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Verburg, Corné (author)This thesis addresses the challenge of segmenting ultra-high-resolution images. Limitations of current approaches to segment these are that either detailed spatial contextual information is lost or many redundant computations are necessary. To overcome these issues, we propose a novel approach combining the U-Net architecture with domain...master thesis 2024
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Balzani, Daniel (author), Heinlein, A. (author), Klawonn, Axel (author), Knepper, Jascha (author), Nurani Ramesh, Sharan (author), Rheinbach, Oliver (author), Saßmannshausen, Lea (author), Uhlmann, Klemens (author)A computational framework is presented to numerically simulate the effects of antihypertensive drugs, in particular calcium channel blockers, on the mechanical response of arterial walls. A stretch-dependent smooth muscle model by Uhlmann and Balzani is modified to describe the interaction of pharmacological drugs and the inhibition of smooth...journal article 2024
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Kuai, H. (author), Civera, M. (author), Coletta, G. (author), Chiaia, B. (author), Surace, C. (author)In structural engineering, offshore structures are undoubtedly among the most exposed to the effects of harsh environmental conditions. The external conditions of these semi-immersed systems involve complex combinations of wave and wind loads. The operating conditions are also unique because oil production platforms are subjected to repeated...journal article 2024
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Heinlein, A. (author), Rheinbach, Oliver (author), Röver, Friederike (author)Multilevel extensions of overlapping Schwarz domain decomposition preconditioners of Generalized Dryja-Smith-Widlund (GDSW) type are considered in this paper. The original GDSW preconditioner is a two-level overlapping Schwarz domain decomposition preconditioner, which can be constructed algebraically from the fully assembled stiffness matrix...journal article 2023
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Jain, V. (author), Palha, A. (author), Gerritsma, M.I. (author)In this work we use algebraic dual spaces with a domain decomposition method to solve the Darcy equations. We define the broken Sobolev spaces and their finite dimensional counterparts. A global trace space is defined that connects the solution between the broken spaces. Use of algebraic dual spaces results in a sparse, metric-free...journal article 2023
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Machine Learning Based local Reduced Order Modeling for the prediction of Unsteady Aerodynamic LoadsCatalani, Giovanni (author)Advancements in aircraft performance require increasingly complex design processes and tools. Simulating the unsteady non-linear aerodynamic interaction between a maneuvering aircraft and the surrounding flowfield poses serious challenges. High-Fidelity Computational Fluid Dynamics (CFD) methods, based on the numerical solution of the Navier...master thesis 2022
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Sieburgh, Erik (author)Wave phenomena play an important role in many different applications such as MRI scans, seismology and acoustics [41, 49, 47]. At the core of such applications lies the Helmholtz equation, which represents the time-independent version of the wave equation. Simulating a Helmholtz problem numerically with accurate numerical solutions for large...master thesis 2022
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Benschop, Michiel (author)Due to increasingly efficient engineering of the last decades, the design process for civil structures is heading in the direction of optimal solutions. Among other things, the reduction in self-weight enhances the susceptibility to dynamic loads. As the process for the determination of realistic modal parameters from a digital model often...master thesis 2022
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Breunissen, Rens (author)Numerical methods for solving problems with a large contrast in the coefficients are investigated in this report. These types of problems typically appear in basin modeling. Specifically, the deflation and restricted additive Schwarz (RAS) methods are compared for their effectiveness in solving this type of problem in combination with the...master thesis 2022
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Heinlein, A. (author), Rheinbach, Oliver (author), Röver, Friederike (author)The parallel performance of the three-level fast and robust overlapping Schwarz (FROSch) preconditioners is investigated for linear elasticity. The FROSch framework is part of the Trilinos software library and contains a parallel implementation of different preconditioners with energy minimizing coarse spaces of generalized Dryja--Smith--Widlund...journal article 2022
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Heinlein, A. (author), Klawonn, Axel (author), Lanser, Martin (author)In this article, different nonlinear domain decomposition methods are applied to nonlinear problems with highly heterogeneous coefficient functions with jumps. In order to obtain a robust solver with respect to nonlinear as well as linear convergence, adaptive coarse spaces are employed. First, as an example for a nonlinearly left...journal article 2022
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Heinlein, A. (author), Perego, Mauro (author), Rajamanickam, Sivasankaran (author)Numerical simulations of Greenland and Antarctic ice sheets involve the solution of large-scale highly nonlinear systems of equations on complex shallow geometries. This work is concerned with the construction of Schwarz preconditioners for the solution of the associated tangent problems, which are challenging for solvers mainly because of...journal article 2022
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Heinlein, A. (author), Klawonn, Axel (author), Knepper, Jascha (author), Rheinbach, Oliver (author), Widlund, Olof B. (author)A new reduced-dimension adaptive generalized Dryja-Smith-Widlund (GDSW) overlapping Schwarz method for linear second-order elliptic problems in three dimensions is introduced. It is robust with respect to large contrasts of the coefficients of the partial differential equations. The condition number bound of the new method is shown to be...journal article 2022
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Mororó, L. A. T. (author), van der Meer, F.P. (author)The thick level set (TLS) method has been proposed as a nonlocal damage model for the modeling of failure in solids being able to deal with crack initiation, branching, and merging. The nonlocality of the TLS is achieved by introducing a characteristic length into the problem. This way, the TLS does not suffer from spurious localization in the...journal article 2021
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Zhang, Y. (author), Fisser, Joël (author), Gerritsma, M.I. (author)We introduce a domain decomposition structure-preserving method based on a hybrid mimetic spectral element method for three-dimensional linear elasticity problems in curvilinear conforming structured meshes. The method is an equilibrium method which satisfies pointwise equilibrium of forces. The domain decomposition is established through...journal article 2021
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Xiao, C. (author), Tian, Leng (author)This paper introduces an efficient surrogate model with the aim of accelerating joint estimation of subsurface geological properties and relative permeability parameters for high-dimensional inversion problems. We fully replace the high-fidelity model with a set of subdomain linear models through integrating model linearization with smooth...journal article 2020
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de Bruijn, Janno (author)In the Netherlands there are many bridges that crosses waterways, which are key nodes in the transportation system. The safety and integrity of these bridges is nowadays assessed by (visual) inspections at regular intervals. This approach cannot provide information about damage development in between inspections, leading to potential failure or...master thesis 2019
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Gasparis, Giorgos (author)Recently, Offshore Wind Turbines (OWT) have attracted great attention in an effort to make a shift from fossil-based energy sources towards an enhanced sustainable and renewable energy production. In order to achieve the renewables targets and reduce the cost of wind energy, OWTs are consistently increasing in size. Therefore, research has...master thesis 2019
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Leenders, Sjoerd (author)The growth of the offshore wind industry results in intensive usage of the sandy seabed in the North Sea, currently and in the coming decades. Large-scale bed forms are present in shallow seas with sandy beds such as the North Sea. The most dynamic bed forms are sand waves. Due to their dynamic behaviour, sand waves can interact within offshore...master thesis 2018
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Xiao, C. (author), Leeuwenburgh, O. (author), Lin, H.X. (author), Heemink, A.W. (author)This paper presents a non-intrusive subdomain POD-TPWL (SD POD-TPWL) for reservoir history matching through integrating domain decomposition (DD), proper orthogonal decomposition (POD), radial basis function (RBF) interpolation, and the trajectory piecewise linearization (TPWL). It is an efficient approach for model reduction and linearization...journal article 2018