLP (Preemptable Waiting Locking Protocol) for embedded multi-core processors. It is based on the busy-wait model and works with non-preemptive critical sections while task may be preempted by tasks with a higher priority when waiting for resources. Our protocol can be applied in partitioned as well as global scheduling scenarios, in which task-fix, job-fix or dynamically assigned priorities may be used. Furthermore, the PWLP permits nested requests to shared resources. Finally, we present a case study based on event-based simulations in which the FMLP (Flexible Multiprocessor Locking Protocol) and the proposed PWLP are compared. Y1 - 2014 U6 - https://doi.org/10.1109/PCCC.2014.7017090 ER -