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Dondera, Alin (author)Masked Autoencoders (MAEs) represent a significant shift in self-supervised learning (SSL) due to their independence from augmentation techniques for generating positive (and/or negative) pairs as in contrastive frameworks. Their masking and reconstruction strategy also aligns well with SSL approaches in natural language processing. Most MAEs...master thesis 2024
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de Boer, Mitchell (author)Flow visualization is an important topic in many scientific domains and has been an active field of research for many years. Many different methods of analysis can be used in order to analyze flow, however recently big progress have been reported on the manifold learning algorithms for high-dimensional data. This thesis investigates the use of...master thesis 2024
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Vloeberghs, Victor (author)This thesis introduces a newly-developed turbulent combustion model, as a next step towards modelling hydrogen combustion in aircraft engines. The proposed model (FGM-ESF) merges the Flamelet Generated Manifold approach's tabulated chemistry with the Eulerian Stochastic Field method's statistical treatment of flame-turbulence interactions at the...master thesis 2024
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Kreza, Christina (author), Koffas, S. (author), Tajalli, Behrad (author), Conti, M. (author), Picek, S. (author)Recently, attackers have targeted machine learning systems, introducing various attacks. The backdoor attack is popular in this field and is usually realized through data poisoning. To the best of our knowledge, we are the first to investigate whether the backdoor attacks remain effective when manifold learning algorithms are applied to the...conference paper 2024
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Gupta, Mayank (author)Metal additive manufacturing has enabled great diversity and design freedom in heat exchanger design. However, these benefits cannot be adequately realised without optimizing its ancillary components as well, specifically the inlet and outlet manifolds. Optimizing the manifolds can significantly improve the flow distribution inside the heat...master thesis 2023
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van der Meulen, P.Q. (author)Whereas aberrating layers are typically viewed as an impediment to medical ultrasound imaging, they can, surprisingly, also be used to our benefit. As long as we can model the effect of an aberrating layer, we can utilize ‘model-based imaging’, the imaging technique explored throughout this thesis, to reconstruct ultrasound images where...doctoral thesis 2023
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Ramamohan, Krishnaprasad Nambur (author), Chepuri, Sundeep Prabhakar (author), Comesana, Daniel Fernandez (author), Leus, G.J.T. (author)In this work, we consider the self-calibration problem of joint calibration and direction-of-Arrival (DOA) estimation using acoustic sensor arrays. Unlike many previous iterative approaches, we propose solvers that can be readily used for both linear and non-linear arrays for jointly estimating the sensor gain, phase errors, and the source...journal article 2023
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Li, Mingwu (author), Jain, S. (author), Haller, George (author)Dynamical systems are often subject to algebraic constraints in conjunction with their governing ordinary differential equations. In particular, multibody systems are commonly subject to configuration constraints that define kinematic compatibility between the motion of different bodies. A full-scale numerical simulation of such constrained...journal article 2023
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Bao, Hesheng (author), Akargun, Hayri Yigit (author), Roekaerts, D.J.E.M. (author), Somers, Bart (author)In this work, an extension of the Flamelet Generated Manifold (FGM) method is developed suitable for igniting turbulent flames. To create the FGM, the strongly stretched flamelet equations (SSFE) are solved. Whereas in the standard basic method a single representative flamelet strain rate is used, in the new method a range of strain rates is...journal article 2023
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Simha, A. (author), Kaparin, Vadim (author), Mullari, Tanel (author), Kotta, Ulle (author)—This technical note addresses the problem of transforming a single-input–single-output discrete-time system into the extended observer form, which comprise a linear time-invariant observable component, and a nonlinear injection term, which depends on the input, output, and their forward shifts up to a finite order. Intrinsic necessary and...journal article 2023
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Legrand, Emiel (author)Conservative mechanical systems admit a symplectic structure. <br/>However, since real systems typically exhibit energy dissipation, this symplectic structure is often too restrictive for engineering purposes. <br/>Also in economic systems, dissipative phenomena are ubiquitous in the form of consumption and depreciation. <br/><br/>In this thesis...master thesis 2022
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Marting, Louis (author)Terahertz astronomy has been exceptionally unexplored until the last decades due to a technological gap, but exactly at these wavelengths the most distant galaxies appear very bright. Efficient instruments that are capable of spectrometry are essential in understanding the physics of these distant objects. Within the framework of this thesis, an...master thesis 2022
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Bougrimov, Denis (author)Sensitivity analysis and uncertainty quantification of nuclear reactors requires many expensive high-fidelity simulations. To approximate the dynamics of such a time and parameter dependent system efficiently and effectively, reduced order modelling (ROM) is used. In previous research, a ROM was constructed which used a combination of proper...master thesis 2022
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Stoellinger, Michael (author), Roekaerts, D.J.E.M. (author)The simple semi-empirical precursor soot model of Brookes and Moss based on the soot number density and soot mass concentration is adopted in a transported probability density function (PDF) method for turbulent diffusion flames. The gas phase chemistry is described by a flamelet generated manifold (FGM) based on the mixture fraction,...journal article 2022
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Mey, A. (author), Loog, M. (author)Semi-supervised learning is the learning setting in which we have both labeled and unlabeled data at our disposal. This survey covers theoretical results for this setting and maps out the benefits of unlabeled data in classification and regression tasks. Most methods that use unlabeled data rely on certain assumptions about the data...journal article 2022
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van Ginkel, G.J. (author)In this thesis we study the Symmetric Exclusion Process (SEP) and the Discrete Gaussian Free Field (DGFF) on compact Riemannian manifolds. In particular, we obtain the hydrodynamic limit and the equilibrium fluctuations of SEP and we show that the DGFF converges to its continuous counterpart. To define these discrete models, we construct grids...doctoral thesis 2021
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Kumar, Neel (author)In this thesis work, we strive to describe and apply the modelling methodology for simulating a turbulent jet diffusion flame stabilized behind a bluff body by applying flamelet generated manifold (FGM) model and steady diffusion flamelet model for predicting the pollutant emissions from the flame. The flame under consideration is a CH4/H2 (1:1)...master thesis 2021
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Morales Ubal, Cristopher (author)In reacting flows, detailed chemistry computations are usually avoided precomputing the thermochemical quantities as functions of a reduced set of variables such as the Flamelet Generated Manifold (FGM) approach[34]. Although it mitigates the calculations of detailed chemical mechanism, the memory requirement associated to store the lookup table...master thesis 2021
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Paricio Ezquerra, Daniel (author)Near-Earth Asteroids (NEAs) have attracted the attention of the scientific community in the last few years. Not only because of their importance to life on Earth but also their scientific potential and possible economic returns. This work explores the use of quasi-periodic orbits to bound the motion of NEAs close to the Earth’s vicinity for...master thesis 2021
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Tatay Sangüesa, Jose (author)The aim of this investigation is to improve the first stage of mission analysis on trajectories in the Circular Restricted Three-Body Problem (CR3BP). This will be achieved by developing a versatile tool that can optimize any transfer in the CR3BP in terms of ΔV and time of flight. Hence, the output will not be<br/>a single solution, but a...master thesis 2021