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Hunter, William (author)Atrial fibrillation is a common cardiovascular disease, affecting the regular beating of the heart through chaotic contraction of the heart's upper chambers. On its own, the condition—increasingly prevalent among the elderly—is not life threatening, but it leads to an increased risk of stroke and heart failure. As of yet, there is no consensus...master thesis 2022
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Keukeleire, Pia (author)Cell-free DNA (cfDNA) are DNA fragments originating from dying cells that enter the plasma. Uncontrolled cell death, for example caused by cancer, induces an elevated concentration of cfDNA. As a result, determining the cell type origins of cfDNA can provide information about an individual's health. This research looks into how to increase the...master thesis 2022
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Wijnands, Ruben (author)In recent years, the increase in brain research led to the development of large-scale brain imaging techniques. With large-scale brain imaging techniques, such as functional magnetic resonance imaging (fMRI), functional connectivity analyses have shown altered connectivity patterns in humans and mice with neurobiological disorders, such as...master thesis 2022
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Erol, A. (author), Soloukey, Chagajeg (author), Generowicz, Bastian (author), van Dorp, Nikki (author), Koekkoek, Sebastiaan (author), Kruizinga, P. (author), Hunyadi, Borbala (author)Functional ultrasound (fUS) indirectly measures brain activity by detecting changes in cerebral blood volume following neural activation. Conventional approaches model such functional neuroimaging data as the convolution between an impulse response, known as the hemodynamic response function (HRF), and a binarized representation of the input...journal article 2022
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Zhang, L. (author), Shao, J. (author), Zheng, Yikang (author), Wang, Y. (author), Slob, E.C. (author)Marchenko imaging can be seen as an internal multiple elimination scheme in imaging domain. By solving coupled Marchenko equations, the measured seismic data can be correctly redatumed to the subsurface with source positioned at subsurface and receivers positioned at acquisition surface. Then, the artefact-free image of the source point can...journal article 2022
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Abdi, Bahareh (author)Atrial fibrillation (AF) is a common age-related cardiac arrhythmia. AF is characterized by rapid and irregular electrical activity of the heart leading to a higher risk of stroke and heart failure. During AF, the upper chambers of the heart, called atria, experience chaotic electrical wave propagation. However, despite the various mechanisms...doctoral thesis 2021
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Vrijburg, Dominique (author)When objects are imaged, often aberrations slip into the captured images. Many techniques exist to remove part of those aberrations using hardware, software or a combination of those. This research will focus on Phase Diversity for Blind Multi-Frame Deconvolution. In Blind Multi-Frame Deconvolution both the object and the aberrations are...master thesis 2021
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de Bruijne, Bas (author)Ground based telescope imaging suffers from interference from the earth’s atmosphere. Fluctuations in the refractive index of the air delay incoming light randomly, resulting in blurred images. A deconvolution from wavefront sensing system is an adaptive optics system that measures the modes in which the light is corrupted (i.e. the wavefront)...master thesis 2021
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Shirmohammadi, F. (author), Draganov, D.S. (author), Hatami, Mohammad Reza (author), Weemstra, C. (author)Seismic interferometry (SI) refers to the principle of generating new seismic responses using crosscorrelations of existing wavefield recordings. In this study, we report on the use of a specific interferometric approach, called seismic interferometry by multidimensional deconvolution (SI by MDD), for the purpose of retrieving surface-wave...journal article 2021
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Liu, Xingchen (author)Structured illumination microscopy (SIM) is a kind of wide-field super resolution imaging technique which achieves the resolution improvement by exploiting the interference patterns to obtain the information out of the observable region in Fourier space. The resolution improvement in SIM is done by analyzing the obtained image and restored the...master thesis 2020
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Abdi, Bahareh (author), Hendriks, R.C. (author), van der Veen, A.J. (author), de Groot, N.M.S. (author)Background: Local activation time (LAT) annotation in unipolar electrograms is complicated by interference from nonlocal atrial activities of neighboring tissue. This happens due to the spatial blurring that is inherent to electrogram recordings. In this study, we aim to exploit multi-electrode electrogram recordings to amplify the local...journal article 2020
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Doelman, R. (author)Aberrations in optical systems, such as telescopes and microscopes, degrade the quality of the images that can be produced by these systems. For example, an object that is positioned out of focus produces a blurred image on a camera sensor and the turbulent air in the earth’s atmosphere reduces the imaging performance of telescopes. In this...doctoral thesis 2019
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van de Ketterij, wouter (author)Correction techniques, such as tangential iterative projections (TIP), were developed to reconstruct the image for the whole field of view. However, due to the three dimensional nature of biological tissues, induced aberrations are different throughout the field of view. This Master of Science thesis shows the development of four algorithms....master thesis 2019
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Merino Martinez, R. (author), Sijtsma, P. (author), Snellen, M. (author), Finez, A. (author), Herold, G. (author), Malgoezar, A.M.N. (author), Pereira, A. (author), Sarradj, E. (author), Simons, D.G. (author)Phased microphone arrays have become a well-established tool for performing aeroacoustic measurements in wind tunnels (both open-jet and closed-section), flying aircraft, and engine test beds. This paper provides a review of the most well-known and state-of-the-art acoustic imaging methods and recommendations on when to use them. Several...journal article 2019
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- Shirmohammadi, F. (author), Weemstra, C. (author), Draganov, D.S. (author), Wapenaar, C.P.A. (author) poster 2019
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Luesutthiviboon, S. (author), Malgoezar, A.M.N. (author), Merino Martinez, R. (author), Snellen, M. (author), Sijtsma, P. (author), Simons, D.G. (author)The recently introduced high-resolution (HR)-CLEAN-SC algorithm for acoustic imaging provides ‘super-resolution’, i.e. the ability to discern sound sources located closer than the Rayleigh resolution limit. This is achieved by allowing the source markers to be relocated from the actual source locations within a certain constraint to avoid the...journal article 2019
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Sridharan, Sudarshan (author)The research in resolving the smaller scales of turbulence has gained significant attention in recent years, owing to the advancements in the measurement techniques. High resolution experimental studies are required to investigate high Reynolds number flows where the scales of turbulence are very small. This is of particular importance in...master thesis 2018
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Wilding, D. (author)The goal of this thesis, called Physical and Computational Approaches to Aberration Correction In Fluorescence Microscopy, concerns itself with the development of new techniques to control adaptive fluorescence microscopes, so that they can adapt and image with increased resolution, contrast and speed inside complex three-dimensional biological...doctoral thesis 2018
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Sijtsma, P. (author), Brouwer, Harry (author)Unequally spaced transducer rings make it possible to extend the range of detectable azimuthal modes. The disadvantage is that the response of the mode detection algorithm to a single mode is distributed over all detectable modes, similarly to the Point Spread Function of Conventional Beamforming with microphone arrays. With multiple modes...journal article 2018
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Hartstra, I.E. (author), Almagro Vidal, C. (author), Wapenaar, C.P.A. (author)Virtual Green's functions obtained by seismic interferometry (SI) can provide valuable reflectivity data that can complement tomographic inversion schemes. However, virtual reflections are affected by illumination irregularities that are typical of earthquake-induced wavefields recorded by the receiver array. As a consequence, irregular...journal article 2018