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Verhelst, H.M. (author)Wrinkles are ubiquitous in the world around us. In our daily lives, we encounter wrinkles in various forms, whether in our clothes or on our skin. Wrinkles emerge as a result of a delicate interplay between bending, membrane, and foundation stiffness contributions within membranes. While experimental investigations provide insights into the...doctoral thesis 2024
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Yu, Ying-Ying (author), Li, Xin (author), Ji, Y. (author)Bézier and B-spline curves are foundational tools for curve representation in computer graphics and computer-aided geometric design, with their intersection computation presenting a fundamental challenge in geometric modeling. This study introduces an innovative algorithm that quickly and effectively resolves intersections between Bézier and B...journal article 2024
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Verhelst, H.M. (author), Weinmüller, P. (author), Mantzaflaris, A. (author), Takacs, T. (author), Toshniwal, D. (author)In order to perform isogeometric analysis with increased smoothness on complex domains, trimming, variational coupling or unstructured spline methods can be used. The latter two classes of methods require a multi-patch segmentation of the domain, and provide continuous bases along patch interfaces. In the context of shell modelling,...journal article 2024
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Andreadis, Georgios (author), Mulder, Joas I. (author), Bouter, P.A. (author), Bosman, P.A.N. (author), Alderliesten, T. (author)The transformation model is an essential component of any deformable image registration approach. It provides a representation of physical deformations between images, thereby defining the range and realism of registrations that can be found. Two types of transformation models have emerged as popular choices: B-spline models and mesh models....conference paper 2024
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Bogaerts, Charlie (author)This study aims to quantify the aerodynamic behaviour of fixed pitch rotors with a diameter of 12.7 cm in axial descent, and its contribution to the attitude oscillations found for quadcopters under similar flight conditions. Wind tunnel tests are performed with an isolated rotor, as well as a complete quadcopter mounted inside a gimbal that...master thesis 2023
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Sindy, Ferhat (author)Computational Fluid Dynamics (CFD) offers numerous benefits, notably the ability to study flows that are challenging or costly to investigate using experiments. A central challenge in CFD lies in simulating fluid flow around complex geometries. Additionally, the governing equations follow conservation laws. This thesis aims to establish the...master thesis 2023
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Mulder, Joas (author)Deformable Image Registration (DIR) is a medical imaging process involving the spatial alignment of two or more images using a transformation model that can account for non-rigid deformations. B-spline-based transformation models have emerged as a common approach to express such spatial alignments. However, without additional measures, their...master thesis 2023
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Takacs, Thomas (author), Toshniwal, D. (author)Isogeometric Analysis generalizes classical finite element analysis and intends to integrate it with the field of Computer-Aided Design. A central problem in achieving this objective is the reconstruction of analysis-suitable models from Computer-Aided Design models, which is in general a non-trivial and time-consuming task. In this article,...journal article 2023
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Jin, J. (author), Li, Z. (author)Empirical mode decomposition (EMD) lacks a strong theoretical support although extensively applied. We propose a theoretical framework for a succinct EMD in this work, with the assumption of invariant extrema locations for one IMF extraction. We define the envelope mean filter (EMF) and prove that the filter matrix satisfies five properties....journal article 2023
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de Koning, B. (author), Heemels, A.N.M. (author), Adam, A.J.L. (author), Möller, M. (author)Algorithmic differentiable ray tracing is a new paradigm that allows one to solve the forward problem of how light propagates through an optical system while obtaining gradients of the simulation results with respect to parameters specifying the optical system. Specifically, the use of algorithmically differentiable non-sequential ray tracing...journal article 2023
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Lai, F. (author), Shiau, Jim (author), Keawsawasvong, Suraparb (author), Chen, Fuquan (author), Banyong, Rungkhun (author), Seehavong, Sorawit (author)This study presents a hybrid framework to predict stability solutions of buried structures under active trapdoor conditions in natural clays with anisotropy and heterogeneity by combining physics-based and data-driven modeling. Finite-element limit analysis (FELA) with a newly developed anisotropic undrained shear (AUS) failure criterion is...journal article 2023
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Schmidt, Mathias (author), Noel, L.F.P. (author), Doble, Keenan (author), Evans, John A. (author), Maute, Kurt (author)This paper presents an immersed, isogeometric finite element framework to predict the response of multi-material, multi-physics problems with complex geometries using locally refined discretizations. To circumvent the need to generate conformal meshes, this work uses an extended finite element method (XFEM) to discretize the governing...journal article 2023
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Toshniwal, D. (author), Villamizar, Nelly (author)Multivariate piecewise polynomial functions (or splines) on polyhedral complexes have been extensively studied over the past decades and find applications in diverse areas of applied mathematics including numerical analysis, approximation theory, and computer aided geometric design. In this paper we address various challenges arising in the...journal article 2023
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Ruiter, Stijn (author)<br/>The Material Point Method (MPM) is a numerical method primarily used in the simulation of large deforming or multi-phase materials. An example of such a problem is a landslide or snow simulation. The MPM uses Lagrangian particles (material points) to store the interested physical quantities. These particles can move freely in the spatial...master thesis 2022
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Dijkstra, Kevin (author)Existence of commuting THB-spline projectors is of importance in the field of numerical mathematics. These projectors are required to show that numerical solutions to the abstract Hodge Laplace problem are stable and consistent. We have introduced a local THB-spline projector based on Bezier projection, that commutes in the one-dimensional case....master thesis 2022
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Kanhai, Prawien (author)In recent years the popularity of VTOL (Vertical Take-Off and Landing) drones has increased significantly. Due to their hybrid design, these drones can take off and land vertically and fly horizontally, enabling them to land in difficult terrain and have a more extensive range than the Quadcopter counterpart. However, this hybrid design also...master thesis 2022
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de Koning, Bart (author)Differentiable ray-tracing is an exciting new development in computer graphics to approach all sorts of 3D scene design problems by obtaining gradients of renders produced by ray-tracing with respect to parameters that define the scene. These gradients can then be incorporated in a gradient-descent type optimization pipeline.<br/><br/>One such...master thesis 2022
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Bosma, Douwe (author)An isogeometric finite element method for incompressible fluid film equations is presented. The method can be applied to numerically model the behaviour of thin cellular membranes, such as lipid bilayers. The membranes are represented by infinitely thin closed surfaces. Both the surface parametrization and analysis are based on state-of-the-art...master thesis 2022
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Toshniwal, D. (author)Given an unstructured mesh consisting of quadrilaterals and triangles (we allow both planar and non-planar meshes of arbitrary topology), we present the construction of quadratic splines of mixed smoothness — C<sup>1</sup> smooth away from the unstructured regions of T and C<sup>0</sup> smooth otherwise. The splines have several useful B...journal article 2022
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Kumar, Gulshan (author), Saha, Rahul (author), Conti, M. (author), Thomas, Reji (author), Devgun, Tannishtha (author), Rodrigues, Joel J.P.C. (author)Internet-of-Thing (IoT) faces various security attacks. Different solutions exist to mitigate the intrusion problems. However, the existing solutions lack behind in dealing with heterogeneity of attack sources and features. The future anticipated demand of devices' connections also urge the need of new solutions addressing the concerns of...journal article 2022