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Kluwer, Thomas (author)Global warming has caused an increasing demand for renewable energy. Currently, 50% of the renewable energy is provided by wind and solar combined. However, these renewable energy sources are highly volatile. Wave energy converters can provide a stable renewable energy source. Previous research has contributed to understanding various combined...master thesis 2023
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van Engen, Femke (author)Meditation is a contemplative practice that is believed to entail attentional and emotional regulation. One of the biggest challenges in developing personalized, accessible healthcare options with meditation is finding understandable features that signify whether someone is meditating. Specifically, there is no consensus on a feature resulting...master thesis 2022
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Ureña Baltierra, Gerardo (author)Mimetic formulations, also known as structure-preserving methods, are numerical schemes that preserve fundamental properties of the continuous differential operators at a discrete level. Additionally, they are well-known for satisfying constraints such as conservation of mass or momentum. <br/><br/>In the present work, a Mimetic Spectral Element...master thesis 2022
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Verlinde, Lander (author)This thesis uses the method of interlacing polynomials to study the behaviour of eigenvalues of a matrix after a rank-one update. Specifically, interlacing polynomials, common interlacing and interlacing families are exhaustively studied. These are excellent tools to find bounds on the eigenvalues of updated matrices by keeping track of how they...bachelor thesis 2022
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Hou, Jue (author), Liu, Zhou (author), Wang, Shaorong (author), Chen, Zhe (author), Xie, Wei (author), Fang, Cheng (author), Wei, Xinchi (author), Popov, M. (author)Supplementary control (SC) technology is widely leveraged by power supply companies in active distribution networks (ADNs) to improve their stability and dynamic characteristics. Yet, the existed SCs are generally implemented from inside the converter controllers of distributed generators (DGs) or active loads, so there is a need to redesign...journal article 2022
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Prins, Peter J. (author), Wahls, S. (author)We propose a numerical algorithm that computes the eigenvalues of the Korteweg–de Vries equation (KdV) from sampled input data with vanishing boundary conditions. It can be used as part of the Non-linear Fourier Transform (NFT) for the KdV equation. The algorithm that we propose makes use of Sturm-Liouville (SL) oscillation theory to guaranty...journal article 2022
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Yue, D. (author), Baldi, S. (author), Cao, Jinde (author), De Schutter, B.H.K. (author)This article addresses the continuous-time distributed optimization of a strictly convex summation-separable cost function with possibly nonconvex local functions over strongly connected digraphs. Distributed optimization methods in the literature require convexity of local functions, or balanced weights, or vanishing step sizes, or algebraic...journal article 2022
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Dahlgren, F.S. (author), Gershkoff, Zachary (author), Hogben, Leslie (author), Motlaghian, Sara (author), Young, Derek (author)A hollow matrix described by a graph G is a real symmetric matrix having all diagonal entries equal to zero and with the off-diagonal entries governed by the adjacencies in G. For a given graph G, the determination of all possible spectra of matrices associated with G is the hollow inverse eigenvalue problem for G. Solutions to the hollow...journal article 2022
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Huang, N. (author), Ma, Yutao (author)We use tridiagonal models to study the limiting behavior of β-Laguerre and β-Jacobi ensembles, focusing on the limiting behavior of the extremal eigenvalues and the central limit theorem for the two ensembles. For the central limit theorem of β-Laguerre ensembles, we follow the idea in [1] while giving a modified version for the generalized...journal article 2022
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He, Y. (author), Coutino, Mario (author), Isufi, E. (author), Leus, G.J.T. (author)In this work, we focus on partitioning dynamic graphs with two types of nodes (bi-colored), though not necessarily bipartite graphs. They commonly appear in communication network applications, e.g., one color being base stations, the other users, and the dynamic process being the varying connection status between base stations and moving...conference paper 2022
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He, Yanbin (author)Graphs can be models for many real-world systems, where nodes indicate the entities and edges indicate the pairwise connections in between. In various cases, it is important to detect informative subsets of nodes such that the nodes within the subsets are ’closer’ to each other. For example, in a cellular network, determining appropriate node...master thesis 2021
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Chu, Jifeng (author), Marynets, K. (author)The aim of this paper is to study one class of nonlinear differential equations, which model the Antarctic circumpolar current. We prove the existence results for such equations related to the geophysical relevant boundary conditions. First, based on the weighted eigenvalues and the theory of topological degree, we study the semilinear case....journal article 2021
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Yue, D. (author), Baldi, S. (author), Cao, Jinde (author), Li, Qi (author), De Schutter, B.H.K. (author)In this article, the time-varying formation and time-varying formation tracking problems are solved for linear multiagent systems over digraphs without the knowledge of the eigenvalues of the Laplacian matrix associated with the digraph. The solution to these problems relies on an approach that generalizes the directed spanning tree (DST)...journal article 2021
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Dwarka, V.N.S.R. (author), Vuik, Cornelis (author)In researching the Helmholtz equation, the focus has either been on the accuracy of the numerical solution (pollution) or the acceleration of the convergence of a preconditioned Krylov-based solver (scalability). While it is widely recognized that the convergence properties can be investigated by studying the eigenvalues, information from the...journal article 2021
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Wang, F. (author), Leus, G.J.T. (author)In this paper we consider the problem of joint wideband spectrum sensing and direction-of-arrival (DoA) estimation, where a number of uncorrelated narrowband sources spread over a wide frequency band impinge on a sparse linear array (SLA). To overcome the sampling rate bottleneck for wideband spectrum sensing, we rely on sub-Nyquist sampling for...conference paper 2021
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Habben Jansen, A.C. (author)Naval ships are designed to operate in hostile environments. As such, vulnerability reduction is an important aspect that needs to be assessed during the design. With the increased interest in electrification and automation on board naval ships, the vulnerability of distributed systems has become a major topic of interest. However, assessing...doctoral thesis 2020
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Seo, Jeongwon (author), Abdel-Khalik, Hany (author), Perko, Z. (author)This paper presents an algorithm for completing sensitivity analysis that respects linear constraints placed on the associated model’s input parameters. Any sensitivity analysis (linear or nonlinear, local or global) focuses on measuring the impact of input parameter variations on model responses of interest, which may require the analyst to...journal article 2020
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Coutino, Mario (author), Isufi, E. (author), Maehara, Takanori (author), Leus, G.J.T. (author)In this article, we explore the state-space formulation of a network process to recover from partial observations the network topology that drives its dynamics. To do so, we employ subspace techniques borrowed from system identification literature and extend them to the network topology identification problem. This approach provides a unified...journal article 2020
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Jain, V. (author), Zhang, Y. (author), Palha da Silva Clérigo, A. (author), Gerritsma, M.I. (author)Given a sequence of finite element spaces which form a de Rham sequence, we will construct dual representations of these spaces with associated differential operators which connect these spaces such that they also form a de Rham sequence. The dual representations also need to satisfy the de Rham sequence on the domain boundary. The matrix...journal article 2020
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Non-linear dynamic response of a beam using an impulse response method based on linear complex modesKok, Roy (author)The purpose of this thesis is to formulate and test a computational method, based on linear complex modes, to calculate the dynamic response of a beam with a boundary dashpot excited by a non-linear response-dependent dissipative force. This impulse response method is a time-stepping method which iteratively approximates the non-linear force by...master thesis 2019