05 Fakultät Informatik, Elektrotechnik und Informationstechnik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6

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Institute: search.filters.UBSInstitut.Institut für Parallele und Verteilte SystemeInstitute: search.filters.UBSInstitut.Stuttgarter Zentrum für Simulationswissenschaften (SC SimTech)

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    A deep learning approach for large-scale groundwater heat pump temperature prediction
    (2022) Scheurer, Stefania
    Heating and cooling buildings is one of the most energy-intensive aspects of modern life. To minimize the impact on global warming and decelerate climate change, more efficient and carbon emission-mitigating technologies such as openloop groundwater heat pumps (GWHP) for heating and cooling buildings are being used and quickly adopted. Nowadays, in order to guarantee their optimal use and prevent negative interactions, city planners need to optimize their placement in the urban landscape. This optimization process requires fast models that simulate the effect of a GWHP on the groundwater temperature. Considering a large domain with multiple GWHPs, this work introduces a framework for the groundwater temperature prediction. While using a learned local surrogate model, a convolutional neural network, to predict the local temperature field around every single GWHP, a physics-informed neural network (PINN) is employed afterwards to correct the global initial solution of stitched together local predictions. As the violations of the physical laws described by the underlying partial differential equation(s) are spatially unevenly distributed, two different methods for drawing sampling points, on the basis of which the training of the PINN to correct the global initial solution takes place, are investigated and compared. This work shows that it is possible for a PINN to correct the global initial solution of stitched together local predictions in a domain with multiple GWHPs. However, there are still opportunities to improve the quality and decrease the computational time of the presented framework. The best method for drawing sampling points depends on the scenario and the placement of the GWHPs. Thus, no general statement can be made, which of the two methods is more suitable. This work provides a good basis for further investigation of the presented framework.
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    Comparison of different Hyperparameter-Tuners for Support Vector Machines : an analysis using Parallel Least-Squares SVM Library on GPU
    (2024) Dzubba, Yannick Marian
    Working with large datasets requires sophisticated tools. One such tool developed for classification is the Support Vector Machine (SVM). As with any ML algorithm, the user has to set several different Hyper Parameter (HP) to run a SVM. Finding the optimal choice of HPs is important for model performance and it is highly dependent on the dataset. Given the number of different HPs, a search space might be massive, so optimization methods have been developed, to automate this search. This work aims to compare three popular choices: The Grid Search, the Random Search and Bayesian Model Search. They are compared in different metrics, such as performance, runtime and energy. Optuna [ASY+19] was used as optimizer backend, it implements all three optimizer types, it implements Tree-Parzan Estimator (TPE) as Bayesian Search algorithm. It was connected to Parallel Least-Squares Support Vector Machine (PLSSVM) [VCBP22] as SVM implementation. PLSSVM can efficiently exploit parallel compute cores. The optimizers have been tested on a selection of different search spaces and datasets with PLSSVM running on Graphic Processing Unit (GPU).
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    Research data management in simulation science : infrastructure, tools, and applications
    (2024) Flemisch, Bernd; Hermann, Sibylle; Herschel, Melanie; Pflüger, Dirk; Pleiss, Jürgen; Range, Jan; Roy, Sarbani; Takamoto, Makoto; Uekermann, Benjamin
    Research Data Management (RDM) has gained significant traction in recent years, being essential to allowing research data to be, e.g., findable, accessible, interoperable, and reproducible (FAIR), thereby fostering collaboration or accelerating scientific findings. We present solutions for RDM developed within the DFG-Funded Cluster of Excellence EXC2075 Data-Integrated Simulation Science (SimTech). After an introduction to the scientific context and challenges faced by simulation scientists, we outline the general data management infrastructure and present tools that address these challenges. Exemplary domain applications demonstrate the use and benefits of the proposed data management software solutions. These are complemented by additional measures for enablement and dissemination to foster the adoption of these techniques.
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    Real-time visualized and GPU-accelerated lattice Boltzmann simulations
    (2025) Graf, Marcel
    In a preceding project, four lattice Boltzmann algorithms were implemented on the CPU using HPX. Building up on this project, the goal of this work is to implement the two most suitable algorithms on the GPU together with a framework permitting real-time visualization. In the propaedeuticum, fundamental concepts of GPU programming are elaborated, and based on the insights gained, the aptitude of the four algorithms from the project for a portation to the GPU is investigated. The two-lattice and the swap algorithm were identified as the most promising candidates. The visualization framework was designed using the Dear ImGui and ImPlot APIs. In the bachelor thesis, the swap algorithm and multiple variants of the two-lattice algorithm were realized using AdaptiveCpp, which is one of two major implementations of the SYCL standard. Kármán vortex streets were chosen as a scenario demonstrating the capabilities of the proposed simulations. Since all algorithms update the lattice faster than the frontend can accept new frames, all of them are suitable for fulfilling the objective under the limitations imposed by the visualization framework. Similarly to the project, a simple and mostly runtime-coordinated two-lattice variant was recognized as the most convenient and, at the same time, very competitive implementation. Out of the data layouts proposed by Mattila et al., the bundle layout is well suited for devices with small caches, while the stream layout uses the memory bandwidth more efficiently. The optimal work group size and subdomain shape also depend on the targeted hardware.