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Doğan, D. (author), Leus, G.J.T. (author)We consider the problem of recovering complex-valued block sparse signals with unknown borders. Such signals arise naturally in numerous applications. Several algorithms have been developed to solve the problem of unknown block partitions. In pattern-coupled sparse Bayesian learning (PCSBL), each coefficient involves its own hyperparameter...journal article 2024
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Christodoulou, Anthony G. (author), Cruz, Gastao (author), Arami, A. (author), Weingärtner, S.D. (author), Artico, Jessica (author), Peters, Dana (author), Seiberlich, Nicole (author)Cardiovascular magnetic resonance (CMR) protocols can be lengthy and complex, which has driven the research community to develop new technologies to make these protocols more efficient and patient-friendly. Two different approaches to improving CMR have been proposed, specifically “all-in-one” CMR, where several contrasts and/or motion states...review 2024
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Verseput, Marien (author)Magnetic resonance imaging (MRI) is a non-invasive tool to image the body’s anatomy and physiology, but suffers from long scan times. Compressed Sensing (CS) is used to accelerate MRI scans by incoherently taking fewer measurements and using a nonlinear optimization algorithm to image the undersampled data. Convex optimization techniques are...master thesis 2023
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Yi, Weijia (author)This project develops a channel estimation technique for millimeter wave (mmWave) communication systems. Our method exploits the sparse structure in mmWave channels for low training overhead and accounts for the phase errors in the channel measurements due to phase noise at the oscillator. Specifically, in IEEE 802.11ad/ay-based mmWave systems,...master thesis 2023
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YAN, Chenyang (author)This study delves into the application of coded covers in enhancing Acoustic Vector Sensor (AVS) performance for sound source localization. We initially explored the use of a coded mask inspired by ultrasound imaging. However, our analysis indicated that the coded mask primarily acts as a scaling factor without substantial benefits for direction...master thesis 2023
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Subramani, Surya Natarajan (author)Radiation pattern measurements is a critical step in characterizing antennas before they are used in any system for a specific application. To identify any defects or to acquire the true radiation characteristics of the antenna under test, densely sampled measurements are desired. However, this results in a time and cost expensive measurement...master thesis 2023
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Sigurðsson, Snorri Þór (author)Regular maintenance of civil engineering structures is essential for their safety. Current maintenance regimes involve periodic inspections at regular time intervals. In the time between inspections, there can be a critical development in the structural integrity of a structure, which can be expensive to repair or could even lead to structural...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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Correas Serrano, A. (author), Petrov, N. (author), Gonzalez-Huici, Maria (author), Yarovoy, Alexander (author)This paper proposes a novel waveform, namely non-uniform OTFS (NU-OTFS), for joint radar and communication applications (Radcom) in multi-user/MIMO scenarios. Based on orthogonal time frequency space (OTFS) modulation, the proposed waveform is realized by using a non-uniform symplectic finite Fourier transform (NU-SFFT) to generate non...journal article 2023
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Roldan Montero, I. (author), Lamberti, Lucas (author), Fioranelli, F. (author), Yarovoy, Alexander (author)The problem of single-snapshot direction of arrival (DoA) estimation with antenna arrays has been considered. A sectorized approach based on Bayesian Compressive Sensing (BCS) has been proposed. In this method, the angular space is discretized, defining many non-overlapping small grids which cover the desired large angular space. First, a BCS...conference paper 2023
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Masoumi, H. (author), Verhaegen, M.H.G. (author), Myers, N.J. (author)Orthogonal matching pursuit (OMP) is a widely used greedy algorithm for sparse signal recovery in compressed sensing (CS). Prior work on OMP, however, has only provided reconstruction guarantees under the assumption that the columns of the CS matrix have equal norms, which is unrealistic in many practical CS applications due to hardware...conference paper 2023
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Siemons, M. E. (author), Hagenaar, M. (author), Adam, A.J.L. (author), Kohlhaas, R. (author)Recently a spectrometer concept has been invented which uses compressive sensing in combination with photonic crystal filters. Here we present an adaption of this concept in push-broom configuration for earth observation. This implementation allows for a compact design, while maintaining a high spatial resolution and high signal-to-noise...conference paper 2023
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He, Y. (author), Joseph, G. (author)This paper presents novel cascaded channel estimation techniques for an intelligent reflecting surface-aided multiple-input multiple-output system. Motivated by the channel angular sparsity at higher frequency bands, the channel estimation problem is formulated as a sparse vector recovery problem with an inherent Kronecker structure. We solve...conference paper 2023
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Lamberti, Lucas (author)Direction of Arrival (DoA) estimation is an important topic in radar application and has significant importance for advanced driver assistant systems in the automotive industry. While there is an increasing need for higher resolution and increased target detection and DoA estimation performance, such improvements often require increased hardware...master thesis 2022
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de Gijsel, Stefan L. (author), Vijn, A.R.P.J. (author), Tan, Reinier G. (author)This paper proposes an algorithm to localize a magnetic dipole using a limited number of noisy measurements from magnetic field sensors. The algorithm is based on the theory of compressed sensing, and exploits the sparseness of the magnetic dipole in space. Beforehand, a basis consisting of magnetic dipole fields belonging to individual...journal article 2022
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Karkalousos, D. (author), Noteboom, S. (author), Hulst, H. E. (author), Vos, F.M. (author), Caan, M.W.A. (author)Objective. Machine Learning methods can learn how to reconstruct magnetic resonance images (MRI) and thereby accelerate acquisition, which is of paramount importance to the clinical workflow. Physics-informed networks incorporate the forward model of accelerated MRI reconstruction in the learning process. With increasing network complexity,...journal article 2022
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Suvarna, Anusha Ravish (author), Koppelaar, Arie (author), Jansen, Feike (author), Wang, J. (author), Yarovoy, Alexander (author)High angular resolution is in high demand in automotive radar. To achieve a high azimuth resolution a large aperture antenna array is required. Although MIMO technique can be used to form larger virtual apertures, a large number of transmitter-receiver channels are needed, which is still technologically challenging and costly. To circumvent this...conference paper 2022
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Roldan Montero, I. (author), Fioranelli, F. (author), Yarovoy, Alexander (author)The problem of extended target cross-section estimation has been considered. A two-step method based on the Total Variation Compressive Sensing theory has been proposed to solve it. First, a coarse estimation of the target cross-section is performed with classical beamforming methods, and then Compressive Sensing algorithms have been applied...conference paper 2022
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Joseph, G. (author), Varshney, Pramod K. (author)In this paper, we consider the problem of estimating the states of a linear dynamical system whose inputs are jointly sparse and outputs at a few unknown time instants are missing. We model the missing data mechanism using a Markov chain with two states representing the missing and non-missing data. This mechanism with memory governed by the...conference paper 2022
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Ravish Suvarna, Anusha (author)In today's automotive applications, radar is widely used to estimate the target position and velocity with respect to the radar position. Estimating the position of the target in terms of range and velocity is fairly advanced and accurate. However, resolving two closely spaced targets in the azimuth domain which have the same range and relative...master thesis 2021