Searched for: subject%3A%22symmetry%22
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Arnoldus, Matthijs (author)
Computational efficiency is essential for large-scale mathematical optimisation problems, such as the generation expansion planning problem, to be practically applicable. In linear programming solvers, crossover is frequently a bottleneck when solving optimisation problems. This study aims at determining why crossover is a bottleneck in solving...
master thesis 2024
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Slebioda, Marek (author)
Offshore wind turbines have seen a significant increase in size over the past decades. A critical consequence of this increase in size is a substantial increase in the torque transferred from the wind turbine rotor. This leads to the necessity of larger and heavier drivetrains to adhere to structural failure requirements and subsequently to...
master thesis 2023
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Huang, J. (author), Stoter, J.E. (author), Nan, L. (author)
Symmetry widely exists in nature and man-made shapes, but it is unavoidably distorted during the process of growth, design, digitalization, and reconstruction steps. To enhance symmetry, traditional methods follow the detect-then-symmetrize paradigm, which is sensitive to noise in the detection phase, resulting in ambiguities for the...
journal article 2023
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Slebioda, Marek (author), Giele, R.J.P. (author), Langelaar, Matthijs (author)
This paper presents a density based topology optimization method for infinite fatigue life constraints of non-proportional load cases, with a specific focus on parts with cyclic symmetry. Considering non-proportional loads in topology optimization significantly broadens the types of design problems that can be handled. The method estimates...
journal article 2023
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Wapenaar, C.P.A. (author), Slob, E.C. (author)
Inspired by recent developments in wave propagation and scattering experiments with parity-time (PT) symmetric materials, we discuss reciprocity and representation theorems for 3D inhomogeneous PT-symmetric materials and indicate some applications. We start with a unified matrix-vector wave equation which accounts for acoustic, quantum...
journal article 2022
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Iannini, L. (author), Comite, D. (author), Pierdicca, N. (author), López-Dekker, Paco (author)
Bistatic scattering from rough surfaces is typically approached through the analysis of the scattered field in the conventional H and V polarization basis, which coincides with the zenith and azimuth unit vectors in a spherical reference frame. This study delves into the impacts of different choices of the transmit and receive linear basis on...
journal article 2022
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van der Toorn, R. (author)
Legendre’s equation is key in various branches of physics. Its general solution is a linear function space, spanned by the Legendre functions of the first and second kind. In physics, however, commonly the only acceptable members of this set are Legendre polynomials. The quantization of the eigenvalues of Legendre’s operator is a consequence of...
journal article 2022
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van Gulik, Quirijn (author)
Representation theory is a branch in mathematics that studies group homomorphisms between a group and the automorphism group of a vector space. A special representation that every group has is the regular representation. This representation permutes all elements of the group in a vector space which dimension is equal to the order of the group....
bachelor thesis 2021
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Fleuren, Jules (author)
Vector spherical harmonics are a set of basis functions for vector fields derived from the spherical harmonic functions. They are commonly used in spectral methods in certain areas of applied mathematics. In most of the existing literature they are defined in a way that is heavily dependent on the used coördinate system. In this thesis we define...
bachelor thesis 2021
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Dupont, José (author)
This thesis is divided into five parts (covering chapter 1–5), that together try to give the reader a basic understanding of the symmetries of and the mathematical structure behind the standard model. The first two chapters cover some Lie and representation theory of the Lie groups U(1), SU(2) and SU(3), which play a central role in the standard...
bachelor thesis 2021
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Karaiskou, Antigoni (author), Turrin, M. (author), Tenpierik, M.J. (author)
Speech intelligibility is crucial in many spaces, yet designers often fail to predict the acoustic shortcomings of certain design choices. This paper builds on the potential of hybrid surface treatments showcasing low-frequency absorption to control background noise levels and high-frequency diffusion to improve speech-in-noise perception to...
conference paper 2020
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Kraaij, R.C. (author), Lazarescu, Alexandre (author), Maes, Christian (author), Peletier, Mark (author)
We develop a formalism to discuss the properties of GENERIC systems in terms of corresponding Hamiltonians that appear in the characterization of large-deviation limits. We demonstrate how the GENERIC structure naturally arises from a certain symmetry in the Hamiltonian, which extends earlier work that has connected the large-deviation...
journal article 2020
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Keustermans, William (author), Huysmans, T. (author), Schmelzer, Bert (author), Sijbers, Jan (author), Dirckx, J.J. (author)
In this paper, we investigate the heating function of the nasal cavity qualitatively, using a high-quality, large-scale statistical shape model. This model consists of a symmetrical and an asymmetrical part and provides a new and unique way of examining changes in nasal heating function resulting from natural variations in nasal shape (as...
journal article 2020
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Daalman, W.K. (author), Sweep, E. (author), Laan, L. (author)
A bottom-up route towards predicting evolution relies on a deep understanding of the complex network that proteins form inside cells. In a rapidly expanding panorama of experimental possibilities, the most difficult question is how to conceptually approach the disentangling of such complex networks. These can exhibit varying degrees of...
review 2020
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Mulder, Ike (author)
Packing problems are concerned with filling the space with copies of a certain object, so that the least amount of space stays unoccupied. The famous Kepler conjecture asserts that the cannonball packing of spheres is the most efficient packing achievable, and was recently formally proven by Hales.<br/><br/>Dostert, Guzman, Oliveira Filho and...
master thesis 2019
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Nuijts, Ivar (author)
This thesis presents a transformable metamaterial, inspired by origami. Generally, metamaterials are build up following the periodicity of Bravais lattices. This study aims to design a structure not following the Bravais lattices, but rather a different type of symmetry which tiles a sphere, in order to expand on current design studies. In this...
master thesis 2019
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van Loenhout, Steffie (author)
In order to handle the increase in baggage units, KLM needs to optimize the outbound baggage handling process. This study focuses on accurately modeling the outbound baggage handling process while minimizing the number of employees working on this process. The results are based upon data on the outbound baggage handling process at KLM in 2018....
master thesis 2019
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Tümer, N. (author), Arbabi, V. (author), Gielis, Willem Paul (author), de Jong, Pim A. (author), Weinans, Harrie (author), Tuijthof, Gabrielle J.M. (author), Zadpoor, A.A. (author)
The bones forming the talocrural joint (TCJ) and subtalar joint (STJ) are often assumed to be bilaterally symmetric. Therefore, the contralateral limb (i.e. the fibula, tibia, calcaneus and talus) is used as a template or an intra-subject control in clinical and research practice. However, the validity of the symmetry assumption is...
journal article 2019
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Varjas, D. (author), Lau, A. (author), Pöyhönen, K.K. (author), Akhmerov, A.R. (author), Pikulin, Dmitry I. (author), Fulga, Ion Cosma (author)
We construct a two-dimensional higher-order topological phase protected by a quasicrystalline eightfold rotation symmetry. Our tight-binding model describes a superconductor on the Ammann-Beenker tiling hosting localized Majorana zero modes at the corners of an octagonal sample. In order to analyze this model, we introduce Hamiltonians...
journal article 2019
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Varjas, D. (author), Rosdahl, T.O. (author), Akhmerov, A.R. (author)
Symmetry is a guiding principle in physics that allows us to generalize conclusions between many physical systems. In the ongoing search for new topological phases of matter, symmetry plays a crucial role by protecting topological phases. We address two converse questions relevant to the symmetry classification of systems: is it possible to...
journal article 2018
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